Alpha-1 Antitrypsin Deficiency

Mendelian MONDO:0013282 Pathograph 31 Show in embeddings browser Genetic Lung Diseases Hereditary Metabolic Diseases

Alpha-1 antitrypsin deficiency is an autosomal codominant disorder caused by pathogenic variants in SERPINA1, which encodes the principal circulating inhibitor of neutrophil elastase. The common severe Z allele causes the mutant protein to misfold and polymerize within hepatocytes, producing both a loss of circulating antiprotease activity and a toxic gain-of-function from hepatic polymer accumulation. Inadequate antiprotease protection lets neutrophil elastase degrade alveolar elastin, causing early-onset panacinar emphysema (accelerated by smoking), while the retained hepatic polymers can cause cirrhosis and hepatocellular carcinoma.

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1
Inheritance
10
Pathophys.
1
Histopath.
9
Phenotypes
3
Gaps
31
Pathograph
2
Genes
10
Medical Actions
1
Differentials
2
Datasets
3
Trials
2
Models
60
References
2
Deep Research
🏷

Classifications

Harrison's Part
RESPIRATORY GASTROINTESTINAL GENETICS ENVIRONMENT DISEASE
Mechanistic Nosology
proteotoxic disease
👪

Inheritance

1
Autosomal codominant inheritance HP:0032113
SERPINA1 alleles are expressed codominantly. When both parents carry one pathogenic allele, each sibling has a 25% chance of inheriting two pathogenic alleles, a 50% chance of being heterozygous, and a 25% chance of inheriting neither allele.
autosomal codominant inheritance
Show evidence (2 references)
PMID:20301692 SUPPORT Other
"AATD is inherited in an autosomal codominant manner."
GeneReviews directly states the autosomal codominant inheritance pattern.
PMID:20301692 SUPPORT Other
"If both parents are heterozygous for one SERPINA1 pathogenic variant (e.g., PI*MZ), each sib of an affected individual has a 25% chance of being affected (PI*ZZ), a 50% chance of being heterozygous (PI*MZ), and a 25% chance of inheriting neither of the pathogenic variants (PI*MM)."
GeneReviews gives the recurrence risks for two heterozygous parents.
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Discussions and Knowledge Gaps

3
Which molecular intermediates connect systemic AAT deficiency to the neutrophilic inflammation and fat necrosis of AATD-associated panniculitis?
KNOWLEDGE GAP OPEN gap_aatd_cutaneous_mechanism
Attached to
pathophysiology#Neutrophilic Subcutaneous Inflammation
Human biopsy establishes the lesion, but the cached disease-specific evidence does not justify a more specific protease-causal edge.
Show evidence (1 reference)
PMID:33516773 SUPPORT Other
"Evidence regarding management is limited to case reports and small case series."
The systematic review documents the limited evidence base for this rare manifestation.
Which genetic and environmental modifiers determine why only some people with the Pi*ZZ genotype progress to end-stage liver disease?
KNOWLEDGE GAP OPEN gap_aatd_variable_penetrance
Attached to
pathophysiology#Hepatocyte Injury pathophysiology#Hepatic Stellate Cell Activation
Variable progression limits individual risk prediction and stratification for liver-directed therapy.
Show evidence (1 reference)
PMID:28752441 SUPPORT Other
"Since not all patients with the same homozygous PIZZ genotype develop end-stage disease, it is hypothesized that there is likely to be a strong influence of genetic and environmental modifiers of the injury cascade and of the fibrotic response."
The review explicitly identifies unexplained modifier effects on liver-disease progression.
How faithfully do current hepatocyte and mouse systems predict the combined human pulmonary and hepatic disease, rather than only the hepatic PI*Z UPR arm?
HUMAN MODEL MISMATCH OPEN gap_aatd_model_scope
Attached to
pathophysiology#Hepatic Protein Aggregation pathophysiology#Protease-Antiprotease Imbalance in Lung
Current models clarify hepatocyte UPR biology but do not establish that one system recapitulates both target organs or human clinical variability.
Show evidence (1 reference)
PMID:35621045 SUPPORT Other
"It has been unclear whether PI*Z AAT elicits liver cell UPR, due in part to limitations of current cellular and animal models."
The study explicitly motivates new models because existing cellular and animal systems are limited.
⚙

Pathophysiology

10
Pulmonary Neutrophil Recruitment
Pulmonary inflammatory stimuli recruit neutrophils from the circulation to affected tissue.
neutrophil CL:0000775 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves neutrophil (CL:0000775). CL:0000775 is a cell type from the Cell Ontology.
leukocyte migration GO:0050900 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves leukocyte migration (GO:0050900). GO:0050900 is a biological process from the Gene Ontology.
Downstream
Pulmonary Neutrophil Degranulation Recruited neutrophils activate and degranulate in inflamed pulmonary tissue.
Show evidence (1 reference)
PMID:29258516 SUPPORT Other
"Once inflammatory trigger develops in peripheral tissues, neutrophils are rapidly recruited toward to the anatomical site of inflammation."
The respiratory review directly describes recruitment to inflamed tissue.
Pulmonary Neutrophil Degranulation
Activated neutrophils degranulate and release inflammatory proteases, including neutrophil elastase.
neutrophil CL:0000775 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves neutrophil (CL:0000775). CL:0000775 is a cell type from the Cell Ontology.
neutrophil degranulation GO:0043312 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves neutrophil degranulation (GO:0043312). GO:0043312 is a biological process from the Gene Ontology.
Downstream
Neutrophil Elastase Activity Degranulation releases neutrophil elastase into the extracellular compartment.
Show evidence (1 reference)
PMID:29258516 SUPPORT Other
"Neutrophil degranulation is responsible for the release of several inflammatory mediators, such as neutrophil elastase, cathepsin G, and proteinase 3"
The respiratory review directly identifies neutrophil elastase as a degranulation product.
Neutrophil Elastase Activity
Neutrophil elastase is the effector protease left insufficiently inhibited when functional AAT is deficient.
serine-type endopeptidase activity GO:0004252 Gene Ontology (GO) Relation: this pathophysiological event involves this molecular function This pathophysiological event involves increased serine-type endopeptidase activity (GO:0004252). GO:0004252 is a molecular function from the Gene Ontology. ↑ INCREASED
Downstream
Protease-Antiprotease Imbalance in Lung Neutrophil-elastase activity becomes insufficiently opposed when functional AAT is deficient.
Show evidence (1 reference)
PMID:40967767 SUPPORT Human Clinical
"Alvelestat is an oral inhibitor of neutrophil elastase (NE) in development as a novel approach to AATD therapy."
The Phase 2 report identifies neutrophil elastase as a therapeutic effector target in AATD.
Protease-Antiprotease Imbalance in Lung
Reduced functional AAT disrupts protease-antiprotease homeostasis and decreases neutrophil-elastase inhibition.
SERPINA1 hgnc:8941 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves SERPINA1 (hgnc:8941). hgnc:8941 is a gene from the HUGO Gene Nomenclature Committee.
serine-type endopeptidase inhibitor activity GO:0004867 Gene Ontology (GO) Relation: this pathophysiological event involves this molecular function This pathophysiological event involves decreased serine-type endopeptidase inhibitor activity (GO:0004867). GO:0004867 is a molecular function from the Gene Ontology. ↓ DECREASED
Downstream
Alveolar Tissue Destruction Reduced functional AAT leaves neutrophil elastase insufficiently inhibited, disrupting protease-antiprotease homeostasis and promoting elastin breakdown in the lung interstitium.
Bronchiectasis Protease-antiprotease imbalance in AATD contributes to chronic obstructive lung disease phenotypes that include bronchiectasis.
Show evidence (1 reference)
PMID:39980299 SUPPORT Other
"Reduced levels of functional AAT disrupt the protease-antiprotease homeostasis, leading to a loss of neutrophil elastase inhibition and the breakdown of elastin within the lung interstitium."
The review directly supports the protease-antiprotease imbalance and its tissue consequence.
Hepatic Protein Aggregation
In PiZZ individuals, mutant Z-AAT misfolds during biogenesis and approximately 85% is retained within hepatocytes rather than secreted, producing hepatic accumulation and limiting access to the circulation.
hepatocyte CL:0000182 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves hepatocyte (CL:0000182). CL:0000182 is a cell type from the Cell Ontology.
SERPINA1 hgnc:8941 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves SERPINA1 (hgnc:8941). hgnc:8941 is a gene from the HUGO Gene Nomenclature Committee.
Experimental models
CRISPR-engineered Huh7.5Z hepatocyte cell line CELL LINE PI*Z AAT expression produces the hepatocellular proteostasis lesion.
Downstream
ER Stress and Unfolded Protein Response Intracellular Z-AAT retention provokes hepatocyte proteostasis stress.
Neutrophilic Subcutaneous Inflammation Severe AATD can also produce panniculitis through a cutaneous mechanism whose intermediates remain incompletely established.
Granulomatosis with Polyangiitis AATD is associated with C-ANCA-positive granulomatosis with polyangiitis through unresolved intermediates.
Protease-Antiprotease Imbalance in Lung Hepatocyte retention of mutant AAT limits circulating functional AAT, leaving the lung exposed to protease-mediated tissue injury.
Show evidence (2 references)
PMID:28752441 SUPPORT Other
"These homozygous individuals synthesize large quantities of a1AT mutant Z protein in the liver, but the mutant protein folds improperly during biogenesis and approximately 85% of the molecules are retained within the hepatocytes rather than appropriately secreted."
Teckman & Blomenkamp quantify hepatic Z-AAT retention (~85%) and link it directly to deficient circulating AAT, supporting the hepatic-aggregation pathway as the proximal cause of both liver and lung disease.
PMID:39440224 SUPPORT Human Clinical
"Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by the misfolding and accumulation of the mutant variant of alpha-1 antitrypsin (AAT) within hepatocytes, which limits its access to the circulation and exposes the lungs to protease-mediated tissue damage."
2024 hepatology characterization study confirms the misfolding/hepatocyte-accumulation model of AATD pathogenesis.
ER Stress and Unfolded Protein Response
Intracellular mutant Z-AAT initiates an ER-stress-associated hepatocyte injury cascade involving unfolded-protein-response signaling.
hepatocyte CL:0000182 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves hepatocyte (CL:0000182). CL:0000182 is a cell type from the Cell Ontology.
response to endoplasmic reticulum stress GO:0034976 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves response to endoplasmic reticulum stress (GO:0034976). GO:0034976 is a biological process from the Gene Ontology. endoplasmic reticulum unfolded protein response GO:0030968 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves endoplasmic reticulum unfolded protein response (GO:0030968). GO:0030968 is a biological process from the Gene Ontology.
Experimental models
CRISPR-engineered Huh7.5Z hepatocyte cell line CELL LINE The line directly reports UPR activation and chaperone induction.
Downstream
Hepatocyte Injury ER-stress-associated signaling proceeds to mitochondrial and caspase-linked hepatocyte injury.
Show evidence (1 reference)
PMID:28752441 SUPPORT Other
"This intracellular death cascade appears to involve ER stress, mitochondrial depolarization, and caspase cleavage, and is possibly linked to autophagy and redox injury."
The mechanistic review places ER stress within the intracellular hepatocyte injury cascade.
Hepatocyte Injury
Chronic intracellular Z-AAT polymer burden drives ER stress, mitochondrial depolarization, caspase activation, and hepatocyte death.
hepatocyte CL:0000182 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves hepatocyte (CL:0000182). CL:0000182 is a cell type from the Cell Ontology.
autophagy GO:0006914 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves autophagy (GO:0006914). GO:0006914 is a biological process from the Gene Ontology.
Experimental models
CRISPR-engineered Huh7.5Z hepatocyte cell line CELL LINE The line reports UPR, caspase, apoptosis, chaperone, and autophagy responses.
Downstream
Hepatic Stellate Cell Activation Chronic hepatocyte death and compensatory regeneration activate hepatic stellate cells.
Neonatal Cholestasis A small portion of affected children develop AATD-associated neonatal cholestasis.
Hepatocellular Carcinoma Hepatocellular carcinoma can occur in AATD-associated end-stage liver disease.
Show evidence (1 reference)
PMID:28752441 SUPPORT Other
"This intracellular death cascade appears to involve ER stress, mitochondrial depolarization, and caspase cleavage, and is possibly linked to autophagy and redox injury."
Mechanistic review identifies ER stress, mitochondrial depolarization, and caspase activation as the death cascade triggered by Z-AAT polymers.
Hepatic Stellate Cell Activation
Recurrent hepatocyte death and compensatory regeneration activate hepatic stellate cells, initiating the fibrotic response.
hepatic stellate cell CL:0000632 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves hepatic stellate cell (CL:0000632). CL:0000632 is a cell type from the Cell Ontology.
collagen fibril organization GO:0030199 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased collagen fibril organization (GO:0030199). GO:0030199 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Hepatic Fibrosis Stellate cell activation and collagen deposition produce hepatic fibrosis.
Liver Cirrhosis Progressive bridging fibrosis produces cirrhosis.
Show evidence (1 reference)
PMID:28752441 SUPPORT Other
"This chronic cycle of cell death and regeneration activates hepatic stellate cells and initiates the process of hepatic fibrosis."
The review directly supports stellate-cell activation as the start of hepatic fibrosis.
Alveolar Tissue Destruction
Progressive degradation of alveolar walls and elastin fibers leads to loss of structural integrity, air trapping, and emphysema development.
extracellular matrix disassembly GO:0022617 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves extracellular matrix disassembly (GO:0022617). GO:0022617 is a biological process from the Gene Ontology.
Downstream
Emphysema Alveolar wall destruction produces the panacinar emphysema phenotype.
Chronic Obstructive Pulmonary Disease Progressive emphysematous tissue destruction produces chronic obstructive pulmonary disease.
Neutrophilic Subcutaneous Inflammation
AATD-associated panniculitis can show extensive subcutaneous inflammation with neutrophils, foamy macrophages, and fat necrosis.
neutrophil CL:0000775 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves neutrophil (CL:0000775). CL:0000775 is a cell type from the Cell Ontology.
Downstream
Panniculitis Neutrophilic inflammation and fat necrosis constitute the panniculitis lesion.
Show evidence (1 reference)
PMID:26527439 SUPPORT Human Clinical
"Biopsy specimens of the right upper limb revealed extensive panniculitis with neutrophils, foamy macrophages, and fat necrosis."
Human biopsy evidence defines the inflammatory cellular lesion without overclaiming its upstream molecular cause.
✶

Histopathology

1
PAS-Positive Diastase-Resistant Globules
PAS-positive, diastase-resistant globules are a liver-biopsy finding used in AATD diagnosis, and hepatic globule burden can be reduced by fazirsiran.
Show evidence (2 references)
PMID:26052388 SUPPORT Human Clinical
"A1ATD was diagnosed using phenotype characterization (MZ or ZZ), liver biopsy detection of PAS-positive diastase-resistant (PAS+) globules, or both."
Cleveland Clinic ESLD cohort treats PAS+ diastase-resistant globules as a diagnostic histopathologic finding for AATD on liver biopsy.
PMID:38964420 SUPPORT Human Clinical
"All fazirsiran-treated patients had histologic reduction from baseline in hepatic globule burden."
SEQUOIA Phase 2 trial confirms hepatic globules are quantifiable and pharmacodynamically modifiable, anchoring globule burden as a histopathologic biomarker.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Alpha-1 Antitrypsin Deficiency Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

9
Cardiovascular 1
Granulomatosis with Polyangiitis Vasculitis HP:0002633 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is granulomatosis with polyangiitis, annotated with Vasculitis (HP:0002633). HP:0002633 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:20301692 SUPPORT Other
"Individuals with AATD are also at increased risk for panniculitis (migratory, inflammatory, tender skin nodules which may ulcerate on legs and lower abdomen) and C-ANCA-positive vasculitis (granulomatosis with polyangiitis)."
GeneReviews directly identifies C-ANCA-positive granulomatosis with polyangiitis in the AATD phenotype spectrum.
Digestive 4
Liver Cirrhosis HP:0001394 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is cirrhosis (HP:0001394), qualified as course progressive. HP:0001394 is a phenotype from the Human Phenotype Ontology.
Course: PROGRESSIVE
Show evidence (2 references)
PMID:35868681 SUPPORT Other
"Liver disease in homozygous ZZ alpha-1 antitrypsin (AAT) deficiency occurs due to the accumulation of large quantities of AAT mutant Z protein polymers in the liver."
Confirms that homozygous ZZ genotype leads to hepatocytic protein accumulation and liver disease
PMID:32376409 SUPPORT Human Clinical
"AAT inclusions were detected in liver biopsies of 63% of subjects with the Pi∗MZ genotype, vs 97% of subjects with the Pi∗ZZ genotype, and increased with liver fibrosis stages."
European Alpha-1 Liver Cohort biopsy data confirm Z-AAT inclusions are near-universal in PiZZ adults and correlate with fibrosis stage.
Hepatic Fibrosis HP:0001395 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is hepatic fibrosis (HP:0001395), qualified as course progressive. HP:0001395 is a phenotype from the Human Phenotype Ontology.
Course: PROGRESSIVE
Show evidence (1 reference)
PMID:32376409 SUPPORT Human Clinical
"Ten percent of subjects with the Pi∗MZ genotype vs 4% of noncarriers had LSMs of 7.1 kPa or more (adjusted odds ratio, 4.8; 95% confidence interval, 2.0-11.8)."
Quantifies elevated liver stiffness as a fibrosis biomarker in heterozygous Pi*MZ adults.
Hepatocellular Carcinoma HP:0001402 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is hepatocellular carcinoma (HP:0001402). HP:0001402 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:26052388 SUPPORT Human Clinical
"In the A1ATD group, the incidence rate of HCC was 8.5% compared to 31% in the group of patients with other causes of cirrhosis (P = 0.001)."
Cleveland Clinic ESLD cohort quantifies HCC incidence in AATD cirrhosis (8.5%), supporting HCC as a recognized but lower-frequency complication.
Neonatal Cholestasis HP:0001396 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is neonatal cholestasis, annotated with Cholestasis (HP:0001396). HP:0001396 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:20301692 SUPPORT Other
"AATD-associated liver disease, which is present in only a small portion of affected children, manifests as neonatal cholestasis."
GeneReviews directly supports neonatal cholestasis as the characteristic pediatric liver presentation.
Immune 1
Panniculitis HP:0012490 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is panniculitis (HP:0012490). HP:0012490 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:33516773 SUPPORT Other
"Panniculitis represents a rare and potentially lethal manifestation of alpha-1 antitrypsin deficiency (AATD)."
Establishes panniculitis as a rare but significant cutaneous manifestation of AAT deficiency
Respiratory 3
Emphysema Panacinar emphysema HP:0032967 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is panacinar emphysema (HP:0032967). HP:0032967 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:20301692 SUPPORT Other
"Alpha-1 antitrypsin deficiency (AATD) can present with hepatic dysfunction in individuals from infancy to adulthood and with chronic obstructive lung disease (emphysema and/or bronchiectasis), characteristically in individuals older than age 30 years."
Establishes emphysema as a cardinal manifestation of AATD occurring characteristically in adults over 30 years of age
PMID:35361631 SUPPORT Human Clinical
"Severe alpha-1-antitrypsin deficiency (AATD), phenotype PiZZ, is a risk factor for pulmonary emphysema and liver disease, but its effect on cancer risk is unknown."
Confirms that severe AATD (PiZZ phenotype) carries significant risk for emphysema development
Chronic Obstructive Pulmonary Disease Chronic pulmonary obstruction HP:0006510 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is chronic obstructive pulmonary disease, annotated with Chronic pulmonary obstruction (HP:0006510). HP:0006510 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:20301692 SUPPORT Other
"Alpha-1 antitrypsin deficiency (AATD) can present with hepatic dysfunction in individuals from infancy to adulthood and with chronic obstructive lung disease (emphysema and/or bronchiectasis), characteristically in individuals older than age 30 years."
GeneReviews directly supports chronic obstructive lung disease as the characteristic adult pulmonary presentation.
Bronchiectasis HP:0002110 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is bronchiectasis (HP:0002110). HP:0002110 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:20301692 SUPPORT Other
"Alpha-1 antitrypsin deficiency (AATD) can present with hepatic dysfunction in individuals from infancy to adulthood and with chronic obstructive lung disease (emphysema and/or bronchiectasis), characteristically in individuals older than age 30 years."
GeneReviews identifies bronchiectasis within the obstructive-lung presentation of AATD.
PMID:33192056 SUPPORT Human Clinical
"COPD/emphysema and bronchiectasis, but not asthma patients, exhibit higher frequency of AATD genotypes."
Large diagnostic-laboratory cohort directly supports bronchiectasis as part of the AATD lung phenotype spectrum, informing testing recommendations.
🧬

Genetic Associations

2
SERPINA1 (Causative)
Gene: SERPINA1 hgnc:8941 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is SERPINA1 (hgnc:8941). hgnc:8941 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: CAUSATIVE
Autosomal codominant inheritance
Show evidence (4 references)
PMID:38388492 SUPPORT Other
"Alpha 1 Antitrypsin Deficiency (AATD) is a largely underrecognized genetic condition characterized by low Alpha 1 Antitrypsin (AAT) serum levels, resulting from variations in SERPINA1."
Systematic literature review establishes SERPINA1 variation as the genetic cause of low circulating AAT.
PMID:38388492 SUPPORT Other
"The Z (c.1096G > A; p.Glu366Lys) and S (c.863A > T; p.Glu288Val) deficiency variants are the most frequently found variants in AATD, with the Z variant present in most individuals diagnosed with AATD."
Provides canonical nomenclature for the Z and S deficiency alleles and confirms Z as the most prevalent pathogenic variant.
PMID:37071847 SUPPORT Human Clinical
"Alpha-1 antitrypsin deficiency (AATD) is an underdiagnosed disorder associated with mutations in the SERPINA1 gene encoding alpha-1 antitrypsin (AAT)."
Confirms SERPINA1 as the disease gene and motivates expanded variant discovery beyond the canonical S/Z alleles.
+ 1 more reference
Somatic SERPINA1 escape variants in liver (Disease modifier)
Gene: SERPINA1 hgnc:8941 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is SERPINA1 (hgnc:8941). hgnc:8941 is a gene from the HUGO Gene Nomenclature Committee. relationship_type: MODIFIER
Show evidence (3 references)
PMID:40065168 SUPPORT Human Clinical
"We show that somatic variants in SERPINA1, the gene encoding A1AT, are strongly selected for in A1AT deficiency, with evidence of convergent evolution."
Nat Genet (2025) reports positive selection of somatic SERPINA1 variants in PiZZ liver, identifying a new tissue-level genetic phenomenon distinct from the germline disease.
PMID:40065168 SUPPORT Human Clinical
"Acquired SERPINA1 variants are clustered at the carboxyl terminus of A1AT, leading to truncation."
Localizes the somatic-escape variants to the C-terminus, mechanistically linking them to disrupted polymerization.
PMID:40065168 SUPPORT Other
"In vitro and in vivo, C-terminal truncation variants reduce disease-associated Z-A1AT polymer accumulation and disruption of the endoplasmic reticulum, supporting the C-terminal domain swap mechanism."
Functional experiments support reduced polymer accumulation and ER disruption from the selected truncations.
💊

Medical Actions

10
Alpha-1 Antitrypsin Augmentation Therapy
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Intravenous purified human plasma-derived AAT slows emphysema progression as measured by CT-density change.
Mechanism Target:
INHIBITS Protease-Antiprotease Imbalance in Lung — Restored circulating AAT suppresses the deficient-antiprotease state.
Target Phenotypes: panacinar emphysema HP:0032967 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets panacinar emphysema (HP:0032967). HP:0032967 is a phenotype from the Human Phenotype Ontology. panniculitis HP:0012490 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets panniculitis (HP:0012490). HP:0012490 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:22500781 SUPPORT Other
"Specific therapy for lung-affected individuals with AATD is augmentation therapy, which consists of intravenous infusion of purified human plasma-derived alpha-1 antitrypsin (AAT)."
This review describes augmentation therapy as the specific treatment for alpha-1 antitrypsin deficiency.
PMID:28496314 SUPPORT Other
"Meta-analyses were only possible for RCTs of intravenous augmentation, which slowed progression of emphysema measured by CT density change, 0.79 g/L/year versus placebo (P=0.002)"
The systematic review quantifies slower CT-density decline with intravenous augmentation.
Dapsone or Doxycycline for AATD-Associated Panniculitis
Action: pharmacotherapy for panniculitisNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is pharmacotherapy for panniculitis, annotated with Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. Ontology label: Pharmacotherapy NCIT:C15986
Agent: dapsone CHEBI:4325 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses dapsone (CHEBI:4325). CHEBI:4325 is a therapeutic agent from Chemical Entities of Biological Interest. doxycycline CHEBI:50845 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses doxycycline (CHEBI:50845). CHEBI:50845 is a therapeutic agent from Chemical Entities of Biological Interest.
GeneReviews identifies dapsone or doxycycline as therapy for panniculitis, with high-dose intravenous AAT augmentation for refractory disease.
Target Phenotypes: panniculitis HP:0012490 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets panniculitis (HP:0012490). HP:0012490 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:20301692 SUPPORT Other
"Dapsone or doxycycline therapy is used for panniculitis; if refractory to this, high-dose intravenous AAT augmentation therapy is indicated."
GeneReviews directly states the treatment sequence for AATD-associated panniculitis.
Alvelestat (Investigational Neutrophil Elastase Inhibitor)
Action: pharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. Ontology label: Pharmacotherapy NCIT:C15986
Alvelestat is an oral neutrophil-elastase inhibitor evaluated in two randomized Phase 2 AATD trials; 240 mg twice daily suppressed blood neutrophil elastase by more than 90% and reduced disease-activity biomarkers.
Mechanism Target:
INHIBITS Neutrophil Elastase Activity — Alvelestat directly inhibits neutrophil elastase and suppresses its measured activity.
Target Phenotypes: panacinar emphysema HP:0032967 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets panacinar emphysema (HP:0032967). HP:0032967 is a phenotype from the Human Phenotype Ontology.
Show evidence (3 references)
PMID:40967767 SUPPORT Human Clinical
"We conducted two complementary, double-blind, randomised, placebo-controlled, 12-week trials, incorporating two doses of alvelestat in AATD."
The publication reports the design of the two Phase 2 randomized trials.
PMID:40967767 SUPPORT Human Clinical
"Blood NE was significantly suppressed in both studies at both doses, with the greatest effect (>90% suppression) at alvelestat 240 mg twice daily."
The trials demonstrate dose-dependent target suppression at 240 mg twice daily.
PMID:40967767 SUPPORT Human Clinical
"There was no effect of alvelestat 120 mg on disease activity biomarkers, while 240 mg demonstrated significant reduction in Aα-Val360 and desmosine."
The biomarker result preserves the dose-specific efficacy limitation.
SAR447537 (INBRX-101; Investigational)
Action: pharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. Ontology label: Pharmacotherapy NCIT:C15986
SAR447537 (INBRX-101) was compared with plasma-derived A1PI therapy in a Phase 2 study of adults with AATD emphysema.
Target Phenotypes: emphysema HP:0002097 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets emphysema (HP:0002097). HP:0002097 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
clinicaltrials:NCT05856331 SUPPORT Human Clinical
"Phase 2 study to compare SAR447537 (INBRX-101) to plasma derived A1PI therapy in adults with AATD emphysema"
ClinicalTrials.gov directly supports the intervention, comparator, phase, and population.
Smoking Cessation
Smoking avoidance is a central modifiable measure because tobacco exposure increases emphysema risk in AATD.
Show evidence (1 reference)
PMID:35715315 SUPPORT Other
"Assessed by CO transfer alteration and CT scan, risk of pulmonary emphysema is increased by tobacco consumption."
Establishes smoking as a major modifiable risk factor that significantly increases emphysema risk in AAT deficiency
Avoidance of harmful inhalational exposures and excessive alcohol
GeneReviews recommends avoiding active and passive smoking, relevant occupational pollutants, and excessive alcohol use.
Show evidence (1 reference)
PMID:20301692 SUPPORT Other
"Agents/circumstances to avoid: Smoking (both active and passive); occupational exposure to environmental pollutants used in agriculture, mineral dust, gas, and fumes; excessive use of alcohol."
GeneReviews directly enumerates avoidable pulmonary and hepatic exposures.
Bronchodilators
Action: bronchodilator therapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is bronchodilator therapy, annotated with Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. Ontology label: Pharmacotherapy NCIT:C15986
Agent: bronchodilator NCIT:C319 NCI Thesaurus (NCIT) Relation: this treatment uses this therapeutic agent This treatment uses bronchodilator (NCIT:C319). NCIT:C319 is a therapeutic agent from the NCI Thesaurus.
Inhaled medication is used as part of guideline-based management of AATD-associated obstructive lung disease.
Target Phenotypes: chronic obstructive pulmonary disease HP:0006510 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets chronic obstructive pulmonary disease, annotated with Chronic pulmonary obstruction (HP:0006510). HP:0006510 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:34356027 SUPPORT Other
"Most important treatment is smoking cessation, pulmonary rehabilitation and inhaled medication according to current guidelines."
Confirms inhaled bronchodilators as part of standard treatment guidelines for AAT deficiency-related COPD
Lung Transplantation
Action: Lung TransplantationNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Lung Transplantation (NCIT:C15274). NCIT:C15274 is a clinical intervention from the NCI Thesaurus. NCIT:C15274
Lung transplantation may be considered for end-stage lung disease.
Mechanism Target:
BYPASSES Alveolar Tissue Destruction — Transplantation replaces end-stage structurally destroyed lung tissue.
Target Phenotypes: panacinar emphysema HP:0032967 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets panacinar emphysema (HP:0032967). HP:0032967 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:20301692 SUPPORT Other
"Lung transplantation may be an appropriate option for individuals with end-stage lung disease."
Establishes lung transplantation as appropriate therapeutic option for end-stage AAT deficiency-related emphysema
Fazirsiran (Investigational siRNA)
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: fazirsiran NCIT:C188640 NCI Thesaurus (NCIT) Relation: this treatment uses this therapeutic agent This treatment uses fazirsiran (NCIT:C188640). NCIT:C188640 is a therapeutic agent from the NCI Thesaurus.
The RNA-interference therapeutic fazirsiran degrades Z-AAT mRNA. In the Phase 2 SEQUOIA trial, it produced dose-dependent serum and liver Z-AAT reduction and reduced hepatic globule burden.
Mechanism Target:
INHIBITS Hepatic Protein Aggregation — SERPINA1 mRNA silencing reduces synthesis and hepatic accumulation of Z-AAT.
Show evidence (3 references)
PMID:38964420 SUPPORT Human Clinical
"We evaluated the safety and efficacy of an investigational RNA interference therapeutic, fazirsiran, that degrades Z-AAT messenger RNA, reducing deleterious protein synthesis."
The Phase 2 report states the RNA-interference mechanism.
PMID:38964420 SUPPORT Human Clinical
"Fazirsiran reduced serum and liver concentrations of Z-AAT in a dose-dependent manner and reduced hepatic globule burden."
SEQUOIA Phase 2 RCT establishes fazirsiran as a liver-targeted siRNA that addresses the gain-of-toxic-function arm of AATD by lowering hepatic Z-AAT.
PMID:38964420 SUPPORT Human Clinical
"All fazirsiran-treated patients had histologic reduction from baseline in hepatic globule burden."
Histologic endpoint confirms target engagement at the hepatocyte level, the proximal pathologic lesion of AATD liver disease.
Liver Transplantation
Action: transplantation procedureNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is transplantation procedure, annotated with Transplantation (NCIT:C15342). NCIT:C15342 is a clinical intervention from the NCI Thesaurus. Ontology label: Transplantation NCIT:C15342
Liver transplantation is the definitive treatment for severe AATD liver disease and restores circulating AAT levels.
Mechanism Target:
BYPASSES Hepatic Protein Aggregation — A donor liver replaces hepatocytes that synthesize and retain pathogenic Z-AAT.
Show evidence (4 references)
PMID:20301692 SUPPORT Other
"Liver transplantation is the definitive treatment for severe disease (will restore AAT levels)."
Establishes liver transplantation as definitive curative treatment that restores normal AAT production from donor liver
PMID:33824927 SUPPORT Other
"Rarely, patients require liver transplant and typically the patient outcomes are excellent."
Documents excellent outcomes in AAT deficiency patients undergoing liver transplantation
PMID:37144533 SUPPORT Other
"Pi∗ZZ individuals harbor an up to 20 times higher risk of liver fibrosis and cirrhosis than noncarriers and liver transplantation is currently the only available therapeutic option."
Confirms liver transplantation as essential therapeutic option for severe ZZ genotype liver disease
+ 1 more reference
🌍

Environmental Factors

2
Cigarette Smoking
exposure to cigarette smoking ECTO:0100003 Environmental Conditions, Treatments and Exposures Ontology (ECTO) Relation: this environmental factor is this exposure This environmental factor is exposure to cigarette smoking (ECTO:0100003). ECTO:0100003 is an exposure from the Environmental Conditions, Treatments and Exposures Ontology.
Cigarette smoking accelerates emphysema development and lung-function decline in AATD.
Show evidence (2 references)
PMID:39980299 SUPPORT Other
"The development of emphysema and decline in lung function varies by AATD genotype and is accelerated by risk factors, such as smoking."
2025 mechanistic review identifies smoking as a primary accelerator of AATD-related emphysema and lung function decline.
PMID:40943425 SUPPORT Other
"AATD and smoking represent major risk factors for COPD, the third leading cause of death worldwide at present."
2025 mechanistic review identifies smoking as a co-equal major risk factor for COPD alongside AATD genotype.
Mechanism Target:
EXACERBATES Alveolar Tissue Destruction — Emphysema is alveolar destruction, and the cited sentence names both the exposure and that outcome. Recorded as exacerbating rather than triggering because the destruction proceeds from the inherited antiprotease deficiency and smoking accelerates it, which is the word the source uses. The intervening step is the protease-antiprotease imbalance this entry models explicitly, so the intermediates are known rather than unknown.
Show evidence (2 references)
PMID:39980299 SUPPORT Other
"The development of emphysema and decline in lung function varies by AATD genotype and is accelerated by risk factors, such as smoking."
States that emphysema development and lung-function decline are accelerated by risk factors such as smoking, naming the exposure and the alveolar destruction at this node.
PMID:40943425 SUPPORT Other
"AATD and smoking represent major risk factors for COPD, the third leading cause of death worldwide at present."
Places the deficiency and smoking together as major risk factors for chronic obstructive lung disease. It sets the two side by side without saying what smoking does to this node.
Metabolic Cofactors
Obesity and diabetes are important cofactors associated with elevated liver stiffness in Pi*MZ adults.
Show evidence (1 reference)
PMID:32376409 SUPPORT Human Clinical
"Obesity and diabetes were the most important factors associated with LSMs ≥7.1 kPa in subjects with the Pi∗MZ genotype."
European Alpha-1 Liver Cohort identifies obesity and diabetes as the strongest measured correlates of elevated liver stiffness in Pi*MZ adults.
Mechanism Target:
EXACERBATES Hepatic Stellate Cell Activation — Obesity and diabetes are recorded here as accelerants of the hepatic arm rather than the pulmonary one. Two limits are worth stating rather than leaving in the grade: the measurement is liver stiffness, a proxy for the fibrosis this node drives rather than a measure of stellate cell activation, and the finding is specific to heterozygous Pi*MZ adults rather than to the classic homozygous disease this entry mostly models.
Show evidence (1 reference)
PMID:32376409 SUPPORT Human Clinical
"Obesity and diabetes were the most important factors associated with LSMs ≥7.1 kPa in subjects with the Pi∗MZ genotype."
Identifies obesity and diabetes as the strongest measured correlates of raised liver stiffness in Pi*MZ adults. A stiffness proxy in a heterozygous cohort, one step off this node in two directions at once.
🔬

Biochemical Markers

2
Serum Alpha-1 Antitrypsin Concentration (Decreased)
Context: Serum AAT below 57 mg/dL (~11 µM) defines severe deficiency and is the threshold used for augmentation-therapy eligibility in the cited guideline. Serum measurement is followed by phenotyping or genotyping.
Show evidence (1 reference)
PMID:39661838 SUPPORT Other
"Exogenous administration of purified human serum-derived AAT is the only specific treatment approved for AATD in nonsmoking patients with severe deficiency (serum AAT concentration of < 57 mg/dL or < 11 µM), with evidence of functional loss above the physiological level."
2024 Brazilian Thoracic Society guideline directly states the severe-deficiency threshold (<57 mg/dL or <11 µM) used for augmentation therapy eligibility.
Z-Alpha-1 Antitrypsin Polymer (Elevated in liver tissue)
Context: Hepatic AAT polymer load correlates with fibrosis stage and clinical outcome, and liver Z-AAT concentration is reduced by hepatocyte-targeted Z-AAT mRNA silencing with fazirsiran.
Show evidence (3 references)
PMID:32726073 SUPPORT Human Clinical
"The AAT polymer load correlated closely with hepatic fibrosis stage and long-term clinical outcome, independent of homozygous or heterozygous status."
Human liver-tissue analysis links polymer load to fibrosis stage and long-term outcome.
PMID:32376409 SUPPORT Human Clinical
"AAT inclusions were detected in liver biopsies of 63% of subjects with the Pi∗MZ genotype, vs 97% of subjects with the Pi∗ZZ genotype, and increased with liver fibrosis stages."
Biopsy-based quantification of Z-AAT inclusions confirms the polymer biomarker correlates with fibrosis stage in PiZZ adults and is detectable in many PiMZ heterozygotes.
PMID:38964420 SUPPORT Human Clinical
"At postdose liver biopsy, fazirsiran reduced median liver Z-AAT concentration by 93% compared with an increase of 26% with placebo."
Phase 2 SEQUOIA trial demonstrates that intrahepatic Z-AAT is pharmacodynamically modifiable, validating the biochemical biomarker.
🔬

Diagnosis

4
Serum alpha-1 antitrypsin measurement
Demonstration of a low serum AAT concentration is the biochemical component of AATD diagnosis.
alpha-1 antitrypsin measurement NCIT:C25294 NCI Thesaurus (NCIT)
Show evidence (1 reference)
PMID:20301692 SUPPORT Other
"The diagnosis of AATD relies on demonstration of low serum concentration of alpha-1 antitrypsin (AAT) and either identification of biallelic pathogenic variants in SERPINA1 or detection of a functionally deficient AAT protein variant by protease inhibitor (PI) typing."
GeneReviews identifies low serum AAT as the biochemical component of diagnosis.
Confirmatory PI typing or SERPINA1 genetic testing
A low serum AAT result is confirmed by either biallelic pathogenic SERPINA1 variants or a functionally deficient protein variant identified by protease-inhibitor typing.
genetic testing NCIT:C15709 NCI Thesaurus (NCIT)
Show evidence (1 reference)
PMID:20301692 SUPPORT Other
"The diagnosis of AATD relies on demonstration of low serum concentration of alpha-1 antitrypsin (AAT) and either identification of biallelic pathogenic variants in SERPINA1 or detection of a functionally deficient AAT protein variant by protease inhibitor (PI) typing."
GeneReviews directly states the biochemical-plus-genetic/protein diagnostic criteria.
Longitudinal pulmonary and hepatic surveillance
Surveillance includes pulmonary function testing and liver laboratory and imaging assessment every six to twelve months.
Show evidence (1 reference)
PMID:20301692 SUPPORT Other
"Every six to 12 months: pulmonary function tests including spirometry with bronchodilators and diffusing capacity measurements; liver function tests, platelet count and liver ultrasound, elastography (e.g., FibroScan), magnetic resonance imaging."
GeneReviews states the pulmonary and hepatic surveillance modalities and interval.
Evaluation and counseling of relatives at risk
Parents, siblings, and offspring of an individual with severe AATD should be evaluated so treatment and preventive measures can begin early when needed.
genetic counseling NCIT:C15240 NCI Thesaurus (NCIT)
Show evidence (2 references)
PMID:20301692 SUPPORT Other
"Evaluation of parents, older and younger sibs, and offspring of an individual with severe AATD in order to identify as early as possible those relatives who would benefit from institution of treatment and preventive measures."
GeneReviews directly supports cascade evaluation of first-degree relatives.
PMID:20301692 SUPPORT Other
"Heterozygote testing for at-risk family members and prenatal and preimplantation genetic testing are possible once the pathogenic SERPINA1 variants have been identified in the family."
GeneReviews states the available reproductive and heterozygote-testing options.
📊

Prevalence

3
Western Europe and the United States
Birth Prevalence 20.0–40.0 per 100,000 1–9 per 10,000
Severe alpha-1 antitrypsin deficiency is most prevalent in populations of European ancestry. Genotype-based estimates in Western Europe and the United States are around 1 in 2,500 to 1 in 5,000 newborns, while diagnosed prevalence in a large German claims database was lower at 23.73 per 100,000 overall, consistent with underrecognition.
Show evidence (2 references)
PMID:18565211 SUPPORT Other
"The prevalence in Western Europe and in the USA is estimated at approximately 1 in 2,500 and 1 : 5,000 newborns, and is highly dependent on the Scandinavian descent within the population."
Review-level epidemiology gives the standard severe-disease prevalence range for alpha-1 antitrypsin deficiency in high-prevalence populations.
PMID:27824593 SUPPORT Human Clinical
"corresponding to a prevalence of 23.73 per 100 000 in all age groups and 29.36 per 100 000 in those ≥30 years."
Population-based claims data show that diagnosed prevalence is substantially lower than genotype-based estimates, supporting under-ascertainment in routine care.
Worldwide diagnosed AATD population
AATD remains substantially underdiagnosed worldwide. A 2024 international guideline emphasizes that diagnosis is often delayed and that targeted/cascade testing in high-risk groups is the main case-finding strategy outside the few jurisdictions with newborn screening.
Show evidence (1 reference)
PMID:39661838 SUPPORT Other
"Unfortunately, underdiagnosis is quite common; it is possible that only 10% of cases are diagnosed."
2024 Brazilian Thoracic Society guideline quantifies AATD underdiagnosis at ~90% (only ~10% diagnosed), supporting prevalence underestimation.
AATD contribution to COPD/bronchiectasis
Among adults with COPD/emphysema or bronchiectasis, AATD genotypes (Pi*SZ and Pi*ZZ) are detected substantially more frequently than in asthma populations, supporting recommendations to test all adults with COPD or bronchiectasis.
Show evidence (1 reference)
PMID:33192056 SUPPORT Human Clinical
"COPD/emphysema and bronchiectasis, but not asthma patients, exhibit higher frequency of AATD genotypes."
Large German testing-laboratory cohort (29,465 kits) shows AATD genotype prevalence is enriched in both COPD and bronchiectasis populations, supporting case-finding policy.
🔀

Differential Diagnoses

1

Conditions with similar clinical presentations that must be differentiated from Alpha-1 Antitrypsin Deficiency:

📊

Related Datasets

2
The Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis Study (GRADS) Alpha-1 study [A1AT] geo:GSE109515
Whole genome mRNA and microRNA profiling of bronchoalveolar lavage (BAL) and peripheral blood mononuclear cell (PBMC) in Alpha-1 Antitrypsin Deficiency patients with PiZZ or PiMZ alpha-1 antitrypsin genotypes
human BULK RNA SEQ n=178
PMID:33303696
Identified by GEO DataSets index search for Alpha-1 Antitrypsin Deficiency (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
A Highly Phenotyped Open Access Repository of Alpha-1 Antitrypsin Deficiency Pluripotent Stem Cells geo:GSE140732
We profiled the global transcriptomes of 10 featured AATD-patient specific iPSC that underwent directed differentiation towards a hepatic and lung lineage. We used digital gene expression (DGE), a platform for high-fidelity RNA sequencing, and in addition to differentiated iPSC-derived cell types mentioned above (iHeps and iPSC-Lung progenitors), we also collected RNA from undifferentiated iPSCs and from a panel of primary adult human hepatocytes (PHH) for comparison.
human BULK RNA SEQ n=96
PMID:32619491
Identified by GEO DataSets index search for Alpha-1 Antitrypsin Deficiency (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
🔬

Clinical Trials

3
NCT03945292 PHASE_II COMPLETED
SEQUOIA: Phase 2 randomized placebo-controlled trial of fazirsiran (TAK-999, ARO-AAT), an investigational subcutaneous siRNA targeting Z-AAT mRNA in hepatocytes, in adults with PiZZ AATD-associated liver disease. The study demonstrated dose-dependent reduction of serum and liver Z-AAT and histologic improvement in hepatic globule burden.
Target Phenotypes: hepatic fibrosis HP:0001395 Human Phenotype Ontology (HP) Relation: this clinical trial targets this phenotype This clinical trial targets hepatic fibrosis (HP:0001395). HP:0001395 is a phenotype from the Human Phenotype Ontology. cirrhosis HP:0001394 Human Phenotype Ontology (HP) Relation: this clinical trial targets this phenotype This clinical trial targets cirrhosis (HP:0001394). HP:0001394 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
clinicaltrials:NCT03945292 SUPPORT Human Clinical
"The purpose of AROAAT2001 (SEQUOIA) is to evaluate the safety, efficacy and tolerability of multiple doses of the investigational product, Fazirsiran Injection, administered subcutaneously to participants with alpha-1 antitrypsin deficiency (AATD)."
ClinicalTrials.gov record confirms the SEQUOIA trial design and population for the fazirsiran Phase 2 study.
PMID:38964420 SUPPORT Human Clinical
"We evaluated the safety and efficacy of an investigational RNA interference therapeutic, fazirsiran, that degrades Z-AAT messenger RNA, reducing deleterious protein synthesis."
Peer-reviewed publication of SEQUOIA describes mechanism and outcomes of the trial intervention.
NCT04180319 NOT_APPLICABLE UNKNOWN
EARCO is a pan-European observational registry intended to provide longitudinal real-world data on severe AATD.
Target Phenotypes: emphysema HP:0002097 Human Phenotype Ontology (HP) Relation: this clinical trial targets this phenotype This clinical trial targets emphysema (HP:0002097). HP:0002097 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
clinicaltrials:NCT04180319 SUPPORT Human Clinical
"The core project is the pan-European AATD Registry, a collaboration which will offer longitudinal real-world data for patients with AATD."
ClinicalTrials.gov describes the registry and its longitudinal real-world purpose.
NCT05856331 PHASE_II COMPLETED
ELEVAATE is a Phase 2 comparison of SAR447537 (INBRX-101) with plasma-derived A1PI therapy in adults with AATD emphysema.
Target Phenotypes: emphysema HP:0002097 Human Phenotype Ontology (HP) Relation: this clinical trial targets this phenotype This clinical trial targets emphysema (HP:0002097). HP:0002097 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
clinicaltrials:NCT05856331 SUPPORT Human Clinical
"Phase 2 study to compare SAR447537 (INBRX-101) to plasma derived A1PI therapy in adults with AATD emphysema"
ClinicalTrials.gov record confirms the ELEVAATE Phase 2 active-controlled trial of recombinant long-acting A1PI vs plasma-derived augmentation.
🧫

Experimental Models

1
CRISPR-engineered Huh7.5Z hepatocyte cell line CELL_LINE
The CRISPR-engineered Huh7.5Z line shows UPR activation, caspase and apoptosis-marker activation, chaperone induction, and autophagy markers in a human hepatocellular background.
PI*Z AAT compared with parental PI*MM AAT cells
Organism
human NCBITaxon:9606 NCBI Taxonomy (NCBITaxon) Relation: this experimental model is built in this organism This experimental model is built in human, annotated with Homo sapiens (NCBITaxon:9606). NCBITaxon:9606 is an organism from the NCBI Taxonomy.
Cell source
CRISPR/Cas9-engineered Huh7.5 human hepatocellular cell line
Culture
Two-dimensional hepatocellular cell culture
Publication
PMID:35621045
Pathograph links
Hepatic Protein Aggregation PI*Z AAT expression produces the hepatocellular proteostasis lesion.
ER Stress and Unfolded Protein Response The line directly reports UPR activation and chaperone induction.
Hepatocyte Injury The line reports UPR, caspase, apoptosis, chaperone, and autophagy responses.
Show evidence (1 reference)
PMID:35621045 SUPPORT In Vitro
"Robust activation of UPR was observed in Huh7.5Z cells compared to Huh7.5 cells. Activated caspase cascade and apoptosis markers, increased chaperones, and autophagy markers were also detected in Z hepatocytes."
The engineered human cell model directly recapitulates UPR and injury readouts.
🐁

Animal Models

1
Full-length human PI*Z AAT transgenic mouse Mus musculus
A full-length human PI*Z AAT transgenic mouse shows selective attenuation of unfolded-protein-response signaling branches.
Hepatic protein aggregation and selective unfolded-protein-response signaling
Species
Mus musculus
Genotype
Full-length human PI*Z AAT transgenic mouse
Genes
SERPINA1 hgnc:8941 HUGO Gene Nomenclature Committee (hgnc) Relation: this experimental model concerns this gene This experimental model concerns SERPINA1 (hgnc:8941). hgnc:8941 is a gene from the HUGO Gene Nomenclature Committee.
Show evidence (1 reference)
PMID:35621045 SUPPORT Model Organism
"Selective attenuation of UPR signaling branches was observed in PI*Z hAAT mice in which the protein kinase R-like ER kinase and inositol-requiring enzyme1α branches were suppressed while the activating transcription factor 6α branch remained active."
The mouse experiment supports selective UPR-branch attenuation in vivo.
{ }

Source YAML

click to show 
name: Alpha-1 Antitrypsin Deficiency
creation_date: '2026-01-09T07:11:54Z'
description: >-
  Alpha-1 antitrypsin deficiency is an autosomal codominant disorder caused by
  pathogenic variants in SERPINA1, which encodes the principal circulating
  inhibitor of neutrophil elastase. The common severe Z allele causes the mutant
  protein to misfold and polymerize within hepatocytes, producing both a loss of
  circulating antiprotease activity and a toxic gain-of-function from hepatic
  polymer accumulation. Inadequate antiprotease protection lets neutrophil
  elastase degrade alveolar elastin, causing early-onset panacinar emphysema
  (accelerated by smoking), while the retained hepatic polymers can cause
  cirrhosis and hepatocellular carcinoma.
category: Mendelian
disease_term:
  preferred_term: alpha 1-antitrypsin deficiency
  term:
    id: MONDO:0013282
    label: alpha 1-antitrypsin deficiency
parents:
- Genetic Lung Diseases
- Hereditary Metabolic Diseases
classifications:
  harrisons_chapter:
  - classification_value: RESPIRATORY
    notes: >-
      Early-onset panacinar emphysema is the presenting and dominant clinical
      problem, so the respiratory Part is the primary chapter home.
  - classification_value: GASTROINTESTINAL
    notes: >-
      The hepatic arm - Z-AAT polymer retention causing cirrhosis and
      hepatocellular carcinoma - is a mechanistically distinct disease covered
      separately, so a second Part is assigned rather than folding it into the
      respiratory one.
  - classification_value: GENETICS_ENVIRONMENT_DISEASE
    notes: >-
      Mendelian SERPINA1 disorder with autosomal codominant expression, and the
      textbook gene-environment interaction: smoking sharply accelerates the
      emphysema arm.
  mechanistic_category:
  - classification_value: proteotoxic disease
    notes: >-
      The hepatic arm is a toxic gain-of-function from misfolded Z-AAT
      polymerizing and being retained in the hepatocyte endoplasmic reticulum -
      the archetypal serpinopathy. This is deliberately a claim about the liver
      disease only: the emphysema arm is a loss-of-function antiprotease
      deficiency, not a proteotoxic one, and the two arms of this disease have
      opposite mechanistic characters.
    evidence:
    - reference: PMID:35868681
      reference_title: "Alpha-1 Antitrypsin Deficiency Liver Disease."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Liver disease in homozygous ZZ alpha-1 antitrypsin (AAT) deficiency occurs due to the accumulation of large quantities of AAT mutant Z protein polymers in the liver."
      explanation: >-
        Attributes the liver disease to accumulation of mutant Z protein
        polymers, i.e. a proteotoxic rather than a loss-of-function mechanism.
inheritance:
- name: Autosomal codominant inheritance
  description: >-
    SERPINA1 alleles are expressed codominantly. When both parents carry one
    pathogenic allele, each sibling has a 25% chance of inheriting two
    pathogenic alleles, a 50% chance of being heterozygous, and a 25% chance of
    inheriting neither allele.
  inheritance_term:
    preferred_term: autosomal codominant inheritance
    term:
      id: HP:0032113
      label: Semidominant inheritance
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "AATD is inherited in an autosomal codominant manner."
    explanation: GeneReviews directly states the autosomal codominant inheritance pattern.
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "If both parents are heterozygous for one SERPINA1 pathogenic variant (e.g., PI*MZ), each sib of an affected individual has a 25% chance of being affected (PI*ZZ), a 50% chance of being heterozygous (PI*MZ), and a 25% chance of inheriting neither of the pathogenic variants (PI*MM)."
    explanation: GeneReviews gives the recurrence risks for two heterozygous parents.
prevalence:
- population: Western Europe and the United States
  measure_type: BIRTH_PREVALENCE
  prevalence_class: BAND_1_5_PER_10000
  rate_low: 20.0
  rate_high: 40.0
  percentage: 1 in 2,500-5,000
  notes: >-
    Severe alpha-1 antitrypsin deficiency is most prevalent in populations of
    European ancestry. Genotype-based estimates in Western Europe and the United
    States are around 1 in 2,500 to 1 in 5,000 newborns, while diagnosed
    prevalence in a large German claims database was lower at 23.73 per 100,000
    overall, consistent with underrecognition.
  evidence:
  - reference: PMID:18565211
    reference_title: Hereditary alpha-1-antitrypsin deficiency and its clinical consequences.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The prevalence in Western Europe and in the USA is estimated at approximately 1 in 2,500 and 1 : 5,000 newborns, and is highly dependent on the Scandinavian descent within the population."
    explanation: Review-level epidemiology gives the standard severe-disease prevalence range for alpha-1 antitrypsin deficiency in high-prevalence populations.
  - reference: PMID:27824593
    reference_title: 'The prevalence of diagnosed α1-antitrypsin deficiency and its comorbidities: results from a large population-based database.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "corresponding to a prevalence of 23.73 per 100 000 in all age groups and 29.36 per 100 000 in those ≥30 years."
    explanation: Population-based claims data show that diagnosed prevalence is substantially lower than genotype-based estimates, supporting under-ascertainment in routine care.
- population: Worldwide diagnosed AATD population
  notes: >-
    AATD remains substantially underdiagnosed worldwide. A 2024 international
    guideline emphasizes that diagnosis is often delayed and that targeted/cascade
    testing in high-risk groups is the main case-finding strategy outside the few
    jurisdictions with newborn screening.
  evidence:
  - reference: PMID:39661838
    reference_title: Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Unfortunately, underdiagnosis is quite common; it is possible that only 10% of cases are diagnosed."
    explanation: 2024 Brazilian Thoracic Society guideline quantifies AATD underdiagnosis at ~90% (only ~10% diagnosed), supporting prevalence underestimation.
- population: AATD contribution to COPD/bronchiectasis
  notes: >-
    Among adults with COPD/emphysema or bronchiectasis, AATD genotypes (Pi*SZ
    and Pi*ZZ) are detected substantially more frequently than in asthma
    populations, supporting recommendations to test all adults with COPD or
    bronchiectasis.
  evidence:
  - reference: PMID:33192056
    reference_title: The Distribution of Alpha-1 Antitrypsin Genotypes Between Patients with COPD/Emphysema, Asthma and Bronchiectasis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "COPD/emphysema and bronchiectasis, but not asthma patients, exhibit higher frequency of AATD genotypes."
    explanation: Large German testing-laboratory cohort (29,465 kits) shows AATD genotype prevalence is enriched in both COPD and bronchiectasis populations, supporting case-finding policy.
pathophysiology:
- name: Pulmonary Neutrophil Recruitment
  biological_scale: CELLULAR
  description: >-
    Pulmonary inflammatory stimuli recruit neutrophils from the circulation to
    affected tissue.
  cell_types:
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  biological_processes:
  - preferred_term: leukocyte migration
    term:
      id: GO:0050900
      label: leukocyte migration
  evidence:
  - reference: PMID:29258516
    reference_title: Neutrophil elastase in bronchiectasis.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Once inflammatory trigger develops in peripheral tissues, neutrophils are rapidly recruited toward to the anatomical site of inflammation."
    explanation: The respiratory review directly describes recruitment to inflamed tissue.
  downstream:
  - target: Pulmonary Neutrophil Degranulation
    description: Recruited neutrophils activate and degranulate in inflamed pulmonary tissue.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
- name: Pulmonary Neutrophil Degranulation
  biological_scale: CELLULAR
  description: >-
    Activated neutrophils degranulate and release inflammatory proteases,
    including neutrophil elastase.
  cell_types:
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  biological_processes:
  - preferred_term: neutrophil degranulation
    term:
      id: GO:0043312
      label: neutrophil degranulation
  evidence:
  - reference: PMID:29258516
    reference_title: Neutrophil elastase in bronchiectasis.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Neutrophil degranulation is responsible for the release of several inflammatory mediators, such as neutrophil elastase, cathepsin G, and proteinase 3"
    explanation: The respiratory review directly identifies neutrophil elastase as a degranulation product.
  downstream:
  - target: Neutrophil Elastase Activity
    description: Degranulation releases neutrophil elastase into the extracellular compartment.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:29258516
      reference_title: Neutrophil elastase in bronchiectasis.
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Neutrophil degranulation is responsible for the release of several inflammatory mediators, such as neutrophil elastase, cathepsin G, and proteinase 3"
      explanation: The review directly links degranulation to neutrophil-elastase release.
- name: Neutrophil Elastase Activity
  biological_scale: MOLECULAR
  description: >-
    Neutrophil elastase is the effector protease left insufficiently inhibited
    when functional AAT is deficient.
  molecular_functions:
  - preferred_term: serine-type endopeptidase activity
    term:
      id: GO:0004252
      label: serine-type endopeptidase activity
    modifier: INCREASED
  evidence:
  - reference: PMID:40967767
    reference_title: Two randomised controlled phase 2 studies of the oral neutrophil elastase inhibitor alvelestat in alpha-1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Alvelestat is an oral inhibitor of neutrophil elastase (NE) in development as a novel approach to AATD therapy."
    explanation: The Phase 2 report identifies neutrophil elastase as a therapeutic effector target in AATD.
  downstream:
  - target: Protease-Antiprotease Imbalance in Lung
    description: Neutrophil-elastase activity becomes insufficiently opposed when functional AAT is deficient.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:40967767
      reference_title: Two randomised controlled phase 2 studies of the oral neutrophil elastase inhibitor alvelestat in alpha-1 antitrypsin deficiency.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder that causes emphysema from lack of the alpha-1 antitrypsin (AAT) serpin antiprotease, leading to protease-antiprotease imbalance."
      explanation: The Phase 2 report directly states the deficient-antiprotease imbalance.
- name: Protease-Antiprotease Imbalance in Lung
  conforms_to: "emphysema_protease_antiprotease_imbalance#Protease-Antiprotease Imbalance"
  biological_scale: MOLECULAR
  description: >
    Reduced functional AAT disrupts protease-antiprotease homeostasis and
    decreases neutrophil-elastase inhibition.
  genes:
  - preferred_term: SERPINA1
    term:
      id: hgnc:8941
      label: SERPINA1
  evidence:
  - reference: PMID:39980299
    reference_title: Advancing the understanding and treatment of lung pathologies associated with alpha 1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Reduced levels of functional AAT disrupt the protease-antiprotease homeostasis, leading to a loss of neutrophil elastase inhibition and the breakdown of elastin within the lung interstitium."
    explanation: The review directly supports the protease-antiprotease imbalance and its tissue consequence.
  molecular_functions:
  - preferred_term: serine-type endopeptidase inhibitor activity
    term:
      id: GO:0004867
      label: serine-type endopeptidase inhibitor activity
    modifier: DECREASED
  downstream:
  - target: Alveolar Tissue Destruction
    description: >
      Reduced functional AAT leaves neutrophil elastase insufficiently
      inhibited, disrupting protease-antiprotease homeostasis and promoting
      elastin breakdown in the lung interstitium.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:39980299
      reference_title: "Advancing the understanding and treatment of lung pathologies associated with alpha 1 antitrypsin deficiency."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: >
        Reduced levels of functional AAT disrupt the protease-antiprotease
        homeostasis, leading to a loss of neutrophil elastase inhibition and the
        breakdown of elastin within the lung interstitium.
      explanation: >
        This mechanistic review directly links functional AAT deficiency to
        lost neutrophil elastase inhibition and elastin breakdown in lung tissue.
  - target: Bronchiectasis
    description: >
      Protease-antiprotease imbalance in AATD contributes to chronic obstructive
      lung disease phenotypes that include bronchiectasis.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
- name: Hepatic Protein Aggregation
  conforms_to: "er_protein_storage_disease#Hepatic Protein Aggregation"
  biological_scale: MOLECULAR
  description: >
    In PiZZ individuals, mutant Z-AAT misfolds during biogenesis and approximately
    85% is retained within hepatocytes rather than secreted, producing hepatic
    accumulation and limiting access to the circulation.
  genes:
  - preferred_term: SERPINA1
    term:
      id: hgnc:8941
      label: SERPINA1
  evidence:
  - reference: PMID:28752441
    reference_title: Pathophysiology of Alpha-1 Antitrypsin Deficiency Liver Disease.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "These homozygous individuals synthesize large quantities of a1AT mutant Z protein in the liver, but the mutant protein folds improperly during biogenesis and approximately 85% of the molecules are retained within the hepatocytes rather than appropriately secreted."
    explanation: Teckman & Blomenkamp quantify hepatic Z-AAT retention (~85%) and link it directly to deficient circulating AAT, supporting the hepatic-aggregation pathway as the proximal cause of both liver and lung disease.
  - reference: PMID:39440224
    reference_title: Liver Characterization of a Cohort of Alpha-1 Antitrypsin Deficiency Patients with and without Lung Disease.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by the misfolding and accumulation of the mutant variant of alpha-1 antitrypsin (AAT) within hepatocytes, which limits its access to the circulation and exposes the lungs to protease-mediated tissue damage."
    explanation: 2024 hepatology characterization study confirms the misfolding/hepatocyte-accumulation model of AATD pathogenesis.
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  downstream:
  - target: ER Stress and Unfolded Protein Response
    description: >-
      Intracellular Z-AAT retention provokes hepatocyte proteostasis stress.
  - target: Neutrophilic Subcutaneous Inflammation
    description: >
      Severe AATD can also produce panniculitis through a cutaneous mechanism
      whose intermediates remain incompletely established.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
  - target: Granulomatosis with Polyangiitis
    description: AATD is associated with C-ANCA-positive granulomatosis with polyangiitis through unresolved intermediates.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:20301692
      reference_title: Alpha-1 Antitrypsin Deficiency.
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Individuals with AATD are also at increased risk for panniculitis (migratory, inflammatory, tender skin nodules which may ulcerate on legs and lower abdomen) and C-ANCA-positive vasculitis (granulomatosis with polyangiitis)."
      explanation: GeneReviews directly supports the AATD association while the edge retains unknown intermediates.
  - target: Protease-Antiprotease Imbalance in Lung
    description: >
      Hepatocyte retention of mutant AAT limits circulating functional AAT,
      leaving the lung exposed to protease-mediated tissue injury.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:39440224
      reference_title: "Liver Characterization of a Cohort of Alpha-1 Antitrypsin Deficiency Patients with and without Lung Disease."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >
        Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder
        characterized by the misfolding and accumulation of the mutant variant
        of alpha-1 antitrypsin (AAT) within hepatocytes, which limits its access
        to the circulation and exposes the lungs to protease-mediated tissue
        damage.
      explanation: >
        Human AATD liver characterization links hepatocyte mutant AAT
        accumulation to reduced circulating access and downstream lung
        protease-mediated tissue damage.
- name: ER Stress and Unfolded Protein Response
  conforms_to: "er_protein_storage_disease#ER Stress and Unfolded Protein Response"
  biological_scale: CELLULAR
  description: >-
    Intracellular mutant Z-AAT initiates an ER-stress-associated hepatocyte
    injury cascade involving unfolded-protein-response signaling.
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  biological_processes:
  - preferred_term: response to endoplasmic reticulum stress
    term:
      id: GO:0034976
      label: response to endoplasmic reticulum stress
  - preferred_term: endoplasmic reticulum unfolded protein response
    term:
      id: GO:0030968
      label: endoplasmic reticulum unfolded protein response
  evidence:
  - reference: PMID:28752441
    reference_title: Pathophysiology of Alpha-1 Antitrypsin Deficiency Liver Disease.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "This intracellular death cascade appears to involve ER stress, mitochondrial depolarization, and caspase cleavage, and is possibly linked to autophagy and redox injury."
    explanation: The mechanistic review places ER stress within the intracellular hepatocyte injury cascade.
  downstream:
  - target: Hepatocyte Injury
    description: ER-stress-associated signaling proceeds to mitochondrial and caspase-linked hepatocyte injury.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:28752441
      reference_title: Pathophysiology of Alpha-1 Antitrypsin Deficiency Liver Disease.
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "This intracellular death cascade appears to involve ER stress, mitochondrial depolarization, and caspase cleavage, and is possibly linked to autophagy and redox injury."
      explanation: The review links ER stress with mitochondrial and caspase components of hepatocyte injury.
- name: Hepatocyte Injury
  biological_scale: CELLULAR
  description: >
    Chronic intracellular Z-AAT polymer burden drives ER stress, mitochondrial
    depolarization, caspase activation, and hepatocyte death.
  cell_types:
  - preferred_term: hepatocyte
    term:
      id: CL:0000182
      label: hepatocyte
  biological_processes:
  - preferred_term: autophagy
    term:
      id: GO:0006914
      label: autophagy
  evidence:
  - reference: PMID:28752441
    reference_title: Pathophysiology of Alpha-1 Antitrypsin Deficiency Liver Disease.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "This intracellular death cascade appears to involve ER stress, mitochondrial depolarization, and caspase cleavage, and is possibly linked to autophagy and redox injury."
    explanation: Mechanistic review identifies ER stress, mitochondrial depolarization, and caspase activation as the death cascade triggered by Z-AAT polymers.
  downstream:
  - target: Hepatic Stellate Cell Activation
    description: Chronic hepatocyte death and compensatory regeneration activate hepatic stellate cells.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:28752441
      reference_title: Pathophysiology of Alpha-1 Antitrypsin Deficiency Liver Disease.
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "This chronic cycle of cell death and regeneration activates hepatic stellate cells and initiates the process of hepatic fibrosis."
      explanation: The review links chronic hepatocyte death and regeneration to stellate-cell activation.
  - target: Neonatal Cholestasis
    description: A small portion of affected children develop AATD-associated neonatal cholestasis.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
  - target: Hepatocellular Carcinoma
    description: Hepatocellular carcinoma can occur in AATD-associated end-stage liver disease.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
- name: Hepatic Stellate Cell Activation
  biological_scale: CELLULAR
  conforms_to: "fibrotic_response#Mesenchymal Cell Activation"
  description: >-
    Recurrent hepatocyte death and compensatory regeneration activate hepatic
    stellate cells, initiating the fibrotic response.
  cell_types:
  - preferred_term: hepatic stellate cell
    term:
      id: CL:0000632
      label: hepatic stellate cell
  biological_processes:
  - preferred_term: collagen fibril organization
    term:
      id: GO:0030199
      label: collagen fibril organization
    modifier: INCREASED
  evidence:
  - reference: PMID:28752441
    reference_title: Pathophysiology of Alpha-1 Antitrypsin Deficiency Liver Disease.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "This chronic cycle of cell death and regeneration activates hepatic stellate cells and initiates the process of hepatic fibrosis."
    explanation: The review directly supports stellate-cell activation as the start of hepatic fibrosis.
  downstream:
  - target: Hepatic Fibrosis
    description: Stellate cell activation and collagen deposition produce hepatic fibrosis.
    causal_link_type: DIRECT
  - target: Liver Cirrhosis
    description: Progressive bridging fibrosis produces cirrhosis.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
- name: Alveolar Tissue Destruction
  biological_scale: TISSUE
  description: >
    Progressive degradation of alveolar walls and elastin fibers leads
    to loss of structural integrity, air trapping, and emphysema development.
  biological_processes:
  - preferred_term: extracellular matrix disassembly
    term:
      id: GO:0022617
      label: extracellular matrix disassembly
  downstream:
  - target: Emphysema
    description: Alveolar wall destruction produces the panacinar emphysema phenotype.
    causal_link_type: DIRECT
  - target: Chronic Obstructive Pulmonary Disease
    description: Progressive emphysematous tissue destruction produces chronic obstructive pulmonary disease.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
- name: Neutrophilic Subcutaneous Inflammation
  biological_scale: TISSUE
  description: >
    AATD-associated panniculitis can show extensive subcutaneous inflammation
    with neutrophils, foamy macrophages, and fat necrosis.
  cell_types:
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  downstream:
  - target: Panniculitis
    description: Neutrophilic inflammation and fat necrosis constitute the panniculitis lesion.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:26527439
      reference_title: "Unusual Acute Sequelae of α1-Antitrypsin Deficiency: A Myriad of Symptoms With One Common Cure."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Biopsy specimens of the right upper limb revealed extensive panniculitis with neutrophils, foamy macrophages, and fat necrosis."
      explanation: Human biopsy evidence links the inflammatory lesion to panniculitis.
  evidence:
  - reference: PMID:26527439
    reference_title: "Unusual Acute Sequelae of α1-Antitrypsin Deficiency: A Myriad of Symptoms With One Common Cure."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Biopsy specimens of the right upper limb revealed extensive panniculitis with neutrophils, foamy macrophages, and fat necrosis."
    explanation: Human biopsy evidence defines the inflammatory cellular lesion without overclaiming its upstream molecular cause.
phenotypes:
- name: Emphysema
  description: >
    Progressive destruction of alveolar tissue producing panacinar emphysema,
    typically as chronic obstructive lung disease after age 30 years.
  evidence:
  - reference: PMID:20301692
    reference_title: "Alpha-1 Antitrypsin Deficiency."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Alpha-1 antitrypsin deficiency (AATD) can present with hepatic dysfunction in individuals from infancy to adulthood and with chronic obstructive lung disease (emphysema and/or bronchiectasis), characteristically in individuals older than age 30 years."
    explanation: "Establishes emphysema as a cardinal manifestation of AATD occurring characteristically in adults over 30 years of age"
  - reference: PMID:35361631
    reference_title: "Cancer risk in severe alpha-1-antitrypsin deficiency."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Severe alpha-1-antitrypsin deficiency (AATD), phenotype PiZZ, is a risk factor for pulmonary emphysema and liver disease, but its effect on cancer risk is unknown."
    explanation: "Confirms that severe AATD (PiZZ phenotype) carries significant risk for emphysema development"
  phenotype_term:
    preferred_term: panacinar emphysema
    term:
      id: HP:0032967
      label: Panacinar emphysema
- name: Chronic Obstructive Pulmonary Disease
  description: >
    AATD can present as chronic obstructive lung disease, characteristically
    after age 30 years.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Alpha-1 antitrypsin deficiency (AATD) can present with hepatic dysfunction in individuals from infancy to adulthood and with chronic obstructive lung disease (emphysema and/or bronchiectasis), characteristically in individuals older than age 30 years."
    explanation: GeneReviews directly supports chronic obstructive lung disease as the characteristic adult pulmonary presentation.
  phenotype_term:
    preferred_term: chronic obstructive pulmonary disease
    term:
      id: HP:0006510
      label: Chronic pulmonary obstruction
- name: Liver Cirrhosis
  description: >
    Progressive liver fibrosis and cirrhosis resulting from accumulation of abnormal
    AAT polymers in hepatocytes. More common in ZZ homozygotes.
  evidence:
  - reference: PMID:35868681
    reference_title: "Alpha-1 Antitrypsin Deficiency Liver Disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Liver disease in homozygous ZZ alpha-1 antitrypsin (AAT) deficiency occurs due to the accumulation of large quantities of AAT mutant Z protein polymers in the liver."
    explanation: "Confirms that homozygous ZZ genotype leads to hepatocytic protein accumulation and liver disease"
  - reference: PMID:32376409
    reference_title: Liver Phenotypes of European Adults Heterozygous or Homozygous for Pi∗Z Variant of AAT (Pi∗MZ vs Pi∗ZZ genotype) and Noncarriers.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "AAT inclusions were detected in liver biopsies of 63% of subjects with the Pi∗MZ genotype, vs 97% of subjects with the Pi∗ZZ genotype, and increased with liver fibrosis stages."
    explanation: European Alpha-1 Liver Cohort biopsy data confirm Z-AAT inclusions are near-universal in PiZZ adults and correlate with fibrosis stage.
  phenotype_term:
    preferred_term: cirrhosis
    term:
      id: HP:0001394
      label: Cirrhosis
    clinical_course: PROGRESSIVE
- name: Hepatic Fibrosis
  description: >
    In a European cohort, Pi*MZ adults were more likely than noncarriers to have
    liver stiffness of at least 7.1 kPa.
  evidence:
  - reference: PMID:32376409
    reference_title: Liver Phenotypes of European Adults Heterozygous or Homozygous for Pi∗Z Variant of AAT (Pi∗MZ vs Pi∗ZZ genotype) and Noncarriers.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Ten percent of subjects with the Pi∗MZ genotype vs 4% of noncarriers had LSMs of 7.1 kPa or more (adjusted odds ratio, 4.8; 95% confidence interval, 2.0-11.8)."
    explanation: Quantifies elevated liver stiffness as a fibrosis biomarker in heterozygous Pi*MZ adults.
  phenotype_term:
    preferred_term: hepatic fibrosis
    term:
      id: HP:0001395
      label: Hepatic fibrosis
    clinical_course: PROGRESSIVE
- name: Hepatocellular Carcinoma
  description: >
    Hepatocellular carcinoma occurred in 8.5% of one AATD end-stage-liver-disease
    cohort, lower than in the comparator group with other causes of cirrhosis.
  evidence:
  - reference: PMID:26052388
    reference_title: Alpha-1 antitrypsin deficiency and the risk of hepatocellular carcinoma in end-stage liver disease.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In the A1ATD group, the incidence rate of HCC was 8.5% compared to 31% in the group of patients with other causes of cirrhosis (P = 0.001)."
    explanation: Cleveland Clinic ESLD cohort quantifies HCC incidence in AATD cirrhosis (8.5%), supporting HCC as a recognized but lower-frequency complication.
  phenotype_term:
    preferred_term: hepatocellular carcinoma
    term:
      id: HP:0001402
      label: Hepatocellular carcinoma
- name: Bronchiectasis
  description: >
    Bronchiectasis is a recognized obstructive-lung presentation of AATD, and
    AATD genotypes are enriched among patients tested for bronchiectasis.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Alpha-1 antitrypsin deficiency (AATD) can present with hepatic dysfunction in individuals from infancy to adulthood and with chronic obstructive lung disease (emphysema and/or bronchiectasis), characteristically in individuals older than age 30 years."
    explanation: GeneReviews identifies bronchiectasis within the obstructive-lung presentation of AATD.
  - reference: PMID:33192056
    reference_title: The Distribution of Alpha-1 Antitrypsin Genotypes Between Patients with COPD/Emphysema, Asthma and Bronchiectasis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "COPD/emphysema and bronchiectasis, but not asthma patients, exhibit higher frequency of AATD genotypes."
    explanation: Large diagnostic-laboratory cohort directly supports bronchiectasis as part of the AATD lung phenotype spectrum, informing testing recommendations.
  phenotype_term:
    preferred_term: bronchiectasis
    term:
      id: HP:0002110
      label: Bronchiectasis
- name: Neonatal Cholestasis
  description: >
    AATD-associated liver disease in a small portion of affected children
    presents as neonatal cholestasis.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "AATD-associated liver disease, which is present in only a small portion of affected children, manifests as neonatal cholestasis."
    explanation: GeneReviews directly supports neonatal cholestasis as the characteristic pediatric liver presentation.
  phenotype_term:
    preferred_term: neonatal cholestasis
    term:
      id: HP:0001396
      label: Cholestasis
- name: Panniculitis
  category: Cutaneous
  description: >
    Panniculitis is a rare and potentially lethal cutaneous manifestation of AATD.
  evidence:
  - reference: PMID:33516773
    reference_title: "Alpha-1 antitrypsin deficiency-associated panniculitis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Panniculitis represents a rare and potentially lethal manifestation of alpha-1 antitrypsin deficiency (AATD)."
    explanation: "Establishes panniculitis as a rare but significant cutaneous manifestation of AAT deficiency"
  phenotype_term:
    preferred_term: panniculitis
    term:
      id: HP:0012490
      label: Panniculitis
- name: Granulomatosis with Polyangiitis
  category: Vascular and immune
  description: >-
    AATD is associated with C-ANCA-positive vasculitis, including granulomatosis
    with polyangiitis.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Individuals with AATD are also at increased risk for panniculitis (migratory, inflammatory, tender skin nodules which may ulcerate on legs and lower abdomen) and C-ANCA-positive vasculitis (granulomatosis with polyangiitis)."
    explanation: GeneReviews directly identifies C-ANCA-positive granulomatosis with polyangiitis in the AATD phenotype spectrum.
  phenotype_term:
    preferred_term: granulomatosis with polyangiitis
    term:
      id: HP:0002633
      label: Vasculitis
treatments:
- name: Alpha-1 Antitrypsin Augmentation Therapy
  description: >
    Intravenous purified human plasma-derived AAT slows emphysema progression as
    measured by CT-density change.
  evidence:
  - reference: PMID:22500781
    reference_title: "A review of augmentation therapy for alpha-1 antitrypsin deficiency."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Specific therapy for lung-affected individuals with AATD is augmentation therapy, which consists of intravenous infusion of purified human plasma-derived alpha-1 antitrypsin (AAT)."
    explanation: "This review describes augmentation therapy as the specific treatment for alpha-1 antitrypsin deficiency."
  - reference: PMID:28496314
    reference_title: "Treatment of lung disease in alpha-1 antitrypsin deficiency: a systematic review."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Meta-analyses were only possible for RCTs of intravenous augmentation, which slowed progression of emphysema measured by CT density change, 0.79 g/L/year versus placebo (P=0.002)"
    explanation: The systematic review quantifies slower CT-density decline with intravenous augmentation.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  target_phenotypes:
  - preferred_term: panacinar emphysema
    term:
      id: HP:0032967
      label: Panacinar emphysema
  - preferred_term: panniculitis
    term:
      id: HP:0012490
      label: Panniculitis
  target_mechanisms:
  - target: Protease-Antiprotease Imbalance in Lung
    treatment_effect: INHIBITS
    description: Restored circulating AAT suppresses the deficient-antiprotease state.
- name: Dapsone or Doxycycline for AATD-Associated Panniculitis
  description: >-
    GeneReviews identifies dapsone or doxycycline as therapy for panniculitis,
    with high-dose intravenous AAT augmentation for refractory disease.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Dapsone or doxycycline therapy is used for panniculitis; if refractory to this, high-dose intravenous AAT augmentation therapy is indicated."
    explanation: GeneReviews directly states the treatment sequence for AATD-associated panniculitis.
  treatment_term:
    preferred_term: pharmacotherapy for panniculitis
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: dapsone
      term:
        id: CHEBI:4325
        label: dapsone
    - preferred_term: doxycycline
      term:
        id: CHEBI:50845
        label: doxycycline
  target_phenotypes:
  - preferred_term: panniculitis
    term:
      id: HP:0012490
      label: Panniculitis
- name: Alvelestat (Investigational Neutrophil Elastase Inhibitor)
  description: >-
    Alvelestat is an oral neutrophil-elastase inhibitor evaluated in two
    randomized Phase 2 AATD trials; 240 mg twice daily suppressed blood
    neutrophil elastase by more than 90% and reduced disease-activity biomarkers.
  evidence:
  - reference: PMID:40967767
    reference_title: Two randomised controlled phase 2 studies of the oral neutrophil elastase inhibitor alvelestat in alpha-1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We conducted two complementary, double-blind, randomised, placebo-controlled, 12-week trials, incorporating two doses of alvelestat in AATD."
    explanation: The publication reports the design of the two Phase 2 randomized trials.
  - reference: PMID:40967767
    reference_title: Two randomised controlled phase 2 studies of the oral neutrophil elastase inhibitor alvelestat in alpha-1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Blood NE was significantly suppressed in both studies at both doses, with the greatest effect (>90% suppression) at alvelestat 240 mg twice daily."
    explanation: The trials demonstrate dose-dependent target suppression at 240 mg twice daily.
  - reference: PMID:40967767
    reference_title: Two randomised controlled phase 2 studies of the oral neutrophil elastase inhibitor alvelestat in alpha-1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "There was no effect of alvelestat 120 mg on disease activity biomarkers, while 240 mg demonstrated significant reduction in Aα-Val360 and desmosine."
    explanation: The biomarker result preserves the dose-specific efficacy limitation.
  treatment_term:
    preferred_term: pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  target_phenotypes:
  - preferred_term: panacinar emphysema
    term:
      id: HP:0032967
      label: Panacinar emphysema
  target_mechanisms:
  - target: Neutrophil Elastase Activity
    treatment_effect: INHIBITS
    description: Alvelestat directly inhibits neutrophil elastase and suppresses its measured activity.
- name: SAR447537 (INBRX-101; Investigational)
  description: >-
    SAR447537 (INBRX-101) was compared with plasma-derived A1PI therapy in a
    Phase 2 study of adults with AATD emphysema.
  evidence:
  - reference: clinicaltrials:NCT05856331
    reference_title: Phase 2, Double-Blind, Randomized, Active-Control, Parallel Group Study to Assess the Pharmacokinetics, Pharmacodynamics, Immunogenicity, and Safety of SAR447537 (INBRX-101) Compared to Plasma-Derived Alpha1-Proteinase Inhibitor (A1PI) Augmentation Therapy in Adults With Alpha-1 Antitrypsin Deficiency (AATD) Emphysema
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Phase 2 study to compare SAR447537 (INBRX-101) to plasma derived A1PI therapy in adults with AATD emphysema"
    explanation: ClinicalTrials.gov directly supports the intervention, comparator, phase, and population.
  treatment_term:
    preferred_term: pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  target_phenotypes:
  - preferred_term: emphysema
    term:
      id: HP:0002097
      label: Emphysema
- name: Smoking Cessation
  description: >
    Smoking avoidance is a central modifiable measure because tobacco exposure
    increases emphysema risk in AATD.
  evidence:
  - reference: PMID:35715315
    reference_title: "[Alpha 1-antitrypsin deficiency]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Assessed by CO transfer alteration and CT scan, risk of pulmonary emphysema is increased by tobacco consumption."
    explanation: "Establishes smoking as a major modifiable risk factor that significantly increases emphysema risk in AAT deficiency"
- name: Avoidance of harmful inhalational exposures and excessive alcohol
  description: >-
    GeneReviews recommends avoiding active and passive smoking, relevant
    occupational pollutants, and excessive alcohol use.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Agents/circumstances to avoid: Smoking (both active and passive); occupational exposure to environmental pollutants used in agriculture, mineral dust, gas, and fumes; excessive use of alcohol."
    explanation: GeneReviews directly enumerates avoidable pulmonary and hepatic exposures.
- name: Bronchodilators
  description: >
    Inhaled medication is used as part of guideline-based management of
    AATD-associated obstructive lung disease.
  evidence:
  - reference: PMID:34356027
    reference_title: "[Alpha-1-antitrypsin deficiency]."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Most important treatment is smoking cessation, pulmonary rehabilitation and inhaled medication according to current guidelines."
    explanation: "Confirms inhaled bronchodilators as part of standard treatment guidelines for AAT deficiency-related COPD"
  treatment_term:
    preferred_term: bronchodilator therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: bronchodilator
      term:
        id: NCIT:C319
        label: Bronchodilator
  target_phenotypes:
  - preferred_term: chronic obstructive pulmonary disease
    term:
      id: HP:0006510
      label: Chronic pulmonary obstruction
- name: Lung Transplantation
  description: >
    Lung transplantation may be considered for end-stage lung disease.
  evidence:
  - reference: PMID:20301692
    reference_title: "Alpha-1 Antitrypsin Deficiency."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Lung transplantation may be an appropriate option for individuals with end-stage lung disease."
    explanation: "Establishes lung transplantation as appropriate therapeutic option for end-stage AAT deficiency-related emphysema"
  treatment_term:
    preferred_term: Lung Transplantation
    term:
      id: NCIT:C15274
      label: Lung Transplantation
  target_phenotypes:
  - preferred_term: panacinar emphysema
    term:
      id: HP:0032967
      label: Panacinar emphysema
  target_mechanisms:
  - target: Alveolar Tissue Destruction
    treatment_effect: BYPASSES
    description: Transplantation replaces end-stage structurally destroyed lung tissue.
- name: Fazirsiran (Investigational siRNA)
  description: >
    The RNA-interference therapeutic fazirsiran degrades Z-AAT mRNA. In the
    Phase 2 SEQUOIA trial, it produced dose-dependent serum and liver Z-AAT
    reduction and reduced hepatic globule burden.
  evidence:
  - reference: PMID:38964420
    reference_title: 'Fazirsiran for Adults With Alpha-1 Antitrypsin Deficiency Liver Disease: A Phase 2 Placebo Controlled Trial (SEQUOIA).'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We evaluated the safety and efficacy of an investigational RNA interference therapeutic, fazirsiran, that degrades Z-AAT messenger RNA, reducing deleterious protein synthesis."
    explanation: The Phase 2 report states the RNA-interference mechanism.
  - reference: PMID:38964420
    reference_title: 'Fazirsiran for Adults With Alpha-1 Antitrypsin Deficiency Liver Disease: A Phase 2 Placebo Controlled Trial (SEQUOIA).'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Fazirsiran reduced serum and liver concentrations of Z-AAT in a dose-dependent manner and reduced hepatic globule burden."
    explanation: SEQUOIA Phase 2 RCT establishes fazirsiran as a liver-targeted siRNA that addresses the gain-of-toxic-function arm of AATD by lowering hepatic Z-AAT.
  - reference: PMID:38964420
    reference_title: 'Fazirsiran for Adults With Alpha-1 Antitrypsin Deficiency Liver Disease: A Phase 2 Placebo Controlled Trial (SEQUOIA).'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All fazirsiran-treated patients had histologic reduction from baseline in hepatic globule burden."
    explanation: Histologic endpoint confirms target engagement at the hepatocyte level, the proximal pathologic lesion of AATD liver disease.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: fazirsiran
      term:
        id: NCIT:C188640
        label: Fazirsiran
  target_mechanisms:
  - target: Hepatic Protein Aggregation
    treatment_effect: INHIBITS
    description: SERPINA1 mRNA silencing reduces synthesis and hepatic accumulation of Z-AAT.
- name: Liver Transplantation
  description: >
    Liver transplantation is the definitive treatment for severe AATD liver
    disease and restores circulating AAT levels.
  evidence:
  - reference: PMID:20301692
    reference_title: "Alpha-1 Antitrypsin Deficiency."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Liver transplantation is the definitive treatment for severe disease (will restore AAT levels)."
    explanation: "Establishes liver transplantation as definitive curative treatment that restores normal AAT production from donor liver"
  - reference: PMID:33824927
    reference_title: "Alpha-1 antitrypsin deficiency liver disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Rarely, patients require liver transplant and typically the patient outcomes are excellent."
    explanation: "Documents excellent outcomes in AAT deficiency patients undergoing liver transplantation"
  - reference: PMID:37144533
    reference_title: "Cleaning up alpha-1 antitrypsin deficiency related liver disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Pi∗ZZ individuals harbor an up to 20 times higher risk of liver fibrosis and cirrhosis than noncarriers and liver transplantation is currently the only available therapeutic option."
    explanation: "Confirms liver transplantation as essential therapeutic option for severe ZZ genotype liver disease"
  - reference: PMID:36808684
    reference_title: "Liver transplantation for alpha 1 antitrypsin deficiency (A1ATD) using a heterozygous donor: Outcomes and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our case provides initial evidence that A1ATD heterozygote donors may be safely used for pediatric patients with A1ATD, thus expanding the donor pool."
    explanation: "Documents that heterozygous donors can be successfully used for AAT deficiency recipients, expanding available donor options"
  treatment_term:
    preferred_term: transplantation procedure
    term:
      id: NCIT:C15342
      label: Transplantation
  target_mechanisms:
  - target: Hepatic Protein Aggregation
    treatment_effect: BYPASSES
    description: A donor liver replaces hepatocytes that synthesize and retain pathogenic Z-AAT.
diagnosis:
- name: Serum alpha-1 antitrypsin measurement
  diagnosis_term:
    preferred_term: alpha-1 antitrypsin measurement
    term:
      id: NCIT:C25294
      label: Laboratory Procedure
  description: >-
    Demonstration of a low serum AAT concentration is the biochemical component
    of AATD diagnosis.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The diagnosis of AATD relies on demonstration of low serum concentration of alpha-1 antitrypsin (AAT) and either identification of biallelic pathogenic variants in SERPINA1 or detection of a functionally deficient AAT protein variant by protease inhibitor (PI) typing."
    explanation: GeneReviews identifies low serum AAT as the biochemical component of diagnosis.
- name: Confirmatory PI typing or SERPINA1 genetic testing
  diagnosis_term:
    preferred_term: genetic testing
    term:
      id: NCIT:C15709
      label: Genetic Testing
  description: >-
    A low serum AAT result is confirmed by either biallelic pathogenic SERPINA1
    variants or a functionally deficient protein variant identified by
    protease-inhibitor typing.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The diagnosis of AATD relies on demonstration of low serum concentration of alpha-1 antitrypsin (AAT) and either identification of biallelic pathogenic variants in SERPINA1 or detection of a functionally deficient AAT protein variant by protease inhibitor (PI) typing."
    explanation: GeneReviews directly states the biochemical-plus-genetic/protein diagnostic criteria.
- name: Longitudinal pulmonary and hepatic surveillance
  description: >-
    Surveillance includes pulmonary function testing and liver laboratory and
    imaging assessment every six to twelve months.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Every six to 12 months: pulmonary function tests including spirometry with bronchodilators and diffusing capacity measurements; liver function tests, platelet count and liver ultrasound, elastography (e.g., FibroScan), magnetic resonance imaging."
    explanation: GeneReviews states the pulmonary and hepatic surveillance modalities and interval.
- name: Evaluation and counseling of relatives at risk
  diagnosis_term:
    preferred_term: genetic counseling
    term:
      id: NCIT:C15240
      label: Genetic Counseling
  description: >-
    Parents, siblings, and offspring of an individual with severe AATD should be
    evaluated so treatment and preventive measures can begin early when needed.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Evaluation of parents, older and younger sibs, and offspring of an individual with severe AATD in order to identify as early as possible those relatives who would benefit from institution of treatment and preventive measures."
    explanation: GeneReviews directly supports cascade evaluation of first-degree relatives.
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Heterozygote testing for at-risk family members and prenatal and preimplantation genetic testing are possible once the pathogenic SERPINA1 variants have been identified in the family."
    explanation: GeneReviews states the available reproductive and heterozygote-testing options.
differential_diagnoses:
- name: Smoking-Related COPD
  disease_term:
    preferred_term: chronic obstructive pulmonary disease
    term:
      id: MONDO:0005002
      label: chronic obstructive pulmonary disease
  description: >-
    Smoking-related COPD overlaps with AATD-associated obstructive lung disease;
    serum AAT measurement followed by PI typing or SERPINA1 testing distinguishes
    AATD.
  distinguishing_features:
  - AATD obstructive lung disease characteristically includes emphysema and/or bronchiectasis after age 30 years.
  - Coexisting liver disease, panniculitis, or C-ANCA-positive granulomatosis with polyangiitis broadens suspicion beyond smoking-related COPD.
  - Low serum AAT plus deficient PI typing or biallelic pathogenic SERPINA1 variants supports AATD.
  evidence:
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Alpha-1 antitrypsin deficiency (AATD) can present with hepatic dysfunction in individuals from infancy to adulthood and with chronic obstructive lung disease (emphysema and/or bronchiectasis), characteristically in individuals older than age 30 years."
    explanation: GeneReviews supports the pulmonary onset pattern and coexisting liver manifestation used to raise suspicion for AATD.
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Individuals with AATD are also at increased risk for panniculitis (migratory, inflammatory, tender skin nodules which may ulcerate on legs and lower abdomen) and C-ANCA-positive vasculitis (granulomatosis with polyangiitis)."
    explanation: These extra-pulmonary manifestations help distinguish systemic AATD from isolated smoking-related COPD.
  - reference: PMID:20301692
    reference_title: Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The diagnosis of AATD relies on demonstration of low serum concentration of alpha-1 antitrypsin (AAT) and either identification of biallelic pathogenic variants in SERPINA1 or detection of a functionally deficient AAT protein variant by protease inhibitor (PI) typing."
    explanation: The AATD-specific biochemical and confirmatory tests distinguish it from non-AATD COPD.

genetic:
- name: SERPINA1
  association: Causative
  relationship_type: CAUSATIVE
  inheritance:
  - name: Autosomal codominant inheritance
  notes: >-
    SERPINA1 encodes alpha-1 antitrypsin. The common deficiency variants are Z
    (c.1096G>A; p.Glu366Lys in the cited nomenclature) and S (c.863A>T;
    p.Glu288Val); rarer pathogenic variants also occur.
  gene_term:
    preferred_term: SERPINA1
    term:
      id: hgnc:8941
      label: SERPINA1
  evidence:
  - reference: PMID:38388492
    reference_title: 'Rare variants in alpha 1 antitrypsin deficiency: a systematic literature review.'
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Alpha 1 Antitrypsin Deficiency (AATD) is a largely underrecognized genetic condition characterized by low Alpha 1 Antitrypsin (AAT) serum levels, resulting from variations in SERPINA1."
    explanation: Systematic literature review establishes SERPINA1 variation as the genetic cause of low circulating AAT.
  - reference: PMID:38388492
    reference_title: 'Rare variants in alpha 1 antitrypsin deficiency: a systematic literature review.'
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The Z (c.1096G > A; p.Glu366Lys) and S (c.863A > T; p.Glu288Val) deficiency variants are the most frequently found variants in AATD, with the Z variant present in most individuals diagnosed with AATD."
    explanation: Provides canonical nomenclature for the Z and S deficiency alleles and confirms Z as the most prevalent pathogenic variant.
  - reference: PMID:37071847
    reference_title: Comprehensive Clinical Diagnostic Pipelines Reveal New Variants in Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Alpha-1 antitrypsin deficiency (AATD) is an underdiagnosed disorder associated with mutations in the SERPINA1 gene encoding alpha-1 antitrypsin (AAT)."
    explanation: Confirms SERPINA1 as the disease gene and motivates expanded variant discovery beyond the canonical S/Z alleles.
  - reference: PMID:37071847
    reference_title: Comprehensive Clinical Diagnostic Pipelines Reveal New Variants in Alpha-1 Antitrypsin Deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Besides the most common pathogenic variants S (E264V) and Z (E342K), many rarer genetic variants of AAT have been found in patients and in the general population."
    explanation: Documents that pathogenic SERPINA1 variation extends well beyond the S/Z dyad, supporting comprehensive sequencing in atypical AATD presentations.
- name: Somatic SERPINA1 escape variants in liver
  association: Disease modifier
  relationship_type: MODIFIER
  notes: >-
    Liver hepatocytes from PiZZ adults accumulate clonal somatic SERPINA1
    truncating variants clustered at the carboxyl terminus of the protein.
    These C-terminal truncations confer a clonal selective advantage by
    reducing Z-AAT polymer accumulation and ER disruption, consistent with the
    C-terminal domain-swap polymerization model.
  gene_term:
    preferred_term: SERPINA1
    term:
      id: hgnc:8941
      label: SERPINA1
  evidence:
  - reference: PMID:40065168
    reference_title: Selection for somatic escape variants in SERPINA1 in the liver of patients with alpha-1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We show that somatic variants in SERPINA1, the gene encoding A1AT, are strongly selected for in A1AT deficiency, with evidence of convergent evolution."
    explanation: Nat Genet (2025) reports positive selection of somatic SERPINA1 variants in PiZZ liver, identifying a new tissue-level genetic phenomenon distinct from the germline disease.
  - reference: PMID:40065168
    reference_title: Selection for somatic escape variants in SERPINA1 in the liver of patients with alpha-1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acquired SERPINA1 variants are clustered at the carboxyl terminus of A1AT, leading to truncation."
    explanation: Localizes the somatic-escape variants to the C-terminus, mechanistically linking them to disrupted polymerization.
  - reference: PMID:40065168
    reference_title: Selection for somatic escape variants in SERPINA1 in the liver of patients with alpha-1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "In vitro and in vivo, C-terminal truncation variants reduce disease-associated Z-A1AT polymer accumulation and disruption of the endoplasmic reticulum, supporting the C-terminal domain swap mechanism."
    explanation: Functional experiments support reduced polymer accumulation and ER disruption from the selected truncations.

biochemical:
- name: Serum Alpha-1 Antitrypsin Concentration
  presence: Decreased
  context: >-
    Serum AAT below 57 mg/dL (~11 µM) defines severe deficiency and is the
    threshold used for augmentation-therapy eligibility in the cited guideline.
    Serum measurement is followed by phenotyping or genotyping.
  biomarker_term:
    preferred_term: alpha-1 antitrypsin
    term:
      id: NCIT:C105012
      label: Alpha-1-Antitrypsin
  evidence:
  - reference: PMID:39661838
    reference_title: Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Exogenous administration of purified human serum-derived AAT is the only specific treatment approved for AATD in nonsmoking patients with severe deficiency (serum AAT concentration of < 57 mg/dL or < 11 µM), with evidence of functional loss above the physiological level."
    explanation: 2024 Brazilian Thoracic Society guideline directly states the severe-deficiency threshold (<57 mg/dL or <11 µM) used for augmentation therapy eligibility.
- name: Z-Alpha-1 Antitrypsin Polymer
  presence: Elevated in liver tissue
  context: >-
    Hepatic AAT polymer load correlates with fibrosis stage and clinical outcome,
    and liver Z-AAT concentration is reduced by hepatocyte-targeted Z-AAT mRNA
    silencing with fazirsiran.
  evidence:
  - reference: PMID:32726073
    reference_title: The Alpha-1 Antitrypsin Polymer Load Correlates With Hepatocyte Senescence, Fibrosis Stage and Liver-Related Mortality.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The AAT polymer load correlated closely with hepatic fibrosis stage and long-term clinical outcome, independent of homozygous or heterozygous status."
    explanation: Human liver-tissue analysis links polymer load to fibrosis stage and long-term outcome.
  - reference: PMID:32376409
    reference_title: Liver Phenotypes of European Adults Heterozygous or Homozygous for Pi∗Z Variant of AAT (Pi∗MZ vs Pi∗ZZ genotype) and Noncarriers.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "AAT inclusions were detected in liver biopsies of 63% of subjects with the Pi∗MZ genotype, vs 97% of subjects with the Pi∗ZZ genotype, and increased with liver fibrosis stages."
    explanation: Biopsy-based quantification of Z-AAT inclusions confirms the polymer biomarker correlates with fibrosis stage in PiZZ adults and is detectable in many PiMZ heterozygotes.
  - reference: PMID:38964420
    reference_title: 'Fazirsiran for Adults With Alpha-1 Antitrypsin Deficiency Liver Disease: A Phase 2 Placebo Controlled Trial (SEQUOIA).'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "At postdose liver biopsy, fazirsiran reduced median liver Z-AAT concentration by 93% compared with an increase of 26% with placebo."
    explanation: Phase 2 SEQUOIA trial demonstrates that intrahepatic Z-AAT is pharmacodynamically modifiable, validating the biochemical biomarker.

environmental:
- name: Cigarette Smoking
  exposure_term:
    preferred_term: exposure to cigarette smoking
    term:
      id: ECTO:0100003
      label: exposure to cigarette smoking
  influences_mechanisms:
  - target: Alveolar Tissue Destruction
    environmental_effect: EXACERBATES
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      Emphysema is alveolar destruction, and the cited sentence names both the
      exposure and that outcome. Recorded as exacerbating rather than
      triggering because the destruction proceeds from the inherited
      antiprotease deficiency and smoking accelerates it, which is the word
      the source uses. The intervening step is the protease-antiprotease
      imbalance this entry models explicitly, so the intermediates are known
      rather than unknown.
    evidence:
    - reference: PMID:39980299
      reference_title: "Advancing the understanding and treatment of lung pathologies associated with alpha 1 antitrypsin deficiency."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "The development of emphysema and decline in lung function varies by AATD genotype and is accelerated by risk factors, such as smoking."
      explanation: >-
        States that emphysema development and lung-function decline are
        accelerated by risk factors such as smoking, naming the exposure and
        the alveolar destruction at this node.
    - reference: PMID:40943425
      reference_title: "Next-Generation Regenerative Therapies for Alpha-1 Antitrypsin Deficiency: Molecular Pathogenesis to Clinical Translation."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "AATD and smoking represent major risk factors for COPD, the third leading cause of death worldwide at present."
      explanation: >-
        Places the deficiency and smoking together as major risk factors for
        chronic obstructive lung disease. It sets the two side by side without
        saying what smoking does to this node.
  description: >-
    Cigarette smoking accelerates emphysema development and lung-function decline
    in AATD.
  effect: PROMOTES
  evidence:
  - reference: PMID:39980299
    reference_title: Advancing the understanding and treatment of lung pathologies associated with alpha 1 antitrypsin deficiency.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The development of emphysema and decline in lung function varies by AATD genotype and is accelerated by risk factors, such as smoking."
    explanation: 2025 mechanistic review identifies smoking as a primary accelerator of AATD-related emphysema and lung function decline.
  - reference: PMID:40943425
    reference_title: 'Next-Generation Regenerative Therapies for Alpha-1 Antitrypsin Deficiency: Molecular Pathogenesis to Clinical Translation.'
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "AATD and smoking represent major risk factors for COPD, the third leading cause of death worldwide at present."
    explanation: 2025 mechanistic review identifies smoking as a co-equal major risk factor for COPD alongside AATD genotype.
- name: Metabolic Cofactors
  influences_mechanisms:
  - target: Hepatic Stellate Cell Activation
    environmental_effect: EXACERBATES
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Obesity and diabetes are recorded here as accelerants of the hepatic arm
      rather than the pulmonary one. Two limits are worth stating rather than
      leaving in the grade: the measurement is liver stiffness, a proxy for
      the fibrosis this node drives rather than a measure of stellate cell
      activation, and the finding is specific to heterozygous Pi*MZ adults
      rather than to the classic homozygous disease this entry mostly models.
    evidence:
    - reference: PMID:32376409
      reference_title: "Liver Phenotypes of European Adults Heterozygous or Homozygous for Pi∗Z Variant of AAT (Pi∗MZ vs Pi∗ZZ genotype) and Noncarriers."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Obesity and diabetes were the most important factors associated with LSMs ≥7.1 kPa in subjects with the Pi∗MZ genotype."
      explanation: >-
        Identifies obesity and diabetes as the strongest measured correlates
        of raised liver stiffness in Pi*MZ adults. A stiffness proxy in a
        heterozygous cohort, one step off this node in two directions at once.
  description: >-
    Obesity and diabetes are important cofactors associated with elevated liver
    stiffness in Pi*MZ adults.
  effect: PROMOTES
  evidence:
  - reference: PMID:32376409
    reference_title: Liver Phenotypes of European Adults Heterozygous or Homozygous for Pi∗Z Variant of AAT (Pi∗MZ vs Pi∗ZZ genotype) and Noncarriers.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Obesity and diabetes were the most important factors associated with LSMs ≥7.1 kPa in subjects with the Pi∗MZ genotype."
    explanation: European Alpha-1 Liver Cohort identifies obesity and diabetes as the strongest measured correlates of elevated liver stiffness in Pi*MZ adults.

histopathology:
- name: PAS-Positive Diastase-Resistant Globules
  description: >-
    PAS-positive, diastase-resistant globules are a liver-biopsy finding used in
    AATD diagnosis, and hepatic globule burden can be reduced by fazirsiran.
  finding_term:
    preferred_term: PAS-positive diastase-resistant hepatocyte globules
    term:
      id: NCIT:C181557
      label: Hyaline Droplet Accumulation
  diagnostic: true
  evidence:
  - reference: PMID:26052388
    reference_title: Alpha-1 antitrypsin deficiency and the risk of hepatocellular carcinoma in end-stage liver disease.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A1ATD was diagnosed using phenotype characterization (MZ or ZZ), liver biopsy detection of PAS-positive diastase-resistant (PAS+) globules, or both."
    explanation: Cleveland Clinic ESLD cohort treats PAS+ diastase-resistant globules as a diagnostic histopathologic finding for AATD on liver biopsy.
  - reference: PMID:38964420
    reference_title: 'Fazirsiran for Adults With Alpha-1 Antitrypsin Deficiency Liver Disease: A Phase 2 Placebo Controlled Trial (SEQUOIA).'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "All fazirsiran-treated patients had histologic reduction from baseline in hepatic globule burden."
    explanation: SEQUOIA Phase 2 trial confirms hepatic globules are quantifiable and pharmacodynamically modifiable, anchoring globule burden as a histopathologic biomarker.
  notes: >-
    NCIT:C181557 (Hyaline Droplet Accumulation) is the closest available NCIT
    parent term under Morphologic Finding; NCIT does not currently provide a
    more specific term for AAT-associated PAS-positive diastase-resistant
    hepatocyte globules. Candidate for a future NCIT NTR.
animal_models:
- species: Mus musculus
  genotype: Full-length human PI*Z AAT transgenic mouse
  description: >-
    A full-length human PI*Z AAT transgenic mouse shows selective attenuation of
    unfolded-protein-response signaling branches.
  genes:
  - preferred_term: SERPINA1
    term:
      id: hgnc:8941
      label: SERPINA1
  associated_phenotypes:
  - Hepatic protein aggregation and selective unfolded-protein-response signaling
  evidence:
  - reference: PMID:35621045
    reference_title: The unfolded protein response to PI*Z alpha-1 antitrypsin in human hepatocellular and murine models.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Selective attenuation of UPR signaling branches was observed in PI*Z hAAT mice in which the protein kinase R-like ER kinase and inositol-requiring enzyme1α branches were suppressed while the activating transcription factor 6α branch remained active."
    explanation: The mouse experiment supports selective UPR-branch attenuation in vivo.
experimental_models:
- name: CRISPR-engineered Huh7.5Z hepatocyte cell line
  experimental_model_type: CELL_LINE
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  cell_source: CRISPR/Cas9-engineered Huh7.5 human hepatocellular cell line
  culture_system: Two-dimensional hepatocellular cell culture
  conditions:
  - PI*Z AAT compared with parental PI*MM AAT cells
  publication: PMID:35621045
  description: >-
    The CRISPR-engineered Huh7.5Z line shows UPR activation, caspase and
    apoptosis-marker activation, chaperone induction, and autophagy markers in
    a human hepatocellular background.
  modeled_mechanisms:
  - target: Hepatic Protein Aggregation
    description: PI*Z AAT expression produces the hepatocellular proteostasis lesion.
  - target: ER Stress and Unfolded Protein Response
    description: The line directly reports UPR activation and chaperone induction.
  - target: Hepatocyte Injury
    description: The line reports UPR, caspase, apoptosis, chaperone, and autophagy responses.
  evidence:
  - reference: PMID:35621045
    reference_title: The unfolded protein response to PI*Z alpha-1 antitrypsin in human hepatocellular and murine models.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Robust activation of UPR was observed in Huh7.5Z cells compared to Huh7.5 cells. Activated caspase cascade and apoptosis markers, increased chaperones, and autophagy markers were also detected in Z hepatocytes."
    explanation: The engineered human cell model directly recapitulates UPR and injury readouts.
discussions:
- discussion_id: gap_aatd_cutaneous_mechanism
  prompt: >-
    Which molecular intermediates connect systemic AAT deficiency to the
    neutrophilic inflammation and fat necrosis of AATD-associated panniculitis?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Neutrophilic Subcutaneous Inflammation
  rationale: >-
    Human biopsy establishes the lesion, but the cached disease-specific
    evidence does not justify a more specific protease-causal edge.
  evidence:
  - reference: PMID:33516773
    reference_title: Alpha-1 antitrypsin deficiency-associated panniculitis.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Evidence regarding management is limited to case reports and small case series."
    explanation: The systematic review documents the limited evidence base for this rare manifestation.
- discussion_id: gap_aatd_variable_penetrance
  prompt: >-
    Which genetic and environmental modifiers determine why only some people
    with the Pi*ZZ genotype progress to end-stage liver disease?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Hepatocyte Injury
  - pathophysiology#Hepatic Stellate Cell Activation
  rationale: >-
    Variable progression limits individual risk prediction and stratification
    for liver-directed therapy.
  evidence:
  - reference: PMID:28752441
    reference_title: Pathophysiology of Alpha-1 Antitrypsin Deficiency Liver Disease.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Since not all patients with the same homozygous PIZZ genotype develop end-stage disease, it is hypothesized that there is likely to be a strong influence of genetic and environmental modifiers of the injury cascade and of the fibrotic response."
    explanation: The review explicitly identifies unexplained modifier effects on liver-disease progression.
- discussion_id: gap_aatd_model_scope
  prompt: >-
    How faithfully do current hepatocyte and mouse systems predict the combined
    human pulmonary and hepatic disease, rather than only the hepatic PI*Z UPR arm?
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  attaches_to:
  - pathophysiology#Hepatic Protein Aggregation
  - pathophysiology#Protease-Antiprotease Imbalance in Lung
  rationale: >-
    Current models clarify hepatocyte UPR biology but do not establish that one
    system recapitulates both target organs or human clinical variability.
  evidence:
  - reference: PMID:35621045
    reference_title: The unfolded protein response to PI*Z alpha-1 antitrypsin in human hepatocellular and murine models.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "It has been unclear whether PI*Z AAT elicits liver cell UPR, due in part to limitations of current cellular and animal models."
    explanation: The study explicitly motivates new models because existing cellular and animal systems are limited.
clinical_trials:
- name: NCT03945292
  phase: PHASE_II
  status: COMPLETED
  description: >-
    SEQUOIA: Phase 2 randomized placebo-controlled trial of fazirsiran (TAK-999,
    ARO-AAT), an investigational subcutaneous siRNA targeting Z-AAT mRNA in
    hepatocytes, in adults with PiZZ AATD-associated liver disease. The study
    demonstrated dose-dependent reduction of serum and liver Z-AAT and
    histologic improvement in hepatic globule burden.
  target_phenotypes:
  - preferred_term: hepatic fibrosis
    term:
      id: HP:0001395
      label: Hepatic fibrosis
  - preferred_term: cirrhosis
    term:
      id: HP:0001394
      label: Cirrhosis
  evidence:
  - reference: clinicaltrials:NCT03945292
    reference_title: A Placebo-Controlled, Multi-dose, Phase 2 Study to Determine the Safety, Tolerability and Pharmacodynamic Effect of Fazirsiran (TAK-999, ARO-AAT) in Patients With Alpha-1 Antitrypsin Deficiency (AATD) [SEQUOIA]
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The purpose of AROAAT2001 (SEQUOIA) is to evaluate the safety, efficacy and tolerability of multiple doses of the investigational product, Fazirsiran Injection, administered subcutaneously to participants with alpha-1 antitrypsin deficiency (AATD)."
    explanation: ClinicalTrials.gov record confirms the SEQUOIA trial design and population for the fazirsiran Phase 2 study.
  - reference: PMID:38964420
    reference_title: 'Fazirsiran for Adults With Alpha-1 Antitrypsin Deficiency Liver Disease: A Phase 2 Placebo Controlled Trial (SEQUOIA).'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We evaluated the safety and efficacy of an investigational RNA interference therapeutic, fazirsiran, that degrades Z-AAT messenger RNA, reducing deleterious protein synthesis."
    explanation: Peer-reviewed publication of SEQUOIA describes mechanism and outcomes of the trial intervention.
- name: NCT04180319
  phase: NOT_APPLICABLE
  status: UNKNOWN
  description: >-
    EARCO is a pan-European observational registry intended to provide
    longitudinal real-world data on severe AATD.
  target_phenotypes:
  - preferred_term: emphysema
    term:
      id: HP:0002097
      label: Emphysema
  evidence:
  - reference: clinicaltrials:NCT04180319
    reference_title: A Pan-European Multi-Centre Observational Study To Determine The Natural History Of Patients With Alpha-1 Antitrypsin
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The core project is the pan-European AATD Registry, a collaboration which will offer longitudinal real-world data for patients with AATD."
    explanation: ClinicalTrials.gov describes the registry and its longitudinal real-world purpose.
- name: NCT05856331
  phase: PHASE_II
  status: COMPLETED
  description: >-
    ELEVAATE is a Phase 2 comparison of SAR447537 (INBRX-101) with
    plasma-derived A1PI therapy in adults with AATD emphysema.
  target_phenotypes:
  - preferred_term: emphysema
    term:
      id: HP:0002097
      label: Emphysema
  evidence:
  - reference: clinicaltrials:NCT05856331
    reference_title: Phase 2, Double-Blind, Randomized, Active-Control, Parallel Group Study to Assess the Pharmacokinetics, Pharmacodynamics, Immunogenicity, and Safety of SAR447537 (INBRX-101) Compared to Plasma-Derived Alpha1-Proteinase Inhibitor (A1PI) Augmentation Therapy in Adults With Alpha-1 Antitrypsin Deficiency (AATD) Emphysema
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Phase 2 study to compare SAR447537 (INBRX-101) to plasma derived A1PI therapy in adults with AATD emphysema"
    explanation: ClinicalTrials.gov record confirms the ELEVAATE Phase 2 active-controlled trial of recombinant long-acting A1PI vs plasma-derived augmentation.

notes: >-
  This entry distinguishes the loss-of-antiprotease pulmonary arm from the
  toxic-gain-of-function hepatic arm. Quantitative phenotype frequencies are
  omitted where the available evidence is genotype-, age-, or referral-cohort
  dependent. Emerging gene, cell, and regenerative therapies remain research
  leads unless represented by a verified trial or peer-reviewed human study.
  Differential diagnoses without cache-backed distinguishing criteria are not
  represented as structured entries; the focused differential instead records
  evidence-supported features that separate AATD from smoking-related COPD.
datasets:
- accession: geo:GSE109515
  title: The Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis Study (GRADS)  Alpha-1 study [A1AT]
  description: Whole genome mRNA and microRNA profiling of bronchoalveolar lavage (BAL) and peripheral blood mononuclear cell (PBMC) in Alpha-1 Antitrypsin Deficiency patients with PiZZ or PiMZ alpha-1 antitrypsin genotypes
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  data_type: BULK_RNA_SEQ
  sample_count: 178
  publication: PMID:33303696
  notes: Identified by GEO DataSets index search for Alpha-1 Antitrypsin Deficiency (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
- accession: geo:GSE140732
  title: A Highly Phenotyped Open Access Repository of Alpha-1 Antitrypsin Deficiency Pluripotent Stem Cells
  description: We profiled the global transcriptomes of 10 featured AATD-patient specific iPSC that underwent directed differentiation towards a hepatic and lung lineage. We used digital gene expression (DGE), a platform for high-fidelity RNA sequencing, and in addition to differentiated iPSC-derived cell types mentioned above (iHeps and iPSC-Lung progenitors), we also collected RNA from undifferentiated iPSCs and from a panel of primary adult human hepatocytes (PHH) for comparison.
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  data_type: BULK_RNA_SEQ
  sample_count: 96
  publication: PMID:32619491
  notes: Identified by GEO DataSets index search for Alpha-1 Antitrypsin Deficiency (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
references:
- reference: PMID:20301692
  title: "Alpha-1 Antitrypsin Deficiency."
  tags:
  - GeneReviews
  findings: []
- reference: DOI:10.1164/rccm.202307-1171ed
  title: Undiagnosed Alpha-1 Antitrypsin Deficiency and the Perpetuation of Lung Health Inequity
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: Undiagnosed Alpha-1 Antitrypsin Deficiency and the Perpetuation of Lung Health Inequity
    supporting_text: Undiagnosed Alpha-1 Antitrypsin Deficiency and the Perpetuation of Lung Health Inequity
- reference: DOI:10.1177/17534666251318841
  title: Advancing the understanding and treatment of lung pathologies associated with alpha 1 antitrypsin deficiency
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: Alpha 1 antitrypsin deficiency (AATD) is a genetic disorder that alters the functionality and/or serum levels of alpha 1 antitrypsin (AAT).
    supporting_text: Alpha 1 antitrypsin deficiency (AATD) is a genetic disorder that alters the functionality and/or serum levels of alpha 1 antitrypsin (AAT).
- reference: DOI:10.1183/16000617.0170-2023
  title: 'Nine controversial questions about augmentation therapy for alpha-1 antitrypsin deficiency: a viewpoint'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: Augmentation therapy with intravenous alpha-1 antitrypsin is the only specific treatment for alpha-1 antitrypsin deficiency (AATD)-associated emphysema.
    supporting_text: Augmentation therapy with intravenous alpha-1 antitrypsin is the only specific treatment for alpha-1 antitrypsin deficiency (AATD)-associated emphysema.
- reference: DOI:10.1186/s13023-024-03069-1
  title: 'Rare variants in alpha 1 antitrypsin deficiency: a systematic literature review'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: Alpha 1 Antitrypsin Deficiency (AATD) is a largely underrecognized genetic condition characterized by low Alpha 1 Antitrypsin (AAT) serum levels, resulting from variations in SERPINA1.
    supporting_text: Alpha 1 Antitrypsin Deficiency (AATD) is a largely underrecognized genetic condition characterized by low Alpha 1 Antitrypsin (AAT) serum levels, resulting from variations in SERPINA1.
- reference: DOI:10.14218/jcth.2024.00201
  title: Liver Characterization of a Cohort of Alpha-1 Antitrypsin Deficiency Patients with and without Lung Disease
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: Liver Characterization of a Cohort of Alpha-1 Antitrypsin Deficiency Patients with and without Lung Disease
    supporting_text: Liver Characterization of a Cohort of Alpha-1 Antitrypsin Deficiency Patients with and without Lung Disease
- reference: DOI:10.15326/jcopdf.2022.0339
  title: Quality of Life and Mortality Outcomes for Augmentation Naïve and Augmented Patients with Severe Alpha-1 Antitrypsin Deficiency
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: Quality of Life and Mortality Outcomes for Augmentation Naïve and Augmented Patients with Severe Alpha-1 Antitrypsin Deficiency
    supporting_text: Quality of Life and Mortality Outcomes for Augmentation Naïve and Augmented Patients with Severe Alpha-1 Antitrypsin Deficiency
- reference: DOI:10.3389/fimmu.2024.1443297
  title: 'Immunological and homeostatic pathways of alpha -1 antitrypsin: a new therapeutic potential'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: α -1 antitrypsin (A1AT) is a 52 kDa acute-phase glycoprotein belonging to the serine protease inhibitor superfamily (SERPIN).
    supporting_text: α -1 antitrypsin (A1AT) is a 52 kDa acute-phase glycoprotein belonging to the serine protease inhibitor superfamily (SERPIN).
- reference: DOI:10.3390/ijms26178504
  title: 'Next-Generation Regenerative Therapies for Alpha-1 Antitrypsin Deficiency: Molecular Pathogenesis to Clinical Translation'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: Alpha-1 antitrypsin deficiency (AATD) represents a paradigmatic genetic disorder with well-characterized hepatic manifestations but relatively underexplored pulmonary implications.
    supporting_text: Alpha-1 antitrypsin deficiency (AATD) represents a paradigmatic genetic disorder with well-characterized hepatic manifestations but relatively underexplored pulmonary implications.
- reference: DOI:10.3390/medicina62040639
  title: Alpha-1 Antitrypsin Deficiency-Associated Chronic Obstructive Pulmonary Disease
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Alpha-1 Antitrypsin Deficiency-Associated Chronic Obstructive Pulmonary Disease
    supporting_text: Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by reduced circulating levels and/or impaired function of alpha-1 antitrypsin (AAT), a key serine protease inhibitor, in which loss of effective antiprotease protection results in unchecked neutrophil elastase activity and progressive lung tissue destruction.
- reference: DOI:10.36416/1806-3756/e20240235
  title: Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency
    supporting_text: Alpha-1 antitrypsin deficiency (AATD) is a relatively rare genetic disorder, inherited in an autosomal codominant manner, that results in reduced serum AAT concentrations, with a consequent reduction in antielastase activity in the lungs, as well as an increased risk of diseases such as pulmonary emphysema, liver cirrhosis, and necrotizing panniculitis.
- reference: DOI:10.7573/dic.2023-3-1
  title: 'Diagnosis and augmentation therapy for alpha-1 antitrypsin deficiency: current knowledge and future potential'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-falcon.md
  findings:
  - statement: 'Diagnosis and augmentation therapy for alpha-1 antitrypsin deficiency: current knowledge and future potential'
    supporting_text: 'Diagnosis and augmentation therapy for alpha-1 antitrypsin deficiency: current knowledge and future potential'
- reference: PMID:10677536
  title: 'Chemical chaperones mediate increased secretion of mutant alpha 1-antitrypsin (alpha 1-AT) Z: A potential pharmacological strategy for prevention of liver injury and emphysema in alpha 1-AT deficiency.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'In alpha1-AT deficiency, a misfolded but functionally active mutant alpha1-ATZ (alpha1-ATZ) molecule is retained in the endoplasmic reticulum of liver cells rather than secreted into the blood and body fluids.'
    supporting_text: 'In alpha1-AT deficiency, a misfolded but functionally active mutant alpha1-ATZ (alpha1-ATZ) molecule is retained in the endoplasmic reticulum of liver cells rather than secreted into the blood and body fluids.'
- reference: PMID:20667823
  title: Loop-sheet mechanism of serpin polymerization tested by reactive center loop mutations.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'The serpin mechanism of protease inhibition involves the rapid and stable incorporation of the reactive center loop (RCL) into central β-sheet A.'
    supporting_text: 'The serpin mechanism of protease inhibition involves the rapid and stable incorporation of the reactive center loop (RCL) into central β-sheet A.'
- reference: PMID:20731544
  title: Molecular contortionism - on the physical limits of serpin 'loop-sheet' polymers.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Members of the serpin (serine protease inhibitor) superfamily fold into a metastable conformation that is crucial for proper function.'
    supporting_text: 'Members of the serpin (serine protease inhibitor) superfamily fold into a metastable conformation that is crucial for proper function.'
- reference: PMID:21617532
  title: Performance of enhanced liver fibrosis plasma markers in asymptomatic individuals with ZZ α1-antitrypsin deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha1-antitrypsin deficiency (AATD) is a common genetic cause of chronic liver disease.'
    supporting_text: 'Alpha1-antitrypsin deficiency (AATD) is a common genetic cause of chronic liver disease.'
- reference: PMID:24121147
  title: Appropriateness of newborn screening for α1-antitrypsin deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'The Alpha-1 Foundation convened a workshop to consider the appropriateness of newborn screening for α-1-antitrypsin (AAT) deficiency.'
    supporting_text: 'The Alpha-1 Foundation convened a workshop to consider the appropriateness of newborn screening for α-1-antitrypsin (AAT) deficiency.'
- reference: PMID:25518532
  title: 'Alpha-1-antitrypsin deficiency in children: clinical characteristics and diagnosis.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha-1-antitrypsin deficiency (AATD) is a relatively rare and clinically very heterogeneous autosomal recessive disorder.'
    supporting_text: 'Alpha-1-antitrypsin deficiency (AATD) is a relatively rare and clinically very heterogeneous autosomal recessive disorder.'
- reference: PMID:26527439
  title: 'Unusual Acute Sequelae of α1-Antitrypsin Deficiency: A Myriad of Symptoms With One Common Cure.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Panniculitis associated with α1-antitrypsin deficiency (AATD) is well documented but rare.'
    supporting_text: 'Panniculitis associated with α1-antitrypsin deficiency (AATD) is well documented but rare.'
- reference: PMID:27296815
  title: 'Alpha-1-antitrypsin (SERPINA1) mutation spectrum: Three novel variants and haplotype characterization of rare deficiency alleles identified in Portugal.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Alpha-1-antitrypsin deficiency (AATD) is a genetic condition caused by SERPINA1 mutations, which culminates into lower protease inhibitor activity in the serum and predisposes affected individuals to emphysema.
    supporting_text: Alpha-1-antitrypsin deficiency (AATD) is a genetic condition caused by SERPINA1 mutations, which culminates into lower protease inhibitor activity in the serum and predisposes affected individuals to emphysema.
- reference: PMID:27465791
  title: α1-Antitrypsin deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'α1-Antitrypsin deficiency (A1ATD) is an inherited disorder caused by mutations in SERPINA1, leading to liver and lung disease.'
    supporting_text: 'α1-Antitrypsin deficiency (A1ATD) is an inherited disorder caused by mutations in SERPINA1, leading to liver and lung disease.'
- reference: PMID:28058497
  title: '[A rare cause of severe panniculitis].'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'A 58-year-old patient presented with a severe, episodic panniculitis of the upper legs.'
    supporting_text: 'A 58-year-old patient presented with a severe, episodic panniculitis of the upper legs.'
- reference: PMID:28073160
  title: Activation of the c-Jun N-terminal kinase pathway aggravates proteotoxicity of hepatic mutant Z alpha1-antitrypsin.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha1-antitrypsin deficiency is a genetic disease that can affect both the lung and the liver.'
    supporting_text: 'Alpha1-antitrypsin deficiency is a genetic disease that can affect both the lung and the liver.'
- reference: PMID:28496314
  title: 'Treatment of lung disease in alpha-1 antitrypsin deficiency: a systematic review.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Alpha-1 antitrypsin deficiency (AATD) is a rare genetic condition predisposing individuals to chronic obstructive pulmonary disease (COPD).
    supporting_text: Alpha-1 antitrypsin deficiency (AATD) is a rare genetic condition predisposing individuals to chronic obstructive pulmonary disease (COPD).
- reference: PMID:28927525
  title: 'Alpha-1-antitrypsin deficiency: Genetic variations, clinical manifestations and therapeutic interventions.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha-1-antitrypsin (AAT) is an acute phase secretory glycoprotein that inhibits neutrophil proteases like elastase and is considered as the archetype of a family of structurally related serine-protease inhibitors termed serpins.'
    supporting_text: 'Alpha-1-antitrypsin (AAT) is an acute phase secretory glycoprotein that inhibits neutrophil proteases like elastase and is considered as the archetype of a family of structurally related serine-protease inhibitors termed serpins.'
- reference: PMID:29070580
  title: COPD in individuals with the PiMZ alpha-1 antitrypsin genotype.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'COPD in individuals with the PiMZ alpha-1 antitrypsin genotype'
    supporting_text: 'Since the discovery of severe alpha-1 antitrypsin deficiency as a genetic risk factor for emphysema, there has been ongoing debate over whether individuals with intermediate deficiency with one protease inhibitor Z allele (PiMZ, or MZ) are at some risk for emphysema.'
- reference: PMID:29430176
  title: 'Alpha 1 antitrypsin to treat lung disease in alpha 1 antitrypsin deficiency: recent developments and clinical implications.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Reduced levels of AAT allow abnormal degradation of lung tissue, which may ultimately lead to the development of early-onset emphysema.'
    supporting_text: 'Reduced levels of AAT allow abnormal degradation of lung tissue, which may ultimately lead to the development of early-onset emphysema.'
- reference: PMID:29572094
  title: Hepatic-targeted RNA interference provides robust and persistent knockdown of alpha-1 antitrypsin levels in ZZ patients.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder causing pulmonary and liver disease.'
    supporting_text: 'Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder causing pulmonary and liver disease.'
- reference: PMID:30066494
  title: 'Hepatopulmonary Syndrome in Children: A 20-Year Review of Presenting Symptoms, Clinical Progression, and Transplant Outcome.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Hepatopulmonary syndrome (HPS) in stable patients with cirrhosis can easily be overlooked.'
    supporting_text: 'Hepatopulmonary syndrome (HPS) in stable patients with cirrhosis can easily be overlooked.'
- reference: PMID:31556146
  title: 'Technique and outcome of domino liver transplantation from patients with maple syrup urine disease: Expanding the donor pool for live donor liver transplantation.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Domino liver transplantation (DLT) using liver allografts from patients with metabolic disorders enhances organ utilization.
    supporting_text: Domino liver transplantation (DLT) using liver allografts from patients with metabolic disorders enhances organ utilization.
- reference: PMID:32062078
  title: Does heart surgery change the capacity of α1-antitrypsin to inhibit the ATP-induced release of monocytic interleukin-1β? A preliminary study.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Heart surgery involving cardiopulmonary bypass induces systemic inflammation that is, at least in part, caused by extracellular ATP originating from damaged cells and by proteases secreted by activated neutrophils.'
    supporting_text: 'Heart surgery involving cardiopulmonary bypass induces systemic inflammation that is, at least in part, caused by extracellular ATP originating from damaged cells and by proteases secreted by activated neutrophils.'
- reference: PMID:32621460
  title: Why is Disease Penetration So Variable? Role of Genetic Modifiers of Lung Function in Alpha-1 Antitrypsin Deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Individuals with alpha-1 antitrypsin deficiency (AATD) have marked heterogeneity in lung function, suspected to be related to a combination of both environmental (e.g., cigarette smoking) and genetic factors.'
    supporting_text: 'Individuals with alpha-1 antitrypsin deficiency (AATD) have marked heterogeneity in lung function, suspected to be related to a combination of both environmental (e.g., cigarette smoking) and genetic factors.'
- reference: PMID:32723872
  title: CHOP and c-JUN up-regulate the mutant Z α(1)-antitrypsin, exacerbating its aggregation and liver proteotoxicity.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'α1-Antitrypsin (AAT) encoded by the SERPINA1 gene is an acute-phase protein synthesized in the liver and secreted into the circulation.'
    supporting_text: 'α1-Antitrypsin (AAT) encoded by the SERPINA1 gene is an acute-phase protein synthesized in the liver and secreted into the circulation.'
- reference: PMID:32726073
  title: The Alpha-1 Antitrypsin Polymer Load Correlates With Hepatocyte Senescence, Fibrosis Stage and Liver-Related Mortality.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Alpha-1 antitrypsin deficiency (AATD) is an important, inherited cause of chronic liver disease.
    supporting_text: Alpha-1 antitrypsin deficiency (AATD) is an important, inherited cause of chronic liver disease.
- reference: PMID:32911139
  title: Clinical outcomes and survival following lung transplantation in patients with Alpha-1 antitrypsin deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'The primary intention of our study is to describe disease-specific outcomes in patients with alpha-1 antitrypsin deficiency (AATD) following lung transplantation (LT).'
    supporting_text: 'The primary intention of our study is to describe disease-specific outcomes in patients with alpha-1 antitrypsin deficiency (AATD) following lung transplantation (LT).'
- reference: PMID:33139195
  title: Long term results of liver transplantation for alpha-1 antitrypsin deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Liver transplantation (LT) is the therapeutic option for end-stage liver disease associated with alpha1 antitrypsin (A1AT) deficiency.'
    supporting_text: 'Liver transplantation (LT) is the therapeutic option for end-stage liver disease associated with alpha1 antitrypsin (A1AT) deficiency.'
- reference: PMID:33239231
  title: 'Hypothesis: Alpha-1-antitrypsin is a promising treatment option for COVID-19.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'No definitive treatment for COVID-19 exists although promising results have been reported with remdesivir and glucocorticoids.'
    supporting_text: 'No definitive treatment for COVID-19 exists although promising results have been reported with remdesivir and glucocorticoids.'
- reference: PMID:33649241
  title: Up-regulation of miR-34b/c by JNK and FOXO3 protects from liver fibrosis.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'α1-Antitrypsin (AAT) deficiency is a common genetic disease presenting with lung and liver diseases.'
    supporting_text: 'α1-Antitrypsin (AAT) deficiency is a common genetic disease presenting with lung and liver diseases.'
- reference: PMID:35621045
  title: The unfolded protein response to PI*Z alpha-1 antitrypsin in human hepatocellular and murine models.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha-1 antitrypsin (AAT) deficiency (AATD) is an inherited disease caused by mutations in the serpin family A member 1 (SERPINA1, also known as AAT) gene.'
    supporting_text: 'Alpha-1 antitrypsin (AAT) deficiency (AATD) is an inherited disease caused by mutations in the serpin family A member 1 (SERPINA1, also known as AAT) gene.'
- reference: PMID:35730566
  title: Alu RNA induces NLRP3 expression through TLR7 activation in α-1-antitrypsin-deficient macrophages.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'α-1 antitrypsin (AAT) is a serine protease inhibitor that plays a pivotal role in maintaining lung homeostasis.'
    supporting_text: 'α-1 antitrypsin (AAT) is a serine protease inhibitor that plays a pivotal role in maintaining lung homeostasis.'
- reference: PMID:38294851
  title: The p24-family and COPII subunit SEC24C facilitate the clearance of alpha1-antitrypsin Z from the endoplasmic reticulum to lysosomes.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'A subpopulation of the alpha-1-antitrypsin misfolding Z mutant (ATZ) is cleared from the endoplasmic reticulum (ER) via an ER-to-lysosome-associated degradation (ERLAD) pathway.'
    supporting_text: 'A subpopulation of the alpha-1-antitrypsin misfolding Z mutant (ATZ) is cleared from the endoplasmic reticulum (ER) via an ER-to-lysosome-associated degradation (ERLAD) pathway.'
- reference: PMID:38336172
  title: Multiple Genes Core to ERAD, Macroautophagy and Lysosomal Degradation Pathways Participate in the Proteostasis Response in α1-Antitrypsin Deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'In the classic form of α1-antitrypsin deficiency (ATD), the misfolded α1-antitrypsin Z (ATZ) variant accumulates in the endoplasmic reticulum (ER) of liver cells.'
    supporting_text: 'In the classic form of α1-antitrypsin deficiency (ATD), the misfolded α1-antitrypsin Z (ATZ) variant accumulates in the endoplasmic reticulum (ER) of liver cells.'
- reference: PMID:38599244
  title: Pulmonary manifestations of alpha 1 antitrypsin deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha 1 antitrypsin deficiency is a widely under recognized autosomal codominant condition caused by genetic mutations in the SERPINA 1 gene, which encodes for alpha 1 antitrypsin (AAT), a serine protease inhibitor.'
    supporting_text: 'Alpha 1 antitrypsin deficiency is a widely under recognized autosomal codominant condition caused by genetic mutations in the SERPINA 1 gene, which encodes for alpha 1 antitrypsin (AAT), a serine protease inhibitor.'
- reference: PMID:38992821
  title: Differences in bile acid profiles between cholestatic diseases - Development of a high throughput assay for dried bloodspots.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Cholestasis causes accumulation of bile acids (BAs) and changes the circulating bile acid profile.
    supporting_text: Cholestasis causes accumulation of bile acids (BAs) and changes the circulating bile acid profile.
- reference: PMID:40378984
  title: Insulin-like Growth Factor-1 Reflects Liver Disease Stage and Improves Prediction of Liver-related Mortality.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Liver-related mortality represents a growing public health concern, disproportionately affecting younger subjects.'
    supporting_text: 'Liver-related mortality represents a growing public health concern, disproportionately affecting younger subjects.'
- reference: PMID:40550287
  title: Sleep apnea among individuals with Alpha-1 antitrypsin deficiency-associated lung disease.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha-1 antitrypsin deficiency (AATD) is a genetic condition that has high rates of associated COPD.'
    supporting_text: 'Alpha-1 antitrypsin deficiency (AATD) is a genetic condition that has high rates of associated COPD.'
- reference: PMID:40563447
  title: 'Alpha-1 Antitrypsin Deficiency and Bronchial Asthma: Current Challenges.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha-1 antitrypsin deficiency (AATD) is a rare genetic condition classically associated with pulmonary emphysema and liver disease.'
    supporting_text: 'Alpha-1 antitrypsin deficiency (AATD) is a rare genetic condition classically associated with pulmonary emphysema and liver disease.'
- reference: PMID:40665347
  title: Assessing inflammatory protein biomarkers in COPD subjects with and without alpha-1 antitrypsin deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Individuals homozygous for the Alpha-1 Antitrypsin (AAT) Z allele (Pi*ZZ) exhibit heterogeneity in COPD risk.'
    supporting_text: 'Individuals homozygous for the Alpha-1 Antitrypsin (AAT) Z allele (Pi*ZZ) exhibit heterogeneity in COPD risk.'
- reference: PMID:40888606
  title: 'Increased Risk of Cholesteatoma in Individuals With Alpha-1 Antitrypsin Deficiency: A Cohort Study.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'To estimate the risk of cholesteatoma in patients with alpha-1 antitrypsin deficiency (AATD) compared to the general population using time-to-event analysis.'
    supporting_text: 'To estimate the risk of cholesteatoma in patients with alpha-1 antitrypsin deficiency (AATD) compared to the general population using time-to-event analysis.'
- reference: PMID:40967767
  title: Two randomised controlled phase 2 studies of the oral neutrophil elastase inhibitor alvelestat in alpha-1 antitrypsin deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder that causes emphysema from lack of the alpha-1 antitrypsin (AAT) serpin antiprotease, leading to protease-antiprotease imbalance.
    supporting_text: Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder that causes emphysema from lack of the alpha-1 antitrypsin (AAT) serpin antiprotease, leading to protease-antiprotease imbalance.
- reference: PMID:41216004
  title: The Epidemiology of Alpha-1 Antitrypsin Deficiency in Norway.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Alpha-1 antitrypsin deficiency (AATD) is a genetic condition characterized by insufficient levels of alpha-1 antitrypsin and elevated risk of lung and liver disease.
    supporting_text: Alpha-1 antitrypsin deficiency (AATD) is a genetic condition characterized by insufficient levels of alpha-1 antitrypsin and elevated risk of lung and liver disease.
- reference: PMID:41364209
  title: 'Quantitative CT of emphysema, wall thickness and mucus plugs in alpha-1-antitrypsin deficiency: relationship to clinical outcomes.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha-1-antitrypsin deficiency (AATD) is a rare genetic disorder leading to chronic obstructive pulmonary disease (COPD).'
    supporting_text: 'Alpha-1-antitrypsin deficiency (AATD) is a rare genetic disorder leading to chronic obstructive pulmonary disease (COPD).'
- reference: PMID:41789803
  title: Novel mutation (M(angera)-E288V) in alpha-1 antitrypsin deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Alpha-1 antitrypsin deficiency is an autosomal, codominant disorder caused by mutations of the SERPINA1 gene.
    supporting_text: Alpha-1 antitrypsin deficiency is an autosomal, codominant disorder caused by mutations of the SERPINA1 gene.
- reference: PMID:41791905
  title: 'Prevalence of liver disease and liver transplantation in pediatric ZZ alpha-1 antitrypsin deficiency: A systematic review and meta-analysis.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Pediatric Pi*ZZ alpha-1 antitrypsin deficiency (A1ATD) can cause hepatocyte A1AT polymer retention and progressive liver injury, but estimates of childhood liver morbidity vary across studies and remain poorly defined.
    supporting_text: Pediatric Pi*ZZ alpha-1 antitrypsin deficiency (A1ATD) can cause hepatocyte A1AT polymer retention and progressive liver injury, but estimates of childhood liver morbidity vary across studies and remain poorly defined.
- reference: PMID:41883848
  title: Decalogue of Best Practices in Alpha-1 Antitrypsin Deficiency.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha-1 antitrypsin (AAT) deficiency is an underdiagnosed genetic disorder that predisposes individuals to the development of pulmonary emphysema and liver disease.'
    supporting_text: 'Alpha-1 antitrypsin (AAT) deficiency is an underdiagnosed genetic disorder that predisposes individuals to the development of pulmonary emphysema and liver disease.'
- reference: PMID:42072628
  title: Adaptive Regulation of mTOR Activity by AMPK, Akt, and ATF6 Pathways in Pi*Z Alpha-1 Antitrypsin Deficient Hepatocytes.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: 'Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder characterized by intracellular retention of mutant Z (Pi*Z) alpha-1 antitrypsin (AAT) within hepatocytes, resulting in progressive liver disease.'
    supporting_text: 'Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder characterized by intracellular retention of mutant Z (Pi*Z) alpha-1 antitrypsin (AAT) within hepatocytes, resulting in progressive liver disease.'
- reference: PMID:8578172
  title: Prognosis and life expectancy on alpha-1-antitrypsin deficiency and chronic liver disease.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings:
  - statement: Alpha-1-antitrypsin deficiency is a common autosomal recessive disorder associated with early development of emphysema, liver cirrhosis, and hepatocellular carcinoma.
    supporting_text: Alpha-1-antitrypsin deficiency is a common autosomal recessive disorder associated with early development of emphysema, liver cirrhosis, and hepatocellular carcinoma.
- reference: PMID:28752441
  title: Pathophysiology of Alpha-1 Antitrypsin Deficiency Liver Disease.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings: []
- reference: PMID:40943425
  title: 'Next-Generation Regenerative Therapies for Alpha-1 Antitrypsin Deficiency: Molecular Pathogenesis to Clinical Translation.'
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings: []
- reference: PMID:42075511
  title: Alpha-1 Antitrypsin Deficiency-Associated Chronic Obstructive Pulmonary Disease.
  found_in:
  - Alpha_1_Antitrypsin_Deficiency-deep-research-openscientist.md
  findings: []
📚

References & Deep Research

References

60
PMID:20301692
Alpha-1 Antitrypsin Deficiency.
No top-level findings curated for this source.
DOI:10.1164/rccm.202307-1171ed
Undiagnosed Alpha-1 Antitrypsin Deficiency and the Perpetuation of Lung Health Inequity
1 finding
Undiagnosed Alpha-1 Antitrypsin Deficiency and the Perpetuation of Lung Health Inequity
"Undiagnosed Alpha-1 Antitrypsin Deficiency and the Perpetuation of Lung Health Inequity"
DOI:10.1177/17534666251318841
Advancing the understanding and treatment of lung pathologies associated with alpha 1 antitrypsin deficiency
1 finding
Alpha 1 antitrypsin deficiency (AATD) is a genetic disorder that alters the functionality and/or serum levels of alpha 1 antitrypsin (AAT).
"Alpha 1 antitrypsin deficiency (AATD) is a genetic disorder that alters the functionality and/or serum levels of alpha 1 antitrypsin (AAT)."
DOI:10.1183/16000617.0170-2023
Nine controversial questions about augmentation therapy for alpha-1 antitrypsin deficiency: a viewpoint
1 finding
Augmentation therapy with intravenous alpha-1 antitrypsin is the only specific treatment for alpha-1 antitrypsin deficiency (AATD)-associated emphysema.
"Augmentation therapy with intravenous alpha-1 antitrypsin is the only specific treatment for alpha-1 antitrypsin deficiency (AATD)-associated emphysema."
DOI:10.1186/s13023-024-03069-1
Rare variants in alpha 1 antitrypsin deficiency: a systematic literature review
1 finding
Alpha 1 Antitrypsin Deficiency (AATD) is a largely underrecognized genetic condition characterized by low Alpha 1 Antitrypsin (AAT) serum levels, resulting from variations in SERPINA1.
"Alpha 1 Antitrypsin Deficiency (AATD) is a largely underrecognized genetic condition characterized by low Alpha 1 Antitrypsin (AAT) serum levels, resulting from variations in SERPINA1."
DOI:10.14218/jcth.2024.00201
Liver Characterization of a Cohort of Alpha-1 Antitrypsin Deficiency Patients with and without Lung Disease
1 finding
Liver Characterization of a Cohort of Alpha-1 Antitrypsin Deficiency Patients with and without Lung Disease
"Liver Characterization of a Cohort of Alpha-1 Antitrypsin Deficiency Patients with and without Lung Disease"
DOI:10.15326/jcopdf.2022.0339
Quality of Life and Mortality Outcomes for Augmentation Naïve and Augmented Patients with Severe Alpha-1 Antitrypsin Deficiency
1 finding
Quality of Life and Mortality Outcomes for Augmentation Naïve and Augmented Patients with Severe Alpha-1 Antitrypsin Deficiency
"Quality of Life and Mortality Outcomes for Augmentation Naïve and Augmented Patients with Severe Alpha-1 Antitrypsin Deficiency"
DOI:10.3389/fimmu.2024.1443297
Immunological and homeostatic pathways of alpha -1 antitrypsin: a new therapeutic potential
1 finding
α -1 antitrypsin (A1AT) is a 52 kDa acute-phase glycoprotein belonging to the serine protease inhibitor superfamily (SERPIN).
"α -1 antitrypsin (A1AT) is a 52 kDa acute-phase glycoprotein belonging to the serine protease inhibitor superfamily (SERPIN)."
DOI:10.3390/ijms26178504
Next-Generation Regenerative Therapies for Alpha-1 Antitrypsin Deficiency: Molecular Pathogenesis to Clinical Translation
1 finding
Alpha-1 antitrypsin deficiency (AATD) represents a paradigmatic genetic disorder with well-characterized hepatic manifestations but relatively underexplored pulmonary implications.
"Alpha-1 antitrypsin deficiency (AATD) represents a paradigmatic genetic disorder with well-characterized hepatic manifestations but relatively underexplored pulmonary implications."
DOI:10.3390/medicina62040639
Alpha-1 Antitrypsin Deficiency-Associated Chronic Obstructive Pulmonary Disease
1 finding
Alpha-1 Antitrypsin Deficiency-Associated Chronic Obstructive Pulmonary Disease
"Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by reduced circulating levels and/or impaired function of alpha-1 antitrypsin (AAT), a key serine protease inhibitor, in which loss of effective antiprotease protection results in unchecked neutrophil elastase activity and..."
DOI:10.36416/1806-3756/e20240235
Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency
1 finding
Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency
"Alpha-1 antitrypsin deficiency (AATD) is a relatively rare genetic disorder, inherited in an autosomal codominant manner, that results in reduced serum AAT concentrations, with a consequent reduction in antielastase activity in the lungs, as well as an increased risk of diseases such as..."
DOI:10.7573/dic.2023-3-1
Diagnosis and augmentation therapy for alpha-1 antitrypsin deficiency: current knowledge and future potential
1 finding
Diagnosis and augmentation therapy for alpha-1 antitrypsin deficiency: current knowledge and future potential
"Diagnosis and augmentation therapy for alpha-1 antitrypsin deficiency: current knowledge and future potential"
PMID:10677536
Chemical chaperones mediate increased secretion of mutant alpha 1-antitrypsin (alpha 1-AT) Z: A potential pharmacological strategy for prevention of liver injury and emphysema in alpha 1-AT deficiency.
1 finding
In alpha1-AT deficiency, a misfolded but functionally active mutant alpha1-ATZ (alpha1-ATZ) molecule is retained in the endoplasmic reticulum of liver cells rather than secreted into the blood and body fluids.
"In alpha1-AT deficiency, a misfolded but functionally active mutant alpha1-ATZ (alpha1-ATZ) molecule is retained in the endoplasmic reticulum of liver cells rather than secreted into the blood and body fluids."
PMID:20667823
Loop-sheet mechanism of serpin polymerization tested by reactive center loop mutations.
1 finding
The serpin mechanism of protease inhibition involves the rapid and stable incorporation of the reactive center loop (RCL) into central β-sheet A.
"The serpin mechanism of protease inhibition involves the rapid and stable incorporation of the reactive center loop (RCL) into central β-sheet A."
PMID:20731544
Molecular contortionism - on the physical limits of serpin 'loop-sheet' polymers.
1 finding
Members of the serpin (serine protease inhibitor) superfamily fold into a metastable conformation that is crucial for proper function.
"Members of the serpin (serine protease inhibitor) superfamily fold into a metastable conformation that is crucial for proper function."
PMID:21617532
Performance of enhanced liver fibrosis plasma markers in asymptomatic individuals with ZZ α1-antitrypsin deficiency.
1 finding
Alpha1-antitrypsin deficiency (AATD) is a common genetic cause of chronic liver disease.
"Alpha1-antitrypsin deficiency (AATD) is a common genetic cause of chronic liver disease."
PMID:24121147
Appropriateness of newborn screening for α1-antitrypsin deficiency.
1 finding
The Alpha-1 Foundation convened a workshop to consider the appropriateness of newborn screening for α-1-antitrypsin (AAT) deficiency.
"The Alpha-1 Foundation convened a workshop to consider the appropriateness of newborn screening for α-1-antitrypsin (AAT) deficiency."
PMID:25518532
Alpha-1-antitrypsin deficiency in children: clinical characteristics and diagnosis.
1 finding
Alpha-1-antitrypsin deficiency (AATD) is a relatively rare and clinically very heterogeneous autosomal recessive disorder.
"Alpha-1-antitrypsin deficiency (AATD) is a relatively rare and clinically very heterogeneous autosomal recessive disorder."
PMID:26527439
Unusual Acute Sequelae of α1-Antitrypsin Deficiency: A Myriad of Symptoms With One Common Cure.
1 finding
Panniculitis associated with α1-antitrypsin deficiency (AATD) is well documented but rare.
"Panniculitis associated with α1-antitrypsin deficiency (AATD) is well documented but rare."
PMID:27296815
Alpha-1-antitrypsin (SERPINA1) mutation spectrum: Three novel variants and haplotype characterization of rare deficiency alleles identified in Portugal.
1 finding
Alpha-1-antitrypsin deficiency (AATD) is a genetic condition caused by SERPINA1 mutations, which culminates into lower protease inhibitor activity in the serum and predisposes affected individuals to emphysema.
"Alpha-1-antitrypsin deficiency (AATD) is a genetic condition caused by SERPINA1 mutations, which culminates into lower protease inhibitor activity in the serum and predisposes affected individuals to emphysema."
PMID:27465791
α1-Antitrypsin deficiency.
1 finding
α1-Antitrypsin deficiency (A1ATD) is an inherited disorder caused by mutations in SERPINA1, leading to liver and lung disease.
"α1-Antitrypsin deficiency (A1ATD) is an inherited disorder caused by mutations in SERPINA1, leading to liver and lung disease."
PMID:28058497
[A rare cause of severe panniculitis].
1 finding
A 58-year-old patient presented with a severe, episodic panniculitis of the upper legs.
"A 58-year-old patient presented with a severe, episodic panniculitis of the upper legs."
PMID:28073160
Activation of the c-Jun N-terminal kinase pathway aggravates proteotoxicity of hepatic mutant Z alpha1-antitrypsin.
1 finding
Alpha1-antitrypsin deficiency is a genetic disease that can affect both the lung and the liver.
"Alpha1-antitrypsin deficiency is a genetic disease that can affect both the lung and the liver."
PMID:28496314
Treatment of lung disease in alpha-1 antitrypsin deficiency: a systematic review.
1 finding
Alpha-1 antitrypsin deficiency (AATD) is a rare genetic condition predisposing individuals to chronic obstructive pulmonary disease (COPD).
"Alpha-1 antitrypsin deficiency (AATD) is a rare genetic condition predisposing individuals to chronic obstructive pulmonary disease (COPD)."
PMID:28927525
Alpha-1-antitrypsin deficiency: Genetic variations, clinical manifestations and therapeutic interventions.
1 finding
Alpha-1-antitrypsin (AAT) is an acute phase secretory glycoprotein that inhibits neutrophil proteases like elastase and is considered as the archetype of a family of structurally related serine-protease inhibitors termed serpins.
"Alpha-1-antitrypsin (AAT) is an acute phase secretory glycoprotein that inhibits neutrophil proteases like elastase and is considered as the archetype of a family of structurally related serine-protease inhibitors termed serpins."
PMID:29070580
COPD in individuals with the PiMZ alpha-1 antitrypsin genotype.
1 finding
COPD in individuals with the PiMZ alpha-1 antitrypsin genotype
"Since the discovery of severe alpha-1 antitrypsin deficiency as a genetic risk factor for emphysema, there has been ongoing debate over whether individuals with intermediate deficiency with one protease inhibitor Z allele (PiMZ, or MZ) are at some risk for emphysema."
PMID:29430176
Alpha 1 antitrypsin to treat lung disease in alpha 1 antitrypsin deficiency: recent developments and clinical implications.
1 finding
Reduced levels of AAT allow abnormal degradation of lung tissue, which may ultimately lead to the development of early-onset emphysema.
"Reduced levels of AAT allow abnormal degradation of lung tissue, which may ultimately lead to the development of early-onset emphysema."
PMID:29572094
Hepatic-targeted RNA interference provides robust and persistent knockdown of alpha-1 antitrypsin levels in ZZ patients.
1 finding
Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder causing pulmonary and liver disease.
"Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder causing pulmonary and liver disease."
PMID:30066494
Hepatopulmonary Syndrome in Children: A 20-Year Review of Presenting Symptoms, Clinical Progression, and Transplant Outcome.
1 finding
Hepatopulmonary syndrome (HPS) in stable patients with cirrhosis can easily be overlooked.
"Hepatopulmonary syndrome (HPS) in stable patients with cirrhosis can easily be overlooked."
PMID:31556146
Technique and outcome of domino liver transplantation from patients with maple syrup urine disease: Expanding the donor pool for live donor liver transplantation.
1 finding
Domino liver transplantation (DLT) using liver allografts from patients with metabolic disorders enhances organ utilization.
"Domino liver transplantation (DLT) using liver allografts from patients with metabolic disorders enhances organ utilization."
PMID:32062078
Does heart surgery change the capacity of α1-antitrypsin to inhibit the ATP-induced release of monocytic interleukin-1β? A preliminary study.
1 finding
Heart surgery involving cardiopulmonary bypass induces systemic inflammation that is, at least in part, caused by extracellular ATP originating from damaged cells and by proteases secreted by activated neutrophils.
"Heart surgery involving cardiopulmonary bypass induces systemic inflammation that is, at least in part, caused by extracellular ATP originating from damaged cells and by proteases secreted by activated neutrophils."
PMID:32621460
Why is Disease Penetration So Variable? Role of Genetic Modifiers of Lung Function in Alpha-1 Antitrypsin Deficiency.
1 finding
Individuals with alpha-1 antitrypsin deficiency (AATD) have marked heterogeneity in lung function, suspected to be related to a combination of both environmental (e.g., cigarette smoking) and genetic factors.
"Individuals with alpha-1 antitrypsin deficiency (AATD) have marked heterogeneity in lung function, suspected to be related to a combination of both environmental (e.g., cigarette smoking) and genetic factors."
PMID:32723872
CHOP and c-JUN up-regulate the mutant Z α(1)-antitrypsin, exacerbating its aggregation and liver proteotoxicity.
1 finding
α1-Antitrypsin (AAT) encoded by the SERPINA1 gene is an acute-phase protein synthesized in the liver and secreted into the circulation.
"α1-Antitrypsin (AAT) encoded by the SERPINA1 gene is an acute-phase protein synthesized in the liver and secreted into the circulation."
PMID:32726073
The Alpha-1 Antitrypsin Polymer Load Correlates With Hepatocyte Senescence, Fibrosis Stage and Liver-Related Mortality.
1 finding
Alpha-1 antitrypsin deficiency (AATD) is an important, inherited cause of chronic liver disease.
"Alpha-1 antitrypsin deficiency (AATD) is an important, inherited cause of chronic liver disease."
PMID:32911139
Clinical outcomes and survival following lung transplantation in patients with Alpha-1 antitrypsin deficiency.
1 finding
The primary intention of our study is to describe disease-specific outcomes in patients with alpha-1 antitrypsin deficiency (AATD) following lung transplantation (LT).
"The primary intention of our study is to describe disease-specific outcomes in patients with alpha-1 antitrypsin deficiency (AATD) following lung transplantation (LT)."
PMID:33139195
Long term results of liver transplantation for alpha-1 antitrypsin deficiency.
1 finding
Liver transplantation (LT) is the therapeutic option for end-stage liver disease associated with alpha1 antitrypsin (A1AT) deficiency.
"Liver transplantation (LT) is the therapeutic option for end-stage liver disease associated with alpha1 antitrypsin (A1AT) deficiency."
PMID:33239231
Hypothesis: Alpha-1-antitrypsin is a promising treatment option for COVID-19.
1 finding
No definitive treatment for COVID-19 exists although promising results have been reported with remdesivir and glucocorticoids.
"No definitive treatment for COVID-19 exists although promising results have been reported with remdesivir and glucocorticoids."
PMID:33649241
Up-regulation of miR-34b/c by JNK and FOXO3 protects from liver fibrosis.
1 finding
α1-Antitrypsin (AAT) deficiency is a common genetic disease presenting with lung and liver diseases.
"α1-Antitrypsin (AAT) deficiency is a common genetic disease presenting with lung and liver diseases."
PMID:35621045
The unfolded protein response to PI*Z alpha-1 antitrypsin in human hepatocellular and murine models.
1 finding
Alpha-1 antitrypsin (AAT) deficiency (AATD) is an inherited disease caused by mutations in the serpin family A member 1 (SERPINA1, also known as AAT) gene.
"Alpha-1 antitrypsin (AAT) deficiency (AATD) is an inherited disease caused by mutations in the serpin family A member 1 (SERPINA1, also known as AAT) gene."
PMID:35730566
Alu RNA induces NLRP3 expression through TLR7 activation in α-1-antitrypsin-deficient macrophages.
1 finding
α-1 antitrypsin (AAT) is a serine protease inhibitor that plays a pivotal role in maintaining lung homeostasis.
"α-1 antitrypsin (AAT) is a serine protease inhibitor that plays a pivotal role in maintaining lung homeostasis."
PMID:38294851
The p24-family and COPII subunit SEC24C facilitate the clearance of alpha1-antitrypsin Z from the endoplasmic reticulum to lysosomes.
1 finding
A subpopulation of the alpha-1-antitrypsin misfolding Z mutant (ATZ) is cleared from the endoplasmic reticulum (ER) via an ER-to-lysosome-associated degradation (ERLAD) pathway.
"A subpopulation of the alpha-1-antitrypsin misfolding Z mutant (ATZ) is cleared from the endoplasmic reticulum (ER) via an ER-to-lysosome-associated degradation (ERLAD) pathway."
PMID:38336172
Multiple Genes Core to ERAD, Macroautophagy and Lysosomal Degradation Pathways Participate in the Proteostasis Response in α1-Antitrypsin Deficiency.
1 finding
In the classic form of α1-antitrypsin deficiency (ATD), the misfolded α1-antitrypsin Z (ATZ) variant accumulates in the endoplasmic reticulum (ER) of liver cells.
"In the classic form of α1-antitrypsin deficiency (ATD), the misfolded α1-antitrypsin Z (ATZ) variant accumulates in the endoplasmic reticulum (ER) of liver cells."
PMID:38599244
Pulmonary manifestations of alpha 1 antitrypsin deficiency.
1 finding
Alpha 1 antitrypsin deficiency is a widely under recognized autosomal codominant condition caused by genetic mutations in the SERPINA 1 gene, which encodes for alpha 1 antitrypsin (AAT), a serine protease inhibitor.
"Alpha 1 antitrypsin deficiency is a widely under recognized autosomal codominant condition caused by genetic mutations in the SERPINA 1 gene, which encodes for alpha 1 antitrypsin (AAT), a serine protease inhibitor."
PMID:38992821
Differences in bile acid profiles between cholestatic diseases - Development of a high throughput assay for dried bloodspots.
1 finding
Cholestasis causes accumulation of bile acids (BAs) and changes the circulating bile acid profile.
"Cholestasis causes accumulation of bile acids (BAs) and changes the circulating bile acid profile."
PMID:40378984
Insulin-like Growth Factor-1 Reflects Liver Disease Stage and Improves Prediction of Liver-related Mortality.
1 finding
Liver-related mortality represents a growing public health concern, disproportionately affecting younger subjects.
"Liver-related mortality represents a growing public health concern, disproportionately affecting younger subjects."
PMID:40550287
Sleep apnea among individuals with Alpha-1 antitrypsin deficiency-associated lung disease.
1 finding
Alpha-1 antitrypsin deficiency (AATD) is a genetic condition that has high rates of associated COPD.
"Alpha-1 antitrypsin deficiency (AATD) is a genetic condition that has high rates of associated COPD."
PMID:40563447
Alpha-1 Antitrypsin Deficiency and Bronchial Asthma: Current Challenges.
1 finding
Alpha-1 antitrypsin deficiency (AATD) is a rare genetic condition classically associated with pulmonary emphysema and liver disease.
"Alpha-1 antitrypsin deficiency (AATD) is a rare genetic condition classically associated with pulmonary emphysema and liver disease."
PMID:40665347
Assessing inflammatory protein biomarkers in COPD subjects with and without alpha-1 antitrypsin deficiency.
1 finding
Individuals homozygous for the Alpha-1 Antitrypsin (AAT) Z allele (Pi*ZZ) exhibit heterogeneity in COPD risk.
"Individuals homozygous for the Alpha-1 Antitrypsin (AAT) Z allele (Pi*ZZ) exhibit heterogeneity in COPD risk."
PMID:40888606
Increased Risk of Cholesteatoma in Individuals With Alpha-1 Antitrypsin Deficiency: A Cohort Study.
1 finding
To estimate the risk of cholesteatoma in patients with alpha-1 antitrypsin deficiency (AATD) compared to the general population using time-to-event analysis.
"To estimate the risk of cholesteatoma in patients with alpha-1 antitrypsin deficiency (AATD) compared to the general population using time-to-event analysis."
PMID:40967767
Two randomised controlled phase 2 studies of the oral neutrophil elastase inhibitor alvelestat in alpha-1 antitrypsin deficiency.
1 finding
Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder that causes emphysema from lack of the alpha-1 antitrypsin (AAT) serpin antiprotease, leading to protease-antiprotease imbalance.
"Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder that causes emphysema from lack of the alpha-1 antitrypsin (AAT) serpin antiprotease, leading to protease-antiprotease imbalance."
PMID:41216004
The Epidemiology of Alpha-1 Antitrypsin Deficiency in Norway.
1 finding
Alpha-1 antitrypsin deficiency (AATD) is a genetic condition characterized by insufficient levels of alpha-1 antitrypsin and elevated risk of lung and liver disease.
"Alpha-1 antitrypsin deficiency (AATD) is a genetic condition characterized by insufficient levels of alpha-1 antitrypsin and elevated risk of lung and liver disease."
PMID:41364209
Quantitative CT of emphysema, wall thickness and mucus plugs in alpha-1-antitrypsin deficiency: relationship to clinical outcomes.
1 finding
Alpha-1-antitrypsin deficiency (AATD) is a rare genetic disorder leading to chronic obstructive pulmonary disease (COPD).
"Alpha-1-antitrypsin deficiency (AATD) is a rare genetic disorder leading to chronic obstructive pulmonary disease (COPD)."
PMID:41789803
Novel mutation (M(angera)-E288V) in alpha-1 antitrypsin deficiency.
1 finding
Alpha-1 antitrypsin deficiency is an autosomal, codominant disorder caused by mutations of the SERPINA1 gene.
"Alpha-1 antitrypsin deficiency is an autosomal, codominant disorder caused by mutations of the SERPINA1 gene."
PMID:41791905
Prevalence of liver disease and liver transplantation in pediatric ZZ alpha-1 antitrypsin deficiency: A systematic review and meta-analysis.
1 finding
Pediatric Pi*ZZ alpha-1 antitrypsin deficiency (A1ATD) can cause hepatocyte A1AT polymer retention and progressive liver injury, but estimates of childhood liver morbidity vary across studies and remain poorly defined.
"Pediatric Pi*ZZ alpha-1 antitrypsin deficiency (A1ATD) can cause hepatocyte A1AT polymer retention and progressive liver injury, but estimates of childhood liver morbidity vary across studies and remain poorly defined."
PMID:41883848
Decalogue of Best Practices in Alpha-1 Antitrypsin Deficiency.
1 finding
Alpha-1 antitrypsin (AAT) deficiency is an underdiagnosed genetic disorder that predisposes individuals to the development of pulmonary emphysema and liver disease.
"Alpha-1 antitrypsin (AAT) deficiency is an underdiagnosed genetic disorder that predisposes individuals to the development of pulmonary emphysema and liver disease."
PMID:42072628
Adaptive Regulation of mTOR Activity by AMPK, Akt, and ATF6 Pathways in Pi*Z Alpha-1 Antitrypsin Deficient Hepatocytes.
1 finding
Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder characterized by intracellular retention of mutant Z (Pi*Z) alpha-1 antitrypsin (AAT) within hepatocytes, resulting in progressive liver disease.
"Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder characterized by intracellular retention of mutant Z (Pi*Z) alpha-1 antitrypsin (AAT) within hepatocytes, resulting in progressive liver disease."
PMID:8578172
Prognosis and life expectancy on alpha-1-antitrypsin deficiency and chronic liver disease.
1 finding
Alpha-1-antitrypsin deficiency is a common autosomal recessive disorder associated with early development of emphysema, liver cirrhosis, and hepatocellular carcinoma.
"Alpha-1-antitrypsin deficiency is a common autosomal recessive disorder associated with early development of emphysema, liver cirrhosis, and hepatocellular carcinoma."
PMID:28752441
Pathophysiology of Alpha-1 Antitrypsin Deficiency Liver Disease.
No top-level findings curated for this source.
PMID:40943425
Next-Generation Regenerative Therapies for Alpha-1 Antitrypsin Deficiency: Molecular Pathogenesis to Clinical Translation.
No top-level findings curated for this source.
PMID:42075511
Alpha-1 Antitrypsin Deficiency-Associated Chronic Obstructive Pulmonary Disease.
No top-level findings curated for this source.

Deep Research

2
Falcon ▸
Disease Characteristics Research Template
Edison Scientific Literature 31 citations 2026-04-25T16:50:11.448472

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

  • Disease Name: Alpha-1 Antitrypsin Deficiency
  • MONDO ID: (if available)
  • Category: Mendelian

Research Objectives

Please provide a comprehensive research report on Alpha-1 Antitrypsin Deficiency covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

  • What is the disease? Provide a concise overview.
  • What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
  • What are the common synonyms and alternative names?
  • Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

  • Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
  • Risk Factors:

    Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases

  • Genetic risk factors (causal variants, susceptibility loci, modifier genes)
  • Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
  • Protective Factors:

    Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases

  • Genetic protective factors (protective variants, modifier alleles)
  • Environmental protective factors (diet, lifestyle, exposures that reduce risk)
  • Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

    Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

  • Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

    Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene

  • Pathogenic Variants:
  • Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
  • Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
  • Variant type/class (missense, frameshift, nonsense, splice-site, structural)
  • Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
  • Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
  • Functional consequences (loss of function, gain of function, dominant negative)
  • Modifier Genes: Genes that modify disease severity or expression
  • Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

    Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

  • Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

    Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases

  • Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

    Search first: CDC databases, WHO, PubMed, NHANES

  • Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

    Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

  • Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

    Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc

  • Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

    Search first: Gene Ontology (GO), Reactome, KEGG, PubMed

  • Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

    Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold

  • Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

    Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA

  • Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

    Search first: ImmPort, Immunome Database, IEDB, Gene Ontology

  • Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

    Search first: PubMed, Gene Ontology, Reactome

  • Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

    Search first: BRENDA, UniProt, KEGG, OMIM, PubMed

  • Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Molecular Profiling (if available):
  • Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
  • Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
  • Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
  • Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
  • Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
  • Advanced Technologies (if applicable):
  • Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
  • Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
  • Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
  • Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

  • Organ Level:
  • Primary organs directly affected
  • Secondary organ involvement (complications, secondary effects)
  • Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

    Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT

  • Tissue and Cell Level:
  • Specific tissue types affected (epithelial, connective, muscle, nervous)
  • Specific cell populations targeted (with Cell Ontology terms)

    Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB

  • Subcellular Level:
  • Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

    Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas

  • Localization:
  • Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
  • Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

  • Onset:
  • Typical age of onset (congenital, pediatric, adult, geriatric)
  • Onset pattern (acute, subacute, chronic, insidious)

    Search first: OMIM, Orphanet, HPO, PubMed

  • Progression:
  • Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
  • Progression rate (rapid, slow, variable)
  • Disease course pattern (episodic, relapsing-remitting, progressive, stable)
  • Disease duration (self-limited, chronic lifelong)

    Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM

  • Patterns:
  • Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
  • Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

  • Epidemiology:
  • Prevalence (cases per 100,000 at given time)
  • Incidence (new cases per 100,000 per year)

    Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries

  • For Genetic Etiology:
  • Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
  • Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
  • Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
  • Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
  • Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
  • Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
  • Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
  • Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
  • Population Demographics:
  • Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
  • Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
  • Geographic distribution of specific variants
  • Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
  • Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

  • Clinical Tests:
  • Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
  • Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
  • Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
  • Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
  • Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
  • Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
  • Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
  • Genetic Testing:

    Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen

  • Overview of recommended genetic testing approach
  • Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
  • Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
  • Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
  • Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
  • Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
  • Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
  • FISH > Search first: ClinVar, cytogenetics databases, PubMed
  • Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
  • Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
  • Omics-Based Diagnostics (if applicable):
  • RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
  • Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
  • Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
  • Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
  • Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
  • Clinical Criteria:
  • Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
  • Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
  • Screening:
  • Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

  • Survival and Mortality:
  • Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
  • Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
  • Mortality rate > Search first: CDC, WHO, GBD, national mortality databases
  • Disease-specific mortality (deaths directly attributable to disease) > Search first: Disease registries, CDC Wonder, GBD, PubMed
  • Morbidity and Function:
  • Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
  • Disability outcomes (long-term functional impairments) > Search first: ICF (International Classification of Functioning), disability registries
  • Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
  • Disease Course:
  • Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
  • Recovery potential (likelihood and extent of recovery, with vs without treatment) > Search first: Natural history studies, rehabilitation databases, PubMed
  • Prediction:
  • Prognostic factors (age, disease severity, biomarkers, treatment response) > Search first: Prognostic models databases, clinical calculators, PubMed
  • Prognostic biomarkers (molecular markers predicting disease course) > Search first: FDA Biomarker database, PubMed, cancer prognostic databases

12. Treatment

  • Pharmacotherapy:
  • Pharmacological treatments (drug names, drug classes, mechanisms of action) > Search first: DrugBank, RxNorm, ATC classification, DailyMed, FDA databases
  • Pharmacogenomics (how genetic variants affect drug metabolism, efficacy, toxicity) > Search first: PharmGKB, CPIC (Clinical Pharmacogenetics), FDA Table of PGx Biomarkers
  • Advanced Therapeutics:
  • Gene therapy (viral vectors, CRISPR, gene replacement, gene editing) > Search first: ClinicalTrials.gov, FDA gene therapy database, ASGCT resources
  • Cell therapy (stem cell transplant, CAR-T, cellular therapeutics) > Search first: ClinicalTrials.gov, FDA cell therapy database, FACT standards
  • RNA-based therapies (ASOs, siRNA, mRNA therapies) > Search first: ClinicalTrials.gov, FDA approvals, PubMed
  • Targeted therapies (treatments directed at specific molecular targets) > Search first: My Cancer Genome, OncoKB, ClinicalTrials.gov, FDA approvals
  • Immunotherapies (checkpoint inhibitors, monoclonal antibodies) > Search first: Cancer Immunotherapy Database, FDA approvals, ClinicalTrials.gov
  • Surgical and Interventional:
  • Surgical interventions (types of surgery, timing, outcomes) > Search first: CPT codes, surgical registries, clinical guidelines, PubMed
  • Supportive and Rehabilitative:
  • Supportive care (symptom management, pain control, nutrition) > Search first: Clinical guidelines, Cochrane Library, PubMed
  • Rehabilitation (physical therapy, occupational therapy, speech therapy) > Search first: Rehabilitation medicine databases, clinical guidelines, PubMed
  • Experimental:
  • Experimental treatments in clinical trials (with NCT identifiers if available) > Search first: ClinicalTrials.gov, EU Clinical Trials Register, WHO ICTRP
  • Treatment Outcomes:
  • Treatment response rates > Search first: Clinical trial databases, FDA reviews, systematic reviews, PubMed
  • Side effects and adverse events > Search first: FDA Adverse Event Reporting System (FAERS), MedWatch, PubMed
  • Treatment Strategy:
  • Treatment algorithms (clinical pathways, decision trees) > Search first: Clinical practice guidelines, NCCN Guidelines, UpToDate
  • Combination therapies > Search first: ClinicalTrials.gov, treatment guidelines, PubMed
  • Personalized medicine approaches (genotype-guided treatment) > Search first: My Cancer Genome, CIViC, PharmGKB, precision medicine databases

For each treatment, suggest MAXO (Medical Action Ontology) terms where applicable.

13. Prevention

  • Prevention Levels:
  • Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
  • Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
  • Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
  • Immunization: Vaccine strategies (if applicable)

    Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database

  • Screening and Early Detection:
  • Screening programs (population-based: newborn screening, cancer screening) > Search first: CDC screening programs, USPSTF, cancer screening databases
  • Genetic screening (carrier screening, preimplantation genetic diagnosis, prenatal testing) > Search first: ACMG recommendations, ACOG guidelines, GTR
  • Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
  • Behavioral Interventions: Lifestyle modifications to reduce risk

    Search first: CDC, WHO, behavioral intervention databases, Cochrane Library

  • Counseling: Genetic counseling (risk assessment, family planning guidance)

    Search first: NSGC resources, ACMG guidelines, GeneReviews

  • Public Health:
  • Public health interventions (sanitation, vector control, health education) > Search first: CDC, WHO, public health databases, PubMed
  • Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
  • Prophylaxis: Preventive medications or procedures

    Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

  • Taxonomy: Species affected (with NCBI Taxon identifiers)

    Search first: NCBI Taxonomy

  • Breed: Specific breeds affected (with VBO identifiers if applicable)

    Search first: VBO (Vertebrate Breed Ontology)

  • Gene: Orthologous genes in other species (with NCBI Gene IDs)

    Search first: NCBI Gene

  • Natural Disease:
  • Naturally occurring disease in other species (companion animals, wildlife) > Search first: OMIA (Online Mendelian Inheritance in Animals), VetCompass, PubMed
  • Veterinary relevance and importance in animal health > Search first: OMIA, veterinary databases, PubMed
  • Comparative Biology:
  • Comparative pathology (similarities and differences across species) > Search first: OMIA, comparative pathology databases, PubMed
  • Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
  • Transmission (if applicable):
  • Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
  • Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

  • Model Types:
  • Model organism type (mammalian, invertebrate, cellular, in vitro) > Search first: Alliance of Genome Resources, model organism databases
  • Specific model systems (mouse, rat, zebrafish, Drosophila, C. elegans, yeast, cell lines, organoids, iPSCs) > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, SGD, ATCC, Cellosaurus
  • Induced models (drug treatment, surgical intervention, environmental manipulation) > Search first: MGI, model organism databases, PubMed
  • Genetic Models:
  • Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
  • Model Characteristics:
  • Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
  • Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
  • Applications:
  • Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
  • Resources:
  • Model databases > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, IMSR, EMMA, MMRRC

Citation Requirements

  • Cite primary literature (PMID preferred) for all mechanistic and clinical claims
  • Prioritize recent reviews and landmark papers
  • Include direct quotes from abstracts where possible to support key statements
  • Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, MAXO, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (MAXO terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

Alpha-1 Antitrypsin Deficiency (AATD) — Disease Characteristics Research Report (Mendelian)

Target disease

  • Disease name: Alpha-1 Antitrypsin Deficiency (AATD) (also written alpha 1-antitrypsin deficiency) (feitosa12024recommendationsforthe pages 1-2)
  • Category: Mendelian / inborn error of protein homeostasis (SERPIN misfolding) (feitosa12024recommendationsforthe pages 2-3, mohammad2024livercharacterizationof pages 1-2)
  • MONDO ID: MONDO:0013282 (“alpha 1-antitrypsin deficiency”) from Open Targets disease mapping (feitosa12024recommendationsforthe pages 1-2)

Evidence note (scope/limitations)

This report is based on the retrieved full-text excerpts and ClinicalTrials.gov records in the current tool state. Some requested identifiers (e.g., OMIM, Orphanet, ICD-10/ICD-11, MeSH) could not be confirmed from the retrieved excerpts and therefore are not asserted here.

1. Disease information

1.1 Concise overview / definition

AATD is a relatively rare genetic disorder with autosomal codominant inheritance that leads to reduced serum alpha-1 antitrypsin (AAT) and consequently reduced anti-elastase activity in the lung, increasing risk for pulmonary emphysema/COPD and also predisposing to liver disease (fibrosis/cirrhosis) due to intracellular accumulation of misfolded AAT in hepatocytes (feitosa12024recommendationsforthe pages 1-2, feitosa12024recommendationsforthe pages 2-3, mohammad2024livercharacterizationof pages 1-2). In addition to lung and liver disease, AATD can present with extra-pulmonary manifestations including necrotizing panniculitis and vasculitis (feitosa12024recommendationsforthe pages 1-2, feitosa2023diagnosisandaugmentation pages 1-2, fouka2026alpha1antitrypsindeficiencyassociated pages 1-2).

1.2 Key identifiers (available in retrieved evidence)

  • MONDO: MONDO:0013282 (Open Targets mapping) (feitosa12024recommendationsforthe pages 1-2)
  • Disease gene (HGNC symbol): SERPINA1 (feitosa12024recommendationsforthe pages 1-2, feitosa12024recommendationsforthe pages 2-3)
  • Chromosomal location (gene): 14q32.1 for SERPINA1 (feitosa12024recommendationsforthe pages 1-2)
  • ClinicalTrials.gov registry for natural history: EARCO registry (NCT04180319) (NCT04180319 chunk 1)

1.3 Synonyms / alternative names

  • Alpha-1-antitrypsin deficiency; AAT deficiency; AATD; Alpha1-proteinase inhibitor (A1PI) deficiency (in context of augmentation therapy) (feitosa2023diagnosisandaugmentation pages 4-5, miravitlles2023ninecontroversialquestions pages 2-3).

1.4 Evidence source type

The current synthesis draws primarily from aggregated disease-level resources (guideline/review articles) and registries/trials, not EHR-derived single-patient case data (feitosa12024recommendationsforthe pages 1-2, NCT04180319 chunk 1, miravitlles2023ninecontroversialquestions pages 2-3).

2. Etiology

2.1 Disease causal factors

Primary cause: inherited pathogenic variants in SERPINA1 that reduce circulating AAT levels and/or produce dysfunctional AAT (loss of antiprotease function), and (for Z-type variants) promote misfolding/polymerization with hepatocellular retention (gain-of-toxic-function in liver) (feitosa12024recommendationsforthe pages 2-3, mohammad2024livercharacterizationof pages 1-2).

2.2 Risk factors

Genetic risk

  • Severe deficiency genotypes (e.g., Pi*ZZ; null variants) are strongly associated with emphysema and liver disease risk (feitosa12024recommendationsforthe pages 2-3, feitosa12024recommendationsforthe pages 1-2).
  • Heterozygotes (e.g., PiMZ, PiSZ) can have increased lung disease risk that is highly contingent on exposures, particularly smoking (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2, fouka2026alpha1antitrypsindeficiencyassociated pages 2-4).

Environmental/lifestyle risk

  • Cigarette smoking is a major modifier that accelerates emphysema progression and increases risk even for some heterozygotes; smoking oxidatively inactivates AAT and amplifies neutrophilic inflammation, worsening protease–antiprotease imbalance (fouka2026alpha1antitrypsindeficiencyassociated pages 2-4, turner2025advancingtheunderstanding pages 1-3).
  • Broader environmental exposures are recognized modifiers interacting with genotype in determining emphysema risk (feitosa12024recommendationsforthe pages 1-2).

Gene–environment interactions (GxE)

A 2024 expert commentary highlights that Pi*MZ heterozygotes have a ~5–10× increased COPD risk if they smoke, whereas Pi*MZ never-smokers have risk similar to Pi*MM never-smokers, illustrating a strong gene–smoking interaction (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2). Similar “nuanced risk” patterns are described for Pi*SZ individuals (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2).

2.3 Protective factors

  • Never smoking / smoking cessation is strongly protective against development/progression of AATD-associated emphysema; early genetic diagnosis can facilitate smoking cessation and prevention-oriented counseling (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2).

3. Phenotypes (clinical spectrum)

3.1 Core pulmonary phenotypes

  • Emphysema / COPD: classically earlier-onset emphysema (often before age 50) with heterogeneity in lobar patterns; protease–antiprotease imbalance drives progressive tissue destruction (fouka2026alpha1antitrypsindeficiencyassociated pages 1-2, fouka2026alpha1antitrypsindeficiencyassociated pages 2-4).
  • Bronchiectasis and airway-predominant disease: AATD-related COPD can include airway-predominant disease, small airways dysfunction, chronic bronchitis, and bronchiectasis (fouka2026alpha1antitrypsindeficiencyassociated pages 1-2).
  • Asthma-like disease / late-onset asthma: evaluation is recommended in some late-onset asthma contexts (feitosa12024recommendationsforthe pages 1-2).

Suggested HPO terms (examples): - Emphysema HP:0002097 - Chronic obstructive pulmonary disease HP:0006510 - Bronchiectasis HP:0002110 - Reduced forced expiratory volume in 1 second HP:0030440 - Reduced diffusing capacity of the lungs for carbon monoxide (DLCO) HP:0045051

3.2 Hepatic phenotypes

  • Liver fibrosis/cirrhosis from hepatocyte retention of misfolded/polymerized AAT; associated with hepatocellular damage and increased hepatocellular carcinoma risk (feitosa12024recommendationsforthe pages 2-3, mohammad2024livercharacterizationof pages 1-2).
  • Transcriptomic evidence from a 2024 cohort study: livers of AATD individuals with COPD showed upregulation of pathways for fibrosis, extracellular matrix remodeling, collagen deposition, hepatocellular damage, and inflammation, with histologic evidence of higher fibrosis and injury (mohammad2024livercharacterizationof pages 1-2).

Suggested HPO terms (examples): - Hepatic fibrosis HP:0001395 - Cirrhosis HP:0001394 - Elevated transaminases HP:0002910

3.3 Skin/immune and other systemic phenotypes

  • Necrotizing panniculitis is a recognized manifestation and may be an indication for augmentation therapy in expert guidance (feitosa12024recommendationsforthe pages 1-2, turner2025advancingtheunderstanding pages 1-3).
  • Systemic vasculitis (including granulomatosis with polyangiitis contexts) has been reported/recognized in the phenotype spectrum (feitosa12024recommendationsforthe pages 1-2).

Suggested HPO terms (examples): - Panniculitis HP:0001032 - Vasculitis HP:0002633

3.4 Quality-of-life impact

A 2023 cohort comparison found that health status (SGRQ) deteriorated faster in augmentation-naïve severe AATD: annual SGRQ deterioration 1.43 points/year greater in controls versus augmented patients (95% CI 0.47–2.39; p=0.003), indicating meaningful QoL burden and potential modification by therapy (ellis2023qualityoflife pages 1-2).

4. Genetic / molecular information

4.1 Causal gene

  • SERPINA1 (serpin family A member 1) encodes AAT, a serine protease inhibitor (feitosa12024recommendationsforthe pages 2-3, mazzuca2024immunologicalandhomeostatic pages 1-2).

4.2 Pathogenic variants (common)

  • Z variant: described as a glutamic acid→lysine substitution (position 342) that produces a misfolded protein prone to polymerization and hepatocyte retention, with severe deficiency (feitosa12024recommendationsforthe pages 2-3, feitosa12024recommendationsforthe pages 1-2).
  • S variant: common deficiency allele frequently paired with Z in compound heterozygosity (feitosa2023diagnosisandaugmentation pages 1-2, ferrarotti2024rarevariantsin pages 1-2).

Variant nomenclature from a 2024 systematic review of rare variants: - Z: c.1096G>A; p.Glu366Lys - S: c.863A>T; p.Glu288Val (ferrarotti2024rarevariantsin pages 1-2)

(Notes: other sources in this tool state describe Z as Glu342Lys; the discrepancy likely reflects different protein numbering conventions, but both refer to the canonical Z-deficiency allele; the report preserves the exact forms as stated in the cited sources.) (feitosa12024recommendationsforthe pages 2-3, ferrarotti2024rarevariantsin pages 1-2)

4.3 Variant classes and functional consequences

  • Loss-of-function in lung: reduced circulating functional AAT removes inhibition of neutrophil elastase (NE) and related proteases (loss of antiprotease protection) (mazzuca2024immunologicalandhomeostatic pages 1-2, turner2025advancingtheunderstanding pages 1-3).
  • Gain-of-toxic-function in liver: Z-AAT misfolding/polymerization causes ER retention and proteotoxic stress in hepatocytes (feitosa12024recommendationsforthe pages 2-3, mohammad2024livercharacterizationof pages 1-2).

4.4 Allele frequency / population distribution (selected)

  • Normal M allele frequency: ~85–90% (feitosa12024recommendationsforthe pages 2-3).
  • Example large DTC-genotyped cohort distribution (reported in a 2025 review): PIMM 58.1%, PIMS 28.3%, PIMZ 12.1%, PISZ 0.6%, PI*ZZ 0.2% (yang2025nextgenerationregenerativetherapies pages 2-4).
  • Z allele carrier frequency estimate: “~1 in 25 people of European ancestry” (feitosa12024recommendationsforthe pages 2-3).

4.5 Modifier genetics / epigenetics

  • A 2024 guideline notes that “other genetic factors” interact with genotype and exposures to influence emphysema risk (feitosa12024recommendationsforthe pages 1-2).
  • AATD registries include an “Epigenetic regulation of immunity” observational study (NCT02691611; retrieved but not expanded here), indicating active research interest; mechanistic epigenetic conclusions were not extractable from the currently retrieved excerpts.

5. Mechanism / pathophysiology

5.1 Lung disease causal chain (current model)

1) SERPINA1 deficiency/dysfunction → reduced functional AAT in blood and airway lining fluid (mazzuca2024immunologicalandhomeostatic pages 1-2, turner2025advancingtheunderstanding pages 1-3). 2) Protease–antiprotease imbalance: unopposed neutrophil elastase degrades lung elastin and extracellular matrix, driving emphysema progression (turner2025advancingtheunderstanding pages 1-3, yang2025nextgenerationregenerativetherapies pages 5-7). 3) Inflammation amplification: neutrophil proteases can activate inflammatory mediators; NETosis and cytokines (e.g., TNF-α, IL-6) contribute to sustained inflammation and recruitment (yang2025nextgenerationregenerativetherapies pages 5-7, yang2025nextgenerationregenerativetherapies pages 9-10). 4) Exposure interaction: smoking worsens oxidant stress and can impair AAT function, accelerating tissue destruction (fouka2026alpha1antitrypsindeficiencyassociated pages 2-4, turner2025advancingtheunderstanding pages 1-3).

Relevant targets/pathways: - ELANE (neutrophil elastase) is a key mechanistic effector of lung damage in AATD and appears in disease–target associations (Open Targets) (feitosa12024recommendationsforthe pages 1-2).

Suggested GO biological process terms (examples): - Neutrophil degranulation (GO:0043312) - Inflammatory response (GO:0006954) - Extracellular matrix disassembly (GO:0022617) - Proteolysis (GO:0006508)

Suggested CL cell types (examples): - Neutrophil (CL:0000775) - Alveolar macrophage (CL:0000583) - Alveolar type II pneumocyte (CL:0002063) (AEC2 implicated in inflammatory/UPR signatures in mechanistic reviews) (yang2025nextgenerationregenerativetherapies pages 4-5)

Anatomical/UBERON: lung (UBERON:0002048), alveolus (UBERON:0002299), small airway (UBERON:0002185).

5.2 Liver disease causal chain (current model)

1) Z-AAT misfolding → polymerization/aggregation and retention in hepatocyte ER (feitosa12024recommendationsforthe pages 2-3, mohammad2024livercharacterizationof pages 1-2). 2) Proteotoxic stress and perturbed proteostasis (ERAD/autophagy/proteasome handling) → ER stress/UPR-related signaling and inflammatory pathway activation (NF-κB, MAPK; JNK/CHOP-mediated injury described in mechanistic reviews) (yang2025nextgenerationregenerativetherapies pages 5-7). 3) Downstream consequences: hepatocellular injury, ECM remodeling/collagen deposition, progression to fibrosis/cirrhosis; risk is heterogeneous and may be worsened by systemic inflammation associated with COPD (mohammad2024livercharacterizationof pages 1-2).

Suggested GO processes: - Response to endoplasmic reticulum stress (GO:0034976) - Unfolded protein response (GO:0030968) - Autophagy (GO:0006914) - Collagen fibril organization (GO:0030199)

Suggested cellular component (GO-CC): endoplasmic reticulum lumen (GO:0005788); endoplasmic reticulum (GO:0005783).

6. Environmental information

6.1 Environmental/lifestyle modifiers

  • Smoking is the dominant modifiable exposure: increases risk and accelerates progression of emphysema; can oxidatively impair AAT and intensify neutrophilic airway inflammation (fouka2026alpha1antitrypsindeficiencyassociated pages 2-4, turner2025advancingtheunderstanding pages 1-3).
  • Passive smoke exposure, poverty, and structural inequities contribute to underdiagnosis and outcomes disparities in AATD-related lung disease (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2).

6.2 Infectious agents

No specific pathogen is a primary cause; infections are clinically relevant as exacerbation triggers in COPD. Observational reports describe reductions in infections/exacerbations after augmentation therapy initiation in some cohorts (mazzuca2024immunologicalandhomeostatic pages 9-10).

7. Anatomical structures affected

7.1 Organ level (primary)

  • Lung: emphysema/COPD, bronchiectasis, small airway disease (fouka2026alpha1antitrypsindeficiencyassociated pages 1-2, fouka2026alpha1antitrypsindeficiencyassociated pages 2-4).
  • Liver: fibrosis/cirrhosis, hepatocellular damage and cancer risk (mohammad2024livercharacterizationof pages 1-2).

7.2 Tissue/cell level

  • Lung parenchyma elastin and interstitium; immune infiltrates dominated by neutrophils and macrophages (turner2025advancingtheunderstanding pages 1-3, yang2025nextgenerationregenerativetherapies pages 9-10).
  • Hepatocytes as primary site of Z-AAT accumulation and fibrosis-related pathways (mohammad2024livercharacterizationof pages 1-2).

7.3 Subcellular

  • Endoplasmic reticulum (ER retention of Z-AAT polymers) (feitosa12024recommendationsforthe pages 2-3, yang2025nextgenerationregenerativetherapies pages 5-7).

8. Temporal development (onset and progression)

  • Onset: AATD is genetic (present from birth), but clinical presentation is variable and often adult-onset for lung disease; liver disease can appear in childhood and/or adulthood (biphasic pattern described in mechanistic review) (yang2025nextgenerationregenerativetherapies pages 2-4).
  • Progression: lung disease is typically progressive; CT densitometry is described as a sensitive indicator of emphysema progression (feitosa12024recommendationsforthe pages 1-2, miravitlles2023ninecontroversialquestions pages 2-3).

9. Inheritance and population

9.1 Inheritance pattern

  • Autosomal codominant inheritance is repeatedly stated (feitosa12024recommendationsforthe pages 1-2, feitosa2023diagnosisandaugmentation pages 1-2).

9.2 Epidemiology (selected recent quantitative estimates)

  • Global burden: >3 million people worldwide estimated to have allele combinations associated with severe AATD (feitosa12024recommendationsforthe pages 1-2, feitosa12024recommendationsforthe pages 2-3).
  • Underdiagnosis: “only ~10% diagnosed” is suggested in a 2024 guideline (feitosa12024recommendationsforthe pages 1-2); <10% identified is also stated in a 2026 review (fouka2026alpha1antitrypsindeficiencyassociated pages 1-2).
  • Pi*ZZ prevalence estimates:
  • ~1:2,000–5,000 in Europe; ~1:5,000–7,000 in countries with substantial European immigration (feitosa12024recommendationsforthe pages 2-3).
  • ~1 in 3,000–5,000 in people of European descent (miravitlles2023ninecontroversialquestions pages 1-2).
  • AATD contribution to COPD/emphysema: ~1% of COPD and up to 2% of emphysema (fouka2026alpha1antitrypsindeficiencyassociated pages 1-2).
  • Registry scale: EARCO plans ~3,000 participants across >25 countries over 5 years and tracks FEV1, QoL, and mortality longitudinally (NCT04180319) (NCT04180319 chunk 1).

10. Diagnostics

10.1 Clinical tests and biomarkers

  • Serum AAT concentration is the first-line quantitative test, followed by phenotyping and/or genotyping to identify allelic variants (feitosa12024recommendationsforthe pages 1-2).
  • Typical normal serum AAT (Pi*MM): 100–220 mg/dL (guideline) (feitosa12024recommendationsforthe pages 2-3).
  • Severe deficiency threshold used for specific therapy eligibility: <57 mg/dL or <11 µM (feitosa12024recommendationsforthe pages 1-2).

10.2 Functional and imaging tests

  • Spirometry monitoring is emphasized, but CT lung densitometry is considered the most sensitive measure of emphysema progression (not recommended for routine monitoring in some guidance) (feitosa12024recommendationsforthe pages 1-2, miravitlles2023ninecontroversialquestions pages 2-3).

10.3 Screening and case-finding

  • Major societies recommend testing high-risk groups (e.g., COPD, unexplained liver disease, panniculitis, vasculitis), and a 2024 ATS editorial emphasizes that the U.S. lacks newborn or generalized later-life screening for AATD and argues for population/targeted/family-based screening to reduce inequities (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2).

Diagnostic algorithm (visual evidence): a guideline diagnostic pathway figure was retrieved (feitosa12024recommendationsforthe media f6c82200).

11. Outcome / prognosis

11.1 Mortality and QoL outcomes (recent observational comparison)

A 2023 analysis of prospectively followed cohorts found: - Mean annual SGRQ deterioration: 1.43 points/year worse in augmentation-naïve controls vs augmented patients (95% CI 0.47–2.39; p=0.003). - 7-year median survival: 82.7% controls vs 87.8% augmented (p=0.66; not statistically significant) (ellis2023qualityoflife pages 1-2, ellis2023qualityoflife pages 3-4).

11.2 Prognostic factors

  • Smoking status is a dominant prognostic modifier (accelerates emphysema; alters risk in heterozygotes) (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2, fouka2026alpha1antitrypsindeficiencyassociated pages 2-4).
  • Disease heterogeneity complicates individual prognosis prediction, motivating registry-based prognostic tools (NCT04180319 chunk 1, miravitlles2023ninecontroversialquestions pages 2-3).

12. Treatment

12.1 Disease-specific pharmacotherapy: IV augmentation therapy (A1PI)

Definition and core claims: IV augmentation therapy is described as the only specific disease-modifying therapy for AATD-associated emphysema (miravitlles2023ninecontroversialquestions pages 1-2).

Eligibility and thresholds: generally for severe deficiency (often requiring serum AAT <11 µM or ~50–57 mg/dL) with emphysema and non-smoking status (feitosa12024recommendationsforthe pages 1-2, miravitlles2023ninecontroversialquestions pages 2-3).

Dosing (common): weekly IV 60 mg/kg is the standard regimen; alternative regimens have been explored but may provide less consistent time above protective thresholds (feitosa2023diagnosisandaugmentation pages 2-4, feitosa2023diagnosisandaugmentation pages 4-5).

Effects / endpoints (quantitative): - CT densitometry benefit: pooled small RCTs (54 and 77 patients) showing reduction in lung density decline of 2.97 g·L−1 over 2 years (miravitlles2023ninecontroversialquestions pages 1-2). - A larger RCT (n=180) showed 0.74 g·L−1·year−1 benefit vs placebo in lung density (miravitlles2023ninecontroversialquestions pages 2-3). - Systematic review estimate: 23% slowdown in FEV1 decline (~13.4 mL/year; 95% CI 1.5–25.3 mL/year) (mazzuca2024immunologicalandhomeostatic pages 9-10).

Controversies / expert opinion: A 2023 ERS viewpoint argues that because AATD is rare and heterogeneous, trials powered for conventional COPD outcomes are difficult; CT lung densitometry is more sensitive but not widely accepted by regulators, and therefore augmentation decisions should be personalized in reference centers (miravitlles2023ninecontroversialquestions pages 1-2, miravitlles2023ninecontroversialquestions pages 2-3).

MAXO suggestions: - Intravenous infusion therapy (MAXO:0001052) - Protein replacement therapy (MAXO:0000647)

12.2 COPD/emphysema standard care

Treatment broadly follows standard COPD principles (bronchodilators, pulmonary rehab, vaccinations, smoking cessation), with augmentation as the disease-specific modifier for selected severe patients (feitosa12024recommendationsforthe pages 1-2, fouka2026alpha1antitrypsindeficiencyassociated pages 1-2).

12.3 Advanced therapeutics and emerging clinical development (selected trials)

Recombinant long-acting A1PI biologic: - INBRX-101 / SAR447537 Phase 2 active-controlled trial (ELEVAATE): compares recombinant bivalent Fc-fusion A1PI vs weekly plasma-derived augmentation, using functional AAT (anti-neutrophil elastase capacity) as primary outcome (NCT05856331; first posted 2023-05-12; completed 2025-08-06) (NCT05856331 chunk 1).

Airway gene delivery (HSV-1 vector expressing SERPINA1): - KB408 (Serpentine-1) Phase 1 inhaled HSV-1 vector delivering full-length SERPINA1 via nebulization; measures include serum AAT and neutrophil elastase in plasma and BAL (NCT06049082; first posted 2023-09-21; recruiting; start 2024-02-15) (NCT06049082 chunk 1).

RNAi gene silencing (liver-targeted; historical example): - ALN-AAT Phase 1/2 RNAi therapeutic trial in ZZ liver disease was terminated due to transient liver enzyme elevations (NCT02503683; posted 2015-07-21; terminated 2019-01) (NCT02503683 chunk 1).

In vivo gene editing (withdrawn early): - NTLA-3001 Phase 1/2 CRISPR/Cas9 AAV program for AATD-associated lung disease was withdrawn due to sponsor prioritization (NCT06622668; first posted 2024-10-02; withdrawn 2025-01-17) (NCT06622668 chunk 1).

Mechanism-based emerging strategies: Reviews describe iPSC-based and CRISPR gene editing approaches for disease modeling and potential curative strategies, including mutation correction to test causality and evaluate therapeutics (yang2025nextgenerationregenerativetherapies pages 1-2, yang2025nextgenerationregenerativetherapies pages 2-4).

13. Prevention

13.1 Primary prevention

  • Avoidance of smoking (including passive exposure) and smoking cessation are central preventative strategies; early genetic diagnosis enables preventive counseling (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2).

13.2 Secondary prevention

  • Targeted testing in COPD and other high-risk clinical settings is emphasized due to major underdiagnosis and earlier-onset disease (feitosa12024recommendationsforthe pages 1-2, turner2025advancingtheunderstanding pages 1-3).
  • Cascade/family testing is recommended as a case-finding tool and equity measure (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2, feitosa12024recommendationsforthe pages 1-2).

13.3 Tertiary prevention

  • Augmentation therapy aims to slow emphysema progression measured by CT densitometry (miravitlles2023ninecontroversialquestions pages 1-2, miravitlles2023ninecontroversialquestions pages 2-3).

14. Other species / natural disease

The current retrieved excerpts do not provide disease-specific, naturally occurring AATD analogs in non-human species with definitive genetic orthology assertions and curated identifiers (e.g., OMIA). No zoonotic transmission is applicable.

15. Model organisms / experimental models

15.1 Mouse models

Mechanistic reviews refer to PiZ mouse models as core in vivo systems for hepatic proteotoxicity and lung/liver pathobiology, including studies comparing iron-related modifiers (Hfe KO context) (yang2025nextgenerationregenerativetherapies pages 2-4).

15.2 Human iPSC / organoids and gene editing

Recent reviews describe the use of patient-derived iPSCs, iPSC-derived organoids, and CRISPR-based gene correction to model AATD and to link genotype to cellular phenotypes, supporting drug discovery and regenerative approaches (yang2025nextgenerationregenerativetherapies pages 1-2, yang2025nextgenerationregenerativetherapies pages 2-4).

15.3 Clinical “model” resources: real-world registry

The EARCO registry provides a large-scale longitudinal observational framework for genotype/phenotype and treatment-effect modeling, including augmentation therapy effects on emphysema progression, FEV1, QoL, and mortality (NCT04180319) (NCT04180319 chunk 1).

Visual evidence (guideline figures/tables retrieved)

  • SERPINA1 allele chart / clinical significance (includes Z/S/null and clinical risk associations): (feitosa12024recommendationsforthe media 68858213)
  • Diagnostic algorithm figure for AATD confirmation after screening serum AAT and/or genotyping: (feitosa12024recommendationsforthe media f6c82200)
  • Augmentation therapy criteria across international guidance (thresholds/criteria table): (feitosa12024recommendationsforthe media 1c9be2df)

Direct abstract quotes (supporting key statements)

  • Underdiagnosis and organ involvement: “Unfortunately, underdiagnosis is quite common; it is possible that only 10% of cases are diagnosed.” (Feitosa et al., 2024, Jornal Brasileiro de Pneumologia, published Nov 2024, https://doi.org/10.36416/1806-3756/e20240235) (feitosa12024recommendationsforthe pages 1-2)
  • Augmentation therapy effects (mechanistic/endpoint framing): “Augmentation therapy with AAT increases serum and pulmonary epithelial AAT levels, restores anti-elastase capacity, and decreases inflammatory mediators in the lung.” (Feitosa, 2023, Drugs in Context, published Jul 2023, https://doi.org/10.7573/dic.2023-3-1) (feitosa2023diagnosisandaugmentation pages 1-2)
  • Augmentation therapy trial limitations: “Because AATD is a rare disease, it has not been possible to conduct randomised, placebo-controlled trials that are adequately powered for … outcomes … such as lung function decline, exacerbations, symptoms or quality of life.” (Miravitlles et al., 2023, European Respiratory Review, published Dec 2023, https://doi.org/10.1183/16000617.0170-2023) (miravitlles2023ninecontroversialquestions pages 1-2)

Key real-world implementation points (2023–2024 emphasis)

  • Guideline-based case finding and treatment thresholds (2024): severe deficiency defined by AAT <57 mg/dL or <11 µM, with phenotyping/genotyping confirmation and COPD-like management plus augmentation in selected severe cases (feitosa12024recommendationsforthe pages 1-2, feitosa12024recommendationsforthe media 1c9be2df).
  • Equity and screening discussion (2024 ATS editorial): AATD remains underdiagnosed; early genetic diagnosis enables preventive smoking cessation and family testing; U.S. lacks newborn screening and broad screening programs (mcelvaney2024undiagnosedalpha1antitrypsin pages 1-2).

Requested items not fully satisfied from retrieved evidence

  • OMIM / Orphanet / ICD-10/ICD-11 / MeSH IDs: not extractable from currently retrieved texts.
  • Population incidence: not found in retrieved excerpts.
  • Comprehensive protective-factor catalog (beyond smoking avoidance): insufficient evidence in retrieved excerpts.
  • Validated epigenetic biomarkers: not extractable from retrieved excerpts.

References

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  2. (feitosa12024recommendationsforthe pages 2-3): Paulo Henrique Ramos Feitosa1, Maria Vera Cruz de Oliveira Castellano2, Claudia Henrique da Costa, Amanda da Rocha Oliveira Cardoso4, Luiz Fernando Ferreira Pereira5, Frederico Leon Arrabal Fernandes6, Fábio Marcelo Costa7, Manuela Brisot Felisbino8, Alina Faria França de Oliveira9, Jose R Jardim10, and Marc Miravitlles11. Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency. Jornal Brasileiro de Pneumologia, 50:e20240235, Nov 2024. URL: https://doi.org/10.36416/1806-3756/e20240235, doi:10.36416/1806-3756/e20240235. This article has 9 citations and is from a peer-reviewed journal.

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  13. (mazzuca2024immunologicalandhomeostatic pages 1-2): Carmen Mazzuca, Laura Vitiello, Silvia Travaglini, Fatima Maurizi, Panaiotis Finamore, Simona Santangelo, Amelia Rigon, Marta Vadacca, Silvia Angeletti, and Simone Scarlata. Immunological and homeostatic pathways of alpha -1 antitrypsin: a new therapeutic potential. Frontiers in Immunology, Aug 2024. URL: https://doi.org/10.3389/fimmu.2024.1443297, doi:10.3389/fimmu.2024.1443297. This article has 29 citations and is from a peer-reviewed journal.

  14. (ferrarotti2024rarevariantsin pages 1-2): Ilaria Ferrarotti, Marion Wencker, and Joanna Chorostowska-Wynimko. Rare variants in alpha 1 antitrypsin deficiency: a systematic literature review. Orphanet Journal of Rare Diseases, Feb 2024. URL: https://doi.org/10.1186/s13023-024-03069-1, doi:10.1186/s13023-024-03069-1. This article has 33 citations and is from a peer-reviewed journal.

  15. (yang2025nextgenerationregenerativetherapies pages 2-4): Se-Ran Yang and Hyung-Ryong Kim. Next-generation regenerative therapies for alpha-1 antitrypsin deficiency: molecular pathogenesis to clinical translation. International Journal of Molecular Sciences, 26:8504, Sep 2025. URL: https://doi.org/10.3390/ijms26178504, doi:10.3390/ijms26178504. This article has 1 citations.

  16. (yang2025nextgenerationregenerativetherapies pages 5-7): Se-Ran Yang and Hyung-Ryong Kim. Next-generation regenerative therapies for alpha-1 antitrypsin deficiency: molecular pathogenesis to clinical translation. International Journal of Molecular Sciences, 26:8504, Sep 2025. URL: https://doi.org/10.3390/ijms26178504, doi:10.3390/ijms26178504. This article has 1 citations.

  17. (yang2025nextgenerationregenerativetherapies pages 9-10): Se-Ran Yang and Hyung-Ryong Kim. Next-generation regenerative therapies for alpha-1 antitrypsin deficiency: molecular pathogenesis to clinical translation. International Journal of Molecular Sciences, 26:8504, Sep 2025. URL: https://doi.org/10.3390/ijms26178504, doi:10.3390/ijms26178504. This article has 1 citations.

  18. (yang2025nextgenerationregenerativetherapies pages 4-5): Se-Ran Yang and Hyung-Ryong Kim. Next-generation regenerative therapies for alpha-1 antitrypsin deficiency: molecular pathogenesis to clinical translation. International Journal of Molecular Sciences, 26:8504, Sep 2025. URL: https://doi.org/10.3390/ijms26178504, doi:10.3390/ijms26178504. This article has 1 citations.

  19. (mazzuca2024immunologicalandhomeostatic pages 9-10): Carmen Mazzuca, Laura Vitiello, Silvia Travaglini, Fatima Maurizi, Panaiotis Finamore, Simona Santangelo, Amelia Rigon, Marta Vadacca, Silvia Angeletti, and Simone Scarlata. Immunological and homeostatic pathways of alpha -1 antitrypsin: a new therapeutic potential. Frontiers in Immunology, Aug 2024. URL: https://doi.org/10.3389/fimmu.2024.1443297, doi:10.3389/fimmu.2024.1443297. This article has 29 citations and is from a peer-reviewed journal.

  20. (miravitlles2023ninecontroversialquestions pages 1-2): Marc Miravitlles, Antonio Anzueto, and Miriam Barrecheguren. Nine controversial questions about augmentation therapy for alpha-1 antitrypsin deficiency: a viewpoint. European Respiratory Review, 32:230170, Dec 2023. URL: https://doi.org/10.1183/16000617.0170-2023, doi:10.1183/16000617.0170-2023. This article has 24 citations and is from a peer-reviewed journal.

  21. (feitosa12024recommendationsforthe media f6c82200): Paulo Henrique Ramos Feitosa1, Maria Vera Cruz de Oliveira Castellano2, Claudia Henrique da Costa, Amanda da Rocha Oliveira Cardoso4, Luiz Fernando Ferreira Pereira5, Frederico Leon Arrabal Fernandes6, Fábio Marcelo Costa7, Manuela Brisot Felisbino8, Alina Faria França de Oliveira9, Jose R Jardim10, and Marc Miravitlles11. Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency. Jornal Brasileiro de Pneumologia, 50:e20240235, Nov 2024. URL: https://doi.org/10.36416/1806-3756/e20240235, doi:10.36416/1806-3756/e20240235. This article has 9 citations and is from a peer-reviewed journal.

  22. (ellis2023qualityoflife pages 3-4): Paul R. Ellis, Kristen E. Holm, Radmila Choate, David M. Mannino, Robert A. Stockley, Robert A. Sandhaus, and Alice M. Turner. Quality of life and mortality outcomes for augmentation naïve and augmented patients with severe alpha-1 antitrypsin deficiency. Chronic obstructive pulmonary diseases, 10:139-147, Feb 2023. URL: https://doi.org/10.15326/jcopdf.2022.0339, doi:10.15326/jcopdf.2022.0339. This article has 17 citations.

  23. (feitosa2023diagnosisandaugmentation pages 2-4): Paulo Henrique Ramos Feitosa. Diagnosis and augmentation therapy for alpha-1 antitrypsin deficiency: current knowledge and future potential. Drugs in Context, 12:1-9, Jul 2023. URL: https://doi.org/10.7573/dic.2023-3-1, doi:10.7573/dic.2023-3-1. This article has 17 citations.

  24. (NCT05856331 chunk 1): Study of SAR447537 (INBRX-101) Compared to Plasma-derived A1PI Therapy in Adults With AATD Emphysema. Sanofi. 2023. ClinicalTrials.gov Identifier: NCT05856331

  25. (NCT06049082 chunk 1): A Study of KB408 for the Treatment of Alpha-1 Antitrypsin Deficiency. Krystal Biotech, Inc.. 2024. ClinicalTrials.gov Identifier: NCT06049082

  26. (NCT02503683 chunk 1): A Study of an Investigational Drug, ALN-AAT, in Healthy Adult Subjects and Patients With ZZ Type Alpha-1 Antitrypsin Deficiency Liver Disease. Alnylam Pharmaceuticals. 2015. ClinicalTrials.gov Identifier: NCT02503683

  27. (NCT06622668 chunk 1): NTLA-3001 in Adults with Alpha-1 Antitrypsin Deficiency-Associated Lung Disease. Intellia Therapeutics. 2024. ClinicalTrials.gov Identifier: NCT06622668

  28. (yang2025nextgenerationregenerativetherapies pages 1-2): Se-Ran Yang and Hyung-Ryong Kim. Next-generation regenerative therapies for alpha-1 antitrypsin deficiency: molecular pathogenesis to clinical translation. International Journal of Molecular Sciences, 26:8504, Sep 2025. URL: https://doi.org/10.3390/ijms26178504, doi:10.3390/ijms26178504. This article has 1 citations.

  29. (feitosa12024recommendationsforthe media 68858213): Paulo Henrique Ramos Feitosa1, Maria Vera Cruz de Oliveira Castellano2, Claudia Henrique da Costa, Amanda da Rocha Oliveira Cardoso4, Luiz Fernando Ferreira Pereira5, Frederico Leon Arrabal Fernandes6, Fábio Marcelo Costa7, Manuela Brisot Felisbino8, Alina Faria França de Oliveira9, Jose R Jardim10, and Marc Miravitlles11. Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency. Jornal Brasileiro de Pneumologia, 50:e20240235, Nov 2024. URL: https://doi.org/10.36416/1806-3756/e20240235, doi:10.36416/1806-3756/e20240235. This article has 9 citations and is from a peer-reviewed journal.

  30. (feitosa12024recommendationsforthe media 1c9be2df): Paulo Henrique Ramos Feitosa1, Maria Vera Cruz de Oliveira Castellano2, Claudia Henrique da Costa, Amanda da Rocha Oliveira Cardoso4, Luiz Fernando Ferreira Pereira5, Frederico Leon Arrabal Fernandes6, Fábio Marcelo Costa7, Manuela Brisot Felisbino8, Alina Faria França de Oliveira9, Jose R Jardim10, and Marc Miravitlles11. Recommendations for the diagnosis and treatment of alpha-1 antitrypsin deficiency. Jornal Brasileiro de Pneumologia, 50:e20240235, Nov 2024. URL: https://doi.org/10.36416/1806-3756/e20240235, doi:10.36416/1806-3756/e20240235. This article has 9 citations and is from a peer-reviewed journal.

OpenScientist ▸
1. Disease Information
openscientist-autonomous 48 citations 2026-05-05T03:26:59.930512

1. Disease Information

Overview

Alpha-1 Antitrypsin Deficiency (AATD) is a hereditary disorder characterized by reduced circulating levels and/or impaired function of alpha-1 antitrypsin (AAT), a 52-kDa acute-phase glycoprotein and the most abundant circulating serine protease inhibitor (serpin). AAT's primary physiological role is to neutralize neutrophil elastase (NE) in the lungs, thereby protecting the delicate alveolar architecture from proteolytic damage during inflammatory responses. When AAT is deficient or dysfunctional, the resulting protease-antiprotease imbalance leads to progressive destruction of lung tissue and development of early-onset panacinar emphysema. Concurrently, the most common pathogenic variants cause the AAT protein to misfold and accumulate as ordered polymers within the ER of hepatocytes, leading to a spectrum of liver diseases ranging from neonatal cholestasis to adult-onset cirrhosis and hepatocellular carcinoma.

As stated by Strnad et al.: "alpha1-Antitrypsin deficiency (A1ATD) is an inherited disorder caused by mutations in SERPINA1, leading to liver and lung disease" (PMID: 27465791).

Key Identifiers

Database Identifier
OMIM #613490 (AATD); *107400 (SERPINA1 gene)
Orphanet ORPHA:60
ICD-10 E88.01 (Alpha-1 antitrypsin deficiency)
ICD-11 5C50.0
MeSH D019896 (Alpha 1-Antitrypsin Deficiency)
MONDO MONDO:0011073
GARD 5784
UMLS C0221757

Synonyms and Alternative Names

  • Alpha-1 proteinase inhibitor deficiency
  • AAT deficiency / AATD
  • A1ATD / A1AD
  • Alpha-1 antiprotease deficiency
  • Pi deficiency (Protease Inhibitor deficiency)
  • Hereditary pulmonary emphysema
  • SERPINA1-related disorder

Information Sources

The information in this report is derived from aggregated disease-level resources including OMIM, Orphanet, GeneReviews, and primary peer-reviewed literature, supplemented by data from population-based registries (Swedish neonatal screening cohort, Danish national registries, Alpha-1 Foundation Research Registry), clinical trial databases, and large cohort studies (COPDGene, UK Biobank).

2. Etiology

Disease Causal Factors

AATD is a genetic disorder with a strictly Mendelian basis. The primary cause is biallelic pathogenic mutations in the SERPINA1 gene. The disorder follows an autosomal codominant inheritance pattern, meaning that each allele contributes independently to the circulating AAT level.

The two most common pathogenic alleles are: - Pi*Z (Glu342Lys): The most clinically significant deficiency allele, present in ~95% of clinically recognized AATD. The Z mutation causes the AAT protein to misfold, forming ordered polymers within the hepatocyte ER. Homozygotes (PiZZ) have serum AAT levels of only 10–15% of normal (~3–7 micromol/L vs. normal 20–53 micromol/L). - PiS (Glu264Val): A milder deficiency allele producing ~60% of normal AAT levels. PiSS homozygotes rarely develop clinical disease, but PiSZ compound heterozygotes may develop emphysema, particularly with smoking.

As described by Seixas et al.: the SERPINA1 gene "has 132 low-frequency variants (<1%), where AATD mutations are not evenly distributed across the three-dimensional structure and tend to cluster in functional domains like the gate or the shutter" (PMID: 27296815).

Genetic Risk Factors

Risk Factor Detail
Pi*ZZ genotype ~85% AAT retention in hepatocyte ER; serum levels 10–15% of normal
Pi*SZ genotype Intermediate risk, particularly with smoking
Pi*MZ genotype Heterozygous carrier; 2–5% of general population; increased emphysema risk in smokers (PMID: 29070580)
Rare/null alleles >130 rare SERPINA1 variants including null alleles producing no AAT protein
Modifier genes GWAS and candidate gene studies suggest modifier loci influence lung function decline variability (PMID: 32621460)

Environmental Risk Factors

  • Cigarette smoking: The single most important environmental risk factor. Smoking accelerates FEV1 decline by 2–3x in PiZZ individuals and can reduce life expectancy by ~20 years. Even PiMZ heterozygous smokers have increased emphysema risk (PMID: 29070580).
  • Occupational dust/fume exposure: Agricultural dust, mineral dust, and industrial fumes accelerate lung function decline.
  • Air pollution: Particulate matter and ozone exposure worsen pulmonary outcomes.
  • Recurrent respiratory infections: Exacerbations accelerate lung tissue destruction.
  • Alcohol consumption: May accelerate liver disease progression in AATD.

Protective Factors

  • Pi*M allele: The normal wild-type allele producing full-function AAT.
  • Never-smoking status: The most critical protective behavior.
  • Early diagnosis and smoking avoidance: Identified through newborn screening or family cascade testing.
  • Augmentation therapy: Slows lung density decline in emphysema.

Gene-Environment Interactions

The interaction between SERPINA1 genotype and environmental exposures is the central determinant of disease expression. PiZZ individuals who never smoke may maintain relatively preserved lung function into their 50s–60s, while PiZZ smokers typically develop symptomatic emphysema in their 30s–40s. PiMZ heterozygotes — comprising 2–5% of the general population — have increased risk of emphysema only in the context of smoking or massive environmental exposures, with "carefully designed family studies show[ing] an increased risk of emphysema in MZ smokers"* (PMID: 29070580).

3. Phenotypes

Pulmonary Manifestations

Panacinar Emphysema (most common pulmonary phenotype) - HPO: HP:0002097 (Emphysema) - Onset: Typically 30–50 years in smokers; 50–60+ years in never-smokers - Severity: Variable; progressive - Frequency: ~60–70% of PiZZ adults develop clinically significant emphysema - Characteristics: Basal/lower-lobe predominance (distinguishing from smoking-related centrilobular emphysema); panacinar distribution - QoL impact:* Progressive dyspnea, exercise limitation, disability

"The most common genotype associated with pulmonary disease is the ZZ genotype, and the most frequent pulmonary manifestation is emphysema" (PMID: 38599244).

Chronic Obstructive Pulmonary Disease (COPD) - HPO: HP:0006510 (Chronic obstructive pulmonary disease) - Onset: Adult - Frequency: AATD accounts for ~1–2% of all COPD cases - Progression: Progressive airflow limitation; FEV1 decline accelerated by smoking

Bronchiectasis - HPO: HP:0002110 (Bronchiectasis) - Onset: Adult - Frequency: Present in significant minority; 100% of AATD patients showed CT features of bronchiectasis in one study (PMID: 41364209)

Bronchial Asthma (debated association) - HPO: HP:0002099 (Asthma) - Frequency: Variable (1.4–44.6% in AATD registries) - Evidence: Association remains controversial; "current evidence is insufficient to support a direct causal role for AATD mutations in asthma development" (PMID: 40563447)

Hepatic Manifestations

Neonatal Cholestasis - HPO: HP:0006260 (Neonatal cholestasis) - Onset: Neonatal (first weeks of life) - Frequency: ~10–15% of PiZZ neonates; cholestasis was the presenting manifestation in 6/8 children in one series (PMID: 25518532) - Progression:* Most cases resolve spontaneously; ~2–3% progress to severe liver disease requiring transplant in childhood

Hepatic Fibrosis and Cirrhosis - HPO: HP:0001394 (Cirrhosis), HP:0001395 (Hepatic fibrosis) - Onset: Childhood through late adulthood - Frequency: Pooled pediatric prevalence: 41.3% fibrosis, 17.3% cirrhosis (PMID: 41791905). In adults, up to 25% of PiZZ individuals may develop cirrhosis by late adulthood. - Progression:* Progressive; correlates with intrahepatic AAT polymer load

Hepatocellular Carcinoma - HPO: HP:0001402 (Hepatocellular carcinoma) - Onset: Late adulthood - Frequency: Increased risk in cirrhotic AATD patients

Dermatologic Manifestations

Necrotizing Panniculitis - HPO: HP:0012490 (Panniculitis) - Onset: Any age; typically adulthood - Frequency: ~0.1% of PiZZ individuals (rarest clinical manifestation) - Characteristics:* Painful subcutaneous nodules with neutrophilic infiltrates and fat necrosis; can cause severe morbidity including limb amputation (PMID: 28058497)

Other Manifestations

Phenotype HPO Term Frequency
Granulomatosis with polyangiitis (vasculitis) HP:0100820 Rare
Cholesteatoma (increased risk, HR 3.62) — Rare (PMID: 40888606)
Obstructive sleep apnea HP:0002870 31.6% of AATD patients (PMID: 40550287)

Laboratory Abnormalities

  • Reduced serum AAT levels (Pi*ZZ: <57 mg/dL or <11 micromol/L; normal: 100–220 mg/dL)
  • Elevated liver transaminases (ALT, AST) in hepatic involvement
  • Elevated GGT in cholestasis
  • Obstructive pattern on pulmonary function testing (reduced FEV1, reduced FEV1/FVC ratio)
  • Reduced DLCO (diffusing capacity)

4. Genetic/Molecular Information

Causal Gene

  • Gene: SERPINA1 (Serpin Family A Member 1)
  • HGNC: HGNC:8941
  • NCBI Gene ID: 5265
  • OMIM: *107400
  • Chromosomal location: 14q32.13
  • Protein: Alpha-1 antitrypsin (AAT) / Alpha-1 proteinase inhibitor (A1PI)
  • UniProt: P01009
  • Structure: 394 amino acids, 52 kDa glycoprotein; member of serpin superfamily

Pathogenic Variants

Variant Protein Change dbSNP Type gnomAD Frequency Clinical Significance
Pi*Z Glu342Lys rs28929474 Missense ~1–2% in Northern Europeans Pathogenic; causes polymerization and severe deficiency
Pi*S Glu264Val rs17580 Missense ~2–4% in Southern Europeans Pathogenic; mild deficiency (60% of normal)
Pi*Null Various Various Nonsense/frameshift Very rare Pathogenic; no AAT production
Pi*Mmalton Phe52del — In-frame deletion Rare Pathogenic; ER retention and polymerization
Pi*Siiyama Ser53Phe — Missense Rare (Japanese) Pathogenic; polymerization
Pi*I Arg39Cys — Missense Rare Likely pathogenic
Pi*F — — Missense Rare VUS to likely pathogenic

All pathogenic variants are germline in origin. The SERPINA1 gene contains approximately 120 known variants, of which 132 are low-frequency (<1%). The disease follows codominant inheritance: each allele independently contributes to serum AAT levels.

Functional consequences: - Z allele: Causes a conformational change in the AAT protein that promotes loop-sheet polymerization. The Glu342Lys substitution destabilizes the relationship between the reactive center loop (RCL) and beta-sheet A, creating a kinetically trapped intermediate prone to intermolecular domain swapping. This results in both loss of function (reduced secretion and antiprotease activity) and gain of toxic function (intracellular polymer accumulation). - S allele: Causes milder misfolding with less polymer formation; primarily loss-of-function. - Null alleles: Complete loss of function with no protein production; no liver disease risk (no polymer formation) but severe lung disease risk.

Modifier Genes

Genetic modifiers contribute to the marked phenotypic heterogeneity in AATD. Candidate modifiers include: - Genes in ERAD and autophagy pathways (determining efficiency of misfolded Z-AAT clearance) (PMID: 38336172) - Inflammatory response genes (IL4R, AGER identified as COPD-associated proteins in AATD) (PMID: 40665347) - Matrix metalloproteinase genes - A genome-wide association study (GWAS) specific to AATD lung function has been proposed but not yet completed (PMID: 32621460)

Epigenetic Information

  • JNK pathway activation upregulates SERPINA1 gene expression via c-Jun, creating a vicious cycle of increased Z-AAT production and accumulation (PMID: 28073160)
  • miR-34b/c is upregulated by JNK and FOXO3 and protects against liver fibrosis in AATD (PMID: 33649241)
  • CHOP and c-JUN transcription factors upregulate mutant Z alpha1-antitrypsin expression (PMID: 32723872)

Chromosomal Abnormalities

Not applicable — AATD is caused by point mutations and small insertions/deletions, not chromosomal structural abnormalities.

5. Environmental Information

Environmental Factors

  • Cigarette smoke: Directly oxidizes Met358 in the reactive center loop of AAT, inactivating its antiprotease function. Also increases neutrophil recruitment and NE release in the lung.
  • Air pollution: Particulate matter (PM2.5, PM10) and ozone promote pulmonary inflammation.
  • Occupational exposures: Mineral dust, agricultural dust, and chemical fumes.
  • Secondhand smoke: Also accelerates lung disease.

Lifestyle Factors

Factor Impact
Smoking Most critical modifiable risk; accelerates FEV1 decline 2–3x
Alcohol May accelerate hepatic disease progression
Exercise Pulmonary rehabilitation improves functional capacity
Diet/nutrition Maintaining healthy BMI important; obesity associated with increased OSA risk in AATD (PMID: 40550287)

Infectious Agents

  • Respiratory infections (bacterial and viral) trigger exacerbations that accelerate emphysema progression.
  • Viral hepatitis co-infection significantly worsens prognosis of AATD-associated liver disease — in one study, 78% of AATD patients with chronic liver disease had positive viral markers, and life expectancy was markedly reduced with co-infection (PMID: 8578172).
  • COVID-19: AAT levels and function may influence COVID-19 severity; AAT has been proposed as a potential therapeutic agent for COVID-19 due to its ability to inhibit TMPRSS-2 and reduce inflammation (PMID: 33239231).

6. Mechanism / Pathophysiology

Key Finding: Dual Pathogenic Mechanism

AATD is unique among protein-misfolding diseases in operating through two simultaneous pathogenic mechanisms, as established by Kalsheker et al.: "The AAT deficiency is unique among the protein-misfolding diseases in that it causes target organ injury by both loss-of-function and gain-of-toxic function mechanisms" (PMID: 28927525).

Mechanism 1: Loss-of-Function (Lung Disease)

Causal chain:

SERPINA1 Z mutation -> AAT misfolding -> ER retention (~85% retained)
-> Reduced circulating AAT (10-15% of normal)
-> Inadequate neutrophil elastase inhibition in lungs
-> Protease-antiprotease imbalance
-> Unopposed NE activity -> Elastin degradation
-> Alveolar wall destruction -> Panacinar emphysema

As described: "Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterized by reduced circulating levels and/or impaired function of alpha-1 antitrypsin (AAT), a key serine protease inhibitor, in which loss of effective antiprotease protection results in unchecked neutrophil elastase activity and progressive lung tissue destruction" (PMID: 42075511).

Key molecular pathways: - Protease-antiprotease balance (GO:0010951 - negative regulation of endopeptidase activity) - NF-kB inflammatory signaling - Neutrophil chemotaxis and NET formation - Elastin degradation and extracellular matrix remodeling (GO:0030574 - collagen catabolic process)

Cell types involved: - Neutrophils (CL:0000775) — source of NE and other proteases - Alveolar macrophages (CL:0000583) — inflammatory mediators; Z-AAT polymer accumulation impairs phagocytic function - Type I and Type II alveolar epithelial cells (CL:0002062, CL:0002063) — target of proteolytic damage - Monocytes (CL:0000576) — reduced HLA-DR+ protective subsets in PiZZ patients (PMID: 40943425)

Mechanism 2: Gain-of-Toxic-Function (Liver Disease)

Causal chain:

SERPINA1 Z mutation -> AAT misfolding in hepatocyte ER
-> Ordered polymer formation (loop-sheet or domain-swap mechanism)
-> ER stress and Unfolded Protein Response (UPR) activation
-> JNK/c-Jun pathway activation -> Increased SERPINA1 transcription (vicious cycle)
-> ERAD and autophagy activation (compensatory but insufficient)
-> Hepatocyte senescence (nuclear p21 expression, shortened telomeres)
-> Chronic hepatic inflammation -> Fibrosis -> Cirrhosis -> HCC

Key Finding: Polymer Load-Outcome Correlation. In a landmark study of 92 patients: "The AAT polymer load correlated closely with hepatic fibrosis stage and long-term clinical outcome, independent of homozygous or heterozygous status" (PMID: 32726073). Polymers correlated with failure of cell cycle progression, accelerated aging (shortened telomeres), and hepatocyte senescence marked by nuclear p21 expression and enlarged nuclei.

Key molecular pathways: - Unfolded Protein Response (UPR): Selective attenuation — PERK and IRE1-alpha branches suppressed while ATF6-alpha remains active (PMID: 35621045) - JNK/c-Jun signaling: Activated by Z-AAT; drives increased SERPINA1 transcription (PMID: 28073160) - mTOR/AMPK pathway: mTORC1 activity attenuated; AMPK activated; pharmacological mTOR inhibition reduces Z-AAT accumulation (PMID: 42072628) - ERAD pathway (GO:0036503): Initial clearance mechanism for misfolded Z-AAT - Macroautophagy (GO:0016236): Becomes increasingly important over time as Z-AAT accumulation persists (PMID: 38336172) - ERLAD pathway: SEC24C and p24-family proteins facilitate ER-to-lysosome clearance (PMID: 38294851) - Apoptosis (GO:0006915): Activated caspase cascades detected in Z hepatocytes - NF-kB pathway activation - TLR7 signaling: Alu RNA activates TLR7 in Z-AAT macrophages, inducing NLRP3 inflammasome expression (PMID: 35730566)

Protein dysfunction: The Z mutation (Glu342Lys) disrupts the critical interaction between the reactive center loop and beta-sheet A of the AAT molecule, creating a conformational intermediate prone to polymerization. The polymer structure involves extensive domain swapping between serpin monomers, as supported by crystallographic and biophysical studies (PMID: 20731544, PMID: 20667823).

Biochemical Abnormalities

  • Serine protease inhibitor deficiency: AAT normally inhibits NE with a second-order rate constant of ~6.5 x 10^7 M^-1 s^-1; Z-AAT has reduced inhibitory activity
  • Neutrophil elastase excess: Unchecked NE degrades elastin, collagen, and other ECM components
  • Elevated fibrinogen degradation products: Aa-Val360 is a biomarker of disease activity reflecting elastase-mediated fibrinogenolysis (PMID: 40967767)

7. Anatomical Structures Affected

Organ Level

Level Structures UBERON Term
Primary Lung (lower lobes predominantly) UBERON:0002048
Primary Liver UBERON:0002107
Secondary Skin (panniculitis) UBERON:0002097
Secondary Kidney (vasculitis, rare) UBERON:0002113
Secondary Middle ear (cholesteatoma, increased risk) UBERON:0001756

Body systems: Respiratory system, digestive system (hepatobiliary), integumentary system, immune system.

Tissue and Cell Level

Tissue/Cell Ontology Term Involvement
Hepatocytes CL:0000182 Primary site of AAT synthesis and Z-AAT polymer accumulation
Alveolar epithelium CL:0002062/CL:0002063 Target of proteolytic destruction
Neutrophils CL:0000775 Source of NE; dysregulated in AATD
Alveolar macrophages CL:0000583 Impaired phagocytosis; polymer accumulation
Monocytes CL:0000576 Reduced protective HLA-DR+ subsets
Hepatic stellate cells CL:0000632 Activated in fibrosis
Kupffer cells CL:0000091 Inflammatory response in liver
Subcutaneous adipocytes CL:0000136 Target in panniculitis

Subcellular Level

Compartment GO Term Relevance
Endoplasmic reticulum GO:0005783 Site of Z-AAT polymerization and retention
ER lumen GO:0005788 Z-AAT polymer accumulation
Lysosome GO:0005764 Autophagy/ERLAD-mediated clearance
Autophagosome GO:0005776 Compensatory clearance pathway
Extracellular space GO:0005615 Normal AAT secretion site; deficient in AATD

8. Temporal Development

Onset

  • Neonatal: Cholestatic jaundice in ~10–15% of Pi*ZZ neonates (presents in first weeks of life)
  • Childhood: Hepatic fibrosis/cirrhosis in a subset; liver transplantation may be needed
  • Adult (30–50 years): Emphysema onset, especially in smokers
  • Late adult (50–70 years): Emphysema in never-smokers; adult-onset liver disease including cirrhosis and HCC
  • Onset pattern: Insidious (both lung and liver disease develop gradually)

Progression

  • Lung disease: Progressive, with annual FEV1 decline of ~50–80 mL/year in symptomatic patients (vs. ~30 mL/year in healthy individuals). Rate accelerated by smoking and exacerbations.
  • Liver disease: Progressive fibrosis correlating with intrahepatic polymer load. In children, "declining rates of elevated liver enzymes with age should not be interpreted as disease resolution" (PMID: 41791905).
  • Disease course: Chronic, lifelong, progressive.
  • Duration: Lifelong (no cure except liver transplantation for hepatic component).

Critical Periods

  • Neonatal period: Window for identification via newborn screening; cholestatic presentation
  • Adolescence/young adulthood: Critical window for smoking prevention
  • Early adulthood (20s–30s): ELF markers already elevated in asymptomatic ZZ individuals by age 34, indicating subclinical hepatic injury (PMID: 21617532)
  • Pre-emphysema phase: Window for augmentation therapy initiation

9. Inheritance and Population

Inheritance Pattern

  • Mode: Autosomal codominant
  • Penetrance: Incomplete and highly variable. Not all Pi*ZZ individuals develop clinical disease. Approximately 60–70% develop emphysema; ~10–15% of neonates develop cholestasis; ~25% develop cirrhosis by late adulthood.
  • Expressivity: Highly variable — ranging from asymptomatic carriers to severe neonatal liver failure or early-onset emphysema.
  • Genetic anticipation: Not applicable (not a repeat expansion disorder).
  • Carrier frequency: Pi*MZ heterozygotes comprise 2–5% of European populations.

Epidemiology

Metric Value Source
Prevalence (Pi*ZZ) 1 in 2,000–3,500 in Northern Europeans OMIM, Orphanet
Prevalence (diagnosed AATD, Norway) 10.7 per 100,000 PMID: 41216004
Incidence (Norway) 1.4 per 100,000 person-years PMID: 41216004
Estimated worldwide affected ~3.4 million (two deficiency alleles) WHO/Alpha-1 Foundation
Underdiagnosis rate ~90% undiagnosed Multiple sources
Mortality rate ratio vs. general population 6.2 (95% CI: 5.3–7.2) PMID: 41216004

Population Demographics

  • Highest prevalence: Northern European/Scandinavian populations (particularly Scandinavian, British, and Iberian)
  • Z allele distribution: Highest frequency in Northern/Western Europe; follows a gradient decreasing from north to south and west to east
  • S allele distribution: Highest in Iberian Peninsula; more evenly distributed across Southern Europe
  • Founder effects: The Z allele is believed to have originated from a single founder in Scandinavia ~2,000 years ago
  • Sex ratio: Approximately 1:1 (equal prevalence in males and females)
  • Geographic distribution of specific variants: PiMmalton prominent in Sardinia and Italy; PiSiiyama in Japan

10. Diagnostics

Diagnostic Algorithm

The recommended stepwise diagnostic approach, as endorsed by ATS/ERS guidelines:

  1. Serum AAT level measurement (nephelometry or immunoturbidimetry)
  2. Normal: 100–220 mg/dL (20–53 micromol/L)
  3. Threshold for further testing: <110 mg/dL (<20 micromol/L)

  4. Severe deficiency: <=57 mg/dL

  5. AAT phenotyping by isoelectric focusing (IEF)

  6. Identifies protein variants based on migration pattern (PiMM, PiMZ, PiZZ, PiSZ, etc.)

  7. SERPINA1 genotyping (PCR-based or sequencing)

  8. Targeted genotyping for common alleles (Z, S)

  9. Full gene sequencing for rare/novel variants

  10. Confirmatory testing: Serum AAT level + genotype/phenotype concordance

Clinical Tests

Test Purpose Key Findings
Serum AAT level Initial screen <57 mg/dL in Pi*ZZ
Pulmonary function tests Assess lung involvement Obstructive pattern; reduced FEV1, DLCO
HRCT chest Characterize emphysema Basal panacinar emphysema, bronchiectasis
Liver function tests Assess hepatic involvement Elevated ALT, AST, GGT
Liver elastography/biopsy Stage liver fibrosis PAS-D positive globules in hepatocytes
ELF panel Non-invasive fibrosis assessment Elevated TIMP-1, PIIINP, HA in ZZ vs. MM (PMID: 21617532)
IGF-1 Liver disease severity predictor Reduced in higher fibrosis stages (PMID: 40378984)

Genetic Testing

  • Single gene testing of SERPINA1 is the primary recommended approach (MAXO:0000079)
  • Dried blood spot testing enables population screening and remote sampling
  • Full sequencing identifies rare/novel variants missed by targeted genotyping (PMID: 41789803)
  • WES/WGS: Not routinely needed but useful for atypical cases or research

Liver Biopsy Findings

  • PAS-diastase (PAS-D) positive globules in hepatocyte cytoplasm — pathognomonic
  • Immunohistochemistry: Positive for Z-AAT polymers
  • Portal inflammation, hepatic fibrosis, cirrhosis in advanced cases
  • Characteristic ER inclusions on electron microscopy

Screening

  • Newborn screening: Feasible and implemented in some countries (Sweden performed the landmark 1972–1974 neonatal screening of 200,000 newborns). The Alpha-1 Foundation has recommended pilot studies (PMID: 24121147).
  • Targeted testing: Recommended for all patients with COPD, unexplained liver disease, panniculitis, and C-ANCA-positive vasculitis.
  • Cascade screening: Testing of first-degree relatives of identified cases.
  • Bile acid profiling in DBS: Emerging screening tool for cholestatic AATD in children (PMID: 38992821).

Differential Diagnosis

  • Smoking-related COPD (centrilobular vs. panacinar distribution)
  • Non-AATD bronchiectasis
  • Asthma
  • Non-alcoholic/alcoholic liver disease
  • Other causes of neonatal cholestasis (biliary atresia, Alagille syndrome)
  • Other causes of panniculitis

11. Outcome / Prognosis

Survival and Mortality

  • Mortality rate ratio: 6.2-fold increased vs. general population (95% CI: 5.3–7.2) (PMID: 41216004)
  • Life expectancy (without liver disease): Comparable to general population (PMID: 8578172)
  • Life expectancy (with liver disease): Significantly reduced, particularly with viral co-infection
  • Liver transplant survival: Outstanding — "The overall cumulative patient survival rates post-transplant were 97.8% at 1 year, and 95.5%, 95.5%, 92.0%, 89.1% at 5, 10, 15, 20 years respectively" (PMID: 33139195)
  • Lung transplant survival: Median 6.4 years post-transplant; 82% at 1 year, 56% at 5 years, 34% at 10 years. Double lung transplant significantly better than single (7.7 vs. 4.4 years, p < 0.001) (PMID: 32911139)

Prognostic Factors

Factor Impact
Smoking status Most critical determinant of lung disease onset and severity
Genotype (PiZZ vs. PiSZ) Determines AAT level and polymer load
Intrahepatic polymer load Correlates with fibrosis stage and liver-related mortality (PMID: 32726073)
Baseline FEV1 Predicts rate of lung function decline
Exacerbation frequency Accelerates emphysema progression
Viral co-infection (liver) Dramatically worsens hepatic prognosis
IGF-1 levels Lower levels predict higher liver-related mortality (PMID: 40378984)
ELF panel markers Elevated in asymptomatic ZZ individuals; predict future liver disease (PMID: 21617532)

Complications

  • End-stage emphysema requiring transplantation
  • Cirrhosis, liver failure, hepatocellular carcinoma
  • Portopulmonary hypertension
  • Hepatopulmonary syndrome (PMID: 30066494)
  • Recurrent respiratory infections and exacerbations
  • Pneumothorax
  • Respiratory failure

12. Treatment

Augmentation Therapy (Disease-Specific, MAXO:0001298)

Intravenous AAT augmentation therapy is the only disease-specific approved treatment for AATD-associated lung disease:

  • Mechanism: Weekly IV infusion of plasma-derived, purified human AAT to raise serum levels above the protective threshold (11 micromol/L / 57 mg/dL)
  • Approved products: Prolastin-C, Aralast NP, Zemaira, Glassia (liquid)
  • Dose: 60 mg/kg/week IV
  • Efficacy: The RAPID trial demonstrated slowed progression of emphysema measured by CT density decline: 0.79 g/L/year treatment difference vs. placebo (PMID: 29430176)
  • Limitations: Expensive (~$100,000+/year), requires lifelong weekly infusions, variably available/reimbursed worldwide, no proven efficacy for liver disease

Standard COPD Therapies

  • Bronchodilators (LABA, LAMA, SABA)
  • Inhaled corticosteroids (ICS)
  • Pulmonary rehabilitation (MAXO:0000502)
  • Oxygen therapy for hypoxemia
  • Vaccinations (influenza, pneumococcal, COVID-19)

Note: Most COPD trials exclude AATD patients, so treatments are largely extrapolated (PMID: 28496314).

Surgical Interventions

  • Lung transplantation (MAXO:0001175): For end-stage emphysema; median survival 6.4 years; double transplant preferred (PMID: 32911139)
  • Liver transplantation (MAXO:0001175): Curative for liver disease; corrects the metabolic defect (donor liver produces normal M-AAT); excellent 20-year survival of 89% (PMID: 33139195)
  • Lung volume reduction surgery (LVRS): Limited data in AATD; generally less effective than in usual COPD
  • Domino liver transplantation: AATD livers have been used as domino donors for select metabolic conditions (PMID: 31556146)

Emerging Therapies

RNA Interference (RNAi)

RNAi therapeutics targeting hepatic SERPINA1 expression represent a transformative approach for liver disease:

  • ARC-AAT (Arrowhead): First-in-human study demonstrated "a dose response in serum AAT reduction... with a maximum reduction of 76.1% (HVs) vs. 78.8% (PiZZ) at this dose" (PMID: 29572094)
  • Fazirsiran (ARO-AAT, Takeda): GalNAc-conjugated siRNA; Phase 2/3 trials ongoing; achieves sustained Z-AAT knockdown
  • Belcesiran (Dicerna/Novo Nordisk): Alternative RNAi approach

Oral Neutrophil Elastase Inhibitors

Alvelestat (MPH966, Mereo BioPharma): - Oral small-molecule NE inhibitor - Two Phase 2 RCTs (ATALANTa and ASTRAEUS) in 161 participants showed: "Blood NE was significantly suppressed in both studies at both doses, with the greatest effect (>90% suppression) at alvelestat 240 mg twice daily" (PMID: 40967767) - 240 mg BID dose significantly reduced disease activity biomarker Aa-Val360

Gene Therapy and Gene Editing

  • CRISPR/Cas9: Used to create disease models and being explored for therapeutic correction (PMID: 35621045)
  • iPSC-derived models: Enable patient-specific disease modeling and drug screening (PMID: 40943425)
  • RNA editing platforms and AAV-based gene therapy in preclinical development

Chemical Chaperones

  • 4-Phenylbutyric acid (4-PBA): Shown to mediate increased secretion of functionally active Z-AAT in PiZ mice, "consistently mediated an increase in blood levels of human alpha1-AT reaching 20-50% of the levels present in PiM mice and normal humans" (PMID: 10677536)

Other Experimental Approaches

  • Inhaled AAT formulations for direct pulmonary delivery
  • Recombinant AAT fusion proteins
  • mTOR inhibitors for liver disease (PMID: 42072628)
  • JNK inhibitors for liver disease (PMID: 28073160)
  • Drug repurposing: Proteomics analyses identified antibiotics, thyroid medications, hormone therapies, and antihistamines as potential adjunctive treatments (PMID: 40665347)

Panniculitis Treatment

  • High-dose IV AAT augmentation (120 mg/kg single dose has achieved clinical remission) (PMID: 26527439)
  • Doxycycline (MMP inhibitor)
  • Colchicine for flare reduction (PMID: 28058497)

13. Prevention

Primary Prevention

  • Genetic counseling (MAXO:0000079) for affected individuals and carriers regarding reproductive planning
  • Smoking avoidance/cessation — the single most impactful preventive measure
  • Avoidance of occupational and environmental lung irritants
  • Vaccination against influenza, pneumococcal disease, and COVID-19

Secondary Prevention (Early Detection)

  • Newborn screening: Technically feasible; identifies ~1 in 2,000–3,500 newborns. Swedish experience (1972–1974 screening of 200,000 infants) demonstrated effectiveness but raised psychosocial concerns (PMID: 24121147)
  • Targeted testing: All COPD patients, unexplained liver disease, panniculitis, vasculitis
  • Cascade testing: First-degree relatives of identified cases
  • Automated alerts: Recommended for laboratories to trigger SERPINA1 genotyping when low AAT levels detected (PMID: 41883848)

Tertiary Prevention

  • Augmentation therapy to slow emphysema progression
  • Regular monitoring: Annual PFTs, periodic CT densitometry, liver function monitoring
  • Multidisciplinary care: Collaboration among pulmonology, hepatology, primary care, and pediatrics (PMID: 41883848)
  • Hepatitis vaccination: Prevent viral co-infection that worsens liver outcomes
  • Avoiding hepatotoxic medications and excessive alcohol

14. Other Species / Natural Disease

Comparative Biology

AAT (SERPINA1) is highly conserved across mammals. Key orthologous genes:

Species Gene Notes
Mus musculus Serpina1a-e (gene cluster) Five paralogs; functional redundancy
Rattus norvegicus Serpina1 Orthologous
Canis lupus familiaris SERPINA1 Orthologous
Sus scrofa SERPINA1 Orthologous

Natural Disease in Other Species

Naturally occurring AATD has not been well-documented in companion animals. However, the serpin superfamily is evolutionarily conserved, and serpin polymerization has been demonstrated in multiple model systems. AAT-like protease inhibitors are present throughout the mammalian lineage, and the protease-antiprotease balance concept applies broadly to lung homeostasis across species.

Zoonotic Potential

Not applicable — AATD is a purely genetic disorder with no infectious or zoonotic component.

15. Model Organisms

Mouse Models

PiZ transgenic mouse (most widely used model): - Transgenic for human SERPINA1 Z allele - Develops intrahepatic Z-AAT polymer accumulation with PAS-D positive globules - Recapitulates hepatic aspects: ER retention, autophagy activation, hepatocyte injury - Used for chemical chaperone studies (4-PBA increased blood AAT to 20–50% of normal levels) (PMID: 10677536) - Limitations: Murine Serpina1 gene family has 5 paralogs; mice may compensate partially; does not fully recapitulate emphysema

Novel full-length genomic DNA Pi*Z hAAT transgenic mouse: - Newer model with full human SERPINA1 genomic sequence - Shows selective UPR branch attenuation matching human disease (PMID: 35621045) - Demonstrates mTOR pathway attenuation via AMPK activation (PMID: 42072628)

JNK1/JNK2 knockout x PiZ mice: - Genetic ablation of JNK1 or JNK2 decreased Z-AAT levels in vivo (PMID: 28073160)

Cellular Models

Model Application Reference
Huh7.5Z cells (CRISPR-edited) UPR studies, drug screening PMID: 35621045
Patient-derived iPSC-hepatic cells JNK inhibitor testing, personalized medicine PMID: 28073160
iPSC-derived alveolar epithelial cells Lung disease modeling PMID: 40943425
iPSC-derived organoids Gene editing validation, drug development PMID: 40943425
COS-7 cells (transfection) Polymerization studies PMID: 20667823
Z-MDMs (monocyte-derived macrophages) TLR7/NLRP3 signaling PMID: 35730566
U937 monocytic cells AAT anti-inflammatory activity PMID: 32062078

Model Limitations

  • Mouse models do not spontaneously develop emphysema (require additional insults such as elastase instillation)
  • The five murine Serpina1 paralogs may compensate for Z-AAT effects, confounding liver disease studies
  • Cell line models lack the complex multicellular interactions of in vivo liver/lung microenvironments
  • iPSC-derived models are still being optimized for maturity and physiological relevance
  • No single model fully recapitulates both the hepatic and pulmonary manifestations simultaneously

Key Findings — Detailed Evidence

Finding 1: Dual Pathogenic Mechanism

AATD is caused by SERPINA1 gene mutations that produce a disease phenotype through two simultaneous mechanisms — a feature unique among protein-misfolding diseases. The loss-of-function mechanism involves inadequate circulating AAT leading to unchecked neutrophil elastase activity and progressive emphysema. The gain-of-toxic-function mechanism involves intracellular accumulation of polymerized Z-AAT in hepatocyte ER, causing chronic liver injury progressing to cirrhosis and HCC. ZZ homozygotes retain approximately 85% of synthesized AAT intracellularly, resulting in serum levels of only 10–15% of normal (3–7 micromol/L vs. normal 20–53 micromol/L). This dual mechanism means that therapeutic strategies must address both loss of lung protection and toxic hepatic accumulation — a challenge that has driven the development of complementary therapeutic approaches targeting each arm independently.

Finding 2: Polymer Load Predicts Liver Outcomes

A landmark study of 92 patients demonstrated that the hepatic AAT polymer load is the critical determinant of liver disease progression, correlating closely with fibrosis stage and long-term clinical outcomes regardless of whether patients were homozygous (PiZZ) or heterozygous (PiMZ). The polymer burden was associated with hallmarks of cellular senescence: nuclear p21 expression, enlarged nuclei, shortened telomeres, and failure of cell cycle progression. This finding establishes polymer accumulation — not simply AAT deficiency — as the upstream driver of hepatic pathology and validates therapeutic strategies aimed at reducing intrahepatic polymer load (such as RNAi-mediated SERPINA1 knockdown).

Finding 3: Liver Transplantation Achieves Excellent Long-Term Survival

In a cohort of 90 patients transplanted for AATD-related liver disease across French and Swiss centers (1982–2017), long-term survival was outstanding: 97.8% at 1 year, 95.5% at 5 and 10 years, 92.0% at 15 years, and 89.1% at 20 years. Liver transplantation is curative for the hepatic component of AATD, as the donor liver produces normal M-AAT, correcting both the metabolic defect and the toxic gain-of-function mechanism. Graft survival was similarly excellent (81.5% at 20 years). These results establish liver transplantation as a definitive treatment option and benchmark against which emerging therapies must be measured.

Finding 4: RNAi Achieves Robust Z-AAT Knockdown in Humans

The first-in-human RNAi trial (ARC-AAT) demonstrated that hepatic-targeted RNA interference can achieve clinically meaningful reductions in circulating Z-AAT levels. At the 4 mg/kg dose, maximum serum AAT reductions of 76.1% in healthy volunteers and 78.8% in Pi*ZZ patients were achieved, with similar pharmacokinetics across groups and a favorable safety profile. This proof-of-concept finding has catalyzed development of next-generation RNAi therapeutics (fazirsiran/ARO-AAT) that offer the potential to reduce intrahepatic polymer load and prevent liver disease progression — addressing the gain-of-toxic-function mechanism that cannot be treated by augmentation therapy.

Finding 5: Alvelestat Demonstrates Oral NE Inhibition Efficacy

Two Phase 2 randomized controlled trials (ATALANTa and ASTRAEUS, n=161) demonstrated that alvelestat, an oral neutrophil elastase inhibitor, at 240 mg BID achieved >90% blood NE suppression and significantly reduced the disease activity biomarker Aa-Val360 (fibrinogen degradation product). The 120 mg dose suppressed NE but did not impact disease activity biomarkers, establishing a clear dose-response relationship. This oral therapy represents a potentially practice-changing advance, as it could provide convenient, daily protease-antiprotease rebalancing without the burden of weekly IV infusions required by augmentation therapy.

Mechanistic Model

    SERPINA1 Z Mutation (Glu342Lys)
              |
    AAT Protein Misfolding
         /          \
        /            \
   +-----------+              +-----------+
   |                                      |
    LOSS OF FUNCTION                    GAIN OF TOXIC FUNCTION
   |                                      |
    ER Retention (~85%)                   Polymer Formation
   |                                      |
    Reduced Serum AAT (10-15%)        Accumulation in Hepatocyte ER
   |                                      |
    Reduced NE Inhibition in Lung      ER Stress / UPR Activation
   |                            |         |         |
    Protease-Antiprotease              PERK     IRE1a    ATF6a
    Imbalance                       (suppressed)(suppressed)(active)
   |                                      |
    Elastin Degradation              JNK/c-Jun -> Increased SERPINA1
   |                          (Vicious Cycle)
    + Smoking/Pollution                           |
    + Infections                     ERAD + Autophagy (compensatory)
    + Neutrophil Recruitment                      |
   |                         If insufficient clearance:
   v                                      v
    PANACINAR EMPHYSEMA              HEPATOCYTE SENESCENCE
    (lower-lobe predominant)         (p21+, shortened telomeres)
   |                                      |
   v                                      v
    COPD / Respiratory              FIBROSIS -> CIRRHOSIS -> HCC
    Failure
   |                                      |
    Rx: Augmentation Therapy         Rx: RNAi / Liver Transplant
 Alvelestat                       mTOR/JNK Inhibitors
 Lung Transplant                  Chemical Chaperones

Evidence Base

Landmark and Key References

Citation Key Contribution
PMID: 27465791 Comprehensive review establishing SERPINA1 as causal gene with dual organ involvement
PMID: 28927525 Described dual loss-of-function and gain-of-toxic-function mechanisms as unique to AATD
PMID: 42075511 Detailed the protease-antiprotease imbalance and neutrophil elastase pathogenesis
PMID: 32726073 Linked polymer load to hepatocyte senescence, fibrosis, and mortality
PMID: 28752441 Elucidated liver disease pathophysiology cascade from polymers to cirrhosis/HCC
PMID: 33139195 Demonstrated 89% 20-year survival after liver transplantation for AATD
PMID: 29572094 First-in-human RNAi proof of concept showing ~78% Z-AAT knockdown
PMID: 40967767 Phase 2 RCT evidence for oral neutrophil elastase inhibitor alvelestat
PMID: 29070580 Established MZ heterozygotes at increased emphysema risk when smoking
PMID: 28073160 Identified JNK pathway as key driver of hepatic disease in AATD
PMID: 38336172 Comprehensive characterization of ERAD, autophagy, and lysosomal degradation in AATD
PMID: 35621045 Demonstrated UPR branch selectivity in Z-AAT hepatocytes
PMID: 42072628 Identified mTOR modulation as therapeutic strategy for liver disease
PMID: 10677536 Chemical chaperone 4-PBA proof of concept in PiZ mice
PMID: 41216004 Norwegian epidemiological data showing 6.2x mortality vs. general population

Limitations and Knowledge Gaps

  1. Underdiagnosis remains the central clinical challenge: ~90% of affected individuals are never diagnosed, leading to delayed treatment and preventable lung damage.

  2. Incomplete understanding of phenotypic variability: Why only a subset (~10–15%) of Pi*ZZ neonates develop cholestasis, and why some ZZ adults never develop significant lung or liver disease, remains unexplained. GWAS in AATD-specific populations has not yet been performed.

  3. No approved pharmacological therapy for liver disease: While RNAi and other approaches are in clinical trials, there is currently no drug approved for AATD-associated hepatic injury. Liver transplantation remains the only definitive treatment.

  4. Limited evidence for standard COPD therapies in AATD: Most COPD clinical trials exclude AATD patients, meaning that bronchodilators, ICS, and other treatments are used based on extrapolation rather than direct evidence.

  5. Polymer structure debate unresolved: Whether serpin polymers form via loop-sheet insertion or domain swapping remains debated, with implications for therapeutic targeting.

  6. Long-term RNAi safety unknown: While early clinical data are promising, the long-term effects of sustained hepatic SERPINA1 silencing — particularly the balance between reducing toxic gain-of-function vs. potentially further reducing already-low serum AAT — require longer follow-up.

  7. Newborn screening controversies: While technically feasible, the variable penetrance, potential psychosocial harms, and lack of childhood liver disease treatment make the risk-benefit ratio uncertain.

  8. Extrapulmonary/extrahepatic manifestations understudied: The roles of AATD in vasculitis, cholesteatoma, cardiovascular disease, and other conditions require further investigation.

Proposed Follow-up Actions

  1. Conduct AATD-specific GWAS for lung function and liver disease outcomes using large, well-characterized cohorts (e.g., AAT Genetic Modifiers Study, Alpha-1 Foundation Research Registry) to identify modifier loci and develop polygenic risk scores for disease stratification.

  2. Complete Phase 3 RNAi trials (fazirsiran) with liver fibrosis endpoints and long-term follow-up to establish efficacy and safety of hepatic SERPINA1 silencing for liver disease.

  3. Design combination therapy trials pairing RNAi (for liver) with augmentation therapy or alvelestat (for lung) to address both disease mechanisms simultaneously.

  4. Develop and validate non-invasive liver fibrosis biomarker panels (ELF, IGF-1, polymer-specific assays) for longitudinal monitoring and clinical trial endpoints.

  5. Implement structured newborn screening pilot programs with longitudinal follow-up, taking advantage of new legal protections (GINA, ACA) and emerging therapies to shift the risk-benefit calculation.

  6. Investigate mTOR and JNK pathway inhibitors in clinical trials for AATD liver disease, building on strong preclinical evidence.

  7. Establish standardized international registries with harmonized clinical data, biobanking, and longitudinal follow-up to enable natural history studies and clinical trial recruitment.

  8. Pursue single-cell and spatial transcriptomics studies of AATD liver and lung tissue to define cell-type-specific disease mechanisms and identify novel therapeutic targets.

Ontology Summary Table

Ontology Key Terms
MONDO MONDO:0011073 (alpha-1-antitrypsin deficiency)
HP HP:0002097 (Emphysema), HP:0006510 (COPD), HP:0001394 (Cirrhosis), HP:0001395 (Hepatic fibrosis), HP:0006260 (Neonatal cholestasis), HP:0002110 (Bronchiectasis), HP:0012490 (Panniculitis), HP:0001402 (Hepatocellular carcinoma)
GO (BP) GO:0010951 (neg reg of endopeptidase activity), GO:0006915 (apoptotic process), GO:0016236 (macroautophagy), GO:0036503 (ERAD pathway), GO:0030574 (collagen catabolic process), GO:0006986 (response to unfolded protein)
GO (CC) GO:0005783 (ER), GO:0005788 (ER lumen), GO:0005764 (lysosome), GO:0005615 (extracellular space)
CL CL:0000182 (hepatocyte), CL:0000775 (neutrophil), CL:0000583 (alveolar macrophage), CL:0002062/CL:0002063 (type I/II pneumocytes), CL:0000576 (monocyte)
UBERON UBERON:0002048 (lung), UBERON:0002107 (liver), UBERON:0002097 (skin)
CHEBI CHEBI:82557 (alpha-1-antitrypsin), CHEBI:75275 (neutrophil elastase)
MAXO MAXO:0001298 (augmentation therapy), MAXO:0001175 (organ transplantation), MAXO:0000079 (genetic counseling/testing), MAXO:0000502 (pulmonary rehabilitation)

Report generated: 2026-05-05. Based on systematic analysis of 79 peer-reviewed publications and structured disease ontology resources. This report is intended for disease knowledge base population and should be updated as new clinical trial data and mechanistic insights become available.