A chronic cholestatic liver disease characterized by inflammation and fibrosis of intrahepatic and extrahepatic bile ducts, leading to multifocal strictures and eventual biliary cirrhosis. Strongly associated with inflammatory bowel disease, particularly ulcerative colitis.
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name: Primary Sclerosing Cholangitis
creation_date: '2025-12-19T01:12:52Z'
updated_date: '2026-02-17T21:53:14Z'
category: Autoimmune
parents:
- Autoimmune Disease
- Liver Disease
disease_term:
preferred_term: Primary Sclerosing Cholangitis
term:
id: MONDO:0013433
label: primary sclerosing cholangitis
description: >-
A chronic cholestatic liver disease characterized by inflammation and fibrosis
of intrahepatic and extrahepatic bile ducts, leading to multifocal strictures
and eventual biliary cirrhosis. Strongly associated with inflammatory bowel
disease, particularly ulcerative colitis.
pathophysiology:
- name: Bile Duct Inflammation and Fibrosis
description: >-
Periductal inflammation with concentric fibrosis (onion-skinning) leads
to progressive stricture formation. Both innate and adaptive immune cells
infiltrate the bile duct epithelium.
cell_types:
- preferred_term: Fibroblast
term:
id: CL:0000057
label: fibroblast
biological_processes:
- preferred_term: Inflammatory Response
term:
id: GO:0006954
label: inflammatory response
evidence:
- reference: PMID:39250501
reference_title: "Central role for cholangiocyte pathobiology in cholestatic liver diseases."
supports: PARTIAL
snippet: >-
Cholangiopathies comprise a spectrum of chronic intrahepatic and extrahepatic
biliary tract disorders culminating in progressive cholestatic liver injury,
fibrosis, and often cirrhosis and its sequela.
explanation: >-
Demonstrates that PSC involves progressive fibrosis as a core pathological
feature of biliary tract disorders.
- reference: PMID:39250501
reference_title: "Central role for cholangiocyte pathobiology in cholestatic liver diseases."
supports: PARTIAL
snippet: >-
Herein, we review the pivotal role of cholangiocytes in cholestatic fibrogenesis,
focusing on the crosstalk between cholangiocytes and portal fibroblasts and
HSCs.
explanation: >-
Confirms the central role of fibroblast-cholangiocyte crosstalk in driving
periductal fibrosis in PSC.
- name: Gut-Liver Axis Dysregulation
description: >-
Aberrant homing of gut-primed lymphocytes to the liver through shared
adhesion molecules (MAdCAM-1, CCL25). Bacterial translocation and altered
bile acid metabolism contribute to hepatic inflammation.
cell_types:
- preferred_term: T Cell
term:
id: CL:0000084
label: T cell
biological_processes:
- preferred_term: Cell Migration
term:
id: GO:0016477
label: cell migration
evidence:
- reference: PMID:39250501
reference_title: "Central role for cholangiocyte pathobiology in cholestatic liver diseases."
supports: PARTIAL
snippet: >-
The crosstalk between cholangiocytes and cells of the innate (neutrophils
and macrophages) and adaptive (T cells and B cells) immune systems is also
examined in detail.
explanation: >-
Confirms the role of adaptive immune cells, particularly T cells, in the
pathogenesis of cholestatic liver diseases including PSC.
- name: Cholangiocyte Senescence
description: >-
Biliary epithelial cells undergo premature senescence with SASP (senescence-
associated secretory phenotype), promoting inflammation and fibrosis
through release of pro-inflammatory mediators.
biological_processes:
- preferred_term: Cellular Senescence
term:
id: GO:0090398
label: cellular senescence
evidence:
- reference: PMID:39250501
reference_title: "Central role for cholangiocyte pathobiology in cholestatic liver diseases."
supports: PARTIAL
snippet: >-
The proclivity of these cells to undergo a senescence-associated secretory
phenotype, which is proinflammatory and profibrogenic, and the intrinsic
intracellular activation pathways resulting in the secretion of cytokines
and chemokines are reviewed.
explanation: >-
Directly supports that cholangiocytes undergo senescence-associated secretory
phenotype that drives inflammation and fibrosis in cholestatic diseases.
phenotypes:
- name: Pruritus
category: Dermatological
frequency: FREQUENT
phenotype_term:
preferred_term: Pruritus
term:
id: HP:0000989
label: Pruritus
- name: Fatigue
category: Systemic
frequency: VERY_FREQUENT
phenotype_term:
preferred_term: Fatigue
term:
id: HP:0012378
label: Fatigue
- name: Jaundice
category: Hepatic
frequency: FREQUENT
phenotype_term:
preferred_term: Jaundice
term:
id: HP:0000952
label: Jaundice
- name: Abdominal Pain
category: Gastrointestinal
frequency: FREQUENT
phenotype_term:
preferred_term: Abdominal Pain
term:
id: HP:0002027
label: Abdominal pain
biochemical:
- name: Alkaline Phosphatase
presence: Elevated
context: Cholestatic pattern, often marked
evidence:
- reference: PMID:39250501
reference_title: "Central role for cholangiocyte pathobiology in cholestatic liver diseases."
supports: PARTIAL
snippet: >-
Cholangiopathies comprise a spectrum of chronic intrahepatic and extrahepatic
biliary tract disorders culminating in progressive cholestatic liver injury,
fibrosis, and often cirrhosis and its sequela.
explanation: >-
Cholestatic liver injury in PSC leads to characteristic elevation of
cholestatic enzymes including alkaline phosphatase.
- name: GGT
presence: Elevated
context: Correlates with cholestasis
- name: p-ANCA
presence: Variable
context: Present in 60-80% of patients
genetic:
- name: HLA-DRB1*03
association: Risk Factor
- name: HLA-B8
association: Risk Factor
environmental:
- name: Inflammatory Bowel Disease
notes: Present in 70-80% of patients, usually UC
treatments:
- name: Ursodeoxycholic Acid
description: May improve biochemistry but no proven survival benefit.
evidence:
- reference: PMID:39404413
reference_title: "Bile Acids-Based Therapies for Primary Sclerosing Cholangitis: Current Landscape and Future Developments."
supports: PARTIAL
snippet: >-
there is no evidence that the use of UDCA delays the time to liver transplant
or increases survival.
explanation: >-
Confirms that despite widespread use, UDCA lacks proven efficacy for
delaying transplantation or improving survival in PSC.
- name: Endoscopic Therapy
description: Balloon dilation for dominant strictures.
- name: Liver Transplantation
description: Only curative treatment; disease may recur.
evidence:
- reference: PMID:39250501
reference_title: "Central role for cholangiocyte pathobiology in cholestatic liver diseases."
supports: NO_EVIDENCE
snippet: >-
Treatment for these diseases is limited, and collectively, they are one of
the therapeutic "black boxes" in clinical hepatology.
explanation: >-
Highlights the limited treatment options for PSC, with transplantation
remaining the primary definitive therapy.
- name: Cholangiocarcinoma Surveillance
description: Regular imaging due to cancer risk.
clinical_trials:
- name: NCT06037577
phase: PHASE_I
description: Double-blind, randomized, placebo-controlled study assessing
safety, tolerability, pharmacokinetics, and pharmacodynamics of single
escalating subcutaneous doses of CM-101, an anti-fibrotic agent developed
for PSC.
evidence:
- reference: clinicaltrials:NCT06037577
supports: PARTIAL
snippet: CM-101 is developed as treatment for medical conditions involving
inflammatory and fibrotic mechanisms such as non-alcoholic steatohepatitis
(NASH) and primary sclerosing cholangitis (PSC) and systemic sclerosis
(SSc). In this current study, the IP is tested in healthy male volunteers.
explanation: This Phase I study characterizes CM-101, a candidate therapy
for PSC and related fibrotic diseases, establishing early human safety
data.
classifications:
harrisons_chapter:
- classification_value: liver disorder
- classification_value: autoimmune disease
references:
- reference: DOI:10.1016/j.lanepe.2024.101002
title: 'Past, current, and future trends in the prevalence of primary sclerosing
cholangitis and inflammatory bowel disease across England (2015–2027): a nationwide,
population-based study'
findings: []
- reference: DOI:10.1097/hep.0000000000001093
title: Central role for cholangiocyte pathobiology in cholestatic liver
diseases
findings: []
- reference: DOI:10.3390/cells13191650
title: 'Bile Acids-Based Therapies for Primary Sclerosing Cholangitis: Current Landscape
and Future Developments'
findings: []
- reference: DOI:10.3390/cells13231997
title: Molecular Mechanisms of Fibrosis in Cholestatic Liver Diseases and
Regenerative Medicine-Based Therapies
findings: []
Disease Pathophysiology Research Report
Target Disease - Disease Name: Primary Sclerosing Cholangitis (PSC) - MONDO ID: not specified (leave blank if unavailable in current context) - Category: Autoimmune (immune-mediated cholangiopathy)
Pathophysiology description Primary sclerosing cholangitis is a progressive, immune-mediated cholangiopathy characterized by chronic inflammation and fibro-obliterative scarring of intra- and/or extrahepatic bile ducts, culminating in cholestasis, biliary fibrosis, cirrhosis, and heightened risk of cholangiocarcinoma. Contemporary models integrate: (1) mucosal immune activation in the gut with lymphocyte homing to the liver via MAdCAM-1–α4β7 and other addressins; (2) cholangiocyte-intrinsic injury responses including epigenetically reinforced senescence and SASP that amplify inflammation and the ductular reaction (DR); (3) reciprocal crosstalk with portal fibroblasts and hepatic stellate cells (HSCs) driving periductal fibrosis; (4) dysregulated bile-acid receptor signaling (FXR–FGF19, GPBAR1/TGR5) and bicarbonate umbrella failure; and (5) a gut microbiome–bile acid axis that fosters dysbiosis, barrier dysfunction, bacterial translocation, and immune activation in the portal tract. PSC is polygenic with strong HLA signals and several non-HLA immune loci (e.g., IL2RA, MST1, SH2B3, BACH2, DCDC2), consistent with adaptive immune dysregulation intersecting with epithelial injury and cholestatic signaling (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 1-2, fiorucci2024bileacidsbasedtherapies pages 2-4, wang2024molecularmechanismsof pages 6-8).
1) Core Pathophysiology - Immune mechanisms: Inflamed hepatic sinusoidal endothelium expresses MAdCAM-1, recruiting α4β7+ gut-primed lymphocytes; innate activation (macrophages, dendritic cells, NK cells) promotes NF-κB/NLRP3-dependent cytokines (IL-6, IL-12, IL-1β, TNF-α) and Th1/Th17 responses, with portal CD4+ and lobular CD8+ infiltrates. This gut–liver homing axis is a defining feature of PSC immunobiology (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 2-4). - Unconventional T cells and cholangiocyte antigen presentation: Cholangiocytes upregulate MHC I/II under inflammation and can present non-peptide antigens via CD1d and MR1; “CD1d is downregulated in PSC and PBC,” and bile from PSC contains MAIT antigens; anti-MR1 blockade attenuates MAIT activation. MAIT cells can drive cholangiocyte proliferation via amphiregulin (AREG), indicating reciprocal epithelial–immune loops (Sep 2025; Hepatology; https://doi.org/10.1097/hep.0000000000001093) (jalansakrikar2025centralrolefor pages 17-18). - Cholangiocyte senescence and SASP: PSC shows accelerated cholangiocyte senescence, reduced tight junction ZO-1, and SASP mediators (e.g., IL-1β, IL-6, IL-8, CCL2, MMP3, PAI-1; SERPINE1, IGFBP5), with senescent burden correlating with severity. Epigenetic marks (H3K4me3 activation of CDKN2A; H3K9me3 silencing of TERT) reinforce senescence; cholangiocyte-selective TERT deficiency worsens fibrosis in vivo, while danazol can ameliorate fibrosis in Abcb4−/− mice (Sep 2025; Hepatology; https://doi.org/10.1097/hep.0000000000001093) and (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (jalansakrikar2025centralrolefor pages 6-7, fiorucci2024bileacidsbasedtherapies pages 4-5). - Ductular reaction and fibrogenic crosstalk: DRCs/ductular reaction cells expand and adopt a profibrotic, neutrophil-recruiting phenotype, secreting TNFα, IL-6, MCP-1, TGFβ. Portal fibroblasts (early responders near ducts) and HSCs (space of Disse) activate to ECM-producing myofibroblasts under cholangiokines and a stiffening matrix, creating a self-sustaining fibrogenic loop (Oct 2024; Cells; https://doi.org/10.3390/cells13191650; Sep 2025; Hepatology; https://doi.org/10.1097/hep.0000000000001093) (fiorucci2024bileacidsbasedtherapies pages 4-5, jalansakrikar2025centralrolefor pages 17-18, jalansakrikar2025centralrolefor pages 6-7). - Bile-acid receptor signaling: Altered bile-acid composition in PSC (↑ serum total, primary and conjugated BAs; higher primary:secondary ratio; lower fecal BAs in PSC-IBD) and impaired “bicarbonate umbrella” stress cholangiocytes. Dysregulated FXR–FGF19 signaling may suppress BA synthesis (low C4 prognostic of worse outcomes), suggesting caution with potent FXR/FGF19 agonism in advanced disease; GPBAR1/TGR5 signaling in cholangiocytes supports bicarbonate secretion and immune regulation and is reported downregulated in PSC (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 9-10, fiorucci2024bileacidsbasedtherapies pages 1-2). - Microbiome–bile acid axis and bacterial translocation: PSC exhibits consistent dysbiosis (↑ Enterococcus, Veillonella, Fusobacterium, Enterobacteriaceae, Streptococcus; ↓ Coprococcus, Blautia). Dysbiosis and mucosal barrier disruption promote PAMP translocation via the portal vein, activating hepatic APCs and perpetuating inflammation and fibrosis. Microbiome-directed interventions (e.g., vancomycin) have improved biochemical markers but lack proven disease-modifying effects (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 9-10, wang2024molecularmechanismsof pages 6-8).
2) Key Molecular Players - Genes/Proteins (HGNC): HLA class I/II (antigen presentation); IL2RA (HGNC:6008), MST1 (HGNC:7390; also known as MST1/HPN context varies across studies), SH2B3 (HGNC:30473), BACH2 (HGNC:935), DCDC2 (HGNC:22911). Polygenic risk supports immune regulation and lymphocyte signaling in PSC genetics (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) and OpenTargets PSC associations (EFO_0004268) (fiorucci2024bileacidsbasedtherapies pages 2-4). - Chemical entities (CHEBI, where applicable): Bile acids (cholic acid, chenodeoxycholic acid; CHEBI:36262/16755), ursodeoxycholic acid (CHEBI:9907), norursodeoxycholic acid, FGF19 analogs (aldafermin), FXR agonists (obeticholic acid; CHEBI:82775; cilofexor; tropifexor), ASBT/IBAT inhibitors (e.g., maralixibat), PPAR agonists (elafibranor, seladelpar) (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 1-2, fiorucci2024bileacidsbasedtherapies pages 10-11, fiorucci2024bileacidsbasedtherapies pages 26-27). - Cell types (CL): Cholangiocytes/biliary epithelial cells (CL:0002396), portal fibroblasts (CL:0002550; stromal myofibroblasts), hepatic stellate cells (CL:0000632), sinusoidal endothelial cells (CL:0002553), Kupffer cells/macrophages (CL:0000235), dendritic cells (CL:0000451), NK cells (CL:0000623), CD4+ and CD8+ T cells (CL:0000624/CL:0000625), MAIT cells (CL:0001064), iNKT cells (CL:0000814) (Sep 2025; Hepatology; https://doi.org/10.1097/hep.0000000000001093; Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (jalansakrikar2025centralrolefor pages 17-18, jalansakrikar2025centralrolefor pages 6-7, fiorucci2024bileacidsbasedtherapies pages 4-5, fiorucci2024bileacidsbasedtherapies pages 2-4). - Anatomical locations (UBERON): Intrahepatic and extrahepatic bile ducts (UBERON:0002394, UBERON:0002396), peribiliary glands (UBERON:0012684), portal tract (UBERON:0005912), liver sinusoid (UBERON:0001983), ileum/colon (UBERON:0002116/0001155) (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (wang2024molecularmechanismsof pages 6-8, fiorucci2024bileacidsbasedtherapies pages 4-5).
3) Biological Processes (candidate GO terms) - Immune cell trafficking and adhesion: lymphocyte homing (GO:0072678), integrin-mediated adhesion (GO:0007155), leukocyte transendothelial migration (GO:0072671) (mechanistic rationale via MAdCAM-1–α4β7) (fiorucci2024bileacidsbasedtherapies pages 2-4). - Antigen processing/presentation: MHC class I/II antigen processing (GO:0019882/GO:0019886); MR1- and CD1-mediated antigen presentation (GO:0042615 context), MAIT/iNKT activation (jalansakrikar2025centralrolefor pages 17-18). - Cellular senescence and SASP: cellular senescence (GO:0090398), regulation of cell cycle arrest (GO:0071156), cytokine-mediated signaling (GO:0019221), extracellular matrix organization (GO:0030198) (jalansakrikar2025centralrolefor pages 6-7, fiorucci2024bileacidsbasedtherapies pages 4-5). - Bile acid signaling and transport: response to bile acid (GO:0032865), FXR signaling pathway (curated pathway), FGF19 signaling (GO:0038167), GPBAR1/TGR5 signaling (GPCR signaling; GO:0007186), bile acid transport (GO:0015721) (fiorucci2024bileacidsbasedtherapies pages 9-10, fiorucci2024bileacidsbasedtherapies pages 1-2). - Microbiome–host interactions: response to molecule of bacterial origin (GO:0002237), NLRP3 inflammasome activation (GO:1900225) (fiorucci2024bileacidsbasedtherapies pages 2-4, wang2024molecularmechanismsof pages 6-8).
4) Cellular Components (GO CC) - Bile duct apical membrane and primary cilium (GO:0045177/GO:0005929) of cholangiocytes sensing bile flow/composition; plasma membrane and ciliary signaling hubs for TGR5/other receptors (fiorucci2024bileacidsbasedtherapies pages 4-5). - Extracellular space/ECM (GO:0005576/GO:0031012) where SASP cytokines/chemokines and matrix proteins accumulate; periductal ECM stiffening feeds forward on cholangiocyte phenotype (jalansakrikar2025centralrolefor pages 17-18). - Bile canaliculus/bile duct lumen (GO:0031253/GO:0034715), transporter-rich membranes (ASBT, BSEP, OSTα/β) (fiorucci2024bileacidsbasedtherapies pages 9-10).
5) Disease Progression - Initiation: Gut dysbiosis and mucosal inflammation with barrier dysfunction; PAMPs and microbially modified bile acids reach the liver via portal circulation, activating APCs and priming gut-homing lymphocytes that enter the biliary tree (wang2024molecularmechanismsof pages 6-8, fiorucci2024bileacidsbasedtherapies pages 2-4). - Propagation: Cholangiocyte stress from toxic bile acids and bicarbonate umbrella failure leads to epithelial injury, MHC I/II upregulation, and antigen presentation (MR1/CD1d) to MAIT/NKT cells; senescence with SASP reinforces leukocyte recruitment (jalansakrikar2025centralrolefor pages 17-18, fiorucci2024bileacidsbasedtherapies pages 4-5, jalansakrikar2025centralrolefor pages 6-7). - Fibrogenesis: Ductular reaction expansion and cholangiokine production drive portal fibroblast and HSC activation and ECM deposition, with matrix stiffness further promoting cholangiocyte pro-fibrotic programming (jalansakrikar2025centralrolefor pages 17-18, fiorucci2024bileacidsbasedtherapies pages 4-5). - Clinical manifestations: Progressive cholestasis and fibrosis; high transplant need over 12–20 years in a substantial fraction of patients; cholangiocarcinoma risk accrues (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 1-2, fiorucci2024bileacidsbasedtherapies pages 2-4).
6) Phenotypic Manifestations (HP terms) - Cholestatic liver enzyme elevation: elevated alkaline phosphatase (HP:0003155) (fiorucci2024bileacidsbasedtherapies pages 1-2). - Pruritus (HP:0000989) linked to bile-acid signaling; mechanistic work implicates pruritogens and BA receptors (fiorucci2024bileacidsbasedtherapies pages 26-27). - Fatigue (HP:0012378) and jaundice (HP:0000952) with cholestasis; progressive biliary fibrosis/cirrhosis (HP:0001394) (fiorucci2024bileacidsbasedtherapies pages 1-2). - PSC-IBD: coexisting ulcerative colitis/Crohn disease with increased PSC-IBD burden in population studies (Sep 2024; Lancet Reg Health Eur; https://doi.org/10.1016/j.lanepe.2024.101002) (fiorucci2024bileacidsbasedtherapies pages 10-11). - Cancer risk: increased cholangiocarcinoma risk (range often cited ~10–15% over lifetime in reviews), concordant with progressive periductal inflammation/fibrosis (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 1-2).
Recent developments and latest research (2023–2024 priority) - Epidemiology and PSC–IBD: A nationwide analysis across England (2015–2027) shows rising PSC-IBD prevalence with implications for transplant units (Sep 2024; Lancet Regional Health – Europe; https://doi.org/10.1016/j.lanepe.2024.101002) (fiorucci2024bileacidsbasedtherapies pages 10-11). - Noninvasive fibrosis monitoring and risk models: Machine-learning PReSTo and liver stiffness thresholds via TE/MRE are being adopted; annual TE increase >1.3 kPa predicts worse transplant-free survival; however, no therapy has yet shown fibrosis reduction by LSM in trials (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 10-11). - Microbiome–bile acid axis: PSC shows reproducible dysbiosis and altered bile-acid pools. Lower serum C4 (suppressed BA synthesis) predicts adverse outcomes; fecal bile acids reduced in PSC-IBD. These data caution about strong FXR–FGF19 suppression in advanced PSC (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 9-10). - Immunobiology: High-resolution views emphasize tissue residency and unconventional T cell circuits engaging cholangiocytes (MR1/CD1d), with bile-borne antigens activating MAIT biology; extracellular matrix stiffness as a microenvironmental cue for cholangiocyte inflammatory/fibrogenic programming (Sep 2025; Hepatology; https://doi.org/10.1097/hep.0000000000001093) (jalansakrikar2025centralrolefor pages 17-18).
Current applications and real-world implementations - Clinical management: MRCP-first diagnosis; supportive care with UDCA variably used despite lack of proven survival/transplant benefit; transplant for end-stage disease; surveillance for cholangiocarcinoma and colorectal cancer in PSC-IBD; use of TE/MRE and risk models (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 1-2, fiorucci2024bileacidsbasedtherapies pages 10-11). - Microbiome-directed therapy: Oral vancomycin or other antibiotics can improve biochemistry and risk scores in some series, but durability and impact on progression remain unproven (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 9-10).
Expert opinions and analysis (authoritative sources) - “The mechanistic involvement of the gut in PSC remains ambiguous,” yet gut microbial metabolites and BA signaling via FXR/GPBAR1 are central candidates; “lower C4 levels… are associated with worse clinical outcomes,” advising caution with strong FXR–FGF19 suppression in advanced disease (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 10-11, fiorucci2024bileacidsbasedtherapies pages 9-10). - Cholangiocytes function as an immunologic hub capable of antigen presentation to unconventional T cells, and ECM stiffness actively drives their profibrotic program; better definition of cholangiocyte senescence and death modalities is a key research priority (Sep 2025; Hepatology; https://doi.org/10.1097/hep.0000000000001093) (jalansakrikar2025centralrolefor pages 17-18).
Relevant statistics and data - Incidence/prevalence: Reviews summarize incidence ~1–1.5 per 100,000 person-years and prevalence ~6–16 per 100,000; male predominance; strong PSC–IBD association (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 1-2). - PSC–IBD frequency: 60–80% of PSC patients have IBD (predominantly UC); 5–10% of UC patients have PSC (Dec 2024; Cells; https://doi.org/10.3390/cells13231997) (wang2024molecularmechanismsof pages 6-8). - Progression: About 40% of patients ultimately undergo liver transplantation; typical time to transplant ~12–20 years (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 1-2, fiorucci2024bileacidsbasedtherapies pages 2-4). - Bile-acid synthesis marker C4: Lower C4 associates with higher risk of transplant or death; UDCA did not change C4 (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 9-10).
Gene/protein annotations with ontology terms (examples) - IL2RA (HGNC:6008): T cell activation, immune tolerance (GO:0042110; GO:0006955); genetic association in PSC (Oct 2024; Cells) (fiorucci2024bileacidsbasedtherapies pages 2-4). - MST1 (HGNC:7390): Immune cell trafficking/adhesion; PSC association (Oct 2024; Cells) (fiorucci2024bileacidsbasedtherapies pages 2-4). - SH2B3 (HGNC:30473), BACH2 (HGNC:935), DCDC2 (HGNC:22911): Immune regulation and cholangiocyte/microtubule biology implicated via GWAS/association (Oct 2024; Cells) (fiorucci2024bileacidsbasedtherapies pages 2-4). - FXR/NR1H4 (HGNC:7965), GPBAR1/TGR5 (HGNC:18174): Bile acid receptor signaling in hepatobiliary and immune cells (GO:0009755; GO:0007186) (fiorucci2024bileacidsbasedtherapies pages 9-10, fiorucci2024bileacidsbasedtherapies pages 1-2).
Cell type involvement (CL terms) - Cholangiocytes (CL:0002396), portal fibroblasts (CL:0002550), hepatic stellate cells (CL:0000632), Kupffer cells/macrophages (CL:0000235), dendritic cells (CL:0000451), MAIT cells (CL:0001064), iNKT cells (CL:0000814), CD4+ and CD8+ T cells (CL:0000624/CL:0000625), sinusoidal endothelial cells (CL:0002553) (jalansakrikar2025centralrolefor pages 17-18, fiorucci2024bileacidsbasedtherapies pages 4-5, fiorucci2024bileacidsbasedtherapies pages 2-4).
Anatomical locations (UBERON terms) - Bile ducts (UBERON:0002394/0002396), peribiliary glands (UBERON:0012684), portal tract (UBERON:0005912), liver sinusoids (UBERON:0001983), ileum/colon (UBERON:0002116/0001155) (wang2024molecularmechanismsof pages 6-8, fiorucci2024bileacidsbasedtherapies pages 4-5).
Chemical entities (CHEBI terms, examples) - Ursodeoxycholic acid (CHEBI:9907), cholic acid (CHEBI:36262), chenodeoxycholic acid (CHEBI:16755), obeticholic acid (CHEBI:82775), maralixibat (ASBT inhibitor), aldafermin (FGF19 analog), cilofexor/tropifexor (FXR agonists), elafibranor/seladelpar (PPAR agonists) (fiorucci2024bileacidsbasedtherapies pages 1-2, fiorucci2024bileacidsbasedtherapies pages 26-27, fiorucci2024bileacidsbasedtherapies pages 10-11).
Evidence items (with URLs/dates) - Fiorucci et al., Bile Acids-Based Therapies for PSC: Current Landscape and Future Developments. Cells. Published Oct 4, 2024. DOI: 10.3390/cells13191650; URL: https://doi.org/10.3390/cells13191650 (fiorucci2024bileacidsbasedtherapies pages 2-4, fiorucci2024bileacidsbasedtherapies pages 9-10, fiorucci2024bileacidsbasedtherapies pages 1-2, fiorucci2024bileacidsbasedtherapies pages 4-5, fiorucci2024bileacidsbasedtherapies pages 26-27, fiorucci2024bileacidsbasedtherapies pages 10-11). - Wang et al., Molecular Mechanisms of Fibrosis in Cholestatic Liver Diseases and Regenerative Medicine-Based Therapies. Cells. Dec 2024. DOI: 10.3390/cells13231997; URL: https://doi.org/10.3390/cells13231997 (psc–ibd statistics, gut–liver axis) (wang2024molecularmechanismsof pages 6-8). - Jalan-Sakrikar et al., Central role for cholangiocyte pathobiology in cholestatic liver diseases. Hepatology. Sep 2025. DOI: 10.1097/hep.0000000000001093; URL: https://doi.org/10.1097/hep.0000000000001093 (MAIT/CD1d/MR1; epigenetic-senescence; ECM stiffness; DR) (jalansakrikar2025centralrolefor pages 17-18, jalansakrikar2025centralrolefor pages 6-7). - Crothers et al., Past, current, and future trends in the prevalence of PSC and IBD across England (2015–2027). Lancet Regional Health – Europe. Sep 2024. DOI: 10.1016/j.lanepe.2024.101002; URL: https://doi.org/10.1016/j.lanepe.2024.101002 (fiorucci2024bileacidsbasedtherapies pages 10-11).
Candidate therapeutics and outcomes (selected) - UDCA: Widely used, but no evidence of delayed transplant or survival benefit in PSC (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 1-2). - FXR agonists: Obeticholic acid, cilofexor, tropifexor under investigation in PSC; caution that FXR–FGF19 axis can suppress BA synthesis, and lower C4 correlates with worse outcomes, especially in advanced disease (Oct 2024; Cells; https://doi.org/10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 9-10, fiorucci2024bileacidsbasedtherapies pages 10-11). - FGF19 analogs: Aldafermin suppresses hydrophobic BAs in cholestasis and is being explored across cholestatic diseases (e.g., JHEP Rep. 2021, referenced within review) (fiorucci2024bileacidsbasedtherapies pages 26-27). - ASBT/IBAT inhibitors: Maralixibat has been piloted (Hepatology Communications 2023) with biochemical effects; class continues in evaluation for PSC (fiorucci2024bileacidsbasedtherapies pages 26-27, fiorucci2024bileacidsbasedtherapies pages 10-11). - PPAR agonists: Elafibranor and seladelpar are being evaluated in cholestatic disease contexts; mechanistic rationale via anti-inflammatory and metabolic pathways (fiorucci2024bileacidsbasedtherapies pages 1-2, fiorucci2024bileacidsbasedtherapies pages 10-11). - norUDCA: Harnesses cholehepatic shunting; part of the bile-acid–centric therapeutic armamentarium under study in PSC (fiorucci2024bileacidsbasedtherapies pages 10-11).
Direct supporting quotes - “Activation of the liver immune system by intestinal antigens… leading to NF-κB- and NLRP3-dependent generation of cytokines… including IL-6, IL-12, IL-1β, and TNF-α” (Oct 2024; Cells; DOI 10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 2-4). - “Lower C4 levels, indicating suppressed bile acid synthesis, are associated with worse clinical outcomes… UDCA did not change C4” (Oct 2024; Cells; DOI 10.3390/cells13191650) (fiorucci2024bileacidsbasedtherapies pages 9-10). - “CD1d is downregulated in PSC and PBC… bile from PSC patients contains MAIT antigens… anti-MR1 blocking antibody attenuated activation of MAIT cells” (Sep 2025; Hepatology; DOI 10.1097/hep.0000000000001093) (jalansakrikar2025centralrolefor pages 17-18).
Limitations Where possible, 2023–2024 sources were prioritized; several authoritative mechanistic insights (MAIT/CD1d/MR1 and epigenetic–senescence programs) derive from a 2025 Hepatology review synthesizing recent primary studies, included here due to its comprehensive, expert nature and lack of equally detailed 2023–2024 alternatives in the current evidence set (jalansakrikar2025centralrolefor pages 17-18, jalansakrikar2025centralrolefor pages 6-7).
Summary PSC pathogenesis arises from convergent immune, epithelial, stromal, and bile-acid–microbiome mechanisms. Gut-primed lymphocytes home to the liver; cholangiocytes enact immune and senescence programs reinforced by epigenetic remodeling; ductular reaction and portal mesenchyme crosstalk drive periductal fibrosis; and altered bile-acid receptor signaling intersects with dysbiosis to perpetuate injury. Genetic predisposition in HLA and non-HLA immune loci frames susceptibility. Therapeutics target bile-acid pathways (FXR–FGF19, TGR5, ASBT), metabolic and inflammatory axes (PPAR), and microbiome modulation, with ongoing efforts to align mechanism with disease stage to avoid deleterious over-suppression of BA synthesis in advanced disease (fiorucci2024bileacidsbasedtherapies pages 9-10, fiorucci2024bileacidsbasedtherapies pages 1-2, fiorucci2024bileacidsbasedtherapies pages 2-4, fiorucci2024bileacidsbasedtherapies pages 10-11, jalansakrikar2025centralrolefor pages 17-18).
References
(fiorucci2024bileacidsbasedtherapies pages 1-2): Stefano Fiorucci, Ginevra Urbani, Cristina Di Giorgio, Michele Biagioli, and Eleonora Distrutti. Bile acids-based therapies for primary sclerosing cholangitis: current landscape and future developments. Cells, 13:1650, Oct 2024. URL: https://doi.org/10.3390/cells13191650, doi:10.3390/cells13191650. This article has 10 citations and is from a poor quality or predatory journal.
(fiorucci2024bileacidsbasedtherapies pages 2-4): Stefano Fiorucci, Ginevra Urbani, Cristina Di Giorgio, Michele Biagioli, and Eleonora Distrutti. Bile acids-based therapies for primary sclerosing cholangitis: current landscape and future developments. Cells, 13:1650, Oct 2024. URL: https://doi.org/10.3390/cells13191650, doi:10.3390/cells13191650. This article has 10 citations and is from a poor quality or predatory journal.
(wang2024molecularmechanismsof pages 6-8): Wei-Lu Wang, Haoran Lian, Yingyu Liang, Yongqin Ye, Paul Kwong Hang Tam, and Yan Chen. Molecular mechanisms of fibrosis in cholestatic liver diseases and regenerative medicine-based therapies. Cells, 13:1997, Dec 2024. URL: https://doi.org/10.3390/cells13231997, doi:10.3390/cells13231997. This article has 5 citations and is from a poor quality or predatory journal.
(jalansakrikar2025centralrolefor pages 17-18): Nidhi Jalan-Sakrikar, Maria Eugenia Guicciardi, Steven P. O’Hara, Adiba Azad, Nicholas F. LaRusso, Gregory J. Gores, and Robert C. Huebert. Central role for cholangiocyte pathobiology in cholestatic liver diseases. Hepatology, Sep 2025. URL: https://doi.org/10.1097/hep.0000000000001093, doi:10.1097/hep.0000000000001093. This article has 20 citations and is from a highest quality peer-reviewed journal.
(jalansakrikar2025centralrolefor pages 6-7): Nidhi Jalan-Sakrikar, Maria Eugenia Guicciardi, Steven P. O’Hara, Adiba Azad, Nicholas F. LaRusso, Gregory J. Gores, and Robert C. Huebert. Central role for cholangiocyte pathobiology in cholestatic liver diseases. Hepatology, Sep 2025. URL: https://doi.org/10.1097/hep.0000000000001093, doi:10.1097/hep.0000000000001093. This article has 20 citations and is from a highest quality peer-reviewed journal.
(fiorucci2024bileacidsbasedtherapies pages 4-5): Stefano Fiorucci, Ginevra Urbani, Cristina Di Giorgio, Michele Biagioli, and Eleonora Distrutti. Bile acids-based therapies for primary sclerosing cholangitis: current landscape and future developments. Cells, 13:1650, Oct 2024. URL: https://doi.org/10.3390/cells13191650, doi:10.3390/cells13191650. This article has 10 citations and is from a poor quality or predatory journal.
(fiorucci2024bileacidsbasedtherapies pages 9-10): Stefano Fiorucci, Ginevra Urbani, Cristina Di Giorgio, Michele Biagioli, and Eleonora Distrutti. Bile acids-based therapies for primary sclerosing cholangitis: current landscape and future developments. Cells, 13:1650, Oct 2024. URL: https://doi.org/10.3390/cells13191650, doi:10.3390/cells13191650. This article has 10 citations and is from a poor quality or predatory journal.
(fiorucci2024bileacidsbasedtherapies pages 10-11): Stefano Fiorucci, Ginevra Urbani, Cristina Di Giorgio, Michele Biagioli, and Eleonora Distrutti. Bile acids-based therapies for primary sclerosing cholangitis: current landscape and future developments. Cells, 13:1650, Oct 2024. URL: https://doi.org/10.3390/cells13191650, doi:10.3390/cells13191650. This article has 10 citations and is from a poor quality or predatory journal.
(fiorucci2024bileacidsbasedtherapies pages 26-27): Stefano Fiorucci, Ginevra Urbani, Cristina Di Giorgio, Michele Biagioli, and Eleonora Distrutti. Bile acids-based therapies for primary sclerosing cholangitis: current landscape and future developments. Cells, 13:1650, Oct 2024. URL: https://doi.org/10.3390/cells13191650, doi:10.3390/cells13191650. This article has 10 citations and is from a poor quality or predatory journal.