Bacillary Angiomatosis

Infectious Disease MONDO:0000758 Pathograph 22 Show in embeddings browser bartonellosis angiomatosis skin disease caused by bacterial infection

Bacillary angiomatosis is a Bartonella-driven vasoproliferative infection characterized by tumor-like capillary lesions of the skin, subcutaneous tissue, liver, spleen, bone, and other viscera, chiefly in immunocompromised hosts.

Ask OpenScientist

Ask a research question about Bacillary Angiomatosis. OpenScientist will conduct autonomous deep research using the Disorder Mechanisms Knowledge Base and PubMed literature (typically 10-30 minutes).

Submitting...

Do not include personal health information in your question. Questions and results are cached in your browser's local storage.

7
Pathophys.
10
Phenotypes
22
Pathograph
3
Medical Actions
9
References
1
Deep Research
⚙

Pathophysiology

7
Bartonella Infection in Immunocompromised Host
B. henselae or B. quintana reaches tissue in a host whose immune suppression permits Bartonella infection to progress into bacillary angiomatosis rather than remaining a contained lymphadenitic infection.
biological process involved in interaction with host GO:0051701 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves biological process involved in interaction with host (GO:0051701). GO:0051701 is a biological process from the Gene Ontology.
Downstream
Bartonella Angiogenic VEGFR2 Signaling Infected tissue exposes endothelial cells to Bartonella angiogenic factors.
Bartonella Intracellular Persistence Bartonella infection includes host-cell-associated bacterial niches that motivate intracellularly active antibacterial therapy.
Bartonella Ribosomal Translation Bacillary angiomatosis depends on living Bartonella with active bacterial ribosomal protein synthesis.
Fever Systemic Bartonella infection can present with fever.
Lymphadenopathy Systemic Bartonella disease may include lymph-node enlargement.
Anemia Disseminated B. henselae disease can include anemia in advanced HIV.
BadA-Mediated Endothelial Adhesion and VEGF Secretion B. henselae BadA supports endothelial adhesion and proangiogenic VEGF secretion.
VirB/D4 Bep Endothelial Survival Signaling VirB/D4-secreted Bep effectors separately inhibit endothelial apoptosis and induce angiogenic reprogramming.
Show evidence (1 reference)
PMID:24933445 SUPPORT REVIEW SYNTHESIS Human Clinical
"Clinical manifestations can range from benign and self-limited to severe and life-threatening disease."
The Bartonella pathogenicity review supports a host-context-dependent clinical spectrum from benign to severe disease.
Bartonella Angiogenic VEGFR2 Signaling
Bartonella BafA acts as a pro-angiogenic autotransporter whose passenger domain activates VEGF receptor 2 signaling, stimulating endothelial proliferation and angiogenesis.
endothelial cell CL:0000115 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves endothelial cell (CL:0000115). CL:0000115 is a cell type from the Cell Ontology.
vascular endothelial growth factor receptor signaling pathway GO:0048010 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased vascular endothelial growth factor receptor signaling pathway (GO:0048010). GO:0048010 is a biological process from the Gene Ontology. ↑ INCREASED angiogenesis GO:0001525 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased angiogenesis (GO:0001525). GO:0001525 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Lobular Capillary Proliferation VEGFR2-dependent angiogenic signaling drives capillary endothelial proliferation.
Show evidence (1 reference)
PMID:32678094 SUPPORT In Vitro
"BafA interacts with vascular endothelial growth factor (VEGF) receptor-2 and activates the downstream signaling pathway, suggesting that BafA functions as a VEGF analog."
Identifies BafA as a Bartonella VEGFR2-activating ligand, the upstream signal driving endothelial angiogenesis in this node.
BadA-Mediated Endothelial Adhesion and VEGF Secretion
Bartonella henselae BadA supports endothelial adhesion, extracellular-matrix binding, and HIF-1-dependent VEGF secretion that separately prime infected endothelium for angioproliferation.
endothelial cell CL:0000115 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves endothelial cell (CL:0000115). CL:0000115 is a cell type from the Cell Ontology.
cell adhesion GO:0007155 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased cell adhesion (GO:0007155). GO:0007155 is a biological process from the Gene Ontology. ↑ INCREASED angiogenesis GO:0001525 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased angiogenesis (GO:0001525). GO:0001525 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Lobular Capillary Proliferation BadA-dependent adhesion and VEGF secretion promote the endothelial proliferation that forms bacillary angiomas.
Show evidence (1 reference)
PMID:18627378 SUPPORT In Vitro
"Expression of Bartonella adhesin A (BadA) is crucial for bacterial autoagglutination, adhesion to host cells, binding to extracellular matrix proteins and proangiogenic reprogramming via activation of hypoxia inducible factor (HIF)-1."
B. henselae endothelial-cell experiments link BadA itself to host-cell adhesion and HIF-1-mediated angiogenic reprogramming.
VirB/D4 Bep Endothelial Survival Signaling
Bartonella henselae VirB/D4 translocates Bep effector proteins that drive invasome uptake, inhibit endothelial apoptosis, and activate an angiogenic phenotype independently of dense BadA expression.
endothelial cell CL:0000115 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves endothelial cell (CL:0000115). CL:0000115 is a cell type from the Cell Ontology.
negative regulation of apoptotic process GO:0043066 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased negative regulation of apoptotic process (GO:0043066). GO:0043066 is a biological process from the Gene Ontology. ↑ INCREASED angiogenesis GO:0001525 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased angiogenesis (GO:0001525). GO:0001525 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Lobular Capillary Proliferation VirB/D4-dependent endothelial survival and angiogenic reprogramming amplify capillary proliferation in bacillary angiomas.
Show evidence (1 reference)
PMID:23163798 SUPPORT BACKGROUND In Vitro
"VirB/D4 translocates several Bartonella effector proteins (Beps) into the cytoplasm of infected ECs, resulting, e.g. in uptake of bacterial aggregates via the invasome structure, inhibition of apoptosis and activation of a proangiogenic phenotype."
The paper's opening summary of prior endothelial-cell work supports modelling VirB/D4 Bep translocation as a pro-survival angiogenic branch; the node is separated from BadA because this study found that dense BadA interferes with VirB/D4-dependent effector translocation.
Lobular Capillary Proliferation
Bartonella-driven endothelial signaling expands irregular dermal and visceral capillaries into nodular lobular proliferations with a mixed inflammatory stromal infiltrate and extracellular bacterial aggregates.
endothelial cell CL:0000115 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves endothelial cell (CL:0000115). CL:0000115 is a cell type from the Cell Ontology.
angiogenesis GO:0001525 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased angiogenesis (GO:0001525). GO:0001525 is a biological process from the Gene Ontology. ↑ INCREASED inflammatory response GO:0006954 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased inflammatory response (GO:0006954). GO:0006954 is a biological process from the Gene Ontology. ↑ INCREASED
skin UBERON:0002097 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in skin, annotated with skin of body (UBERON:0002097). UBERON:0002097 is an anatomical location from the Uberon multi-species anatomy ontology. liver UBERON:0002107 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in liver (UBERON:0002107). UBERON:0002107 is an anatomical location from the Uberon multi-species anatomy ontology. spleen UBERON:0002106 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in spleen (UBERON:0002106). UBERON:0002106 is an anatomical location from the Uberon multi-species anatomy ontology.
Downstream
Cutaneous Vascular Papules and Nodules Lobular vascular growth in the skin presents as angiomatous papules and subcutaneous nodules.
Papules Cutaneous capillary proliferation presents as papular lesions.
Subcutaneous Nodules Deeper lobular proliferations can present as subcutaneous nodules.
Hepatosplenic Involvement Lesion dissemination to liver and spleen produces hepatosplenic bacillary disease.
Splenic Lesions Disseminated angioproliferative Bartonella lesions can involve the spleen.
Peliosis Hepatis B. henselae-associated bacillary angiomatosis-peliosis can form blood-filled peliotic lesions in the liver.
Lytic Bone Lesions Disseminated bacillary angiomatosis can produce long-bone destructive lesions.
Show evidence (1 reference)
PMID:24718378 SUPPORT Human Clinical
"Histologic examination by dermatopathologists in the United States revealed nodular dermal proliferations of irregular capillaries lined by spindled to epithelioid endothelial cells."
Histopathology from clinically suspected Kaposi sarcoma cases establishes the capillary endothelial proliferation that defines bacillary angiomatosis lesions.
Bartonella Intracellular Persistence
Bartonella species can occupy host-cell niches, so treatment of angioproliferative Bartonella infection favors agents such as macrolides and doxycycline that penetrate eukaryotic cells.
biological process involved in interaction with host GO:0051701 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves biological process involved in interaction with host (GO:0051701). GO:0051701 is a biological process from the Gene Ontology.
Show evidence (1 reference)
PMID:21557057 SUPPORT REVIEW SYNTHESIS In Vitro
"The ability to cause vasculoproliferative disorders and intraerythrocytic bacteraemia are unique features of the genus Bartonella."
Bartonella can occupy host-cell-associated niches, supporting intracellular activity as a treatment-relevant mechanism anchor.
Bartonella Ribosomal Translation
B. henselae and B. quintana require bacterial 70S ribosomal translation; erythromycin and doxycycline act on bacterial protein synthesis during prolonged therapy for bacillary angiomatosis.
translation GO:0006412 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves translation (GO:0006412). GO:0006412 is a biological process from the Gene Ontology.
Show evidence (1 reference)
PMID:24933445 SUPPORT REVIEW SYNTHESIS Human Clinical
"erythromycin is the first-line antibiotic therapy for the treatment of angioproliferative lesions."
Macrolide treatment of Bartonella angioproliferative lesions supports the bacterial ribosome as a therapy anchor for bacillary angiomatosis.
⬡

Pathograph

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

Phenotypes

10
Blood 1
Anemia HP:0001903 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Anemia (HP:0001903). HP:0001903 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:18098054 SUPPORT PRIMARY RESULT Human Clinical
"The authors report the case of an AIDS patient with bacillary angiomatosis, who had concurrent severe anemia, hepatitis, peritonitis, pleuritis, and pericarditis."
B. henselae bacillary angiomatosis in AIDS presented with concurrent severe anemia in this clinical case.
Cardiovascular 2
Cutaneous Vascular Papules and Nodules Vascular skin abnormality HP:0011276 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Vascular skin abnormality (HP:0011276). HP:0011276 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:11362939 SUPPORT REVIEW SYNTHESIS Human Clinical
"Lesions may affect almost any organ, and appear as angiomatous papules, dry scaling lesions, subcutaneous nodules, cellulitic plaques or deep, highly vascularized, soft tissue masses."
Review evidence for the core angiomatous papules, subcutaneous nodules, plaques, and soft-tissue masses that define cutaneous bacillary angiomatosis.
Lymphadenopathy HP:0002716 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Lymphadenopathy (HP:0002716). HP:0002716 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:22316326 SUPPORT REVIEW SYNTHESIS Human Clinical
"BA manifests on the skin with violaceous lesions mimicking Kaposi sarcoma, and is associated with fever, lymphadenopathy, and liver, spleen, or lung nodules."
Organ-transplant-recipient case review identifies lymphadenopathy as an associated bacillary angiomatosis manifestation.
Integument 2
Papules HP:0200034 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Papule (HP:0200034). HP:0200034 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:11362939 SUPPORT REVIEW SYNTHESIS Human Clinical
"Lesions may affect almost any organ, and appear as angiomatous papules, dry scaling lesions, subcutaneous nodules, cellulitic plaques or deep, highly vascularized, soft tissue masses."
The review specifically lists angiomatous papules as a lesion morphology.
Subcutaneous Nodules Skin nodule HP:0200036 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Skin nodule (HP:0200036). HP:0200036 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:11362939 SUPPORT REVIEW SYNTHESIS Human Clinical
"Lesions may affect almost any organ, and appear as angiomatous papules, dry scaling lesions, subcutaneous nodules, cellulitic plaques or deep, highly vascularized, soft tissue masses."
The review specifically lists subcutaneous nodules as a lesion morphology.
Metabolism 1
Fever HP:0001945 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Fever (HP:0001945). HP:0001945 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:10718405 SUPPORT REVIEW SYNTHESIS Human Clinical
"Multiple cutaneous nodular lesions together with fever, chills, malaise, anorexia, vomiting and headache are the most important clinical manifestations."
Review synthesis lists fever among the important manifestations of bacillary angiomatosis.
Musculoskeletal 1
Lytic Bone Lesions Osteolysis HP:0002797 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Osteolysis (HP:0002797). HP:0002797 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:9407154 SUPPORT Human Clinical
"Subcutaneous and lytic bone lesions were strongly associated with B. quintana, whereas peliosis hepatis was associated exclusively with B. henselae."
Molecularly speciated case-control data link lytic bone lesions with B. quintana bacillary angiomatosis-peliosis.
Other 3
Hepatosplenic Involvement
Show evidence (1 reference)
PMID:11362939 SUPPORT REVIEW SYNTHESIS Human Clinical
"Patients may have osseus BA lesions (frequently affecting the long bones); hepatic and/or splenic lesions; bacteremia; or endocarditis."
The review supports hepatic and splenic bacillary angiomatosis lesions.
Splenic Lesions
Show evidence (1 reference)
PMID:11362939 SUPPORT REVIEW SYNTHESIS Human Clinical
"Patients may have osseus BA lesions (frequently affecting the long bones); hepatic and/or splenic lesions; bacteremia; or endocarditis."
The review supports splenic involvement in bacillary angiomatosis.
Peliosis Hepatis
Show evidence (1 reference)
PMID:9407154 SUPPORT Human Clinical
"Subcutaneous and lytic bone lesions were strongly associated with B. quintana, whereas peliosis hepatis was associated exclusively with B. henselae."
Molecularly speciated bacillary angiomatosis-peliosis cases tie peliosis hepatis specifically to B. henselae.
💊

Medical Actions

3
Prolonged Macrolide or Tetracycline 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
Agent: erythromycin CHEBI:48923 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses erythromycin (CHEBI:48923). CHEBI:48923 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. azithromycin CHEBI:2955 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses azithromycin (CHEBI:2955). CHEBI:2955 is a therapeutic agent from Chemical Entities of Biological Interest. clarithromycin CHEBI:3732 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses clarithromycin (CHEBI:3732). CHEBI:3732 is a therapeutic agent from Chemical Entities of Biological Interest.
Platform: Small molecule
Prolonged macrolide or tetracycline therapy treats angioproliferative Bartonella lesions, with erythromycin as a first-line agent, doxycycline as an alternative, and azithromycin or clarithromycin as reported macrolide options.
Mechanism Target:
Bartonella Intracellular Persistence — Macrolides and tetracyclines reach the host-cell compartment where Bartonella can persist.
Bartonella Ribosomal Translation — Erythromycin and doxycycline suppress Bartonella protein synthesis through the bacterial ribosome.
Show evidence (4 references)
PMID:11362939 SUPPORT REVIEW SYNTHESIS Human Clinical
"Treatment with erythromycin for at least three months is recommended, or with doxycycline if erythromycin is not well-tolerated."
Review guidance supports prolonged erythromycin, or doxycycline as an alternative, for Bartonella-associated bacillary angiomatosis.
PMID:24933445 SUPPORT REVIEW SYNTHESIS Human Clinical
"erythromycin is the first-line antibiotic therapy for the treatment of angioproliferative lesions."
The Bartonella pathogenicity and treatment review identifies erythromycin as first-line therapy for Bartonella angioproliferative disease.
PMID:21285862 SUPPORT PRIMARY RESULT Human Clinical
"The patient was successfully treated with 2 weeks of azithromycin after which all symptoms resolved."
Documents a bacillary angiomatosis case resolving after azithromycin.
+ 1 more reference
IV Doxycycline With Gentamicin or Rifampin
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: 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. Gentamicin NCIT:C519 NCI Thesaurus (NCIT) Relation: this treatment uses this therapeutic agent This treatment uses Gentamicin (NCIT:C519). NCIT:C519 is a therapeutic agent from the NCI Thesaurus. Rifampin NCIT:C811 NCI Thesaurus (NCIT) Relation: this treatment uses this therapeutic agent This treatment uses Rifampin (NCIT:C811). NCIT:C811 is a therapeutic agent from the NCI Thesaurus.
Platform: Small molecule
Severely ill patients with HIV-associated Bartonella disease may require IV doxycycline combined with gentamicin or rifampin for prolonged therapy.
Mechanism Target:
Bartonella Ribosomal Translation — Doxycycline and gentamicin suppress Bartonella protein synthesis through the bacterial ribosome.
Show evidence (1 reference)
PMID:11362939 SUPPORT REVIEW SYNTHESIS Human Clinical
"Severely ill patients should receive IV doxycycline with either gentamicin or rifampin for at least four months."
Review guidance escalates severely ill HIV-infected patients to prolonged IV doxycycline plus gentamicin or rifampin.
Adjunctive Antiretroviral Therapy
Action: Antiretroviral TherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Antiretroviral Therapy (NCIT:C94631). NCIT:C94631 is a clinical intervention from the NCI Thesaurus. NCIT:C94631
Platform: Small molecule
In HIV-associated bacillary angiomatosis, antiretroviral therapy is an adjunct to antibiotics that restores host immune control.
Mechanism Target:
Bartonella Infection in Immunocompromised Host — Immune reconstitution reduces the immunosuppressed host state that permits disseminated Bartonella vasoproliferation.
Show evidence (1 reference)
PMID:27428207 SUPPORT PRIMARY RESULT Human Clinical
"Antibiotic treatment with doxycycline and antiretroviral therapy resulted in clinical improvement."
B. quintana bacillary angiomatosis with severe HIV immunosuppression improved after antibacterial therapy plus antiretroviral treatment.
🌍

Environmental Factors

2
Cat and flea exposure
Cat and cat-flea contact supply the zoonotic B. henselae exposure context linked to B. henselae bacillary angiomatosis-peliosis.
Show evidence (1 reference)
PMID:9407154 SUPPORT Human Clinical
"Patients with B. henselae infection were identified throughout the study period and were epidemiologically linked to cat and flea exposure (P< or =0.004)"
Establishes cat and flea exposure as the B. henselae-associated risk context in bacillary angiomatosis-peliosis.
Mechanism Target:
TRIGGERS Bartonella Infection in Immunocompromised Host — Cat or flea exposure introduces B. henselae, enabling infection in a susceptible immunocompromised host.
Show evidence (1 reference)
PMID:9407154 SUPPORT Human Clinical
"Patients with B. henselae infection were identified throughout the study period and were epidemiologically linked to cat and flea exposure (P< or =0.004)"
Molecular epidemiology of bacillary angiomatosis-peliosis links the B. henselae species subset to cat and flea exposure.
Homelessness-associated body louse exposure
Homelessness, low income, and body-louse exposure are the epidemiologic context for B. quintana bacillary angiomatosis-peliosis.
Show evidence (1 reference)
PMID:9895398 SUPPORT Human Clinical
"In an outbreak of urban trench fever among homeless people in Marseilles, B. quintana infections were associated with body lice in patients with nonspecific symptoms or no symptoms."
Establishes body lice as the B. quintana vector in the same homelessness-associated exposure setting.
Mechanism Target:
TRIGGERS Bartonella Infection in Immunocompromised Host — Body-louse exposure supplies B. quintana and can initiate infection in a susceptible host.
Show evidence (1 reference)
PMID:9407154 SUPPORT Human Clinical
"whereas those with B. quintana were clustered and were characterized by low income (P=0.003), homelessness (P = 0.004), and exposure to lice (P= 0.03)"
Molecular epidemiology of bacillary angiomatosis-peliosis links the B. quintana species subset to homelessness and louse exposure.
🔬

Diagnosis

2
Histopathology With Warthin-Starry Stain (Positive)
Biopsy of vascular lesions with hematoxylin-eosin morphology plus Warthin-Starry staining can distinguish bacillary angiomatosis from Kaposi sarcoma and other vascular mimics.
Show evidence (1 reference)
PMID:24718378 SUPPORT Human Clinical
"A Warthin-Starry stain highlighted clumps of bacilli, confirming the diagnosis of BA."
Human biopsy review documents Warthin-Starry-positive bacilli as the confirmatory diagnostic finding in bacillary angiomatosis lesions.
Bartonella PCR on Lesional Tissue (Positive)
PCR-based amplification from tissue can confirm Bartonella infection and speciate the organism when culture is slow or insensitive.
Show evidence (1 reference)
PMID:9407154 SUPPORT Human Clinical
"The infecting bartonella species were determined by molecular techniques."
Molecular techniques speciated Bartonella organisms from bacillary-angiomatosis-peliosis cases in the landmark case-control study.
📈

Progression

2
Bartonella-associated vasoproliferation
B. henselae or B. quintana infection establishes Bartonella endothelial virulence signaling in a host whose impaired immunity permits proliferative angiomatous lesions instead of contained infection.
Show evidence (1 reference)
PMID:9407154 SUPPORT Human Clinical
"Of the 49 patients with bacillary angiomatosis-peliosis, 26 (53 percent) were infected with B. henselae and 23 (47 percent) with B. quintana."
Molecular epidemiology in bacillary angiomatosis-peliosis tissue implicates both Bartonella species in human vasoproliferative disease.
Cutaneous and disseminated lesion formation
Angiomatous papules, nodules, and plaques may remain cutaneous or involve liver, spleen, bone, blood, endocardium, and nearly any organ in advanced infection.
Show evidence (1 reference)
PMID:11362939 SUPPORT REVIEW SYNTHESIS Human Clinical
"Patients may have osseus BA lesions (frequently affecting the long bones); hepatic and/or splenic lesions; bacteremia; or endocarditis."
The review summarizes the disseminated skeletal, hepatosplenic, bloodstream, and endocardial extension of bacillary angiomatosis in HIV-associated Bartonella infection.
🦠

Infectious Agent

2
Bartonella henselae
Cat-associated Gram-negative Bartonella species that causes bacillary angiomatosis-peliosis and is epidemiologically linked to cat and flea exposure.
Bartonella henselae NCBITaxon:38323 NCBI Taxonomy (NCBITaxon)
Show evidence (1 reference)
PMID:21285862 SUPPORT REVIEW SYNTHESIS Human Clinical
"Bacillary angiomatosis is an infectious disease caused by 2 gram-negative bacilli, Bartonella henselae and Bartonella quintana."
The case-report review directly identifies B. henselae as one of the two recognized bacillary angiomatosis etiologic agents.
Bartonella quintana
Human-louse-associated Gram-negative Bartonella species that causes bacillary angiomatosis-peliosis and is epidemiologically linked to low income, homelessness, and louse exposure.
Bartonella quintana NCBITaxon:803 NCBI Taxonomy (NCBITaxon)
Show evidence (1 reference)
PMID:21285862 SUPPORT REVIEW SYNTHESIS Human Clinical
"Bacillary angiomatosis is an infectious disease caused by 2 gram-negative bacilli, Bartonella henselae and Bartonella quintana."
The case-report review directly identifies B. quintana as one of the two recognized bacillary angiomatosis etiologic agents.
{ }

Source YAML

click to show 
name: Bacillary Angiomatosis
creation_date: "2026-09-26T07:38:50Z"
category: Infectious Disease
description: >-
  Bacillary angiomatosis is a Bartonella-driven vasoproliferative infection
  characterized by tumor-like capillary lesions of the skin, subcutaneous
  tissue, liver, spleen, bone, and other viscera, chiefly in immunocompromised
  hosts.
disease_term:
  preferred_term: bacillary angiomatosis
  term:
    id: MONDO:0000758
    label: bacillary angiomatosis
parents:
- bartonellosis
- angiomatosis
- skin disease caused by bacterial infection
synonyms:
- Bartonella angiomatosis
- bacillary epithelioid angiomatosis
- epithelioid angiomatosis
references:
- reference: PMID:9407154
  title: Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
- reference: PMID:21285862
  title: "Bacillary angiomatosis in an immunocompetent child: a case report and review of the literature."
- reference: PMID:11362939
  title: Bartonella-associated infections in HIV-infected patients.
- reference: PMID:24933445
  title: Pathogenicity and treatment of Bartonella infections.
- reference: PMID:32678094
  title: The Bartonella autotransporter BafA activates the host VEGF pathway to drive angiogenesis.
- reference: PMID:18627378
  title: The head of Bartonella adhesin A is crucial for host cell interaction of Bartonella henselae.
- reference: PMID:23163798
  title: Bartonella henselae trimeric autotransporter adhesin BadA expression interferes with effector translocation by the VirB/D4 type IV secretion system.
- reference: PMID:24718378
  title: "Bacillary angiomatosis masquerading as Kaposi's sarcoma in East Africa."
- reference: PMID:22316326
  title: "Cutaneous bacillary angiomatosis in renal transplant recipients: report of three new cases and literature review."
infectious_agent:
- name: Bartonella henselae
  description: >-
    Cat-associated Gram-negative Bartonella species that causes bacillary
    angiomatosis-peliosis and is epidemiologically linked to cat and flea
    exposure.
  infectious_agent_term:
    preferred_term: Bartonella henselae
    term:
      id: NCBITaxon:38323
      label: Bartonella henselae
  evidence:
  - reference: PMID:21285862
    reference_title: "Bacillary angiomatosis in an immunocompetent child: a case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Bacillary angiomatosis is an infectious disease caused by 2 gram-negative
      bacilli, Bartonella henselae and Bartonella quintana.
    explanation: >-
      The case-report review directly identifies B. henselae as one of the two
      recognized bacillary angiomatosis etiologic agents.
- name: Bartonella quintana
  description: >-
    Human-louse-associated Gram-negative Bartonella species that causes bacillary
    angiomatosis-peliosis and is epidemiologically linked to low income,
    homelessness, and louse exposure.
  infectious_agent_term:
    preferred_term: Bartonella quintana
    term:
      id: NCBITaxon:803
      label: Bartonella quintana
  evidence:
  - reference: PMID:21285862
    reference_title: "Bacillary angiomatosis in an immunocompetent child: a case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Bacillary angiomatosis is an infectious disease caused by 2 gram-negative
      bacilli, Bartonella henselae and Bartonella quintana.
    explanation: >-
      The case-report review directly identifies B. quintana as one of the two
      recognized bacillary angiomatosis etiologic agents.
progression:
- phase: Bartonella-associated vasoproliferation
  notes: >-
    B. henselae or B. quintana infection establishes Bartonella endothelial
    virulence signaling in a host whose impaired immunity permits proliferative
    angiomatous lesions instead of contained infection.
  evidence:
  - reference: PMID:9407154
    reference_title: Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Of the 49 patients with bacillary angiomatosis-peliosis, 26 (53 percent)
      were infected with B. henselae and 23 (47 percent) with B. quintana.
    explanation: >-
      Molecular epidemiology in bacillary angiomatosis-peliosis tissue
      implicates both Bartonella species in human vasoproliferative disease.
- phase: Cutaneous and disseminated lesion formation
  notes: >-
    Angiomatous papules, nodules, and plaques may remain cutaneous or involve
    liver, spleen, bone, blood, endocardium, and nearly any organ in advanced
    infection.
  evidence:
  - reference: PMID:11362939
    reference_title: Bartonella-associated infections in HIV-infected patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Patients may have osseus BA lesions (frequently affecting the long bones);
      hepatic and/or splenic lesions; bacteremia; or endocarditis.
    explanation: >-
      The review summarizes the disseminated skeletal, hepatosplenic,
      bloodstream, and endocardial extension of bacillary angiomatosis in
      HIV-associated Bartonella infection.
pathophysiology:
- name: Bartonella Infection in Immunocompromised Host
  description: >-
    B. henselae or B. quintana reaches tissue in a host whose immune suppression
    permits Bartonella infection to progress into bacillary angiomatosis rather
    than remaining a contained lymphadenitic infection.
  biological_scale: ORGANISM
  biological_processes:
  - preferred_term: biological process involved in interaction with host
    term:
      id: GO:0051701
      label: biological process involved in interaction with host
  evidence:
  - reference: PMID:24933445
    reference_title: Pathogenicity and treatment of Bartonella infections.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Clinical manifestations can range from benign and self-limited to severe
      and life-threatening disease.
    explanation: >-
      The Bartonella pathogenicity review supports a host-context-dependent
      clinical spectrum from benign to severe disease.
  downstream:
  - target: Bartonella Angiogenic VEGFR2 Signaling
    description: >-
      Infected tissue exposes endothelial cells to Bartonella angiogenic factors.
  - target: Bartonella Intracellular Persistence
    description: >-
      Bartonella infection includes host-cell-associated bacterial niches that
      motivate intracellularly active antibacterial therapy.
  - target: Bartonella Ribosomal Translation
    description: >-
      Bacillary angiomatosis depends on living Bartonella with active bacterial
      ribosomal protein synthesis.
  - target: Fever
    description: Systemic Bartonella infection can present with fever.
  - target: Lymphadenopathy
    description: Systemic Bartonella disease may include lymph-node enlargement.
  - target: Anemia
    description: Disseminated B. henselae disease can include anemia in advanced HIV.
  - target: BadA-Mediated Endothelial Adhesion and VEGF Secretion
    description: >-
      B. henselae BadA supports endothelial adhesion and proangiogenic VEGF
      secretion.
  - target: VirB/D4 Bep Endothelial Survival Signaling
    description: >-
      VirB/D4-secreted Bep effectors separately inhibit endothelial apoptosis
      and induce angiogenic reprogramming.
- name: Bartonella Angiogenic VEGFR2 Signaling
  description: >-
    Bartonella BafA acts as a pro-angiogenic autotransporter whose passenger
    domain activates VEGF receptor 2 signaling, stimulating endothelial
    proliferation and angiogenesis.
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: vascular endothelial growth factor receptor signaling pathway
    modifier: INCREASED
    term:
      id: GO:0048010
      label: vascular endothelial growth factor receptor signaling pathway
  - preferred_term: angiogenesis
    modifier: INCREASED
    term:
      id: GO:0001525
      label: angiogenesis
  evidence:
  - reference: PMID:32678094
    reference_title: The Bartonella autotransporter BafA activates the host VEGF pathway to drive angiogenesis.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      BafA interacts with vascular endothelial growth factor (VEGF) receptor-2
      and activates the downstream signaling pathway, suggesting that BafA
      functions as a VEGF analog.
    explanation: >-
      Identifies BafA as a Bartonella VEGFR2-activating ligand, the upstream
      signal driving endothelial angiogenesis in this node.
  downstream:
  - target: Lobular Capillary Proliferation
    causal_link_type: DIRECT
    description: >-
      VEGFR2-dependent angiogenic signaling drives capillary endothelial
      proliferation.
    evidence:
    - reference: PMID:32678094
      reference_title: The Bartonella autotransporter BafA activates the host VEGF pathway to drive angiogenesis.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        Here, we use functional transposon-mutant screening in Bartonella
        henselae to identify such factor as a pro-angiogenic autotransporter,
        called BafA.
      explanation: >-
        Functional screening links BafA to Bartonella-induced pro-angiogenic
        endothelial behavior.
- name: BadA-Mediated Endothelial Adhesion and VEGF Secretion
  description: >-
    Bartonella henselae BadA supports endothelial adhesion, extracellular-matrix
    binding, and HIF-1-dependent VEGF secretion that separately prime infected
    endothelium for angioproliferation.
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: cell adhesion
    modifier: INCREASED
    term:
      id: GO:0007155
      label: cell adhesion
  - preferred_term: angiogenesis
    modifier: INCREASED
    term:
      id: GO:0001525
      label: angiogenesis
  evidence:
  - reference: PMID:18627378
    reference_title: The head of Bartonella adhesin A is crucial for host cell interaction of Bartonella henselae.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      Expression of Bartonella adhesin A (BadA) is crucial for bacterial
      autoagglutination, adhesion to host cells, binding to extracellular matrix
      proteins and proangiogenic reprogramming via activation of hypoxia
      inducible factor (HIF)-1.
    explanation: >-
      B. henselae endothelial-cell experiments link BadA itself to host-cell
      adhesion and HIF-1-mediated angiogenic reprogramming.
  downstream:
  - target: Lobular Capillary Proliferation
    description: >-
      BadA-dependent adhesion and VEGF secretion promote the endothelial
      proliferation that forms bacillary angiomas.
- name: VirB/D4 Bep Endothelial Survival Signaling
  description: >-
    Bartonella henselae VirB/D4 translocates Bep effector proteins that drive
    invasome uptake, inhibit endothelial apoptosis, and activate an angiogenic
    phenotype independently of dense BadA expression.
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: negative regulation of apoptotic process
    modifier: INCREASED
    term:
      id: GO:0043066
      label: negative regulation of apoptotic process
  - preferred_term: angiogenesis
    modifier: INCREASED
    term:
      id: GO:0001525
      label: angiogenesis
  evidence:
  - reference: PMID:23163798
    reference_title: Bartonella henselae trimeric autotransporter adhesin BadA expression interferes with effector translocation by the VirB/D4 type IV secretion system.
    supports: SUPPORT
    evidence_source: IN_VITRO
    quote_role: BACKGROUND
    snippet: >-
      VirB/D4 translocates several Bartonella effector proteins (Beps) into the
      cytoplasm of infected ECs, resulting, e.g. in uptake of bacterial
      aggregates via the invasome structure, inhibition of apoptosis and
      activation of a proangiogenic phenotype.
    explanation: >-
      The paper's opening summary of prior endothelial-cell work supports
      modelling VirB/D4 Bep translocation as a pro-survival angiogenic branch;
      the node is separated from BadA because this study found that dense BadA
      interferes with VirB/D4-dependent effector translocation.
  downstream:
  - target: Lobular Capillary Proliferation
    description: >-
      VirB/D4-dependent endothelial survival and angiogenic reprogramming
      amplify capillary proliferation in bacillary angiomas.
- name: Lobular Capillary Proliferation
  description: >-
    Bartonella-driven endothelial signaling expands irregular dermal and
    visceral capillaries into nodular lobular proliferations with a mixed
    inflammatory stromal infiltrate and extracellular bacterial aggregates.
  biological_scale: TISSUE
  locations:
  - preferred_term: skin
    term:
      id: UBERON:0002097
      label: skin of body
  - preferred_term: liver
    term:
      id: UBERON:0002107
      label: liver
  - preferred_term: spleen
    term:
      id: UBERON:0002106
      label: spleen
  cell_types:
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: angiogenesis
    modifier: INCREASED
    term:
      id: GO:0001525
      label: angiogenesis
  - preferred_term: inflammatory response
    modifier: INCREASED
    term:
      id: GO:0006954
      label: inflammatory response
  evidence:
  - reference: PMID:24718378
    reference_title: "Bacillary angiomatosis masquerading as Kaposi's sarcoma in East Africa."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Histologic examination by dermatopathologists in the United States revealed
      nodular dermal proliferations of irregular capillaries lined by spindled to
      epithelioid endothelial cells.
    explanation: >-
      Histopathology from clinically suspected Kaposi sarcoma cases establishes
      the capillary endothelial proliferation that defines bacillary
      angiomatosis lesions.
  downstream:
  - target: Cutaneous Vascular Papules and Nodules
    description: >-
      Lobular vascular growth in the skin presents as angiomatous papules and
      subcutaneous nodules.
  - target: Papules
    description: Cutaneous capillary proliferation presents as papular lesions.
  - target: Subcutaneous Nodules
    description: >-
      Deeper lobular proliferations can present as subcutaneous nodules.
  - target: Hepatosplenic Involvement
    description: >-
      Lesion dissemination to liver and spleen produces hepatosplenic bacillary
      disease.
  - target: Splenic Lesions
    description: Disseminated angioproliferative Bartonella lesions can involve the spleen.
  - target: Peliosis Hepatis
    description: >-
      B. henselae-associated bacillary angiomatosis-peliosis can form blood-filled
      peliotic lesions in the liver.
  - target: Lytic Bone Lesions
    description: >-
      Disseminated bacillary angiomatosis can produce long-bone destructive
      lesions.
- name: Bartonella Intracellular Persistence
  description: >-
    Bartonella species can occupy host-cell niches, so treatment of
    angioproliferative Bartonella infection favors agents such as macrolides and
    doxycycline that penetrate eukaryotic cells.
  biological_scale: CELLULAR
  conforms_to: "intracellular_pathogen_persistence#Intracellular Niche and Beta-Lactam Exclusion"
  biological_processes:
  - preferred_term: biological process involved in interaction with host
    term:
      id: GO:0051701
      label: biological process involved in interaction with host
  evidence:
  - reference: PMID:21557057
    reference_title: Adhesins of Bartonella spp.
    supports: SUPPORT
    evidence_source: IN_VITRO
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      The ability to cause vasculoproliferative disorders and intraerythrocytic
      bacteraemia are unique features of the genus Bartonella.
    explanation: >-
      Bartonella can occupy host-cell-associated niches, supporting
      intracellular activity as a treatment-relevant mechanism anchor.
- name: Bartonella Ribosomal Translation
  description: >-
    B. henselae and B. quintana require bacterial 70S ribosomal translation;
    erythromycin and doxycycline act on bacterial protein synthesis during
    prolonged therapy for bacillary angiomatosis.
  biological_scale: MOLECULAR
  conforms_to: "bacterial_protein_synthesis_inhibition#Bacterial mRNA Translation by the Ribosome"
  biological_processes:
  - preferred_term: translation
    term:
      id: GO:0006412
      label: translation
  evidence:
  - reference: PMID:24933445
    reference_title: Pathogenicity and treatment of Bartonella infections.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      erythromycin is the first-line antibiotic therapy for the treatment of
      angioproliferative lesions.
    explanation: >-
      Macrolide treatment of Bartonella angioproliferative lesions supports the
      bacterial ribosome as a therapy anchor for bacillary angiomatosis.
environmental:
- name: Cat and flea exposure
  description: >-
    Cat and cat-flea contact supply the zoonotic B. henselae exposure context
    linked to B. henselae bacillary angiomatosis-peliosis.
  influences_mechanisms:
  - target: Bartonella Infection in Immunocompromised Host
    environmental_effect: TRIGGERS
    causal_link_type: DIRECT
    description: >-
      Cat or flea exposure introduces B. henselae, enabling infection in a
      susceptible immunocompromised host.
    evidence:
    - reference: PMID:9407154
      reference_title: Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        Patients with B. henselae infection were identified throughout the study
        period and were epidemiologically linked to cat and flea exposure
        (P< or =0.004)
      explanation: >-
        Molecular epidemiology of bacillary angiomatosis-peliosis links the
        B. henselae species subset to cat and flea exposure.
  evidence:
  - reference: PMID:9407154
    reference_title: Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Patients with B. henselae infection were identified throughout the study
      period and were epidemiologically linked to cat and flea exposure
      (P< or =0.004)
    explanation: >-
      Establishes cat and flea exposure as the B. henselae-associated risk
      context in bacillary angiomatosis-peliosis.
- name: Homelessness-associated body louse exposure
  description: >-
    Homelessness, low income, and body-louse exposure are the epidemiologic
    context for B. quintana bacillary angiomatosis-peliosis.
  influences_mechanisms:
  - target: Bartonella Infection in Immunocompromised Host
    environmental_effect: TRIGGERS
    causal_link_type: DIRECT
    description: >-
      Body-louse exposure supplies B. quintana and can initiate infection in a
      susceptible host.
    evidence:
    - reference: PMID:9407154
      reference_title: Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        whereas those with B. quintana were clustered and were characterized by
        low income (P=0.003), homelessness (P = 0.004), and exposure to lice (P=
        0.03)
      explanation: >-
        Molecular epidemiology of bacillary angiomatosis-peliosis links the
        B. quintana species subset to homelessness and louse exposure.
  evidence:
  - reference: PMID:9895398
    reference_title: Chronic Bartonella quintana bacteremia in homeless patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      In an outbreak of urban trench fever among homeless people in Marseilles,
      B. quintana infections were associated with body lice in patients with
      nonspecific symptoms or no symptoms.
    explanation: >-
      Establishes body lice as the B. quintana vector in the same
      homelessness-associated exposure setting.
phenotypes:
- name: Cutaneous Vascular Papules and Nodules
  category: Dermatologic
  description: >-
    Skin lesions are vascular, friable, trauma-sensitive angiomatous papules,
    scaling plaques, subcutaneous nodules, or deeper soft-tissue masses.
  phenotype_term:
    preferred_term: Vascular skin abnormality
    term:
      id: HP:0011276
      label: Vascular skin abnormality
  evidence:
  - reference: PMID:11362939
    reference_title: Bartonella-associated infections in HIV-infected patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Lesions may affect almost any organ, and appear as angiomatous papules,
      dry scaling lesions, subcutaneous nodules, cellulitic plaques or deep,
      highly vascularized, soft tissue masses.
    explanation: >-
      Review evidence for the core angiomatous papules, subcutaneous nodules,
      plaques, and soft-tissue masses that define cutaneous bacillary
      angiomatosis.
- name: Papules
  category: Dermatologic
  description: Papular vascular lesions are one cutaneous presentation.
  phenotype_term:
    preferred_term: Papule
    term:
      id: HP:0200034
      label: Papule
  evidence:
  - reference: PMID:11362939
    reference_title: Bartonella-associated infections in HIV-infected patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Lesions may affect almost any organ, and appear as angiomatous papules,
      dry scaling lesions, subcutaneous nodules, cellulitic plaques or deep,
      highly vascularized, soft tissue masses.
    explanation: The review specifically lists angiomatous papules as a lesion morphology.
- name: Subcutaneous Nodules
  category: Dermatologic
  description: Subcutaneous nodules are another cutaneous or soft-tissue presentation.
  phenotype_term:
    preferred_term: Skin nodule
    term:
      id: HP:0200036
      label: Skin nodule
  evidence:
  - reference: PMID:11362939
    reference_title: Bartonella-associated infections in HIV-infected patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Lesions may affect almost any organ, and appear as angiomatous papules,
      dry scaling lesions, subcutaneous nodules, cellulitic plaques or deep,
      highly vascularized, soft tissue masses.
    explanation: The review specifically lists subcutaneous nodules as a lesion morphology.
- name: Hepatosplenic Involvement
  category: Abdominal
  description: >-
    Bacillary angiomatosis-peliosis can involve the liver or spleen, especially
    in disseminated immunocompromised-host disease.
  review_notes: >-
    Intentionally left unbound: the supporting evidence documents hepatic and
    splenic lesions rather than organomegaly, and the reviewed HP cache has no
    specific hepatic bacillary lesion term.
  evidence:
  - reference: PMID:11362939
    reference_title: Bartonella-associated infections in HIV-infected patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Patients may have osseus BA lesions (frequently affecting the long bones);
      hepatic and/or splenic lesions; bacteremia; or endocarditis.
    explanation: The review supports hepatic and splenic bacillary angiomatosis lesions.
- name: Splenic Lesions
  category: Abdominal
  description: Disseminated bacillary angiomatosis can affect the spleen.
  review_notes: >-
    Intentionally left unbound: the source establishes splenic lesions rather
    than splenomegaly, and no specific HPO term for bacillary splenic lesions
    was found in the local HP cache.
  evidence:
  - reference: PMID:11362939
    reference_title: Bartonella-associated infections in HIV-infected patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Patients may have osseus BA lesions (frequently affecting the long bones);
      hepatic and/or splenic lesions; bacteremia; or endocarditis.
    explanation: The review supports splenic involvement in bacillary angiomatosis.
- name: Lytic Bone Lesions
  category: Musculoskeletal
  description: >-
    B. quintana-associated bacillary angiomatosis-peliosis can produce lytic
    bone lesions, especially in subcutaneous or disseminated disease.
  phenotype_term:
    preferred_term: Osteolysis
    term:
      id: HP:0002797
      label: Osteolysis
  evidence:
  - reference: PMID:9407154
    reference_title: Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Subcutaneous and lytic bone lesions were strongly associated with B.
      quintana, whereas peliosis hepatis was associated exclusively with B.
      henselae.
    explanation: >-
      Molecularly speciated case-control data link lytic bone lesions with
      B. quintana bacillary angiomatosis-peliosis.
- name: Peliosis Hepatis
  category: Abdominal
  description: >-
    B. henselae bacillary angiomatosis-peliosis can present with peliosis
    hepatis, a peliotic vascular lesion pattern in the liver.
  review_notes: >-
    Intentionally left unbound: the report's suggested HP:0410042 resolves to
    Abnormal liver morphology rather than Hepatic peliosis, and no specific
    hepatic peliosis HPO term was present in the local HP cache.
  evidence:
  - reference: PMID:9407154
    reference_title: Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Subcutaneous and lytic bone lesions were strongly associated with B.
      quintana, whereas peliosis hepatis was associated exclusively with B.
      henselae.
    explanation: >-
      Molecularly speciated bacillary angiomatosis-peliosis cases tie peliosis
      hepatis specifically to B. henselae.
- name: Fever
  category: Constitutional
  description: Fever can accompany cutaneous and systemic bacillary angiomatosis.
  phenotype_term:
    preferred_term: Fever
    term:
      id: HP:0001945
      label: Fever
  evidence:
  - reference: PMID:10718405
    reference_title: Bacillary angiomatosis affecting the oral cavity. Report of two cases and review.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Multiple cutaneous nodular lesions together with fever, chills, malaise,
      anorexia, vomiting and headache are the most important clinical
      manifestations.
    explanation: >-
      Review synthesis lists fever among the important manifestations of
      bacillary angiomatosis.
- name: Lymphadenopathy
  category: Immune
  description: Lymphadenopathy can accompany bacillary angiomatosis in systemic disease.
  phenotype_term:
    preferred_term: Lymphadenopathy
    term:
      id: HP:0002716
      label: Lymphadenopathy
  evidence:
  - reference: PMID:22316326
    reference_title: "Cutaneous bacillary angiomatosis in renal transplant recipients: report of three new cases and literature review."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      BA manifests on the skin with violaceous lesions mimicking Kaposi sarcoma,
      and is associated with fever, lymphadenopathy, and liver, spleen, or lung
      nodules.
    explanation: >-
      Organ-transplant-recipient case review identifies lymphadenopathy as an
      associated bacillary angiomatosis manifestation.
- name: Anemia
  category: Hematologic
  description: Disseminated B. henselae bacillary angiomatosis in AIDS can include severe anemia.
  phenotype_term:
    preferred_term: Anemia
    term:
      id: HP:0001903
      label: Anemia
  evidence:
  - reference: PMID:18098054
    reference_title: "Severe anemia, panserositis, and cryptogenic hepatitis in an HIV patient infected with Bartonella henselae."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: >-
      The authors report the case of an AIDS patient with bacillary
      angiomatosis, who had concurrent severe anemia, hepatitis, peritonitis,
      pleuritis, and pericarditis.
    explanation: >-
      B. henselae bacillary angiomatosis in AIDS presented with concurrent
      severe anemia in this clinical case.
diagnosis:
- name: Histopathology With Warthin-Starry Stain
  presence: Positive
  description: >-
    Biopsy of vascular lesions with hematoxylin-eosin morphology plus
    Warthin-Starry staining can distinguish bacillary angiomatosis from Kaposi
    sarcoma and other vascular mimics.
  evidence:
  - reference: PMID:24718378
    reference_title: "Bacillary angiomatosis masquerading as Kaposi's sarcoma in East Africa."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      A Warthin-Starry stain highlighted clumps of bacilli, confirming the
      diagnosis of BA.
    explanation: >-
      Human biopsy review documents Warthin-Starry-positive bacilli as the
      confirmatory diagnostic finding in bacillary angiomatosis lesions.
- name: Bartonella PCR on Lesional Tissue
  presence: Positive
  description: >-
    PCR-based amplification from tissue can confirm Bartonella infection and
    speciate the organism when culture is slow or insensitive.
  evidence:
  - reference: PMID:9407154
    reference_title: Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The infecting bartonella species were determined by molecular techniques.
    explanation: >-
      Molecular techniques speciated Bartonella organisms from
      bacillary-angiomatosis-peliosis cases in the landmark case-control study.
treatments:
- name: Prolonged Macrolide or Tetracycline Therapy
  description: >-
    Prolonged macrolide or tetracycline therapy treats angioproliferative
    Bartonella lesions, with erythromycin as a first-line agent, doxycycline as
    an alternative, and azithromycin or clarithromycin as reported macrolide
    options.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: erythromycin
      term:
        id: CHEBI:48923
        label: erythromycin
    - preferred_term: doxycycline
      term:
        id: CHEBI:50845
        label: doxycycline
    - preferred_term: azithromycin
      term:
        id: CHEBI:2955
        label: azithromycin
    - preferred_term: clarithromycin
      term:
        id: CHEBI:3732
        label: clarithromycin
  target_mechanisms:
  - target: Bartonella Intracellular Persistence
    description: >-
      Macrolides and tetracyclines reach the host-cell compartment where
      Bartonella can persist.
  - target: Bartonella Ribosomal Translation
    description: >-
      Erythromycin and doxycycline suppress Bartonella protein synthesis through
      the bacterial ribosome.
  evidence:
  - reference: PMID:11362939
    reference_title: Bartonella-associated infections in HIV-infected patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Treatment with erythromycin for at least three months is recommended, or
      with doxycycline if erythromycin is not well-tolerated.
    explanation: >-
      Review guidance supports prolonged erythromycin, or doxycycline as an
      alternative, for Bartonella-associated bacillary angiomatosis.
  - reference: PMID:24933445
    reference_title: Pathogenicity and treatment of Bartonella infections.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      erythromycin is the first-line antibiotic therapy for the treatment of
      angioproliferative lesions.
    explanation: >-
      The Bartonella pathogenicity and treatment review identifies erythromycin
      as first-line therapy for Bartonella angioproliferative disease.
  - reference: PMID:21285862
    reference_title: "Bacillary angiomatosis in an immunocompetent child: a case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: >-
      The patient was successfully treated with 2 weeks of azithromycin after
      which all symptoms resolved.
    explanation: >-
      Documents a bacillary angiomatosis case resolving after azithromycin.
  - reference: PMID:18098054
    reference_title: "Severe anemia, panserositis, and cryptogenic hepatitis in an HIV patient infected with Bartonella henselae."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: >-
      Treatment with clarithromycin resulted in resolution of the bacillary
      angiomatosis, fever, anemia, panserosites, and hepatitis.
    explanation: >-
      Documents disseminated B. henselae bacillary angiomatosis resolving with
      clarithromycin.
- name: IV Doxycycline With Gentamicin or Rifampin
  description: >-
    Severely ill patients with HIV-associated Bartonella disease may require IV
    doxycycline combined with gentamicin or rifampin for prolonged therapy.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: doxycycline
      term:
        id: CHEBI:50845
        label: doxycycline
    - preferred_term: Gentamicin
      term:
        id: NCIT:C519
        label: Gentamicin
    - preferred_term: Rifampin
      term:
        id: NCIT:C811
        label: Rifampin
  target_mechanisms:
  - target: Bartonella Ribosomal Translation
    description: >-
      Doxycycline and gentamicin suppress Bartonella protein synthesis through
      the bacterial ribosome.
  evidence:
  - reference: PMID:11362939
    reference_title: Bartonella-associated infections in HIV-infected patients.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Severely ill patients should receive IV doxycycline with either gentamicin
      or rifampin for at least four months.
    explanation: >-
      Review guidance escalates severely ill HIV-infected patients to prolonged
      IV doxycycline plus gentamicin or rifampin.
- name: Adjunctive Antiretroviral Therapy
  description: >-
    In HIV-associated bacillary angiomatosis, antiretroviral therapy is an
    adjunct to antibiotics that restores host immune control.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Antiretroviral Therapy
    term:
      id: NCIT:C94631
      label: Antiretroviral Therapy
  target_mechanisms:
  - target: Bartonella Infection in Immunocompromised Host
    description: >-
      Immune reconstitution reduces the immunosuppressed host state that permits
      disseminated Bartonella vasoproliferation.
  evidence:
  - reference: PMID:27428207
    reference_title: "Bacillary angiomatosis presenting with facial tumor and multiple abscesses: A case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    snippet: >-
      Antibiotic treatment with doxycycline and antiretroviral therapy resulted
      in clinical improvement.
    explanation: >-
      B. quintana bacillary angiomatosis with severe HIV immunosuppression
      improved after antibacterial therapy plus antiretroviral treatment.
📚

References & Deep Research

References

9
PMID:9407154
Molecular epidemiology of bartonella infections in patients with bacillary angiomatosis-peliosis.
No top-level findings curated for this source.
PMID:21285862
Bacillary angiomatosis in an immunocompetent child: a case report and review of the literature.
No top-level findings curated for this source.
PMID:11362939
Bartonella-associated infections in HIV-infected patients.
No top-level findings curated for this source.
PMID:24933445
Pathogenicity and treatment of Bartonella infections.
No top-level findings curated for this source.
PMID:32678094
The Bartonella autotransporter BafA activates the host VEGF pathway to drive angiogenesis.
No top-level findings curated for this source.
PMID:18627378
The head of Bartonella adhesin A is crucial for host cell interaction of Bartonella henselae.
No top-level findings curated for this source.
PMID:23163798
Bartonella henselae trimeric autotransporter adhesin BadA expression interferes with effector translocation by the VirB/D4 type IV secretion system.
No top-level findings curated for this source.
PMID:24718378
Bacillary angiomatosis masquerading as Kaposi's sarcoma in East Africa.
No top-level findings curated for this source.
PMID:22316326
Cutaneous bacillary angiomatosis in renal transplant recipients: report of three new cases and literature review.
No top-level findings curated for this source.

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (1)

Create: Bacillary Angiomatosis · 2026-09-26T08:05:26Z · View source

Created a de-novo Bacillary Angiomatosis entry from the OpenScientist deep-research report and manual verification. The report verified 35/35 references, and its term warnings were reviewed before replacing obsolete or generic suggestions with exact MONDO, NCBITaxon, GO, HP, CL, UBERON, NCIT, and CHEBI bindings. Curated B. henselae and B. quintana infectious-agent records, Bartonella angiogenic and survival signaling pathophysiology, vascular cutaneous/hepatosplenic/bone phenotypes, Warthin-Starry and tissue-PCR diagnostics, and prolonged erythromycin/doxycycline treatment. Verified 19 exact snippets, passed term/schema/reference validators plus reference-title and title-snippet gates, and had not opened a PR at record creation time.

OpenScientist ▸
Bacillary Angiomatosis — Comprehensive Disease Characterization Report
openscientist-autonomous 2026-09-26T00:51:30.616541

Bacillary Angiomatosis — Comprehensive Disease Characterization Report

Disease: Bacillary Angiomatosis (BA) MONDO: MONDO:0000758 · Category: Infectious disease (bacterial, vasoproliferative) Report basis: Aggregated disease-level evidence from peer-reviewed literature (reviews, landmark case-control study, mechanistic in vitro/in vivo studies). No individual-patient/EHR dataset was provided; findings are synthesized from PubMed primary literature. Evidence types are flagged as human clinical, in vitro, or model organism.

Summary (Answer to the Research Question)

Bacillary angiomatosis is an angioproliferative (vascular tumor–forming) infectious disease caused by the Gram-negative bacteria Bartonella henselae and Bartonella quintana, occurring almost exclusively in immunocompromised hosts—most classically advanced HIV/AIDS (CD4 typically <100 cells/µL) and also solid-organ transplant recipients—and only rarely in immunocompetent individuals. The bacteria hijack vascular endothelium: the secreted autotransporter BafA acts as a VEGF-receptor-2 agonist, the trimeric autotransporter adhesin BadA activates HIF-1 to drive proangiogenic reprogramming, and the VirB/D4 type IV secretion system injects Bep effectors that inhibit endothelial apoptosis—together producing lobular capillary proliferations in skin and viscera. It is diagnosed by biopsy (Warthin-Starry silver stain, PCR) and is highly curable with prolonged antibiotics (erythromycin or doxycycline), but disseminated untreated disease can be fatal. It is not a genetic disease; there are no causal human genes, and host immunosuppression plus species-specific exposures (cats/cat fleas for B. henselae; homelessness, alcoholism, body lice for B. quintana) are the key determinants.

1. Disease Information

Overview. BA is a rare, treatable, vasoproliferative bacterial infection characterized by tumor-like proliferations of small blood vessels in skin, subcutaneous tissue, and internal organs. First recognized in the HIV/AIDS epidemic of the 1980s, it is caused by chronic infection with Bartonella henselae or B. quintana (formerly genus Rochalimaea) (PMID 21285862, PMID 8335458).

Key identifiers. - MONDO: MONDO:0000758 - MeSH: Angiomatosis, Bacillary (D016917) - ICD-10: A44.8 (Other forms of bartonellosis); ICD-11: 1C30.Y (Other specified bartonellosis) - OMIM / Orphanet: Not a Mendelian disease → no OMIM gene entry; not a classic Orphanet rare-genetic entry (infectious etiology) - SNOMED CT: Bacillary angiomatosis (disorder)

Synonyms / alternative names: Bacillary angiomatosis-peliosis (when visceral peliosis coexists); epithelioid angiomatosis; bacillary epithelioid angiomatosis; (historically) Rochalimaea angiomatosis. Bacillary peliosis (hepatis/splenic) is the visceral counterpart.

Information source. Disease-level aggregated resources and primary literature (case series, one landmark molecular case-control study, mechanistic studies), not individual EHR data.

2. Etiology

Causal factors — infectious (not genetic). BA is caused by two Gram-negative bacilli: Bartonella henselae (NCBI:txid38323) and Bartonella quintana (NCBI:txid803). "Bacillary angiomatosis is an infectious disease caused by 2 gram-negative bacilli, Bartonella henselae and Bartonella quintana" (PMID 21285862). A permissive host state (immunosuppression) determines progression from infection to vasoproliferation: "The severity of Bartonella infection correlates with the patient's immune status" (PMID 24933445).

Risk factors (environmental / host). - Immunosuppression (dominant): advanced HIV/AIDS (e.g., CD4 47 cells/µL, PMID 27428207), solid-organ transplant recipients (PMID 22316326). Rare in immunocompetent hosts (PMID 21285862, PMID 16495874). - B. henselae exposures: cat contact and cat-flea (Ctenocephalides felis) exposure (P≤0.004) (PMID 9407154, PMID 9272384). - B. quintana exposures: low income (P=0.003), homelessness (P=0.004), body-louse exposure (P=0.03) (PMID 9407154); chronic alcoholism (PMID 7529895). - Genetic risk factors: None known. Not applicable — no susceptibility loci, causal variants, or modifier genes are established for the human host.

Protective factors. Immune competence / immune reconstitution (antiretroviral therapy in HIV) reduces risk and aids cure; ectoparasite control (cat flea control, delousing/hygiene) reduces exposure. No genetic protective variants are described.

Gene–environment interactions. Not applicable in the classical (human-genetic) sense; the operative interaction is host immune status × pathogen exposure (e.g., cat/flea or louse contact in an immunosuppressed host).

3. Phenotypes (with suggested HPO terms and qualitative frequencies)

BA phenotypes are clinical signs/physical manifestations (cutaneous vascular lesions), symptoms (fever, malaise), and laboratory abnormalities (anemia, thrombocytopenia). Onset is adult (tracks the immunosuppressed adult population); severity ranges mild-to-severe; course is progressive if untreated, resolving with therapy.

Phenotype Type Suggested HPO Frequency/notes
Cutaneous/subcutaneous vascular papules & nodules (red-violaceous, friable, bleed when traumatized) Physical sign HP:0200039 (Papule); HP:0000988 (Skin nodule); HP:0011276 (Vascular skin abnormality) Most common; hallmark manifestation (PMID 21285862, PMID 11362939)
Fever Symptom HP:0001945 Frequent, esp. systemic disease (PMID 10718405)
Lymphadenopathy Sign HP:0002716 Common (PMID 22316326)
Hepatomegaly / peliosis hepatis Sign/organ HP:0002240; HP:0410042 (Hepatic peliosis) B. henselae (PMID 9407154)
Splenomegaly / splenic peliosis Sign HP:0001744 Visceral disease (PMID 22316326)
Lytic bone lesions / bone pain Sign HP:0002754 (Osteomyelitis)/HP:0002653; HP:0002917 B. quintana, long bones (PMID 9407154, PMID 11362939)
Weight loss / anorexia / malaise Symptom HP:0001824; HP:0002039 Systemic disease (PMID 10718405)
Anemia Lab HP:0001903 Severe cases (PMID 18098054)
Thrombocytopenia Lab HP:0001873 B. quintana bacteremia (PMID 9895398)
GI involvement (hematemesis, mucosal nodules) Sign HP:0002248; HP:0025314 Rare (PMID 12894361)
Oral cavity lesions Sign HP:0000155 (Oral mucosa abnormality) Rare (PMID 28902296, PMID 10718405)
Panserositis (pleuritis/pericarditis/peritonitis) Sign HP:0032261/HP:0001698 Rare severe (PMID 18098054)

Quality-of-life impact: Painful/disfiguring skin lesions, bleeding, and systemic constitutional symptoms impair function; visceral disease can be life-threatening. No formal EQ-5D/SF-36 data exist for BA specifically; QoL burden is inferred from lesion morbidity and treatable nature.

4. Genetic / Molecular Information

Not applicable to the human host — BA is a bacterial infection, not an inherited disorder. There are no causal human genes, pathogenic germline/somatic variants, ClinVar entries, allele frequencies, modifier genes, epigenetic disease signatures, or chromosomal abnormalities.

The relevant "molecular" players are bacterial virulence genes (host-microbe interaction): - bafA — proangiogenic autotransporter; passenger domain functions as a VEGF analog (PMID 32678094); homologs in B. quintana, B. bacilliformis, B. elizabethae (PMID 35379004, PMID 36810719). - badA (Bartonella adhesin A) — trimeric autotransporter adhesin; head domain mediates host adhesion and HIF-1 activation (PMID 18627378, PMID 21557057). - virB/virD4 T4SS and Bep effector genes — translocation of effectors inhibiting apoptosis and driving proangiogenic phenotype (PMID 23163798). - B. quintana Vomps (variably expressed outer-membrane proteins) and Trw conjugation system for erythrocyte adherence (PMID 21557057).

5. Environmental Information

  • Infectious agents (causal): Bartonella henselae and Bartonella quintana (Alphaproteobacteria; family Bartonellaceae). B. henselae also causes cat scratch disease and peliosis hepatis; B. quintana also causes trench fever and endocarditis (PMID 18444576, PMID 24933445). A rare BA case from B. elizabethae has been reported (PMID 36810719).
  • Vectors/reservoirs: B. henselae — reservoir cats, vector cat flea Ctenocephalides felis; B. quintana — reservoir humans, vector body louse Pediculus humanus corporis (PMID 9272384).
  • Lifestyle factors: homelessness, poverty, chronic alcoholism (for B. quintana); cat ownership/exposure (for B. henselae) (PMID 9407154, PMID 7529895).
  • Toxins/radiation/occupational exposures: Not applicable.

6. Mechanism / Pathophysiology

Ordered causal chain (initiating infection → clinical lesion)

  1. Exposure/inoculation — a cat scratch/flea (B. henselae) or body louse (B. quintana) introduces Bartonella into skin/blood of a (usually immunocompromised) host. (human clinical/epidemiologic; PMID 9407154)
  2. Bacterial adhesion — the trimeric autotransporter adhesin BadA binds fibronectin/ECM and endothelial cells, leading to autoagglutination and firm attachment. (in vitro; PMID 18627378, PMID 21557057)
  3. Proangiogenic reprogramming (branch A) — BadA engagement activates HIF-1, which results in transcription of angiogenic genes and autocrine VEGF secretion by endothelial cells. (in vitro; PMID 18627378, PMID 23163798)
  4. VEGFR-2 mitogenic signaling (branch B) — the secreted autotransporter BafA binds VEGF receptor-2 and activates its downstream pathway (functioning as a VEGF analog), driving endothelial proliferation, tube formation, and microvessel sprouting. (in vitro + mouse; PMID 32678094)
  5. Anti-apoptotic survival (branch C) — the VirB/D4 T4SS translocates Bep effectors into endothelial cytoplasm, causing invasome-mediated uptake of bacterial aggregates and inhibiting apoptosis, so proliferating endothelium survives. (in vitro; PMID 23163798)
  6. Stromal amplification — infected pericytes increase VEGF with reduced coverage (PMID 23184416), and persistence in mesenchymal stromal cells further amplifies endothelial activation/angiogenesis (PMID 34031126). (in vitro)
  7. Lesion formation — combined proliferation + survival + inflammation produces a lobular capillary proliferation lined by plump epithelioid endothelial cells with neutrophilic infiltrate and stromal bacterial aggregates — the histologic bacillary angioma. (human clinical; PMID 24718378)
  8. Dissemination — because host immunity is impaired, lesions spread hematogenously to viscera (liver/spleen peliosis, bone, GI tract, CNS), which can lead to organ dysfunction, hemorrhage, and death if untreated. (human clinical; PMID 11362939, PMID 24933445)

Upstream vs downstream: Adhesion (BadA) and effector delivery (VirB/D4) are upstream; VEGF/VEGFR-2 signaling, HIF-1 activation, and apoptosis inhibition are the core intermediate nodes; endothelial proliferation → lesion formation → dissemination are downstream.

Molecular pathways: VEGF/VEGFR-2 signaling, HIF-1α transcriptional program, NF-κB–associated proangiogenic/anti-apoptotic signaling. KEGG/Reactome: VEGF signaling pathway; HIF-1 signaling pathway. Cellular processes: angiogenesis, endothelial proliferation, inhibition of apoptosis, inflammation. Immune involvement: disease is permitted by immunodeficiency; lesions show mixed neutrophilic/lymphocytic infiltrate; in immunocompetent hosts a granulomatous response contains infection (PMID 9784568). Suggested GO terms: angiogenesis (GO:0001525); sprouting angiogenesis (GO:0002040); VEGF receptor signaling pathway (GO:0048010); cellular response to hypoxia (GO:0071456); negative regulation of apoptotic process (GO:0043066); inflammatory response (GO:0006954). Suggested CL terms: endothelial cell (CL:0000115); blood vessel endothelial cell (CL:0000071); pericyte (CL:0000669); mesenchymal stem cell (CL:0000134); erythrocyte (CL:0000232, for B. quintana bacteremia). Omics: No human disease transcriptomic/proteomic/metabolomic BA signatures are established; mechanistic data are protein/pathway-level (VEGF, HIF-1, BafA/BadA/Bep).

7. Anatomical Structures Affected

  • Primary organ: skin (UBERON:0002097) and subcutaneous tissue (UBERON:0002072) — cutaneous/subcutaneous vascular nodules.
  • Secondary/visceral organs: liver (UBERON:0002107; peliosis hepatis), spleen (UBERON:0002106), bone/bone marrow (UBERON:0002481/UBERON:0002371; lytic lesions, long bones), lymph nodes (UBERON:0000029), GI tract (UBERON:0000160; esophagus/stomach/duodenum), oral mucosa (UBERON:0003343), lung (UBERON:0002048), heart/pericardium, CNS/brain (UBERON:0000955) (PMID 11362939, PMID 12894361, PMID 16495874).
  • Body systems: primarily cardiovascular/vascular (endothelium), with integumentary, hepatobiliary, skeletal, lymphatic/hematologic, digestive, and occasionally nervous involvement.
  • Tissue/cell level: vascular (connective/endothelial) tissue; target cells = vascular endothelial cells (CL:0000115), with pericytes (CL:0000669) and stromal cells; B. quintana/B. henselae also infect erythrocytes (CL:0000232) causing bacteremia.
  • Subcellular: bacteria localize extracellularly (stromal aggregates) and are taken up intracellularly via the invasome; effectors act in the endothelial cytoplasm/plasma membrane (GO:0005886 plasma membrane; GO:0005829 cytosol).
  • Lateralization: typically multifocal/bilateral and disseminated rather than lateralized; cutaneous lesions are widely distributed.

8. Temporal Development

  • Onset: adult-onset (parallels immunosuppressed adults); subacute/chronic/insidious course over weeks to months (e.g., 6-month growing lesions, PMID 23282705; 10-month nodule, PMID 9205511).
  • Progression: progressive if untreated, from localized papules to disseminated visceral disease; can be rapidly life-threatening with hemorrhage/organ involvement (PMID 12894361, PMID 18098054).
  • Course pattern: treatment-induced remission is the rule with adequate therapy; relapse occurs with inadequate/short courses (PMID 9272384, PMID 9205511).
  • Duration: not self-limited in immunocompromised hosts (requires antibiotics); may resolve with prolonged therapy and immune reconstitution.
  • Critical intervention window: early biopsy-based diagnosis and prompt antibiotics prevent dissemination and death; immune restoration (ART) is a key adjunct.

9. Inheritance and Population

  • Epidemiology: Rare; no precise population prevalence/incidence figures exist (opportunistic, under-reported). Incidence fell sharply in high-income settings after combination antiretroviral therapy reduced severe HIV immunosuppression; it remains under-recognized in sub-Saharan Africa despite high HIV prevalence (PMID 24718378). B. quintana seroprevalence is high in homeless populations (IgG ≥1:128 in 57% and ≥1:1024 in 11% of Tokyo homeless; PMID 16495631); B. quintana bacteremia in 14% of Marseille homeless (PMID 9895398).
  • Inheritance: Not applicable (infectious disease; no Mendelian inheritance, penetrance, expressivity, anticipation, mosaicism, founder effect, consanguinity, or carrier frequency).
  • Demographics: predominantly adults with immunosuppression; historically HIV-infected men; B. quintana clusters in homeless/alcoholic, low-income urban populations. No strong ethnic predisposition beyond socioeconomic exposure patterns. Sex ratio reflects the underlying at-risk populations rather than intrinsic disease bias.
  • Geographic distribution: worldwide; B. quintana ("urban trench fever") in homeless populations across the US, Europe, and Japan (PMID 11871479, PMID 16495631).

10. Diagnostics

  • Biopsy/histopathology (gold standard): lobular proliferation of capillaries lined by plump, epithelioid/spindled endothelial cells; mixed neutrophilic/leukocytoclastic infiltrate; extracellular amphophilic granular material (bacterial aggregates) (PMID 24718378, PMID 12152480). Warthin-Starry silver stain highlights clumps of bacilli — "A Warthin-Starry stain highlighted clumps of bacilli, confirming the diagnosis of BA" (PMID 24718378). Electron microscopy can visualize bacilli (PMID 11362939).
  • Molecular: PCR of lesional tissue (e.g., 16S rRNA, citrate synthase gltA, riboflavin synthase ribC, or a 298-bp Bartonella fragment) identifies and speciates the organism and can monitor treatment response (PMID 9205511, PMID 7529895, PMID 40090362).
  • Serology: indirect immunofluorescence antibody (IFA) for Bartonella-specific IgG/IgM; useful epidemiologically but poorly reliable for individual BA diagnosis (PMID 9272384, PMID 11362939).
  • Culture: possible but difficult/fastidious, slow-growing; low sensitivity (PMID 9272384).
  • Imaging: CT/MRI/ultrasound to define visceral (hepatosplenic peliosis, abscesses) and osseous lesions (PMID 27428207, PMID 22316326).
  • Laboratory: anemia, thrombocytopenia, elevated inflammatory markers may accompany systemic disease.
  • Genetic/omics testing: Not applicable (no human genetic test; no karyotype/CMA/mtDNA/repeat-expansion role).
  • Differential diagnosis: Kaposi sarcoma (key mimic), pyogenic granuloma, angiosarcoma, epithelioid hemangioma, verruga peruana (B. bacilliformis), cat-scratch disease — distinguished by Warthin-Starry-positive bacilli and vascular-proliferative histology (PMID 10718405, PMID 31780437). BA is antibiotic-curable, unlike KS.
  • Screening: No population screening; consider B. quintana testing in symptomatic homeless/alcoholic patients and BA in HIV patients with vascular skin lesions.

11. Outcome / Prognosis

  • Survival/mortality: With appropriate prolonged antibiotics, prognosis is excellent (lesions resolve). Untreated Bartonella infection can cause high mortality (PMID 24933445); disseminated/visceral disease (e.g., GI hemorrhage, panserositis) is potentially fatal (PMID 12894361, PMID 18098054).
  • Morbidity: disfiguring/painful, friable, bleeding skin lesions; visceral organ dysfunction; bone pain/lytic lesions. No standardized disability/QoL metrics for BA.
  • Disease course/complications: hemorrhage from friable lesions, airway/oronasal involvement (oronasal fistula, PMID 28902296), massive GI bleeding (PMID 12894361), anemia and multi-serosal involvement (PMID 18098054).
  • Recovery potential: high with treatment + immune reconstitution; relapse if therapy is too short.
  • Prognostic factors: degree/duration of immunosuppression (CD4 count), extent of dissemination, timeliness of diagnosis and adequacy/duration of antibiotics. PCR negativity of lesional material is a favorable treatment-response marker (PMID 9205511).

12. Treatment

  • First-line pharmacotherapy: Erythromycin (macrolide) is first-line for angioproliferative lesions — "erythromycin is the first-line antibiotic therapy for the treatment of angioproliferative lesions" (PMID 24933445). Doxycycline (tetracycline) is the principal alternative — "Doxycycline led to complete resolution" (PMID 28902296). Azithromycin and clarithromycin are also effective (PMID 21285862, PMID 18098054).
  • Duration: prolonged — erythromycin for at least three months is recommended (or doxycycline) to prevent relapse in immunocompromised patients (PMID 11362939).
  • Severe/systemic disease: add rifampicin; gentamicin + doxycycline for associated bacteremia/endocarditis (PMID 24933445).
  • Adjuncts: antiretroviral therapy for immune reconstitution in HIV patients (PMID 27428207); treat/eliminate ectoparasites.
  • Surgical/interventional: localized excision has been used but relapse/dissemination risk means antibiotics are essential (PMID 12152480, PMID 16495874).
  • Advanced/experimental therapeutics (gene/cell/RNA/targeted/immunotherapy): Not applicable — antibiotics are curative; no such therapies are used.
  • Adverse events: relate to the antibiotics used (GI intolerance with erythromycin/doxycycline; photosensitivity with doxycycline); a Jarisch-Herxheimer-like reaction can occur at treatment initiation.
  • Suggested NCIT/CHEBI terms: Erythromycin (NCIT:C578; CHEBI:42355); Doxycycline (NCIT:C513; CHEBI:50845); Azithromycin (NCIT:C609; CHEBI:2955); Clarithromycin (CHEBI:3732); Rifampicin (NCIT:C29408; CHEBI:28077); Gentamicin (NCIT:C61796; CHEBI:27412).

13. Prevention

  • Primary prevention: avoid the exposures — for B. henselae: cat-flea control, prompt cleaning of cat scratches, caution around cats (esp. for immunosuppressed) (PMID 22316326); for B. quintana: body-louse control/delousing, hygiene, and addressing homelessness (PMID 9895398, PMID 11871479).
  • Secondary prevention: early recognition and biopsy of vascular skin lesions in immunosuppressed/homeless patients; prompt antibiotics prevent dissemination.
  • Tertiary prevention: adequate-duration antibiotics + immune reconstitution (ART) to prevent relapse and complications.
  • Immunization: None available (no vaccine).
  • Public-health interventions: vector control (fleas/lice), sanitation and services for homeless populations, clinician awareness.
  • Genetic counseling/screening: Not applicable (non-genetic).
  • Prophylaxis: no established antibiotic prophylaxis; risk-factor reduction is the mainstay.

14. Other Species / Natural Disease

  • Taxonomy of pathogens: Bartonella henselae (NCBI:txid38323), Bartonella quintana (NCBI:txid803); related agents of pathological angiogenesis include B. bacilliformis (verruga peruana; NCBI:txid774) and B. elizabethae (NCBI:txid34113) (PMID 35379004, PMID 36810719).
  • Natural reservoir/animal disease: Cats (Felis catus, NCBI:txid9685) are the natural reservoir of B. henselae, harboring asymptomatic intraerythrocytic bacteremia — they are typically infected but not diseased (do not develop BA) (PMID 18444576, PMID 21637717). Fleas (Ctenocephalides felis) and, for B. quintana, human body lice are vectors/reservoirs (PMID 35545848, PMID 40090362).
  • Comparative biology: B. henselae induces angiogenesis in human endothelial cells but not feline endothelial cells, highlighting host-specific susceptibility (PMID 21637717). Bartonella is the only bacterial genus known to induce pathological angiogenesis in mammals (PMID 23184416).
  • Zoonotic potential: B. henselae is a zoonosis (cat-to-human via scratch/flea); B. quintana is human-adapted (louse-borne, human reservoir) (PMID 9272384). No orthologous human "disease gene" applies (bacterial etiology).
  • VBO breed associations: Not applicable.

15. Model Organisms

  • In vitro (primary models): human umbilical vein and skin microvascular endothelial cell lines (accelerated angiogenesis/wound healing on B. henselae infection; PMID 21637717); human brain vascular pericytes (increased VEGF; PMID 23184416); mesenchymal stromal cells (persistence amplifying angiogenesis; PMID 34031126); recombinant BafA passenger domain assays (EC proliferation, tube formation, sprouting; PMID 32678094).
  • Mouse model: immunocompetent C57BL/6 mice given intraperitoneal B. henselae develop granulomatous hepatitis peaking week 4, resolving by 12 weeks, with hepatic bacterial DNA persistence ≥3 months (PMID 9784568). (model organism)
  • In vivo angiogenesis: BafA drives angiogenesis in mice (PMID 32678094).
  • Genetic/transgenic disease models: Not applicable — BA is an infection; there are no knockout/knock-in "BA models." Bacterial mutants (e.g., badA⁻, bafA transposon mutants, virB/D4 strains) are used to dissect virulence (PMID 18627378, PMID 32678094, PMID 23163798).
  • Phenotype recapitulation & limitations: cellular models reproduce the angiogenic/anti-apoptotic signaling; the mouse model reproduces granulomatous containment in an immunocompetent host but not the disseminated vasoproliferative tumors of immunocompromised humans — underscoring that human immunosuppression is essential to full disease.

Supported and Refuted Hypotheses

Supported: 1. BA is caused by B. henselae and B. quintana and occurs mainly in immunosuppressed hosts. (PMID 21285862, 24933445) 2. Vasoproliferation is driven by bacterial proangiogenic factors: BafA (VEGFR-2 agonist), BadA (HIF-1 activation), and VirB/D4-delivered Beps (apoptosis inhibition). (PMID 32678094, 18627378, 23163798) 3. The two species have partly distinct tropism/exposures: B. quintana → subcutaneous/lytic bone lesions, homeless/louse-associated; B. henselae → peliosis hepatis, cat/flea-associated. (PMID 9407154) 4. Diagnosis rests on Warthin-Starry histopathology + PCR; treatment with prolonged macrolide/tetracycline is curative. (PMID 24718378, 11362939, 24933445)

Refuted / excluded: - BA is not a genetic/heritable disease; no human causal genes, variants, or inheritance pattern apply. - BA is not a neoplasm despite tumor-like appearance; it is a reversible, antibiotic-curable infection (distinguishing it from its mimic Kaposi sarcoma).

Limitations and Future Directions

  • Epidemiology lacks precise prevalence/incidence rates (rare, opportunistic, under-reported); QoL and formal outcome metrics are absent for BA specifically.
  • Mechanistic data derive largely from in vitro human EC/pericyte systems and B. henselae; fewer B. quintana mechanistic studies exist, and no immunocompromised animal model fully reproduces disseminated human BA.
  • Future work: an immunodeficient animal model of disseminated BA; comparative B. quintana vs B. henselae proangiogenic effector biology; molecular epidemiology in under-studied high-HIV-burden regions.

Evidence base: ~15 primary references (reviews, one landmark NEJM molecular case-control study [PMID 9407154], mechanistic in vitro/in vivo studies). Evidence types span human clinical (case series/epidemiology), in vitro (endothelial/pericyte/effector studies), and model organism (mouse). No individual-patient dataset was provided.

Artifacts

Reference Validation

Checked with linkml-reference-validator 0.3.0rc3.

Outcome Count
References checked 35
Resolved 35
Unresolved (possible confabulation) 0
Unverifiable 0
References weighed for topical relevance 35
On topic 33
Off topic 0

All extracted references resolved successfully.

Term Validation

Checked with linkml-term-validator 0.4.5, through the ols: adapter.

Outcome Count
Terms checked 56
Resolved 55
Unresolved (possible confabulation) 0
Obsolete 1
Unverifiable 0
Terms whose name was checked 11
Terms named correctly 2
Terms named as a different term 6
Terms whose name is worth a second look 3

Terms the report names something else

These identifiers resolve, so nothing about them looks wrong, and the ontology calls them something unrelated to what the report calls them. That usually means the identifier is not the one the sentence needs:

  • MONDO:0000758 (3 mentions) - the report calls it "if available"; MONDO calls it bacillary angiomatosis
  • HP:0001945 (1 mention) - the report calls it "Symptom"; HP calls it Fever
  • HP:0002716 (1 mention) - the report calls it "Sign"; HP calls it Lymphadenopathy
  • HP:0001744 (1 mention) - the report calls it "Sign"; HP calls it Splenomegaly
  • HP:0001903 (1 mention) - the report calls it "Lab"; HP calls it Anemia
  • HP:0001873 (1 mention) - the report calls it "Lab"; HP calls it Thrombocytopenia

Obsolete terms

These terms are real but deprecated. Citing one is not a fabrication; it does mean the report is naming something the ontology has retired:

  • NCIT:C29408 (RV-B7 (RECOMB VACCINIA/B7)) (1 mention)

Terms whose name is worth a second look

The report's name for these is recognisably related to the term's own name without being one of them. A loose paraphrase reads the same way as a citation of the wrong sibling term - and so does a related synonym, which the ontology records precisely because it names something adjacent rather than the same thing - so these are listed rather than judged:

  • HP:0000155 (1 mention) - the report calls it "Oral mucosa abnormality"; HP calls it Oral ulcer, and lists "Oral mucosal ulceration" among its other names
  • CL:0000115 (2 mentions) - the report calls it "vascular endothelial cells"; CL calls it endothelial cell
  • UBERON:0002097 (1 mention) - the report calls it "Primary organ: skin"; UBERON calls it skin of body**, and lists "skin organ" among its other names