Behcet's Disease

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Classifications

Harrison's Chapter

⚙

Pathophysiology

3

HLA-B51-Associated Immune Dysregulation

Strong association with HLA-B51. Aberrant peptide presentation and cross-reactivity with microbial antigens may trigger autoinflammatory responses. ERAP1 variants affect peptide processing for HLA-B51.

Antigen Presentation link

Show evidence (1 reference)

PMID:38778397 PARTIAL

"genetic factors (such as HLA-B51), dysregulated immune responses of both the innate and adaptive immune systems, infections (such as streptococcus), and environmental factors (such as GDP) are all involved in its development."

This review confirms that HLA-B51 is a key genetic factor in Behcet's disease pathogenesis, supporting the role of aberrant antigen presentation in disease development.

Neutrophil Hyperactivation

Neutrophils show enhanced chemotaxis, phagocytosis, and oxidative burst. Pathergy response (exaggerated skin reaction to minor trauma) reflects neutrophil hyperreactivity. NETs may contribute to vascular damage.

Neutrophil link

Neutrophil Activation link

Show evidence (2 references)

PMID:38778397 PARTIAL

"Innate immunity, including hyperactivity of neutrophils and γδT cells and elevated NK1/NK2 ratios, has been shown to play an essential role in this disease."

This review highlights neutrophil hyperactivity as a key feature of innate immune dysregulation in Behcet's uveitis, supporting the role of neutrophil activation in pathogenesis.

PMID:37435539 SUPPORT

"Skin histopathology demonstrates the overactivation of innate immunity, such as neutrophilic dermatitis/panniculitis, in patients with BD."

Histopathological evidence confirms neutrophil overactivation in Behcet's disease skin lesions, demonstrating the pathologic role of neutrophils in tissue inflammation.

Th1/Th17 Cytokine Imbalance

Elevated IL-17, IFN-gamma, and TNF-alpha drive tissue inflammation. IL-23/IL-17 axis is particularly important and represents a therapeutic target.

T Helper Cell link

Inflammatory Response link

Show evidence (1 reference)

PMID:38778397 SUPPORT

"Adaptive immune system disturbance, including homeostatic perturbations, Th1, Th17 overaction, and Treg cell dysfunction, is thought to be involved in BU pathogenesis."

This review describes the imbalance between pro-inflammatory Th1/Th17 responses and regulatory T cell dysfunction as central to Behcet's uveitis pathogenesis, supporting the role of cytokine imbalance in disease progression.

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Phenotypes

4

Eye 1

Uveitis FREQUENT Uveitis (HP:0000554)

Panuveitis, may cause blindness

Show evidence (1 reference)

PMID:38778397 SUPPORT

"Behcet's uveitis (BU) is a common manifestation of BD, occurring in over two-thirds of the patients. BU is characterized by bilateral, chronic, recurrent, non-granulomatous uveitis in association with complications such as retinal ischemia and atrophy, optic atrophy, macular ischemia, macular..."

This review confirms that uveitis occurs in over two-thirds of Behcet's disease patients and describes its bilateral, recurrent nature and sight-threatening complications including potential blindness.

Genitourinary 1

Genital Ulcers VERY_FREQUENT Abnormality of the genitourinary system (HP:0000119)

Often scarring

Head and Neck 1

Oral Ulcers VERY_FREQUENT Oral ulcer (HP:0000155)

Recurrent, painful aphthous ulcers

Show evidence (1 reference)

PMID:37435539 SUPPORT

"Major clinical manifestations of BD are oral aphthae, genital aphthous ulcers, skin lesions, arthritis, and uveitis."

Oral aphthae are listed as a major clinical manifestation of Behcet's disease, confirming their central role in diagnosis.

Immune 1

Skin Lesions FREQUENT Skin rash (HP:0000988)

Erythema nodosum, pseudofolliculitis

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Genetic Associations

3

HLA-B51 (Strong Risk Factor)

ERAP1 (Risk Factor)

IL10 (Risk Factor)

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Treatments

5

Colchicine

For mucocutaneous manifestations.

Corticosteroids

For acute flares and severe manifestations.

Azathioprine

For maintenance and uveitis.

TNF Inhibitors

For refractory disease, especially uveitis.

Apremilast

For oral ulcers.

🔬

Biochemical Markers

2

ESR (Elevated)

Context: During active disease

CRP (Elevated)

Context: Inflammation marker

{ }

Source YAML

click to show

name: Behcet's Disease
creation_date: '2025-12-19T01:12:52Z'
updated_date: '2026-02-17T21:53:14Z'
category: Autoimmune
parents:
- Autoimmune Disease
- Vasculitis
disease_term:
  preferred_term: Behcet Disease
  term:
    id: MONDO:0007191
    label: Behcet disease
description: >-
  A systemic inflammatory disorder characterized by recurrent oral and genital
  ulcers, uveitis, and skin lesions. Involves both arterial and venous vessels
  of all sizes. Highly prevalent along the ancient Silk Road. Classified as a
  variable vessel vasculitis with autoinflammatory features.
pathophysiology:
- name: HLA-B51-Associated Immune Dysregulation
  description: >-
    Strong association with HLA-B51. Aberrant peptide presentation and
    cross-reactivity with microbial antigens may trigger autoinflammatory
    responses. ERAP1 variants affect peptide processing for HLA-B51.
  biological_processes:
  - preferred_term: Antigen Presentation
    term:
      id: GO:0019882
      label: antigen processing and presentation
  evidence:
  - reference: PMID:38778397
    reference_title: "Decoding Behcet's Uveitis: an In-depth review of pathogenesis and therapeutic advances."
    supports: PARTIAL
    snippet: >-
      genetic factors (such as HLA-B51), dysregulated immune responses of both
      the innate and adaptive immune systems, infections (such as streptococcus),
      and environmental factors (such as GDP) are all involved in its development.
    explanation: >-
      This review confirms that HLA-B51 is a key genetic factor in Behcet's
      disease pathogenesis, supporting the role of aberrant antigen presentation
      in disease development.
- name: Neutrophil Hyperactivation
  description: >-
    Neutrophils show enhanced chemotaxis, phagocytosis, and oxidative burst.
    Pathergy response (exaggerated skin reaction to minor trauma) reflects
    neutrophil hyperreactivity. NETs may contribute to vascular damage.
  cell_types:
  - preferred_term: Neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  biological_processes:
  - preferred_term: Neutrophil Activation
    term:
      id: GO:0042119
      label: neutrophil activation
  evidence:
  - reference: PMID:38778397
    reference_title: "Decoding Behcet's Uveitis: an In-depth review of pathogenesis and therapeutic advances."
    supports: PARTIAL
    snippet: >-
      Innate immunity, including hyperactivity of neutrophils and γδT cells and
      elevated NK1/NK2 ratios, has been shown to play an essential role in this
      disease.
    explanation: >-
      This review highlights neutrophil hyperactivity as a key feature of
      innate immune dysregulation in Behcet's uveitis, supporting the role of
      neutrophil activation in pathogenesis.
  - reference: PMID:37435539
    reference_title: "Innate immune responses in Behçet disease and relapsing polychondritis."
    supports: SUPPORT
    snippet: >-
      Skin histopathology demonstrates the overactivation of innate immunity,
      such as neutrophilic dermatitis/panniculitis, in patients with BD.
    explanation: >-
      Histopathological evidence confirms neutrophil overactivation in Behcet's
      disease skin lesions, demonstrating the pathologic role of neutrophils in
      tissue inflammation.
- name: Th1/Th17 Cytokine Imbalance
  description: >-
    Elevated IL-17, IFN-gamma, and TNF-alpha drive tissue inflammation.
    IL-23/IL-17 axis is particularly important and represents a therapeutic
    target.
  cell_types:
  - preferred_term: T Helper Cell
    term:
      id: CL:0000492
      label: CD4-positive helper T cell
  biological_processes:
  - preferred_term: Inflammatory Response
    term:
      id: GO:0006954
      label: inflammatory response
  evidence:
  - reference: PMID:38778397
    reference_title: "Decoding Behcet's Uveitis: an In-depth review of pathogenesis and therapeutic advances."
    supports: SUPPORT
    snippet: >-
      Adaptive immune system disturbance, including homeostatic perturbations,
      Th1, Th17 overaction, and Treg cell dysfunction, is thought to be involved
      in BU pathogenesis.
    explanation: >-
      This review describes the imbalance between pro-inflammatory Th1/Th17
      responses and regulatory T cell dysfunction as central to Behcet's uveitis
      pathogenesis, supporting the role of cytokine imbalance in disease
      progression.
phenotypes:
- name: Oral Ulcers
  category: Oral
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Oral Ulcer
    term:
      id: HP:0000155
      label: Oral ulcer
  notes: Recurrent, painful aphthous ulcers
  evidence:
  - reference: PMID:37435539
    reference_title: "Innate immune responses in Behçet disease and relapsing polychondritis."
    supports: SUPPORT
    snippet: >-
      Major clinical manifestations of BD are oral aphthae, genital aphthous
      ulcers, skin lesions, arthritis, and uveitis.
    explanation: >-
      Oral aphthae are listed as a major clinical manifestation of Behcet's
      disease, confirming their central role in diagnosis.
- name: Genital Ulcers
  category: Genitourinary
  frequency: VERY_FREQUENT
  phenotype_term:
    preferred_term: Abnormality of the Genitourinary System
    term:
      id: HP:0000119
      label: Abnormality of the genitourinary system
  notes: Often scarring
- name: Uveitis
  category: Ophthalmological
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Uveitis
    term:
      id: HP:0000554
      label: Uveitis
  notes: Panuveitis, may cause blindness
  evidence:
  - reference: PMID:38778397
    reference_title: "Decoding Behcet's Uveitis: an In-depth review of pathogenesis and therapeutic advances."
    supports: SUPPORT
    snippet: >-
      Behcet's uveitis (BU) is a common manifestation of BD, occurring in over
      two-thirds of the patients. BU is characterized by bilateral, chronic,
      recurrent, non-granulomatous uveitis in association with complications
      such as retinal ischemia and atrophy, optic atrophy, macular ischemia,
      macular edema, and further neovascular complications (vitreous hemorrhage,
      neovascular glaucoma).
    explanation: >-
      This review confirms that uveitis occurs in over two-thirds of Behcet's
      disease patients and describes its bilateral, recurrent nature and
      sight-threatening complications including potential blindness.
- name: Skin Lesions
  category: Dermatological
  frequency: FREQUENT
  phenotype_term:
    preferred_term: Skin Rash
    term:
      id: HP:0000988
      label: Skin rash
  notes: Erythema nodosum, pseudofolliculitis
biochemical:
- name: ESR
  presence: Elevated
  context: During active disease
- name: CRP
  presence: Elevated
  context: Inflammation marker
genetic:
- name: HLA-B51
  association: Strong Risk Factor
  notes: Present in 60-70% of patients from endemic regions
- name: ERAP1
  association: Risk Factor
- name: IL10
  association: Risk Factor
treatments:
- name: Colchicine
  description: For mucocutaneous manifestations.
- name: Corticosteroids
  description: For acute flares and severe manifestations.
- name: Azathioprine
  description: For maintenance and uveitis.
- name: TNF Inhibitors
  description: For refractory disease, especially uveitis.
- name: Apremilast
  description: For oral ulcers.
classifications:
  harrisons_chapter:
  - classification_value: musculoskeletal system disorder
  - classification_value: connective tissue disease
  - classification_value: autoimmune disease
references:
- reference: DOI:10.1038/s41598-025-87130-4
  title: Integrated analysis of genetic, proteinic, and metabolomic alterations
    in Behcet’s disease
  findings: []
- reference: DOI:10.1056/nejmra2305712
  title: Behçet’s Syndrome
  findings: []
- reference: DOI:10.1186/s12974-024-03123-6
  title: 'Decoding Behcet’s Uveitis: an In-depth review of pathogenesis and therapeutic
    advances'
  findings: []
- reference: DOI:10.3389/fimmu.2023.1206959
  title: Advances in pathogenesis and treatment of ocular involvement in
    Behcet’s disease
  findings: []
- reference: DOI:10.3389/fmed.2023.1055753
  title: Innate immune responses in Behçet disease and relapsing polychondritis
  findings: []
- reference: DOI:10.3390/medicina60040562
  title: 'Behçet’s Disease, Pathogenesis, Clinical Features, and Treatment Approaches:
    A Comprehensive Review'
  findings: []

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References & Deep Research