TIRAP Ser180Leu polymorphism is associated with Behcet's disease

Area of Science:

• Immunology
• Genetics
• Rheumatology

Background:

• Behçet's disease (BD) etiology is unknown, with infection response suspected.
• Toll-like receptors (TLRs) are crucial for mucosal immunity.
• Single nucleotide polymorphisms (SNPs) in TLRs and associated genes were examined in BD.

Purpose of the Study:

• To analyze SNPs in TLRs and related molecules in Behçet's disease patients.
• To investigate the role of TLRs and associated genes in the pathogenesis of BD.
• To determine if specific genetic variants are associated with BD susceptibility.

Main Methods:

• Immunohistochemistry assessed TLR expression in buccal mucosa from BD patients, controls (lichen planus, pyogenic granuloma), and healthy individuals.
• Single nucleotide polymorphism (SNP) analysis of CD14, TLR2, TLR4, and TIRAP (TIR domain-containing adaptor protein) was performed using SSP-PCR.
• Patients were recruited from different geographical regions, including the UK and Middle East.

Main Results:

• TLR expression was elevated in BD lesions but also in disease controls, indicating a general inflammatory response.
• No significant association was found between BD and SNPs in CD14, TLR2, or TLR4.
• A specific variant, TIRAP 180Leu, showed a significant association with BD in UK patients, but not in Middle Eastern patients.

Conclusions:

• TLR expression levels in tissue did not differ significantly between BD patients and controls.
• No differences in SNPs within TLR genes were observed compared to healthy controls.
• The association of an increased function variant of TIRAP suggests a potential mechanism involving heightened cytokine production and tissue damage upon pathogen encounter at mucosal sites in BD.