Fc?RIIa, IIIa and IIIb gene polymorphisms in Behçet's disease: Do they have any clinical implications?

Objective. Behçet's disease (BD) is a unique systemic vasculitis involving both arteries and veins of all sizes. Since Fc? receptors (Fc?R) are important in mediating various immune effector functions, Fc?R gene polymorphisms may affect the susceptibility to systemic inflammatory diseases such as BD. The aim of this study was to show the distribution of Fc?RIIa, IIIa ve IIIb receptor gene polymorphisms in BD, and to investigate possible genotype-phenotype relationships. Methods. In this cross-sectional study, Fc?RIIa (H/H131, H/R131, R/R131), IIIa (F/F158, F/V158, V/V158) and IIIb (NA1/NA1, NA1/NA2, NA2/NA2) receptor gene polymorphisms were investigated in 216 unrelated Turkish BD patients (M/F: 130/86) and in 241 healthy subjects, using an allele-specific polymerase chain reaction. Results. The Fc?RIIa R/R131 (p=0.019) and Fc?RIIIa F/F158 genotypes (p=0.001) were found to be significantly more frequent in BD compared with healthy controls, whereas the Fc?RIIIb genotypes were not (p=0.108). Allele analysis showed that the Fc?RIIIa F158 (p=0.001) and Fc?RIIIb NA2 (p=0.016) alleles were more frequent in BD than in healthy controls. In BD patients the Fc?RIIIa V/V158 genotype was significantly associated with the presence of arthritis (p=0.002) and with an earlier disease onset (p=0.008), while the Fc?RIIIb NA2/NA2 genotype was significantly associated with disease severity (p=0.02), vascular involvement (p=0.014), and pathergy positivity (p=0.02). Conclusion. We found that the genotype frequencies and allelic distributions of the Fc?RIIa, Fc?RIIIa and Fc?RIIIb gene polymorphisms were significantly different between BD patients and healthy controls. In addition, certain Fc?RIIIa and Fc?RIIIb gene polymorphisms appear to be associated with an early disease onset, disease severity, the presence of arthritis, and vascular involvement in BD. © Copyright Clinical and Experimental Rheumatology 2008.