A transmembrane polymorphism in FcgammaRIIb (FCGR2B) is associated with the production of anti-cyclic citrullinated peptide autoantibodies in Taiwanese RA.

The aim of the current study was to determine whether the FcgammaRIIb 187-Ile/Thr polymorphism is a predisposition factor for subtypes of RA defined by disease severity and production of autoantibodies against cyclic citrullinated peptides (anti-CCPs) in Taiwanese RA patients. Genotype distributions and allele frequencies of FcgammaRIIb 187-Ile/Thr were compared between 562 normal healthy controls and 640 RA patients as stratified by clinical parameters and autoantibodies. Significant enrichment of 187-Ile allele was observed in RA patients positive for anti-CCP antibodies as compared with the anti-CCP negative RA patients (P=0.001, OR 1.652 (95% CI 1.210-2.257)) or as compared with the normal controls (P=0.005, OR 1.348 (95% CI 1.092-1.664)). In addition, 187-Ile allele was found to be enriched in RA patients positive for rheumatoid factor (RF) compared to the RF negative RA patients (P=0.024, OR 1.562 (95% CI 1.059-2.303)). Furthermore, the homozygotes were enriched in destructive male RA patients (P=0.035; OR 2.038 (95% CI 1.046-3.973)) and the 187-Ile allele was associated with early-onset of RA in Taiwanese patients (P=0.045, OR 1.548 (95% CI 1.007-2.379)). Thus, FcgammaRIIb SNP 187-Ile/Thr may influence the RA phenotypes in Taiwanese RA.