Association of Fcgamma receptor polymorphisms with adult onset Still's disease in Korea
Fcgamma receptors (FcgammaR) have important functions in the regulation of immune response and clearance of immune complex. High levels of immunoglobulins have been observed in patients with the active stage of adult onset Still's disease (AOSD), and high-dose intravenous immunoglobulin treatment has decreased the disease activity of AOSD. We investigated polymorphisms of FcgammaR as genetic factors influencing susceptibility or disease course of AOSD in Korea. We genotyped the FcgammaRIIA H/R131, IIIA F/V176, and IIIB NA1/NA2 loci in 98 patients with AOSD and 151 healthy controls. Genotyping was performed using sequence-specific PCR. Patients with AOSD were subdivided into groups according to disease course: monocyclic systemic, polycyclic systemic, or chronic articular type. Allelic, genotypic, and haplotypic associations were analyzed by chi-square test. No significant skewing in any of the 3 FcgammaR polymorphisms was found between Korean AOSD patients and controls. FcgammaRIIA R/R131 and R/H131 genotype in patients with chronic articular-type disease was more frequent than in controls (p = 0.006 and p(corr) = 0.018). No differences of genotypic and allelic frequencies were found between other disease course types and controls. Haplotype IIA R131-IIIA F176-IIIB NA2 was more frequent in AOSD patients than in controls (p = 0.021). Although FcgammaR polymorphisms are not associated with development of AOSD in Koreans, the haplotype IIA R131-IIIA F176-IIIB NA2 may be associated with AOSD. Also, the FcgammaRIIA polymorphism may be associated with chronic articular-type AOSD. We need to identify whether these polymorphisms are associated with a response to anti-tumor necrosis factor agents in patients with AOSD.