ABSTRACT
Objective:To investigate whether FcγRⅡb rs775 single nucleotide polymorphism confers susceptibility to Hashimoto′s thyroiditis and its impact on expression of FcγRⅡb protein on B cell surface.Methods:A total of 187 Hashimoto′s thyroiditis patients(HT group) were enrolled, including 46 males(24.60%) and 141 females(75.40%), with a median age of 43(32, 53) years, and 187 healthy controls(conrol group), including 62 males(33.16%) and 125 females(66.84%), with a median age of 41(31, 51) years. The peripheral blood of two groups were sequenced, genotype and allele frequencies distribution of FcγRⅡb rs775 T>C were compared with clinical parameters as strata between the two groups. At the same time, the expression of inhibitory receptor FcγRⅡb on B cell surface was detected using flow cytometry.Results:Compared with control group, the mutant homozygous CC genotype was obviously enrichment in HT group( OR=3.321, 95% CI 1.175-9.386, P=0.018), and the proportion of CC genotype increased in male of HT group( P=0.076). However, there is no significant difference in genotype and allele frequencies between control group and HT group after stratification by sex. In addition, the percentage of FcγRⅡb on B cell surface decreased significantly in HT group( P=0.029). Conclusion:There was no significant correlation between FcγRⅡb polymorphism and the down-regulation of FcγRⅡb protein on B cell surface in Hashimoto′s thyroiditis patients, and FcγRⅡb can be a predisposed factor for Hashimoto′s thyroiditis.