桥本甲状腺炎患者FcγRⅡb单核苷酸多态性与FcγRⅡb蛋白表达的相关性研究

Correlation between single nucleotide polymorphism and protein expression of FcγRⅡb in Hashimoto′s thyroiditis

目的研究桥本甲状腺炎(Hashimoto′s thyroiditis)患者FcγRⅡb rs775位点单核苷酸多态性是否影响B细胞表面FcγRⅡb蛋白表达以及与桥本甲状腺炎易感性是否相关。方法选取187例桥本甲状腺炎患者(HT组),其中男性46例(24.60%),女性141例(75.40%),年龄43(32,53)岁;187名健康对照者为对照组,其中男性62名(33.16%),女性125名(66.84%),年龄41(31,51)岁。2组研究对象取外周血测序,以临床参数分层比较2组FcγRⅡb rs775 T>C基因型和等位基因频率分布,同时用流式细胞术检测B细胞表面抑制性受体FcγRⅡb表达情况。结果与对照组相比,HT组突变纯合CC基因型明显富集(OR=3.321,95%CI 1.175~9.386,P=0.018),在男性HT组患者中CC基因型比例升高(P=0.076)。按年龄分层后,各组间基因型与等位基因频率差异无统计学意义。此外,与对照组相比,HT组B细胞表面FcγRⅡb百分比显著下降(P=0.029)。结论桥本甲状腺炎患者中,FcγRⅡb多态性与B细胞表面FcγRⅡb蛋白表达下调无显著相关性,而FcγRⅡb rs775T>C可以作为桥本甲状腺炎发病的易感因素。

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.