特发性血小板减少性紫癜患者B细胞活化因子的表达及其基因多态性

目的 检测特发性血小板减少性紫癜(ITP)患者血浆B细胞活化因子(BAFF)水平及其基因多态性,并探讨二者在ITP中的作用.方法 采用AS-PCR及琼脂糖凝胶电泳法检测133例ITP患者及117名健康对照者的BAFF启动子-871 C/T基因多态性,采用ELISA法测定其血浆BAFF抗原表达水平(BAFF∶Ag).结果 ITP组BAFF基因启动子C/C、C/T、T/T三种基因型分布分别为33.1%、42.1%和24.8%,对照组分别为55.6%、33.3%及11.1%.ITP组T等位基因频率为45.9%,对照组为27.4%,两组比较差异均有统计学意义(P值均＜0.05).初发ITP组、治疗组和对照组BAFF∶Ag分别为875.86、502.59和736.88 pg/ml,两组比较差异均有统计学意义(P值均＜0.05).ITP组和对照组T/T基因型BAFF∶Ag中较C/C、C/T基因型高,但差异无统计学意义(P＞0.05).结论 BAFF过表达可能是ITP发病的危险因素.BAFF启动子-871 C/T基因多态性在ITP发病中具有一定作用,但与BAFF基因表达无关.

Expression and gene polymorphisms of B cell activating factor in patients with idiopathic thrombocytopenic purpura

Objective To analyze the polymorphisms of B cell activating factor (BAFF) gene and the plasma levels of BAFF in patients with idiopathic thrombocytopenic purpura ( ITP), and to investigate their roles in the pathogenesis of ITP. Methods Alleles specific polymerase chain reaction (AS-PCR) and agarose gel electrophoresis were used to identify polymorphisms -871 C/T of BAFF promotor in 133 ITP patients and 117 healthy controls. The plasma levels of BAFF were assayed by ELISA. Results In ITP group,the frequency of C/C, C/T and T/T was 33.1%, 42.1% and 24.8%, respectively, the corresponding frequency in control group was 55.6%, 33.3% and 11.1%, respectively. The allele frequency of T in ITP and control groups was 45.9% and 27.4%, respectively. There was a significant difference in the BAFF -871C/T genotypic frequency between the ITP and control groups ( P ＜ 0. 05 ). BAFF antigen in untreated ITP,treated patients and controls was 875.86 pg/ml, 502.59 pg/ml and 736.88 pg/ml, respectively, being also asignificant difference among the three groups ( P ＜ 0.05 ). BAFF antigen in homozygous T/T was higher than that in homozygous C/C and heterozygous C/T, but the difference was not statistically significant (P ＞0.05 ). Conclusions Over expression of BAFF may be a risk factor for ITP patients. There is a correlation of the BAFF promotor polymorphism -871C/T with ITP, but the polymorphism does not affect the expression of BAFF.