CD4^+ T细胞及其转录激活因子STAT4/6在免疫性血小板减少性紫癜中的表达及意义

The roles of CD4+T cell and its activating transcription factor STAT4/6 in immune thrombocytopenic purpura

目的探究免疫性血小板减少性紫癜(ITP)患者CD4^+T淋巴细胞亚群比例及其信号转录激活因子STAT4/6表达情况。探讨其在ITP发病机制中的作用。方法选取新诊断为ITP患者30例及正常健康人30例,抽取外周血,用流式细胞术检测CD4^+、CD3^+、CD8^+T细胞及CD4^+CD25^+Treg细胞,RT-PCR检测CD4^+T细胞转录激活因子STAT4/6表达,并进行统计分析。结果与正常健康组比较,ITP组患者外周血CD3^+、CD4^+、CD4^+CD25^+、CD4^+/CD8^+比值下降,差异有统计学意义(P<0.01);而CD8^+比例上升,差异有统计学意义(P<0.01)。ITP组STAT4/6的mRNA相对表达量均明显高于对照组(P<0.05)。结论 CD4^+T细胞亚群及细胞中STAT4/6表达变化可能促使机体Th1/Th2细胞因子的失衡,导致B淋巴细胞转化及分泌抗血小板抗体增加,CD8^+T血小板破坏增多。STAT4/6的表达异常可能在ITP发病机制中起重要作用。

Objective To investigate the subgroup proportions of CD4 ~T lymphocyte and the expression of the signal transducer and activator of transcription STAT4/6 in immune thromboeytopenic purpura （ITP） patients; And to ex- plore their roles in ITP. Methods The peripheral blood samples were collected from 30 ITP patients and 30 normal per- sons. The proportions of CD3 ＋ , CD4 ＋ , CD8 ＋ , and CD4 ＋ CD25 ＋ were analyzed by flow cytometry. The mRNA levels of the STAT4/6 in CD4 ＋ T cells were assessed by Real - Time PCR. Results The results showed that the proportions of CD3 ＋ , CD4 ＋ , CD4 ＋ CD25 ＋ , and CD4 ＋/CD8 ＋ were significantly reduced in ITP patients, compared to the normal con- trols （P 〈 0. 01 ）. The expression of STAT4/6 mRNA in ITP group was significantly higher than that of control group （P 〈 0. 05）. Conclusion The expression changes of STAT4/6 in CD4 ＋ T lymphocyte could lead to the unbalance of Thl/Th2 eytokines, then increases the transformation of B lymphocyte and the secretion of antiplatelet antibody. The abnormal ex- pression of STAT4/6 may play an important role in the pathogenesis of ITP.