外周血调节性T细胞在儿童与成人重症肌无力发病机制中的作用

目的 初步探讨外周血CD4+CD25+调节性T细胞在重症肌无力(MG)发病中的作用.方法 用流式细胞术分别检测儿童和成人MG外周血CD4+CD25+调节性T细胞的数最及其表达Foxp3和CTLA-4的情况.结果 儿童MG外周血CD4+CD25+调节性T细胞的数量明显高于正常儿童对照组,但其表达Foxp3水平反而大大低于对照组,成人MG比较差异无统计学意义.所有MG患者外周血CD4+CIY25+调节性T细胞表达的表面分子CTLA-4与正常对照比较,差异无统计学意义.结论 儿童MG患者外周血CD4+CD25+调节性T细胞存在着数量改变和功能缺失.提示儿童MG发病可能与外周血调节性T细胞免疫耐受功能受损有关.

The role of CD4+CD25+T cells in the mechanism of myasthenia gravis in children and adults

Objective To investigate the role of CD4+CD25+regulatory T cells in the mechanism of myasthenia gravis (MG) in children and adults. Methods Peripheral blood samples were collected from 13 MG patients,5 being aged >14 and 8 being aged ≤14,and 10 age-matched healthy persons. Peripheral blood mononuclear cells were isolated. Flow cytometry was used to examine the rate of CD4+CD25+regulatory T cells (Tregs). Fluorescence-activated cell sorter was used to detect the expression of Foxp3 and CTLA-4,2 important functional markers of CD4+CD25+Tregs. Results The percentage of CD4+CD25+Tregs of the MG children was significantly higher than that of the healthy children (P<0.05),and the percentage of CD4+CD25+Tregs of the MG adults was higher then that of the healthy adults,but not significantly (P=0.795). The expression level of Foxp3 of the MG children was significantly lower than that of the healthy children (P=0.011),and the expression level of Foxp3 of the MG adults was not significantly different from that of the healthy adult controls (P=0.084). The expression levels of CTLA-4 of beth the MG children and adults were lower than those of the healthy children and adults,but not significantly (P=0.556,P=0.767). Conclusion The CD4+CD25+Tregs in peripheral blood from MG pediatric patients are increased in number but unable functionally. The pathogenesis of MG in children may be correlated with the impairment of immunotolerance of the peripheral blood Tregs.