重症肌无力患儿胸腺细胞体外增殖和CD4、CD8、Fas测定

Detection of thymocyte proliferation in vitro and CD4, CD8, and Fas in children with myasthenia gravis

目的:探讨胸腺异常在儿童重症肌无力(MG)患者发病中的作用.方法:取临床确诊MG患儿手术切除的及24～38周流产胚胎胸腺组织(对照),分离胸腺细胞,MTT比色分析法观察胸腺细胞体外增殖情况;用流式细胞仪测定胸腺细胞表面膜CD4、CD8和Fas.结果:与对照相比,MG患儿体外培养胸腺细胞增殖能力增强(P＜0.01),胸腺细胞CD4 CD8+细胞增多(P＜0.01),CD4+CD8+细胞减少(P＜0.01),CD4-CD8-、CD4+CD8-细胞数量无变化;CD4+Fas+、CD8+Fas+胸腺细胞均减少(P＜0.01).结论:MG患儿胸腺细胞存在增殖和膜分子表达的异常.

Aim: To explore the role of thymocyte abnormality on pathogenesis of myasthenia gravis(MG).Methods: The thymocytes were isolated from fresh thymic tissue of children with MG and 24~38 week feta(the control).The proliferation of thymocytes was evaluated using MTT assay.The CD4,CD8, and Fas on the surface of thymocytes were detected using flow cytometry.Results: The proliferative capability of thymocytes in children with MG was more powerful than that of the control(P<0.01).The proportion of CD4+CD8+double positive thymocytes decreased and that of CD4-CD8+single positive thymocytes decreased significantly(P<0.01).The proportion of CD4+Fas+ and CD8+Fas+ thymocytes decreased significantly(P<0.01).Conclusion: There are thymocyte proliferation and abnormality of thymocyte membrane molecules in children with MG.