重症肌无力胸腺淋巴细胞亚群表型的变化

The Changes of the Phenotypes of the Lymphocyte Subpopulation in Myasthenic Thymus

目的 研究重症肌无力 (myastheniagravis ,MG)患者胸腺的T、B淋巴细胞亚群表型 ,并分析与其外周血的相关性。方法 应用免疫荧光标记技术 ,经流式细胞仪分析 ,检测了 59例MG患者 ,包括 30例伴胸腺病变患者外周血的淋巴细胞亚群表型。另外 ,对 8例MG患者的胸腺和外周血经体外培养后进行检测。结果 ( 1)MG患者外周血辅助性T细胞 (Th ,CD4 +)异常增高 ,病程 6个月以内、伴胸腺增生者Th细胞均明显增多 ;( 2 )MG胸腺和外周血中经乙酰胆碱受体 (AChR)刺激后活化的Th细胞 (CD4 + CD2 5+)、CD5-B细胞 (CD5- CD19+)明显增多 ,且外周血CD5-B细胞与自身血清乙酰胆碱受体抗体 (AChRAb)滴度显著相关 (P <0 .0 1) ,胸腺摘除术 (Tx)后 ,MG外周血CD4 + CD2 5+、CD5- CD19+细胞均有所减少。结论 MG患者胸腺存在着异常的AChR特异应答性T、B淋巴细胞亚群表型 ,尤其以活化的Th细胞为著 ;CD5-B细胞的产生可能与MG密切相关。

Objective The phenotypes of the T、B lymphocyte subpopulation in myasthenic thymus were studied and the correlation of the peripheral blood(PB) and thymus were analyzed. Methods The immunofluorescence labeling technique was adopted to detect the phenotypes of the lymphocyte subpopulation in the peripheral blood (PB) of 59 myasthenia gravis (MG) patients including 30 cases with the thymus involved and the thymus and PB of 8 cases after cell culture in vitro via the flow cytometry were assayed. Results T helper cell (Th, CD4 +) in all MG patients were abnormally higher, even higher in those course lasted no more than six months and those with thymic hyperplasia.(2)The activated Th cells (CD4 +/CD25 +) were significantly increased in both myasthenic thymus and PB and CD5 - B cells (CD5 - /CD19 +) were increased in the myasthenic thymus after the stimulation of acetylcholine receptor (AChR) in vitro. In addition, the CD5 - B cells in PB of MG patients were correlated with their own serum acetylcholine receptor antibody (AChRAb) titer. After thymectomy (Tx), CD4 +/CD25 + and cells in the thymus and PB were decreased to some extent. Conclusion There are abnormal phenotypes of AChR specific responding T、B cell subpopulation in the myasthenic thymus, especially the activated Th cells. In addition,CD5 - B cells might be related to the pathogenesis of the MG.