胸腺瘤组织内免疫状态的变化及分析

Abnormal changes of T lymphocyte subsets in thymoma

目的 分析胸腺瘤组织内免疫状态的变化及造成异常的原因。方法 应用流式细胞技术对正常胸腺和胸腺瘤组织中的T淋巴细胞亚群进行分析 ;应用免疫组织化学检测二者的主要组织相容性复合体 (MHC) Ⅰ、 Ⅱ类抗原的表达情况。患者按有无重症肌无力 (MG)分为两组MG(+ )、MG(-)。结果 两组中CD+ 4CD- 8亚群均较正常对照组明显增多 ,而CD+ 3CD+ 4亚群明显减少 ,P <0 .0 1。另外 ,MG(+ )组CD+4CD+8亚群较正常对照明显增加 ,P <0 .0 1;CD+3CD+8亚群明显减少 ,P <0 .0 1。MG(+ )较MG(-)组 ,CD+ 4CD+ 8亚群增加 ,而CD+ 3CD+ 8亚群明显减少 ,P <0 .0 1。正常胸腺组织中MHC 1、MHC Ⅱ均为强阳性表达。胸腺瘤无论是否合并MG ,组织中MHC Ⅰ表达强阳性 ,与对照组无差异 ;MHC Ⅱ未见阳性表达。结论 胸腺瘤组织中T淋巴细胞亚群及MHC Ⅱ的表达存在异常 ,T淋巴细胞亚群的异常可能与胸腺瘤内部在发育过程中阴性选择异常有关。

Objective To analyze the reason of the abnormal change of T lymphocyte subset and the correlation between thymoma and myasthenia gravis.Methods T lymphocytes subsets were detected by flow cytometry (FCM);the expression of major histocompatibility complex (MHC) molecules(MHC-Ⅰ,MHC-Ⅱ) by immunohistochemistry.According to that the patients with myasthenia gravis or the patients without myasthenia gravis were divided into two groups(MG+,MG-).Results The percentage of T lymphocyte subset was different in thymoma,as compared with that in normal thymus tissue (CD + 4 CD + 8 subsets increased,CD + 3 CD + 4 subsets reduced,P<0.01),and difference was also found between the two groups (CD + 4 and CD + 8 subsets increased in MG+ group,CD + 3 CD + 8 subsets reduced in MG+ group,(P<0.01).The expression of MHC-Ⅰ was found both in normal thymus tissue and thymoma,there was no difference between the two kinds of tissues.No expression of MHC-Ⅱ was observed in thymoma.Conclusion The T lymphocyte subset and the expression of MHC-Ⅱ are abnormal in thymoma tissues,and the abnormality may be related to negative choice of thymoma development.