中文摘要：

目的检测共刺激分子B7-H1在重症肌无力（MG）患者胸腺组织中的表达,探讨与MG发病的关系。方法采用逆转录PCR（RT-PCR）技术检测30例MG患者B7-H1mRNA在胸腺组织中的表达水平,并分析与不同临床分型、病理类型之间的关系。同时设10例正常胸腺组织为对照组。结果MG组B7-H1mRNA表达水平为（0.46±0.21）,对照组为（0.14±0.14）,MG组较对照组显著增高（P〈0.01）。而MG组不同临床分型组间和不同病理类型组间其表达水平均无显著性差异（P〉0.05）。结论B7-H1mRNA在MG患者胸腺组织中的表达异常,可能影响到共刺激信号的传递,干扰到胸腺细胞的增殖与活化,参与MG的发病。

英文摘要：

Objective To measure the expression of costimulatory molecule B7-H1 in thymic tissue in patients of myasthenia gravis（MG）and explore the relations of it with the pathogenesis of MG.Methods Reverse transcription polymerase chain reaction（RT-PCR）technology was adopted to detect the expression of B7-H1 mRNA in thymic tissue in 30 cases of MG.It was to analyze the relations of it with different clinical type divisions and pathological types.Additionally,10 cases of normal thymic tissue were set up in control group.Results B7-H1 mRNA expression was（0.46±0.21）in MG group and was（0.14±0.14）in control group.The outcome in MG group was increased significantly compared with that in control group（P〈0.01）.There was no significant difference in the expression among different clinical type divisions and pathological types in MG group（P〉0.05）.Conclusion B7-H1 mRNA is expressed abnormally in thymic tissue of MG patient,which probably impacts the transmission of costimulatory signal,interferes in the proliferation and activation of thymic cells and participates in the pathogenesis of myasthenia gravis.