重症肌无力患者胸腺内B淋巴细胞亚群CD20的分布及临床意义

目的了解胸腺内Ｂ淋巴细胞与重症肌无力发生的关系。方法用免疫组化方法,分析胸腺瘤伴有和不伴有重症肌无力的患者肿瘤外胸腺内Ｂ淋巴细胞亚群ＣＤ２０的分布。结果发现伴有重症肌无力患者的胸腺内ＣＤ２０阳性细胞呈显著集合和中等集合,与不伴有重症肌无力者差异有极显著意义（χ２＝２６．０３２,Ｐ＜０．０１）;ＣＤ２０阳性细胞分布程度与胸腺瘤的分期呈负相关（γ＝０．７）,与重症肌无力临床分型无相关（γ＜０．４）。结论提示在重症肌无力的发病因素中,胸腺的病理改变比胸腺瘤更重要。由于抗乙酰胆碱受体抗体的异质性,Ｂ淋巴细胞集合程度并不能反映临床症状的轻重。

Distribution of B-lymphocyte subgroup CD20 and its clinical significance in patients with myasthenia gravis

OBJECTIVE: To assess the distribution and clinical significance of B-lymphocyte subgroup CD20 in patients with myasthenia gravis. METHOD: B-lymphocyte subset CD20 was studied in patients with thymomas associated with or without myasthenia gravis using immunohistochemistry technique. RESULT: The moderate and obvious aggregation of CD20 positive cells was found in patients with myasthenia gravis, there was a significant difference when compared with those patients without myasthenia gravis (chi(2) = 26.032, P < 0.01). There was negative correlation between the distribution of CD20 positive cells and the staging of thymomas (gamma = 0.07), and no correlation between the distribution and clinical type of myasthenia gravis (gamma < 0.4). CONCLUSION: The results of this study indicated that pathological changes of thymus are more important than those of thymomas itself in the pathogenesis of myasthenia gravis. The degree of B-lymphocyte subgroup aggregation can not truly reflect clinical status because of the heterogeneity of antibody against acetylcholine receptor.