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

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

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。

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(χ 2=26.032, P <0.01). There was negative correlation between the distribution of CD20 positive cells and the staging of thymomas (γ=0.07), and no correlation between the distribution and clinical type of myasthenia gravis (γ<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 heterogenity of antibody against acetylcholine receptor.