特发性肌炎免疫机制研究及临床意义

Immunopathogenetic Mechanism of Idiopathic Inflammatory Myopathy and Clinical Significance

目的探讨多发性肌炎（PM）和皮肌炎（DM）患者骨胳肌组织损伤的免疫机制及临床意义。方法应用免疫荧光一步法和免疫组化SP法分析25例PM／DM肌组织中免疫球蛋白IgG、IgM、补体C3和浸润肌组织单核细胞的分布与定位。结果PM和DM肌组织中IgG、IgM、C3的阳性率分别为60％、33．3％、20％和70％、40％、50％，以IgG为主（P＜0．05），分布于肌组织血管壁、肌膜和肌浆中，补体C3在DM血管壁的分布有统计学意义（P＜0．05）；80％PM和7O％DM肌组织有单核细胞浸润，PM以T淋巴细胞为主，Ia＋活化TS细胞占多数，主要分布于肌内衣，DM以B淋巴细胞为主，多分布在肌柬衣血管周围。结论免疫反应在PM和DM发病机理中占重要地位，PM以T细胞介导的细胞毒作用为主，DM以体液免疫特别是补体介导的血管损害为主。

To study the immunopathogenetic mechanism and clinical significance on skeletal muscle lesions in polymyositis (PM) and dermatomyositis (DM). Methods The location and distribution of immunoglobulin IgG .IgM .complements C3 and mononucleate cells (MNC) infiltrating the skeletal muscles in 25 cases of PM and DM were detected by immunofluoresence and immunohistochemistry. Results IgG .IgM and C3 positive rates of PM were 60% .33. 3% and 20% and of DM were 70% .40% and 50% respectively and IgG was the highest (P＜0. 05). The immune complex was observed in the blood vessel walls,sarcolemma and intrafibers in muscle tissues. There existed statistically significant in the distribution of C3 in the blood vessel walls between DM and control groups (P＜0. 05 ). The positive rates of MNC infiltrating skeletal muscles of PM and DM were detected as 80% and 70% respectively. In PM, most of MNC were T lymphocytes which mainly distributed in the endmysium and a considerable proportion of T cells was T8 cells activated by la antigen. A high percentage of B cells was seen in DM and mainly surrounded the vessels in the perimysium. Conclusion The aberration of immunity might be Involved in pathologic process in PM and DM. T cell-mediated cytotoxicity plays a major role in PM, wheras a predominantly humoral immunity, specially the complement mediated vascular injury in DM.