抗信号识别颗粒抗体肌病八例临床分析

Myopathy with antibodies to the signal recognition particle： report of 8 cases

目的总结抗信号识别颗粒抗体肌病患者的临床和骨骼肌病理改变特点。方法选择8例患者采取免疫印迹法测定血清肌炎抗体谱并进行肌肉活检，肌肉标本进行组织学、酶组织化学和免疫组织化学染色。免疫组织化学染色的第一抗体为鼠抗人CD8、CD20、CD68单克隆抗体，分别标记T细胞、B细胞和巨噬细胞，主要组织相容性复合体（MHC）-I单克隆抗体标记肌纤维膜，CD31单克隆抗体标记毛细血管内皮细胞。结果8例患者血清抗信号识别颗粒抗体均为强阳性，其中3例伴随R0-52抗体阳性。8例患者骨骼肌出现肌纤维坏死、再生以及巨噬细胞浸润，2例患者伴随肌纤维肥大和间质增生，2例伴随少数T细胞浸润。存在部分MHC．I阳性肌纤维，毛细血管密度正常。结论抗信号识别颗粒抗体肌病以缓慢发病的肢体无力为主要表现，可伴肺部病变。肌纤维坏死、再生为其主要病理改变。可以类似肌营养不良改变。

Objective We report the clinical and pathological features of 8 Chinese myopathy patients with antibodies to the signal recognition particle （SRP）. Methods Serum myositis antibody profiles were tested with immunoblotting. Muscle biopsies were performed for histological, enzyme histochemical and immunohistoehemical stainings. The first antibody in the immunohistoehemical staining was mouse anti-human monoclonal antibodies including CD8, CD20, CD68, MHC- I and CD31. Results Eight cases showed stark positive of anti SRP antibody, 3 of them with positive anti Ro-52 antibody. The muscle biopsies showed necrotic and regenerative muscle fibers associated with infiltration of macrophage, but scattered T lymphocytes in 2 patients. Two of them presented with fiber hypertrophy and proliferation of connective tissue. There were some fibers with positive MHC-I expression. Capillaries were almost normal. Conclusion The muscle weakness of myopathy with antibodies to SRP presents as a chronic progressive course and could associate with lung involvement. Fiber necrosis and regeneration are the main myopathological features, which can mimic muscular dystrophy in some cases.