肢带型肌营养不良和Miyoshi肌病dysferlin表达分析

目的探讨dysfedinopathy的临床、病理及分子病理特征。方法对45例临床病理诊断为肢带型肌营养不良（LGMD）和Miyoshi肌病（MM）患者的冰冻肌肉标本通过免疫组化染色（IHC）观察dysferlin、α-肌聚糖和肌营养不良蛋白（dystrophin）的表达,进一步用Western印迹分析法（WB）测定肌肉组织中dysferlin含量。结果在39例LGMD和6例MM患者肌肉标本中发现5例dysferlin完全缺失,另有3例dysferlin表达量在正常对照值的15％以下,这8例患者符合dysferlinopathy的诊断,其中LGMD3例,MM5例。平均发病年龄为18．8岁,2例LGMD患者为同胞兄妹,1例MM患者的父母为姑表兄妹,提示本病属常染色体隐性遗传方式。血清CK585—21280IU／L,平均6240IU／L,肌电图均显示肌源性损害,肌肉病理为典型肌营养不良改变,3例有炎细胞浸润。结论dysferlinopathy临床和普通肌肉病理缺乏特异性,部分患者肌组织中伴有炎细胞浸润,容易误诊为炎症性肌病。应用免疫组化和蛋白印迹方法对dysferlin的表达进行分析是诊断本病以及与炎症性肌病鉴别的必要手段。

Dysferlin expression in limb-girdle muscular dystrophy and Miyoshi myopathy: analysis of 45 cases

OBJECTIVE: To clarify the expression patterns of dysferlin in limb-girdle muscular dystrophy (LGMD) and Miyoshi myopathy (MM), and to investigate the frequency and clinicopathologic features of dysferlinopathy. METHODS: The expressing patterns of dysferlin were analyzed by immunohistochemistry, with a set of antibodies against dystrophin, alpha-sarcoglycan and dysferlin, in the biopsied muscle specimens from 45 patients with LGMD or MM diagnosed on the basis of clinical manifestations and muscle pathological features. The specimens with abnormal dysferlin expression shown by IHC were further analyzed with Western blotting for a quantitative evaluation. RESULTS: Eight patients were proved to be primary dysferlinopathy according to total dysferlin deficiency or a significant decrease of dysferlin (less than 15% that of normal value). The clinical manifestations of 5 of the 8 dysferlinopathy patients were consistent with those of typical MM, and the other 3 were diagnosed as with LGMD. All patients had an average onset at the age of 18.8 years. Two of them had family history, and one patient had consanguineous mating parents, meaning an autosomal recessive inheritance pattern. The serum CK levels were 6240 IU/L on average. EMG showed myogenic patterns in all patients. Muscular pathology showed typical changes of muscular dystrophy in all patients. Focal or scattered inflammatory cellular infiltrations were found in 3 cases. CONCLUSION: The clinical and pathological features of dysferlinopathy are nonspecific. Inflammatory cellular infiltrations are relatively common in biopsied muscles of dysferlinopathy patients, which may cause misdiagnosis of inflammatory myopathy. Identification of dysferlin expression by IHC and Western blotting are essential for the diagnosis of dysferlinopathy and differential diagnosis of inflammatory myopathy.