应用免疫印迹法诊断肢带型肌营养不良2A型

目的 应用免疫印迹法(Western blot)诊断肢带型肌营养不良2A型(LGMD2A)患者并与LGMD2B型相鉴别.方法 收集我院诊治的4例LGMD2型患者的临床、病理及生化检验资料.取肌肉活体组织行组织化学和免疫组织化学染色,用Western blot分析dysferlin蛋白及calpain-3蛋白的表达.结果 LGMD2A与2B型患者的临床症状相似;免疫组织化学染色显示所有患者均出现不同程度的dysferlin缺失.但Western blot揭示:LGMD2A型患者calpain-3蛋白完全缺失,dysferlin蛋白部分缺失;而2B型患者则相反.结论 用Western blot检测calpain-3蛋白可在dysfedin蛋白表达缺失的LGMD患者中鉴别出2A型患者,该方法对临床辅助诊断LGMD2A有很好的价值.

Diagnosing limb-girdle muscular dystrophy type 2A by Western blot analysis

Objective To evaluate Western blot analysis in diagnosing limb-girdle muscular dystrophy type 2A (LGMD2A). Methods The clinical records including their pathological and biochemical results of 4 patients with LGMD type 2 were reviewed. Histochemical and immunohistochemical staining were performed on muscle biopsy specimens from the four patients. The expressions of dysferlin and calpain-3 in muscles were analyzed by Western biol. Results All 4 LGMD patients shared some common clinical features, such as dorsal muscular atrophy of lower limbs and remarkably elevated CK. The immunohistochemical results showed partial or complete deficiency of dysferlin staining in all 4 LGMD patients. However, Western blot revealed that the calpain-3 protein in the muscle of patient 1 was completely absent, who was later diagnosed with LGMD2A. The other 3 patients had complete dysferlin deficiency with reduced calpain-3 expression and they were confirmed to be LGMD2B. Conclusions Western blot analysis of calpain-3 and dysfcrlin can be used to differentiate LGMD2A which shows absence of calpain-3 from other LGMD types which show dysferlin deficiency. Western blot is an invaluable method in clinical diagnosis of LGMD2A.