Shimada K, Koh C S, Tsukada N, Shoji S, Yanagisawa N
Rinsho Shinkeigaku. 1989 Apr;29(4):432-5.
A case of myasthenia gravis accompanied with polymyositis and malignant thymoma, detected immune complexes in the sera and around the muscle fibers, was described. A 37-year-old woman was admitted to Shinshu University Hospital in September, 1987 because of dyspnea, dysphagia and muscle weakness. She first noticed her right blepharoptosis 3 weeks before admission. Weakness of all four limbs and myalgia of lower extremities were noticed one week later. These symptoms got worse and nocturnal dyspnea, dysphagia and easy fatigability at mastication appeared. On admission, she looked ill and neurological examination revealed left blepharoptosis, bilateral facial weakness, weakness of all four limbs, more prominent in proximal muscles and tenderness of lower extremities. Edrophonium test was positive, improving her muscle weakness. Laboratory examination revealed the elevated serum levels of CK, the increased titre of circulating immune complexes and high titres of acetylcholine receptor antibodies and anti-skeletal muscle antibodies. Electromyographic study showed myogenic pattern and Harvey-Masland test revealed waning at low frequency stimulation. Muscle biopsy showed marked perivascular infiltration of lymphocytes, accompanied by phagocytosis and interstitial fibrosis. IgG deposits were shown around the muscle fibers exclusively around the infiltrates of mononuclear cells. Granular deposits of C3 were also shown specifically around the muscle fibers exclusively around the infiltrates of mononuclear cells. Thymectomy was performed on September 21, 1987. Invasion of thymoma, predominantly lymphocytic type, to right lung and pericardium was observed histologically. After thymectomy, she got better. Immunological data and immunohistochemical examination of the present case suggest that in the case of myasthenia gravis accompanied with polymyositis and malignant thymoma, immune complexes may play a primary role on the pathogenesis of myositis.
报告了1例重症肌无力合并多发性肌炎和恶性胸腺瘤患者，在其血清和肌纤维周围检测到免疫复合物。一名37岁女性于1987年9月因呼吸困难、吞咽困难和肌无力入住信州大学医院。入院前3周她首次发现右眼上睑下垂。1周后出现四肢无力和下肢肌痛。这些症状逐渐加重，出现夜间呼吸困难、吞咽困难和咀嚼时易疲劳。入院时，她看起来病情较重，神经系统检查发现左眼上睑下垂、双侧面部肌无力、四肢无力，近端肌肉更明显，下肢压痛。依酚氯铵试验呈阳性，肌无力有所改善。实验室检查显示血清肌酸激酶水平升高、循环免疫复合物滴度增加以及乙酰胆碱受体抗体和抗骨骼肌抗体滴度升高。肌电图检查显示肌源性模式，Harvey-Masland试验显示低频刺激时递减。肌肉活检显示淋巴细胞明显血管周围浸润，伴有吞噬作用和间质纤维化。IgG沉积仅在单核细胞浸润周围的肌纤维周围显示。C3颗粒沉积也仅在单核细胞浸润周围的肌纤维周围特异性显示。1987年9月21日进行了胸腺切除术。组织学观察发现胸腺瘤（主要为淋巴细胞型）侵犯右肺和心包。胸腺切除术后，她病情好转。本病例的免疫学数据和免疫组织化学检查表明，在重症肌无力合并多发性肌炎和恶性胸腺瘤的病例中，免疫复合物可能在肌炎发病机制中起主要作用。
