Maeda Y, Arakawa K, Araki E, Kikuchi H, Ikezoe K, Taniwaki T, Kira J
Department of Neurology, Faculty of Medicine, Kyusyu University.
Rinsho Shinkeigaku. 1999 Jun;39(6):639-42.
We report a 60-year-old man with myelodysplastic syndrome (MDS) who developed polymyositis and cutaneous vasculitis. He noticed difficulty in climbing up stairs 4 months before admission. On admission, he showed brownish skin pigmentation in the distal positions of the four extremities. Neurological examination revealed muscle weakness of the neck flexor and proximal muscles of four extremities. Serum myogenic enzymes including creatine kinase increased, and electromyography showed denervation potentials and MUPs were myogenic, which was compatible with polymyositis. Muscle biopsy indicated perivascular mononuclear cell infiltration and muscle fiber necrosis with cytoplasmic bodies and rimmed vacuoles in the muscle fibers. Complete blood cell counts revealed macrocytic normochromic anemia and bone marrow puncture disclosed marked hyperplasia of megakaryocytes, erythroblasts and myeloblasts, suggesting a refractory anemia type of MDS. In addition, skin biopsy showed chronic cutaneous vasculitis. Serum protein electrophoresis and immunoelectrophoresis revealed the presence of IgM gamma type monoclonal gammopathy. With immunosuppressive therapy, serum creatine kinase level was decreased. Since immunological abnormalities and the presence of autoimmune diseases have been reported in patients with MDS, both polymyositis and chronic cutaneous vasculitis in the present patient may be caused by the similar autoimmune mechanisms related to MDS.
我们报告一名60岁患有骨髓增生异常综合征（MDS）的男性，他并发了多发性肌炎和皮肤血管炎。入院前4个月，他发现爬楼梯困难。入院时，他四肢远端出现褐色皮肤色素沉着。神经系统检查发现颈屈肌和四肢近端肌肉无力。包括肌酸激酶在内的血清肌源性酶升高，肌电图显示失神经电位且运动单位电位为肌源性，这与多发性肌炎相符。肌肉活检显示血管周围单核细胞浸润以及肌纤维坏死，肌纤维内有胞质体和镶边空泡。全血细胞计数显示大细胞正色素性贫血，骨髓穿刺显示巨核细胞、成红细胞和原始粒细胞明显增生，提示为难治性贫血型MDS。此外，皮肤活检显示慢性皮肤血管炎。血清蛋白电泳和免疫电泳显示存在IgMγ型单克隆丙种球蛋白病。经过免疫抑制治疗，血清肌酸激酶水平下降。由于已有报道MDS患者存在免疫异常和自身免疫性疾病，本患者的多发性肌炎和慢性皮肤血管炎可能由与MDS相关的类似自身免疫机制引起。
