混合性結合組織病(MCTD)の1症例

症例は50歳女性で,1991年頃より両肘関節の疼痛とレイノー現象を自覚するようになり前医にて慢性関節リウマチ(Rheumatoid arthritis, 以下RAと略)との診断を受け加療受けるも症状の改善なく,当科を受診した｡典型的な慢性関節リウマチの症状に乏しく,他の膠原病の存在を疑って検索したところ,抗RNP抗体陽性等の所見から,混合性結合組織病(mixed connective tissue disease, 以下MCTDと略)と診断した｡MCTDは初診時に慢性関節リウマチと誤診される例が多く,慢性関節リウマチに非典型的な症状を伴う場合は,MCTDが鑑別診断として重要と考えられた。

A 50-year-old woman, diagnosed as rheumatoid arthritis (RA) in 1991, had been treated with Lobenzarit disodium and non steroidal anti-inflammatory drugs (NSAIDs) before administration at our hospital. Despite the treatment with these drugs, her symptoms did not improve. She was admitted to our hospital for her progressive bilateral elbow joint pain and Raynaud's phenomenon. Although abnormal values of laboratory examinations such as an increased ESR (64mm/1hr), increased level of serum IgG (2854mg/㎗) and a positive RA test were shown, the clinical features of classical RA were not clear. There, she was diagnosed as mixed connective tissue disease (MCTD), because of high level of anti-RNP antibody in serum, Raynaud's phenomenom, multiple arthritis and constrictive ventilatory disturbance. Her symptoms and the results of labolatory examinations were clearly improved by glucocorticoid therapy.