透析患者の手指MP関節に発症したアミロイド関節炎の1例

Amyloid Arthropathy in a Metaoarpophalangeal (MP) Joint of a Hemodialysis Patient : Case Report

　抄録：長期の透析に伴う合併症の1つとして関節周囲のアミロイドの沈着による様々な症状が報告されている．今回われわれは手指の中手骨指節骨間（MP）関節に単独で発症したアミロイド関節炎の1例を経験した．症例は45歳の男性で右中指MP関節の腫脹と疼痛を主訴に来院した．理学所見上，MP関節の腫脹，熱感，圧痛を認めた．単純X線像ではMP関節は橈側に亜脱臼しており，関節裂隙の狭小化を認めた．MRIにて関節内にT1強調像で低信号，T2強調像で高信号の領域を認め，またガドリニウムで造影効果を認めたため，滑膜の増殖と考えた．症状が持続するため滑膜切除術を施行した．病理組織学的には，関節滑膜の増殖と炎症細胞の浸潤がみられ，Congo-red染色にて滑膜の一部にアミロイドの存在を確認することができた．透析患者の関節病変として本症は念頭に置くべき疾患である．

　The authors report a rare case of amyloid arthropathy occurring in the metacarpophalangeal (MP) joint of the right middle finger of a 45-year-old man. The patient had an 18-year history of chronic renal failure and was on hemodialysis. He presented complaining of pain in the MP joint of the right middle finger for several months, and physical examination revealed swelling and limitation of the range of motion of the joint. Radiographs of the hand showed radial subluxation and joint-space narrowing of the joint, and magnetic resonance imaging revealed synovial proliferation within the affected joint. After conservative treatment with anti-inflammatory agents, synovectomy was performed. Histologic examination of the synovial tissue obtained showed a severe inflammatory process characterized by synovial villus formation, infiltration by chronic inflammatory cells, and amyloid material confirmed by Congo-red staining.