抗IL-6受容体抗体が奏効した消化管AAアミロイドーシスの1例

Amyloid A Amyloidosis Successfully Treated by Anti-Interleukin-6 Receptor Antibody（Tocilizumab）, Report of a Case

要旨　患者は62歳，女性．20歳時に関節リウマチ（RA）を発症しており，最近5年間は無治療で放置していた．慢性下痢，食欲不振，体重減少を主訴に来院した．消化管内視鏡検査で上行結腸から直腸に連続性，びまん性に浮腫状，発赤調，微細顆粒状を呈する粘膜と厚い白苔を有する多発性・大小不同の不整型潰瘍が認められた．また，十二指腸には微細顆粒状の粘膜と多発するびらんが認められた．生検にてアミロイド蛋白の沈着を認め，RAに合併したAAアミロイドーシスと診断した．抗IL-6受容体抗体（トシリズマブ）の投与により，臨床症状とともに，内視鏡・病理所見の改善が認められた．トシリズマブはRAに合併したAAアミロイドーシスの有効な治療法であると考えられた．

　A 62-year-old woman had suffered from rheumatoid arthritis for 42years without treatment these 5years. She presented with chronic diarrhea, appetite loss, and weight loss. Colonoscopy showed multiple irregular ulcers of various size accompanied by red edematous mucosa from the ascending colon to the rectum. Esophagogastroduodenoscopy showed multiple erosions with fine granular mucosa in the duodenum. She was pathologically diagnosed with AA amyloidosis by biopsy specimens which demonstrated amyloid protein deposition. After we initiated anti-interleukin-6 receptor antibody（tocilizumab）, her clinical symptoms was gradually improved as well as pathologic and endoscopic findings. Tocilizumab was considered an effective therapy for AA amyloidosis secondary to rheumatoid arthritis.