胃と腸49巻3号

2014年03月発行

今月の主題 消化管アミロイドーシスを見直す 主題研究

関節リウマチに伴うAAアミロイドーシス

著者： 奥田恭章¹

所属機関： ¹道後温泉病院リウマチセンター

ページ範囲：P.335 - P.343

要旨　RAに伴うAAアミロイドーシスは，急性期炎症蛋白SAAを前駆蛋白として発症する．疾患感受性として，持続炎症，ageing，SAA1.3遺伝子多型が重要である．症状は蛋白尿・腎機能障害，消化器症状は難治性下痢や麻痺性イレウスが感染症併発時，手術時，関節外症状出現時などに生じる．進行を阻止する治療は，SAAの産生をできるだけ抑えることが最も合理的であり，抗サイトカイン療法が有用である．TNF阻害薬はSAAを低下させるが，産生抑制が不十分な例も少なからず存在する．一方，IL-6阻害薬は，作用機序から血中濃度を維持できればほぼ全例がSAA値の正常化が可能であり，今後の治療の主役になるであろう．

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