臨床検査56巻1号

2012年01月発行

今月の主題 認知症と臨床検査 総論

認知症の病態

著者： 瓦林毅¹ 東海林幹夫¹

所属機関： ¹弘前大学大学院医学研究科脳神経内科学講座

ページ範囲：P.22 - P.30

多くの認知症疾患では蛋白の脳内異常蓄積が認められ，その異常蓄積が病態と相関しているとしてプロテイノパチーと呼ばれている．アルツハイマー病(AD)では初めにアミロイドβ蛋白(Aβ)の凝集蓄積が起こり，タウの蓄積など下流の変化を引き起こして神経細胞死をきたし，認知症を発症するというアミロイドカスケード仮説が信じられてきた．ADの根本治療もAβ蓄積を標的に開発が行われてきた．しかしAβ標的療法が臨床治験で有効性を示せず，この説に疑問が突きつけられている．一方，Aβやタウなどの異常蓄積蛋白がプリオンのように正常蛋白を凝集させながらニューロンからニューロンへと脳内を伝播していくことが示されている．

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