グルタミン酸受容体抗体—抗NMDAR抗体を中心に

Anti-Glutamate Receptor Antibodies: Focusing on Anti-N-methyl-D-aspartate Receptor Encephalitis

自己免疫性脳炎関連自己抗体は，N-メチル-D-アスパラギン酸受容体（NMDAR）を標的とするものが最も多い。抗体陽性例は特徴的な臨床像を呈する。抗体は病態に密接に関与し，早期の免疫療法が有効である。診断には，NMDARの立体構造を認識する脳脊髄液中の抗体をcell-based assay法で検出することが必要である。発症機序，経過・予後，至適治療法など，今後検討すべき課題が多い。

Abstract

The most frequent antibody-mediated autoimmune encephalitis is anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, which presents unique clinical features. Antibodies directly affect the cognitive function of patients with anti-NMDAR encephalitis, and immunotherapy is required to ameliorate their symptoms. The antibody binding is conformational, and antibody detection requires cell surface expression of receptor antigens. There are many unresolved questions surrounding autoimmune encephalitis, such as determination of the triggers of immune reactions against central nervous system antigens, the involved brain lesions responsible for the patients' variable symptoms, the mechanism of neuronal dysfunction, the most effective treatment strategy, and how long the medication should be continued. These questions should be investigated in the future.