巨細胞性動脈炎

Giant Cell Arteritis

巨細胞性動脈炎は大型血管炎に含まれる肉芽腫性血管炎である。以前は側頭動脈炎として認識されていたが，側頭動脈だけでなく，頭蓋外領域の中型〜大型血管も障害する。診断にはまず本疾患を疑うことが重要であり，血液検査，画像，組織などいくつかの検査所見を組み合わせて診断する。転帰に大きく影響する失明や片麻痺などの神経症候，大動脈瘤などを引き起こすため早急な診断と治療介入が不可欠である。

Abstract

Giant cell arteritis (GCA), also referred to as temporal arteritis, is a variant of large-vessel vasculitis. GCA should be considered in the differential diagnosis in patients aged ＞50 years, who present with headache, abrupt onset of visual disturbances, unexplained fever, a high erythrocyte sedimentation rate, and high serum C-reactive protein levels. Diagnosis of GCA is based on accurate interpretation of laboratory data, temporal artery biopsy findings, and imaging study results. Imaging modalities used for GCA include positron emission tomography, computed tomography (CT), CT angiography, and conventional magnetic resonance angiography. Biopsy is the gold standard for diagnosis of GCA. Glucocorticoids (GCs) are used as standard treatment to induce remission and also for maintenance therapy. However, clinicians should be aware of the adverse effects of GC treatment, including hyperglycemia, an immunocompromised state, and delirium. If adverse effects outweigh the benefits of GC treatment, it is necessary to consider switching to or adding an immunosuppressant to the therapeutic regimen.