小脳失調および急性腎不全で発症したレジオネラ症の1剖検例

An Autopsy Case of Legionellosis Complicated with Cerebellar Ataxia and Acute Renal Failure

　症例は64歳，男性．頭痛，ふらつきを主訴に当院を受診，小脳失調を認め入院した．入院後主訴は改善するも，第6病日より呼吸困難が出現し，両肺野の間質影を伴う浸潤影を認めた．また，血清creatinin値が9.2mg／dlと上昇（入院時1.1mg／dl），血液透析を施行し離脱した．臨床像よりレジオネラ症を疑い抗生剤（erythromycinなど）を投与した．血清抗体価（serogroup 1）は64倍以下が128倍に上昇し診断確定した．ステロイドパルス療法を併用し肺炎の改善がみられたが，ステロイド中止後急速に呼吸不全が増悪し人工呼吸器を装着．その後も改善なく第54病日死亡．剖検では肺は器質化肺炎で間質および肺胞内線維化がみられた．レジオネラは鍍銀染色で陰性．腎は尿細管の拡張を認めた．中枢神経症状，腎不全を合併した肺炎ではレジオネラ症を念頭におくことが重要であると思われた．

A 64-year-old man was admitted to our hospital because of cerebellar ataxia. Serum creatinin was 1.1 mg/dl and hyaline cast was seen. Ataxia soon im-proved, but on the sixth day he complained of dyspnea and Laboratory data revealed acute renal failure (s-creatinin 9.2 mg/dl). Chest X-ray showed infiltrative and interstitial shadows. We diagnosed the illness as Legionellosis and initiated hemodialysis. Erythromysin and Rifampisin were used in combination with steroid therapy. The patients symptoms improved and steroid was tapered. After cessation of the steroid therapy. however, his respiratory status deteriorated and mechanical ventilation was required. Serum titers of Legionella pneumophilia (serogroup 1) via indirect immunofluoresence (IFA) increased from less than 1 : 64 to 1 : 128, comfirming the diagnosis. On the 54th hospital day, the patient died of respiratory failure. At autopsy. both lungs showed extensive intraalveolar and intraductal fibrosis, though Legionella were not dis-covered on silver impregnation preparations. The kidneys showed dilated convoluted tubuli.