急性腎不全を発症したレジオネラ肺炎の1例

A Case of Legionella pneumonia Associated with Acute Renal Failure

要旨　患者は41歳，男性．発熱を主訴に受診した．胸部CT検査にて右肺底区に浸潤影を認め入院となった．白血球数11,750/mm³，CRP27.08mg/mlと著明に上昇していたため，3剤併用(CTRX，MINO，LVFX)にて化学療法を開始した．翌日，尿中レジオネラ抗原陽性と判明したため，CTRXをRFPに変更した．その後，炎症所見は著明に改善したものの，腎機能障害が出現し，BUN78.0mg/dl，Cre6.26mg/dlまで上昇した．血中CPK値は正常で，横紋筋融解症は認めなかった．腎生検では，腎組織への好中球の浸潤を認めたものの，糸球体，尿細管，間質に異常所見は認められなかった．血清K値は正常で，尿量も確保されていたため人工透析を施行することなく，約3週間で腎機能は正常化した．レジオネラ肺炎の重篤性を知るうえで貴重な症例であったので，文献的考察を加えて報告した．

　A 41-year-old man was admitted to our hospital with pyrexia up to 40℃. Chest X-ray film showed infiltration of the right lower lung field. As the urine sample was positive for the Legionella antigen, the therapy of LVFX, MINO and RFP administration was started. Although his general condition improved, renal function has gradually deteriorated without an increase in CPK level. Renal biopsy revealed an infiltration of neutrophils into renal tissues. Finally, the patient recovered from renal dysfunction without induction of hemodialysis. We suppose that early diagnosis might lead to proper chemotherapy. Histological findings of this case suggest that in Legionella pneumonia case several factors including dehydration, shock, endotoxemia, NSAIDs administration and direct microbial toxicity could cause renal dysfunction.