クローン病患者にみられた尿酸アンモニウム結石症の1例

Abstract

28歳女.左腰背部疝痛を主訴とした.15歳時にクローン病と診断されていた.脱水症と低栄養との診断で点滴加療を受け, その約5ヵ月後に尿路感染症を発症した.その後, 主訴症状が出現し, 腹部エコーにて左水腎症と左腎結石を認めた.血液検査では軽度低アルブミン血症を認め, 尿検査では潜血陽性と血尿を認めた.KUBでは結石像はみられず, 腹部単純X線CT検査で左腎盂の拡張と左腎盂尿管移行部に石灰化陰影を認めた.左腎盂尿管移行部結石と診断し, 計10回のESWL施行にてほぼ完全な砕石を得た.排石された結石の成分は赤外線吸収スペクトラムにより尿酸アンモニウム98%であった

A 28-year-old woman suffering from Crohn's disease since 15 years of age presented with left back pain. She had undergone a colectomy when she was 20 years old and an ileostomy when she was 25 years old. She had been treated with mesalazine and pernasal nutrition (Elental) Ultrasonography showed left side hydronephrosis and a renal stone in the left renal pelvis. Computed x-ray tomography revealed a stone measuring 1.5 x 1.0 cm2 at the ureteropelvic junction, which was radiolucent on an abdominal radiograph. The renal stone was successfully treated with 10 exposures of extracorporeal shockwave lithotripsy. Ninety eight percent of the passed stone was composed of ammonium urate. Crohn's disease-related poor nutrition and dehydration are presumed to have been possible induction factors in the forming of the ammonium urate stone in this case.