Abstract
A woman in her 50s who had lupus nephritis (LN ; type Vb) was treated with prednisolone (10 mg/day). Her serum levels of creatinine (Cr) and uric acid (UA) were around 1.2 mg/dL and 8.0 mg/dL, respectively. In the middle of October 2005, mizoribine (MZ ; 50 mg/day) was started due to LN relapse. She, however, discontinued MZ on day 4 of administration because of nausea and loss of appetite. Despite the withdrawal, she noted worsening of general medical conditions. Then two weeks later, she developed an oliguric state, acute renal failure (ARF ; Cr 14.2 mg/dL) and hyperuricemia (UA 25.1 mg/dL). Serum MZ concentration was detected at 0.43 μg/mL even 2 weeks after the withdrawal of MZ. ARF was thought to have been caused by hyperuricemia concomitant with uric acid nephropathy as an adverse effect of MZ. Hemodialysis (HD) was performed and her renal function recovered to the previous level. In this case, a vicious cycle consisting of prolonged MZ metabolism, hyperuricemia and progressive renal dysfunction is thought to have influenced the development of uric acid nephropathy and oliguric ARF.
