Exercise-induced acute renal failure in a patient with renal hypouricemia.

We describe a case of exercise-induced acute renal failure (ARF) in a patient with hypouricemia. Following recovery from ARF, the patient's serum urate concentration was 0.6-0.9 mg/dl, and the ratio of urate clearance to creatinine clearance (Cua/Ccr) was 41.9%-56.6%. There was no change in the Cua/Ccr following the administration of pyrazinamide or probenecid, suggesting defects of tubular urate/anion exchangers. Because the renal biopsy revealed acute tubular necrosis without uric acid crystals, the ARF of this patient might be due to oxygen free radicals resulting from exercise stress and hypouricemia.