Exercise-induced acute renal failure observed in a boy with idiopathic renal hypouricemia caused by postsecretary reabsorption defect of uric acid

Acute renal failure without oliguria developed in an 11-year-old boy after running exercise. With improvement of his renal function, marked hypouricemia became apparent (0.8-0.9 mg / dl). Increased excretion of uric acid into the urine, increased clearance ratio of uric acid against creatinine ( CUA/ CCr), normal concentration of plasma xanthine and hypoxanthine, and suppression of CUA/ CCr ratio by pyrazinamide loading but not by probenecid, were observed in the patient and his two siblings, suggesting that hereditary abnormalities of reabsorption of uric acid after secretion from the renal tubules resulted in the hypouricemia. The mechanism of acute renal failure in this disease remains unknown.