Exercise-induced acute renal failure in a girl with renal hypouricemia

A 10-year-old Japanese girl developed acute renal failure following a 100-meter dash during physical training at school. After the run, she experienced intense pain in the loins with nausea and vomiting lasting more than 12 h. On the following morning, she was found to have mild proteinuria and acute renal failure (ARF). Serum creatinine and blood urea nitrogen were elevated, but the serum uric acid level was normal (3.1 mg/dL). With recovery of renal function over the ensuing days, hypouricemia (0.6 mg/dL) became evident in the patient. Although the pathophysiological association between renal hypouricemia and ARF is not known, oxygen free radicals have been implicated in the pathogenesis for ischemic-reperfusion ARF. Superoxide production by neutrophils stimulated by N-formyl methionine leucyl-phenylalanine was normal in the patient both before and following exercise. Pyrazinamide and probenecid tests were undertaken on both the patient and her parents, who had borderline hypouricemia, to determine their renal tubular handling of uric acid. Results showed that the patient and her mother had a subtotal reabsorption defect, while the father had defective postsecretory uric acid reabsorption.