Abstract
We report a case of renal hypouricemia associated with acute renal failure. A 16-year-old boy was transferred to our hospital because of azotemia after exercise. He had been well until three days prior to admission, when he had developed nausea, anorexia, vomiting and oliguria following exercise. No loin pains or limb muscle tenderness developed, and macroscopic hematuria was not observed. On admission to the first hospital he was alert and had no edema and his blood pressure was within the normal range. Serum urea-N (BUN) and creatinine (s-Cr)levels were 47 and 6.1mg/dl, respectively. He was then transferred to our hospital for further examination, where, because no obvious causes of acute renal failure could be found, he received no aggressive therapy other than fluid replacement and bed rest. After admission urine output gradually increased from 600 to 3,000ml/day, and BUN and s-Cr levels decreased to within the normal range. Serum uric acid level was surprisingly low,3.8mg/dl, in spite of the elevated BUN and s-Cr levels, and then decreased to below 1.0 mg/dl after the recovery of renal function. Urine urate excretion was 770mg/day and urate clearance rate was as high as 76.4ml/min, and these rates, did not change after oral administration of benzbromarone and pyrazinamide. We did not find any depositions of urate in the tubular lumen of renal biopsy specimens. His father and two brothers also had hypouricemia and increased urate clearance.
We speculate that urine urate excretion could have been accelerated after exercise by the increased production of uric acid which resulted in acute urate nephropathy.
