Hypouricemia and renal tubular acidosis in primary biliary cirrhosis

A 51-year-old woman with primary biliary cirrhosis developed distal renal tubular acidosis and hypouricemia (1.4 mg per 100 ml) in the course of hepatic injury. Her renal clearance of uric acid reached 33.7 ml/min (mean +/- SD in five normal age-matched women: 9.2 +/- 3.1 ml/min). Pyrazinamide, an inhibitor of uric acid secretion, considerably reduced the uric acid clearance, while it was not enhanced by probenecid, a blocker of uric acid reabsorption. Thus, the hypouricemia may have been due to a defect of postsecretory reabsorption of uric acid in the renal tubules. The present case emphasizes the significance of hypouricemia and hyperuricosuria as indicators of renal tubular injury in primary biliary cirrhosis.