Renal tubular hypouricemia: evidence for defect of both secretion and reabsorption

Abstract

Two patients had hypouricemia due to increased uric acid clearance. They showed no decrease of urate clearance to creatinine clearance ratio (Cua/Ccr) following pyrazinamide administration, and no increase of Cua/Ccr after probenecid. One patient showed a limited decline in Cua/Ccr after intravenous furosemide. In the other patient, neither acetylsalicylate nor furosemide produced any noticeable change in Cua/Ccr. Both showed a normal diuretic response after intravenous furosemide. The results indicate that they had massive defects in urate transport along the nephron, probably including both secretion and reabsorption.