Hypouricemia due to Renal Tubular Defect-Reply

With reference to the comments by Dr Gaspar and his co-workers on our article "Hypouricemia due to renal tubular defect" 1 we would like to point out that the discrimination between the different urate tubular defects was scrupulously described in the "Comment" section of our article. The Table presented by Dr Gaspar and his co-workers reports data in contradiction to the accepted interpretation of the combined probenecid-pyrazinamide test, eg, in defective proximal presecretory reabsorption, uric acid excretion is affected only slightly ( 2 In defective postsecretory reabsorption, pyrazinamide administration markedly decreases uric acid excretion. 3,4 In total loss of urate reabsorption capacity, administration of pyrazinamide and probenecid decreases the clearance ratio of urate to creatinine to a value of 1.0%. 3 Ten relevant references reported by Dr Gaspar were included in our paper. Their reference no. 12 5 could not be reported since it appeared only as a letter