Renal Hypouricemia with Both Drug-Insensitive Secretion and Defective Reabsorption of Urate: A Novel Type of Renal Hypouricemia

Renal handling of urate in the hypouricemic patient with increase in both urate clearance (Cur) and Cur/creatinine clearance (Ccr) and normal urinary excretion of urate was studied according to the pharmacological evaluation. In the present case there was no response of urate excretion to either pyrazinamide or probenecid. Both furosemide and prednisolone could not alter Cur and Cur/Ccr. Administration of inosine could have increased Cur, which was greater than Ccr. These results suggest that the present case had the defect of both pre- and postsecretory reabsorption of urate, accompanied by the existence of drug-insensitive secretion of urate, which is different from hitherto known types of renal hypouricemia, i.e. a novel type of renal hypouricemia.