Uric acid and the kidney

Since the primary site of excretion of uric acid is the kidney, plasma concentration of uric acid is mainly determined by renal handling of uric acid. Although hyperuricemia is common in various spectrum of kidney diseases, it historically has been viewed as an issue of limited interest. Recently uric acid has been resurrected as a potential contributory risk factor in the development and progression of renal disease via its direct effect on renal vasculature and tubules as well as indirect effect mediating hypertension and metabolic syndrome. Most studies documented that an elevated serum uric acid level independently predicts the development of chronic kidney disease (CKD), and several interventional studies demonstrated the beneficial effect of lowering plasma uric acid concentrations on preservation of renal function. Uric acid can also induce acute uric acid nephropathy and renal stone via different mechanisms from the progression of renal disease in CKD. In this chapter, the various spectrum of renal disease in hyperuricemic subject will be discussed with a comprehensive review of uric acid-lowering therapy including the use of xanthine oxidase inhibitor and uricosuric agents.