[Uric acid, kidney disease and nephrolithiasis]

Different types of kidney disease are known to be associated with hyperuricemia. The underlying pathophysiologic mechanisms strongly vary, and different ways of therapeutic approach are therefore required. In tumor lysis syndrome, a rapid, excessive increase of serum uric acid level can cause an acute renal failure. For chronic urate nephropathy, on the other hand, constantly elevated serum uric acid level for a longer period seems to be important. Being still controversial as a disease entity however, the aetiology for putative chronic urate nephropathy might be in fact chronic lead intoxication, as suggested by quite an amount of association data. In terms of uric acid nephrolithiasis, the major risk factor is a urinary acidification defect with persistently acidic urine pH, and not necessarily hyperuricemia or hyperuricosuria. Evidence suggests that metabolic diseases with increased insulin resistance are strongly associated with urinary acidification defect. Patients with uric acid kidney stones should therefore be thoroughly evaluated for such metabolic diseases and in a positive case adequately treated.