Uric acid excretion and renal function in the acute hyperuricemia of leukemia. Pathogenesis and therapy of uric acid nephropathy

Uric acid excretion and discrete renal functions were measured in forty-three studies performed on twenty-six patients with active leukemia. Patients with hyperuricemia had an increased urinary excretion rate and urinary concentration of uric acid. The increase in uric acid excretion associated with acute endogenous hyperuricemia promotes uric acid precipitation in the acid, concentrated urine of the distal tubules and collecting ducts, with resultant obstruction of nephrons. In hyperuricemic patients, there was a diminished clearance of C¹⁴-labeled inulin (C_inulin) usually with minimal depression of para-aminohippurate clearance (C_PAH). The rapidly reversible nature of uric acid nephropathy suggests that the lesion is primarily obstructive. Successful prophylaxis as well as therapy of uric acid nephropathy depends on effective urinary alkalinization and a brisk urine flow, in order to attain maximal solubility of uric acid. A regimen to accomplish the foregoing, through administration of acetazolamide, sodium bicarbonate and intravenous hydration, is outlined.