The blood, urine and cerebro-spinal fluid were sterile on culture. On follow up at 3 months the infant has a small calculus in the right renal pelvis, is growing well and is still on allopurinol. Post-renal failure can occur following posterior urethral valves. Intrinsic renal failure is rare and can occur following renal vein thrombosis, or exist as in renal dysplasia. Uric acid is a nephrotoxin and causes intrinsic renal failure.
Uric acid appears to be nearly completely filtered by glomerular membrane.
Reabsorption of filtered uric acid occurs early in the proximal convoluted tubule. Post-secretory reabsorption of uric acid also occurs. Up to about twice the normal plasma concentrations of creatinine, the plasma concentration of uric acid increases approxi-mately in parallel with creatinine. However, this test cannot be employed in children since this ratio normally exceeds 1.0 during childhood. Enhanced renal capacity for urate secretion during childhood may account for the rarity of gout in children.