Reversal of Severe Volume Deplete Acute Kidney Injury by Rasburicase

We report on a case of acute kidney injury in a patient with severe volume depletion from high ileostomy output and poor oral intake associated with hyperuricemia and hyperkalemia. The patient presented with similar features on three separate admissions. A conservative management approach was undertaken that included infusion of rasburicase, since the patient refused to undergo hemodialysis on each occasion. Rasburicase is a recombinant urate oxidase enzyme that converts uric acid to allantoin which is five to ten times more soluble than uric acid in urine, thereby enhancing urinary excretion. Rasburicase was administered each time and was followed by a prompt increase in urine output, rapid decrease in serum uric acid level, and recovery of renal function without the need for acute renal replacement therapy. We believe that rasburicase, with a molecular weight of 34 kDa, crossed the glomerular filtration barrier and entered the tubular fluid where it dissolved intra-tubular uric acid, thus relieving obstruction, thereby rapidly enhancing urine excretion and improving renal function. Based on this experience, we propose that rasburicase offers an alternative treatment for acute kidney injury in similar types of settings. To the best of our knowledge this is the first reported case in this situation.