Improvement in urate nephrolithiasis with pegloticase in gout

Gout is frequently associated with nephrolithiasis. Uric acid nephrolithiasis in gout correlates with the degree of hyperuricemia and hyperuricosuria. A decrease in serum and tissue uric acid burden may result in improvement in uric acid nephrolithiasis in patients with gout. We present a case of severe chronic tophaceous gout with recurrent uric acid nephrolithiasis who had a remarkable improvement in his gout, as well as the resolution of uric acid renal calculi after treatment with pegloticase. Pegloticase has been approved for the treatment of chronic gout refractory to conventional therapy, however, its effects on uric acid nephrolithiasis have not been evaluated. Our case is first such reported case, and further studies evaluating the efficacy of pegloticase in improving uric acid calculi are needed to confirm our findings.