A Rare Presentation Of Checkpoint Inhibitor Induced RTA

Immune checkpoint inhibitors have opened a new era in the treatment of advanced malignancies, resulting in increased use and remarkable clinical responses. However, there has been an increase in the incidence of immune-related adverse events as a result of the immunologic effects of these therapies. Kidney immune-related adverse events incidence is reported as low at 2% to 5%¹. Renal toxicity commonly described includes acute interstitial nephritis, minimal change disease, immune complex glomerulonephritis². Renal tubular acidosis (RTA) has occasionally been reported but is uncommon. We report a patient with a known history of metastatic melanoma undergoing treatment with Ipilimumab + Nivolumab who developed an RTA and was successfully treated with stress dose steroids and sodium bicarbonate. To date, there are a limited number of reports describing immune-related adverse events causing RTA. We describe the clinical characteristics, potential mechanisms, and management of patients who develop an immune-related RTA.