Acute Kidney Injury after Pembrolizumab-Induced Adrenalitis and Adrenal Insufficiency.

Pembrolizumab is an immune checkpoint inhibitor that targets the programmed cell death protein 1 (PD-1) antigen and induces an immune response against tumor tissues. It has been successful in inducing remission in patients with severe metastatic disease, often refractory to other chemotherapeutic agents. The risk of injury of other organ systems has been noted with reported cases of glomerular disease and endocrine disease. In addition, hypophysitis as well as dermatological and gastroenterological side effects have been reported. Renal injury with immune checkpoint inhibitors like nivolumab and pembrolizumab is usually mediated via interstitial nephritis, though glomerular disease presentations like anti-neutrophil cytoplasmic antibody-associated vasculitis, immune complex disease, and thrombotic microangiopathy have also been reported. We report a 70-year-old Caucasian male who underwent treatment with pembrolizumab for adenocarcinoma of the lung. He developed acute adrenal insufficiency and concomitant severe hypotension upon presentation. He did not require renal replacement therapy, rather his severe acute kidney injury resolved with hydration, normalization of blood pressures with vasopressors, and treatment with high-dose corticosteroids. His urinary indices (fractional excretion of urea, FEUrea) and clinical course were highly suspicious for acute tubular necrosis that resolved quickly after treating his underlying adrenalitis. The urinary sediment, proteinuria, and clinical course were not typical for the usually expected renal lesion of interstitial nephritis in patients treated with immune checkpoint inhibitors.