Pembrolizumab-associated nephrotic syndrome recovered from transient hemodialysis in a patient with lung cancer.

A 70-year-old man diagnosed with lung adenocarcinoma was referred to our department for an evaluation of acute onset of nephrotic syndrome with acute kidney injury (AKI) after the 7th course of pembrolizumab treatment. Renal biopsy could not be performed, because he needed anticoagulation therapy for venous thrombosis. Pembrolizumab was discontinued, and prednisolone was started. Hemodialysis was also started, because oliguria was not resolved, and dyspnea due to pulmonary congestion appeared even with the high dose of diuretics. Hemodialysis was successfully withdrawn within 5-week duration because of renal function recovery and increase of urine volume. Complete remission was achieved 4 months after initiating prednisolone. He has never experienced hemodialysis again and remains remission of nephrotic syndrome even the dose of prednisolone was tapered for 8 months. Renal pathology in the current case was uncertain. However, minimal change disease seemed to be a plausible cause of nephrotic syndrome with AKI because of a good response to steroid therapy and acute onset of nephrotic syndrome. In addition, renal pathology in all of the reported cases of pembrolizumab-associated nephrotic syndrome with AKI was minimal change disease. Our case shows for the first time that renal function could be reversible with prednisolone in pembrolizumab-associated nephrotic syndrome with severe AKI even after progression of renal failure which needs dialysis.