Diabetic ketoacidosis shortly after COVID ‐19 vaccination in a non–small‐cell lung cancer patient receiving combination of PD ‐1 and CTLA ‐4 inhibitors: A case report

We describe a case of diabetic ketoacidosis (DKA) shortly after the SARS-CoV-2 (COVID-19) vaccination in a 65-year-old woman with non-small-cell lung cancer under a combination treatment of programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors. She had no history of diabetic mellitus. A few days after the second shot of COVID-19 vaccination, she developed DKA. We speculate that the immune-related adverse event and immunogenicity of vaccination synergistically induced DKA.