Fulminant Diabetes in a Patient with AdvancedMelanoma on Nivolumab

Anti-PD-1agentswereapprovedforadvancedmelanomaafterthelandmarktrialCheckmate-037.Anti-PD-1agentscan breach immunologic tolerance. Fulminant diabetes is an immune endocrinopathy that results from a violent immune attackleading to complete destruction of pancreatic beta cells in genetically predisposed people. We present a rare case of fulminantdiabetes precipitated by anti-PD-1 immunotherapy.Case. A 61-year-old male with advanced melanoma presented with a three-day history of nausea, vomiting, and malaise. He was started on nivolumab and ipilimumab. After the third dose, he developeda generalized rash and was prescribed high-dose prednisone. Labs revealed potassium 9.5mmol/L, sodium 127mmol/L,bicarbonate<10mmol/L, blood glucose 1211mg/dL, anion gap>31mmol, arterial blood pH 7.14, and beta-hydroxybutyrate13.7mmol/L.Hewasdiagnosedwithdiabeticketoacidosis.HemoglobinA1Cwas6.9%.C-peptidewasundetectable(<0.1ng/ml).Glutamic acid decarboxylase autoantibodies, zinc transporter 8 autoantibodies, insulin autoantibodies, islet antigen 2 auto-antibodies, and islet cell antibodies were all negative.Conclusion. Anti-PD-1 immunotherapy is effective in cancers refractory tostandard chemotherapy. )ese agents can precipitate autoimmune disorders. As the use of anti-PD-1 agents is expected to rise,physicians should be educated about the potential side effects. We recommend conducting routine blood glucose checks inpatients on these agents