Anti PD-1 monoclonal antibody induced autoimmune diabetes mellitus: a case report and brief review

Nowadays, immune checkpoint inhibitor therapy has been used in more and more cancer patients. These agents were associated with immune-related adverse effects, and autoimmune diabetes mellitus is one of them. And it is not common but can be potentially fatal. Anti PD-1 monoclonal antibody is a humanized IgG4 antibody against PD-1, which has been applied in advanced non-small cell lung cancer (NSCLC) treatment. In this paper, we reported the case of autoimmune diabetes mellitus induced by anti PD-1 monoclonal antibody in NSCLC treatment. Here is a 73-year-old male patient with no diabetes history who had anti PD-1 monoclonal antibody 200 mg every 3 weeks for NSCLC treatment. After 10 cycles of the therapy, his blood glucose level elevated and he suffered diabetic ketoacidosis (DKA). And his C-peptide was significantly decreased with negative relative auto-antibodies. Combined with his medical history and the laboratory examination, anti PD-1 monoclonal antibody induced autoimmune diabetes mellitus was diagnosed. After recovering from DKA and controlling his blood glucose, his anti PD-1 therapy was continued and he still got some benefit. This report suggested that glycemic monitoring is imperative during this anti PD-1 monoclonal antibody treatment. Moreover, after controlling the blood glucose level, continuing the immune therapy could still be benefit and safe for the patient.