A case of diabetic ketoacidosis triggered by immune checkpoint inhibitors in the treatment of recurrent nasopharyngeal carcinoma.

Immune-related adverse events (irAEs) caused by immune checkpoint inhibitors (ICIs) have been widely documented. Diabetic ketoacidosis (DKA), a severe irAEs, has not been previously reported in patients with nasopharyngeal carcinoma (NPC). This case report describes the development of DKA during maintenance immunotherapy with tislelizumab in a patient with recurrent NPC. A 41-year-old female patient with recurrent NPC (rT3N0M0, 8 th edition of AJCC staging) experienced DKA during her 13 th session of maintenance treatment with the ICI tislelizumab. After urgent consultation with an endocrinologist, immune-related DKA was diagnosed, and immune checkpoint inhibitor-related diabetes was confirmed. Prompt treatment with hypoglycemic agents, fluid infusion, and correction of water-electrolyte and acid-base balance was administered. The patient's blood glucose was stabilized within 6 days, and she was discharged without complications. This is the first reported case of DKA in a patient with NPC receiving tislelizumab maintenance immunotherapy. Clinicians should enhance their understanding and monitoring of adverse events in patients treated with ICIs, focusing on early diagnosis and appropriate intervention.