[Checkpoint inhibitor induced diabetes mellitus].

Area of Science:

• Oncology
• Immunology
• Endocrinology

Background:

• Checkpoint inhibitors are novel immunotherapies targeting cancer.
• Pembrolizumab is an immune checkpoint inhibitor used in cancer treatment.
• Immune checkpoint inhibitors can modulate immune responses, potentially affecting endocrine functions.

Purpose of the Study:

• To report two cases of new-onset type 1 diabetes mellitus (T1DM) in patients treated with pembrolizumab.
• To highlight ketoacidosis as a potential initial presentation of T1DM in this context.
• To emphasize the importance of recognizing hyperglycemia symptoms in patients receiving checkpoint inhibitors.

Main Methods:

• Case report of two patients presenting with severe ketoacidosis.
• Review of patient history, including recent initiation of pembrolizumab therapy.
• Assessment of glycemic markers (HbA1c) upon presentation.

Main Results:

• Two patients developed severe ketoacidosis, the first sign of diabetes, weeks after starting pembrolizumab.
• One patient's HbA1c was not elevated on presentation, indicating acute onset diabetes.
• These findings suggest a link between pembrolizumab and new-onset T1DM.

Conclusions:

• Type 1 diabetes mellitus is a rare but serious complication of checkpoint inhibitor therapy.
• Routine glucose or HbA1c monitoring may not be effective for early detection in these patients.
• Healthcare providers and patients must be vigilant for hyperglycemia symptoms to prevent diabetic ketoacidosis.