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Internal Medicine

Training Level

Resident PGY 2


Henry Ford Macomb


Immune checkpoint inhibitors have been shown to be an essential part of cancer treatments, however there have been reported immune related adverse events. Type 1 diabetes was reported in only 0.1% of the patients in clinical trials of Pembrolizumab, a programmed cell death 1 (PD-1) inhibitor. We present a case of pembrolizumab associated DKA in a previously nondiabetic. Patient is a 75yo male with a history of carcinoma in situ of the bladder, prostate cancer, carcinoma of unknown primary (had been on Atezolizumab, Taxotere), CKD presents to the hospital with fatigue, weakness and diarrhea. Of note, the patient was recently started on carboplatin/taxotere/keytruda 1 month prior. Initial labs were indicative of DKA with lactic acidosis, elevated anion gap, beta-hydroxybutyrate 10.22, glucose 1,884, pH 7.12. Patient was placed on insulin drip, improved and transitioned to subcutaneous insulin. Workup during hospitalization revealed low levels of C-peptide; however, islet-cell antibodies, insulin antibodies, glutamic acid decarboxylase antibodies were all within normal limits. Hemoglobin A1c 7.9 and lipase were noted to be elevated at 162IU/L. Pembrolizumab blocks and prevents binding of tumor cells to PD-1 on lymphocytes allowing T-cell mediated destruction. However, because of non specificity, non-cancerous cells are also affected. In animals, Pembrolizumab has been shown to act on beta islet cells of the pancreas and cause subsequent destruction of insulin producing cells. Cases such as this stress the importance of monitoring patients for signs and symptoms of diabetes when starting immunotherapy such as pembrolizumab.

Presentation Date


Pembrolizumab (Keytruda®) Associated Diabetic Ketoacidosis in a Previously Nondiabetic Patient