Euglycemic DKA as an Initial Presentation of Immunotherapy-Induced Insulin-Dependent Diabetes

Abstract

New onset insulin dependent diabetes (DM) has been reported in cancer patients (pts) receiving immunotherapy (IO). Typically, pts have Grade 3 hyperglycemia (CTCAE) and sometimes DKA. Euglycemic DKA has been reported in pts on empagliflozin (Empa). We present a unique case of euglycemic DKA as initial presentation for immunotherapy induced insulin dependent DM. Pt is a 68 year old man without preexisting DM started on nivolumab for metastatic prostate cancer. Following 2 doses of nivolumab, he developed fatigue, weight loss and Grade 2 hyperglycemia for which he was started on metformin, glipizide, and Empa by his outside physician. His BG levels ranged from 130-200 mg/dL on these therapies. Nivolumab treatment was stopped due to significant adverse effects. On return visit to our clinic, approximately 3 months after initial hyperglycemia, pt complained of persistent fatigue, weight loss and a new fruity odor in his breath. Labs revealed BG of 134mg/dl, bicarb of 19 mEq/L (23-30mEq/L), anion gap (AG) of 17mEq/L (4-14mEq/L). Urine ketones were positive and c-peptide level was 0.3ng/ml (0.8- 3.85ng/ml). Pt was advised to immediately stop Empa and follow-up with local ER. When he presented to local ER, approximately 4 days later, he was hyperglycemic with glucose 316 mg/dL, and labwork consistent with classic DKA. Pt was initiated on basal bolus insulin regimen and had resolution of DKA.IO mediated DM results from immune mediated islet cell destruction leading to rapidly progressive insulin deficiency. When suspected, these pts should be evaluated for beta cell dysfunction and insulin should be used for glycemic control. This case highlights that SGLT2 therapy should be used with caution in patients with hyperglycemia on immunotherapy as it could mask the diagnosis of DKA. In addition, this case shows that patients taken off of immunotherapy may develop delayed glycemic complications and may need long term monitoring. Disclosure P. Iyer: None. S.N. Thosani: Consultant; Spouse/Partner; Boston Scientific Corporation, Medtronic. Speaker's Bureau; Spouse/Partner; AbbVie Inc..