A Patient with Atezolizumab-Induced Autoimmune Diabetes Mellitus Presenting with Diabetic Ketoacidosis

Background: Atezolizumab, an immune checkpoint inhibitor, is a humanized monoclonal, anti-programmed death ligand 1 (PD-L1) antibody used for the treatment of metastatic urothelial carcinoma that has progressed after chemotherapy. Case Presentation: We describe patient with known history who presented diabetic ketoacidosis 6 weeks following his second cycle atezolizumab. His serum lactate level was slightly elevated (2 mM) and ?-hydroxybutyrate (3.9 mM). High anion gap metabolic acidosis secondary to diagnosed. Subsequent testing demonstrated hemoglobin A 1c 9.9%, positivity anti-glutamic acid decarboxylase (0.03 nM, reference range <0.02 nM), suppressed C-peptide (0.1 ?g/L, 0.9–7.1 ?g/L) in absence detectable anti-islet antigen 2 (IA-2) or anti-insulin antibodies. initial management included cessation atezolizumab treatment, intravenous sodium chloride administration, insulin pump infusion, which gradually resolved. The subsequently switched Protaphane at 18 units before breakfast 8 dinner, together metformin 1000 mg twice daily. Four later medication changed human isophane plus neutral (70%/30%; Mixtard 30 HM; 26 units/4 units). Linagliptin 5 added month later. declined 8.1% year Conclusions: PD-L1 inhibitors can induce type diabetes, patients present ketoacidosis. Blood glucose levels should be regularly monitored are prescribed these medications.