Endocrine Abstracts

We present a unique case of Pembrolizumab induced adrenal insufficiency. A 65 year old lady was admitted with septic shock secondary to chest infection. She was 3 weeks post neo adjuvant chemotherapy plus immunotherapy for triple receptor negative solitary Right sided breast cancer. She has Type II Diabetes mellitus, hypercholesterolemia and varicose veins. She takes Metformin and Atorvastatin. She is single, with no significant family history. On intravenous antibiotics her biochemical parameters improved, however she remained very unwell with persistent nausea, dizziness. Her 9 am Cortisol was noted to be low at 52 nmol/l. She was immediately started on steroids and her clinical condition improved over the next 24 h. A full pituitary profile has been requested, ACTH report awaited. A short Synacthen test confirmed adrenal insufficiency, 9am Cortisol 76 nmol/l with Cortisol values of 133 nmol/l and 138 nmol/l at 30 and 60 minute intervals post Synacthen respectively. She was advised about long term steroid use and precautions. Pembrolizumab is an immune checkpoint inhibitor used in the treatment of various cancers. Pembrolizumab induced adrenal insufficiency is autoimmune mediated affecting the pituitary gland. The incidence of adrenal insufficiency is reported after the Pembrolizumab is used for various months. This is a unique presentation in our case, as the patient received a single doses of Pembrolizumab and developed adrenal insufficiency.