Key points are not available for this paper at this time.
Abstract Disclosure: S. Shankar: None. S.S. Sundar: None. M.S. Vaishnav: None. L. Lekkala: None. K. Thummala: None. S. Srikanta: None. T. Deepak: None. R.B. Vijay: None. K. Muniraj: None. V. Nath: None. C. Siddlingappa: None. P. Ravikumar: None. M.D. Chitra: None. Introduction: Autoimmune hypophysitis caused by immune checkpoint inhibitors ICIs; anti-CTLA-4 (Ipilimumab alone 7.9%), anti-PD-1 (Pembrolizumab alone 1.7%; nivolumab alone 0%) are being increasingly documented, with anterior hypopituitarism affecting corticotrophs more commonly than thyrotrophs and gonadotrophs (large time span of onset; different recovery patterns). Clinical Case 2021 Sep Age 65 years (type 2 diabetes, hypertension). Renal Cell Carcinoma S/P radical nephrectomy. 2023 Jul PET-CT= Metastatic pleuropulmonary nodules. Four admissions to Specialist Oncology Hospital Four 2 weekly cycles of Inj Pembrolizumab 200 mg (with Tab Axitinib 10 mg/day). After first cycle: progressive fatigue, body aches, drowsiness. S Sodium= Pre-pembrolizumab= 137 mEq/L (135-145); Post-pembrolizumab= 124, 134, 132, 124; T3= 1.63 to 0.60 to 1.24 to 1.35 ng/mL (0.97-1.69); T4= 6.83 to 4.93 to 10.44 to 11.44 mcg/dL (5.53-11); TSH= 10.46 to 6.28 to 5.39 to 9.48 mIU/mL (0.46-4.68); S Cortisol 8 am= 1.54 mcg/dL (5-25); S Potassium= 4.59 mEq/dL (3.5-5.1)]. One episode of loss of consciousness; EEG= abnormal; MRI Brain= normal. During every hospital admission, oncology, medical, endocrinology and nephrology teams attributed the same to “illness” (no specific diagnosis) and provided symptomatic treatment (IV 3% saline, tolvaptan and sodium bicarbonate tablets).2023 Nov Medicine: Very severe nausea, anorexia, generalised weakness, myalgia, hiccoughs, and inability to walk. Frustrated family members sought admission in “new” General Hospital. S Sodium= 119, 120; S Potassium= 4.8; S Creatinine= 1.67 mg/dL (0.7-1.3); S Uric acid= 4.5 mg/dL (4.40-7.60); Urine spot Sodium= 84 mmol/L; ESR= 144 mm. Endocrinology: S Cortisol 8 am= 0.09 mcg/dL;S Cortisol post 250 mcg Inj Synacthen= 3.76 (20);Plasma ACTH= 5.4 pg/ml (9-52). S T3= 1.35; S T4= 11.44; S TSH= 9.48; LH= 3.61mIU/mL (1.5-9.3); FSH= 1.4mIU/mL (1.4-18.1); PRL= 30.1 (2.6-13.3); Testosterone total= 314 ng/dL (241-827); TPO antibodies negative. MRI-Pituitary: Partial empty sella; infundibulum neurohypophysis normal; mild asymmetric enhancement (5.5 mm) left cavernous sinus. Treatment: Tab Hydrocortisone 25 mg/day, with complete clinical and biochemical response Suggestion of gonadotroph dysfunction and partial recovery of thyrotrope dysfunction/ injury. Hence, not on thyroxine replacement. Clinical Lessons: Mechanisms for differential cellular vulnerability for ICI induced autoimmune pathologies thyroid (destructive versus stimulatory), islet beta cells, adrenal cortical cells, various anterior pituitary cells (corticotrophs vs thyrotrophs and gonadotrophs need elucidation. Specific molecular and cellular immunopathogenic pathways in different autoimmune endocrinopathies appear distinct and disparate. Presentation: 6/2/2024
Shankar et al. (Tue,) studied this question.