Endocrine Abstracts

Introduction: The introduction of immunotherapy with checkpoint inhibitors for oncologic diseases has improved the survival and quality of life of our patients; however, these therapies are frequently associated with autoimmune endocrine disease.

Methods: Revision of the patient’s clinical record and the related literature.

Results: Clinical Case : An 88-year old woman was referred to our Endocrinology Clinic because of a PET image suggestive of bilateral adrenitis. Her history included essential hypertension and dyslipidaemia, treated only with enalapril 20 mg and atorvastatin 20 mg daily. She had been diagnosed in 2015 of melanoma with primary lesion in the right foot and extensive systemic metastases. She was treated with stereotactic body radiation therapy (I-SRBT) and conventional chemotherapy, plus eight cycles of pembrolizumab. Afterwards her melanoma was in complete remission, and the patient was asymptomatic except for asthenia and right malleolar oedema. A control PET was performed, showing bilaterally enlarged non-nodular adrenals (SUVmax 4.1 right adrenal, 5.8 left), suggesting bilateral adrenitis elicited by immunotherapy. Lab tests showed normal adrenal axis function, with glomerular filtration rate (CKD-EPI) 52 ml/min 1.73 m², Na⁺ 142 mEq/l, K⁺ 5.5 mEq/l, cholesterol 211 mg/dl, triglycerides 113 mg/dl, ACTH 12.6 pg/ml, cortisol basal 17.3 µg/dl. At this point she was referred to our Endocrinology Clinic. The presumptive diagnosis was bilateral adrenitis attributable to immunotherapy, without clear clinical or analytical manifestations. We ordered new lab tests. 2 months later the patient had very low fasting plasma cortisol (2.90 mg/ml) and aldosterone (3.7 ng/dl) with normal plasma ions, but her asthenia had improved, and she remained without treatment. A new lab control 2 months afterwards showed full recovery of her adrenal function (aldosterone 31.5 ng/dL, test ACTH → cortisol: 19.6, 25,10 and 24.7 mg/dl at 0’, 30’ and 60’, while a new PET scan showed lower adrenal activity (SUVmax 2.74 left, 2.24 right).

Conclusions: The new checkpoint inhibitors such as pembrolizumab unleash an autoimmune aggression against the neoplastic cells, but collateral damage is frequent and autoimmune disease affecting the thyroid, the adrenal glands, the hypophysis and/or the endocrine pancreas is a common occurrence. The peculiarity in our patient was that there was evidence of drug-induced adrenitis before the biochemical and clinical manifestations were apparent.