Introduction:Checkpoint inhibitors have significantly improved the prognosis of patients with advanced melanoma. These cancer immunotherapy drugs have specific endocrine autoimmune toxicity. We describe a case of an adrenal insufficiency secondary to pembrolizumab, an anti-programmed cell death-1 monoclonal antibody. Moreover, this case of polyendocrinopathy resulting from a pembrolizumab as the adrenal insufficiency occurred after a thyroiditis.Participant:A 55-year-old female was started on pembrolizumab immunotherapy for a metastatic choroidal melanoma. Five months after initiation, she suffered from thyrotoxicosis. A thyroiditis was diagnosed by iodine-123 thyroid scintigraphy and ultrasonography. Pembrolizumab therapy was maintained. Two weeks later, without any other treatment given, she patient developed hypothyroidism and levothyroxine substitution was started. Pembrolizumab proved to be ineffective and was stopped 9 months after initiation. One month following its discontinuation, the patient was hospitalized in the intensive care unit. Severe hyponatremia (115 mmol/L) associated with hyperkalemia (5.7 mmol/L) led to the early recognition and treatment of an acute adrenal insufficiency. Positive results for adrenal cortex and 21-hydroxylase antibodies were in favor of autoimmune toxicity.Conclusion:This case highlights the diversity of potential endocrine toxicity of checkpoint inhibitors. Because acute adrenal crisis may be associated with substantial morbidity and mortality, physicians must be aware of these rare adverse events to allow an early diagnosis.

P atients with primary aldosteronism (PA) have either bilateral (idiopathic hyperplasia) or unilateral (aldosterone-producing adenoma or unilateral hyperplasia) adrenal disease. 1,2 Localizing the source of excessive aldosterone secretion is critical to select the appropriate therapy. Unilateral PA can be treated by laparoscopic adrenalectomy, which normalizes serum potassium concentrations in almost all cases and cures or improves hypertension in >80% of patients.3,4 By contrast, medical management with mineralocorticoid receptor antagonists is recommended as the first-line treatment in bilateral PA. 5Adrenal vein sampling (AVS) is currently considered the gold standard to differentiate unilateral from bilateral aldosterone hypersecretion and is recommended in almost all patients with PA who are eligible for surgical management. 5,6 The accuracy of catheter placement in the adrenal veins can be verified from the cortisol concentration in the adrenal veins divided by that in the inferior vena cava or a peripheral vein (selectivity index [SI]). If the SI reaches the predefined cut-off, the lateralization index (LI) is then used to classify PA into unilateral or bilateral disease. The LI is defined as the highest aldosterone/ cortisol concentration ratio (dominant adrenal vein) divided by the lowest aldosterone/cortisol concentration ratio (nondominant adrenal vein). Some investigators also propose the use of the contralateral suppression index, defined by the aldosterone/ cortisol concentration ratio of the nondominant adrenal vein divided by the peripheral aldosterone/cortisol concentration ratio.7 However, the protocol of AVS (simultaneous or sequential bilateral AVS, use of cosyntropin or not, and the protocol of cosyntropin infusion) and the SI and LI cut-offs used to interpret the results are not currently standardized. 7-9We have interpreted a large number of AVS procedures with criteria used in 4 reference centers or proposed by a recent consensus statement. 6,[10][11][12] The first objective of this study was to examine to which extent the interpretation of AVS may differ according to the criteria used for its interpretation. The second goal was to assess the reproducibility of this interpretation when multiple blood samples were drawn from the same adrenal vein. Methods PatientsThis retrospective study included all patients who underwent AVS in our hypertension referral center between January 2001 and July Abstract-Guidelines promote the use of adrenal vein sampling (AVS) to document lateralized aldosterone hypersecretion in primary aldosteronism. However, there are large discrepancies between institutions in the criteria used to interpret its results. This study evaluates the consequences of these differences on the classification and management of patients. The results of all 537 AVS procedures performed between January 2001 and July 2010 in our institution were interpreted with 4 diagnostic criteria used in experienced institutions where AVS is performed without cosyntropin (Brisbane, Padua, Paris, an...