Autoimmune Hypertensive Syndrome

Intravenous infusion of epinephrine or norepinephrine produces hypertension and symptoms similar to a pheochromocytoma.1,2 The sequelae are predictable on the basis of continuous infusion of agonists that activate β and α adrenergic receptors (ARs). These monoamine agonists, however, are not the only means by which β-ARs can be activated. Activating autoantibodies (AAs) directed toward the β1AR and/or the β2AR have been demonstrated in some patients with idiopathic dilated cardiomyopathy,3–5 Chagas ’ disease,6,7 and other forms of cardiomyopathy.8,9 Several studies have demonstrated that these antibodies possess the ability to activate the intrinsic βAR signal transduction system; however, these studies have focused only on the possible relationship of the AAβAR agonist effects on cardiomyopathy. Because β-agonist excess also produces changes in systemic blood pressure, one would expect the presence of AAβAR to produce a phenotype including some features observed in patients with an epinephrine-only secretory neuroendocrine tumor. Isolated studies have reported the concurrence of activating autoantibodies to the α1AR10,11 or to the angiotensin receptor (AT1)12,13 in a few patients with associated hypertension. Herein, we present a hypertensive patient with no clinical evidence for a pheochromocytoma