Beta 1-adrenergic receptor autoantibody (β1-AR autoantibody)

Beta 1-adrenergic receptor autoantibodies are immunoglobulin G (IgG) autoantibodies that recognize and bind the second extracellular loop of the heart’s β1-adrenergic receptor, a G protein-coupled receptor responsible for mediating cardiac inotropic and chronotropic responses to epinephrine and norepinephrine[1][2][3][4][5][6]. These autoantibodies can act as receptor agonists or antagonists, desensitizing the receptor, promoting sustained intracellular calcium influx, inducing cardiomyocyte apoptosis, and contributing to the development and progression of dilated cardiomyopathy, arrhythmias, heart failure, and other diseases. Their presence can predict disease risk and outcomes, and their pathogenic activity may be mitigated by targeted immunoadsorption or β-blocker therapy, with response varying by antibody subclass (notably IgG3)[3][6].

Other names

Beta-1 adrenergic receptor autoantibodyβ1ARAbβ1AR-AAbAnti-β1-adrenergic receptor antibodyAnti-β1AR Abβ1-adrenergic receptor antibody

β-blockers antagonize receptor activation by catecholamines and can modify the signaling bias induced by the autoantibodies, improving heart function in β1ARAb-positive patients. Immunoadsorption removes pathogenic autoantibodies, improving cardiac function in affected individuals. Autoantibodies may have agonist-like, antagonist-like, or biased-modulatory effects at the receptor, depending on IgG subclass.