Anti-GPCR Autoantibodies: The Autoimmune Vascular Engine of ME/CFS

1. The Charité Berlin Discoveries (Scheibenbogen et al.)

Led by Professor Carmen Scheibenbogen at the Charité Institute of Medical Immunology (PMID: 26999398), researchers screened plasma from ME/CFS cohorts against human autonomic receptors.

They identified that a substantial subset (30% to 40%) of patients possess elevated functional autoantibodies targeting:

• β2-Adrenergic Receptors: Regulate vasodilation in peripheral skeletal muscle beds. Autoantibody binding interferes with muscular hyperemia during exertion.
• β1-Adrenergic Receptors: Regulate cardiac pacemaker firing and inotropy. Positive titers correlate directly with resting tachycardia and palpitations.
• M3 & M4 Muscarinic Receptors: Mediate cholinergic parasympathetic vasodilation and enteric motility. Antibodies cause paradoxical vasoconstriction and gastroparesis.

2. Proof of Causality: Immunoadsorption Clinical Trials

To prove that these autoantibodies are pathogenic rather than harmless bystanders, the Charité team performed Immunoadsorption (IA)—an apheresis procedure that selectively filters IgG antibodies from the bloodstream over 5 consecutive days (PMID: 29559384).

Following immunoadsorption, circulating anti-β2 and anti-M3 autoantibodies dropped rapidly, resulting in rapid improvements in cerebral blood flow, reduction in PEM severity, and restoration of endothelial function.