Figure 1. Levels of circulating β1AR-Aabs and M5R-Aabs of patients (before therapy) and controls. Left and Right: Serum levels of β1AR-Aabs and M5R-Aabs were measured by IgG-binding to the respective native receptors (CellTrend GmbH). Middle: β1AR-Aabs were determined by IgG-binding to a cyclic peptide providing a valid representation of the presumed pathogenic conformational auto-epitope within the second extracellular loop of the receptor associated with the active receptor conformation (indicated CP). ***: differences at p < 0.001 significance.