Autoantibodies to the β1-Adrenoceptor from Patients with Periodontitis as a Risk Factor for Cardiac Dysfunction

The presence of serum autoantibodies in periodontitis (P) patients against β(1)-adrenoceptor (β(1)-AR), using cardiac membranes or a synthetic β(1)-AR peptide corresponding to the second extracellular loop of human β(1)-AR as antigens, permit us to detect circulating antibody from 40 P patients but not in 20 normal individuals (control). Simultaneously, the P patients exhibited a decrease in HRV. Anti-β(1)-AR IgG titters correlated with the decrease in HRV of the same patients and the anti-β(1)-AR peptide IgG displayed partial agonist-like activity and modified the contractility of isolated atria, produced cyclic nucleotides, and inhibited the β(1)-AR agonistic activity of isoproterenol. We demonstrated in this study an association between periodontitis infection and an increased risk of cardiac disease, thereby highlighting the role of anti-β(1)-AR autoantibodies in alteration of myocardial contractility.