ABSTRACT
Objective: To study the relationship between autoantibodies to myocardium β1-adrenergic receptor (β1-receptor), M2-muscarinic receptor (M2-receptor) and hypertrophic cardiomyopathy (HCM) in relevant patients. Methods: Our research included in 2 groups: HCM group, n=81 patients and Control group, n=50 normal subjects. Synthetic peptides corresponding to amino acid sequence of second extracellular loops of β1-receptor and M2-receptor were used as antigens, ELISA was conducted to detect serum autoantibodies to β1-receptor and M2-receptor in both groups. Results: ① Compared with Control group, HCM group had the higher positive rates of autoantibodies as for β1-receptor was 58.02% (47/81) vs 12.00% (6/50) and for M2-receptor was 44.44 % (36/81) vs 10.00% (5/50), both P<0.05. ② Compared with Control group, HCM group had the higher mean geometric titers of autoantibodies as for β1-receptor was 1:85 vs 1:36 and for M2-receptor was 1:80 vs 1:35, both P<0.05. ③ In HCM group, 43.48 % patients with positive autoantibody to β1-receptor meanwhile have autoantibody to M2-receptor. Conclusion: HCM patients having both autoantibodies to β1-receptor and M2-receptor might be related to cardiac structure change and diastolic function decreasing. Both positive antibodies implies that immunological mechanism has been involved in pathophysiological process in HCM patients.