Patients with dilated cardiomyopathy had a higher prevalence of autoantibodies against beta 1 adrenoceptors (32% vs 9%) and M2 muscarinic receptors (36% vs 13%) compared to healthy subjects.
Case-Control (n=50)
Do patients with dilated cardiomyopathy have a higher prevalence of autoantibodies against specific G-protein-coupled cardiovascular receptors compared to healthy subjects?
A subgroup of patients with dilated cardiomyopathy possesses a specific spectrum of autoantibodies directed against beta 1 adrenoceptors and M2 muscarinic receptors.
Absolute Event Rate: 32% vs 9%
In order further to identify the prevalence of anti-receptor autoantibodies in the sera of patients with dilated cardiomyopathy (DCM), we attempted to detect autoantibodies against a series of G-protein-coupled cardiovascular receptors in a well-defined population of DCM patients from Japan. Peptides corresponding to the sequences of the second extracellular loops of the human beta 1 and beta 2 adrenoceptors, alpha 1 adrenoceptors, M2 muscarinic acetylcholine receptors and angiotensin II-1 (AT1) receptors were used as antigens in an enzyme immunoassay to screen the sera from patients with DCM (n = 28). Nine sera from patients with DCM (32%) and 2 sera from healthy subjects (9%) recognized the beta 1 adrenoceptor peptide. Ten sera from patients (36%) and 3 sera from healthy subjects (13%) recognized the M2 receptor peptide. Thirty-six per cent of the patients with autoantibody against the beta 1 adrenoceptor peptide. Ten sera from patients (36%) and 3 sera from healthy subjects (13%) recognized the M2 receptor peptide. Thirty-six per cent of the patients with autoantibody against the beta 1 adrenoceptor had autoantibody against the M2 receptor. However, no significantly high frequencies of autoantibodies against the beta 2 adrenoceptor, alpha 1 adrenoceptor and AT1 receptor were found in DCM patients. Our results demonstrate that a subgroup of patients with DCM have a specific spectrum of autoantibodies which are specifically directed against the second extracellular loops of the beta 1 adrenoceptors and M2 muscarinic receptors rather than other cardiovascular receptors.
Matsui et al. (Sun,) conducted a case-control in Dilated cardiomyopathy (n=50). Enzyme immunoassay for autoantibodies against G-protein-coupled cardiovascular receptors vs. Healthy subjects was evaluated on Prevalence of autoantibodies against the beta 1 adrenoceptor peptide. Patients with dilated cardiomyopathy had a higher prevalence of autoantibodies against beta 1 adrenoceptors (32% vs 9%) and M2 muscarinic receptors (36% vs 13%) compared to healthy subjects.