Anti-β-adrenoceptors autoimmunity causing 'idiopathic' arrhythmias and cardiomyopathy

Item Type:	Article
Title:	Anti-β-adrenoceptors autoimmunity causing 'idiopathic' arrhythmias and cardiomyopathy
Creators Name:	Brisinda, D. and Sorbo, A.R. and Venuti, A. and Ruggieri, M.P. and Manna, R. and Fenici, P. and Wallukat, G. and Hoebeke, J. and Frustaci, A. and Fenici, R.
Abstract:	Background: To determine the prevalence of anti-beta-adrenoceptors autoantibodies (a{beta}AA) in patients with idiopathic arrhythmias (IA) and to assess whether a{beta}AA are predictive markers for concealed cardiomyopathy in such patients. Methods and Results: Sixty-seven patients (group 1) with IA [25 supraventricular (SVA) and 42 ventricular (VA)]; 14 patients (group 2) with suspected cardiomyopathy, 12 patients with definite cardiomyopathy (group 3); and 19 healthy controls (group 4) were tested with an enzyme immunoassay, using synthetic peptides corresponding to the second extracellular loop of the human {beta}1- and {beta}2-adrenoceptors. Endomyocardial biopsy was performed in 29 patients. As compared with group 4 [3/19 (15.7%)], anti-{beta}1-adrenoceptor autoantibodies (a{beta}1AA) were more frequent in group-1 patients [38/67 (56.7%; P<0.01): 27/42 (64.2%; P<0.001) with VA and 11/25 (44%; P<0.05) with SVA]. 3 of the group 1 patients also had anti-{beta}2-adrenoceptor autoantibodies (aβ2AA). 4 were positive for a{beta}2AA only. Biopsy performed in 11/67 group 1 patients was abnormal in all. Of them, 7/8 (87.5%) with VA and 3/3 (100%) with SVA were positive for a{beta}1AA. PCR analysis from paraffin blocks of the 11 group 1 biopsied patients was negative for EV, EBV, HCV, AV, PVB19, INF A/B,HSV1/2, HHV6 and HHV8 viral genomes. Conclusions: The second extracellular loop of the {beta}-adrenoceptor is the molecular target of specific autoantibodies. Positivity for a{beta}1AA predicts abnormal histological findings in 90% of IA patients and suggests that autoimmunity might play an arrhythmogenic role.
Keywords:	Arrhythmia, beta-Adrenoceptors, Biopsy, Cardiomyopathy, Myocarditis
Source:	Circulation Journal
ISSN:	1346-9843
Publisher:	Japanese Circulation Society
Volume:	76
Number:	6
Page Range:	1345-1353
Date:	25 May 2012
Official Publication:	https://doi.org/10.1253/circj.CJ-11-1374
PubMed:	View item in PubMed

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