Autoantibodies against M2-muscarinic acetylcholine receptors: new upstream targets in atrial fibrillation in patients with dilated cardiomyopathy.

Abstract

AIM:

To characterise the clinical significance of M2-muscarinic acetylcholine receptor autoantibodies (M2-AAB) in patients with dilated cardiomyopathy (DCM).

METHODS AND RESULTS:

Sera from 104 patients with DCM, age-matched with 104 patients with idiopathic atrial fibrillation (Af) and 104 healthy control subjects, were screened for M2-AAB by enzyme-linked immunosorbent assay (ELISA). IgG purified by Protein-A column was also used as a primary antibody in ELISA. In DCM, M2-AAB were detected in 40% of patients using whole sera and in 36% of patients using purified IgG. M2-AAB were also found in several patients with idiopathic Af (23%, 23%), and these frequencies were significantly higher than those in healthy subjects (8%, 8%). Af was more common in AAB-positive than in AAB-negative patients with DCM. Multivariable analysis confirmed that M2-AAB were independent predictors of the presence of Af in such patients. We determined electrophysiological changes by adding patient purified M2-AAB to chick embryos. Purified IgG from both Af and DCM patients exhibited negative chronotropic effects and induced supraventricular arrhythmias.

CONCLUSION:

M2-AAB may play a role in mediating the development of Af in patients with DCM.

• Authors: Akiyasu Baba, Tsutomu Yoshikawa, Yukiko Fukuda, Takashi Sugiyama, Megumi Shimada, Makoto Akaishi, Kanji Tsuchimoto, Satoshi Ogawa, Michael Fu
• Journal: European heart journal (Eur Heart J) Vol. 25 Issue 13 Pg. 1108-15 (Jul 2004) ISSN: 0195-668X [Print] England
• PMID: 15231368 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Autoantibodies
• Immunoglobulin G
• Receptor, Muscarinic M2

Topics

• Atrial Fibrillation (immunology)
• Autoantibodies (analysis)
• Cardiomyopathy, Dilated (complications, immunology)
• Enzyme-Linked Immunosorbent Assay
• Female
• Humans
• Immunoglobulin G (analysis)
• Male
• Middle Aged
• Receptor, Muscarinic M2 (immunology)