title: Anti-beta 1-adrenoreceptor autoantibodies and myocardial sympathetic nerve activity in chronic heart failure.
abstract: BACKGROUND
  The autoantibodies stimulate the beta1-adrenoreceptors on cardiac myocytes similar to norepinephrine, and are associated with reduced cardiac function. Iodine-123 metaiodobenzylguanidine ((123)I-MIBG) is metabolized similarly to norepinephrine. This study was undertaken to investigate the relationship between cardiac stimulation by anti-beta1-adrenoreceptor autoantibodies and myocardial sympathetic nervous activity in patients with chronic heart failure.
  
  
  METHODS
  We screened for the anti-beta1-adrenoreceptor autoantibodies in 52 patients with chronic heart failure by conducting an enzyme-linked immunosorbent assay, and underwent (123)I-MIBG scintigraphy in 27 of the patients. Anterior planar images of (123)I-MIBG were obtained 15 min and 3 h after the injection. We determined the heart to mediastinum radioactivity ratio (H/M), and calculated the rate of washout of (123)I-MIBG from the heart.
  
  
  RESULTS
  Patients with New York Heart Association functional class III or IV had higher levels of anti-beta1-adrenoreceptor autoantibodies than those with class I or II (p<0.01). The autoantibody level was significantly correlated with delayed H/M (r=-0.65, p<0.001) and washout rate (r=0.65, p<0.001). Sixteen patients with a cardiac event showed higher levels of the autoantibodies (p<0.05). Cardiac event-free survival was poorer in patients with the autoantibody levels >10 U/ml than that <10 U/ml (log-rank=12.1, p<0.001).
  
  
  CONCLUSIONS
  The anti-beta1-adrenoreceptor autoantibodies are closely associated with cardiac sympathetic nervous activity assessed by (123)I-MIBG and cardiac event in patients with chronic heart failure.
authors.affiliation: Division of Cardiovascular Medicine, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Aso
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yazaki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kasai
authors.forename: Masafumi
authors.initials: M
authors.lastname: Takahashi
authors.forename: Taku
authors.initials: T
authors.lastname: Yoshio
authors.forename: Keiji
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Uichi
authors.initials: U
authors.lastname: Ikeda
mesh_terms: D000368:Aged; D001323:Autoantibodies / Q000096:biosynthesis*; D002908:Chronic Disease; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D011877:Radionuclide Imaging; D018342:Receptors, Adrenergic, beta-1 / Q000276:immunology* / Q000378:metabolism; D017779:Sympathetic Fibers, Postganglionic / Q000378:metabolism*
chemical_list: D001323:Autoantibodies; D018342:Receptors, Adrenergic, beta-1