title: Autoimmunity Against the Heart and Cardiac Myosin in Children With Myocarditis.
abstract: BACKGROUND
  Host autoimmune activity in myocarditis has been proposed to play a role in development of cardiac disease, but evidence of autoimmunity and relationship to outcomes have not been evaluated in pediatric myocarditis.
  
  
  METHODS
  We performed a multi-institutional study of children with clinical myocarditis. Newly diagnosed patients were followed for up to 12 months and previously diagnosed patients at a single follow-up for serum levels of autoantibodies to human cardiac myosin, beta-adrenergic receptors 1 and 2, muscarinic-2 receptors, and antibody-mediated protein kinase A (PKA) activation in heart cells in culture. Results were compared with those of healthy control children.
  
  
  RESULTS
  Both previously diagnosed patient at follow-up (P = .0061) and newly diagnosed patients at presentation (P = .0127) had elevated cardiac myosin antibodies compared with control subjects. Antibody levels were not associated with recovery status at follow-up in either group. PKA activation was higher at presentation in the newly diagnosed patients who did not recovery normal function (P = .042).
  
  
  CONCLUSIONS
  Children with myocarditis have evidence of autoantibodies against human cardiac myosin at diagnosis and follow-up compared with control subjects. Differences in antibody-mediated cell signaling may contribute to differences in patient outcomes, as suggested by elevated antibody-mediated PKA activation in heart cells by the serum from nonrecovered patients.
authors.affiliation: Washington University School of Medicine in St Louis, St Louis, Missouri. Electronic address: simpson_k@kids.wustl.edu.
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Simpson
authors.affiliation: University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Madeleine W
authors.initials: MW
authors.lastname: Cunningham
authors.affiliation: Washington University School of Medicine in St Louis, St Louis, Missouri.
authors.forename: Caroline K
authors.initials: CK
authors.lastname: Lee
authors.affiliation: University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Kent
authors.initials: K
authors.lastname: Ward
authors.affiliation: Pediatrix Cardiology, Springfield, Missouri.
authors.forename: Alan
authors.initials: A
authors.lastname: Tong
authors.affiliation: Saint Louis University School of Medicine, St Louis, Missouri.
authors.forename: Saar
authors.initials: S
authors.lastname: Danon
authors.affiliation: University of Missouri Kansas City School of Medicine, Kansas City, Missouri.
authors.forename: Catherine
authors.initials: C
authors.lastname: Simon
authors.affiliation: University of Nebraska Medical Center, Omaha, Nebraska.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Delaney
authors.affiliation: Washington University School of Medicine in St Louis, St Louis, Missouri.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Canter
mesh_terms: D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D015551:Autoimmunity; D024722:Cardiac Myosins / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D017868:Cyclic AMP-Dependent Protein Kinases / Q000032:analysis / Q000276:immunology*; D006321:Heart / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007223:Infant; D009205:Myocarditis / Q000097:blood / Q000000981:diagnostic imaging / Q000276:immunology*; D032383:Myocytes, Cardiac / Q000737:chemistry / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D017868:Cyclic AMP-Dependent Protein Kinases; D024722:Cardiac Myosins
keywords: Myocarditis; autoantibody; autoimmunity