Autoimmunity Against the Heart and Cardiac Myosin in Children With Myocarditis.
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.
Journal of cardiac failure
Autoantibodies; Autoimmunity; Cardiac Myosins; Child; Child, Preschool; Cyclic AMP-Dependent Protein Kinases; Heart; Humans; Infant; Myocarditis; Myocytes, Cardiac
Myocarditis; autoantibody; autoimmunity
Simpson KE, Cunningham MW, Lee CK, et al. Autoimmunity Against the Heart and Cardiac Myosin in Children With Myocarditis. J Card Fail. 2016;22(7):520-528. doi:10.1016/j.cardfail.2016.02.009