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, K. E., Cunningham, M. W., Lee, C. K., Ward, K., Tong, A., Danon, S., Simon, C., Delaney, J. W., Canter, C. E. Autoimmunity Against the Heart and Cardiac Myosin in Children With Myocarditis. Journal of cardiac failure 22, 520-528 (2016).