Impaired myocyte function in vitro incubated with sera from patients with myocarditis

Abstract

Sera positive for antimyolemmal antibodies (AMLAs) from patients with acute biopsy-proven myocarditis exerted a cytotoxic effect on cardiocytes stimulated in vitro. Using an edge-detecting system, contraction amplitude and contraction velocity were altered after the addition of AMLA-positive sera when compared to sera from healthy controls. Antibodies alone did not change the functional parameters. Only the presence of complement and heart-reactive antibodies mediated the detrimental effects. This suggests that a complement-mediated antibody-dependent immune mechanism is operative in human myocarditis.