Assessment of antibody mediated cytolysis of adult cardiocytes isolated by centrifugation in a continuous gradient of Percoll in patients with acute myocarditis.

Principal objections to conventional cytotoxicity assays in cardiac disease with myocytes as target cells are the use of fetal or neonatal myocardium, the cell-membrane of which does not express all antigenic determinants, and the use of trypsin as enzyme for isolation of the cells, since this alters the myolemmal membrane considerably. An improved and rapid procedure for the isolation of intact adult cardiocytes with collaggenase was developed. by means of a performed continuous self-generating silica sol and gradient centrifugation average enrichment of 81% vital myocytes was achieved by a single isopycnic procedure. The yield was improved to 94 +/- 3% vital cells by identical second centrifugation. Cardiocytes isolated by this method were used as target cells in an assay measuring the cytolytic activity of antibodies in the presence of complement: sera of patients suffering from acute viral myocarditis (Coxsackie B- and influenza-virus) with complement fixing antisacrolemmal antibodies (ASA) of the IgG- and IgM-type showed significant cardiocytolysis. ASA are postulated to play a role in the pathogenesis of acute Coxsackie B- and influenza-virus myocarditis.