Natural and lectin-dependent cytotoxicity in virus-induced human myocarditis.

The human spontaneous cell-mediated cytotoxicity (SCMC) and lectin dependent cell-mediated cytotoxicity (LDCMC) of peripheral blood leukocytes (PBL) were studied in patients with different forms of postviral myocarditis. The PBL cytotoxicity was evaluated using 51Cr-labelled CRBC (chicken red blood cells) as targets and results were expressed as a percentage of specific release. The control group was represented by 150 healthy persons of both sexes. No significant age-related differences were found in SCMC and LDCMC activities of PBL from healthy persons. Myocarditis was diagnosed according to clinical criteria. All investigated myocarditis patients suffered from Coxsackie B or Echo-virus infections which were confirmed using virus neutralizing antibody test and haemagglutination inhibition test, respectively. The increase in the investigated cytotoxic cell activity in acute and exacerbated myocarditis and its normalization in chronic one may directly suggest the participation of these cells in heart injury.