Humoral immune response against contractile proteins (actin and myosin) during cardiovascular disease.

Sensitive and highly specific ELISA assays were developed to determine humoral immune response against actin and myosin in 122 patients suffering from various cardiovascular diseases: acute viral myocarditis (n = 10, MYO), acute myocardial infarction (n = 28, AMI), valve surgery (n = 35, VALVE), coronary bypass surgery (n = 35, CABG), and peripheral vascular surgery (n = 14, VASC). Anti-actin and anti-myosin antibodies were determined on admission and serially during a period of 90 days. Anti-actin and anti-myosin immune response (IgG, IgM) was expressed comparing absorbance of the patients' serum with a reference serum. In the different patient groups significantly (P less than 0.01) higher anti-actin and anti-myosin antibody concentrations were found on admission compared with age-matched control groups. During follow-up, all patient groups except the vascular surgery group showed a significant immune response against actin and myosin, with an immune response ratio (peak/admission) for AMA IgG and IgM respectively of 2.12 and 2.40 in the VALVE group, 1.30 and 1.99 in the CABG group, 1.42 and 1.48 in the AMI group and 1.66 and 1.25 in the MYO group; and for AAA IgG and IgM respectively of 1.57 and 3.00 in the VALVE group, 1.54 and 1.64 in the CABG group, 1.25 and 1.07 in the AMI group, and 1.42 and 1.42 in the MYO group. A significant correlation between pre-cardiac injury and peak post-cardiac injury anti-myosin and anti-actin autoantibody levels could be demonstrated suggesting that pre-injury sensitization to these antigens plays an important role in evoking post-cardiac injury immune response.(ABSTRACT TRUNCATED AT 250 WORDS)