Immune reactions in tuberculous and chronic constrictive pericarditis. Clinical data and diagnostic significance of antimyocardial antibodies.

Humoral immune reactions were analyzed in 12 patients with exudative tuberculous pericarditis, 10 patients with constrictive pericarditis due to former tuberculosis, 10 patients with viral pericarditis, 20 patients with pulmonary tuberculosis, and 98 healthy donors. Pericarditis occurred in 12.5% of the patients with tuberculosis, whereas the incidence of tuberculosis in the 149 patients with pericarditis was 8%. Repeated pericardial puncture and pericardial effusions of greater than 500 ml with impending cardiac tamponade had to be performed in 4 patients. Clinical data indicated probable myocardial involvement in 4 of 12 patients. Antimyolemmal antibodies, which are a muscle-specific subtype of antisarcolemmal antibodies, were found in all patients with exudative tuberculous pericarditis and viral perimyocarditis, in only 1 of 12 patients with constrictive pericarditis, and in no patients with pulmonary tuberculosis. Antifibrillary antibodies--primarily of the antimyosin type--were missed in patients with viral heart disease but were demonstrated in 75% of patients with tuberculous pericarditis. Only sera with complement-fixing antimyolemmal antibodies of the IgG type in titers greater than 1:40 induced cytolysis of vital adult heterologous cardiocytes isolated and enriched by silica sol gradient centrifugation. These findings suggest not only that antimyolemmal antibodies are diagnostic indicators of perimyocardial involvement in tuberculous pericarditis, but also that they may play a significant role in its pathogenesis.