Antimyocardial Serum Factors in Rheumatic Fever Detected by the Immunofluorescence Method

Antimyocardial serum factors were examined by means of the indirect immunofluorescence method, with special regard to rheumatic fever and rheumatic carditis, using human (adult, neonatal and embryonal) as well as rabbit heart tissue sections as substrates. In the group of 74 patients with a rheumatic fever attack, positive sarcolemmal-subsarcolemmal reaction was observed, in 43.24 % cases, associated occasionally with intermyofibrillar reaction; prevailing incidence was found in patients with active carditis, preexisting valvular disease and in patients with a greater number of repeated attacks. The authors failed to determine the relation between antimyocardial factors on the one side and the titer of streptococcal antibodies (ASO, ASH) as well as indices of humoral activity on the other side. A suppression of antimyocardial immunofluorescence reaction was observed in some cases of treatment with high doses of glucocorticoids. The incidence of antimyocardial serum factors also in other rheumatic and collagen diseases, especially in systemic lupus erythematosus and rheumatoid arthritis, was less frequently recorded. Antimyocardial serum factors (anti-sarcolemmal-subsarcolemmal) can be considered as immunoglobulins reacting not only with homologous, but also with heterologous antigenic material and due to their frequent occurrence characteristic, but not specific, for rheumatic fever. Their biological function considered on the basis of the present knowledge in the discussion, has not been definitely explained so far.