[Detection of an antigen of the L-forms of group A hemolytic streptococci in the sera of rheumatic patients following immune complex separation].

Tests were carried out to confirm the presence of the antigens of group A hemolytic streptococci in the L-form as a part of immune antigen-antibody complexes in the blood of rheumatic patients. The preliminary dissociation of antigen-antibody complexes with the subsequent gel filtration of the samples resulted in a significant increase in the number of serum samples giving the positive result in the aggregate hemagglutination test. The total number of serum samples yielding the antigen was more than 69.4%, whereas the commonly used aggregate hemolysis test allowed detection of the L-form antigen in 18-24% of serum samples obtained from rheumatic patients, as well as from patients with infectious myocarditis.