[Use of immunoenzyme analysis for determining the persistence and biodegradation of antigens in the cell wall of group A streptococci in patients with rheumatism].

A sandwich ELISA system was used for the study of the identification of antigenic group A polysaccharide determinants by antibodies in a suspension of streptococcus cells with varying degrees of lysis. Antibodies were able to identify less than 0.01% of antigenic A polysaccharides determinants in intact streptococcal cells. It is concluded that A polysaccharide is a marker of the destroyed group A streptococcus cells. The circulation of group A polysaccharide was examined in the sera of patients with rheumatism and acute streptococcal tonsillitis. Group A polysaccharide was detectable more frequently in rheumatic patients, as compared to those with tonsillitis, and circulated for long periods of time in the vascular network. Avidity and titres of antibodies to group A polysaccharide were determined in rheumatic patients with different degrees of antigenemia. In cases of marked antigenemia, correlation was disrupted between the titre and avidity of antibodies to group A polysaccharides.