[Various aspects of humoral immunity in meningococcal infections. II. Formation of antibodies to group A meningococci in adults with generalized meningococcal infections].

Altogether 258 serum samples obtained from 102 patients with generalized meningococcal infection were studied by means of the immune bacteriolysis test and the indirect hemagglutination test. This study revealed a pronounced increase in the titer of bactericidal and hemagglutinating antibodies to group A meningococcus in the process of the disease. The dynamics and intensity of antibody formation, revealed by means of the two tests, were found to be in complete correspondence. Antibody formation was most intensive in meningitis accompanied by meningococcemia. In most cases these antibodies were found to belong to the class of IgM on account of their physico-chemical nature. The highest bactericidal activity was found in the sera with high hemagglutinin titers; the summary titers of these sera were 4-64 times higher than the titers of cystein-resistant antibodies.