Crossed immunoelectrophoretic analysis of Neisseria meningitidis antigens and of corresponding antibodies in patients with meningococcal disease.

Sixty-three different antigens of Neisseria meningitidis groups A, B and C were demonstrated by means of crossed immunoelectrophoresis against rabbit antiserum. The group-specific polysaccharides A and C were identified in the immunoprecipitate pattern. The majority of the remaining antigens were common to all three groups of meningococci. A clearcut rise in antibodies was found in all of 27 patients with meningococcal meningitis or septicaemia. These antibodies were directed against both group-specific antigens and common antigens. No such rise was seen among the 22 patients with purulent meningitis of non-meningococcal etiology. Altogether 15 precipitins were detected in the patients with meningococcal disease. Nine of these antibodies could be identified by comparison with the rabbit antiserum. The antibody rise was semiquantified by means of a scoring system. The rise in the precipitin score of antibodies against common antigens in patients infected with group B meningococci was significantly higher than in patients infected with group A meningococci.