title: Measurement of growth-inhibiting (bactericidal) antibodies in patients with meningococcal meningitis and in subjects immunized with meningococcal polysaccharide vaccine by a [3H]thymidine assay.
abstract: We measured bactericidal antibodies against meningococci by a method which depends on the inhibition of [3H]thymidine uptake by bacteria in the presence of antibody and complement. A significant increase in antibody activity was found in sera from patients who had recovered from group A meningococcal meningitis (mean inhibition, 38.9 +/- 4.4%) compared with antibody activity present in sera from patients in the acute phase (mean inhibition, 7.0 +/- 2.4%) (P less than 0.001). Similarly, a significant increase in inhibitory activity against group C meningococci was observed 2 weeks after immunization with group C polysaccharide. A close correlation was obtained between the results of the thymidine assay and of a standard colony-counting method and hemagglutination assay. The assay is readily applicable to testing large numbers of samples.
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis*; D001428:Bacterial Vaccines / Q000276:immunology*; D003165:Complement System Proteins / Q000378:metabolism; D006386:Hemagglutination Tests; D006801:Humans; D008585:Meningitis, Meningococcal / Q000276:immunology*; D022401:Meningococcal Vaccines; D009345:Neisseria meningitidis / Q000276:immunology* / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D013936:Thymidine / Q000378:metabolism; D014611:Vaccination
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D022401:Meningococcal Vaccines; D011135:Polysaccharides, Bacterial; C037676:meningococcal group C polysaccharide; D003165:Complement System Proteins; D013936:Thymidine