title: Serum opsonins to group B meningococci.
abstract: The production of serum opsonins and other antibodies to serogroup B serotype 15 meningococci was examined in 7 patients with serogroup B serotype 15 meningococcal disease and 7 volunteers immunized with a vaccine containing outer membrane proteins from serogroup B serotype 2b and 15 meningococcal strains complexed with polysaccharides from serogroups A, C, Y and W-135 meningococci. Serum opsonic activity was measured by a flow cytometric phagocytosis technique, using unfixed serogroup B Neisseria meningitidis labelled with fluorescein isothiocyanate. Serum antibodies to outer membrane complexes prepared from the meningococcal test strain, B:15:P1.16, were measured by an enzyme linked immunosorbent assay. The mean number of bacteria per phagocyte increased from 9.7 to 17.3 (mean difference 7.6, p less than 0.001) when the meningococci were opsonized with convalescent sera compared to sera obtained during the acute illness, and from 8.0 to 15.4 (mean difference 7.4, p less than 0.001) when opsonized with sera from immunized versus pre-immunized volunteers. The patients had insignificant amounts of serum antibodies to the group B meningococcal test strain on admission to hospital. Two weeks later all had a marked increase in IgG, IgM and IgA serum antibodies. Vaccination caused a marked increase in serum IgG antibodies. Serum opsonic activity and IgG levels were still high 6 weeks after the acute illness/immunization. A correlation was observed between serum opsonic activity and IgG antibody levels (r = 0.883, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001428:Bacterial Vaccines / Q000494:pharmacology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D008297:Male; D008589:Meningococcal Infections / Q000276:immunology / Q000517:prevention & control; D009345:Neisseria meningitidis / Q000145:classification / Q000276:immunology*; D009895:Opsonin Proteins / Q000096:biosynthesis*; D010587:Phagocytosis
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D009895:Opsonin Proteins