title: Ex vivo bactericidal activity against group C Neisseria meningitidis in seronegative subjects.
abstract: BACKGROUND
  To determine the anti-meningococcal C immunological activity by adding functional tests (opsonophagocytosis) to the classical serology techniques.
  
  
  METHODS
  42 adult volunteers were screened using serological methods (determination of total and bactericidal antibodies). Seronegative subjects were tested by opsonophagocytosis.
  
  
  RESULTS
  24 subjects (57%) showed serological evidence of previous contact with Neisseria meningitidis group C antigens: 19 subjects had both total and bactericidal antibodies, two subjects had only total antibodies and three subjects had only bactericidal antibodies. Of the 18 seronegative subjects, five showed ex vivo activity in killing curves with or without polymorphonuclear cells: two subjects exhibited only complement-mediated bactericidal activity, one subject only opsonophagocytosis, and two subjects exhibited both activities.
  
  
  CONCLUSIONS
  The addition of functional tests to the classical serological determination increases the evidence of previous contact with N. meningitidis antigens by 12%.
authors.affiliation: Microbiology Dept., School of Medicine, University Complutense, Madrid, Spain.
authors.forename: M L
authors.initials: ML
authors.lastname: Gómez-Lus
authors.forename: L
authors.initials: L
authors.lastname: Aguilar
authors.forename: J
authors.initials: J
authors.lastname: Vázquez
authors.forename: M J
authors.initials: MJ
authors.lastname: Giménez
authors.forename: G
authors.initials: G
authors.lastname: Ruiz
authors.forename: S
authors.initials: S
authors.lastname: Berrón
authors.forename: F
authors.initials: F
authors.lastname: Fuentes
authors.forename: J
authors.initials: J
authors.lastname: Prieto
mesh_terms: D000328:Adult; D000906:Antibodies / Q000097:blood; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology; D001770:Blood Bactericidal Activity; D003165:Complement System Proteins / Q000276:immunology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008589:Meningococcal Infections / Q000097:blood*; D009345:Neisseria meningitidis / Q000276:immunology*; D009895:Opsonin Proteins
chemical_list: D000906:Antibodies; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D009895:Opsonin Proteins; D003165:Complement System Proteins