Defective antibody-mediated opsonisation of S. pneumoniae in high risk patients detected by flow cytometry

Immunol Lett. 1996 Jan;49(1-2):83-9. doi: 10.1016/0165-2478(95)02487-5.


Invasive pneumococcal infection continues to be a significant cause of morbidity and mortality especially in patients with antibody deficiencies and disorders affecting the reticulo-endothelial system. Current recommendations for prophylaxis in these patients include immunization with 23-valent pneumococcal polysaccharide capsular vaccines. Post-immunization responses are commonly assessed by measuring serum antibody levels. However, there is no defined protective antibody range and this approach fails to determine the functional capacity of the antibodies. A simple, reproducible flow cytometric method of assessing the antibody-mediated opsonic activity against S. pneumoniae is described. This assay detected defective opsonic function in post-immunized at-risk patients who developed invasive pneumococcal infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bacterial Vaccines / immunology
  • Bone Marrow Transplantation / immunology
  • Child
  • Child, Preschool
  • Colony Count, Microbial
  • Flow Cytometry
  • Humans
  • Leukocyte Count
  • Middle Aged
  • Observer Variation
  • Opsonin Proteins / blood*
  • Phagocytosis / immunology
  • Plasma / immunology
  • Plasma / microbiology
  • Pneumococcal Vaccines
  • Streptococcus pneumoniae / immunology*
  • Temperature
  • Time Factors


  • Bacterial Vaccines
  • Opsonin Proteins
  • Pneumococcal Vaccines