title: Response to Pneumococcal Polysaccharide Vaccination in HIV-Positive Individuals on Long Term Highly Active Antiretroviral Therapy.
abstract: OBJECTIVE
  Streptococcus pneumoniaecontinues to cause serious infections in HIV-positive individuals in the era of highly active anti-retroviral therapy. This led to the recommendation to revaccinate HIV-positive individuals with PPV23 five years after primary vaccination. The benefits of revaccination and the impact of long term highly active anti-retroviral therapy (HAART) on antigen-specific B cell reconstitution have remained unclear thus far and were investigated.
  
  
  METHODS
  We assessed antibody levels, opsonophagocytic activity and phenotype of pneumococcal polysaccharide (PPS) specific-B cells post-revaccination in long term HAART cohorts stratified according to CD4 count as group A (CD4>200) and group B (CD4<200). Anti-PPS IgG, IgM and functional antibody response against vaccine serotypes 14 and 23F were measured by ELISA and opsonophagocytic assay followed by phenotypic analysis of PPS14 and 23F-specific B cells using fluorescently labeled PPS.
  
  
  RESULTS
  Significant increases in total and functional antibody titers were noted in groups A and B post-vaccination concomitant with significant rise in PPS-specific IgM memory B cells, a critical B cell subset required for protection against PPS although the overall response remained significantly diminished compared to HIV-negative volunteers.
  
  
  CONCLUSIONS
  Comparable increases in opsonophagocytic titers between study groups A and B concomitant with a comparable rise in PPS-specific IgM memory B cells indicate revaccination to be beneficial regardless of the degree of CD4 T cell reconstitution. These findings emphasize the importance of defining effective vaccination practices amongst high-risk individuals.
authors.affiliation: Department of Medicine, University of Toledo, USA.
authors.forename: Anita S
authors.initials: AS
authors.lastname: Iyer
authors.affiliation: Department of Medicine, University of Toledo, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Leggat
authors.affiliation: Department of Medicine, University of Toledo, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Ohtola
authors.affiliation: Department of Medicine, University of Toledo, USA ; Department of Medical Microbiology and Immunology, University of Toledo, USA ; Department of Internal Medicine, University of Toledo, USA ; Department of Pathology, University of Toledo, USA ; Department of Physiology, University of Toledo, USA ; Department of Pharmacology, University of Toledo, USA ; Department of Metabolism and Cardiovascular Science, University of Toledo, USA.
authors.forename: Joan M
authors.initials: JM
authors.lastname: Duggan
authors.affiliation: Department of Medicine, University of Toledo, USA.
authors.forename: Claudiu A
authors.initials: CA
authors.lastname: Georgescu
authors.affiliation: Department of Medicine, University of Toledo, USA.
authors.forename: Adeeb A
authors.initials: AA
authors.lastname: Al Rizaiza
authors.affiliation: Department of Medicine, University of Toledo, USA ; Department of Public Health, University of Toledo, USA.
authors.forename: Sadik A
authors.initials: SA
authors.lastname: Khuder
authors.affiliation: Department of Medicine, University of Toledo, USA.
authors.forename: Noor M
authors.initials: NM
authors.lastname: Khaskhely
authors.affiliation: Department of Medicine, University of Toledo, USA ; Department of Medical Microbiology and Immunology, University of Toledo, USA ; Department of Internal Medicine, University of Toledo, USA ; Department of Pathology, University of Toledo, USA.
authors.forename: Julie
authors.initials: J
authors.lastname: Westerink
keywords: B cells; HAART; HIV; Immune-response; PPV23-vaccination; Pneumococcal-polysaccharides; Streptococcus pneumoniae