title: Antibody Response is More Likely to Pneumococcal Proteins Than to Polysaccharide After HIV-associated Invasive Pneumococcal Disease.
abstract: BACKGROUND
  Human immunodeficiency virus (HIV)-infected individuals are at increased risk of invasive pneumococcal disease (IPD). In order to assess the immunogenicity of pneumococcal proteins and polysaccharide, we investigated protein and serotype-specific antibody responses after HIV-associated IPD.
  
  
  METHODS
  Specific antipneumococcal immunoglobulin G to 27 pneumococcal protein antigens and 30 serotype polysaccharides was measured in plasma before and after IPD in HIV-infected individuals and compared to HIV-infected individuals without IPD.
  
  
  RESULTS
  Over time, 81% of IPD cases responded to at least 1 protein compared to 51% of non-IPD controls. HIV IPD cases responded to more proteins than non-IPD controls (8.6 ± 8.4 vs 4.2 ± 7.6 proteins; P = .01), and had a significantly higher probability of yielding an antibody response to the proteins PiaA, PsaA, and PcpA. Twenty-two percent of HIV-infected individuals with IPD had a serotype-specific antibody response. Younger age at the time of IPD was the only predictor of a serotype-specific pneumococcal antibody response, whereas we did not identify predictors of a protein-specific antibody response.
  
  
  CONCLUSIONS
  Antibody responses occurred more frequently to pneumococcal proteins than to polysaccharide, and protein antibodies persisted for longer than polysaccharide-specific antibodies. PcpA, PiaA, and PsaA were the most immunogenic proteins.
authors.affiliation: Department of Microbiological Diagnostics and Virology, Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Bjørn
authors.initials: B
authors.lastname: Kantsø
authors.affiliation: Immunobiology Unit, Institute of Child Health, University College London, United Kingdom.
authors.forename: Nicola
authors.initials: N
authors.lastname: Green
authors.affiliation: Immunobiology Unit, Institute of Child Health, University College London, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Goldblatt
authors.affiliation: Department of Infectious Diseases Clinical Research Centre, Hvidovre Hospital Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Benfield
mesh_terms: D018829:Adhesins, Bacterial / Q000276:immunology; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D023241:Antiretroviral Therapy, Highly Active; D001426:Bacterial Proteins / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D047908:Intracellular Signaling Peptides and Proteins; D008074:Lipoproteins / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000150:complications / Q000276:immunology*; D011134:Polysaccharides / Q000276:immunology; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000276:immunology*
chemical_list: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D007074:Immunoglobulin G; D047908:Intracellular Signaling Peptides and Proteins; D008074:Lipoproteins; C113653:PcpA protein, Streptococcus; D011134:Polysaccharides; C085000:PsaA protein, Streptococcus
keywords: HAART; HIV; IPD; Streptococcus pneumoniae; antibody; pneumococcal vaccines; pneumococcus