title: Placental transfer of anti-group B Streptococcus immunoglobulin G antibody subclasses from HIV-infected and uninfected women to their uninfected infants.
abstract: OBJECTIVE
  Placental antibody transfer is impaired in the context of HIV infection, which may render HIV-exposed, uninfected infants vulnerable to group B Streptococcus (GBS) disease. The GBS antibody response predominately consists of immunoglobulin G2 (IgG2) antibody. Thus we determined whether concentration and placental transfer of anti-GBS antibody subclasses was altered in HIV-infected compared with HIV-uninfected mothers.
  
  
  METHODS
  A retrospective analysis of anti-GBS antibody subclasses in 38 HIV-infected and 33 HIV-uninfected mothers and their uninfected infants.
  
  
  METHODS
  Sera were analysed using a novel flow cytometric assay that quantified binding of IgG1, IgG2, IgG3 and IgG4 to serotype (ST)Ia, STIII and STV GBS bacteria.
  
  
  RESULTS
  IgG2 binding to GBS STIa and V was lower in HIV-infected women compared with HIV-uninfected women. Moreover, IgG2 binding to GBS STIa was also lower in HIV-exposed, uninfected infants compared with unexposed infants. However, there were no statistically significant differences in the transplacental transfer ratio of IgG2 for any GBS serotype. The transplacental transfer of total IgG was reduced for GBS STIII and V and IgG1 subclass for STIII; placental transfer of all other subclasses was comparable in HIV-affected and HIV-unaffected pregnancies.
  
  
  CONCLUSIONS
  Anti-GBS IgG2 placental transfer is not affected by HIV infection. This is important for functional antibody against the capsular polysaccharide of GBS and provides confidence that maternal GBS vaccination may result in functional activity in HIV-infected and uninfected women.
authors.affiliation: aCentre for International Child Health and Department of Academic Paediatrics, Imperial College, London bPaediatric Infectious Diseases Research Group, Institute for Infection and Immunity St George's, University of London, London, UK cVaccines and Immunity Theme, Medical Research Council Unit, Fajara, The Gambia dPublic Health England, Porton Down, Salisbury, UK eDepartment of Pediatrics and Child Health, Desmond Tutu TB Center, Stellenbosch University fInstitute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
authors.forename: Kirsty
authors.initials: K
authors.lastname: Le Doare
authors.forename: Stephen
authors.initials: S
authors.lastname: Taylor
authors.forename: Lauren
authors.initials: L
authors.lastname: Allen
authors.forename: Andrew
authors.initials: A
authors.lastname: Gorringe
authors.forename: Paul T
authors.initials: PT
authors.lastname: Heath
authors.forename: Beate
authors.initials: B
authors.lastname: Kampmann
authors.forename: Anneke C
authors.initials: AC
authors.lastname: Hesseling
authors.forename: Christine E
authors.initials: CE
authors.lastname: Jones
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D007231:Infant, Newborn; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology*; D012189:Retrospective Studies; D013292:Streptococcus agalactiae / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G