The Protective Value of Maternal Group B Streptococcus Antibodies: Quantitative and Functional Analysis of Naturally Acquired Responses to Capsular Polysaccharides and Pilus Proteins in European Maternal Sera.
Clin Infect Dis
; 63(6): 746-753, 2016 09 15.
Article
em En
| MEDLINE
| ID: mdl-27402816
ABSTRACT
BACKGROUND:
Group B Streptococcus (GBS) is a major cause of neonatal sepsis and meningitis. A vaccine targeting pregnant women could protect infants through placentally transferred antibodies. The association between GBS maternal antibody concentrations and the risk of neonatal infection has been investigated in US and African populations. Here we studied naturally acquired immunoglobulin G (IgG) responses to GBS capsular polysaccharides (CPS) and pilus proteins in European pregnant women.METHODS:
Maternal sera were prospectively collected in 8 EU countries from 473 GBS non-colonized and 984 colonized pregnant women who delivered healthy neonates and from 153 mothers of infants with GBS disease. GBS strains from these colonized women and infected infants were obtained in parallel and their capsular and pilus types were identified by serological and molecular methods. Maternal serum concentrations of IgG anti- Ia, -Ib, -III and -V polysaccharides and anti-BP-1, -AP1-2a and -BP-2b pilus proteins were determined by enzyme-linked immunosorbent assay. Antibody functional activity was quantified by Opsonophagocytic Killing Assay.RESULTS:
Antibody levels against CPS and pilus proteins were significantly higher in GBS colonized women delivering healthy babies than in mothers of neonates with GBS disease or non-colonized women. Moreover, maternal anti-capsular IgG concentrations showed a significant correlation with functional titers measured by Opsonophagocytic Killing Assay.CONCLUSIONS:
Maternal anti-capsular IgG concentrations above 1 µg/mL mediated GBS killing in vitro and were predicted to respectively reduce by 81% (95% confidence interval, 40%-100%) and 78% (45%-100%) the risk of GBS Ia and III early-onset disease in Europe.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polissacarídeos Bacterianos
/
Infecções Estreptocócicas
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Streptococcus agalactiae
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Fímbrias Bacterianas
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Imunidade Materno-Adquirida
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Anticorpos Antibacterianos
Tipo de estudo:
Observational_studies
/
Prognostic_studies
Limite:
Female
/
Humans
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Pregnancy
País/Região como assunto:
Europa
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article