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
| Autor: | Giulia Anderloni, Roberto Rosini, Fabio Rigat, Filippo Carboni, Sceida Khacheh, C. Daniela Rinaudo, Guido Grandi, Roberta Creti, Lucilla Baldassarri, Monica Fabbrini, Immaculada Margarit, John L. Telford, Irene Passalaqua, Domenico Maione |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Microbiology (medical) group B Streptococcus 030106 microbiology medicine.disease_cause Group B Pilus Immunoglobulin G immune response Microbiology Serology Streptococcus agalactiae pilus island 03 medical and health sciences Pregnancy Streptococcal Infections medicine Humans neonatal infection Prospective Studies reproductive and urinary physiology capsular polysaccharide Infectious Diseases Neonatal sepsis biology business.industry Polysaccharides Bacterial medicine.disease Antibodies Bacterial Europe Neonatal infection Fimbriae Bacterial Immunology biology.protein bacteria Female Antibody business Immunity Maternally-Acquired |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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