Human antibody to the group-specific polysaccharide of group B Streptococcus.
IgG antibody to purified group polysaccharide of group B Streptococcus was detected with a specific, reproducible enzyme-linked immunosorbent assay in sera of 178 human subjects: 106 parturient patients, 67 of their healthy infants, and 5 adults with invasive infection. Antibody concentrations in 44 parturient carriers of group B streptococci were significantly greater than in 44 noncarriers (geometric mean level, 3.5 and 1.2 micrograms/ml, respectively). Cord serum levels agreed closely with maternal serum levels. The sera of 18 mothers of infants with early-onset streptococcal infection contained levels (geometric mean level, 5.5 micrograms/ml) similar to those of carriers and significantly higher than noncarriers. Of five adults with invasive group B streptococcal infection, three demonstrated significant increases in antibody titer in consecutive sera, and four had antibody concentrations greater than most (93%) noncarriers. These findings suggest that group B polysaccharide is immunogenic in humans and that levels of specific IgG antibody increase with colonization or infection of adults with group B streptococci.
D000907:Antibodies, Bacterial / Q000032:analysis*; D002353:Carrier State / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D007231:Infant, Newborn; D007743:Labor, Obstetric; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology; D013290:Streptococcal Infections / Q000276:immunology*; D013292:Streptococcus agalactiae / Q000276:immunology*
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D011135:Polysaccharides, Bacterial