Maternal-fetal transfer of pneumococcal capsular polysaccharide antibodies
D. S. Chudwin, D. W. Wara, G. Schiffman, S. G. Artrip and A. J. Ammann
Maternal-fetal transfer of IgG antibodies is an important host defense for
newborns, who have an increased incidence of bacterial infections. To study
the transfer of specific pneumococcal capsular polysaccharide (PPS)
antibodies, we measured the concentrations, in 30 paired maternal and cord
serum samples, of IgG and IgM by radial immunodiffusion, of serotype 7F
Streptococcus pneumoniae PPS antibodies by radioimmunoassay and enzyme
immunoassay, and of opsonic activity to that organism by a radiolabeled
bacterial uptake assay. Cord serum had significantly greater total IgG, yet
significantly less type 7F PPS IgG antibodies and opsonic activity than
maternal serum. Cord serum had low concentrations of total IgM and no IgM
type 7F-specific antibodies. Reduced transport of specific IgG antibodies
and absent transfer of IgM may contribute to the susceptibility of newborns
to bacterial infection.
