Maternofetal transfer of IgG anti-Escherichia coli antibodies with enhanced avidity and opsonic activity in very premature neonates.
Total IgG concentrations, IgG antibody concentrations to pooled Escherichia coli antigens, and IgG anti-E. coli antibody avidity were measured in cord and maternal serum samples collected from 52 mother-infant pairs after premature delivery (mean gestational age 28 wk, range 23-33 wk). The mean IgG anti-E. coli antibody concentration in cord serum (1.86 relative units/mL) was markedly lower than in maternal serum (5.42 relative units/mL) at this gestation (p less than 0.0001). Cord serum IgG anti-E. coli antibody concentrations correlated closely with maternal IgG anti-E. coli concentrations when controlled for the effect of gestational age (partial correlation coefficient 0.89; p less than 0.001) but only weakly with gestational age when controlled for maternal IgG antibody concentrations (partial correlation coefficient 0.23; p = 0.06). The mean ratio of cord to maternal IgG anti-E. coli antibody concentrations was considerably lower than the mean ratio for total IgG concentrations (0.34 versus 0.72; p less than 0.001). The mean avidity of IgG antibody for the pooled E. coli antigens was significantly greater in cord serum than in maternal serum (2.45 versus 1.99M; p less than 0.0001). There was a close correlation between cord and maternal antibody avidity (r = 0.70; p less than 0.001), but cord IgG antibody avidity did not correlate with gestational age (r = -0.07; p = 0.61), nor with cord IgG anti-E. coli antibody concentrations (r = 0.10; p = 0.50).(ABSTRACT TRUNCATED AT 250 WORDS)
Sennhauser
F H
FH
Department of Immunology, University of Melbourne, Royal Children's Hospital, Australia.
Balloch
A
A
Macdonald
R A
RA
Shelton
M J
MJ
Roberton
D M
DM
D000907:Antibodies, Bacterial / Q000378:metabolism*; D000915:Antibody Affinity; D004926:Escherichia coli / Q000276:immunology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D007231:Infant, Newborn; D007234:Infant, Premature / Q000276:immunology*; D008431:Maternal-Fetal Exchange / Q000276:immunology*; D009895:Opsonin Proteins / Q000378:metabolism; D011247:Pregnancy
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D009895:Opsonin Proteins