IgG and IgA antibody levels to cow's milk are low at age 10 years in children born preterm.
BACKGROUND
Both innate and specific defenses of the preterm infant are even less developed than those of term infants, and the immune systems of preterm infants might be skewed differently at birth. Their immune responses to food antigens started early in life might therefore differ from those of term infants.


OBJECTIVE
We sought to compare antibody levels to cow's milk, ovalbumin, and gliadin at age 10 years in children who had been born either preterm or at term.


METHODS
IgG and IgA isotype antibodies to whole cow's milk, beta-lactoglobulin, alpha-casein, and ovalbumin, as well as IgG antibody levels to gliadin and to tetanus and diphtheria toxoids, were measured for a group of 62 children born preterm and 61 control subjects born at term. These children were studied at the same time for atopy.


RESULTS
Children born preterm had markedly lower levels of antibodies to cow's milk and to its protein fractions (P <.0001 for IgA and IgG antibodies to cow's milk and alpha-casein and IgG beta-lactoglobulin antibodies). IgG gliadin antibodies were also significantly lower in the preterm group (P =.03), although the difference was not significant for IgG ovalbumin antibodies. In the preterm group both those born before gestational week 30 and those given cow's milk-based formula early (before day 50) had the lowest levels of cow's milk antibodies. In the preterm group atopy was associated with low levels of IgG cow's milk antibodies but with high levels of IgG ovalbumin antibodies.


CONCLUSIONS
Early introduction of food antigens into the immature gastrointestinal tract of preterm infants might result in tolerance. The presence of less atopy in these children might also be a result of tolerance development.
Siltanen
Mirjami
M
Hospital for Children and Adolescents, University of Helsinki, FIN-0029 HUS, Helsinki, Finland.
Kajosaari
Merja
M
Savilahti
Emma M
EM
Pohjavuori
Maija
M
Savilahti
Erkki
E
D000818:Animals; D000906:Antibodies / Q000032:analysis*; D002648:Child; D005260:Female; D005903:Gliadin / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007070:Immunoglobulin A / Q000032:analysis*; D007074:Immunoglobulin G / Q000032:analysis*; D007225:Infant Food; D007231:Infant, Newborn; D007234:Infant, Premature / Q000276:immunology*; D008297:Male; D008892:Milk / Q000276:immunology*; D008894:Milk Proteins / Q000276:immunology; D010047:Ovalbumin / Q000276:immunology; D012016:Reference Values
D000906:Antibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008894:Milk Proteins; D010047:Ovalbumin; D005903:Gliadin