Effects of maternal diet during late pregnancy and lactation on the development of IgE and egg- and milk-specific IgE and IgG antibodies in infants.

The IgE levels and food-allergen-specific IgE- and IgG-antibodies (Ab) to ovalbumin (OA), ovomucoid (OVO) and beta-lactoglobulin (BLG) were determined up to 18 months of age in 163 infants born to women who were atopic. A high (HIGH group) or a low (REDUCED group) intake of hen's egg and cow's milk by the mother during the third trimester gave no significant differences in the concentrations of IgE or in IgE-Ab (OVO, BLG) and IgG-Ab (OA, OVO, BLG). Similarly, a prolongation of the abstention diet to the early lactation period did not influence the immune response. The IgG-Ab levels to all three food allergens decreased significantly (P less than 0.001) in both study groups between birth and 2 months of age, but then increased significantly (P less than 0.001) between 6 and 18 months of age. The presence in serum of IgE-Ab to OVO (greater than or equal to 0.15 PRU/ml) was associated with significantly higher IgG-Ab levels to OVO at 6 months (P less than 0.001) and at 18 months (P less than 0.05). Infants with positive skin-prick tests (SPT) to OA and OVO showed higher IgG-Ab levels at 6 and 18 months of age than did infants with negative SPT reactions to the two egg allergens. This indicates a relation between the IgE- and IgG-Ab response and it also suggests that some individuals are 'high responders' to both types of immunoglobulin isotypes while others are 'low responders'.