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Dextran-reactive antibodies in healthy infants and toddlers--relation to type of feeding
Insights
Dextran-reactive antibodies (DRA) emerge in infants within the first year, influenced by diet. Breastfeeding delays DRA appearance but increases titers in positive cases, suggesting gut flora as a key factor.
Area of Science:
- Immunology
- Pediatrics
- Microbiome research
Background:
- Dextran-reactive antibodies (DRA) are present in healthy adults.
- The origin and developmental timeline of DRA in infants are not well understood.
Purpose of the Study:
- To investigate the appearance and development of DRA in infants during the first two years of life.
- To explore the influence of feeding type, immunizations, and blood group on DRA emergence.
Main Methods:
- Passive hemagglutination assay used to detect DRA in sera from 88 healthy newborns.
- Longitudinal study tracking antibody levels at 3, 8, and 27 months of age.
- Correlation analysis with feeding methods (breast milk vs. formula), immunizations, and maternal/infant blood groups.
Main Results:
- DRA were undetectable at birth but appeared in 42% by 3 months, 95% by 8 months, and 84% by 27 months.
- Peak DRA titers were observed at 8 months.
- Breastfeeding was associated with a delayed appearance of DRA and higher titers in positive cases compared to formula feeding.
Conclusions:
- DRA emerge during infancy, with significant influence from exogenous factors, primarily feeding.
- The gastrointestinal flora, altered by the introduction of cow's milk, is the likely source of antigen stimulation for DRA.
- Infant feeding practices play a crucial role in the development of the antibody response to dextran.
Abstract:
The appearance of dextran-reactive antibodies (DRA) during the first 2 years of life was studied in 88 healthy newborn babies in an effort to provide information about the origin of DRA in normal persons. The results were related to type of feeding, immunizations and to blood group of infants and their mothers. No DRA were detected in cord sera by passive hemagglutination. At 3 months of age 42% had DRA, at 8 months 95% and at 27 months 84%. The latter figure corresponds to previous reports of DRA in healthy adults. Peak titers were also seen at 8 months (mean 2 log titers at 3, 8 and 27 months; 2.1, 6.2 and 4.9, respectively). Breast-feeding influenced the time of appearance of DRA and the magnitude of the titers. Babies breast-fed at 3 months more often were DRA negative than those that had received cow's milk-based formula at that time (p less than 0.005). However, in those breast-fed babies that were DRA positive the titers were higher than in the formula-fed infants (p less than 0.001). Other types of feeding e.g. juices did not influence the DRA levels. The appearance of DRA could not be explained by polyclonal stimulation of antibody production since changes of DRA titers in 11 tested patients could not be clearly related to similar changes of levels of antibodies to an unrelated hapten, trinitrophenyl. The study demonstrates that DRA appear during the first year of life, and that the appearance is influenced by exogenous factors. The most likely source of the antigen stimulation is the gastrointestinal flora which is altered by introduction of cow's milk into the diet.