Transforming growth factor-beta1 in mothers' colostrum and immune responses to cows' milk proteins in infants with cows' milk allergy.

BACKGROUND

Breast milk contains immune factors that compensate for the underdeveloped defenses of the gut of the newborn infant.

OBJECTIVE

We sought to study the importance of these factors in the immune responses of infants with cows' milk allergy (CMA) to the proteins in cows' milk (CM).

METHODS

We prospectively followed the development of CMA in 6209 healthy infants and collected samples of colostrum from mothers. Samples from mothers of infants with CMA and from control subjects were analyzed for immunoglobulins, CM-specific antibodies, and cytokines. In infants with CMA, correlations between the concentration of transforming growth factor (TGF)-beta1 in colostrum and the extent of the immune response to CM proteins were studied.

RESULTS

The concentration of TGF-beta1 in colostrum samples from mothers of infants with IgE-mediated CMA (n = 65) was lower (mean, 589 pg/mL; 95% confidence interval [CI], 413-840) than from mothers of infants with non-IgE-mediated CMA (n = 37; mean, 1162 pg/mL; 95% CI, 881-1531; t = 2.57, P =.012). In 126 control subjects the mean concentration was 807 pg/mL (95% CI, 677-963). In the infants with CMA (n = 96-100), the concentration of TGF-beta1 in colostrum was positively correlated with IgA antibodies to beta-lactoglobulin and IgG antibodies to alpha-casein and whole formula and negatively with the diameter of a skin prick test response to CM and lymphocyte stimulation indices to alpha-casein and beta-lactoglobulin.

CONCLUSIONS

In an infant prone to having CMA, the TGF-beta1 content of mother's colostrum may promote IgG-IgA antibody production and inhibit IgE- and cell-mediated reactions to CM.