Transforming growth factor-beta 1 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 und erdeveloped defenses of the gut of the newborn infant. Objective: Ne 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 i nfants and collected samples of colostrum from mothers. Samples from mother s of infants with CMA and from control subjects were analyzed for immunoglo bulins, CM-specific antibodies, and cytokines. In infants with CMA,: correl ations between the concentration of transforming growth factor (TGF)-beta 1 in colostrum and the extent of the immune response to Chi proteins were st udied. Results: The concentration of TGF-beta 1 in colostrum samples from mothers of infants with IgE-mediated CMA (n = 65) was lower (mean, 589 pg/mL; 95% c onfidence 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 = .0 12). 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-be ta 1 in colostrum was positively correlated with IgA antibodies to beta-lac toglobulin and IgG antibodies to alpha-casein and whole formula and negativ ely with the diameter of a skin prick test response to CM and lymphocyte st imulation indices to alpha-casein and beta-lactoglobulin. Conclusions: In an infant prone to having CR-LA, the TGF-beta 1 content of mother's colostrum may promote IgG-IgA antibody production and inhibit IgE- and cell-mediated reactions to CM.