Development of immunoglobulin G and immunoglobulin E antibodies to cow's milk proteins and ovalbumin after a temporary neonatal exposure to hydrolyzed and whole cow's milk proteins

The ingestion of food antigens usually results in the induction of oral tol erance, but the clinical and immunologic consequences of brief exposure to cow's milk proteins during the neonatal period are not well-documented. The aim of this work was to study immunoglobulin (Ig)E and IgG responses to co w's milk proteins and ovalbumin after exposure during the first three days of life in infants who were otherwise exclusively breast-fed. A group of 12 9 infants was randomly assigned at birth to one of three feeding regimens: human milk (HM), cow's milk formula (CMF), or a casein hydrolysate formula (CHF), during the first three days of life. They were then all exclusively breast-fed for a varying period of time and followed for two years. Serum I gG and IgE antibodies to cow's milk proteins and ovalbumin (OVA) were analy zed in blood samples obtained at birth, at 4 days and at 2, 4, 8, 12 and 24 months of age. The levels of IgG antibodies to beta-lactoglobulin (IgG-BLG ) and bovine serum albumin (IgG-BSA) were higher in the CMF and the HM grou ps than in the CHF group for up to two years. This was particularly obvious for IgG-BLG in infants who started weaning before two months, The levels o f IgG antibodies to casein (IgG-CAS) were higher in the CMF goup, as compar ed with the CHF group at 8 and 12 months. The levels of IgG antibodies to O VA were similar in all three feeding groups. The levels of IgE antibodies t o CAS or OVA were similar in the three feeding groups. Exposure to cow's mi lk during the first three days of life stimulated IgG antibody production t o cow's milk proteins and this was still obvious at 2 years of age, while f eeding with a casein hydrolysate during the first three days of life was as sociated with low levels of IgG antibodies to cow's milk proteins.