Temporary neonatal exposure to whole and hydrolysed cow's milk proteins. Studies of macromolecular absorption and immunological variables

Sammanfattning: The aim of this work was to study prospectively the effects of different feeding regimens during the first three days of life. A group of 129 infants were randomly assigned at birth to one of three feeding regimens: human milk (HM), cow's milk formula (CMF), or a casein hydrolysate formula (CHF). The formula-fed infants received no human milk until the fourth day of life, after which all infants were breast- fed for a varying period of time. During a 2 years follow-up, effects of different feeding regimens on macromolecular absoprtion (serum content of human alpha-lactalbumin, alpha-LA), antibody production, and development of allergic symptoms were studied. Macromolecular absorption was also studied in 28 children with acute symptoms of cow's milk allergy and in 76 children in relation to cow's milk challenge. Higher concentrations of S-alpha-LA were found at two months of age in the CHF group than either in the HM or the CMF group. Higher concentrations were also recorded in children who developed a clinical reaction to cow's milk challenge than in those manifesting no reaction.Children with acute symptoms of cow's milk allergy, before treatment with cow's milk free diet had higher levels of alpha-LA than healthy children. Median total S-IgE levels were lower in the CHF group than in the HM group at 2 and 8 months of age. The levels of IgG antibodies to beta-lactoglobulin were higher in the CMF and in the HM group than in the CHF group up to two years. This was particularly obvious in infants who were exclusively breast-fed for longer than two months. There was no significant difference in secretory IgA (sIgA) levels in saliva of infants between the three groups. No correlation was found between the frequency of atopic symptoms in the infants and in the IgG antibody levels or salivary sIgA levels in the infants. The sIgA levels were higher in colostrum than in mature milk. In conclusion, exposure to cow's milk during the first three days of life stimulated IgG antibody production to cow's milk proteins. Casein hydrolyste given neonatally seems to depress the infant's immuno- competence by decreasing production of IgE, and by decreasing IgG antibody production to cow's milk proteins. Exposure to casein hydrolysate was associated with increased absorption of macro- molecules at two months of age.