[IgG subclasses against bovine alpha-lactalbumin and beta-lactoglobulin in infants fed with a seroprotein hydrolysate]

Prevention of food allergy in infancy has been the aim of important researches in the last years but many studies have produced conflicting conclusions. The use of hydrolysate formulas seems to be an helpful tool in prevention of cow milk protein allergy but confusion often remains about capability of small hydrolysate molecules to be "allergens" or "antigens". In order to clarify this point IgE, IgG and IgM as well as IgG subclasses against alfa-lactoalbumin (ALA) and beta-lactoglobulin (BLG) have been evaluated in 41 infants at risk for allergy and in 30 controls at the fourth month. The same evaluation has been done on their mothers. The 41 "at risk" children were fed with breast milk or with an hypoallergenic formula (Nidina HA, Nestlè) or both. The control children received an adapted formula. No difference between the two groups of children was found regarding IgM or IgG against ALA while antibodies against BLG were more frequently found in controls than in "at risk" children. Only one child in the group fed with Nidina HA developed specific IgE against whole milk. Therefore hydrolysate formula seems to be as antigenic (not allergenic) as adapted formula in respect of ALA while BLG contained in adapted formula seems to be a stronger immunogen. The pattern of specific IgG subclasses against ALA and BLG is different between the two groups of children because of the absence in "at risk" group of specific IgG2 and IgG3. As for the mothers, the presence in their sera of IgG against ALA or BLG seems to induce in infants a reduced response to the same antigen.