RESIDUAL ANTIGENICITY OF HYPOALLERGENIC INFANT FORMULAS AND THE OCCURRENCE OF MILK-SPECIFIC IGE ANTIBODIES IN PATIENTS WITH CLINICAL ALLERGY

Background: Milk protein hydrolysates are frequently used in milk subs titutes for children with cow's milk allergy. However, cases of hypers ensitivity to commercially available hypoallergenic infant formulas ba sed on milk protein hydrolysates have been reported. Objective: Our pu rpose was to determine the immunologic response of milk protein-specif ic IgE and IgG in the serum of patients allergic to cow's milk against foul commercially available hypoallergenic milk protein hydrolysates and eight infant formulas. Methods: Antibody levels in patients' serum and milk protein-specific residual antigenicity of the hypoallergenic products were determined by indirect and competitive ELISA. Results: Patients allergic to cow's milk had IgE and Ige antibodies to several protein fractions of cow's milk; intraindividual and interindividual v ariation in the concentrations of these antibodies was considerable. I n general, IgE and IgG residual antigenicity of individual milk protei ns in the hypoallergenic products was lower compared with that of the intact milk protein bur immunoreactive epitopes could still be detecte d in all products. Their number varied considerably among the individu al milk proteins and also differed among products. Conclusions: The in dividual sensitization pattern of the patient allergic to cow's milk a nd the milk protein-specific residual antigenicity might be considered as possible laboratory predictors of adverse reactions to hypoallerge nic products. Their determination could be a useful preclinical screen ing test for pediatricians to select a formula adapted to the individu al patient.