Evaluation of the residual antigenicity and allergenicity of cow’s milk substitutes by in vitro tests

DOCENA GUILLERMO; ROZENFELD PAULA; FERNANDEZ RITA; FOSSATI ALBERTO

ALLERGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2002 vol. 57 p. 83 - 91

0105-4538

Background: This study aimed the to investigate presence of residual allergeniccow’s milk proteins (CMP) in some milk substitutes employed in the treatment ofcow’s milk allergy (CMA). These allergens may interfere with the treatment, andelicit allergic reactions in sensitized individuals.Methods: The protein composition of the different extracts was evaluated byLowry’s method and tricine SDS-PAGE. Different immunoenzymatic methodswere used (ELISA, EAST and immunoblotting) to quantify total serum IgE andspecific serum IgE, as well as to detect the presence of antigenic and allergeniccomponents.Results: The results showed a higher protein content in mammalian milks (cow,sheep, mare, goat, and human) than in hydrolyzed substitutes (partially orextensively hydrolyzed casein or whey proteins). Residual native, processed, orcontaminant polypeptides have been identified in the moderate hydrolysates,whereas extensive hydrolysates did not show the presence of residualcomponents by immunoblotting. However, specific antibodies with capacity tobind to peptides have been detected by EAST and ELISA, suggesting thatextensive hydrolysates contain residual peptides that preserve immunoreactiveepitopes. We were unable to demonstrate either residual antigenicity orallergenicity in an amino-acid-based formula.Conclusions: Immunoenzymatic methods were used to detect the presence ofcross-reactive components in mammalian milks. Residual allergenic componentsfrom cow’s milk could be identified in both the moderate and extensivehydrolysates analyzed. This information may be relevant to the treatment ofCMA.