Cow's milk proteins/allergens.

OBJECTIVE: The primary objective of this review is to provide updated data on the structure and function of the main cow's milk proteins (CMPs) identified as allergens and on the characterization of their epitopes. DATA SOURCES: The review represents a synthesis of basic literature and most relevant original recent publications on both topics of clinical and epidemiologic aspects of milk allergy and of milk protein's bio- and immunochemistry. STUDY SELECTION: The expert opinion of the author was used to select the relevant data for the review.
RESULTS: Most CMPs are potential allergens, even the proteins present at very low concentration. There are both conformational and linear epitopes, widely spread all along the protein molecules. They may be short fragments, located in hydrophobic parts of the molecule which comprise highly conserved sequences responsible for immunoglobulin E cross-reactivity with corresponding milk proteins of other mammals, including human beings. Those sequential epitopes have also been proposed as good markers of persistent allergy to CMPs.
CONCLUSIONS: No specific structure nor function is associated with allergenicity of CMPs. Variability and heterogeneity of the human immunoglobulin E response preclude anticipating the allergenic potential of any CMP or fragment thereof, as well as justify the need for being careful before using peptides for desensitization or proposing any milk protein hydrolysate in a diet for highly allergenic children.