Allergy to bovine beta-lactoglobulin: specificity of human IgE using cyanogen bromide-derived peptides.

Background: Bovine beta-Lactoglobulin (Blg) is a major allergen involved in allergy to cow's milk proteins. Hydrolyzing Blg did not totally suppress its allergenicity; moreover its immunoreactivity may be increased. The aim of this work was to evaluate the specificity of serum IgE to different fragments of Blg in a group of 19 individuals allergic to cow's milk.

Methods: This study was performed using both direct and competitive inhibition ELISA involving immobilized native protein or peptides derived from Blg cyanogen bromide cleavage.

Results: Analyses of responses to each peptide revealed a large number of epitopes recognized by specific IgE of human allergic sera. However, there were differences in the specific determinants recognized, depending on the serum. Generally, peptides (25-107) and (108-145) retained substantial proportions of the immunoreactivity of the whole protein. Two other peptides, i.e. (8-24) and (146-162), were less recognized but were not inert.

Conclusion: The main conclusion is that many epitopes were identified all along the Blg sequence by specific anti-Blg IgE from allergic humans.