Wheat IgE-Mediated Food Allergy in European Patients: alpha-Amylase Inhibitors, Lipid Transfer Proteins and Low-Molecular-Weight Glutenins.

Background: three main problems hamper the identification of wheat food allergens: 1) lack of a standardized procedure for extracting all of the wheat protein fractions; 2) absence of double-blind, placebo-controlled food challenge studies that compare the allergenic profile of Osborne’s three protein fractions in subjects with real wheat allergy; 3) lack of data on the differences in IgE-binding capacity between raw and cooked wheat. Methods: sera of 16 wheat challenge positive patients and 6 with wheat anaphylaxis were used for SDS-PAGE/immunoblotting of the three Osborne’s protein fractions (albumin/globulin, gliadins, glutenins) of raw and cooked wheat. Thermal sensitivity of wheat LTP was investigated by spectroscopic approaches. IgE cross-reactivity between wheat and grass pollen was studied by blot inhibition. Results: The most important wheat allergens were the alpha-amylase/trypsin inhibitor subunits, which were present in all three protein fractions of raw and cooked wheat. Other important allergens were a 9-kd lipid-transfer-protein in the albumin/globulin fraction and several low-molecular weight glutenin subunits in the gluten fraction.........................