Wheat IgE-mediated food allergy in European patients: alpha-amylase inhibitors, lipid transfer proteins and low-molecular-weight glutenins. Allergenic molecules recognized by double-blind, placebo-controlled food challenge.

Abstract

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, and (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 patients with wheat anaphylaxis, recruited from Italy, Denmark and Switzerland, were used for sodium dodecyl sulfate-polyacrylamide gel electrophoresis/immunoblotting of the three Osborne's protein fractions (albumin/globulin, gliadins and glutenins) of raw and cooked wheat. Thermal sensitivity of wheat lipid transfer protein (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-kDa LTP in the albumin/globulin fraction and several low-molecular-weight (LMW) glutenin subunits in the gluten fraction. All these allergens showed heat resistance and lack of cross-reactivity to grass pollen allergens. LTP was a major allergen only in Italian patients.

CONCLUSIONS:

The alpha-amylase inhibitor was confirmed to be the most important wheat allergen in food allergy and to play a role in wheat-dependent exercise-induced anaphylaxis, too. Other important allergens were LTP and the LMW glutenin subunits.

• Authors: Elide A Pastorello, Laura Farioli, Amedeo Conti, Valerio Pravettoni, Simona Bonomi, Stefania Iametti, Donatella Fortunato, Joseph Scibilia, Carsten Bindslev-Jensen, Barbara Ballmer-Weber, Anna M Robino, Claudio Ortolani
• Journal: International archives of allergy and immunology (Int Arch Allergy Immunol) Vol. 144 Issue 1 Pg. 10-22 ( 2007) ISSN: 1423-0097 [Electronic] Switzerland
• PMID: 17496422 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)

Chemical References

• Allergens
• Antigens, Plant
• Carrier Proteins
• Enzyme Inhibitors
• Placebos
• Plant Proteins
• Trypsin Inhibitors
• lipid transfer proteins, plant
• Immunoglobulin E
• Glutens
• alpha-Amylases
• glutenin

Topics

• Adult
• Allergens (immunology, metabolism)
• Amino Acid Sequence
• Antigens, Plant (immunology, metabolism)
• Carrier Proteins (immunology, metabolism)
• Child, Preschool
• Double-Blind Method
• Enzyme Inhibitors (immunology, metabolism)
• Europe
• Female
• Food Hypersensitivity (enzymology, immunology, metabolism)
• Glutens (chemistry, immunology, metabolism)
• Humans
• Immunoglobulin E (biosynthesis, blood, physiology)
• Infant
• Male
• Middle Aged
• Molecular Sequence Data
• Molecular Weight
• Placebos
• Plant Proteins (immunology, metabolism)
• Triticum (chemistry, immunology)
• Trypsin Inhibitors (metabolism)
• alpha-Amylases (antagonists & inhibitors)