Identification of wheat flour allergens by means of 2-dimensional immunoblotting

Humoral and cellular responses to gliadin in wheat-dependent, exercise-induced anaphylaxis

BACKGROUND

Wheat-dependent, exercise-induced anaphylaxis (WDEIA) is a severe allergy where wheat ingestion together with physical exercise induces anaphylaxis. We have previously shown that patients with WDEIA have IgE antibodies against gliadin proteins and identified omega-5 gliadin (Tri a 19) as a major allergen.

OBJECTIVE

The aim of this study was to examine gliadin-specific IgG subclass, IgA and IgE antibodies, basophil histamine release and cell-mediated responses in WDEIA.

METHODS

Sera and peripheral blood mononuclear cells (PBMC) were obtained from patients with WDEIA and from controls without wheat allergy. Serum antibodies to crude gliadin extract (CGE) and purified omega-5 gliadin were measured by ELISA and basophil reactivity by histamine-release test. Gliadin-induced cell-mediated responses were assessed by lymphocyte proliferation assay, and cytokine mRNA expression with real-time quantitative PCR.

RESULTS

All patients with WDEIA, but none of the controls, had IgE antibodies to CGE and omega-5 gliadin. Both allergens released high levels of histamine from the basophils of patients with WDEIA. Levels of IgA antibodies to CGE and omega-5 gliadin were significantly elevated in the patients, but the distribution of IgG subclass antibodies showed no statistically significant differences between the two groups. Proliferative responses of PBMC to CGE were increased in patients with WDEIA, and stimulation of PBMC with CGE caused, both in patients and in controls, a clear induction of IL-10 mRNA. Compared with the controls, induction of IL-10 mRNA expression in patients with WDEIA was significantly (P < 0.01) suppressed.

CONCLUSION

These results suggest that, in addition to IgE antibodies against omega-5 gliadin, specific IgA antibodies may be involved in the pathogenesis of WDEIA. Decreased expression of IL-10 mRNA in PBMC during gliadin stimulation may facilitate the development of gliadin-specific T cell responses.

Mitigation of the action of wheat allergen by acidic oxidative potential water

BACKGROUND

Acidic oxidative potential water (AOPW) is strongly acidic, and contains active oxygen species and thus exhibits an oxidative potential to cause biochemical alterations of wheat proteins.

METHODS

A commercial wheat allergen extract was treated with AOPW, and then analysed by means of SDS-PAGE and the skin prick test in IgE-mediated wheat allergic patients.

RESULTS

The wheat extract comprised 70 kDa, 32 kDa and 30 kDa fractions, and the protein in the 70 kDa fraction was broken down into less than 14 kDa fractions by AOPW. AOPW mitigated 39% of the wheal reaction to the wheat extract in the skin prick test.

CONCLUSION

AOPW may be useful for enhancing the digestibility and lowering the allergenicity of wheat proteins.

Occupational reactions to foods

The spectrum of occupational diseases most commonly seen in the food industry includes occupational asthma, rhinitis, conjunctivitis, dermatitis, and hypersensitivity pneumonitis. Occupational asthma represents between 3% and 20% of all asthma cases and is the most common form of occupational lung disease. Occupational skin diseases may represent between 10% and 15% of all occupational diseases, and they have significant economic impact. Hypersensitivity pneumonitis affects the food industry, with farmer's lung representing a common form of the disease. Each of these diseases may have serious and potentially irreversible effects on the health of a farmer, food processor, or food preparer, even after removal of the offending exposure.