Exercise and aspirin increase levels of circulating gliadin peptides in patients with wheat-dependent exercise-induced anaphylaxis.
ABSTRACT Food-dependent exercise-induced anaphylaxis (FDEIA) is an allergic reaction characteristically induced by intense exercise combined with the ingestion of causative food. Recent reports have shown that aspirin intake is a contributing factor in some patients with FDEIA. Wheat is known to be the most frequent causative food, and the IgE-binding epitopes of a major wheat allergen (omega-5 gliadin) in wheat-dependent exercise induced anaphylaxis (WDEIA) have already been clarified. However, the mechanism of eliciting the symptom in WDEIA remains not fully understood.
The aim of this study was to examine the relationship of serum gliadin levels and allergic symptoms induced by exercise or aspirin in patients with WDEIA.
Six patients with a history of recurrent anaphylaxis associated with wheat ingestion were diagnosed as having WDEIA by the provocation test, which included wheat ingestion, exercise, aspirin intake and a combination of these challenges. During the tests, serum levels of gliadins were monitored by gliadin-specific sandwich ELISA. The effects of exercise and aspirin on serum gliadin levels were also investigated in four healthy subjects.
Immunoreactive gliadins appeared in the sera of patients during the provocation test with both wheat-exercise and wheat-aspirin challenges in parallel with allergic symptoms. Serum gliadin levels also increased under the two same challenge conditions in the healthy subjects, although they exhibited no allergic symptoms. However, low levels of gliadin were detected in the sera of both patients and healthy subjects when challenged with wheat alone.
We demonstrated for the first time that blood gliadin levels correlate with clinical symptoms induced by exercise and aspirin in patients with WDEIA. These findings suggest that exercise and aspirin facilitate allergen absorption from the gastrointestinal tract.
- SourceAvailable from: Kunie Kohno[Show abstract] [Hide abstract]
ABSTRACT: Wheat omega-5 gliadin has been identified as a major allergen in wheat-dependent exercise-induced anaphylaxis. We have detected seven IgE-binding epitopes in primary sequence of the protein. We newly identified four additional IgE-binding epitope sequences, QQFHQQQ, QSPEQQQ, YQQYPQQ and QQPPQQ, in three patients with wheat-dependent exercise-induced anaphylaxis in this study. Diagnosis and therapy of food allergy would benefit from the availability of defined recombinant allergens. However, because omega-5 gliadin gene has not been cloned, recombinant protein is currently unavailable. We sought to clone the omega-5 gliadin gene and produce the homogeneous recombinant protein for use in an in vitro diagnostic tool. Using a PCR-based strategy we isolated two full-length omega-5 gliadin genes, designated omega-5 and omega-5b, from wheat genomic DNA and determined the nucleotide sequences. The protein encoded by omega-5a was predicted to be 439 amino acids long with a calculated mass of 53 kDa; the omega-5b gene would encode a 393 amino acid, but it contains two stop codons indicating that omega-5b is pseudogene. The C-terminal half (178 amino acids) of the omega-5a gliadin protein, including all 11 IgE-binding epitope sequences, was expressed in Escherichia coli by means of the pET system and purified using RP-HPLC. Western blot analysis and dot blot inhibition assay of recombinant and native omega-5 gliadin purified from wheat flour demonstrated that recombinant protein had IgE-binding ability. Our results suggest that the recombinant protein can be a useful tool for identifying patients with wheat-dependent exercise-induced anaphylaxis in vitro.FEBS Journal 10/2005; 272(17):4431-8. DOI:10.1111/j.1742-4658.2005.04858.x · 3.99 Impact Factor
- Journal of investigational allergology & clinical immunology: official organ of the International Association of Asthmology (INTERASMA) and Sociedad Latinoamericana de Alergia e Inmunología 02/2009; 19(4):337. · 2.64 Impact Factor
- Acta Dermato Venereologica 09/2012; 92(5):451-453. DOI:10.2340/00015555-1211 · 4.24 Impact Factor