Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a severe IgE-mediated allergic reaction provoked by the combination of wheat-ingestion with intensive physical exercise over the next few hours. Among wheat proteins, -5 gliadin, which is one of the components of fast -gliadin, has been reported as a major allergen in the anaphylaxis. In this study, we detected IgE-binding epitopes within the primary sequence of -5 gliadin using arrays of overlapping peptides synthesized on derivatized cellulose membranes. Sera from four patients with WDEIA having specific IgE to the fast -gliadin were used to probe the membrane. Seven epitopes, QQIPQQQ, QQLPQQQ, QQFPQQQ, QQSPEQQ, QQSPQQQ, QQYPQQQ, and PYPP, were detected within the primary sequence of -5 gliadin. By using sera of 15 patients, 4 of them, QQIPQQQ, QQFPQQQ, QQSPEQQ, and QQSPQQQ, were found to be dominant epitopes. Mutational analysis of the QQIPQQQ and QQFPQQQ indicated that amino acids at positions Gln 1 , Pro 4 , Gln 5 , Gln 6 , and Gln 7 were critical for IgE binding. These results will provide a useful tool for developing safer wheat products in addition to diagnostic and immunotherapy techniques for WDEIA.Food-dependent exercise-induced anaphylaxis is a distinct form of food allergy induced by physical exercise (1). Food items such as shrimp (2), hazelnut (3), buckwheat (4), corn (5), and celery (6) are responsible for the development of food-dependent exercise-induced anaphylaxis. However, of all of the various kinds of food, wheat is reported to be the allergen with the highest frequency in Japan (7). Symptoms are typically generalized urticaria and severe allergic reactions such as shock or hypotension. Because of this serious reaction, it is important to determine the causative food to avoid the allergic reaction. A challenge test consisting of ingestion of the assumed food followed by intense physical exercise is the only reliable method to determine the causative food and to diagnose the disease. However, the challenge test is not always safe because in some cases the test induces an anaphylactic shock. In addition, the most reliable treatment for this disease is to avoid taking the causative food or, alternatively, to take a rest after meals. However, in the case of wheat allergy, elimination causes a decline in the quality of life for the patients. Thus, an in vitro diagnostic method as well as hypoallergenic wheat is necessary for patients with wheat-dependent exercise-induced anaphylaxis (WDEIA). 1Recent studies have revealed the IgE-binding epitopes of several food allergens including egg (8), milk (9, 10), soybean (11), and peanut (12), whereas the IgE-binding epitopes for wheat allergen are controversial. Wheat protein is composed of water/salt-soluble proteins and water/salt-insoluble proteins. Proteins in the water/salt-soluble fraction, such as ␣-amylase inhibitor, peroxidase, glycerinaldehyde-3-phosphate dehydrogenase, serpin, and triosephosphate isomerase, have been considered to be major allergens in patients with bakers' asthma (13-15...

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.

SUMMARYBD is prevalent in the area of the Silk Route. It has been shown that hsp are involved in the T cell activation in patients with BD in the UK, where this disease has developed sporadically. We have thus examined whether the T cell response to the hsp-derived peptides may be induced in patients with BD in Japan, an east pole of the Silk Route. As with patients in the UK, the human 60-kD hsp peptide 336-351 also yielded vigorous proliferation of T cells in Japanese patients with BD, but neither in normal subjects nor in patients with rheumatoid arthritis (RA); there was significant association between proliferation by this peptide and the presence of ocular lesion, but not any other symptoms of BD. To clarify whether the peptide stimulates T cells as a polyclonal activator, a specific antigen or a superantigen-like substance, we analysed T cell receptor (TCR) usage of responding T cells by means of MoAbs specific for TCR Vb subfamily and polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP)-based technique. We found that T cells with certain TCR Vb subfamilies (including Vb5.2-3, 8, 13.6, 18, 21.3) were increased in circulation and responded to the hsp peptide in an antigen-specific fashion. In addition, TCR Vb gene-amplified products of freshly isolated T cells of patients with BD formed several bands in the PCR-SSCP analysis; some of them became prominent after stimulation with the peptide. This suggests that T cells in patients with this disease have already been expanded oligoclonally in vivo, which may be a result of stimulation by triggering antigens, including the hsp peptide. In addition, hsp peptide stimulation induced proinflammatory cytokine mRNA expression in peripheral blood mononuclear cells, including IL-8, tumour necrosis factor-alpha (TNF-a) and TNF-b in eight out of eight patients studied. Taken together, the results suggest that hsp antigen may play a role in the pathogenesis of BD, not only in the area of the Silk Route, but also outside the Silk Route area.

Phenotypic and functional properties of γδ T cells, which play an important role in mucocutaneous immunity, were examined to elucidate whether immunological abnormality in Behc¸et's disease may be related to a specific T cell population. We found that CD45RA+Vγ9+Vδ2+γδ T cells, which constitute a minor population of γδ T cells in healthy individuals, were increased in number in Behc¸et's disease irrespective of disease activity. This CD45RA+ subset of γδ T cells in the active, but not inactive, phase of this disease expressed IL‐2Rβ and HLA‐DR, suggesting that they are activated in vivo in active Behc¸et's disease. In addition, the CD45RA+γδ T cells produced extreme amounts of tumour necrosis factor and contained perforin granules. These data indicate that a phenotypically distinct subset of γδ T cells, CD45RA+CD45RO−Vγ9+Vδ2+, may contribute to immunological abnormalities which may lead to complexity of pathophysiology in Behc¸et's disease.