Study of pulmonary (lung) functioning of commercial wheat grinding machine operators in India using spirometric testing

In ancient times, in India each household had a chakki to mill the wheat. There was no concept of getting wheat grounded from outside. With the fast changing lifestyle, this tradition has almost disappeared now. Today every city of India has numerous commercial wheat grinding machine shops located at various places. Other than states like Punjab, this occupation is mostly unorganized and little has been done to look into the welfare and health of these machine operators. Like most of the occupations, this occupation of wheat grinding also has several occupational hazards and injuries associated with it. The most obvious of them all in this case is due to the continuous exposure of the operators to the rising dust wheat particles, commonly called atta). This perpetual inhaling ofpollutants exposes the operators to risks of pulmonary malfunctioning. Therefore, this paper attempts to determine the pulmonary functioning of the commercial wheat grinding machine operators in India using spirometric testing. On the basis of the anthropometric data, effort has been done to develop the expected lung performance. Further, the actual lung performance of the operators is measured and compared with expected performance.

Usefulness of wheat and soybean specific IgE antibody titers for the diagnosis of food allergy

BACKGROUND

Since the first suggestion of threshold values for food specific IgE antibody levels in relation to clinical reactivity, several authors have proposed different threshold values for different allergens. We investigated the relationship between wheat/soybean specific IgE antibody levels and the outcome of wheat/soybean allergy diagnosis in children of different ages.

METHODS

A retrospective study was conducted in 536 children admitted consecutively to our clinic with the suspicion of wheat and/or soybean allergy. The children underwent an oral food challenge and blood samples for specific IgE measurement were obtained.

RESULTS

The children who reacted to the oral food challenge had higher specific IgE titers to the specific allergen compared to the non-reacting group. The risk for reaction increased 2.33-fold (95% CI 1.90-2.87) for wheat and 2.08-fold (95% CI 1.65-2.61) for soybean, with increasing levels of specific IgE. A significant difference between the ages of subjects pertained only to wheat.

CONCLUSIONS

We found a relationship between the probability of failed challenge and the concentration of IgE antibodies to both wheat and soybean. Age influences the relationship of allergen specific IgE levels to wheat and oral food challenge outcome. Younger children are more likely to react to low levels of specific IgE antibody concentration to wheat than older children.

Wheat grain allergies: an update on wheat allergens

Wheat grain is a major staple of our diet. However, proteins derived from wheat grain have been implicated in both respiratory and food allergies, as well as in contact hypersensitivity. Numerous wheat allergens are present in the different fractions of wheat grain: a-amylase/trypsin inhibitor and lipid transfer protein are found in the water/salt soluble fraction, and omega5-gliadins and LMW-glutenins have been detected in the gluten fraction. This review discusses what is currently known about wheat grain proteins and allergens. The type of IgE-binding profiles (allergens or even epitopes) in patients with wheat food allergy as a function of age, symptoms, or genetic variability of wheat cultivars provides interesting and useful data for developing hypoallergenic foods as well as new tools for diagnostic and therapeutic methods.

Prediction of challenge test results by flour-specific IgE and skin prick test in symptomatic bakers

BACKGROUND

Wheat and rye flours are among the most important allergens causing occupational asthma. Usually, the diagnosis of baker's asthma is based on inhalation challenge tests with flours.

AIMS OF THE STUDY

To evaluate the relevance of flour-specific serum immunoglobulin E (IgE) and skin prick test (SPT) in the diagnosis of baker's asthma and to define flour-specific IgE concentrations and wheal sizes that allow a prediction of the outcome of challenge testing.

METHODS

Bronchial and nasal challenge tests with wheat (rye) flour were performed in 71 (95) symptomatic bakers. Determinations of flour-specific IgE as well as SPTs were performed in all subjects. Analyses included the calculation of sensitivity, specificity, positive (PPV) and negative predictive values (NPV) at different IgE concentrations and different wheal sizes, and receiver-operating characteristics (ROC) plots with the challenge result as gold standard.

RESULTS

Thirty-seven bakers were positive in the challenge with wheat flour, while 63 were positive with rye flour. Depending on the flour-specific IgE concentrations (wheal size), PPV was 74-100% (74-100%) for wheat and 82-100% (91-100%) for rye flour, respectively. The minimal cut-off values with a PPV of 100% were 2.32 kU/l (5.0 mm) for wheat flour and 9.64 kU/l (4.5 mm) for rye flour. The shapes of the ROC plots were similar for wheat and rye flour.

CONCLUSION

High concentrations of flour-specific IgE and clear SPT results in symptomatic bakers are good predictors for a positive challenge test. Challenge tests with flours may be avoided in strongly sensitized bakers.

Celiac disease: in vitro and in vivo safety and palatability of wheat-free sorghum food products

BACKGROUND & AIMS

Celiac disease is a condition in which genetically predisposed people have an autoimmune reaction to gluten proteins found in all wheat types and closely related cereals such as barley and rye. This reaction causes the formation of autoantibodies and the destruction of the villi in the small intestine, which results in malabsorption of nutrientsand other gluten-induced autoimmune diseases. Sorghum is a cereal grain with potential to be developed into an important crop for human food products. The flour produced from white sorghum hybrids is light in color and has a bland, neutral taste that does not impart unusual colors or flavors to food products. These attributes make it desirable for use in wheat-free food products. While sorghum is considered as a safe food for celiac patients, primarily due to its relationship to maize, no direct testing has been conducted on its safety for gluten intolerance. Therefore studies are needed to assess its safety and tolerability in celiac patients. Thus the aim of the present study was to assess safety and tolerability of sorghum flour products in adult celiac disease patients, utilizing an in vitro and in vivo challenge.

RESULTS

Sorghum protein digests did not elicit any morphometric or immunomediated alteration of duodenal explants from celiac patients. Patients fed daily for 5 days with sorghum-derived food product did not experience gastrointestinal or non-gastrointestinal symptoms and the level of anti-transglutaminase antibodies was unmodified at the end of the 5-days challenge.

CONCLUSIONS

Sorghum-derived products did not show toxicity for celiac patients in both in vitro and in vivo challenge. Therefore sorghum can be considered safe for people with celiac disease.

Genetic differences in omega-gliadins involved in two different immediate food hypersensitivities to wheat

BACKGROUND

Anti-gliadin IgE are expressed in patients with food allergy associated to skin immediate hypersensitivity to hydrolyzed wheat proteins (IHHWP). It is not known if they react with omega5-gliadins, the major allergens in wheat dependant exercise-induced food anaphylaxis (WDEIA), encoded on wheat chromosomes 1B.

METHODS

Unmodified gliadins from 14 wheat varieties expressing most of the 1B omega-gliadin alleles, were immunoprobed after SDS-PAGE and blotting, with four sera from patients with IHHWP, and two with WDEIA. Gliadins reacting with IgE were visualized using chemiluminescence and identified according to their mobility and typical SDS-PAGE pattern. The resulting signal was also measured to compare their IgE reactivity.

RESULTS

IHHWP and WDEIA sera exhibited distinct patterns of reactivity. IgE of patients with IHHWP reacted mainly with all omega-gliadins alleles and one gamma-gliadin encoded respectively on chromosomes 1D and 1B, but not with any omega5-gliadins alleles as for WDEIA. A few other reactive alleles of omega-gliadins were encoded on chromosomes 1A. Unassigned additional bands of the whole gliadin pattern were also reactive. The four patients with IHHWP exhibited almost the same pattern of reactivity. Main differences concerned band reactivity which modulated the overall reactivity of each wheat variety.

CONCLUSIONS

The IgE epitopes involved in IHHWP and WDEIA are different. This suggests that the protein state and the route of exposure to very similar gluten structures, probably orientate the pattern of epitope reactivity and the wheat food allergy manifestations.

Oral specific desensitization in food-allergic children

The possibility of obtaining oral desensitization in patients with food allergy is still a matter of debate. We decided to evaluate the safety and efficacy of standardized protocols for oral desensitization with the most common food allergens. Forty-two children (ages up to 16 years) diagnosed as affected by food allergy (on the basis of clinical history, skin prick tests, measurement of specific IgE, and double-blind, placebo-controlled food challenge) underwent a sublingual-oral desensitizing treatment according to new standardized protocols. The control group consisted of 10 patients who followed an elimination diet. The treatment was successfully completed by 85.7% of the patients. Specific IgE showed a significant decrease, while specific IgG(4) showed a significant increase, in all treated patients. The immunological modifications observed in our patients lead us to hypothesize that oral tolerance may be mediated by the same mechanisms as those involved in traditional desensitizing treatments for respiratory and insect sting allergy.

Allergic contact dermatitis to hydrolyzed wheat protein in a cosmetic cream

Hydrolyzed wheat protein is used as an additive in several cosmetic products. We present a case of contact allergy to hydrolyzed wheat protein found in a cosmetic cream and highlight this additive is a potential allergen.

[Animal nutrition for veterinarians--case study: colic in ponies in a "petting zoo" caused by ingestion of higher amounts of wheat (Triticum aestivum L.)]

Nutritional disorders in domestic or pet animals depend not seldom on special situations, for example when different influences coincide concerning keeping, housing and offering of feed or water. These lead suddenly to high-risk situations, that can cause sometimes the death of the animal. The following case report deals with two ponies, that were kept on a so-called "petting zoo" and showed repeatedly colic symptoms (always after a weekend). During surgery in the stomach light yellow balls were found, that can be explained by ingestion of 1.0 to 1.5 kg wheat. This cereals consist--depending on variety--gluten, that can cause the observed conglobates. Due to the forming of such balls that can lead to health disorders in form of colics, gastritis or ruptures of the stomach the feeding of high amounts of wheat should be avoided. Snacks rich in fiber or high amounts of roughage (straw, hay) that are fed before opening of the zoo could be a practical alternative.

Hydrolysed wheat proteins present in cosmetics can induce immediate hypersensitivities

Cosmetics containing hydrolysed wheat proteins (HWP) can induce rare but severe allergic reactions. 9 patients, all females without common wheat allergy, but with contact urticaria to such cosmetics, were studied. 6 of them also experienced generalized urticaria or anaphylaxis to foods containing HWP. All patients had low to moderate levels of immunoglobulin (Ig)E specific of wheat flour (f4) or gluten (f79). Their sensitivity to HWP and their tolerance to unmodified wheat proteins extracted from grains were confirmed using skin tests. Immunoblotting analyses showed that IgE from all patients reacted with almost all HWP tested. Reactions generally occurred with large random peptide aggregates. IgE reacted also with unmodified grain proteins, which contrasted with skin tests results. They reacted always with salt soluble proteins but variably with gluten proteins. No reaction occurred with gliadins in patients without associated immediate hypersensitivity to food containing HWP. These results show the role of hydrolysis on the allergenicity of wheat proteins, both through skin or digestive routes. At least part of the epitopes involved is pre-existing in unmodified wheat proteins. The aggregation of peptide bearing these epitopes and others created by hydrolysis, along with the increased solubility and the route of exposure, are possible factors of the allergenicity of HWP.

[Determination of the tryptase level as diagnostic marker in food allergy in children]

BACKGROUND

during food provocation the mast cell degranulates causing the elevation of serum tryptase.

AIM OF STUDY

the aim of our work was to estimate if tryptase level is the efficient diagnostic marker in case of IgE dependent food allergy in children.

MATERIAL AND METHODS

the studied group (group I) consisted of 100 children (age 3-5 yrs) with IgE dependent food allergy confirmed by positive case history and allergy tests. The children presented an allergic reaction to one of the 3 most common food allergens - milk, egg and wheat flour proteins. Control group (group II) consisted of 31 healthy children. The open food provocation was performed only in the group I. Tryptase level was estimated before and 120 minutes after the food provocation. The FluoroEnzymeImmunoAssay method (FEIA) was used to assess the tryptase levels.

RESULTS

baseline level of the tryptase in group I was significantly higher in comparison with group II. There was no significant difference between baseline level of the tryptase and level after the provocation. The decrease of the level of the tryptase after challenge was observed in 54% patients in group I. The increase of the tryptase level after the provocation was observed in 45% patients and in 1% patients the level of the tryptase was unchanged.

CONCLUSIONS

1. tryptase levels are not an effective marker in diagnostic of IgE dependent food allergy in children with allergic reaction to one or more food allergens, 2. patients with IgE dependent food allergy may have elevated level of tryptase with no clinical manifestation.

Wheat allergy: a double-blind, placebo-controlled study in adults

BACKGROUND

Wheat is believed to be an uncommon cause of food allergy in adults; the number of studies that address IgE mediated wheat allergy in adults is all too few.

OBJECTIVE

Determine how many subjects with a history of wheat allergy have real allergy by double-blind, placebo-controlled food challenge; identify the symptoms manifested during the challenge; determine the lowest provocation dose; determine the performance characteristics of wheat skin prick test and specific IgE; identify subjects with real wheat allergy for potential immunoblotting studies.

METHODS

Patients underwent skin test with commercial wheat extract; specific wheat IgE was determined. Subjects were challenged with 25 g wheat. Subjects who were positive to raw wheat challenge underwent cooked wheat challenge.

RESULTS

Thirty-seven double-blind placebo-controlled wheat challenges were performed on 27 patients. A total of 13 of 27 (48%) patients had a positive result. Eleven subjects with positive raw wheat challenge underwent cooked wheat challenge: 10 were positive. The provocation dose range was 0.1 to 25 g. Twenty-seven percent of the subjects allergic to wheat had a provocation dose that was < or =1.6 g.

CONCLUSION

Wheat causes real food allergy in adults. More than a quarter of the patients allergic to wheat reacted to less than 1.6 g wheat. Specific IgE was more sensitive than skin test for wheat; however, specificity and predictive values were low for both tests. Thus, these tests should not be used to validate diagnosis of wheat allergy.

Wheat flour allergy: an entire diagnostic tool for complex allergy

Wheat proteins are involved in respiratory allergy, contact allergy and food allergy. Wheat allergens involve in these pathologies are well-known. However, establishment of wheat allergy diagnostic can be sometimes difficult on account of the complex allergenic composition of skin prick test (SPT) solutions of wheat flour. Therefore, we have studied specific IgE reactivity from patient sera with wheat food allergy, and characterized allergenic composition of wheat SPT solutions by specific antibodies directed to wheat allergens. The results showed that 20 of the 25 sera analyzed contained specific IgE to at least one wheat protein fraction. Among positive sera, 75% have specific IgE to water/salt soluble fraction, 85% to native gluten fractions and 65% to wheat isolate fraction. The results showed also that SPT solutions of wheat flour contained major food allergens from each allergenic fraction. These results highlighted the importance of using fractions, which constitute the whole wheat allergenic pattern, during specific IgE reactivity analyses. Moreover, we have observed that wheat isolate extract (results of food industrial process) contained not only modified allergens (neo-allergens) involve of specific food allergy to wheat isolate but also some native allergens involve in wheat food allergy. Thus, these results showed the importance to use, for wheat in vivo diagnosis together wheat SPT solutions (gluten extract and wheat isolate) in order to differentiate wheat food allergy to specific wheat isolate allergy.

Wheat and maize thioredoxins: a novel cross-reactive cereal allergen family related to baker's asthma

BACKGROUND

Baker's asthma is a serious problem for a significant proportion of workers in bakeries, confectionaries, and the food industry. Although several wheat allergens related to baker's asthma have been described, standardized reagents for a reliable diagnosis are not yet available.

OBJECTIVE

To clone novel wheat allergens related to baker's asthma and investigate the cross-reactive potential of their maize and human homologues.

METHODS

A wheat cDNA phage display library was screened with sera from bakers with occupational asthma for IgE-binding structures. Homologous sequences from maize and human thioredoxins were amplified from corresponding cDNA libraries.

RESULTS

Within the enriched wheat cDNA repertoire we identified, among others, the sequence encoding wheat thioredoxin-hB (Triticum aestivum allergen 25 [Tri a 25]). The recombinant protein displayed enzymatic activity, and we observed a sensitization rate of 47% among bakers with occupational asthma and of 35% among patients with grass pollen allergy, but without a clinical history of cereal allergy. Furthermore, the previously characterized maize thioredoxin-h1 (Zea mays allergen 25 [Zea m 25]), sharing 74% identity with Tri a 25, exhibited distinct IgE cross-reactivity with its wheat homologue. Two bakers also showed sensitization to human thioredoxin, which shares 29% identity with Tri a 25. In a comparative study, we included recombinant alpha-amylase inhibitor 0.19, showing a sensitization rate of 65% in individuals with baker's asthma.

CONCLUSION

Thioredoxins represent a novel family of cross-reactive allergens that might contribute to the symptoms of baker's asthma and might in addition be related to grass pollen allergy, as indicated by the reactivity of grass pollen allergic patients to cereal thioredoxins.

CLINICAL IMPLICATIONS

The recombinant cereal thioredoxins will, together with the already reported wheat allergens, contribute to a more reliable diagnosis of baker's asthma and, perhaps, become a tool for the development of component-resolved immunotherapy.

Treatment of eosinophilic esophagitis with specific food elimination diet directed by a combination of skin prick and patch tests

BACKGROUND

Eosinophilic esophagitis (EE) is a recently described disorder identified in patients with symptoms suggestive of gastroesophageal reflux disease (GERD) but unresponsive to conventional reflux therapies. Therapies have included corticosteroids, elemental diet, and diet restriction. We report our experience with skin prick and atopy patch testing and food elimination diets in patients diagnosed as having EE.

OBJECTIVE

To identify food antigens that cause EE and the characteristics of patients who respond to food elimination vs those who are unresponsive.

METHODS

Patients diagnosed as having EE had restricted diets based on skin prick and atopy patch testing results. Additional biopsies were performed after 4 to 8 weeks of restricted diet. Demographics, atopic tendencies, and food antigens were identified retrospectively in our food allergy database.

RESULTS

A total of 146 patients diagnosed as having EE were evaluated with skin prick and atopy patch testing. Thirty-nine patients had unequivocal demonstration of food causing EE, with normalization of biopsy results on elimination and reoccurrence on reintroduction. An additional 73 patients, for a total 112 (77%) of 146 patients, had resolution of their EE as demonstrated by biopsy results. Fifteen (10%) of 146 patients were nonresponders manifested by no significant reduction in esophageal eosinophils despite restricted diet based on skin prick and atopy patch testing. Egg, milk, and soy were identified most frequently with skin prick testing, whereas corn, soy, and wheat were identified most frequently with atopy patch testing.

CONCLUSION

In more than 75% of patients with EE, both symptoms and esophageal inflammation can be significantly improved with dietary elimination of foods. Skin prick and atopy patch testing can help identify foods in most patients.

Food induced urticaria in children

We conducted a prospective study at King Chulalongkorn Memorial Hospital, from June 2001 to November 2003, to identify the contribution of food allergy to urticaria in children. During the study period, 100 children with urticaria were enrolled, 36 of whom had a history suspicious of food allergy. Fifteen of 100 patients had fever (9 from upper respiratory tract infections, 4 from diarrhea and 2 from skin infections). A skin prick test (SPT) was positive in 15 of the 36 children who were suspected of having food allergy; 5 patients out of the positive SPT group had anaphylaxis due to food (2 from cow milk, 2 from wheat and 1 from egg). Six patients in the positive SPT group had a negative food challenge test (4 from open challenges and 2 from double-blind placebo-controlled food challenges [DBPCFC]). The other 4 patients of the positive SPT group refused the food challenge test. The parents of a patient who had urticaria from egg refused the skin prick test; an oral challenge test confirmed the diagnosis of egg allergy. One of the 21 patients that had a negative SPT had shrimp allergy proven by DBPCFC. Of the 64 patients who had no history related to food, SPT was done in 27 patients and revealed a positive result in 7 patients, all of whom had a negative food challenge test (4 with open challenge and 3 with DBPCFC). Urticaria from food was found in 7% and was suspected in another 4% of the patients. Severe reactions to food like anaphylaxis may occur. SPT alone is not adequate in making the diagnosis of food allergy; it must be confirmed by a food challenge test. Thirty percent of patients that did not have a history related to food had false positive SPT. Without a history suspicious of food allergy, SPT yields only minimal benefit.

Transglutaminases: a meeting point for wheat allergy, celiac disease, and food safety

Wheat is the staple cereal in many countries and its uses in manufactured foods are ever growing due to the technological qualities of gluten proteins. Transglutaminases (TG) are ubiquitous enzymes with many functions. They are able to transform proteins by deamidation and/or transamidation. This last reaction can cross-link proteins together. Intestinal tissue TG has been shown to play an important role in two kinds of immune reactions to wheat: celiac disease and wheat-dependent exercise-induced anaphylaxis. In addition, new epitopes have been suspected in cases of anaphylaxis to wheat isolates, a food ingredient consisting mainly of deamidated gluten proteins. As a microbial TG is included in many food technological processes, its safe use should be checked. This assessment must cover not only the safety of the TG itself but also that of the deamidated/cross-linked proteins generated by this enzyme. This article aims at discussing the possible consequences of using TG in food industry in the light of today knowledge about immune reactions to wheat.

Utility of the ratio of food-specific IgE/total IgE in predicting symptomatic food allergy in children

BACKGROUND

Double-blind, placebo-controlled food challenges are time-consuming, expensive and not without risk to patients. Therefore, an in vitro test that could accurately diagnose food allergy would be of great value.

OBJECTIVE

To evaluate the utility of the ratio of specific immunoglobulin E (IgE)/total IgE compared with specific IgE (sIgE) alone in predicting symptomatic food allergy.

METHODS

We retrospectively analysed 992 controlled oral food challenges performed in 501 children (median age 13 months). The ratio of sIgE/total IgE was calculated and tested for correlation with the outcome of food challenges. Receiver operator characteristics (ROC)-curves were performed; predicted probabilities and predictive decision points were calculated.

RESULTS

A significant correlation was found between the ratio and the outcome of food challenges for cow's milk (CM), hen's egg (HE), and wheat, but not for soy. The ROC and predicted probability curves as well as sensitivity and specificity of the decision points of the ratio were similar to those of sIgE levels for CM, HE and wheat.

CONCLUSION

In view of the greater effort needed to determine the ratio, without benefit compared with the sIgE alone, the calculation of the ratio of sIgE/total IgE for diagnosing symptomatic food allergy offers no advantage for CM, HE, wheat or soy. For the majority of cases controlled oral food challenges still remain the method of choice.

A Kansas wheat harvest: near-fatal asphyxiation with wheat grains

We present a patient who had a near-fatal asphyxiation with wheat particles. A previously healthy 11-year-old boy slipped into wheat being unloaded from a transport wagon and was immediately submersed. On arrival at the hospital, he was found to have grain impacted in both mainstem bronchi. A combination of flexible and rigid bronchoscopy with optical forceps and Fogarty balloon catheters was successful in clearing the airways. The removal of the particles through the use of small bronchoscopic instruments is a tedious and delicate procedure, but in this case, it resulted in a life saved.

Exercise and aspirin increase levels of circulating gliadin peptides in patients with wheat-dependent exercise-induced anaphylaxis

BACKGROUND

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.

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Identification of IgE-binding epitopes on gliadins for patients with food allergy to wheat

BACKGROUND

Food allergy to wheat induces different symptoms as atopic eczema/dermatitis syndrome (AEDS), urticaria and more severe reactions as wheat-dependent exercise-induced anaphylaxis (WDEIA). Different gliadin classes are involved in this allergy but IgE-binding epitopes are known only on omega5-gliadins and for WDEIA cases.

OBJECTIVES

The aim of the study was to identify IgE-binding epitopes on several gliadin classes and for several patients with different symptoms and ages.

METHODS

Eleven sera were analysed by pepscan with overlapping synthetic peptides.

RESULTS

Sera from five patients with anaphylaxis, urticaria or WDEIA, displayed strong IgE-binding to sequential epitopes of the repetitive domains of alphabeta, gamma, omega2 or omega5-gliadins with two immunodominant epitopes on omega5-gliadin and a consensus motif of the type QQX1PX2QQ (X1 being L, F, S or I and X2 Q, E or G). One patient allergic to deamidated wheat proteins also had IgE to a repetitive peptide of gamma and omega2-gliadins of the type QPQQPFP. Sera from four patients with AEDS detected no linear epitopes on gliadins, despite the fact that they contained specific IgE to alpha, beta, gamma or omega-gliadins. One child with AEDS recognized cysteine-containing sequences in the nonrepetitive domains of alphabeta and gamma-gliadins.

CONCLUSION

B epitopes in wheat allergy were different from B epitopes of coeliac disease. Differences exist in IgE-binding epitopes between patients with food allergy to wheat. IgE from those suffering from WDEIA, anaphylaxis and urticaria detected sequential epitopes in the repetitive domain of gliadins whereas IgE from AEDS patients probably recognized conformational epitopes.