Glucose/Ribitol Dehydrogenase and 16.9 kDa Class I Heat Shock Protein 1 as Novel Wheat Allergens in Baker's Respiratory Allergy.

Wheat allergens are responsible for symptoms in 60-70% of bakers with work-related allergy, and knowledge, at the molecular level, of this disorder is progressively accumulating. The aim of the present study is to investigate the panel of wheat IgE positivity in allergic Italian bakers, evaluating a possible contribution of novel wheat allergens included in the water/salt soluble fraction. The water/salt-soluble wheat flour proteins from the Italian wheat cultivar Bolero were separated by using 1-DE and 2-DE gel electrophoresis. IgE-binding proteins were detected using the pooled sera of 26 wheat allergic bakers by immunoblotting and directly recognized in Coomassie stained gel. After a preparative electrophoretic step, two enriched fractions were furtherly separated in 2-DE allowing for detection, by Coomassie, of three different proteins in the range of 21-27 kDa that were recognized by the pooled baker's IgE. Recovered spots were analyzed by nanoHPLC Chip tandem mass spectrometry (MS/MS). The immunodetected spots in 2D were subjected to mass spectrometry (MS) analysis identifying two new allergenic proteins: a glucose/ribitol dehydrogenase and a 16.9 kDa class I heat shock protein 1. Mass spectrometer testing of flour proteins of the wheat cultivars utilized by allergic bakers improves the identification of until now unknown occupational wheat allergens.

Food Protein-Induced Enterocolitis Syndrome in Children with Down Syndrome: A Pilot Case-Control Study.

Food protein-induced enterocolitis syndrome (FPIES) is a non-immunoglobin E-mediated food hypersensitivity disorder. However, little is known about the clinical features of FPIES in patients with Down syndrome (DS). Medical records of children with DS diagnosed at our hospital between 2000 and 2019 were retrospectively reviewed. Among the 43 children with DS, five (11.6%) were diagnosed with FPIES; all cases were severe. In the FPIES group, the median age at onset and tolerance was 84 days and 37.5 months, respectively. Causative foods were cow's milk formula and wheat. The surgical history of colostomy was significantly higher in the FPIES group than in the non-FPIES group. A colostomy was performed in two children in the FPIES group, both of whom had the most severe symptoms of FPIES, including severe dehydration and metabolic acidosis. The surgical history of colostomy and postoperative nutrition of formula milk feeding may have led to the onset of FPIES. Therefore, an amino acid-based formula should be considered for children who undergo gastrointestinal surgeries, especially colostomy in neonates or early infants. When an acute gastrointestinal disease is suspected in children with DS, FPIES should be considered. This may prevent unnecessary tests and invasive treatments.

Detection of Wheat Lipid Transfer Protein (Tri a 14) Sensitization: Comparison between Currently Available Diagnostic Tools.

BACKGROUND: Wheat lipid transfer protein (LTP; Tri a 14) and ω5-gliadin have been described as major allergens in wheat allergy (WA) and relevant in wheat-induced anaphylaxis, frequently associated with cofactors. OBJECTIVE: The objective of this study was to compare tools currently available in routine diagnosis to detect Tri a 14 sensitization, its clinical relevance, and cosensitization to ω5-gliadin and other LTPs. METHODS: One hundred eighteen adults sensitized to rTri a 14 by ImmunoCAP® (cutoff ≥0.1 kUA/L) identified among 210 LTP allergic patients were included. We evaluated (1) wheat skin prick test (SPT), (2) specific IgE (sIgE) to wheat, rTri a 14, rTri a 19, peach, apple, walnut, hazelnut, and peanut LTPs using ImmunoCAP® and microarray ImmunoCAP®ISAC (cutoff ≥0.3I SU), and (3) wheat-related symptoms. RESULTS: Wheat SPT and sIgE were positive in 31% and 85% of subjects, respectively. rTri a 14 by microarray was detected in 25%. Eight percent showed cosensitization to ω5-gliadin. Thirty percent referred symptoms (gastrointestinal [13%], urticaria [11%], and anaphylaxis [8%]). Cofactors (45%) were significantly associated with systemic reactions. CONCLUSION: WA due to Tri a 14 is frequently related with systemic reactions and because are frequently related to cofactors, the culprit may not be suspected. Together with the poor performance to identify Tri a 14 sensitization of the current routine diagnostic tools based on the analysis of whole wheat extract, such as wheat SPT or sIgE, there is a high risk that WA may be overlooked. Thus, when WA is suspected, sIgE Tri a 14 assessment is recommended, together with wheat and ω5-gliadin, preferably in the singleplex format, and carefully evaluated considering ≥0.1 kUA/L as a cutoff.

Oral food challenge in IgE mediated food allergy in eastern Mediterranean children.

BACKGROUND: The oral food challenge (OFC) in IgE mediated food allergy causes anxiety both in parents and in patients due to its inherent risks. OBJECTIVE: Documentation of the rate, spectrum, and predictors of positive reactions is instructive. METHODS: Children, who underwent OFC between January 1, 2017 and December 31, 2019 were analyzed. RESULTS: A total of 1361 OFCs in 613 cases were reviewed. Most of them were performed in preschool children (≤2 years 50%) and 55% of them had more than one OFC. Mainly considered food groups were cow's milk (31.8%), hen's egg (28.5%), tree nuts (20%), legumes (7%), seeds (4.9%), and wheat (2.7%). The overall OFC positivity was 9.6%, whereas 6.7% with cow's milk, 4.9% with hen's egg, 16.1% with tree nuts, 21.6% with wheat, and 32.8% with seeds. The severity scoring revealed grade I (24.4%), II (45.8%), and III (29.7%) reactions. Fifty (38%) cases required epinephrine and four cases required hospitalization. OFCs with sesame seeds (odds ratio [OR]: 7.747, [confidence interval (CI) 95%: 4.03-14.90]), wheat (OR: 3.80, [CI: 1.64-8.84]), and tree nuts (OR: 2.78, [CI: 1.83-4.23]) predicted a positive OFC while a concomitant asthma (OR: 3.61 [CI: 1.27-10.28]) was more likely to elicit anaphylaxis. CONCLUSION: In OFC practice, priority is given to basic nutritional sources and the most frequent food allergens, where preschool children with multiple sensitizations are the primary subjects. Increased risks of positive reactions with sesame, tree nut, and wheat and increased risk of anaphylaxis with concomitant asthma should be considered while performing OFC.

Non-Celiac Gluten/Wheat Sensitivity: Clinical Characteristics and Microbiota and Mycobiota Composition by Response to the Gluten Challenge Test.

The aims of this observational "proof-of-concept" study were to analyze the clinical/psychological characteristics and gut microbiota/mycobiota composition of individuals with suspected non-celiac gluten/wheat sensitivity (NCGS/WS) according to responses to the double-blind-placebo-controlled (DBPC) crossover gluten challenge test. Fifty individuals with suspected NCGS/WS were subjected to the DBPC challenge test; anthropometric measurements, psychometric questionnaires, and fecal samples were collected. Twenty-seven (54%) participants were gluten responsive (NCGS), and 23 were placebo responsive, with an order effect. NCGS individuals displayed a significantly lower risk of eating disorders and a higher mental health score when compared to placebo-responsive participants, confirmed by multiple logistic regression analyses (OR = 0.87; 95% CI 0.76-0.98, p = 0.021, and OR = 1.30; 95% CI 1.06-1.59, p = 0.009, respectively). Principal coordinate analyses based on microbiota composition showed a separation by the DBPC response (p = 0.039). For Bacteroides (p = 0.05) and Parabacteroides (p = 0.007), the frequency of amplicon sequence variants was lower, and that for Blautia (p = 0.009) and Streptococcus (p = 0.004) was higher in NCGS individuals at multiple regression analyses. No difference in the mycobiota composition was detected between the groups. In conclusion, almost half of the individuals with suspected gluten sensitivity reported symptoms with placebo; they showed lower mental health scores, increased risk for eating disorders, and a different gut microbiota composition.

Food protein-induced enterocolitis syndrome oral food challenge: Time for a change?

OBJECTIVE: Food protein-induced enterocolitis syndrome (FPIES) is typically diagnosed based on a characteristic clinical history; however, an oral food challenge (OFC) may be necessary to confirm the diagnosis or evaluate for the development of tolerance. FPIES OFC methods vary globally, and there is no universally agreed upon protocol. The objective of this review is to summarize reported FPIES OFC approaches and consider unmet needs in diagnosing and managing FPIES. DATA SOURCES: PubMed database was searched using the keywords food protein-induced enterocolitis syndrome, oral food challenge, cow milk allergy, food allergy, non-immunoglobulin E-mediated food allergy and FPIES. STUDY SELECTIONS: Primary and review articles were selected based on relevance to the diagnosis of FPIES and the FPIES OFC. RESULTS: We reviewed the history of FPIES and the evolution and variations in the FPIES OFC. A summary of current literature suggests that most patients with FPIES will react with 25% to 33% of a standard serving of the challenged food, there is little benefit to offering a divided dose challenge unless there is suspicion of specific immunoglobulin E to the food being challenged, reactions typically appear within 1 to 4 hours of ingestion, and reactions during OFC rarely result in emergency department or intensive care unit admission. CONCLUSION: International standardization in the FPIES OFC approach is necessary with particular attention to specific dose administration across challenged foods, timing between the patient's reaction and offered OFC to verify tolerance, patient safety considerations before the OFC, and identification of characteristics that would indicate home reintroduction is appropriate.

Identification of peroxidase-1 and beta-glucosidase as cross-reactive wheat allergens in grass pollen-related wheat allergy.

BACKGROUND: Some patients with wheat-dependent exercise-induced anaphylaxis (WDEIA) or wheat allergy showed negative ω-5 gliadin-specific IgE test and high level of grass pollen-specific IgE. It was presumed that these patients developed allergic reaction upon cross-reaction of their IgE antibodies raised against grass pollen allergens to wheat allergens. This study aimed to clarify clinical characteristics and wheat allergens of this phenotype of WDEIA/wheat allergy, which were tentatively diagnosed as grass pollen-related wheat allergy (GPWA). METHODS: A total of six patients with GPWA were enrolled, and controls were 17 patients with grass pollen allergy but no episode of wheat allergy, and 29 patients with other wheat allergies: 18 with conventional WDEIA and 11 with hydrolyzed wheat protein allergy. Sensitization to wheat proteins was determined by basophil activation test (BAT). IgE-binding proteins in wheat flour were identified by immunoblotting followed by mass spectrometry. Wheat allergen-specific IgE tests were established by CAP-FEIA system. RESULTS: All the six patients with GPWA were sensitized to water-soluble wheat proteins in BAT and IgE-immunoblotting, and peroxidase-1 (35 kDa) and beta-glucosidase (60 kDa) were identified as specific IgE-binding wheat proteins. The binding of patient IgE to these proteins was inhibited by pre-incubation of patient sera with grass pollen. The peroxidase-1- and beta-glucosidase-specific IgE tests identified three and four of six patients with GPWA, respectively, but only two of 29 controls, indicating high specificity of these tests. CONCLUSIONS: Peroxidase-1 and beta-glucosidase are specific wheat allergens for GPWA among grass pollen allergy and other types of wheat-induced food allergies.

Profiling serum antibodies with a pan allergen phage library identifies key wheat allergy epitopes.

Allergic reactions occur when IgE molecules become crosslinked by antigens such as food proteins. Here we create the 'AllerScan' programmable phage display system to characterize the binding specificities of anti-allergen IgG and IgE antibodies in serum against thousands of allergenic proteins from hundreds of organisms at peptide resolution. Using AllerScan, we identify robust anti-wheat IgE reactivities in wheat allergic individuals but not in wheat-sensitized individuals. Meanwhile, a key wheat epitope in alpha purothionin elicits dominant IgE responses among allergic patients, and frequent IgG responses among sensitized and non-allergic patients. A double-blind, placebo-controlled trial shows that alpha purothionin reactivity, among others, is strongly modulated by oral immunotherapy in tolerized individuals. AllerScan may thus serve as a high-throughput platform for unbiased analysis of anti-allergen antibody specificities.

Autoimmunity Features in Patients With Non-Celiac Wheat Sensitivity.

INTRODUCTION: Nonceliac wheat sensitivity (NCWS) is characterized by intestinal and extraintestinal manifestations consequent to wheat ingestion in subjects without celiac disease and wheat allergy. Few studies investigated the relationship between NCWS and autoimmunity. The aim of this study is to evaluate the frequency of autoimmune diseases (ADs) and autoantibodies in patients with NCWS. METHODS: Ninety-one patients (13 men and 78 women; mean age of 40.9 years) with NCWS, recruited in a single center, were included. Seventy-six healthy blood donors (HBD) and 55 patients with a diagnosis of irritable bowel syndrome (IBS) unrelated to NCWS served as controls. Autoantibodies levels were measured. Human leukocyte antigen haplotypes were determined, and duodenal histology performed in all patients carrying the DQ2/DQ8 haplotypes. Participants completed a questionnaire, and their medical records were reviewed to identify those with ADs. RESULTS: Twenty-three patients with NCWS (25.3%) presented with ADs; autoimmune thyroiditis (16 patients, 17.6%) was the most frequent. The frequency of ADs was higher in patients with NCWS than in HBD (P = 0.002) and in patients with IBS (P = 0.05). In the NCWS group, antinuclear antibodies tested positive in 71.4% vs HBD 19.7%, and vs patients with IBS 21.8% (P < 0.0001 for both). The frequency of extractable nuclear antigen antibody (ENA) positivity was significantly higher in patients with NCWS (21.9%) than in HBD (0%) and patients with IBS (3.6%) (P = 0.0001 and P = 0.004, respectively). Among the patients with NCWS, 9.9% tested positive for antithyroglobulin, 16.5% for antithyroid peroxidase, and 14.3% for antiparietal cell antibodies; frequencies were not statistically different from controls. The presence of ADs was related to older age at NCWS diagnosis, female sex, duodenal lymphocytosis, and eosinophil infiltration. DISCUSSION: One in 4 patients with NCWS suffered from AD, and serum antinuclear antibodies were positive in a very high percentage of cases. These data led us to consider NCWS to be associated to ADs.

Celiac Disease and Sensitization to Wheat, Rye, and Barley: Should We Be Concerned?

BACKGROUND: Concomitance of celiac disease (CD) and IgE-mediated wheat allergy is described in some case reports. The objective was to evaluate the frequency of sensitization to wheat, rye, barley, and malt in children and adolescents with CD. METHODS: Measurement of serum levels of specific IgE to wheat, rye, barley, and malt (ImmunoCAP; sensitization IgE ≥0.35 kUA/L) in CD patients followed in specialized clinics to verify allergy history, general characteristics, small bowel biopsy characteristics, compliance with gluten-free diet (GFD), and occurrence of symptoms in case of noncompliance. RESULTS: We evaluated 74 patients; the median of age and age at diagnosis of CD were 8.6 years (5.0-12.8) and 3.6 years (1.6-7.0), respectively. Median time of GFD was 3.5 years (1.4-5.8). History of asthma occurred in 17.3% of subjects, allergic rhinitis in 13.5%, and AD in 5.4%. Frequency of sensitization was 4% for wheat, 10.8% for rye, 5.4% for barley, and 2.7% for malt. There was no association between wheat sensitization and age at diagnosis, time of GFD, small bowel biopsy characteristics, allergy history, and gluten consumption. There was no relationship between sensitization to wheat and occurrence of immediate symptoms when not complying with GFD. CONCLUSION: In conclusion, the frequency of sensitization to wheat, rye, barley, and malt in CD patients was 4, 10.8, 5.4, and 2.7%, respectively. Therefore, to ensure that cutaneous and respiratory contact with wheat is safe, we advise patients with CD to investigate their sensitivity to wheat, rye, and barley because not all patients with CD are allergic to these cereals.

Assessment of Immune Responses in an Animal Model of Wheat Food Allergy via Epicutaneous Sensitization.

Wheat allergy is a pathological event involving immunocompetent cells against ingested wheat allergen and is clearly associated with transdermal sensitization. However, the molecular mechanisms involved in the disease etiology are not completely understood. A complex cellular and tissue network linking to food allergy makes it difficult to understand the molecular mechanism of allergenicity. Animal models are valuable tools to deduce basic principles of human disease without invasive intervention trials. A mouse model of wheat allergy has provided insights into effects of skin exposure to wheat protein; it is a plausible route of human sensitization for wheat anaphylaxis. Further investigation of this model will capture the essential occurrence and flow of events, bringing useful clues to develop effective treatment and control strategies against wheat allergy. Here, we describe a method for analyzing the expression of cell surface molecules in single cells isolated from lymphoid tissue with flow cytometry. Sensitization by wheat extracts significantly increases antigen-specific T cells in the spleen. Collecting information regarding the contribution of immune cells to allergic sensitization in the development of wheat allergy would be useful in preventing and treating food allergies.

Clinical and in vitro cross-reactivity of cereal grains in children with IgE-mediated wheat allergy

INTRODUCTION AND OBJECTIVES: Wheat and cereal grains have a broad range of cross-reactivity, but the clinical relevance of this cross-reactivity is uncertain. This study aimed to evaluate clinical and in vitro cross-reactivity with barley, oat, and Job's tears among wheat-allergic patients. MATERIALS AND METHODS: Patients aged 5 to 15 years with IgE-mediated wheat allergy were enrolled. Skin prick test (SPT) and specific IgE (sIgE) to wheat, barley, and oat, and SPT to Job's tears were performed. Oral food challenge (OFC) was conducted if the SPT was ≤5 mm in size and there was no history of anaphylaxis to each grain. Profiles of sIgE bound allergens of wheat, barley, and oat, and inhibition ELISA of IgE binding to barley and oat with wheat were performed. RESULTS: Ten patients with a median age of 8 years were enrolled. Nine of those patients had a history of wheat anaphylaxis. The median SPT size and sIgE level to wheat was 7.3 mm and 146.5 kUA/l, respectively. The cross-reactivity rate for barley, oat, and Job's tears was 60.0%, 33.3%, and 20.0%, respectively. Significantly larger SPT size and higher sIgE level were observed in patients with positive cross-reactivity to barley and oat when compared to patients without cross-reactivity. Barley and oat extracts inhibited 59% and 16% of sIgE bound to wheat gliadins and glutenins, respectively. CONCLUSION: The cross-reactivity rate was quite low for oat and Job's tears compared to that of barley; therefore, avoidance of all cereal grains may be unnecessary in patients with severe wheat allergy

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Minimal Lesions of the Small Intestinal Mucosa: More than Morphology.

Minimal lesions of the small bowel are mucosal changes characterized by an increased number of intraepithelial lymphocytes (with or without crypt hyperplasia) and normal villous architecture. Such changes are associated with a wide spectrum of conditions, ranging from food intolerances to infections, and from drugs to immune diseases, with different clinical profiles and manifestations, which complicates the formulation of a differential diagnosis. Patient history, symptom evaluation, and histopathology are the diagnostic features needed to establish a correct diagnosis. Physicians should assist pathologists in formulating a precise morphological evaluation by taking well-oriented small intestinal biopsies and collecting informative clinical findings that inform histopathology. In this current clinical controversy, the authors provide the reader with an appraisal of the small intestine minimal lesions through a careful analysis of the major conditions (e.g., celiac disease and other non-celiac disorders) responsible for such changes and their differential diagnosis. Also, we acknowledge that some of the diseases detailed in this article may progress from an early minimal lesion to overt mucosal atrophy. Thus, the timing of the diagnosis is of paramount importance.

Comparative Characterization of Gluten and Hydrolyzed Wheat Proteins.

Hydrolyzed wheat proteins (HWPs) are widely used as functional ingredients in foods and cosmetics, because of their emulsifying and foaming properties. However, in individuals suffering from celiac disease or wheat allergy, HWPs may have a modified immunoreactivity compared to native gluten due to changes in molecular structures. Although a variety of HWPs are commercially available, there are no in-depth comparative studies that characterize the relative molecular mass (Mr) distribution, solubility, and hydrophilicity/hydrophobicity of HWPs compared to native gluten. Therefore, we aimed to fill this gap by studying the above characteristics of different commercial HWP and gluten samples. Up to 100% of the peptides/proteins in the HWP were soluble in aqueous solution, compared to about 3% in native gluten. Analysis of the Mr distribution indicated that HWPs contained high percentages of low-molecular-weight peptides/proteins and also deamidated glutamine residues. We also found considerable differences between the seven HWPs studied, so that each HWP needs to be studied in detail to help explain its potential immunoreactivity.

TNF-α, IL-17, and IL-22 production in the rectal mucosa of nonceliac wheat sensitivity patients: role of adaptive immunity.

In recent years, a new gluten- or wheat-related disease has emerged, a condition labeled "nonceliac gluten sensitivity" (NCGS) or "nonceliac wheat sensitivity" (NCWS). NCWS pathogenesis is still uncertain and attributed to very different mechanisms. We aimed to study the different T-lymphocyte subsets in the rectal mucosa of NCWS patients to demonstrate the possible contribution of adaptative immune response. Twelve patients (11 women, 1 man, age range 23-61 yr, median 32 yr) with a definitive diagnosis of NCWS were recruited at random for the present study. They underwent rectal endoscopy with multiple mucosal biopsies at the end of a double-blind placebo-controlled (DBPC) wheat challenge when they reported the reappearance of the symptoms. As controls we included 11 "healthy patients", sex- and age-matched with the patients who underwent colonoscopy evaluation for rectal bleeding due to hemorrhoids. Cells freshly obtained from rectal tissue were stained to detect anti-CD45, anti-CD3, anti-CD4, and anti-CD8. Furthermore, intracellular staining was performed with anti-tumor necrosis factor (TNF)-α, anti-interleukin (IL)-17, and anti-IL-22. Production of TNF-α by CD45+, CD3+, CD4+, and CD8+ cells, as well as of IL-17 by CD4+ cells, was higher in the rectal tissue of NCWS patients than in controls. On the contrary, IL-22 production by CD8+ cells was lower in NCWS patients than in the controls. In NCWS patients diagnosed by DBPC wheat challenge, there is a complex immunological activation, with a significant role for the adaptive response.NEW & NOTEWORTHY Nonceliac wheat sensitivity (NCWS) is a syndrome characterized by symptoms triggered by gluten intake. The pathogenesis is still uncertain. Studies have shown a role for innate immunity. We demonstrated that production of TNF-α by CD45+, CD3+, CD4+, and CD8+ cells and of IL-17 by CD4+ cells is higher in the rectal tissue of NCWS patients than in controls. We clearly demonstrated that in patients with NCWS there is a significant role for the adaptive response.

Mechanisms of Wheat Allergenicity in Mice: Comparison of Adjuvant-Free vs. Alum-Adjuvant Models.

Wheat protein is considered a major type of food allergen in many countries including the USA. The mechanisms of allergenicity of wheat proteins are not well understood at present. Both adjuvant-based and adjuvant-free mouse models are reported for this food allergy. However, it is unclear whether the mechanisms underlying wheat allergenicity in these two types of models are similar or different. Therefore, we compared the molecular mechanisms in a novel adjuvant-free (AF) model vs. a conventional alum-adjuvant (AA) model of wheat allergy using salt-soluble wheat protein (SSWP). In the AF model, Balb/cJ mice were sensitized with SSWP via skin exposure. In the AA model, mice were sensitized by an intraperitoneal injection of SSWP with alum. In both models, allergic reactions were elicited using an identical protocol. Robust IgE as well as mucosal mast cell protein-1 responses were elicited similarly in both models. However, an analysis of the spleen immune markers identified strikingly different molecular activation patterns in these two models. Furthermore, a number of immune markers associated with intrinsic allergenicity were also identified in both models. Since the AF model uses skin exposure without an adjuvant, the mechanisms in the AF model may more closely simulate the human wheat allergenicity mechanisms from skin exposure in occupational settings such as in the baking industry.

Gut microbiome alterations in patients with wheat-dependent exercise-induced anaphylaxis.

The intestinal microbiota plays a critical role in food allergy development. However, little is known regarding the structure and composition of the intestinal microbiota in patients with wheat-dependent exercise-induced anaphylaxis (WDEIA). We examined the gut microbiota alterations in patients with WDEIA and the microbiota's association with WDEIA. Fecal samples were collected from 25 patients with WDEIA and 25 healthy controls. Environmental exposure factors were obtained, serum total IgE, IgE specific to wheat, gluten, and ω-5 gliadin were measured. Fecal samples were profiled using 16S rRNA gene sequencing. The relative abundances of the bacterial genera Blautia (P < 0.05), Erysipelatoclostridium (P < 0.01), Akkermansia (P < 0.05) and Lachnospiraceae_NK4A136_group (P < 0.05) were significantly increased, while those of Lactobacillus (P = 0.001) and Dialister (P < 0.05) were significantly decreased in subjects with WDEIA. The microbial diversity did not differ between WDEIA patients and healthy controls. IgE specific to ω-5 gliadin was positively associated with the Oscillospira (r = 0.48, P < 0.05) and negatively associated with Leuconostoc (r = -0.49, P < 0.05). Total IgE levels were significantly negatively correlated with Bifidobacterium (P < 0.05). The gut microbiome compositions in WDEIA patients differed from those of healthy controls. We identified a potential association between the gut microbiome and WDEIA development. Our findings may suggest new methods for preventing and treating WDEIA.

Induction of Oral Tolerance by Pepsin-Digested Gliadin Retaining T Cell Reactivity in a Mouse Model of Wheat Allergy.

BACKGROUND: Wheat is known as the most widely consumed food all over the world. Although many types of wheat allergy have been recognized, their treatment still has a long way to go due to the complex pathogenesis. Oral immunotherapy (OIT) is under investigation for the treatment of wheat allergies. Previous studies have demonstrated that OIT using intact wheat allergens can induce tolerance, but is accompanied by a high risk of anaphylactic reactions. OBJECTIVES: Our objective was to prepare modified wheat allergens with hypoallergenic and tolerance-inducing properties to reduce adverse effects during immunotherapy. METHODS: Wheat gliadin was degraded by hydrolysis with pepsin and trypsin, and then the hydrolysate was deamidated with hydrochloric acid. The IgE-binding capacity and T cell reactivity of the degraded gliadins were evaluated in vitro. Pepsin-digested gliadin (peptic-GLI) was applied in a mouse model to investigate whether it would induce oral tolerance. RESULTS: Degradation with pepsin decreased IgE-binding capacity and maintained T cell reactivity. Oral administration of peptic-GLI to mice before sensitization and challenge with gliadin could significantly suppress the production of IgE, IgG1, and type 2 T helper cytokines. Moreover, the development of anaphylactic reactions and allergic responses of the small intestine induced by gliadin challenge were inhibited by oral administration of peptic-GLI. CONCLUSIONS: The findings of this study indicate that peptic-GLI with low allergenicity and potential for tolerance induction may become useful in wheat immunotherapy with less adverse effects.