Efficacy and safety of omalizumab in adult patients with wheat-dependent exercise-induced anaphylaxis: Reduction of in vitro basophil activation and allergic reaction to wheat.

BACKGROUND: In patients with wheat-dependent exercise-induced anaphylaxis (WDEIA), anaphylactic shock occurs frequently, therefore avoidance of wheat products is recommended. We aimed to evaluate efficacy and safety of long-term omalizumab treatment for adult patients with WDEIA. METHODS: In this phase 2, multicentre single-arm trial, 20 adult patients with WDEIA were enrolled (UMIN 000019250). All patients were administered 150-600 mg of omalizumab subcutaneously and evaluations (basophil activation and blood examination) were performed at regular intervals during administration period (0-48 weeks) and observation period (48-68 weeks). Primary endpoint was proportion of the patients who achieved a basophil activation rate below 10% with fractionated wheat preparations, and secondary endpoint was proportion of the patients with no allergic reactions after wheat products ingestion. RESULTS: During the omalizumab treatment, more than 80% of the patients achieved the basophil activation rate less than 10% against all fractionated wheat preparations, and 68.8% of the patients who achieved the primary endpoint experienced no allergic reaction. During the observation period, the proportion of the patients who achieved a basophil activation rate below 10% decreased gradually, and the proportion of patients with positive allergic reactions increased gradually thereafter and reached maximum of 46.7%. Severe adverse events were not observed during the study. CONCLUSIONS: Long-term omalizumab treatment is safe and effective for adult patients with WDEIA when assessed by basophil activation rate with wheat allergens as well as allergic reactions after lifting of restrictions on wheat intake. However, this is not enough to achieve desensitization.

Intestinal Barrier Function in Gluten-Related Disorders.

Gluten-related disorders include distinct disease entities, namely celiac disease, wheat-associated allergy and non-celiac gluten/wheat sensitivity. Despite having in common the contact of the gastrointestinal mucosa with components of wheat and other cereals as a causative factor, these clinical entities have distinct pathophysiological pathways. In celiac disease, a T-cell mediate immune reaction triggered by gluten ingestion is central in the pathogenesis of the enteropathy, while wheat allergy develops as a rapid immunoglobulin E- or non-immunoglobulin E-mediated immune response. In non-celiac wheat sensitivity, classical adaptive immune responses are not involved. Instead, recent research has revealed that an innate immune response to a yet-to-be-defined antigen, as well as the gut microbiota, are pivotal in the development in this disorder. Although impairment of the epithelial barrier has been described in all three clinical conditions, its role as a potential pathogenetic co-factor, specifically in celiac disease and non-celiac wheat sensitivity, is still a matter of investigation. This article gives a short overview of the mucosal barrier of the small intestine, summarizes the aspects of barrier dysfunction observed in all three gluten-related disorders and reviews literature data in favor of a primary involvement of the epithelial barrier in the development of celiac disease and non-celiac wheat sensitivity.

Gluten Vehicle and Placebo for Non-Celiac Gluten Sensitivity Assessment.

Non-celiac gluten sensitivity (NCGS) is a syndrome characterized by gastrointestinal and extraintestinal manifestations triggered after gluten ingestion in the absence of celiac disease and wheat allergy. Because of the lack of biomarkers for NCGS diagnosis, the cornerstone for its assessment is a single- or double-blind placebo-controlled (DBPC) gluten challenge. However, there are some non-standardized points in the diagnostic approach proposed by the experts. This complicate comparisons among the results published by different research groups. The gluten vehicle and placebo must be indistinguishable from each other, which entails sensory and technological evaluations of the designed gluten vehicle and placebo products. At the moment, there is no standardized method for the preparation of the gluten vehicle and placebo for carrying out DBPC gluten challenges for NCGS assessment. This review focuses on the challenges that researchers have to face, either for the development of an accepted gluten vehicle and placebo or for identifying NCGS cases on the basis of DBPC gluten challenges.

Non-celiac gluten/wheat sensitivity: still more questions than answers.

Non-celiac gluten/wheat sensitivity (NCG/WS) is a syndrome characterized by intestinal and extra-intestinal sym-ptoms elicited by gluten/wheat ingestion in the persons, who are not affected by celiac disease and wheat allergy. Due to the lack of established biomarkers, the diagnosis of NCG/WS is based on the clinical picture, and it is necessary to validate it in well-defined double-blind, placebo-controlled challenge (The Salerno Experts´ Criteria). In the article is discussed a current knowledge of NCG/WS in terms of pathogenesis, diagnosis and treatment. Key words: gluten - gluten-related disorders - non-celiac gluten/wheat sensitivity - wheat.

Modulative effect of a new hydrazide derivative on wheat-induced pulmonary inflammation in rats.

NEW FINDINGS: What is the central question of this study? What is the mechanism of wheat-induced pulmonary inflammation and how does a hydrazide derivative modulate it? What is the main finding and its importance? A hydrazide derivative significantly reduced wheat-induced pulmonary inflammation in a rat model mainly by down-regulating inflammatory cell infiltration, pathological lesions in the lungs and the level of pro-inflammatory cytokines, COX-1, COX-2 and T-cell proliferation. ABSTRACT: We investigated the ameliorative anti-inflammatory effect of a previously synthesized hydrazide derivative (N'-(4-methoxybenzylidene)-6-(4-chlorophenyl)-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carbohydrazide; MD) as an immunomodulator in a newly developed allergen-induced pulmonary inflammation (AIPI) rat model. Wheat and thresher dust were used as allergens to induce pulmonary inflammation while MD was used to reverse the inflammatory response. Blood and bronchoalveolar lavage fluid (BALF) were collected after killing the rats and inflammatory cells were counted. Histological analysis of lung airways was carried out by haematoxylin and eosin and periodic acid-Schiff staining while the level of total serum IgE, interleukin (IL)-4, IL-5 and cyclooxygenase (COX)-1 in BALF and in vitro T-cell proliferation in spleen were measured through enzyme-linked immunosorbent assay. mRNA expression level of IL-4, IL-5, IL-13, transforming growth factor ß (TGF-ß), interferon-γ, tumour necrosis factor α, COX-1 and COX-2 was evaluated by qRT-PCR. A liver and kidney function test was used to observe any toxic impact of MD. The results indicated that 2 mg of wheat and thresher dust led to higher levels of inflammatory cytokines in the blood, BALF and lung airways of rats. MD potentially down-regulated the inflammatory cell infiltration in BALF and pathological lesions in the lung airways of AIPI rats. MD significantly suppressed the elevated total serum IgE, along with IL-4, IL-5, IL-13, TGF-ß, COX-1 and COX-2 mRNA expression and T-cell proliferation in spleen. In conclusion, MD at 10 mg kg-1 exhibited a significant reduction in all the markers in both wheat- and thresher dust-induced pulmonary inflammation mainly by inhibiting pro-inflammatory cytokine production and T-cell proliferation. The data suggest that inhibition of the T-cell response may be responsible for the modulative effect of MD in an AIPI rat model.

Favorable prognosis of wheat allergy in adults

Background: Wheat ingestion can lead to disorders such as IgE-mediated food allergy and wheat-dependent exercise-induced anaphylaxis (WDEIA), both of which are associated with impaired quality of life and significant morbidity. Allergy to wheat is relatively benign in children, although its natural history in adults is still unknown. Objective: We used placebo-controlled challenge to evaluate the natural history of wheat hypersensitivity in atopic patients with adult-onset wheat allergy. Methods: We enrolled 13 patients from an initial cohort of adult patients with IgE-mediated wheat allergy (mean age, 40 years). After diagnosis, the patients observed a wheat-free diet and were followed as outpatients for 5 years to evaluate wheat exposure. Wheat-IgE titers were determined at the end of follow-up, and a second wheat-challenge was performed. Results: Ten out of 13 patients took part in the study. The mean period of wheat avoidance was 4.2 years. Three patients had spontaneously reintroduced wheat before the second evaluation, after a mean (IQR) of 28 (18-36) months, with only mild gastrointestinal discomfort at reintroduction. At the end of follow-up, 9 of the 10 patients were wheat-tolerant. Two patients had a history of WDEIA. We observed a reduction in IgE levels, with median (IQR) IgE falling from 2.77 (0.35-100) kU/L at diagnosis to 0.88 (0.1-20.8) kU/L. The association between IgE and a negative challenge result was not statistically significant.Conclusion: IgE-mediated wheat allergy in adults is benign and represents a temporary break in gastrointestinal tolerance. Future studies may improve our knowledge of wheat allergens, routes of and factors leading to sensitization, and prognostic biomarkers

Introducción: La ingesta de trigo puede originar varias patologías como alergia alimentaria mediada por IgE y la anafilaxia inducida por ejercicio previa ingesta de trigo. Todas ellas originan un descenso en la calidad de vida y una importante morbilidad. La alergia a trigo es relativamente benigna en niños, sin embargo, su historia natural en adultos es aún desconocida. Objetivo: Evaluamos la historia natural de la hipersensibilidad al trigo de inicio en la edad adulta en pacientes atópicos confirmado mediante pruebas de exposición oral. Métodos: Se incluyeron 13 pacientes de una cohorte de pacientes adultos (edad media 40 años) con alergia a trigo mediada por IgE. Tras el diagnóstico los pacientes siguieron una dieta exenta de trigo y fueron seguidos durante 5 años para valorar su tolerancia tras la exposición al trigo. Al final del seguimiento se determinaron los valores de IgE específica a trigo y se realizó una segunda provocación oral con trigo. Resultados: 10 de los 13 pacientes tomaron parte en el estudio. La duración media del periodo de no ingesta de trigo fue de 4,2 años. 3 pacientes reintrodujeron por iniciativa propia la ingesta de trigo antes de la segunda evaluación, después de un periodo medio de 28 meses (RIQ 18-36 meses), presentando solo leves síntomas gastrointestinales. Al final del seguimiento, 9/10 pacientes toleraron la ingesta de trigo. 2 pacientes tenían historia de anafilaxia inducida por ejercicio. Se observó una disminución de los valores de IgE específica desde una mediana de 2,77 kU/l (RIQ 0,35-100 kU/L) en el momento del diagnóstico hasta 0,88 kU/l (RIQ 0,1-20,8 Ku/L) al final del seguimiento. No se observó correlación entre los valores de IgE específica y los resultados de la tolerancia final. Conclusión: La alergia a trigo mediada por IgE en adultos es una patología benigna y representa una interrupción temporal de la tolerancia gastrointestinal. Futuros estudios podrían mejorar nuestro conocimiento sobre los alérgenos del trigo, rutas y factores que llevan a la sensibilización, y biomarcadores de pronóstico

Using a gluten oral food challenge protocol to improve diagnosis of wheat-dependent exercise-induced anaphylaxis.

BACKGROUND: Oral wheat plus cofactors challenge tests in patients with wheat-dependent exercise-induced anaphylaxis (WDEIA) produce unreliable results. OBJECTIVE: We sought to confirm WDEIA diagnosis by using oral gluten flour plus cofactors challenge, to determine the amount of gluten required to elicit symptoms, and to correlate these results with plasma gliadin levels, gastrointestinal permeability, and allergologic parameters. METHODS: Sixteen of 34 patients with a history of WDEIA and ω5-gliadin IgE underwent prospective oral challenge tests with gluten with or without cofactors until objective symptoms developed. Gluten reaction threshold levels, plasma gliadin concentrations, gastrointestinal permeability, sensitivities and specificities for skin prick tests, and specific IgE levels were ascertained in patients and 38 control subjects. RESULTS: In 16 of 16 patients (8 female and 8 male patients; age, 23-76 years), WDEIA was confirmed by challenges with gluten alone (n = 4) or gluten plus cofactors (n = 12), including 4 patients with previous negative wheat challenge results. Higher gluten doses or acetylsalicylic acid (ASA) plus alcohol instead of physical exercise were cofactors in 2 retested patients. The cofactors ASA plus alcohol and exercise increased plasma gliadin levels (P < .03). Positive challenge results developed after a variable period of time at peak or when the plateau plasma gliadin level was attained. Positive plasma gliadin threshold levels differed by greater than 100-fold and ranged from 15 to 2111 pg/mL (median, 628 pg/mL). The clinical history, IgE gliadin level, and baseline gastrointestinal level were not predictive of the outcomes of the challenge tests. The challenge-confirmed sensitivity and specificity of gluten skin prick tests was 100% and 96%, respectively. CONCLUSION: Oral challenge with gluten alone or along with ASA and alcohol is a sensitive and specific test for the diagnosis of WDEIA. Exercise is not an essential trigger for the onset of symptoms in patients with WDEIA.