Clinical utility of IgE antibodies to ω-5 gliadin in the diagnosis of wheat allergy: a pediatric multicenter challenge study.
ABSTRACT There are contradictory results regarding the clinical usefulness of the determination of IgE antibodies to ω-5 gliadin in children with a suspicion of wheat allergy (WA).
The study comprised 311 children and young adults with suspected wheat intolerance treated at three separate pediatric clinics and, with the exception of 25, were found to be positive in specific IgE antibody determinations to wheat. Their ages ranged from 6 months to 20.4 years (median age, 2.3 years). Possible relationships between IgE antibodies to ω-5 gliadin and a physician's diagnosis of WA and challenge symptoms were studied.
The mean concentration of IgE antibodies to ω-5 gliadin was 1.2 kU(A)/l in WA patients and <0.35 kU(A)/l in patients without WA (p < 0.0001). Seventy-two percent of the WA patients had positive ω-5 gliadin levels and 75% of the patients without WA had negative levels. Logistic regression showed a significant relationship between the probability of WA and the concentration of IgE antibodies to ω-5-gliadin with a 2.6-fold (95% CI: 2.0-3.3) increased risk. Age was an important factor to consider as the risk of WA increased 5.4-fold (95% CI: 1.4-21) for children ≤1 year of age and 2.5-fold (95% CI: 2.0-3.2) for children >1 year of age with increasing levels of IgE.
Detection of IgE to ω-5 gliadin seems to be associated with responsiveness to the challenge test and is particularly useful in infants with a suspicion of WA.
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ABSTRACT: Wheat allergy is among the most common food allergy in children, but few publications are available assessing the risk of anaphylaxis due to wheat. In this study, we report the case of near-fatal anaphylaxis to wheat in a patient undergoing an oral food challenge (OFC) after the ingestion of a low dose (256 mg) of wheat. Moreover, for the first time, we analyzed the risk of anaphylaxis during an OFC to wheat in 93 children, compared to other more commonly challenged foods such as milk, egg, peanuts, and soy in more than 1000 patients. This study, which includes a large number of OFCs to wheat, shows that wheat is an independent risk factor that is associated with anaphylaxis requiring epinephrine administration (Odds Ratio [OR] = 2.4) and anaphylaxis requiring epinephrine administration to low dose antigen (OR = 8.02). Other risk factors for anaphylaxis, anaphylaxis requiring epinephrine administration, and anaphylaxis to low dose antigen was a history of a prior reaction not involving only the skin (OR = 1.8, 1.9 and 1.8 respectively). None of the clinical variables available prior to performing the OFC could predict which children among those undergoing OFCs to wheat would develop anaphylaxis or anaphylaxis for low dose antigen. This study shows that wheat is an independent risk factor that is associated with anaphylaxis requiring epinephrine administration and anaphylaxis requiring epinephrine administration to low dose antigen.World Allergy Organization Journal 08/2013; 6(1):14.
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ABSTRACT: Food-dependent exercise-induced anaphylaxis (FDEIA) is a special form of IgE-mediated food allergy and exhibits allergic symptoms in combination of causative food-intake and triggers such as exercise. As the causative foods and the condition of triggers vary among patients, diagnosis of FDEIA is not always easy. Serum food-specific IgE tests, which are widely used in the diagnosis of FDEIA, have rather low sensitivity, because the tests mostly utilize crude extracts of foods. Concept of using defined allergen molecules has been proposed as the term "component-resolved diagnostics" for diagnosis of IgE-mediated allergy. Use of purified allergens such as recombinant omega-5 gliadin turned out to highly improve its sensitivity and specificity of the tests in the diagnosis of wheat-dependent exercise-induced anaphylaxis (WDEIA). Recently, CD203c expression-based basophil activation test (BAT) is reported to be useful in identifying adult patients with WDEIA and predicting causative allergens in WDEIA, when combined with appropriate allergens. Detection of serum allergen levels possibly gives useful information whether food challenge tests have been performed with sufficient strength.Journal of dermatological science 04/2013; · 3.71 Impact Factor
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ABSTRACT: Molecular-based allergy (MA) diagnostics is an approach used to map the allergen sensitization of a patient at a molecular level, using purified natural or recombinant allergenic molecules (allergen components) instead of allergen extracts. Since its introduction, MA diagnostics has increasingly entered routine care, with currently more than 130 allergenic molecules commercially available for in vitro specific IgE (sIgE) testing.MA diagnostics allows for an increased accuracy in allergy diagnosis and prognosis and plays an important role in three key aspects of allergy diagnosis: (1) resolving genuine versus cross-reactive sensitization in poly-sensitized patients, thereby improving the understanding of triggering allergens; (2) assessing, in selected cases, the risk of severe, systemic versus mild, local reactions in food allergy, thereby reducing unnecessary anxiety for the patient and the need for food challenge testing; and (3) identifying patients and triggering allergens for specific immunotherapy (SIT).Singleplex and multiplex measurement platforms are available for MA diagnostics. The Immuno-Solid phase Allergen Chip (ISAC) is the most comprehensive platform currently available, which involves a biochip technology to measure sIgE antibodies against more than one hundred allergenic molecules in a single assay. As the field of MA diagnostics advances, future work needs to focus on large-scale, population-based studies involving practical applications, elucidation and expansion of additional allergenic molecules, and support for appropriate test interpretation. With the rapidly expanding evidence-base for MA diagnosis, there is a need for allergists to keep abreast of the latest information. The aim of this consensus document is to provide a practical guide for the indications, determination, and interpretation of MA diagnostics for clinicians trained in allergology.World Allergy Organization Journal 10/2013; 6(1):17.