Background Component-resolved diagnosis has been shown to improve the diagnosis of food allergy. Objective We sought to evaluate whether component-resolved diagnosis might help to identify patients ...at risk of objective allergic reactions to hazelnut. Method A total of 161 hazelnut-sensitized patients were included: 40 children and 15 adults with objective symptoms on double-blind, placebo-controlled food challenges (DBPCFCs) and 24 adults with a convincing objective history were compared with 41 children and 41 adults with no or subjective symptoms on DBPCFCs (grouped together). IgE levels to hazelnut extract and single components were analyzed with ImmunoCAP. Results IgE levels to hazelnut extract were significantly higher in children with objective than with no or subjective symptoms. In 13% of children and 49% of adults with hazelnut allergy with objective symptoms, only sensitization to rCor a 1.04 was observed and not to other water-soluble allergens. Sensitization to rCor a 8 was rare, which is in contrast to rCor a 1. Sensitization to nCor a 9, rCor a 14, or both was strongly associated with hazelnut allergy with objective symptoms. By using adapted cutoff levels, a diagnostic discrimination between severity groups was obtained. IgE levels to either nCor a 9 of 1 kUA /L or greater or rCor a 14 of 5 kUA /L or greater (children) and IgE levels to either nCor a 9 of 1 kUA /L or greater or rCor a 14 of 1 kUA /L or greater (adults) had a specificity of greater than 90% and accounted for 83% of children and 44% of adults with hazelnut allergy with objective symptoms. Conclusion Sensitization to Cor a 9 and Cor a 14 is highly specific for patients with objective symptoms in DBPCFCs as a marker for a more severe hazelnut allergic phenotype.
Solving the structure of Pla l 1 elucidated the preserved fold of Ole e 1-like proteins while IgE cross-reactivity in this family is limited to molecules with high sequence identity. Diagnostic ...accuracy using source-specific Ole e 1-like molecules is essential for discriminating plantain from other pollen allergies.
Background Kiwifruit is a common cause of food allergy. Symptoms range from mild to anaphylactic reactions. Objective We sought to elucidate geographic differences across Europe regarding clinical ...patterns and sensitization to kiwifruit allergens. Factors associated with the severity of kiwifruit allergy were identified, and the diagnostic performance of specific kiwifruit allergens was investigated. Methods This study was part of EuroPrevall, a multicenter European study investigating several aspects of food allergy. Three hundred eleven patients with kiwifruit allergy from 12 countries representing 4 climatic regions were included. Specific IgE to 6 allergens (Act d 1, Act d 2, Act d 5, Act d 8, Act d 9, and Act d 10) and kiwifruit extract were tested by using ImmunoCAP. Results Patients from Iceland were mainly sensitized to Act d 1 (32%), those from western/central and eastern Europe were mainly sensitized to Act d 8 (pathogenesis-related class 10 protein, 58% and 44%, respectively), and those from southern Europe were mainly sensitized to Act d 9 (profilin, 31%) and Act d 10 (nonspecific lipid transfer protein, 22%). Sensitization to Act d 1 and living in Iceland were independently and significantly associated with severe kiwifruit allergy (odds ratio, 3.98 P = .003 and 5.60 P < .001, respectively). Using a panel of 6 kiwifruit allergens in ImmunoCAP increased the diagnostic sensitivity to 65% compared with 20% for skin prick tests and 46% ImmunoCAP using kiwi extract. Conclusion Kiwifruit allergen sensitization patterns differ across Europe. The use of specific kiwifruit allergens improved the diagnostic performance compared with kiwifruit extract. Sensitization to Act d 1 and living in Iceland are strong risk factors for severe kiwifruit allergy.
Thirty percent of children with food allergies have multiple simultaneous allergies; however, the features of these multiple allergies are not well characterized serologically or clinically.
We ...comprehensively evaluated 60 multifood-allergic patients by measuring serum IgE to key allergen components, evaluating clinical histories and medication use, performing skin tests, and conducting double-blind, placebo-controlled food challenges (DBPCFCs).
Sixty participants with multiple food allergies were characterized by clinical history, DBPCFCs, total IgE, specific IgE, and component-resolved diagnostics (IgE and IgG4) data. The food allergens tested were almond, egg, milk, sesame, peanut, pecan, walnut, hazelnut, cashew, pistachio, soy, and wheat.
Our data demonstrate that of the reactions observed during a graded DBPCFC, gastrointestinal reactions occurred more often in boys than in girls, as well as in individuals with high levels of IgE to 2S albumins from cashew, walnut, and hazelnut. Certain food allergies often occurred concomitantly in individuals (ie, cashew/pistachio and walnut/pecan/hazelnut). IgE testing to components further corroborated serological relationships between and among these clustered food allergies.
Associations of certain food allergies were shown by DBPCFC outcomes as well as by correlations in IgE reactivity to structurally related food allergen components. Each of these criteria independently demonstrated a significant association between allergies to cashew and pistachio, as well as among allergies to walnut, pecan, and hazelnut.
Background Analysis of IgE antibody binding to epitopes provides information for food allergy diagnosis and management and construction of hypoallergenic candidate vaccines, but the contribution of ...sequential epitopes to functionally relevant IgE binding is not fully understood. Objectives We sought to study the impact of IgE-binding peptides described as major sequence epitopes in the literature on IgE-binding capacity of 2 selected food allergens. Methods IgE-binding peptides of the food allergens Ara h 2 (peanut) and Pen a 1 (shrimp) were identified. Synthetic soluble peptides representing the identified sequences were assessed for their capacity to inhibit IgE binding to the parent allergens by means of ELISA and in mediator release assay. The IgE-binding capacity of unfolded recombinant (r) Ara h 2 was analyzed. A hybrid tropomyosin carrying the IgE-binding regions of Pen a 1 grafted into the structural context of the nonallergenic mouse tropomyosin was applied in ELISA inhibition experiments and ImmunoCAP analysis. Results Although IgE-binding peptides representing sections of the allergen sequences were detected, no relevant capacity to inhibit the IgE binding to the parent allergen in ELISA or basophil activation test was observed. Unfolded rAra h 2 showed reduced IgE-binding capacity compared with folded rAra h 2 and failed to elicit mediator release. Hybrid tropomyosin bound less IgE than rPen a 1 in ImmunoCAP analysis and revealed marginal inhibitory capacity. Conclusion Peptides identified as major sequence epitopes on Pen a 1 and Ara h 2 show little contribution to the IgE binding of the allergens studied.
Commercial apple extracts (AEs) do not show satisfactory sensitivity in diagnostic procedures, and SPTs with fresh apple (prick-to-prick) proved to be more sensitive in confirming a history of ...apple-induced OAS.3 However, the content of Mal d 1 varies in different apple strains4 and is additionally affected by postharvest storage conditions.5 Hence prick-to-prick testing with fresh apple cannot be regarded as a standardized diagnostic procedure. Because rMal d 1 can be produced in defined and consistent qualities and quantities, it might improve the sensitivity of diagnostic tests for apple allergy. Considering a mean wheal diameter of 3 mm or larger as positive, all patients showed skin reactivity to rBet v 1, and 20 of 21 patients had positive reactions to BPE (Table I). ...in accordance with previous data, rBet v 1 was more sensitive than BPE in SPTs (100% and 95.2%, respectively) to diagnose birch pollen allergy.7 Wheal sizes induced by rBet v 1 were significantly larger than those induced by BPE (P = .001, Wilcoxon signed-rank test). rMal d 1 induced dose-dependent skin reactions in patients with apple allergy (Fig 1, A).
Background Antibodies and T cells specific for the major birch pollen allergen Bet v 1 cross-react with structurally related food allergens, such as Mal d 1 in apple. Objective We sought to evaluate ...the effects of oral uptake of Mal d 1 on the allergen-specific immune response in patients with birch pollen allergy. Methods Patients received 50 μg of rBet v 1 sublingually on 2 consecutive days outside of the birch pollen season. One year later, equal amounts of rMal d 1 were administered. Blood samples were collected before and after oral exposure, as well as before and after the intermediate birch pollen season. Allergen-specific IgE levels were determined by using ImmunoCAP. Proliferation of allergen-stimulated PBMCs was assessed, as well as the expression of IL-5, IL-13, IL-10, IFN-γ, and forkhead box protein 3 (Foxp3) in isolated T cells (real-time PCR). Allergen-specific T-cell lines were analyzed for epitope recognition. Results Orally administered Bet v 1 transiently reduced Bet v 1–specific serum IgE levels, as well as Bet v 1– and Mal d 1–induced T-cell proliferation, and enhanced the expression of IL-5, IL-10, and Foxp3. Orally applied Mal d 1 significantly decreased Bet v 1– and Mal d 1–specific IgE levels and induced IL-5 and IL-10 but no Foxp3 expression. In contrast to Bet v 1, Mal d 1 triggered IFN-γ production and T cells with a different epitope repertoire. Inhalation of birch pollen significantly enhanced allergen-specific IgE levels, T-cell proliferation, and IL-5, IL-10, IL-13, and Foxp3 expression. Conclusion Two sublingual administrations of 50 μg of Mal d 1 were well tolerated and induced transient immune responses seen during peripheral tolerance development. Thus recombinant Mal d 1 might be suitable and relevant for sublingual treatment of birch pollen–related apple allergy.
...our data suggest that IgE binding to nApi m 1 and rApi m 1 (i208) is comparable in CCD-negative patients with BV allergy and that only a minority of patients displaying low levels of IgE to ...nApi m 1 might not be detected by rApi m 1.
Rationale Serological peanut component testing is currently the most clinically predictive application of allergenic components in the diagnosis of human allergic disease.
Results Clinical (Jaccard index based on positive DBPCFC) and serological (Spearman's rhos of IgE levels) results demonstrated significant (q-value < 0.05) association (co-occurrence/positive ...correlation) between cashew and pistachio allergies as well as between walnut, pecan and hazelnut allergies.
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