WAO consensus on DEfinition of Food Allergy SEverity (DEFASE).

Background: While several scoring systems for the severity of anaphylactic reactions have been developed, there is a lack of consensus on definition and categorisation of severity of food allergy disease as a whole. Aim: To develop an international consensus on the severity of food allergy (DEfinition of Food Allergy Severity, DEFASE) scoring system, to be used globally. Methods Phase 1: We conducted a mixed-method systematic review (SR) of 11 databases for published and unpublished literature on severity of food allergy management and set up a panel of international experts. Phase 2: Based on our findings in Phase 1, we drafted statements for a two-round modified electronic Delphi (e-Delphi) survey. A purposefully selected multidisciplinary international expert panel on food allergy (n = 60) was identified and sent a structured questionnaire, including a set of statements on different domains of food allergy severity related to symptoms, health-related quality of life, and economic impact. Participants were asked to score their agreement on each statement on a 5-point Likert scale ranging from "strongly agree" to "strongly disagree". Median scores and percentage agreements were calculated. Consensus was defined a priori as being achieved if 70% or more of panel members rated a statement as "strongly agree" to "agree" after the second round. Based on feedback, 2 additional online voting rounds were conducted. Results: We received responses from 92% of Delphi panel members in round 1 and 85% in round 2. Consensus was achieved on the overall score and in all of the 5 specific key domains as essential components of the DEFASE score. Conclusions: The DEFASE score is the first comprehensive grading of food allergy severity that considers not only the severity of a single reaction, but the whole disease spectrum. An international consensus has been achieved regarding a scoring system for food allergy disease. It offers an evaluation grid, which may help to rate the severity of food allergy. Phase 3 will involve validating the scoring system in research settings, and implementing it in clinical practice.

Prevalence and early-life risk factors of school-age allergic multimorbidity: The EuroPrevall-iFAAM birth cohort.

BACKGROUND: Coexistence of childhood asthma, eczema and allergic rhinitis is higher than can be expected by chance, suggesting a common mechanism. Data on allergic multimorbidity from a pan-European, population-based birth cohort study have been lacking. This study compares the prevalence and early-life risk factors of these diseases in European primary school children. METHODS: In the prospective multicentre observational EuroPrevall-iFAAM birth cohort study, we used standardized questionnaires on sociodemographics, medical history, parental allergies and lifestyle, and environmental exposures at birth, 12 and 24 months. At primary school age, parents answered ISAAC-based questions on current asthma, rhinitis and eczema. Allergic multimorbidity was defined as the coexistence of at least two of these. RESULTS: From 10,563 children recruited at birth in 8 study centres, we included data from 5,572 children (mean age 8.2 years; 51.8% boys). Prevalence estimates were as follows: asthma, 8.1%; allergic rhinitis, 13.3%; and eczema, 12.0%. Allergic multimorbidity was seen in 7.0% of the whole cohort, ranging from 1.2% (Athens, Greece) to 10.9% (Madrid, Spain). Risk factors for allergic multimorbidity, identified with AICc, included family-allergy-score, odds ratio (OR) 1.50 (95% CI 1.32-1.70) per standard deviation; early-life allergy symptoms, OR 2.72 (2.34-3.16) for each symptom; and caesarean birth, OR 1.35 (1.04-1.76). Female gender, OR 0.72 (0.58-0.90); older siblings, OR 0.79 (0.63-0.99); and day care, OR 0.81 (0.63-1.06) were protective factors. CONCLUSION: Allergic multimorbidity should be regarded as an important chronic childhood disease in Europe. Some of the associated early-life factors are modifiable and may be considered for prevention strategies.

Efficacy and safety of sublingual immunotherapy with grass allergen tablets for seasonal allergic rhinoconjunctivitis.

BACKGROUND: Allergen immunotherapy (desensitization) by injection is effective for seasonal allergic rhinitis and has been shown to induce long-term disease remission. The sublingual route also has potential, although definitive evidence from large randomized controlled trials has been lacking. OBJECTIVE: The aim was to confirm the efficacy of a rapidly dissolving grass allergen tablet (GRAZAX, ALK-Abelló, Hørsholm, Denmark) compared with placebo in patients with seasonal rhinoconjunctivitis. METHODS: A longitudinal, double-blind, placebo-controlled, parallel-group study that included 51 centers from 8 countries. Subjects were randomized (1:1) to receive a grass allergen tablet or placebo once daily. A total of 634 subjects with a history of grass pollen-induced rhinoconjunctivitis for at least 2 years and confirmation of IgE sensitivity (positive skin prick test and serum-specific IgE) were included in the study. Subjects commenced treatment at least 16 weeks before the grass pollen season, and treatment was continued throughout the entire season. RESULTS: The primary efficacy analysis showed a reduction of 30% in rhinoconjunctivitis symptom score (P < .0001) and a reduction of 38% in rhinoconjunctivitis medication score (P < .0001) compared with placebo. Side effects mainly comprised mild itching and swelling in the mouth that was in general well tolerated and led to treatment withdrawal in less than 4% of participants. There were no serious local side effects and no severe systemic adverse events. CONCLUSION: Sublingual immunotherapy with grass allergen tablets was effective in grass pollen-induced rhinoconjunctivitis. The tablet was well tolerated with minor local side effects. CLINICAL IMPLICATIONS: The grass allergen tablet represents a safe alternative to injection immunotherapy suitable for home use.

IgE binding to pepsin-digested food extracts.

BACKGROUND: Pepsin resistance of allergens like lipid transfer protein and 2S albumin has been suggested as explanation for the severity of symptoms often induced by these allergens. Component-resolved diagnosis with purified labile and stable allergens has therefore been proposed to better characterize the risk involved in a positive in vitro IgE test. However, for many foods, purified allergens are not (yet) available. OBJECTIVE: It was the aim of this study to evaluate the potential of pepsin-digested whole-food extracts to distinguish between IgE responses to stable (potentially severe) and labile (mild) allergens. METHODS: Sera (n = 143) from Italian, Spanish and Dutch patients with hazelnut and/or apple ingestion-related symptoms were analyzed for residual IgE binding to pepsin-resistant hazelnut and/or apple allergens. Control and pepsin-digested hazelnut and apple extracts were used for radioallergosorbent test analysis and immunoblot analysis. RESULTS: Pepsin digestion of food extracts, like from hazelnut and apple used for in vitro diagnostic tests, provides a way to distinguish sensitization to pepsin-resistant allergens from that to pepsin-susceptible allergens. In this selected group of patients, IgE reactivity to pepsin-digested extracts correlated with sensitization to the stable allergen lipid transfer protein. The analysis further revealed that the use of soluble pepsin can result in false-positive in vitro tests (2/143). CONCLUSION: Pepsin-digested food extracts are a convenient tool to identify patients with IgE antibodies against potentially dangerous stable allergens, in particular for those foods where the relevant stable allergens have not yet been identified. This can increase the clinical prognostic value of food allergy serology.

Lipid transfer proteins from fruit: cloning, expression and quantification.

BACKGROUND: Lipid transfer proteins (LTP) are stable, potentially life-threatening allergens in fruits and many other vegetable foods. The aim of this study was to clone and express recombinant apple LTP (Mal d 3), as has previously been done for peach LTP (Pru p 3) and set up quantitative tests for measuring fruit LTPs. METHODS: cDNA for Mal d 3 and Pru p 3 was cloned, expressed in the yeast Pichia pastoris and the resulting proteins were purified via cation exchange chromatography. The immune reactivity of rMal d 3 was compared to nMal d 3 by RAST (inhibition), immunoblotting and basophil histamine release testing. To obtain monoclonal and monospecific polyclonal antibodies, mice and rabbits were immunized with purified nMal d 3. RESULTS: The deduced amino acid sequence of Mal d 3 was identical to the published sequence, Pru p 3 differed at two positions (S9A and S76H). The rMal d 3 had an IgE-binding potency and biological activity close to its natural counterpart. One sandwich ELISA selectively detecting apple LTP and another cross-reactive with cherry, nectarine and hazelnut LTP were developed. In addition, a competitive RIA was developed with polyclonal rabbit antiserum and labeled nMal d 3. CONCLUSION: rMal d 3 (as shown before for rPru p 3) may be a useful tool for application in component-resolved diagnosis of food allergy. Assays for the measurement of LTP will increase the traceability of this potentially dangerous allergen.