Molecular Diagnosis in House Dust Mite-Allergic Patients Suggests That Der p 23 Is Clinically Relevant in Asthmatic Children.

BACKGROUND: Patterns of sensitization to house dust mites depend on geographic area and are important in clinical practice. However, the role of molecular diagnosis is not currently defined. We sought to characterize a pediatric population by focusing on sensitization to different mite species and major mite components in order to assess the clinical relevance of sensitization to allergenic components in our practice. METHODS: Consecutive children with respiratory allergy sensitized to house dust mites (determined by skin prick test [SPT]) were recruited. We determined specific IgE to nDer p 1, rDer p 2, and rDer p 23 using ImmunoCAP and sIgE using ImmunoCAP-ISAC microarray. Patients were followed up for 3 years. RESULTS: A total of 276 children were recruited. The frequency of sensitization was 86.6% for nDer p 1, 79.3% for rDer p 2, and 75.8% for rDer p 23. Lepidoglyphus species was the most common storage mite detected by SPT. Twenty-six patients (9.4%) were not sensitized to Der p 1 or Der p 2. It is noteworthy that IgE binding to Der p 23 was positive in 14 (53.8%). Asthmatic patients, especially those with a persistent moderate-severe phenotype, more frequently recognized the 3 major allergens. CONCLUSIONS: Most patients with mite allergy were sensitized to the major allergens Der p 1, Der p 2, and Der p 23. Of the allergens evaluated, 5% were sensitized to Der p 23 but not to Der p 1 or Der p 2. Sensitization to Der p 23 should be considered in the diagnosis and treatment of mite allergy, especially in patients with moderate-severe asthma, because it may worsen the clinical phenotype.

EAACI Guidelines on allergen immunotherapy: IgE-mediated food allergy.

Food allergy can result in considerable morbidity, impairment of quality of life, and healthcare expenditure. There is therefore interest in novel strategies for its treatment, particularly food allergen immunotherapy (FA-AIT) through the oral (OIT), sublingual (SLIT), or epicutaneous (EPIT) routes. This Guideline, prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Task Force on Allergen Immunotherapy for IgE-mediated Food Allergy, aims to provide evidence-based recommendations for active treatment of IgE-mediated food allergy with FA-AIT. Immunotherapy relies on the delivery of gradually increasing doses of specific allergen to increase the threshold of reaction while on therapy (also known as desensitization) and ultimately to achieve post-discontinuation effectiveness (also known as tolerance or sustained unresponsiveness). Oral FA-AIT has most frequently been assessed: here, the allergen is either immediately swallowed (OIT) or held under the tongue for a period of time (SLIT). Overall, trials have found substantial benefit for patients undergoing either OIT or SLIT with respect to efficacy during treatment, particularly for cow's milk, hen's egg, and peanut allergies. A benefit post-discontinuation is also suggested, but not confirmed. Adverse events during FA-AIT have been frequently reported, but few subjects discontinue FA-AIT as a result of these. Taking into account the current evidence, FA-AIT should only be performed in research centers or in clinical centers with an extensive experience in FA-AIT. Patients and their families should be provided with information about the use of FA-AIT for IgE-mediated food allergy to allow them to make an informed decision about the therapy.

Allergen immunotherapy for IgE-mediated food allergy: a systematic review and meta-analysis.

BACKGROUND: The European Academy of Allergy and Clinical Immunology (EAACI) is developing Guidelines for Allergen Immunotherapy (AIT) for IgE-mediated Food Allergy. To inform the development of clinical recommendations, we sought to critically assess evidence on the effectiveness, safety and cost-effectiveness of AIT in the management of food allergy. METHODS: We undertook a systematic review and meta-analysis that involved searching nine international electronic databases for randomized controlled trials (RCTs) and nonrandomized studies (NRS). Eligible studies were independently assessed by two reviewers against predefined eligibility criteria. The quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs and the Cochrane ACROBAT-NRS tool for quasi-RCTs. Random-effects meta-analyses were undertaken, with planned subgroup and sensitivity analyses. RESULTS: We identified 1814 potentially relevant papers from which we selected 31 eligible studies, comprising of 25 RCTs and six NRS, studying a total of 1259 patients. Twenty-five trials evaluated oral immunotherapy (OIT), five studies investigated sublingual immunotherapy, and one study evaluated epicutaneous immunotherapy. The majority of these studies were in children. Twenty-seven studies assessed desensitization, and eight studies investigated sustained unresponsiveness postdiscontinuation of AIT. Meta-analyses demonstrated a substantial benefit in terms of desensitization (risk ratio (RR) = 0.16, 95% CI 0.10, 0.26) and suggested, but did not confirm sustained unresponsiveness (RR = 0.29, 95% CI 0.08, 1.13). Only one study reported on disease-specific quality of life (QoL), which reported no comparative results between OIT and control group. Meta-analyses revealed that the risk of experiencing a systemic adverse reaction was higher in those receiving AIT, with a more marked increase in the risk of local adverse reactions. Sensitivity analysis excluding those studies judged to be at high risk of bias demonstrated the robustness of summary estimates of effectiveness and safety of AIT for food allergy. None of the studies reported data on health economic analyses. CONCLUSIONS: AIT may be effective in raising the threshold of reactivity to a range of foods in children with IgE-mediated food allergy whilst receiving (i.e. desensitization) and post-discontinuation of AIT. It is, however, associated with a modest increased risk in serious systemic adverse reactions and a substantial increase in minor local adverse reactions. More data are needed in relation to adults, long term effects, the impact on QoL and the cost-effectiveness of AIT.

Safety and predictors of adverse events during oral immunotherapy for milk allergy: severity of reaction at oral challenge, specific IgE and prick test.

BACKGROUND: Strict avoidance is the only accepted management for cow's milk (CM) allergy. CM oral immunotherapy (CM-OIT) is under investigation. OBJECTIVES: To evaluate long-term safety of CM-OIT. To identify clinical/immunological predictors of adverse events. METHODS: Prospective longitudinal epidemiological intervention study. CM-allergic children aged 5-18 underwent a Spanish-approved CM-OIT protocol without premedication. Clinical data, skin prick test (SPT) and specific IgE (sIgE) at baseline and 1 year after OIT were registered. All dose-related reactions, treatments needed and cofactors involved were recorded. Through survival analysis, we studied the cumulative probability of reactions resolution over time and clinical/immunological risk factors of reactions persistence. RESULTS: 81 children were recruited. Mean follow-up was 25 months. 95% of children suffered reactions, 91% of which affected a single organ. Reactions were heterogeneously distributed: (a) 60 children (75%) had occasional symptoms which ceased over time. 86% of them reached complete desensitization (200 mL). (b) 20 children (25%) suffered frequent (78% of total reactions), more severe and unpredictable reactions, which persisted during follow-up or led to withdrawal (6 cases). Reactions persistence was associated with a higher frequency and severity. Kaplan-Meier estimate revealed a cumulative probability of reactions resolution of 25% at 3 months (95% CI: 1.9-4.1) and 50% (95% CI: 6.1-9.9) at 8 months based on all patients. Cox proportional hazards multivariate regression model identified 3 variables (CM-sIgE ≥ 50 KU L(-1) , CM-SPT ≥ 9 mm and Sampson's severity grades 2, 3 and 4 at baseline food challenge) as independent risk factors of reactions persistence. The combination of 2 or 3 of these factors involved hazard ratios to develop persistent reactions of 2.26 (95% CI: 1.14-4.46; P = 0.019) and 6.06 (95% CI: 2.7-13.7; P < 0.001), respectively. CLINICAL IMPLICATIONS: CM-OIT was insufficiently safe in 25% of children. The above-mentioned clinical and immunological parameters would help clinicians to identify highly reactive patients before CM-OIT. In them, individualized schedules and premedication should be considered.