Prevalence and Severity of Food Allergies Among US Adults

IL-4-BATF signaling directly modulates IL-9 producing mucosal mast cell (MMC9) function in experimental food allergy

BACKGROUND

This study group has previously identified IL-9-producing mucosal mast cell (MMC9) as the primary source of IL-9 to drive intestinal mastocytosis and experimental IgE-mediated food allergy. However, the molecular mechanisms that regulate the expansion of MMC9s remain unknown.

OBJECTIVES

This study hypothesized that IL-4 regulates MMC9 development and MMC9-dependent experimental IgE-mediated food allergy.

METHODS

An epicutaneous sensitization model was used and bone marrow reconstitution experiments were performed to test the requirement of IL-4 receptor α (IL-4Rα) signaling on MMC9s in experimental IgE-mediated food allergy. Flow cytometric, bulk, and single-cell RNA-sequencing analyses on small intestine (SI) MMC9s were performed to illuminate MMC9 transcriptional signature and the effect of IL-4Rα signaling on MMC9 function. A bone marrow-derived MMC9 culture system was used to define IL-4-BATF signaling in MMC9 development.

RESULTS

Epicutaneous sensitization- and bone marrow reconstitution-based models of IgE-mediated food allergy revealed an IL-4 signaling-dependent cell-intrinsic effect on SI MMC9 accumulation and food allergy severity. RNA-sequencing analysis of SI-MMC9s identified 410 gene transcripts reciprocally regulated by IL-4 signaling, including Il9 and Batf. Insilico analyses identified a 3491-gene MMC9 transcriptional signature and identified 2 transcriptionally distinct SI MMC9 populations enriched for metabolic or inflammatory programs. Employing an in vitro MMC9-culture model system showed that generation of MMC9-like cells was induced by IL-4 and this was in part dependent on BATF.

CONCLUSIONS

IL-4Rα signaling directly modulates MMC9 function and exacerbation of experimental IgE-mediated food allergic reactions. IL-4Rα regulation of MMC9s is in part BATF-dependent and occurs via modulation of metabolic transcriptional programs.

Prevention of food allergy: can we stop the rise of IgE mediated food allergies?

PURPOSE OF REVIEW

Food allergy has become more prevalent in recent decades. Without a curative treatment for food allergy, prevention is key. Can we intervene and halt the food allergy epidemic?

RECENT FINDINGS

There are three main hypotheses to explain the rise in food allergy: the dual-allergen exposure hypothesis, the hygiene hypothesis and the vitamin D hypothesis. In a recent systematic review of randomized controlled trials, only introduction of allergenic foods, namely egg and peanut, in the diet at the time of weaning and avoidance of temporary supplementation with cow's milk formula in the first few days of life showed low to moderate evidence of a preventive effect.

SUMMARY

For primary prevention, introduction of allergenic foods at the time of weaning and avoidance of temporary supplementation with cow's milk formula in the first few days of life has been recommended. Introduction of foods once allergy has been excluded may be beneficial for sensitized subjects (secondary prevention). Once food allergy has been established, it is important to minimise complications (tertiary prevention) through allergen avoidance, timely treatment of allergic reactions, control of atopic co-morbidities and dietetic and psychological support, as appropriate. Immunomodulatory treatments can potentially be disease-modifying and require further research.

Advances in Food Allergy Treatment

Food allergies represent life-threatening diseases which are increasing in prevalence with no definitive treatments currently in place. Current treatments are no more than preventative avoidance and symptom management. Research within the field has focused on therapeutic developments to modify the immune response in allergen-specific and non-specific methods. This review of the advances made in treatments intends to cover methods such as oral immunotherapy, modified food protein vaccines as well as the use of alternative medicine. Thus, this review aims to inform and further extend discussion surrounding the potential clinical applications as well as novel routes for further research into an, as of yet, unsolved question.

Model of Walnut Allergy in CC027/GeniUnc Mice Recapitulates Key Features of Human Disease

Tree nut allergies affect 1% of the United States population, are often severe in nature and rarely outgrown. Despite the severity and prevalence, there are no FDA-approved treatments for tree nut allergy. Development of a therapeutic would be expedited by having a mouse model that mimics the human disease. We utilized the CC027/GeniUnc mouse strain, which was previously identified as an orally reactive model of peanut allergy, to develop a model of walnut allergy. Mice were sensitized with walnut and cholera toxin for 4 weeks and subsequently challenged by oral gavage. Blood samples were collected to measure serum IgE. Walnut-sensitized mice produced high levels of walnut-IgE and were cross-sensitized to pecan. Oral challenges with walnut resulted in severe anaphylaxis and accompanying allergic symptoms. Importantly, pecan challenges also led to severe allergic reactions, indicating cross-reactivity to pecan. Overall, this novel mouse model reproduces key characteristics of human walnut allergy, which provides a platform to develop novel therapies and better understand sensitization mechanisms.

Peanut protein acts as a TH2 adjuvant by inducing RALDH2 in human antigen-presenting cells

BACKGROUND

Peanut is a potent inducer of proallergenic T_H2 responses in susceptible individuals. Antigen-presenting cells (APCs) including dendritic cells and monocytes instruct naive T cells to differentiate into various effector cells, determining immune responses such as allergy and tolerance.

OBJECTIVE

We sought to detect peanut protein (PN)-induced changes in gene expression in human myeloid dendritic cells (mDCs) and monocytes, identify signaling receptors that mediate these changes, and assess how PN-induced genes in mDCs impact their ability to promote T-cell differentiation.

METHODS

mDCs, monocytes, and naive CD4⁺ T cells were isolated from blood bank donors and peanut-allergic patients. APCs were incubated with PN and other stimulants, and gene expression was measured using microarray and RT quantitative PCR. To assess T-cell differentiation, mDCs were cocultured with naive T_H cells.

RESULTS

PN induced a unique gene expression profile in mDCs, including the gene that encodes retinaldehyde dehydrogenase 2 (RALDH2), a rate-limiting enzyme in the retinoic acid (RA)-producing pathway. Stimulation of mDCs with PN also induced a 7-fold increase in the enzymatic activity of RALDH2. Blocking antibodies against Toll-like receptor (TLR)1/TLR2, as well as small interfering RNA targeting TLR1/TLR2, reduced the expression of RALDH2 in PN-stimulated APCs by 70%. Naive T_H cells cocultured with PN-stimulated mDCs showed an RA-dependent 4-fold increase in production of IL-5 and expression of integrin α₄β₇.

CONCLUSIONS

PN induces RALDH2 in human APCs by signaling through the TLR1/TLR2 heterodimer. This leads to production of RA, which acts on T_H cells to induce IL-5 and gut-homing integrin. RALDH2 induction by PN in APCs and RA-promoted T_H2 differentiation could be an important factor determining allergic responses to peanut.

Development of a Microfluidic Paper-Based Immunoassay for Rapid Detection of Allergic Protein in Foods

Food allergy affects up to 10% of the population, causing moderate to severe systemic symptoms and even death. Detecting allergens in food is the most critical and effective measure to reduce food allergy incidents, but the most commonly used kits, lateral flow immunoassay (LFI), are still relatively high in cost for the food industry. Microfluidic paper-based analytical devices (μPADs) demonstrate the potential to address this challenge by substituting the multiple parts/materials in LFI with solely (cellulose) paper as the platform. This study reports the development of a single-piece lateral flow μPAD and demonstrates its capability of detecting allergic protein in various food samples within a 15 min including sample preparation. A confined reagent deposition on the testing zone of the patterned paper was achieved by blade cutting. Surface modification of the cellulose was optimized to enable the complete release of recognizing conjugates and elimination of background noise. The geometry of patterns was optimized to meet the liquid sample's requirement in flow rate. This LFI-format μPAD can detect as low as 1 ppm ovalbumin in standard solution, 0.01% (w/w) egg white protein in spiked cake mix, and the egg content in other commercial food products. Much simpler fabrication procedures and a lower material cost are required by the μPAD than that by conventional LFIs. With the potential to scale up, this study provides an alternative food monitoring option to many sectors throughout the agri-food chain and contributes to improving food safety and public health.

Novel Allergen Discovery through Comprehensive De Novo Transcriptomic Analyses of Five Shrimp Species

Shellfish allergy affects 2% of the world's population and persists for life in most patients. The diagnosis of shellfish allergy, in particular shrimp, is challenging due to the similarity of allergenic proteins from other invertebrates. Despite the clinical importance of immunological cross-reactivity among shellfish species and between allergenic invertebrates such as dust mites, the underlying molecular basis is not well understood. Here we mine the complete transcriptome of five frequently consumed shrimp species to identify and compare allergens with all known allergen sources. The transcriptomes were assembled de novo, using Trinity, from raw RNA-Seq data of the whiteleg shrimp (Litopenaeus vannamei), black tiger shrimp (Penaeus monodon), banana shrimp (Fenneropenaeus merguiensis), king shrimp (Melicertus latisulcatus), and endeavour shrimp (Metapenaeus endeavouri). BLAST searching using the two major allergen databases, WHO/IUIS Allergen Nomenclature and AllergenOnline, successfully identified all seven known crustacean allergens. The analyses revealed up to 39 unreported allergens in the different shrimp species, including heat shock protein (HSP), alpha-tubulin, chymotrypsin, cyclophilin, beta-enolase, aldolase A, and glyceraldehyde-3-phosphate dehydrogenase (G3PD). Multiple sequence alignment (Clustal Omega) demonstrated high homology with allergens from other invertebrates including mites and cockroaches. This first transcriptomic analyses of allergens in a major food source provides a valuable resource for investigating shellfish allergens, comparing invertebrate allergens and future development of improved diagnostics for food allergy.

Consensus on DEfinition of Food Allergy SEverity (DEFASE): Protocol for a systematic review

Background and aims

The term “Food Allergy” refers to a complex global health problem with a wide spectrum of severity. However, a uniform definition of severe food allergy is currently missing. This systematic review is the preliminary step towards a state-of-the-art synopsis of the current evidence relating to the severity of IgE-mediated food allergy; it will inform attempts to develop a consensus to define food allergy severity by clinicians and other stakeholders.

Methods

We will undertake a systematic review, which will involve searching international biomedical databases for published studies. Studies will be independently screened against pre-defined eligibility criteria and critically appraised by established instruments. Data will be descriptively and, if possible and applicable, quantitatively synthesised.

Ethics and dissemination

This study does not require any specific ethical approval since it is a systematic review. We plan to report results from this systematic review in a peer reviewed journal. These results will be used to inform the development of an international consensus to define severe food allergy. Author's potential conflicts of interest are clearly stated.

PROSPERO registration number

CRD42020183103.

IgE and IgG Antibodies as Regulators of Mast Cell and Basophil Functions in Food Allergy

Food allergy is a major health issue, affecting the lives of 8% of U.S. children and their families. There is an urgent need to identify the environmental and endogenous signals that induce and sustain allergic responses to ingested allergens. Acute reactions to foods are triggered by the activation of mast cells and basophils, both of which release inflammatory mediators that lead to a range of clinical manifestations, including gastrointestinal, cutaneous, and respiratory reactions as well as systemic anaphylaxis. Both of these innate effector cell types express the high affinity IgE receptor, FcϵRI, on their surface and are armed for adaptive antigen recognition by very-tightly bound IgE antibodies which, when cross-linked by polyvalent allergen, trigger degranulation. These cells also express inhibitory receptors, including the IgG Fc receptor, FcγRIIb, that suppress their IgE-mediated activation. Recent studies have shown that natural resolution of food allergies is associated with increasing food-specific IgG levels. Furthermore, oral immunotherapy, the sequential administration of incrementally increasing doses of food allergen, is accompanied by the strong induction of allergen-specific IgG antibodies in both human subjects and murine models. These can deliver inhibitory signals via FcγRIIb that block IgE-induced immediate food reactions. In addition to their role in mediating immediate hypersensitivity reactions, mast cells and basophils serve separate but critical functions as adjuvants for type 2 immunity in food allergy. Mast cells and basophils, activated by IgE, are key sources of IL-4 that tilts the immune balance away from tolerance and towards type 2 immunity by promoting the induction of Th2 cells along with the innate effectors of type 2 immunity, ILC2s, while suppressing the development of regulatory T cells and driving their subversion to a pathogenic pro-Th2 phenotype. This adjuvant effect of mast cells and basophils is suppressed when inhibitory signals are delivered by IgG antibodies signaling via FcγRIIb. This review summarizes current understanding of the immunoregulatory effects of mast cells and basophils and how these functions are modulated by IgE and IgG antibodies. Understanding these pathways could provide important insights into innovative strategies for preventing and/or reversing food allergy in patients.

Traditional Chinese medicine for food allergy and eczema

OBJECTIVE

To summarize the recent evidence of traditional Chinese medicine (TCM) for food allergy and eczema.

DATA SOURCES

Published literature from PubMed database and abstract conference presentations.

STUDY SELECTIONS

Studies relevant to TCM for food allergy and eczema were included.

RESULTS

TCM is the main component of complementary and alternative medicine in the United States. Food Allergy Herbal Formula 2 (FAHF-2) (derived from the classical formula Wu Mei Wan) prevented systemic anaphylaxis in murine models and was found to have safety and preliminary immunomodulatory effects on T cells and basophils. The phase II trial of combined TCM with oral immunotherapy and omalizumab for multiple food allergy is ongoing. Retrospective practice-based evidence study revealed that comprehensive TCM therapy effectively prevented frequent and severe food anaphylaxis triggered by skin contact or protein inhalation. The traditional Japanese herbal medicine Kakkonto suppressed allergic diarrhea and decreased mast cells in intestinal mucosa in a murine model. The active compounds from TCM were found to have potent inhibition of immunoglobulin (Ig) E, mast cell activation, and proinflammatory cytokine or signaling pathway (tumor necrosis factor alpha, interleukin 8, NF-κB) suggesting value for both IgE and non-IgE-mediated food allergy. Triple TCM therapy including ingestion, bath, and cream markedly improved skin lesion, itching, and sleep loss in patients with corticosteroid dependent, recalcitrant, or topical steroid withdrawal. Xiao Feng San and Japanese and Korean formulas were found to have effectiveness in eczema. Furthermore, acupuncture reduced wheal size, skin itching, and basophil activation in atopic dermatitis. Moreover, TCM is generally safe.

CONCLUSION

TCM has potential as safe and effective therapy for food allergy and eczema. Further research is needed for botanical drug development and to further define the mechanisms of actions.

TRIAL REGISTRATION

FAHF-2: https://ichgcp.net/clinical-trials-registry/NCT00602160; ethyl acetate and butanol purified FAHF-2: https://clinicaltrials.gov/ct2/show/NCT02879006.

The Gut Microbiome and the Big Eight

Food allergies are increasing at an alarming rate, with 6.5% of the general population affected. It has been hypothesized that the increase in allergies stems from the “hygiene hypothesis”. The gut microbiome, a collection of microbiota and their genetic contents from the gastrointestinal tract, has been shown to play a part in the development of food allergies. The Food and Drug Administration requires all regulated food companies to clearly state an inclusion of the major, or “big eight” food allergens on packaging. This review is to provide information on the significant advancements related to the gut microbiome and each of the eight major food allergies individually. Establishment of causal connection between the microbiome and food allergies has uncovered novel mechanisms. New strategies are discussed to prevent future sensitization and reaction through novel treatments involving functional additives and dietary changes that target the microbiome.

Interdisciplinary Significance of Food-Related Adverse Reactions in Adulthood

Background: Adults frequently interpret food-associated adverse reactions as indicators of a food allergy. However, the public perception of food allergy may differ from a clinician's point of view. The prevalence of patient-reported food allergy tends to be higher than physician-confirmed cases. Dermatological manifestations (urticaria, pruritus, dermatitis, and edema) are frequently reported by patients. Objective: The aim of this study was to describe patient-reported symptoms related to suspected food allergies and particularly to characterize and highlight the volume of patients who visit Budapest allergy clinics with suspected food allergies. Methods: In this prospective study, adult (≥18 years) patients were examined at the Allergology Outpatient Unit of the Dept. of Dermatology, Venereology, and Dermatooncology, Semmelweis University, Budapest. The examination included a detailed medical history; physical examination; and when necessary the measurement of allergen-specific serum immunoglobulin E (IgE) levels. Results: Data from 501 patients (393 women, 108 men) were analyzed. Intolerance to dietary biogenic amines occurred in 250 cases (250/501, 50%). Oral allergy syndrome was confirmed in 71 patients (71/501, 14%). Allergy to food preservatives was diagnosed in 14 (14/501, 3%) cases by a dermatologist-allergist specialist. Five individuals (5/501, 1%) were diagnosed with IgE-mediated food allergy. In some cases (28/501, 6%), edema-inducing/enhancing side effects of drugs were observed which patients had misattributed to various foods. Among the food groups considered to be provoking factors, the most frequently mentioned were fruits (198/501, 40%), milk/dairy products (174/501, 35%), and nuts/oilseeds (144/501, 29%). Overwhelmingly, urticaria (47%) was the most common dermatological diagnosis, followed by dermatitis (20%) and allergic contact dermatitis (8%). Conclusion: Improvement is needed in food allergy, food intolerance, and general nutritional knowledge among the general public. According to our data, perceived/self-reported food allergies were overestimated by adults when compared against physician-confirmed food allergies; however, other diseases potentially responsible for food-related problems were underestimated. The prevalence of oral allergy syndrome was high in the cohort. Intolerance to dietary biogenic amines was common, and although the role of dietary histamine and biogenic amine is not entirely understood in eliciting patients' symptoms, improvements in complaints were reported during the control visits.

Nutritional management of food allergies

Food allergy is a significant public health concern, with a rising prevalence. Elimination diets remain the cornerstone of food allergy management, and they are not without nutritional risk. Children who avoid nutritionally important foods, such as milk or multiple foods allergens, may be at greater risk. Even adults with food allergies may encounter challenges to meet current recommended dietary guidelines for health and reduced risk of chronic disease. The type of food allergy disorder will also impact nutritional risk. A food allergy affects food choices, nutritional intake, and health; therefore, guidance to provide nutritionally appropriate substitutes within the context of the elimination diet is invaluable.

Plant Proteins: Assessing Their Nutritional Quality and Effects on Health and Physical Function

Consumer demand for plant protein-based products is high and expected to grow considerably in the next decade. Factors contributing to the rise in popularity of plant proteins include: (1) potential health benefits associated with increased intake of plant-based diets; (2) consumer concerns regarding adverse health effects of consuming diets high in animal protein (e.g., increased saturated fat); (3) increased consumer recognition of the need to improve the environmental sustainability of food production; (4) ethical issues regarding the treatment of animals; and (5) general consumer view of protein as a "positive" nutrient (more is better). While there are health and physical function benefits of diets higher in plant-based protein, the nutritional quality of plant proteins may be inferior in some respects relative to animal proteins. This review highlights the nutritional quality of plant proteins and strategies for wisely using them to meet amino acid requirements. In addition, a summary of studies evaluating the potential benefits of plant proteins for both health and physical function is provided. Finally, potential safety issues associated with increased intake of plant proteins are addressed.

An electrochemical molecularly imprinted polymer sensor for rapid and selective food allergen detection

Food allergies are a serious and rising public health concern. The potentially fatal consequence of food allergies makes managing them costly and anxiety-inducing. Rapid, on-site detection of allergenic ingredients in foods would greatly improve the health and quality of life of food allergy sufferers. This work demonstrates the feasibility of such a device using molecularly imprinted polymers (MIPs). The MIP sensor can detect allergenic soy markers at concentrations as low as 100 parts-per-billion, two orders of magnitude below clinically relevant thresholds, in both controlled and complex food samples. Sensor performance was qualitatively validated with commercially available soy allergen detection lateral flow devices (LFDs). The outcome of this application will address a long-standing analytical challenge to achieving fast, cost-effective, and scalable methods for direct detection of allergen tracers in food analysis.

A Systematic Review of Food Allergy: Nanobiosensor and Food Allergen Detection

Several individuals will experience accidental exposure to an allergen. In this sense, the industry has invested in the processes of removing allergenic compounds in food. However, accidental exposure to allergenic proteins can result from allergenic substances not specified on labels. Analysis of allergenic foods is involved in methods based on immunological, genetic, and mass spectrometry. The traditional methods have some limitations, such as high cost. In recent years, biosensor and nanoparticles combined have emerged as sensitive, selective, low-cost, and time-consuming techniques that can replace classic techniques. Nevertheless, each nanomaterial has shown a different potential to specific allergens or classes. This review used Preferred Reporting Items for Systematic Reviews and the Meta-Analysis guidelines (PRISMA) to approach these issues. A total of 104 articles were retrieved from a standardized search on three databases (PubMed, Scopus and Web of Science). The systematic review article is organized by the category of allergen detection and nanoparticle detection. This review addresses the relevant biosensors and nanoparticles as gold, carbon, graphene, quantum dots to allergen protein detection. Among the selected articles it was possible to notice a greater potential application on the allergic proteins Ah, in peanuts and gold nanoparticle-base as a biosensor. We envision that in our review, the association between biosensor and nanoparticles has shown promise in the analysis of allergenic proteins present in different food samples.

Food allergies and allergens: Characterization and perceptions among diagnosed food allergic individuals in Lebanon

Background

The aim of our study was to assess the knowledge, practices, and attitudes towards food allergens and allergies among diagnosed food allergic individuals in Lebanon.

Methods

Seventy diagnosed participants were recruited after reaching out to all the allergists of the country. They completed in person or over the phone a comprehensive valid questionnaire composed of 49 questions.

Results

Wheat was reported as top food allergen (15.7%), while itchy skin and rash were the most reported symptoms (71.4% and 68.6%, respectively). Only 34 (48.6%) of participants indicated they carry medications, 58 (70.7%) were diagnosed using blood test, and 22 (31.4%) stated that they are very knowledgeable on the topic. In terms of knowledge, participants scored on average 84.2 ± 11.5%. In terms of best practices, participants scored on average 47.8 ± 28.3%. Having a health related educational background increased significantly (p < 0.05) both knowledge and best practices scores, while age and gender did not have an effect.

Conclusions

Our results highlight the importance of organizing ongoing educational initiatives and emphasize the need to lobby policy makers to making allergen-warning labels obligatory in the country.

Mapping and Modeling of Discussions Related to Gastrointestinal Discomfort in French-Speaking Online Forums: Results of a 15-Year Retrospective Infodemiology Study

BACKGROUND

Gastrointestinal (GI) discomfort is prevalent and known to be associated with impaired quality of life. Real-world information on factors of GI discomfort and solutions used by people is, however, limited. Social media, including online forums, have been considered a new source of information to examine the health of populations in real-life settings.

OBJECTIVE

The aims of this retrospective infodemiology study are to identify discussion topics, characterize users, and identify perceived determinants of GI discomfort in web-based messages posted by users of French social media.

METHODS

Messages related to GI discomfort posted between January 2003 and August 2018 were extracted from 14 French-speaking general and specialized publicly available online forums. Extracted messages were cleaned and deidentified. Relevant medical concepts were determined on the basis of the Medical Dictionary for Regulatory Activities and vernacular terms. The identification of discussion topics was carried out by using a correlated topic model on the basis of the latent Dirichlet allocation. A nonsupervised clustering algorithm was applied to cluster forum users according to the reported symptoms of GI discomfort, discussion topics, and activity on online forums. Users' age and gender were determined by linear regression and application of a support vector machine, respectively, to characterize the identified clusters according to demographic parameters. Perceived factors of GI discomfort were classified by a combined method on the basis of syntactic analysis to identify messages with causality terms and a second topic modeling in a relevant segment of phrases.

RESULTS

A total of 198,866 messages associated with GI discomfort were included in the analysis corpus after extraction and cleaning. These messages were posted by 36,989 separate web users, most of them being women younger than 40 years. Everyday life, diet, digestion, abdominal pain, impact on the quality of life, and tips to manage stress were among the most discussed topics. Segmentation of users identified 5 clusters corresponding to chronic and acute GI concerns. Diet topic was associated with each cluster, and stress was strongly associated with abdominal pain. Psychological factors, food, and allergens were perceived as the main causes of GI discomfort by web users.

CONCLUSIONS

GI discomfort is actively discussed by web users. This study reveals a complex relationship between food, stress, and GI discomfort. Our approach has shown that identifying web-based discussion topics associated with GI discomfort and its perceived factors is feasible and can serve as a complementary source of real-world evidence for caregivers.

Epicutaneously sensitized food-induced anaphylaxis is ameliorated with "oral tolerance" to antigen

Food allergy is an antigen-specific immunological adverse reaction after exposure to a given food. Multiple clinical studies showed that oral immunotherapy (OIT) is effective for the prevention and treatment for food allergy that is developed in infants and children. However, the effectiveness of OIT for epicutaneously sensitized food allergy remains unclear. Previously, we established a mouse model of epicutaneous-sensitized food allergy. In this model, systemic allergic reaction including intestinal and skin symptoms, such as anaphylaxis, was observed. We treated this model with OIT in two ways (OIT before sensitization or OIT during the sensitization phase) and evaluated the preventive effect of both methods. OIT before sensitization significantly ameliorated mast cell degranulation in sensitized skin, but there was no decrease in rectal temperatures or in mast cell degranulation in the jejunum. However, OIT administered during the sensitization phase significantly ameliorated the decrease in rectal temperature and mast cell degranulation in the skin and jejunum. OIT before sensitization increased the regulatory T cells in mesenteric lymph node (MLN), but not in the spleen, and it reduced antigen-specific IgG, but not IgE, production compared with the non-OIT control. However, OIT during sensitization caused a greater increase in regulatory T cells in both the MLN and spleen and reduced antigen-specific IgE and IgG generation compared with the non-OIT control group. Thus, OIT during the sensitization phase was effective for the prevention of epicutaneous-sensitized food allergy.

APPEAL-1: A pan-European survey of patient/caregiver perceptions of peanut allergy management

BACKGROUND

Peanut allergy (PA) is associated with marked quality-of-life (QoL) impairment. However, data are lacking on the experience and impact of living with PA from the perspectives of persons with PA (PwPA) and their caregivers. Allergy to Peanuts imPacting Emotions And Life study 1 (APPEAL-1) was a pan-European survey investigating these perspectives. This first of two articles reports clinical characteristics of PwPA and PA management practices.

METHODS

APPEAL-1 was a quantitative, online survey conducted in eight European countries, developed by eight representatives of patient advocacy groups and five healthcare professionals and researchers. Eligible participants included adults with PA and parents/caregivers of PwPA who responded by self-report and provided proxy-report for the PwPA under their care. Data were summarized using nonweighted descriptive statistics.

RESULTS

Of 1846 completed/analysed questionnaires, 528 were from adults with PA (self-report); 437 by proxy for children with PA (34 aged 0-3 years, 287 aged 4-12 years, 116 aged 13-17 years) and 881 from parents/caregivers (self-report). Of PwPA (N = 965), 95% reported diagnosis by healthcare professionals, mostly by clinical history and peanut-specific allergy testing. Rates of allergic rhinitis, asthma and other food allergies in PwPA were 50%, 42% and 79%, respectively. Only 31% of PwPA received HCP advice/support following their worst allergic reaction, and 28% had not been prescribed an adrenaline auto-injector. Results were similar by country but varied by age group.

CONCLUSIONS

The APPEAL-1 findings contribute to greater understanding of PA impact on PwPA, caregivers and family members and the need for improved PA management across Europe.

Effect of structural stability on endolysosomal degradation and T-cell reactivity of major shrimp allergen tropomyosin

BACKGROUND

Tropomyosins are highly conserved proteins, an attribute that forms the molecular basis for their IgE antibody cross-reactivity. Despite sequence similarities, their allergenicity varies greatly between ingested and inhaled invertebrate sources. In this study, we investigated the relationship between the structural stability of different tropomyosins, their endolysosomal degradation patterns, and T-cell reactivity.

METHODS

We investigated the differences between four tropomyosins-the major shrimp allergen Pen m 1 and the minor allergens Der p 10 (dust mite), Bla g 7 (cockroach), and Ani s 3 (fish parasite)-in terms of IgE binding, structural stability, endolysosomal degradation and subsequent peptide generation, and T-cell cross-reactivity in a BALB/c murine model.

RESULTS

Tropomyosins displayed different melting temperatures, which did not correlate with amino acid sequence similarities. Endolysosomal degradation experiments demonstrated differential proteolytic digestion, as a function of thermal stability, generating different peptide repertoires. Pen m 1 (Tm 42°C) and Der p 10 (Tm 44°C) elicited similar patterns of endolysosomal degradation, but not Bla g 7 (Tm 63°C) or Ani s 3 (Tm 33°C). Pen m 1-specific T-cell clones, with specificity for regions highly conserved in all four tropomyosins, proliferated weakly to Der p 10, but did not proliferate to Bla g 7 and Ani s 3, indicating lack of T-cell epitope cross-reactivity.

CONCLUSIONS

Tropomyosin T-cell cross-reactivity, unlike IgE cross-reactivity, is dependent on structural stability rather than amino acid sequence similarity. These findings contribute to our understanding of cross-sensitization among different invertebrates and design of suitable T-cell peptide-based immunotherapies for shrimp and related allergies.

Implementation of the Addendum Guidelines for Peanut Allergy Prevention by US allergists, a survey conducted by the NIAID, in collaboration with the AAAAI

BACKGROUND

In 2017, the Addendum Guidelines for the Prevention of Peanut Allergy were published with recommendations on early introduction of peanut-containing foods based on infants' clinical history.

OBJECTIVE

We sought to conduct a nationwide US survey to assess Guidelines implementation among allergists and immunologists who manage infants for food allergy.

METHODS

Survey invitations were delivered to 3281 nonretired, US members of the American Academy of Asthma, Allergy & Immunology, board certified in allergy and immunology. The survey assessed awareness and implementation of the Guidelines and barriers to implementation. Descriptive statistics were generated.

RESULTS

Twenty-nine percent (946 of 3281) of surveyed allergists/immunologists responded, and 87.1% (825 of 946) of responders met eligibility criteria. Among eligible responders, 97.1% were aware of the Guidelines. Of these, 64.5% reported full implementation of the Guidelines as published, 34.4% reported partial implementation, and 1.1% reported using none of the Guidelines. Barriers to Guidelines use included parental (47.6%) and self (21.8%) concerns about allergic reactions, lack of referrals (33.6%), parents uninterested in early feeding (28.2%), and lack of clinic time (20.9%). The 2 most common deviations from the Guidelines were considering additional factors not specified in the Guidelines such as family history (50.2%) and conducting skin prick testing in non-high-risk children (43.9%). Of respondents using the Guidelines, 45.7% indicated they needed more education or training.

CONCLUSIONS

Essentially all allergists/immunologists who responded to the survey reported full or partial Guidelines implementation. Parental concerns and lack of referrals are major identifiable barriers. Improved Guidelines messaging to parents and referring physicians is warranted.

Ovomucoid epitope-specific repertoire of IgE, IgG4 , IgG1 , IgA1 , and IgD antibodies in egg-allergic children

BACKGROUND

Egg-white ovomucoid, that is, Gal d 1, is associated with IgE-mediated allergic reactions in most egg-allergic children. Epitope-specific IgE levels have been correlated with the severity of egg allergy, while emerging evidence suggests that other antibody isotypes (IgG₁ , IgG₄ , IgA, and IgD) may have a protective function; yet, their epitope-specific repertoires and associations with atopic comorbidities have not been studied.

METHODS

Bead-based epitope assay (BBEA) was used to quantitate the levels of epitope-specific (es)IgA, esIgE, esIgD, esIgG₁ , and esIgG₄ antibodies directed at 58 (15-mer) overlapping peptides, covering the entire sequence of ovomucoid, in plasma of 38 egg-allergic and 6 atopic children. Intraclass correlation (ICC) and coefficient of variation (CV) were used for the reliability assessment. The relationships across esIgs were evaluated using network analysis; linear and logistic regressions were used to compare groups based on egg allergy status and comorbidities.

RESULTS

BBEA had high reliability (ICC >0.75) and low variability (CV <20%) and could detect known IgE-binding epitopes. Egg-allergic children had lower esIgA₁ (P = .010) and esIgG₁ (P = .016) and higher esIgE (P < .001) and esIgD (P = .015) levels compared to the atopic controls. Interestingly, within the allergic group, children with higher esIgD had decreased odds of anaphylactic reactions (OR =0.48, P = .038). Network analysis identified most associations between esIgE with either esIgG₄ or esIgD; indicating that IgE-secreting plasma cells could originate from either sequential isotype switch from antigen-experienced intermediate isotypes or directly from the IgD⁺ B cells.

CONCLUSIONS

Collectively, these data point toward a contribution of epitope-specific antibody repertoires to the pathogenesis of egg allergy.

Transcriptional frameshifts contribute to protein allergenicity

Transcription infidelity (TI) is a mechanism that increases RNA and protein diversity. We found that single-base omissions (i.e., gaps) occurred at significantly higher rates in the RNA of highly allergenic legumes. Transcripts from peanut, soybean, sesame, and mite allergens contained a higher density of gaps than those of nonallergens. Allergen transcripts translate into proteins with a cationic carboxy terminus depleted in hydrophobic residues. In mice, recombinant TI variants of the peanut allergen Ara h 2, but not the canonical allergen itself, induced, without adjuvant, the production of anaphylactogenic specific IgE (sIgE), binding to linear epitopes on both canonical and TI segments of the TI variants. The removal of cationic proteins from bovine lactoserum markedly reduced its capacity to induce sIgE. In peanut-allergic children, the sIgE reactivity was directed toward both canonical and TI segments of Ara h 2 variants. We discovered 2 peanut allergens, which we believe to be previously unreported, because of their RNA-DNA divergence gap patterns and TI peptide amino acid composition. Finally, we showed that the sIgE of children with IgE-negative milk allergy targeted cationic proteins in lactoserum. We propose that it is not the canonical allergens, but their TI variants, that initiate sIgE isotype switching, while both canonical and TI variants elicit clinical allergic reactions.

Almond allergens: update and perspective on identification and characterization

Almond (Prunus dulcis) is not only widely used as a human food as a result of its flavor, nutrients, and health benefits, but it is also one of the most likely tree nuts to trigger allergies. Almond allergens, however, have not been studied as extensively as those of peanuts and other selected tree nuts. This review provides an update of the molecular properties of almond allergens to clarify some confusion about the identities of almond allergens and our perspective on characterizing putative almond allergens. At present, the following almond allergens have been designated by the World Health Organization/International Union of Immunological Societies Allergen Nomenclature Sub-Committee: Pru du 3 (a non-specific lipid transfer protein 1, nsLTP1), Pru du 4 (a profilin), Pru du 5 (60S acidic ribosomal protein 2), Pru du 6 (an 11S legumin known as prunin) and Pru du 8 (an antimicrobial protein with cC3C repeats). Besides, almond vicilin and almond γ-conglutin have been identified as food allergens, although further characterization of these allergens is still of interest. In addition, almond 2S albumin was reported as a food allergen as a result of the misidentification of Pru du 8. Two more almond proteins have been called allergens based on their sequence homology with known food allergens and their 'membership' in relevant protein families that contain allergens in many species. These include the pathogenesis related-10 protein (referred to as Pru du 1) and the thaumatin-like protein (referred to as Pru du 2). Almonds thus have five known food allergens and five more likely ones that need to be investigated further. Published 2020. This article is a U.S. Government work and is in the public domain in the USA.

Adult-onset IgE-mediated food allergy at a Winnipeg allergy clinic: a case series

BACKGROUND

It is a putatively understood phenomenon that the overall prevalence of allergic disease has been increasing in recent decades-particularly in industrialized nations. Despite this, there is a relative scarcity of data concerning the development of food-related allergic disease in the adult population. In addition, the paucity of data as it pertains to the Canadian population is particularly marked when compared to other nations. We sought to determine common culprit foods and the reactions they elicited in a series of 14 patients seen in the Winnipeg allergy and immunology clinic.

METHODS

We conducted a retrospective review of patients identified by academic allergists in Winnipeg, Manitoba as fitting criteria for adult-onset IgE-mediated food allergy from May 2018-July 2020. We included patients with IgE-mediated symptoms, including the pollen-food syndrome which developed at the age of 16 or later. We collected data regarding the food which induced the reaction, what the reaction was, and any concomitant atopic disease.

RESULTS

The most common culprit food identified was shellfish, followed by finfish, pollen-food syndrome, and wheat/flour. The most common reaction experienced was anaphylaxis, followed by food-dependent exercise-induced anaphylaxis and isolated (muco)cutaneous symptoms. With regard to concomitant atopic disease, allergic rhinitis/rhinoconjunctivitis stood out as the most prevalent.

CONCLUSIONS

Adult-onset food allergy-particularly with resultant anaphylaxis-is an important phenomenon to recognize, even when patients have previously tolerated the food in question.

Understanding Precautionary Allergen Labeling (PAL) Preferences Among Food Allergy Stakeholders

BACKGROUND

Food allergy (FA) is an increasing public health concern in the United States, affecting approximately 8% of children and 11% of adults. The United States currently lacks clear requirements for the use of precautionary allergen labeling (PAL) on packaged foods, such as "may contain" or "made on shared equipment." This lack of specific governmental policy results in inconsistent labeling practices and confusion.

OBJECTIVE

This study aimed to understand current knowledge and preferences for PAL statements among FA stakeholders.

METHODS

A cross-sectional survey was sent to FA stakeholders. Descriptive statistics and associations from logistic regressions were used to assess respondents' knowledge of PAL policy, shopping habits, and preferences around PAL.

RESULTS

Of 3008 respondents, 24.2% were able to correctly answer 4 questions surrounding PAL policies. When asked about their shopping habits, the majority of respondents never purchase products with a "May contain traces of allergen" label (85.5%) in comparison with never purchasing products with a "Good manufacturing practices used to segregate ingredients in a facility that also processes allergen" label (35.0%). Their top preferences for a PAL statement were "Not suitable for people with 'blank' allergy" (29.3%) and "May contain" (22.1%). Health care provider discussions around PAL varied and were strongly associated with purchasing behaviors.

CONCLUSIONS

These results suggest that FA consumers are not aware of PAL policies and make decisions based on the words in the PAL. They prefer having clearer, more specific, and consistent labeling on products, indicating that explicit PAL policies are needed to allow customers to easily identify safe foods.

Detection of specific IgE against linear epitopes from Gal d 1 has additional value in diagnosing hen's egg allergy in adults

Background

Although hen's egg allergy is more prevalent in children, up to 0.6% of adults from different European countries suffer from a persistent or newly onset hen's egg allergy, making accurate diagnosis in adults necessary. However, sensitization to hen's egg extracts, components and linear epitopes is solely studied in children.

Methods

Hen's egg allergic (n = 16) and tolerant (n = 19) adults were selected by sensitization towards recombinant components rGal d 1 and/or 3. Sensitization profiles towards egg white and yolk extract and the native components Gal d 1, 2, 3 and 4 were respectively evaluated with the ImmunoCAP or the EUROLINE system. Characterization of linear epitopes was performed with a peptide microarray containing 15mer peptides representing the entire sequence of mature Gal d 1 and 3.

Results

Overall, sIgE titres against hen's egg extracts and single components overlapped largely between allergic and tolerant adults. Although the median sIgE/sIgG4 ratio to Gal d 1 was increased in allergic adults, the range was comparable between both groups. Clinically relevant sensitization to Gal d 1 was confirmed by sIgE‐binding to the linear epitopes aa30‐41, aa39‐50 or aa84‐95 in 6/13 allergic adults, mainly suffering from objective symptoms. In comparison, these epitopes were recognized by 1/15 tolerant patient. Only a few linear epitopes were detected for Gal d 3, suggesting a greater importance of conformational epitopes for the recognition of Gal d 3.

Conclusion and Clinical Relevance

Specific IgE‐binding to linear epitopes of Gal d 1 is highly specific in identifying hen's egg allergic adults with objective symptoms.

The Global Rise and the Complexity of Sesame Allergy: Prime Time to Regulate Sesame in the United States of America?

Sesame allergy is a life-threatening disease that has been growing globally with poorly understood mechanisms. To protect sensitive consumers, sesame is regulated in many countries. There were four research goals for this work on sesame allergy: (i) to map the timeline, and the extent of its global rise; (ii) to dissect the complexity of the disease, and its mechanisms; (iii) to analyze the global regulation of sesame; and (iv) to map the directions for future research and regulation. We performed a literature search on PubMed and Google Scholar, using combinations of key words and analyzed the output. Regulatory information was obtained from the government agencies. Information relevant to the above goals was used to make interpretations. We found that: (i) the reports appeared first in 1950s, and then rapidly rose globally from 1990s; (ii) sesame contains protein and lipid allergens, a unique feature not found in other allergenic foods; (iii) it is linked to five types of diseases with understudied mechanisms; and (iv) it is a regulated allergen in 32 advanced countries excluding the USA. We also provide directions for filling gaps in the research and identify implications of possible regulation of sesame in the USA.

Oral immunotherapy for peanut allergy: The con argument

Background

In some countries of the world, peanut allergy represents an important source of anaphylactic reactions. Traditionally treated with the avoidance of responsible allergens, this condition can also be targeted by oral peanut immunotherapy.

Methods

In this study, we review the beneficial and side effects of currently available forms of peanut oral immunotherapy (POIT). We report the discussions resulting from the publication of a meta-analysis that brought to light the downsides of oral immunotherapy for peanuts.

Results

In some clinical situations, the risk-benefit ratio can favor peanut oral immunotherapy over avoidance. In many other situations, this is not the case. The decision must be based on the values and preferences of clinicians and patients. Those not ready to accept serious adverse effects from POIT are likely to continue the elimination diet; those motivated to achieving desensitization, and prepared to accept serious adverse effects, may choose to undergo POIT.

Conclusions

Without being prejudiced against peanut oral immunotherapy, we indicate the possible evolution of treatment for this condition is in a rapidly evolving broader scenario. Among the future options, sublingual immunotherapy, parenteral immunotherapy with modified allergens, transcutaneous immunotherapy, and the use of biologics will become important options.

Oral immunotherapy for peanut allergy: The pro argument

Food allergy (FA) is a growing public health problem with personal, social, nutritional, and economic consequences. In the United States, it is estimated that 8% of children and 10.8% of adults have food allergies. Allergies to peanuts are particularly worrisome as unlike allergies to other allergenic foods, such as milk and egg, which are commonly outgrown by 5 or 10 years of age, 80% of peanut allergies persist into adulthood. The first drug for peanut allergy, Palforzia, was approved by the US Food and Drug Administration (FDA) in January 2020. For other food allergies, the current standard of care for the management of FA is suboptimal and is limited to dietary elimination of the offending allergen, vigilance against accidental ingestion, and treatment of allergic reactions with antihistamines and epinephrine. However, dietary avoidance can be challenging, and it is estimated that approximately 40% of patients with food allergies report at least one food allergy-related emergency department in their lifetime. Reactions, even from minimal exposures, can be life-threatening.

Oral immunotherapy (OIT) has been the best researched therapeutic approach for treating FA over the last decade, with clinical trials investigating its efficacy, safety, and ability to improve participants' quality of life (QoL). A number of studies and meta-analyses have shown that OIT treatment is effective in raising the threshold of reactivity to peanuts and other foods in addition to producing a measurable serum immune response to such therapy. Although OIT-related adverse events (AEs) are common during treatment, serious reactions are rare. In fact, while the majority of patients experience AEs related to dosing, most continue daily dosing in hopes of achieving protection against the culprit food. Moreover, the majority of participants report improvement of QoL after OIT and are positive about undergoing OIT. These results show patients’ commitment to OIT and their optimism regarding the benefits of treatment. As a first step in therapeutic options to protect from reactions to unintentional ingestion of allergenic foods, and importantly, to address the many psychosocial aspects of living with FA, OIT shows promise. Future research will focus on identifying optimal OIT regimens that maintain protection after therapy and allow for regular food consumption without allergic symptoms. Education and informed shared decision making between patients and providers are essential in optimizing current therapy regimens.

Three questions for identifying chemically intolerant individuals in clinical and epidemiological populations: The Brief Environmental Exposure and Sensitivity Inventory (BREESI)

The Quick Environmental Exposure and Sensitivity Inventory (QEESI) is a validated questionnaire used worldwide to assess intolerances to chemicals, foods, and drugs, and has emerged as the gold standard for assessing chemical intolerance (CI). Despite a reported prevalence of 8–33%, epidemiological studies and routine primary care clinics rarely assess CI. To help address this gap, we developed the Brief Environmental Exposure and Sensitivity Inventory (BREESI)—a 3-item CI screening tool. We tested the BREESI’s potential to predict whether an individual is likely to be classified as chemically intolerant if administered the 50-item QEESI. We recruited 293 participants from a university-based primary care clinic and through online participation. The statistical sensitivity, specificity, and positive and negative predictive values of the BREESI were calculated against the validated QEESI. Ninety percent (90%) of participants answering “yes” to all three items on the BREESI fit the QEESI criteria for being very suggestive of CI based upon their chemical intolerance and symptom scores (positive predictive value = 90%). For participants endorsing two items, 93% were classified as either very suggestive (39%) or suggestive (54%) of CI (positive predictive value = 87%). Of those endorsing only one item, 13% were classified as very suggestive of CI, and 70% as suggestive. Of those answering “No” to all of the BREESI items, 95% were classified as not suggestive of CI (i.e., negative predictive value = 95%). The BREESI is a versatile screening tool for assessing potential CI useful for clinical and epidemiological applications, based upon individuals’ past adverse responses in a variety of settings. Just as health care professionals routinely inquire about latex allergy to prevent adverse reactions, the BREESI provides an essential screen for CI. Together, the BREESI and QEESI provide new diagnostic tools that may help predict and prevent future adverse reactions to chemicals, foods, and drugs.

Cell-Based Functional IgE Assays Are Superior to Conventional Allergy Tests for Shrimp Allergy Diagnosis

BACKGROUND

The diagnosis of shellfish allergy currently relies on patient history, skin prick test (SPT), and serum specific IgE (sIgE) quantification. These methods lack sufficient diagnostic accuracy, whereas the gold standard of oral food challenges is risky and burdensome. Markers of reactivity and severity of allergic reactions to shellfish will improve clinical care of these patients.

OBJECTIVES

This study compared the diagnostic performance of SPT, sIgE, basophil activation test (BAT), and IgE crosslinking-induced luciferase expression (EXiLE) test for shrimp allergy.

METHODS

Thirty-five subjects with documented history of shrimp allergic reactions were recruited and grouped according to results of double-blind, placebo-controlled food challenge (DBPCFC). In addition to routine diagnostics, BAT (Flow CAST) and EXiLE test with shrimp extract and tropomyosin were performed.

RESULTS

Of 35 subjects, 15 were shrimp allergic with pruritus, urticaria, and itchy mouth on DBPCFC, whereas 20 were tolerant to shrimp. Tropomyosin only accounted for 53.3% of sensitization among subjects with challenge-proven shrimp allergy. BAT using shrimp extract as stimulant showed the highest area under curve value (0.88), Youden Index (0.81), likelihood ratio (14.73), odds ratio (104), and variable importance (4.27) when compared with other assays and tropomyosin diagnosis. Results of BAT significantly correlated with those of EXiLE (r = 0.664, P < .0001).

CONCLUSIONS

BAT is a more accurate diagnostic marker for shrimp allergy than SPT and shrimp sIgE, whereas the EXiLE test based on an IgE crosslinking assay is a good alternative to BAT. Tropomyosin may not be the most important shrimp allergen in Chinese, which warrants further investigation to search for other major allergens and diagnostic markers.

Mites, ticks, anaphylaxis and allergy: The Acari hypothesis

Anaphylaxis is a poorly understood immune process in which a Th2-/IgE-mediated adaptive response commandeers cellular machinery, typically reserved for defense against multicellular ectoparasites, to activate against otherwise benign molecules. Its clinical manifestations consist of rapid pathophysiological reflexes that target epithelial surfaces. The galactose-α-1,3-galactose hypersensitivity response is a compelling model of anaphylaxis for which causation has been demonstrated. At the core of the model, a tick bite sensitizes a recipient to a tick foodstuff. As proposed herein, the model likely informs on the origin of all allergic inflammation; namely, allergy is not intended to protect against seemingly harmless and irrelevant materials, but is, instead, intended to rid epithelial surfaces of pathogen-bearing Acari, i.e., mites and ticks. The demonstrated adjuvant activity of acarian gastrointestinal secretions, when paired with the polyphagous diet of mites, renders acarians eminently suited to accounting, mechanistically, for many, if not all, human allergies.

Development of a screening questionnaire for the study of food allergy in adults

Background & aims

As far as we know, no screening questionnaire has been developed and validated for identification of adverse food reactions in Portuguese-speaking adults, as an initial approach towards the investigation of cases of possible food allergy. Thus, the objective of this study was to develop and validate a screening questionnaire of food allergy in adult Portuguese-speaking patients.

Methods

This was a multicentre, cross-sectional study using a simple random sample of 186 adults between 18 and 82 years old from various parts of the centre of Portugal. Intelligibility of the questionnaire was first assessed in 24 patients with confirmed IgE- or non-IgE-mediated food allergy, and in 24 volunteers without food allergies. The 17-item questionnaire was subsequently applied by phone to 78 food allergic patients (66 IgE-mediated and 12 non-IgE mediated) and to 60 non-food allergic volunteers, with subsequent reassessment (re-test). Face and content validity, intelligibility, construct validity, and test-retest reliability (temporal stability) were analysed.

Results

Face and content validity allowed item reduction from 30 to 17 items with adequate content validity index >0.78. Construct validity was confirmed in the 66 confirmed IgE-mediated food allergic patients, 12 non-IgE-mediated food allergic patients, and 60 non-allergic patients. Test-Retest Reliability (general temporal stability) of the test had a Spearman correlation coefficient value of 0.845 for the retest. Cohen's Kappa values for the relevant questions were greater than 0.890 for almost all items. No differences were found when sex, age, and volunteers' recruitment origin were analysed. An inverse relationship was found between reliability and retest time interval.

Conclusions

Due to the quick and easy implementation, confirmation of face, content and construct validity as well as high temporal reproducibility, this screening questionnaire may be a useful study tool for an initial approach to detection of food allergies in adults.

Diagnosis and management of anaphylaxis

Anaphylaxis is a serious allergic reaction that is rapid in onset and may be life threatening. An informal review of the literature was performed in a nonsystematic way for this article. Key published work was identified and included. The incidence and prevalence of anaphylaxis have increased over time. Anaphylaxis is unpredictable and can be the result of various allergic triggers, including food, insect venom, and medication. In children, the most frequent trigger is food. The diagnosis is based on clinical criteria. After confirmation of the relevant allergen trigger, prevention occurs through strict avoidance of the allergen and optimal management of existing comorbidities. Patients with anaphylaxis require immediate assessment and treatment. The management of a patient with anaphylaxis should start with the removal of exposure to the known or suspected trigger, followed by the assessment of the patient's circulation, airway patency, breathing, and mental status. The administration of epinephrine at a dose of 0.01 mg/kg (1:1000) intramuscularly is the first-line treatment for anaphylaxis, and there are no absolute contraindications to this treatment. The maximum single dose of epinephrine is 0.5 mg and may be repeated after 5-10 minutes if needed. After administration of epinephrine, patients with anaphylaxis should be placed supine with their lower limbs elevated. They should not be placed in the upright position. Studies of fatal and near-fatal allergic reactions identified potential risk factors for fatalities such as asthma, peanuts and/or tree nuts, and delayed epinephrine use, and provided important information that may help minimize the future risk. Patients and their families need to be well educated on how to manage potential anaphylactic reactions with training in the use of epinephrine autoinjectors and personalized emergency management plans. Health care professionals must be familiar with this clinical emergency and able to respond to anaphylaxis in a timely and appropriate manner.

Food allergy epidemiology and racial and/or ethnic differences

In recent decades, immunoglobulin E (IgE) mediated food allergy has become a growing public health concern. Converging evidence from cross-sectional prevalence studies, health care utilization records, and cohort studies indicate that food allergies are increasingly prevalent and often severe. Although IgE-mediated food allergy has long been considered a predominantly pediatric concern, analysis of recent self-reported data suggests that food allergies may be more prevalent among adult populations than previously acknowledged, with many reported cases of adult-onset allergies as well as persistent childhood-onset allergies. Results of studies also suggest that food allergy-related health care utilization is increasing as more individuals seek emergency treatment for food-induced anaphylaxis. Analysis of epidemiologic data also indicates that the burden of food allergies is unequally distributed. Published prevalence rates are highest in Western countries, e.g., the United States, United Kingdom, and Australia. Within these countries, there also is heterogeneity across racial and/or ethnic groups, with non-White and second-generation immigrant populations disproportionately affected. Importantly, such observations can shed light on the etiology of food allergy and inform improved clinical management, treatment, and prevention efforts. For example, there is a growing consensus that earlier introduction of allergenic foods, e.g., peanut, promotes oral tolerance and can dramatically reduce food allergy risk. In addition, much attention has been paid to the potentially deleterious effects of cutaneous allergen exposure, e.g., through eczematous skin, which can skew the immune response away from tolerance and toward allergic sensitization, thereby increasing food allergy risk. Furthermore, there is a growing appreciation for the potential protective effects of diverse microbial exposures, given mounting evidence for the immunomodulatory effects of the human microbiome. Also, when considering the geographic variability in the prevalence of certain food and environmental allergies as well as their structural similarities at the molecular level, it is believed that co-sensitization between food and environmental allergens may be a key driver of rising food allergy prevalence.

Understanding Food-Related Allergic Reactions Through a US National Patient Registry

BACKGROUND

Although previous studies have focused on unintentional food-related allergic reactions, few have explored the motivation of intentional exposure to a known food allergen, independent of oral food challenges and/or oral immunotherapy. Still, data on the frequency and context of food-related allergic reactions remain sparse.

OBJECTIVE

To identify the frequency and context of food-related allergic reactions among children and adults.

METHODS

We analyzed surveys from the Patient Registry established by Food Allergy Research and Education. Multivariable logistic regression evaluated characteristics associated with having frequent food-related allergic reactions as well as intentional food-related allergic reactions.

RESULTS

Over one-third of 4075 (37.7%) respondents reported having more than 1 food-related allergic reaction per year, and 12.8% reported having 1 reaction per year. Of the 3054 respondents who completed the most recent reaction survey, 9.9% of food allergen exposures were classified as intentional, 82.1% as unintentional, and 4.8% as medically related. Among children with intentional exposures, the most common reason was that the child had never had a serious reaction (50.0%), and among adults, it was the decision to take the risk anyway (47.8%). Cross-contamination was the most commonly cited reason for unintentional exposure (children: 24.1%; adults: 32.2%).

CONCLUSION

Among patients in a national food allergy registry, reports of food-related allergic reactions were common, and a non-negligible number of intentional reactions were reported. Our findings indicate the need for research on reactions in and out of the emergency department as well as intentional risk-taking behavior.

Dietary and Microbial Determinants in Food Allergy

The steep rise in food allergy (FA) has evoked environmental factors involved in disease pathogenesis, including the gut microbiota, diet, and their metabolites. Early introduction of solid foods synchronizes with the "weaning reaction," a time during which the microbiota imprints durable oral tolerance. Recent work has shown that children with FA manifest an early onset dysbiosis with the loss of Clostridiales species, which promotes the differentiation of ROR-γt+ regulatory T cells to suppress FA. This process can be reversed in pre-clinical mouse models by targeted bacteriotherapy. Here, we review the dominant tolerance mechanisms enforced by the microbiota to suppress FA and discuss therapeutic intervention strategies that act to recapitulate the early life window of opportunity in stemming the FA epidemic.

A novel patient-reported outcomes instrument assessing the side effects of peanut oral immunotherapy

BACKGROUND

Patients treated with peanut oral immunotherapy (OIT) may experience adverse reactions, particularly during up-dosing.

OBJECTIVE

To develop the Side Effects of Peanut Oral Immunotherapy Diary (SEPOD), an electronic questionnaire assessing the daily side effects of peanut OIT in clinical trials.

METHODS

Content and design of the SEPOD were informed by empirical literature review and meetings with 3 allergy-immunology experts. Interviews to confirm content and inform revisions were conducted in 24 pediatric patients with peanut allergy (14 treated with peanut OIT) aged 6 to 17 years; children aged 6 to 11 years were interviewed with their caregiver.

RESULTS

The SEPOD was drafted after literature review and expert interviews; the initial measurement approach comprised 2 SEPOD versions, a patient-reported outcome (PRO) version for children aged 12 to 17 years, and a caregiver-administered PRO version for children aged 6 to 11 years with instructions for caregiver questionnaire administration. Pediatric patients were expected to respond independently on both versions. Patient interviews indicated that some younger children (ie, aged 6-8 years) had difficulty understanding questions, even when reading aloud; therefore, a caregiver-administered outcome version, identical in content to the caregiver-administered PRO version, was developed for this age group. The final electronic SEPOD covered 23 peanut OIT side effects within the following 7 domains: gastrointestinal, dermatologic, itching, nasal, and respiratory, swelling (eyelid or periorbital, lip, tongue, and throat), pain (tongue, mouth, and throat), and dizziness.

CONCLUSION

This study yielded the SEPOD, a new clinical outcome assessment instrument with various methods of administration that can be used to assess the side effects of peanut OIT experienced by pediatric patients in a clinical trial setting.

Multi-laboratory validation of the xMAP-Food Allergen Detection Assay: A multiplex, antibody-based assay for the simultaneous detection of food allergens

The increasing prevalence of individuals with multiple food allergies and the need to distinguish between foods containing homologous, cross-reactive proteins have made the use of single-analyte antibody-based methods (e.g., ELISAs) sometimes insufficient. These issues have resulted in the need to conduct multiple analyses and sometimes employ orthogonal methods like mass spectrometry or DNA-based methods for confirmatory purposes. The xMAP Food Allergen Detection Assay (xMAP FADA) was developed to solve this problem while also providing increased throughput and a modular design suitable for adapting to changes in analytical needs. The use of built-in redundancy provides the xMAP FADA with built-in confirmatory analytical capability by including complementary antibody bead sets and secondary analytical end points (e.g., ratio analysis and multi-antibody profiling). A measure of a method's utility is its performance when employed by analysts of varying expertise in multiple laboratory environments. To gauge this aspect, a multi-laboratory validation (MLV) was conducted with 11 participants of different levels of proficiency. The MLV entailed the analysis of incurred food samples in four problematic food matrices, meat sausage, orange juice, baked muffins, and dark chocolate. Except for a couple of instances, involving two confirmatory components in the analysis of baked muffins, the allergenic foods were detected by all participants at concentrations in the analytical samples comparable to ≤ 10 μg/g in the original food sample. In addition, despite high levels of inter-lab variance in the absolute intensities of the responses, the intra-laboratory reproducibility was sufficient to support analyses based on the calibration standards and direct comparison controls (DCCs) analyzed alongside the samples. In contrast, ratio analyses displayed inter-laboratory %CV (RSDR) values < 20%; presumably because the ratios are based on inherent properties of the antigenic elements. The excellent performance of the xMAP FADA when performed by analysts of varying proficiency indicates a reliability sufficient to meet analytical needs.

A counseling video with pre- and posttesting and checklist for oral immunotherapy consent improves participant knowledge

BACKGROUND

The use of oral immunotherapy (OIT) for food allergies has been expanding in North America. Although families are interested in this therapeutic approach, misconceptions are common; therefore, education of these families is essential before obtaining informed consent.

OBJECTIVE

To improve parent and patient knowledge about OIT by investigating the use of a counseling video (CV) and checklist.

METHODS

This retrospective review was conducted in a pediatric outpatient clinic. After consultation and review of the information package, 467 parents and patients (>12 years old) performed pre- and posttests in conjunction with a CV during a checklist-based 2-hour counseling session for OIT.

RESULTS

The evaluation of pre- and posttest performance suggested an improvement in the ability of patients to answer relevant questions pertaining to OIT. This was statistically significant for all groups, including mothers, fathers, and children (P < .001). Mothers performed better than fathers and patients in mean number of correct responses in both pre- and posttest scores and in posttest scores after adjustment for pretest scores. Fathers performed better than patients in both pre- and posttest scores but not on posttest scores after adjustment for pretest scores. A checklist-based format resulted in 100% of all major topics being discussed in a 1-hour discussion. Reported satisfaction was high among the participants.

CONCLUSION

This is the first study to evaluate the use of a CV in conjunction with pre- and posttesting to educate families about the key principles of OIT. We suggest that as part of extensive counseling for OIT, an educational video is beneficial in a pediatric outpatient clinic.

Climate Change and Human Health: A Review of Allergies, Autoimmunity and the Microbiome

The impact of climate change on human health is a topic of critical importance. While only recently beginning to gain attention, it is clear that immediate action is necessary to minimize this impact. In our review, we will outline a subset of these effects in detail. We will examine how climate change has worsened respiratory allergic disease. We will discuss how climate change has altered antigen exposure, possibly disrupting antigen-specific tolerance by the immune system, leading, in turn, to an increase in the prevalence of immunologic diseases. Finally, we will explore how the loss of biodiversity related to climate change may affect the microbiome, potentially leading to dysbiosis, inflammatory, autoimmune and neurologic diseases.

Sublingual immunotherapy for food allergy and its future directions

Food allergy is an important medical problem with increasing prevalence throughout the world. Different approaches of food immunotherapy are being investigated including oral, epicutaneous and sublingual routes. Sublingual immunotherapy (SLIT) for food allergy involves placement of glycerinated allergen under the tongue daily to achieve allergen-specific desensitization. SLIT has been studied in the treatment of hazelnut, peach, apple, milk and peanut allergies with substantial focus on the treatment of peanut allergy. Phase II studies have shown SLIT for treatment of peanut allergy increases the tolerated dose of peanut by a substantial margin with fewer and less severe side effects than other modalities. This review discusses the mechanisms of SLIT, early studies of its use in food allergy and larger randomized controlled trials for treatment of peanut allergy. Future directions using the mechanisms involved in SLIT include oral mucosal immunotherapy for peanut allergy.