Towards an optimized model of food allergy in zebrafish.

BACKGROUND: The prevalence of food allergies is on the rise, posing a significant challenge to public health. Rodents serve as the predominant animal model in food allergy research; yet, the application of rodent models proves to be a laborious and time-consuming endeavor. It is imperative to develop novel in vivo models. METHODS: Ovalbumin (OVA) was administered as the allergen, following the recommended dosage used in other species. During the sensitization phase, a dosage of 0.25 mg per 10 tails per 1 L was administered twice daily, and during the challenge phase, the dosage was increased to 3 times the initial level. The study explored two dimensions of sensitization: the mode of exposure, which can be either continuous or intermittent, and the duration of exposure, which includes 3 days, 5 days, and 7 days. We examined midgut pathological changes, immunoglobulins contents, and mRNA expressions associated to T helper cells (Th) 2 cytokines following exposure. RESULTS: A significant 109.3 % increase in the number of eosinophils was observed in the midgut histopathology following intermittent 5-day OVA exposure, which emerged as the most effective model. OVA exposure increased concentrations of immunoglobulin M (IgM) (105.2 %), IgZ (312.1 %), and IgD (304.3 %) in this model. The mRNA expressions of Th2-related interleukin (IL)-4 and IL-13 were also elevated by 132.8 % and 421.0 %, respectively. CONCLUSION: The intermittent 5-day OVA exposure was suggested to be the best constructed zebrafish food allergy model, which may be a potential tool for research into food allergies.

Sensory sentinels: Neuroimmune detection and food allergy.

Food allergy is classically characterized by an inappropriate type-2 immune response to allergenic food antigens. However, how allergens are detected and how that detection leads to the initiation of allergic immunity is poorly understood. In addition to the gastrointestinal tract, the barrier epithelium of the skin may also act as a site of food allergen sensitization. These barrier epithelia are densely innervated by sensory neurons, which respond to diverse physical environmental stimuli. Recent findings suggest that sensory neurons can directly detect a broad array of immunogens, including allergens, triggering sensory responses and the release of neuropeptides that influence immune cell function. Reciprocally, immune mediators modulate the activation or responsiveness of sensory neurons, forming neuroimmune feedback loops that may impact allergic immune responses. By utilizing cutaneous allergen exposure as a model, this review explores the pivotal role of sensory neurons in allergen detection and their dynamic bidirectional communication with the immune system, which ultimately orchestrates the type-2 immune response. Furthermore, it sheds light on how peripheral signals are integrated within the central nervous system to coordinate hallmark features of allergic reactions. Drawing from this emerging evidence, we propose that atopy arises from a dysregulated neuroimmune circuit.

Key factors that influence quality of life in patients with IgE-mediated food allergy vary by age.

BACKGROUND: While food allergy (FA) can be fatal, the greatest public health impact of FA arguably lies in its detrimental effect on quality of life (FAQOL). Understanding the factors that contribute to FAQOL at different ages is essential to develop personalized interventions that will improve FAQOL. OBJECTIVE: To determine the most influential factors that impact FAQOL across ages in well-phenotyped participants with confirmed FA. METHODS: One hundred and twenty-five individuals aged 2-28 years with IgE-mediated FA completed validated age-specific FAQOL questionnaires. The relationship between demographic/clinical variables and scores were analyzed to identify key predictors of FAQOL. RESULTS: Poor FAQOL was associated with increasing age, strict avoidance practices, reactions to trace exposures, and more severe reactions as assessed by epinephrine use, anaphylaxis, and/or treatment in the emergency department; FAQOL improved with time from the event. FAQOL was worse in subjects avoiding >2 versus ≤2 foods and in those avoiding milk, egg, soy, sesame, or wheat. Number of foods avoided had greatest impact on children ages 2-7 years, while total number of allergic reactions strongly impacted FAQOL in teens and adults; FAQOL of subjects ages 8-12 years appeared less affected by these variables compared to other age groups. A decision tree analysis identified key predictors of overall FAQOL (age, number of food avoidances, and time since epinephrine use) that can be used to guide intervention strategies to improve FAQOL. CONCLUSION: We directly compared FAQOL in extensively phenotyped children, teenagers, and adults with confirmed IgE-mediated FA. Age; timing, number, and severity of reactions; type and number of FA; and food avoidance practices influence FAQOL and should guide intervention strategies.

Health care resource use and costs in patients with food allergies: a United States insurance claims database analysis.

Aims: Food allergies impose a large clinical and financial burden on patients and the health care system. However, little is known about the factors associated with health care resource use and costs. The aim of this study was to investigate health care resource use and costs in individuals with food allergies utilizing health care in the United States.Methods: We conducted a retrospective analysis of insurance claims data from the Merative™ MarketScan® Research Databases (indexed from January 1, 2015, to June 30, 2022). All-cause and food allergy-related health care resource use, direct medical, and out-of-pocket costs for medical services were estimated for 12 months post-index using International Classification of Diseases [ICD] codes.Results: Of 355,520 individuals with food allergies continuously enrolled in a health insurance plan for ≥12 months pre- and post-index, 17% had a food allergy-related emergency department visit and 0.9% were hospitalized. The top patient characteristics associated with all-cause and food allergy-related hospitalizations, all-cause costs, and food allergy-related outpatient visit costs was a Charlson Comorbidity Index score of ≥2. Food allergy-related direct medical and out-of-pocket costs were high among patients with a food allergy-related visit. Out-of-pocket cost per patient per year for outpatient visits, emergency department visits, and hospitalizations had an estimated mean of $1,631 for patients with food allergy-related visits, which is approximately 11% of the total costs for these services ($14,395 per patient per year).Limitations: Study limitations are primarily related to the nature of claims databases, including generalizability and reliance on ICD codes. Nevertheless, MarketScan databases provide robust patient-level insights into health care resource use and costs from a large, commercially insured patient population.Conclusion: The health care resource use of patients with food allergies imposes a burden on both the health care system and on patients and their families, especially if patients had comorbidities.

Conducting a successful diet trial for the diagnosis of food allergy in dogs and cats.

A limited antigen diet trial and subsequent food provocation is currently the optimal method of confirming a diagnosis of food allergy in dogs and cats. However, performing an effective diet trial can be challenging as it requires a high level of client and pet compliance, appropriate diet selection and correct interpretation of the provocative challenge. This narrative guides the clinician through the process, highlights potential pitfalls and specifies how these can be avoided to achieve a successful outcome.

Buckwheat Allergy in Asia.

PURPOSE OF REVIEW: Buckwheat (BW) allergy is a significant issue in Asia. This review delves into three types of BW allergy: immediate food allergy; food-dependent, exercise-induced anaphylaxis (FDEIA) as a subset of immediate food allergy; and food protein-induced enterocolitis syndrome (FPIES); by comparing data from Asian and non-Asian countries. RECENT FINDINGS: Most studies on BW have been published in Japan and Korea, and only a few studies on the topic have been done outside Asia. To date, seven components of common BW (Fagopyrum esculentum) and four components of Tartary BW (Fagopyrum tartaricum) have been implicated in BW allergy. Although BW-sIgE has limited utility for evaluating immediate BW allergy, Fag e 3-specific IgE, one of the components of common BW, and the skin prick test are diagnostically useful. The present review aims to shed light on the current state of knowledge, highlight research gaps, and suggest future directions in the management and understanding of BW allergy.

Food-Pollen Cross-Reactivity and its Molecular Diagnosis in China.

PURPOSE OF REVIEW: Plant-derived foods are one of the most common causative sources of food allergy in China, with a significant relationship to pollinosis. This review aims to provide a comprehensive overview of this food-pollen allergy syndrome and its molecular allergen diagnosis to better understand the cross-reactive basis. RECENT FINDINGS: Food-pollen cross-reactivity has been mainly reported in Northern China, Artemisia pollen is the major related inhalant source, followed by tree pollen (Betula), while grass pollen plays a minor role. Pollen allergy is relatively low in Southern China, with allergies to grass pollen being more important than weed and tree pollens. Rosaceae fruits and legume seeds stand out as major related allergenic foods. Non-specific lipid transfer protein (nsLTP) has been found to be the most clinically relevant cross-reacting allergenic component, able to induce severe reactions. PR-10, profilin, defensin, chitinase, and gibberellin-regulated proteins are other important cross-reactive allergen molecules. Artemisia pollen can induce allergenic cross-reactions with a wide range of plant-derived foods in China, and spring tree pollens (Betula) are also important. nsLTP found in both pollen and plant-derived food is considered the most significant allergen in food pollen cross-reactivity. Component-resolved diagnosis with potential allergenic proteins is recommended to improve diagnostic accuracy and predict the potential risk of causing allergic symptoms.

Clinical and serological characteristics of patients allergic to LTP.

BACKGROUND: Allergy to lipid transfer proteins (LPT) is common in Mediterranean Europe, and it causes severe reactions in patients and affects multiple foods, impairing the quality of life. OBJECTIVE: This study aimed to describe the clinical and sensitization profile of patients with LTP syndrome and to determine a clinical pattern of severity. Molecular diagnosis is shown in a broad population through microarrays. MATERIAL AND METHODS: This study was performed at the LTP Allergy Consultation of the Reina Sofia Hospital in Murcia, Spain. We analyzed the patients' characteristics, reactions, cofactors, food implicated, quality of life, skin prick test to food and aeroallergens, and serologic parameters, such as total immunoglobulin E, peach LTP (Pru p 3 IgE) and immunoglobulin G4, and microarray Immuno Solid-phase Allergen Chip (ISAC). We related the severity of the reactions with other variables. RESULTS: We presented a series of 236 patients diagnosed with LTP allergy, 54.66% suffering from anaphylaxis, 36.02% from urticaria angioedema, and 9.32% from oral allergy syndrome. The most frequently implicated food was peach, producing symptoms in 70% of patients, followed by walnut in 55%, peanut in 45%, hazelnut in 44%, and apple in 38% patients. Regarding the food that provoked anaphylaxis, walnut was the most frequent instigator, along with peach, peanut, hazelnut, almond, sunflower seed, and apple. According to the severity of LPT reaction, we did not discover significant differences in gender, age, food group involved, and serologic parameters. We found differences in the presence of cofactors, with 48.84% of cofactors in patients with anaphylaxis, compared to 27.1% in patients without anaphylaxis and in family allergy background (P < 0.0001). CONCLUSION: In our series of patients, 54% presented anaphylaxis, and the foods that most frequently produced symptoms were peaches, apples, and nuts. Cofactors and family allergy backgrounds were associated with the severity of LPT reaction.

Early-life risk factors which govern pro-allergic immunity.

Allergic diseases affect up to 40% of the global population with a substantial rise in food allergies, in particular, over the past decades. For the majority of individuals with allergy fundamental programming of a pro-allergic immune system largely occurs in early childhood where it is crucially governed by prenatal genetic and environmental factors, including their interactions. These factors include several genetic aberrations, such as filaggrin loss-of-function mutations, early exposure to respiratory syncytial virus, and various chemicals such as plasticizers, as well as the influence of the gut microbiome and numerous lifestyle circumstances. The effects of such a wide range of factors on allergic responses to an array of potential allergens is complex and the severity of these responses in a clinical setting are subsequently not easy to predict at the present time. However, some parameters which condition a pro-allergic immune response, including severe anaphylaxis, are becoming clearer. This review summarises what we currently know, and don't know, about the factors which influence developing pro-allergic immunity particularly during the early-life perinatal period.

Low serum adrenic acid levels in infants and subsequent food-induced anaphylaxis.

Background: The dietary fat hypothesis links increases in allergic diseases to reduced consumption of n-3 polyunsaturated fatty acids from fish, for example, eicosapentaenoic acid, and increased intake of n-6 polyunsaturated fatty acids from vegetable oils, for example, arachidonic acid. Objective: Building upon the "fat hypothesis," we sought to investigate the association between 24 types of serum fatty acid levels in infants and the risk of subsequent food-induced anaphylaxis (FIA) by age 2 years as the primary outcome. Methods: This study was conducted as a prespecified supplemental analysis within the ABC randomized clinical trial. We measured levels of 24 fatty acids in residual serum samples collected from 268 infants at age 5 to 6 months using gas chromatography-mass spectrometry. Results: Among the 258 infants, 58 exhibited immediate-type food allergies, whereas 200 showed no food allergy. Of the 58 infants, 12 were diagnosed with FIA, whereas the remaining 46 had nonanaphylactic food allergy. Unexpectedly, among the 24 fatty acids, only adrenic acid, also known as docosatetraenoic acid, which is one of the n-6 polyunsaturated fatty acids, showed significantly lower levels in infants with FIA (median [interquartile range] (wt.%), 0.16 [0.14-0.17]), compared with those with no food allergy (0.19 [0.17-0.21]) (P = .0007). In contrast, adrenic acid levels in infants with nonanaphylactic food allergy were 0.19 [0.16-0.21] (wt.%), which did not differ significantly from those in infants with no food allergy (P = .69). Conclusions: This study generated a hypothesis suggesting that infants with low serum adrenic acid levels might be at greater risk of subsequent FIA. This unexpected result warrants further investigation.

Preclinical efficacy of peanut-specific IgG4 antibody therapeutic IGNX001.

BACKGROUND: Existing therapeutic strategies are challenged by long times to achieve effect and often require frequent administration. Peanut allergic individuals would benefit from a therapeutic that provides rapid protection against accidental exposure within days of administration while carrying little risk of adverse reactions. OBJECTIVE: Guided by the repertoire of human IgE monoclonal antibodies (mAbs) from allergic individuals, we sought to develop a treatment approach leveraging the known protective effects of allergen-specific IgG4 antibodies. METHODS: We applied our single-cell RNA sequencing SEQ SIFTER™ platform to whole blood samples from peanut allergic individuals to discover IgE mAbs. These were then class-switched by replacing the IgE constant region with IgG4 while retaining the allergen-specific variable regions. In vitro mast cell activation tests (MATs), basophil activation tests (BATs), enzyme-linked immunosorbent assays (ELISAs), and an in vivo peanut allergy mouse model were used to evaluate the specificity, affinity, and activity of these recombinant IgG4 mAbs. RESULTS: We determined that human peanut-specific IgE mAbs predominantly target immunodominant epitopes on Ara h 2 and Ara h 6 and that recombinant IgG4 mAbs effectively blocked these epitopes. IGNX001, a mixture of two such high-affinity IgG4 mAbs, provided robust protection against peanut-mediated mast cell activation in vitro as well as against anaphylaxis upon intragastric peanut challenge in a peanut allergy mouse model. CONCLUSION: We developed a peanut-specific IgG4 antibody therapeutic with convincing preclinical efficacy starting from a large repertoire of human monoclonal IgE antibodies from demographically and geographically diverse individuals. These results warrant further clinical investigation of IGNX001 and underscore the opportunity for the application of this therapeutic development strategy in other food and environmental allergies.

Elimination Diets in Lactating Mothers of Infants with Food Allergy.

Breastfeeding is the most important nutrition source for infants. However, managing breastfed infants with signs and symptoms related to food allergy can be difficult. Many studies have shown the presence of different food allergens in breast milk, but the clinical role of these antigens in human milk is still much debated. Milk is the main suspect in exclusively breastfed infants with signs and symptoms attributable to food allergy, even if other foods may be responsible. This narrative review analyzes the recommendations provided by international guidelines to determine the diagnosis and management of IgE-mediated and non-IgE-mediated food allergies in exclusively breastfed infants. Dietary restrictions in lactating mothers of infants with suspected FA are usually not necessary. Only in the very few cases where significant allergy signs and symptoms occur in the infant during exclusive breastfeeding should the lactating mother follow an elimination diet for the suspected food for a short period.

Viral Vector Based Immunotherapy for Peanut Allergy.

Food allergy (FA) is estimated to impact up to 10% of the population and is a growing health concern. FA results from a failure in the mucosal immune system to establish or maintain immunological tolerance to innocuous dietary antigens, IgE production, and the release of histamine and other mediators upon exposure to a food allergen. Of the different FAs, peanut allergy has the highest incidence of severe allergic responses, including systemic anaphylaxis. Despite the recent FDA approval of peanut oral immunotherapy and other investigational immunotherapies, a loss of protection following cessation of therapy can occur, suggesting that these therapies do not address the underlying immune response driving FA. Our lab has shown that liver-directed gene therapy with an adeno-associated virus (AAV) vector induces transgene product-specific regulatory T cells (Tregs), eradicates pre-existing pathogenic antibodies, and protects against anaphylaxis in several models, including ovalbumin induced FA. In an epicutaneous peanut allergy mouse model, the hepatic AAV co-expression of four peanut antigens Ara h1, Ara h2, Ara h3, and Ara h6 together or the single expression of Ara h3 prevented the development of a peanut allergy. Since FA patients show a reduction in Treg numbers and/or function, we believe our approach may address this unmet need.

Inhibition of DNMT1 attenuates experimental food allergy.

BACKGROUND: The treatment of food allergy (FA) needs improvement. The treatment of immune disorders can be improved by regulating epigenetic marks, which is a promising method. The objective of this research is to alleviate experimental FA by employing an inhibitor of DNA methyltransferase-1 (DNMT1). METHODS: Ovalbumin was used as the specific antigen to establish a mouse model of FA. Intestinal IL-35+ regulatory B cells (Breg cells) were isolated from FA mice, and characterized using immunological approaches. RESULTS: FA mice had a lower frequency of IL-35+ Breg cells, which was inversely correlated with their FA response. The quantity of IL-35 was lower in intestinal Breg cells from FA mice. Hypermethylation status was detected in the Il35 promoter, which was accompanied with high levels of H3K9me3. Enforced expression of DNMT1 hindered the promoter activity of the IL35 gene. Administration of an inhibitor of DNMT1 (RG108) restored the immune regulatory capacity of FA intestinal Bregs, and effectively suppressed the expression of DNMT1, and attenuated experimental FA. CONCLUSIONS: The elevated quantity of DNMT1 in intestinal Breg cells compromises the expression of IL-35 and affects the immune regulatory functions, which facilitates the development of FA. The immune regulatory functions of intestinal Breg cells are restored and experimental FA is attenuated by inhibiting DNMT1.

Zinc Deficiency and Zinc Supplementation in Allergic Diseases.

In recent decades, it has become clear that allergic diseases are on the rise in both Western and developing countries. The exact reason for the increase in prevalence has not been conclusively clarified yet. Multidimensional approaches are suspected in which diet and nutrition seem to play a particularly important role. Allergic diseases are characterized by a hyper-reactive immune system to usually harmless allergens, leading to chronic inflammatory diseases comprising respiratory diseases like asthma and allergic rhinitis (AR), allergic skin diseases like atopic dermatitis (AD), and food allergies. There is evidence that diet can have a positive or negative influence on both the development and severity of allergic diseases. In particular, the intake of the essential trace element zinc plays a very important role in modulating the immune response, which was first demonstrated around 60 years ago. The most prevalent type I allergies are mainly based on altered immunoglobulin (Ig)E and T helper (Th)2 cytokine production, leading to type 2 inflammation. This immune status can also be observed during zinc deficiency and can be positively influenced by zinc supplementation. The underlying immunological mechanisms are very complex and multidimensional. Since zinc supplements vary in dose and bioavailability, and clinical trials often differ in design and structure, different results can be observed. Therefore, different results are not surprising. However, the current literature suggests a link between zinc deficiency and the development of allergies, and shows positive effects of zinc supplementation on modulating the immune system and reducing allergic symptoms, which are discussed in more detail in this review.

Exploring young adults' experiences with food allergy during their teenage years: A practice research study.

INTRODUCTION: Symptoms of anxiety, eating disorders and social isolation are prevalent among teenagers with food allergy compared to peers without. Treatment of teenagers with food allergy focus on preventing anaphylactic reactions, with little attention to promoting social and emotional well-being. The aim of the study was to explore young adults' perspectives on everyday life with food allergy during their teenage years to improve future clinical practice. METHODS: Critical psychological practice research. During a 2-day camp the perspectives of 10 young adults (18-23 years) were explored through participant observation and informal interviews. Three follow up interviews were conducted. A co-researcher group discussed preliminary results, clinical challenges and ways forward. RESULTS: Being together with peers with food allergy was crucial, fostering belonging and normalisation. The shift in responsibility of managing the risk feels overwhelming and stressful during teen age. Self-understanding was influenced when managing food allergy in social contexts, inducing feelings of burden and isolation. Acceptance and understanding from social relations became important for all participants, and they all underlined desire for being viewed as individuals rather than being defined by their allergy. CONCLUSION: Support from other peers with food allergy is crucial for the participants. Transition to independently managing risks introduces uncertainty and social constraints, affecting self-understanding and interactions. Clinicians should prioritise peer support and empower teenagers in managing the risk and psychosocial challenges.

The Diagnosis of Allergy to Lipid Transfer Proteins.

PURPOSE OF REVIEW: To provide an update on the diagnosis of non-specific Lipid Transfer Protein (nsLTP) allergy. RECENT FINDINGS: More publications report the presence of nsLTP allergy in Northern European countries and nsLTP sensitisation in children. Individuals are more likely to have severe reactions if there is recognition of increasing numbers of LTP components. Diagnosis is problematic; not all those with nsLTP allergy will have a positive test to a peach extract containing Pru p 3, the peach nsLTP. Sensitisation to nsLTP is being reported in more countries, including to the nsLTP in Cannabis Sativa in North America. Meals containing multiple nsLTP foods are more likely to be involved in co-factor reactions. Component-resolved diagnostics are superior to skin prick tests, to determine sensitisation to the individual nsLTP allergens causing symptoms and, in the future, the Basophil Activation test may best discriminate between sensitization and clinical allergy.

Global availability and uptake of psychological services for adults, caregivers and children with food allergy.

BACKGROUND: Food allergy (FA) is associated with poor health-related quality of life and high levels of psychological distress. Psychological support is extremely important but not always available. As part of the Global Access to Psychological Services for Food Allergy (GAPS) study, we aimed to assess psychological distress and service use among adults, caregivers and children with FA in a global survey. METHODS: Participants (n = 1329 adults with FA; n = 1907 caregivers of children with FA) from >20 countries were recruited through patient organisations, social media advertisements and online survey panels to complete an online survey. Surveys were available in six languages. RESULTS: A total of 67.7% of adults and 77.2% of caregivers reported direct experience, and 51.6% of caregivers said their child had experienced FA-related psychological distress. The most commonly reported issue was anxiety about having an allergic reaction. Less than 20% had been assessed for FA-related psychological distress. There were significant differences across countries for levels of distress, screening for distress, seeing a mental health professional and being diagnosed with a FA-related mental health disorder (all p < .001). The United Kingdom, Australia and Brazil had the highest number of participants reporting distress. The most commonly reported barrier to seeing a mental health professional was cost. CONCLUSIONS: FA-related distress is common across countries, but with substantial country-to-country variability. Allergy providers are encouraged to routinely assess families for psychological distress and provide access to appropriate mental health resources. Development and implementation of evidence-based, patient-informed accessible, affordable FA interventions in multiple languages is urgently needed.