Food allergy immunotherapy: Oral immunotherapy and epicutaneous immunotherapy

Current perspective on allergen immunotherapy for food allergies

Food allergies are an increasing global problem and societal issue. In addition to the potential for severe allergic reactions from accidental ingestion, food allergies impose a significant burden on the quality of life, nutrition, cost of living, and social activities of both those afflicted and their caregivers. Strict avoidance of allergens and use of emergency medications to treat allergic reactions are the traditional management and treatment strategies; however, significant progress has been made in recent years toward better treatment of food allergies. Many clinical trials on food allergen immunotherapy (oral, epicutaneous, and sublingual) have revealed its efficacy in increasing reaction thresholds and desensitization. These positive results led to the first FDA approval of peanut oral immunotherapy (OIT). However, safer and more effective approaches are required, and adjunct treatments and allergen modifications are being considered. More than 100 facilities in Japan conduct OIT, and numerous studies on it have been reported. Unlike in Europe and the US, stepwise oral food challenges with dietary guidance are conducted separately from the OIT. This review describes the current perspectives on allergen immunotherapy for the treatment of food allergies, focusing on evidence from Japan.

Recent advances in food allergen immunotherapy

Food allergies can pose significant risks and profoundly impact the quality of life of children and their families, making them a major public health concern. Allergen avoidance has been the traditional mainstay of treatment; however, recent research has focused on various approaches to food allergen immunotherapy. This review summarizes the recent advancements in oral, sublingual, and epicutaneous immunotherapies, highlighting their respective advantages and disadvantages. The ultimate goal of food allergen immunotherapy is to maximize efficacy while minimizing risks, leading to the exploration of strategies such as low-dose immunotherapy and the use of biologics. When selecting candidates for immunotherapy among patients with food allergies, factors such as allergen characteristics, the likelihood of natural resolution, age, symptom severity, and impact on quality of life require consideration, and an individualized approach should be adopted to determine the most suitable treatment method.

Bruton's tyrosine kinase inhibition for the treatment of allergic disorders

IgE signaling through its high-affinity receptor FcεRI is central to the pathogenesis of numerous allergic disorders. Oral inhibitors of Bruton's tyrosine kinase (BTKis), which are currently Food and Drug Administration-approved for treating B cell malignancies, broadly inhibit the FcεRI pathway in human mast cells and basophils, and therefore may be effective allergen-independent therapies for a variety of allergic diseases. The application of these drugs to the allergy space was previously limited by the low kinase selectivity and subsequent toxicities of early-generation compounds. Fortunately, next-generation, highly selective BTKis in clinical development appear to have more favorable risk-benefit profiles, and their likelihood of being Food and Drug Administration-approved for an allergy indication is increasing. Recent clinical trials have indicated the remarkable and rapid efficacy of the second-generation BTKi acalabrutinib in preventing clinical reactivity to peanut ingestion in adults with peanut allergy. In addition, next-generation BTKis including remibrutinib effectively reduce disease activity in patients with antihistamine-refractory chronic spontaneous urticaria. Finally, several BTKis are currently under investigation in early clinical trials for atopic dermatitis and asthma. In this review, we summarize recent data supporting the use of these drugs as novel therapies in food allergy, anaphylaxis, urticaria, and other allergic disorders. We also discuss safety data derived from trials using both short-term and chronic dosing of BTKis.

Safety and efficacy of epicutaneous immunotherapy with DBV712 (peanut patch) in peanut allergy

INTRODUCTION

DBV712 250 µg (also referred to as Viaskin Peanut or peanut patch; Viaskin is a trademark of DBV Technologies) is an innovative approach to epicutaneous immunotherapy (EPIT). The patch-based technology system facilitates peanut protein (allergen) absorption into the intact non-vascularized epidermis to promote desensitization to peanut while limiting systemic allergen exposure.

AREAS COVERED

Efficacy and safety in children have been evaluated in four completed phase 3 studies. Overall, the results from these studies have demonstrated the peanut patch to be superior in desensitization compared with placebo and safe for daily use over multiple years.

EXPERT OPINION

These findings, as well as supportive evidence from phase 2 studies, confirm the potential for an effective treatment of peanut allergy in children. The purpose of this review is to summarize the safety and efficacy of the peanut patch in the treatment of peanut allergy.

Management of food allergy based on oral food challenge

PURPOSE OF REVIEW

Food allergy is a growing health problem that affects both patients and society in multiple ways. Despite the emergence of novel diagnostic tools, such as component-resolved diagnostics (CRD) and basophil activation tests (BAT), oral food challenge (OFC) still plays an indispensable role in the management of food allergies. This review aimed to highlight the indications and safety concerns of conducting an OFC and to provide insights into post-OFC management based on recent findings.

RECENT FINDINGS

Standardized OFC protocols have regional diversification, especially in Japan and Western countries. Recent studies suggested that the interval between doses should be at least more than an hour. Furthermore, applying a stepwise method tailored to the patient's specific immunoglobulin E level and history of anaphylaxis seems to mitigate these risks. Recent surveys have shown that, following a positive OFC, options other than strict avoidance are also selected.

SUMMARY

OFC serves diverse purposes, yet the risks it carries warrant caution. The stepwise protocol appears promising for its safety. Subthreshold consumption following OFC shows potential; however, further research on its efficacy and safety is required. Management following OFC should be tailored and well discussed between clinicians and patients.

Engineering nanoparticle therapeutics for food allergy

Food allergy is a growing public health issue among children and adults that can lead to life-threatening anaphylaxis following allergen exposure. The criterion standard for disease management includes food avoidance and emergency epinephrine administration because current allergen-specific immunotherapy treatments are limited by adverse events and unsustained desensitization. A promising approach to remedy these shortcomings is the use of nanoparticle-based therapies that disrupt disease-driving immune mechanisms and induce more sustained tolerogenic immune pathways. The pathophysiology of food allergy includes multifaceted interactions between effector immune cells, including lymphocytes, antigen-presenting cells, mast cells, and basophils, mainly characterized by a TH2 cell response. Regulatory T cells, TH1 cell responses, and suppression of other major allergic effector cells have been found to be major drivers of beneficial outcomes in these nanoparticle therapies. Engineered nanoparticle formulations that have shown efficacy at reducing allergic responses and revealed new mechanisms of tolerance include polymeric-, lipid-, and emulsion-based nanotherapeutics. This review highlights the recent engineering design of these nanoparticles, the mechanisms induced by them, and their future potential therapeutic targets.

Practical issues of oral immunotherapy for egg or milk allergy

Oral immunotherapy (OIT) has been recommended to reduce parental burden related to strict allergen avoidance and induce desensitization and immune tolerance for patients with long-lasting allergies to hen's eggs (HE) or cow's milk (CM). OIT should be monitored by pediatric allergists specializing in OIT and oral food challenge tests to manage allergic reactions. Although a previous history of anaphylaxis or multiple food allergies is not a contraindication to OIT, it is contraindicated if the patient has uncontrolled asthma, a malignancy, active systemic autoimmune disorders, or diseases requiring treatment with beta-blockers. A variety of OIT protocols have been de veloped to ensure better outcomes and safe up-dosing, including adjunctive therapies with biologics. This review provides insight into the practical issues of various immunotherapy options for children with HE or CM allergies.

Transcriptomic changes associated with oral immunotherapy for food allergy

This review summarizes recent advances in characterizing the transcriptional pathways associated with outcomes following Oral Immunotherapy. Recent technological advances including single-cell sequencing are transforming the ways in which the transcriptional landscape is understood. The application of these technologies is still in its infancy in food allergy but here we summarize current understanding of gene expression changes following oral immunotherapy for food allergy and specific signatures underpinning the different clinical outcomes of desensitization and remission (sustained unresponsiveness). T helper 2A cells have been identified as a cell type which correlates with disease activity and is modified by treatment. Molecular features at study entry may differentiate individuals who achieve more positive outcomes during OIT. Recent findings point to T cell anergy and Type 1 interferon pathways as potential mechanisms supporting redirection of the allergen-specific immune response away from allergy towards remission. Despite these developments in our understanding of immune mechanisms following OIT, there are still significant gaps. Additional studies examining immune signatures associated with long term and well-defined clinical outcomes are required to gain a more complete understanding of the pathways leading to remission of allergy, in order to optimize treatments and gain improved outcomes for patients.

Current and Future Treatment of Food Allergies

Food allergy prevalence is rapidly growing among school-age children in the United States, posing a significant health concern in school settings. This article aims to provide an overview of the current state of food allergy treatment options, emergency food allergy care plans, and using epinephrine autoinjectors. In addition, it explores potential future treatment options, including immunotherapy and novel therapeutic approaches. This article emphasizes the crucial role of school nurses in recognizing the treatment options currently available to students and their families, as well as fostering a safe environment for students with food allergies.

A novel peanut allergy immunotherapy: Plant-based enveloped Ara h 2 Bioparticles activate dendritic cells and polarize T cell responses to Th1

Introduction

As the only market-authorized allergen immunotherapy (AIT) for peanut allergy is accompanied by a high risk of side effects and mainly induces robust desensitization without sustained efficacy, novel treatment options are required. Peanut-specific plant-derived eBioparticles (eBPs) surface expressing Ara h 2 at high density have been shown to be very hypoallergenic. Here, we assessed the dendritic cell (DC)-activating and T cell polarization capacity of these peanut-specific eBPs.

Methods

Route and kinetics of eBP uptake were studied by (imaging) flow cytometry using monocyte-derived DCs incubated with fluorescently-labelled Ara h 2 eBPs or natural Ara h 2 (nAra h 2) in the presence or absence of inhibitors that block pathways involved in macropinocytosis, phagocytosis, and/or receptor-mediated uptake. DC activation was monitored by flow cytometry (maturation marker expression) and ELISA (cytokine production). T cell polarization was assessed by co-culturing DCs exposed to Ara h 2 eBPs or nAra h 2 with naïve CD4+ T cells, followed by flow cytometry assessment of intracellular IFNγ+ (Th1) and IL-13+ (Th2), and CD25+CD127-Foxp3+ regulatory T cells (Tregs). The suppressive activity of Tregs was tested using a suppressor assay.

Results

Ara h 2 eBPs were taken up by DCs through actin-dependent pathways. They activated DCs demonstrated by an induced expression of CD83 and CD86, and production of TNFα, IL-6, and IL-10. eBP-treated DCs polarized naïve CD4+ T cells towards Th1 cells, while reducing Th2 cell development. Furthermore, eBP-treated DCs induced reduced the frequency of Foxp3+ Tregs but did not significantly affect T cell IL-10 production or T cells with suppressive capacity. In contrast, DC activation and Th1 cell polarization were not observed for nAra h 2.

Conclusion

Ara h 2 eBPs activate DCs that subsequently promote Th1 cell polarization and reduce Th2 cell polarization. These characteristics mark Ara h 2 eBPs as a promising novel candidate for peanut AIT.

Recent advances in epicutaneous immunotherapy and potential applications in food allergy

Given the potent immunological properties of the skin, epicutaneous immunotherapy (EPIT) emerges as a promising treatment approach for inducing immune tolerance, particularly for food allergies. Targeting the highly immunocompetent, non-vascularized epidermis allows for the application of microgram amounts of allergen while significantly reducing the risk of allergen passage into the bloodstream, thus limiting systemic allergen exposure and distribution. This makes EPIT highly suitable for the treatment of potentially life-threatening allergies such as food allergies. Multiple approaches to EPIT are currently under investigation for the treatment of food allergy, and these include the use of allergen-coated microneedles, application of allergen on the skin pretreated by tape stripping, abrasion or laser-mediated microperforation, or the application of allergen on the intact skin using an occlusive epicutaneous system. To date, the most clinically advanced approach to EPIT is the Viaskin technology platform. Viaskin is an occlusive epicutaneous system (patch) containing dried native allergen extracts, without adjuvants, which relies on frequent application for the progressive passage of small amounts of allergen to the epidermis through occlusion of the intact skin. Numerous preclinical studies of Viaskin have demonstrated that this particular approach to EPIT can induce potent and long-lasting T-regulatory cells with broad homing capabilities, which can exert their suppressive effects in multiple organs and ameliorate immune responses from different routes of allergen exposure. Clinical trials of the Viaskin patch have studied the efficacy and safety for the treatment of life-threatening allergies in younger patients, at an age when allergic diseases start to occur. Moreover, this treatment approach is designed to provide a non-invasive therapy with no restrictions on daily activities. Taken together, the preclinical and clinical data on the use of EPIT support the continued investigation of this therapeutic approach to provide improved treatment options for patients with allergic disorders in the near future.

Preclinical evaluation of alternatives to oral immunotherapy for food allergies

The increasing food allergy incidence has led to significant interest in developing therapies for allergic diseases. Oral allergen-specific immunotherapy (OIT) is a recently FDA-approved therapeutic to treat peanut allergies. OIT utilizes daily allergen dosing to reduce allergic reactions to peanuts. However, there is diminished enthusiasm for daily OIT, potentially due to the strict regimen required to induce desensitization and the risks of severe adverse events. Thus, there remains a need for safe and effective food allergy treatments that are well-received by allergic individuals. Preclinical research studies investigate methods to induce allergen desensitization in animals and support clinical studies that address the limitations of current food allergy OIT. Because allergic reactions are triggered by allergen doses above an individual's activation threshold, immunotherapy regimens that induce allergen desensitization with lower allergen doses or without the requirement of daily administrations may expand the use of food allergy immunotherapy. Administering allergen immunotherapy by alternative routes is a strategy to induce desensitization using lower allergen doses than OIT. Several animal models have evaluated oral, sublingual, epicutaneous, and intranasal immunotherapy routes to treat food allergies. Each immunotherapy route may require different allergen doses, formulations, and treatment schedules to induce desensitization. This article will discuss scientific findings from food allergy immunotherapy animal studies that utilize various immunotherapy routes to induce allergen desensitization to support future clinical studies that enhance the safety and efficacy of allergen immunotherapy to treat food allergies.

An update on recent developments and highlights in food allergy

While both the incidence and general awareness of food allergies is increasing, the variety and clinical availability of therapeutics remain limited. Therefore, investigations into the potential factors contributing to the development of food allergy (FA) and the mechanisms of natural tolerance or induced desensitization are required. In addition, a detailed understanding of the pathophysiology of food allergies is needed to generate compelling, enduring, and safe treatment options. New findings regarding the contribution of barrier function, the effect of emollient interventions, mechanisms of allergen recognition, and the contributions of specific immune cell subsets through rodent models and human clinical studies provide novel insights. With the first approved treatment for peanut allergy, the clinical management of FA is evolving toward less intensive, alternative approaches involving fixed doses, lower maintenance dose targets, coadministration of biologicals, adjuvants, and tolerance-inducing formulations. The ultimate goal is to improve immunotherapy and develop precision-based medicine via risk phenotyping allowing optimal treatment for each food-allergic patient.

Allergenicity of wheat protein in diet: Mechanisms, modifications and challenges

Wheat is widely available in people's daily diets. However, some people are currently experiencing IgE-mediated allergic reactions to wheat-based foods, which seriously impact their quality of life. Thus, it is imperative to provide comprehensive knowledge and effective methods to reduce the risk of wheat allergy (WA) in food. In the present review, recent advances in WA symptoms, the major allergens, detection methods, opportunities and challenges in establishing animal models of WA are summarized and discussed. Furthermore, an updated overview of the different modification methods that are currently being applied to wheat-based foods is provided. This study concludes that future approaches to food allergen detection will focus on combining multiple tools to rapidly and accurately quantify individual allergens in complex food matrices. Besides, biological modification has many advantages over physical or chemical modification methods in the development of hypoallergenic wheat products, such as enzymatic hydrolysis and fermentation. It is worth noting that using biotechnology to edit wheat allergen genes to produce allergen-free food may be a promising method in the future which could improve the safety of wheat foods and the health of allergy sufferers.

Relationship between Food Allergy and Endotoxin Concentration and the Toleration Status at 2 Years: The Japan Environment and Children's Study

Changes in household endotoxin concentration may affect the prognosis of food allergy (FA), but data on the association between household endotoxin concentration and an already-developed FA are scarce. Thus, we investigated the association between environmental endotoxin exposure and tolerance to hen's egg (HE) and cow's milk (CM) using data from children participating in the Japan Environment and Children's Study who had HE allergies (n = 204) and CM allergy (n = 72) in their first year of life. We grouped the endotoxin results into quartiles 1-4 (Q1-Q4). In children with HE allergy and with CM allergy, there was no significant difference in the prevalence of tolerance to HE and CM at 2 years old when comparing endotoxin levels of the children in Q1 with those in Q2, Q3, and Q4, respectively. However, subgroup analyses by the presence of eczema and causal foods revealed that children in Q1 had a lower prevalence of tolerance to foods in some subgroup analyses and lower causal allergen-specific immunoglobulin G4 levels. Although an individually based approach against endotoxin according to background characteristics, such as eczema and causal foods, is necessary, preventing excessive endotoxin removal might contribute to FA resolution in some children.

Varying Approaches to Management of IgE-Mediated Food Allergy in Children Around the World

Food allergy is a chronic disease that affects individuals of all ages and is a significant public health problem globally. This narrative overview examines clinical management strategies for IgE-mediated food allergy in children around the world to understand variations in practice. Information was drawn from clinical practice guidelines, recent research, the websites of professional and governmental bodies with expertise in food allergy, and clinical experts from a broad cross-section of geographical regions. The structure and delivery of clinical services, allergen avoidance and food labeling, and resources to support the management of allergic reactions in the community are discussed in detail. The adoption of emerging food immunotherapies is also explored. Wide variations in clinical management of food allergy were apparent across the different countries. Common themes were continuing issues with access to specialist care and recognition of the need to balance risk reduction with dietary and social restrictions to avoid unnecessary detrimental impacts on the quality of life of food allergy sufferers. Findings highlight the need for standardized presentation of practice and priorities, and may assist clinicians and researchers when engaging with government and funding agencies to address gaps.

Deciphering Differential Behavior of Immune Responses as the Foundation for Precision Dosing in Allergen Immunotherapy

Like in many fields of medicine, the concept of precision dosing has re-emerged in routine practice in allergology. Only one retrospective study on French physicians' practice has addressed this topic so far and generated preliminary data supporting dose adaptation, mainly based on experience, patient profile understanding and response to treatment. Both intrinsic and extrinsic factors shape the individual immune system response to allergen immunotherapy (AIT). Herein, we focus on key immune cells (i.e., dendritic cells, innate lymphoid cells, B and T cells, basophils and mast cells) involved in allergic disease and its resolution to further understand the effect of AIT on the phenotype, frequency or polarization of these cells. We strive to discriminate differences in immune responses between responders and non-responders to AIT, and discuss the eligibility of a non/low-responder subset for dose adaptation. A differential behavior in immune cells is clearly observed in responders, highlighting the importance of conducting clinical trials with large cohorts of well-characterized subjects to decipher the immune mechanism of AIT. We conclude that there is a need for designing new clinical and mechanistic studies to support the scientific rationale of dose adaptation in the interest of patients who do not properly respond to AIT.

Transitioning from epicutaneous to oral peanut immunotherapy

Introduction

Epicutaneous immunotherapy (EPIT) has been tested in clinical trials for children with peanut allergy (PA) for its safety and efficacy in inducing desensitization. Aside from peanut avoidance and symptom management, oral immunotherapy (OIT) is another option for PA patients. However, OIT can be associated with adverse events and pose safety concerns to children and their caregivers.

Methods

This study assessed 27 children who successfully completed a peanut EPIT trial. 18 of them transitioned to peanut OIT with starting doses ranging from 10-600 mg of peanut protein. Our aim was to learn more about the EPIT to OIT experience through descriptive survey responses and to gather information that may support the sequential use of the two immunotherapies for safe and positive outcomes that may not be achieved by either alone.

Results

Overall, children and their caregivers had less anxiety about starting OIT after having had peanut exposure through EPIT. Most children who transitioned from EPIT to OIT had no or minor symptoms initially, with symptoms lessening later in OIT. Most were also able to maintain or increase their peanut dose over time, achieving maintenance doses of 60-2,000 mg.

Discussion

In comparison with current literature on OIT for PA in children, the reported symptoms appeared less severe and less prevalent in the EPIT to OIT group. However, there were 3 participants who withdrew from OIT due to the development of intolerable symptoms. This study provides initial data in support of EPIT to OIT, and larger randomized controlled trials assessing effectiveness of the two therapies together are warranted.

Oral immunotherapy for food allergy: Translation from studies to clinical practice?

Oral immunotherapy (OIT) is now recognized as an alternative active treatment to strict food avoidance in certain patients with IgE-mediated food allergy. Studies have confirmed the efficacy of OIT to desensitize children with allergy to cow's milk, eggs, and peanuts. The benefits, risks, and constraints of OIT are becoming increasingly well understood. However, there is no consensual criteria to select patients to whom OIT could be proposed, and many issues remain to address including the definitions of desensitization and long-term efficacy, the assessment of patient's experience in real life, the optimization of buildup and maintenance protocols, and the utility of multiple food OIT. The recent authorization by medical agency concerning the first medicine for peanut OIT is a step forward towards higher standardization in the practice of OIT. This article summarizes in comprehensive narrative format data on efficacy, tolerance, impact on quality of life and adverse effects of OIT and discuss elements to consider in clinical practice before starting OIT.

Celiac Disease Frequency Is Increased in IgE-Mediated Food Allergy and Could Affect Allergy Severity and Resolution

OBJECTIVES

An increased frequency of celiac disease (CeD) has been reported in severe Immunoglobulin E (IgE) -mediated food allergy (FA). This observation requires confirmation, and whether CeD affects FA severity and resolution is unknown. The study aims to estimate the prevalence of CeD in patients with FA and to investigate whether CeD affects FA severity and oral tolerance.

METHODS

Consecutive patients with FA referred for allergen reintroduction, either to evaluate allergy resolution or to start oral immunotherapy (OIT), were evaluated for CeD and for FA severity. The primary outcome was the prevalence of CeD. Secondary outcomes were the frequency of severe FA and the level of clinical tolerance at study entry and at last follow-up in patients with isolated FA versus patients with FA + CeD.

RESULTS

Two hundred twenty-eight patients were included. CeD was confirmed in 15 patients (6.6%) of whom, 8 patients had a previously established diagnosis of CeD and were on a gluten-free diet. Severe FA was observed in 12 patients with FA + CeD (80%) versus 88 patients with FA (42%) ( P = 0.006). At baseline, patients with FA + CeD had significantly higher median allergen-specific IgE levels [61.8 kU/L; interquartile range (IQR) 11.6-279.0] compared to patients with FA (20.3 kU/L; IQR 2.9-72.7) ( P < 0.001). Complete clinical tolerance was observed in 1 of 15 patients (7%) with FA + CeD versus 98 of 205 patients (48%) with FA ( P = 0.002).

CONCLUSIONS

CeD is highly prevalent in patients with FA and could affect FA severity and response to OIT. CeD screening should be considered in patients with severe or persistent FA.

The potential role of preventive and therapeutic immunonutrition strategies for pediatric food allergy: A mini-review

Food allergy (FA) represents one of the main chronic conditions of the pediatric population. The gut microbiome (GM)-immune system axis is a milestone in affecting FA susceptibility. The dynamic and bidirectional crosstalk between the GM and immune system starts early in life, and it is deeply modulated during the first 1,000 days of life. Nutritional factors during this crucial period mainly influence the proper GM-immune system development and function across the lifespan, with potential beneficial or detrimental effects on health status. Immunonutrition strategies, applied from conception, could represent an innovative target for prevention and treatment of pediatric FA. Here we described the potential role of preventive and therapeutic immunonutrition strategies for pediatric FA, highlighting putative future perspectives in this field.

An overview of the current state of food desensitization

PURPOSE OF REVIEW

To highlight the current evidence on food desensitization in children with food allergy.

RECENT FINDINGS

Food Allergen Specific Immunotherapy (FA-AIT) is currently recognised as a treatment option for treating children with allergy at least to the main common foods (i.e. milk, egg and peanut). The oral route of administration has been proven to be the most effective in achieving desensitisation. Efforts are devoted to overcome the current unmet needs mainly related to safety issues and long-term efficacy, as well as adherence to the treatment and improvement of health-related quality of life. In this perspective, alternative routes of administration and adjunctive treatments are under investigation.

SUMMARY

The future of food allergy management is a personalised approach based on a shared decision-making that takes into account the needs of patients and families. Health professionals will be able to offer multiple treatment options, including FA-AIT with adjunctive or alternative therapies. Thus, patients should be correctly identified, using validated predictive factors, in order to select appropriate candidates for these therapies.

Manufacturing processes of peanut (Arachis hypogaea) allergen powder-dnfp

Background

Important components of drug safety, efficacy, and acceptability involve manufacturing and testing of the drug substance and drug product. Peanut flour sourcing/processing and manufacturing processes may affect final drug product allergen potency and contamination level, possibly impacting drug safety, quality, and efficacy. We describe key steps in the manufacturing processes of peanut (Arachis hypogaea) allergen powder-dnfp (PTAH; Palforzia®), a drug used in oral immunotherapy (OIT) for the treatment of peanut allergy.

Methods

Established criteria for source material must be met for manufacturing PTAH drug product. Degree of roasting was determined with a Hunter colorimeter. Protein/allergen content, identity, potency, safety, and quality of each batch of PTAH drug substance were assessed with a combustion analyzer, allergen-specific Western blot (immunoblotting), ELISA, and HPLC. Contaminants (ie, aflatoxin) were measured by UPLC.

Results

Roasting degree beyond "light roast" was associated with variable degrees of protein allergen degradation, or potentially aggregation. Relative potency and amounts of protein allergens showed variability due in part to seasonal/manufacturing variability. Proportion of lots not meeting aflatoxin limits has increased in recent years. Up to 60% of peanut flour source material failed to meet screening selection acceptance criteria for proceeding to drug substance testing, mostly because of failure to meet potency acceptance criteria. Other lots were rejected due to safety (ie, aflatoxin) and quality. Influence of potency variation, within specification parameters, on safety/tolerability observed in trials was considered low, in part due to stringent controls placed at each step of manufacturing.

Conclusions

Extensive variability in allergen potency is a critical issue during immunotherapy, particularly during OIT initial dose escalation and up-dosing, as it may result in lack of efficacy or avoidable adverse allergic reactions. Based on EU and US regulatory requirements, the production of PTAH includes manufacturing controls to ensure drug product safety, potency, and quality. For example, although PTAH contains all peanut allergens, each lot has met strict criteria ensuring consistent allergenic potency of Ara h 1, Ara h 2, and Ara h 6. The rigor of PTAH's manufacturing process ensures reliable dose consistency and stability throughout its shelf life.

Allergic Inflammation: Effect of Propolis and Its Flavonoids

The incidence of allergic diseases and their complications are increasing worldwide. Today, people increasingly use natural products, which has been termed a "return to nature". Natural products with healing properties, especially those obtained from plants and bees, have been used in the prevention and treatment of numerous chronic diseases, including allergy and/or inflammation. Propolis is a multi-component resin rich in flavonoids, collected and transformed by honeybees from buds and plant wounds for the construction and adaptation of their nests. This article describes the current views regarding the possible mechanisms and multiple benefits of flavonoids in combating allergy and allergy-related complications. These benefits arise from flavonoid anti-allergic, anti-inflammatory, antioxidative, and wound healing activities and their effects on microbe-immune system interactions in developing host responses to different allergens. Finally, this article presents various aspects of allergy pathobiology and possible molecular approaches in their treatment. Possible mechanisms regarding the antiallergic action of propolis on the microbiota of the digestive and respiratory tracts and skin diseases as a method to selectively remove allergenic molecules by the process of bacterial biotransformation are also reported.

Anaphylaxis in Children

ABSTRACT

Anaphylaxis is a potentially life-threatening event in children, commonly encountered in the prehospital and emergency department settings. Recently published clinical guidelines emphasize early recognition of anaphylaxis and administration of epinephrine as the mainstay of management. Literature regarding adjuvant therapies, biphasic reactions, observation times, and disposition of patients with anaphylaxis remains controversial. In this article, we will review the background and pathophysiology of anaphylaxis, as well as the diagnostic approach, management, and future directions of anaphylaxis in children.

Food allergy: History, definitions and treatment approaches

Allergen-specific immunotherapy for the treatment of immunoglobulin E mediated food allergies, specifically oral, epicutaneous, and sublingual immunotherapies, are promising options that may provide an alternative to strict avoidance of the dietary allergen. Of these potential therapies, oral immunotherapy is the furthest along in development, with strong evidence of efficacy in clinical trials, and has achieved regulatory approval. Nevertheless, oral immunotherapy may not be a suitable therapy for some patients due to the risk of adverse effects. In contrast to oral immunotherapy, epicutaneous and sublingual immunotherapies have demonstrated modest efficacy in clinical trials, with a favorable adverse effect profile, which suggests that these therapies may be possible contenders to oral immunotherapy in certain clinical situations. Familiarity with the various treatment approaches is vital for guiding patients and families as more therapeutic modalities become available for use outside of the research setting.

Proteomic Analysis of Oil-Roasted Cashews Using a Customized Allergen-Focused Protein Database

Cashews are one of the most prevalent causes of tree nut allergies. However, the cashew proteome is far from complete, which limits the quality of peptide identification in mass spectrometric analyses. In this study, bioinformatics tools were utilized to construct a customized cashew protein database and improve sequence quality for proteins of interest, based on a publicly available cashew genome database. As a result, two additional isoforms for cashew 2S albumins and five other isoforms for cashew 11S proteins were identified, along with several other potential allergens. Using the optimized protein database, the protein profiles of cashew nuts subjected to different oil-roasting conditions (139 and 166 °C for 2-10 min) were analyzed using discovery LC-MS/MS analysis. The results showed that the cashew 2S protein is most heat-stable, followed by 11S and 7S proteins, though protein isoforms might be affected differently. Preliminary target peptide selection indicated that out of the 29 potential targets, 18 peptides were derived from the newly developed database. In the evaluation of thermal processing effects on cashew proteins, several Maillard reaction adducts were also identified. The cashew protein database developed in this study allows for comprehensive analyses of cashew proteins and development of high-quality allergen detection methods.

Lipid Ligands and Allergenic LTPs: Redefining the Paradigm of the Protein-Centered Vision in Allergy

Lipid Transfer Proteins (LTPs) have been described as one of the most prevalent and cross-reactive allergen families in the general population. They are widely distributed among the plant kingdom, as well as in different plant organs ranging from pollen to fruits. Thus, they can initiate allergic reactions with very different outcomes, such as asthma and food allergy. Several mouse models have been developed to unravel the mechanisms that lead LTPs to promote such strong sensitization patterns. Interestingly, the union of certain ligands can strengthen the allergenic capacity of LTPs, suggesting that not only is the protein relevant in the sensitization process, but also the ligands that LTPs carry in their cavity. In fact, different LTPs with pro-allergenic capacity have been shown to transport similar ligands, thus positioning lipids in a central role during the first stages of the allergic response. Here, we offer the latest advances in the use of experimental animals to study the topic, remarking differences among them and providing future researchers a tool to choose the most suitable model to achieve their goals. Also, recent results derived from metabolomic studies in humans are included, highlighting how allergic diseases alter the lipidic metabolism toward a pathogenic state in the individual. Altogether, this review offers a comprehensive body of work that sums up the background evidence supporting the role of lipids as modulators of allergic diseases. Studying the role of lipids during allergic sensitization might broaden our understanding of the molecular events leading to tolerance breakdown in the epithelium, thus helping us to understand how allergy is initiated and established in the individuals.

Early life host-microbe interactions in skin

Our skin is the interface through which we mediate lifelong interactions with our surrounding environment. Initial development of the skin's epidermis, adnexal structures, and barrier function is necessary for normal cutaneous microbial colonization, immune development, and prevention of disease. Early life microbial exposures can have unique and long-lasting impacts on skin health. The identity of neonatal skin microbes and the context in which they are first encountered, i.e., through a compromised skin barrier or in conjunction with cutaneous inflammation, can have additional short- and long-term health consequences. Here, we discuss key attributes of infant skin and endogenous and exogenous factors that shape its relationship to the early life cutaneous microbiome, with a focus on their clinical implications.

Targeted allergen-specific immunotherapy within the skin improves allergen delivery to induce desensitization to peanut

Aim: Epicutaneous immunotherapy (EPIT) with peanut has been demonstrated to be safe but efficacy may be limited by allergen uptake through the skin barrier. To enhance allergen uptake into the skin, the authors used peanut-coated microneedles and compared them with EPIT in a peanut allergy mouse model. Methods: Sensitized mice were treated with peanut-coated microneedles or peanut-EPIT and then challenged with peanut to determine protection. Results: Treatment with peanut-coated microneedles was safe and showed enhanced desensitization to peanut compared with peanut-EPIT administered via a similar schedule. Protection was associated with reduced Th2 immune responses and mast cell accumulation in the intestine. Conclusion: Peanut-coated microneedles have the potential to present a safe method of improving allergen delivery for cutaneous immunotherapy.

Holy Grail: the journey towards disease modification in asthma

At present, there is no cure for asthma, and treatment typically involves therapies that prevent or reduce asthma symptoms, without modifying the underlying disease. A “disease-modifying” treatment can be classed as able to address the pathogenesis of a disease, preventing progression or leading to a long-term reduction in symptoms. Such therapies have been investigated and approved in other indications, e.g. rheumatoid arthritis and immunoglobulin E-mediated allergic disease. Asthma's heterogeneous nature has made the discovery of similar therapies in asthma more difficult, although novel therapies (e.g. biologics) may have the potential to exhibit disease-modifying properties. To investigate the disease-modifying potential of a treatment, study design considerations can be made, including: appropriate end-point selection, length of trial, age of study population (key differences between adults/children in physiology, pathology and drug metabolism) and comorbidities in the patient population. Potential future focus areas for disease-modifying treatments in asthma include early assessments (e.g. to detect patterns of remodelling) and interventions for patients genetically susceptible to asthma, interventions to prevent virally induced asthma and therapies to promote a healthy microbiome. This review explores the pathophysiology of asthma, the disease-modifying potential of current asthma therapies and the direction future research may take to achieve full disease remission or prevention.

Asthma is a complex, heterogeneous disease, which currently has no cure; this review explores the disease-modifying potential of asthma therapies and the direction future research may take to achieve disease remission or prevention.https://bit.ly/31AxYou

Masked Delivery of Allergen in Nanoparticles Safely Attenuates Anaphylactic Response in Murine Models of Peanut Allergy

Food allergy is a growing health concern worldwide. Current allergen-specific immunotherapy (AIT) approaches require frequent dosing over extended periods of time and may induce anaphylaxis due to allergen-effector cell interactions. A critical need remains to develop novel approaches that refine AIT for the treatment of food allergies. Previous studies show that poly(lactide-co-glycolide) (PLG) nanoscale particles (NP) effectively suppress Th1- and Th17-driven immune pathologies. However, their ability to suppress the distinct Th2-polarized immune responses driving food allergy are unknown. Herein, we describe the safety and efficacy of NPs containing encapsulated peanut allergen in desensitizing murine models of peanut allergy. Peanut extract encapsulation allowed for the safe intravenous delivery of allergen relative to non-encapsulated approaches. Application of 2–3 doses, without the need for dose escalation, was sufficient to achieve prophylactic and therapeutic efficacy, which correlated with suppression of Th2-mediated disease and reduced mast cell degranulation. Efficacy was associated with strong reductions in a broad panel of Th1, Th2, and Th17 cytokines. These results demonstrate the ability of PLG NPs to suppress allergen-specific immune responses to induce a more tolerogenic phenotype, conferring protection from intragastric allergen challenge. These promising studies represent a step forward in the development of improved immunotherapies for food allergy.

Immunologic and pathologic characterization of a novel swine biomedical research model for eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic allergy-mediated condition with an increasing incidence in both children and adults. Despite EoE's strong impact on human health and welfare, there is a large unmet need for treatments with only one recently FDA-approved medication for EoE. The goal of this study was to establish swine as a relevant large animal model for translational biomedical research in EoE with the potential to facilitate development of therapeutics. We recently showed that after intraperitoneal sensitization and oral challenge with the food allergen hen egg white protein (HEWP), swine develop esophageal eosinophilia-a hallmark of human EoE. Herein, we used a similar sensitization and challenge treatment and evaluated immunological and pathological markers associated with human EoE. Our data demonstrate that the incorporated sensitization and challenge treatment induces (i) a systemic T-helper 2 and IgE response, (ii) a local expression of eotaxin-1 and other allergy-related immune markers, (iii) esophageal eosinophilia (>15 eosinophils/0.24 mm²), and (iv) esophageal endoscopic findings including linear furrows and white exudates. Thereby, we demonstrate that our sensitization and oral challenge protocol not only induces the underlying immune markers but also the micro- and macro-pathological hallmarks of human EoE. This swine model for EoE represents a novel relevant large animal model that can drive translational biomedical research to develop urgently needed treatment strategies for EoE.

Oral Immunotherapy for Children with Cow's Milk Allergy

Cow's milk allergy (CMA) is one of the most common IgE-dependent food allergies in children. Some children develop severe and persistent CMA, with near-fatal reactions after exposure to trace amounts of cow's milk (CM). Because milk and dairy products are included in various processed food products, it is difficult to completely remove milk, which negatively affects the quality of life of children with CMA. Oral immunotherapy (OIT) can alleviate food allergen-induced anaphylaxis under continuous ingestion of a little of the causative food. Children with severe CMA may benefit from OIT, but the treatment requires a long time and poses a risk of anaphylaxis. Moreover, in recent years, new therapies, including omalizumab, sublingual immunotherapy, and epicutaneous immunotherapy, have played the role of optional OIT. In this review, we present the current methods of and other attempts at OIT, and discuss OIT for safely treating CMA.

Clinical Manifestations of Pediatric Food Allergy: a Contemporary Review

Food allergies (FAs) are an emerging health care issue, and a "second wave of the allergy epidemic" was named. There are extensive data that documented the prevalence rate as high as approximately 10%. FAs are immunological adverse reactions, including IgE-mediated mechanisms, cell-mediated mechanisms, or mixed IgE- and cell-mediated mechanisms. A diagnosis of FA is made by specific symptoms encounter with food, detailed past history, sensitization tests, and oral food challenges (OFCs) if necessary. The component-resolved diagnostics (CRD) test can distinguish true or cross-reaction. "Minimal elimination" from the results of CRD and OFC could avoid unnecessary food restriction. Strict food limitation is harsh and stressful on patients and their families. Children with FAs experience a higher rate of post-traumatic stress symptoms (PTSS) and bullying than others. In the last 20 years, oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) are treatment strategies. OIT and EPIT are the most two encouraging treatments for FA. This review aims to introduce FAs in diverse clinical disorders, new perspectives, and their practical implications in diagnosing and treating FA.

Changes in epidemiology and clinical practice in IgE-mediated Allergy in children

In the last decades, allergic diseases have increased exponentially and although pediatric asthma prevalence is stabilizing, it is estimated around 10% in Spain. Not the same with food allergy and anaphylaxis which are clearly increasing, becoming a significant public health problem. Taking into account epidemiological trends, the European Academy of Allergy and Clinical Immunology (EAACI) estimates that in less than 15 years more than half of the European population will suffer from some type of allergic disorder. The advances in diagnostic methods in food allergy, especially component resolved diagnosis, allow us to know the patient's sensitization profile and explain possible cross reactivity, anticipate potential risk of food trangressions, and prescribe correct avoidance diet in each patient. Thus, the development of molecular biology and nanotechnology have led to the appearance of new technologies (microarrays) which facilitate the study, specially of the polysensitized patients, allowing allergen immunotherapy (AIT) to be more personalized. The latest advances in the use of biologics are having an impact, not only in disease evolution, but also in quality of life.

[Changes in epidemiology and clinical practice in IgE-mediated allergy in children]

In the last decades, allergic diseases have increased exponentially and although pediatric asthma prevalence is stabilizing, in Spain is estimated around 10%. Not the same with food allergy and anaphylaxis which are clearly increasing, becoming a public health problem of the first magnitude. Considering epidemiological trends, the European Academy of Allergy and Clinical Immunology (EAACI) estimates that in less than 15 years more than half of European population will suffer from some type of allergy. The advances in diagnostic methods in food allergy, especially component resolved diagnosis, allow us to know the patient's sensitization profile and explain the possible cross reactivity, anticipate potential risk of food transgressions, and prescribe the correct avoidance diet in each patient. Thus, the development of molecular biology and nanotechnology have led to the appearance of new technologies (microarrays) which facilitate the study, specially of the polysensitized patients, allowing allergen immunotherapy (AIT) to be more personalized. The latest advances in the use of biologics are having an impact, not only in disease evolution, but also in patients quality of life.

Regulatory Requirements for the Quality of Allergen Products for Allergen Immunotherapy of Food Allergy

Purpose of Review

Medicinal products for allergen immunotherapy (AIT) of food allergies have gained enormous momentum in recent years. With this new class of products entering marketing authorization procedures, compliance to regulatory requirements becomes a critical element. Here, an overview is provided on specific requirements and aspects concerning the quality control and manufacturing of these products.

Recent Findings

Recent developments in the field of AIT for food allergies are divers, including products for oral, epicutaneous, and subcutaneous application, most notably targeting egg, milk, and peanut allergy. As the source materials for food AIT product are typically produced for food consumption and not for medicinal purposes, unique challenges arise in the manufacturing processes and controls of these medicinal products. Individual approaches are needed to assure acceptable quality, including control of relevant quantitative and qualitative characteristics. Major characteristics for quality verification include determination of protein content, total allergenic activity, and major allergen content. The applied manufacturing processes need to be established such that relevant process parameters are kept within justified limits and consistency of produced batches is assured.

Summary

Allergen products for food AIT present specific challenges with respect to quality aspects that differentiate them from other commonly available AIT products. While established regulation is available and provides clear guidance for most aspects, other issues require consideration of new and individual settings relevant here. Consequently, as experience grows, respective amendments to currently available guidance may be needed.

Update on food allergy

Food allergy is a major public health issue with growing prevalence in the urbanized world and significant impact on the lives of allergic patients and their families. Research into the risk factors that have contributed to this increase and their underlying immune mechanisms could lead us to definitive ways for treatment and prevention of food allergy. For the time being, introduction of peanut and other allergenic foods in the diet at the time of weaning seems to be an effective way to prevent the development of food allergy. Improved diagnosis and appropriate management and support of food allergic patients are central to patient care with food immunotherapy and biologics making the transition to clinical practice. With the new available treatments, it is becoming increasingly important to include patients' and family preferences to provide a management plan tailored to their needs.

The Use of Bruton's Tyrosine Kinase Inhibitors to Treat Allergic Disorders

Purpose of review

Studies show that inhibitors of Bruton’s tyrosine kinase (BTKis), currently FDA-approved for the treatment of B cell malignancies, can prevent IgE-mediated reactions through broad inhibition of the FcεRI signaling pathway in human mast cells and basophils. This review will summarize recent data supporting the use of these drugs as novel therapies in various allergic disorders.

Recent findings

Recent studies have shown that BTKis can prevent IgE-mediated degranulation and cytokine production in primary human mast cells and basophils. Two oral doses of the second-generation BTKi acalabrutinib can completely prevent moderate passive systemic anaphylaxis in humanized mice and even protect against death during severe anaphylaxis. Furthermore, two doses of ibrutinib can reduce or eliminate skin prick test responses to foods and aeroallergens in allergic subjects. BTKis in development also show efficacy in clinical trials for chronic urticaria. Unlike other therapies targeting IgE, such as omalizumab, BTKis appear to have rapid onset and transient effects, making them ideal candidates for intermittent use to prevent acute reactions such as IgE-mediated anaphylaxis.

Summary

These studies suggest that BTKis may be capable of preventing IgE-mediated anaphylaxis, paving the way for future trials in food allergy and urticaria.

Oral immunotherapy in food allergies: A practical update for pediatricians

Food oral immunotherapy (OIT) is a promising treatment for persistent and severe food allergies (FAs) in children, but also for accelerating tolerance to cow's milk and cooked egg in young children. In the near future, pediatricians will increasingly encounter severely allergic children undergoing FA-OIT. FA-OIT consists in daily ingestion of increasing doses of the allergen during the up-dosing phase, and ingestion of a constant dose during the maintenance phase. The global aim is to increase the reactive threshold of allergic patients, and finally enable them to ingest a target quantity of allergen without any reaction throughout the treatment (desensitization). Many studies showed the efficacy of FA-OIT in desensitization, and some of them in sustained unresponsiveness. This corresponds to tolerance after FA-OIT discontinuation, especially for cow's milk and hen's egg allergy. However, there is an ongoing debate about the safety of the treatment. Side effects are frequent, notably aversion to the allergen and oral syndromes as well as systemic allergic symptoms. These reactions occur mainly during the up-dosing phase and become less frequent with time, but they are common causes of FA-OIT discontinuation. Patients and their families must be trained to manage these reactions at home. Long-term side effects can also occur, such as eosinophilic esophagitis. Pediatricians play an important role in maintaining patient motivation; they also provide knowledge on possible allergic reactions and the reactogenic cofactors (mainly fever and viral infection, anti-inflammatory intake, physical activity), and refer the patient to the relevant specialists in the case of long-term care. Other routes of administration for food immunotherapy (epicutaneous and sublingual) and different adjuvant treatments (probiotics, anti-IgE molecule) are currently under study. This will allow us to improve the efficacy of immunotherapy and reduce the risk of any side effects, in order to provide a more favorable risk-benefit ratio.

Epicutaneous immunotherapy protects cashew-sensitized mice from anaphylaxis

Background

The prevalence of tree nut allergy has increased worldwide, and cashew has become one of the most common food allergens. More critically, cashew allergy is frequently associated with severe anaphylaxis. Despite the high medical need, no approved treatment is available and strict avoidance and preparedness for prompt treatment of allergic reactions are considered dual standard of care. In the meantime, Phase III study results suggest investigational epicutaneous immunotherapy (EPIT) may be a relevant and safe treatment for peanut allergy and may improve the quality of life for many peanut allergic children.

Objective

We aimed to evaluate the capacity of EPIT to provide protection against cashew‐induced anaphylaxis in a relevant mouse model.

Methods

The efficacy of EPIT was evaluated by applying patches containing cashew allergens to cashew‐sensitized mice. As negative control, sham mice received patches containing excipient. Following treatment, mice were challenged orally to cashew and anaphylactic symptoms, as well as plasmatic levels of mast‐cell proteases (mMCP)‐1/7, were quantified.

Results

Of 16 weeks of EPIT significantly protects against anaphylaxis by promoting a faster recovery of challenged mice. This protection was characterized by a significant reduction of temperature drop and clinical symptoms, 60 minutes after challenge. This was associated with a decrease in mast‐cell reactivity as attested by the reduction of mMCP‐1/7 in plasma, suggesting that EPIT specifically decrease IgE‐mediated anaphylaxis.

Conclusion

We demonstrate that EPIT markedly reduced IgE‐mediated allergic reactions in a mouse model of cashew allergy, which suggests that EPIT may be a relevant approach to treating cashew allergy.

Mechanisms of oral immunotherapy

Food allergy presents a significant global health concern with up to 10% of the population affected in developed nations and a steadily increasing prevalence. In many cases, particularly with peanut, tree nut and shellfish, food allergy is a lifelong and potentially life-threatening diagnosis. While no 'cure' for IgE-mediated food allergy exists, oral immunotherapy (OIT) is a promising treatment modality with the peanut OIT drug Palforzia (Aimmune Therapeutics) the only treatment for food allergy that is currently approved by the United States Food and Drug Administration. OIT primarily induces a state of desensitization with only a minority of subjects achieving sustained unresponsiveness, a state of limited clinical remission that appears to be immunologically distinct from natural tolerance. Early humoural changes during OIT include an initial increase in allergen-specific IgE, which eventually decreases to below baseline levels as OIT progresses, and a gradual increase in allergen-specific IgA and IgG4 that continues throughout the course of OIT. Basophil hyporesponsiveness and decreased skin prick test wheal size are observed within the first year of OIT, and persistence after completion of therapy has been associated with sustained unresponsiveness. In the T-cell compartment, there is an initial expansion followed by a decline in the number and activity of T helper 2 (TH 2) cells, the latter of which may be dependent on an expansion of IL-10-producing cells, including regulatory T-cells. Our understanding of the immunomodulatory effects of OIT continues to evolve, with new technologies such as single-cell transcriptional profiling and antibody epitope analysis allowing for more detailed study of T-cell and B-cell responses to OIT. In this review, we present evidence to illustrate what is currently known about the immunologic changes induced by OIT, explore potential mechanisms and emphasize knowledge gaps where future research is needed.

Vaccines as therapies for food allergies

Food allergy is a growing public health epidemic with few available treatments beyond allergen avoidance and rescue medications for accidental exposures. A major focus of therapeutic development for food allergies is allergen-specific immunotherapy (AIT) in which patients are exposed to increasing amounts of allergen in controlled dosing to induce desensitization or tolerance. The work of the past few decades has culminated in the recent FDA approval of a peanut product for oral AIT for peanut allergies. Despite these advances, current AIT protocols are cumbersome, take a long time to reach clinical benefit and often have significant side effects. Therefore, there is a great need to develop new therapeutics for food allergy. One area of research aims to improve AIT through the use of adjuvants which are substances traditionally added to vaccines to stimulate or direct a specific immune response. Adjuvants that induce Th1-polarized and regulatory immune responses while suppressing Th2 immunity have shown the most promise in animal models. The addition of adjuvants to AIT may reduce the amount and frequency of allergen required to achieve clinical benefit and may induce more long-lasting immune responses. In this chapter, we highlight examples of adjuvanted AIT and vaccines in development to treat food allergies.

Gastrointestinal Food Allergies and Intolerances

Adverse reactions to food include immune-mediated food allergies, celiac disease, and nonimmune-mediated food intolerances. Differentiating between these many disorders is important to guide us toward appropriate testing and management. Double-blind placebo-controlled food challenges are the gold standard for food allergy diagnosis but are difficult and time-consuming. In place of this, strong clinical history, other supportive tests, and oral food challenges are helpful. Some commonly available tests for food allergy and intolerances lack sufficient evidence for efficacy. Food intolerance diagnosis is largely based on history and supported by symptom improvement with appropriate dietary manipulation.

Integrating oral immunotherapy into clinical practice

In 2020, the first food allergy treatment, an oral immunotherapy (OIT) product for peanut allergy, was approved by the Food and Drug Administration, and a peanut epicutaneous immunotherapy patch was under review. As food allergy therapies become available and widespread, allergy offices will need to adjust practices to be able to offer their patients these new treatments. OIT is an intensive therapy that requires commitment from patients and their families, and open communication with the practice is paramount. OIT may not be the right therapy for every patient, and although identifying good candidates is still an area rich for research opportunity, experience from cohorts and clinical trials provides some insight. It is important to understand the scope of practice for each member of the OIT team based on state regulations for a particular location. Staffing and space will likely dictate how many patients at an individual office could be on active OIT at one time. Emergency medications, supplies, and protocols must be in place. Screening, scheduling, visit procedures, monitoring, home dosing, dose modifications, safety precautions, adverse reactions, and maintenance will be addressed in this article. Finally, adjunct therapies under investigation will be reviewed.

Strategies for Mast Cell Inhibition in Food Allergy

Mast cells are tissue resident allergic effector cells that drive IgE-mediated food allergies. There are several steps leading to mast cell activation in the context of allergic disease that can be targeted to prevent mast cell activation and degranulation. These include blocking IgE-FcεRI crosslinking and type 2 cytokine receptor activation; modulating cell-surface neural chemical receptors; stabilizing mast cell membranes to prevent co-localization of activating receptors; impeding intracellular signaling; and engaging cell surface inhibitory receptors. This review highlights several ITIM-containing inhibitory mast cell surface receptors that could serve as pharmaceutical targets to prevent mast cell activation and degranulation in the context of food allergy. When activated, these ITIM-containing inhibitory receptors recruit the phosphatases SHP-1, SHP-2, and/or SHIP to dephosphorylate the tyrosine kinases responsible for activation signals downstream of the IgE-FcεRI complex. We describe several members of the Ig and Ig-like inhibitory receptor and C-type lectin inhibitory receptor superfamilies. Fundamental studies exploring the behavior of these receptors within the context of experimental food allergy models are needed. A deeper understanding of how these receptors modulate mast cell-driven food allergic responses will shape future strategies to harness these inhibitory receptors to treat food allergy.