Oral immunotherapy for treatment of egg allergy in children

Re-evaluating treatment success in trials of peanut oral-immunotherapy: impact of different definitions on efficacy outcomes

PURPOSE OF REVIEW

Allergen immunotherapy (AIT) is increasingly popular as a treatment strategy for food allergy. Unfortunately, there is significant heterogeneity in reported outcomes, specifically in the dose-thresholds selected for evaluation and the symptoms used to define a "tolerated dose". These considerations are often investigator-driven and do not consider patient perspectives.

RECENT FINDINGS

A systematic review by the EAACI CO-FAITH taskforce recently flagged the need to better standardize and harmonize outcomes used in clinical trials of food-AIT. Using less objective symptoms to define dose-limiting symptoms can underestimate the reaction threshold determined at baseline food challenge. As a consequence, this can overestimate the efficacy of food-AIT by 15%. In this review, we perform an individual patient data (IPD) meta-analysis using data from three randomized-controlled trials and one real-world registry, to evaluate how the definition of dose "tolerance" impacts upon reported desensitization rates.

SUMMARY

This analysis provides insight into how clinical efficacy rates for food-AIT are impacted by using different dose thresholds and definitions for when a dose might be consider tolerated. Using more patient-centric outcomes may be a more useful metric to harmonize reporting of outcomes and inform clinical practice, paving the way towards reaching a consensus on outcome reporting in trials of food-AIT.

Elucidation of Desensitization Mechanisms Induced by Oral Immunotherapy in a Rat Model of Ovalbumin Allergy

Oral immunotherapy (OIT) is a promising approach for treating food allergy. Here, we elucidated the mechanisms of desensitization induced by OIT in rats sensitized to ovalbumin (OVA). The desensitization was induced by ingestion of OVA three times per week after sensitization in rats. OIT suppressed the decrease in rectal temperature and increase in plasma histamine levels induced by OVA injection immediately and 4 weeks after OIT completion. Plasma OVA-specific IgE (sIgE) levels did not differ between the non-OIT and OIT groups, but OVA-specific IgG1 levels were higher in the OIT group than in the non-OIT group at both timepoints. To evaluate IgG's effect on IgE crosslinking with OVA, amplified luminescence proximity homogeneous assay involving crosslinking (AlphaCL) was performed. When IgG was removed using a Protein G column, the AlphaCL signal was significantly increased, especially in the OIT group, indicating that OIT-induced IgG inhibited the sIgE response. The proportions of cluster of differentiation (CD)4+ cells and CD4+CD25+FoxP3+ cells in mesenteric lymph nodes and spleen were similar between the two groups. These findings indicate that OIT attenuates systemic allergic responses by inhibiting sIgE binding to OVA through increased IgG. Our model is useful for understanding the mechanisms of OIT and optimizing therapeutic strategies for ameliorating food allergies.

Evolving Food Allergy Clinical Trials to Become More Patient-Centered

The current US Food and Drug Administration (FDA) paradigm may not fully capture important patient-centered outcomes or measure a primary outcome that is truly meaningful to patients. Patient-reported outcome measures (PROMs) are standardized tools measuring the patient's experience in food allergy clinical trials, which can help support shared decision-making (SDM) and further our understanding of treatment impact. Food allergy PROMs include quality of life (QoL), health state utility (HSU), severity, and self-efficacy measures. Currently, FDA registration trials for product approval only consider a fixed increase in allergen threshold from pre-to-post intervention as a primary outcome (vs a more flexible "X-fold" increase not accounting for an upper and lower specific threshold), though many use QoL as a secondary outcome for patient-centered assessment of treatment impact. Currently used QoL PROMs were not designed to measure change on therapy nor measure HSU (eg, quantitative risk a patient may be willing to take to improve their current health), which can be used to determine therapy value. Although the current paradigm for primary and secondary outcomes in food allergy clinical trials was appropriate at the early stages of food allergy therapy development when conceived in the late 2000s and early 2010s, in the 2020s, these outcome choices risk being stagnant and outdated. As such, the current paradigm for food allergy outcomes should evolve to incorporate more patient-centered primary outcome measures that patient data indicate are meaningful, so outcomes more realistically reflect a therapy's impact. This evolution will better support SDM discussions as patients consider their therapy options and can inform new product development.

Efficacy of omalizumab in food allergic adults - A retrospective analysis

Background

IgE-mediated food allergy poses a significant public health concern, currently with no approved therapies for adults in Europe. Omalizumab (OMA) used as monotherapy or in conjunction with oral immunotherapy (OIT) has been suggested as an efficacious treatment for severe food allergy. The aim of this study was to analyze real-world data from food-allergic patients treated with OMA.

Methods

We included food-allergic patients treated with OMA between 2002 and 2022 throughout Europe. Treatment responders (TR) were identified based on the unresponsiveness to related food allergens (determined by food challenge), reduction in the severity of food allergy and absence of anaphylactic reactions.

Results

Sixty-two patients (female n = 39/62, 62.9%; mean age 30.6 years) were included into this analysis, most of whom were polysensitized to more than 2 food allergens (n = 40/62, 64.5%); 45/62 patients (72.6%) received OMA in conjunction with OIT, while the remaining patients underwent OMA monotherapy. The eliciting food allergens were tree nuts (n = 27/62, 43.5%), cow's milk (n = 26/62, 41.9%), and vegetables (n = 25/62, 40.3%). In most cases, OMA was initiated with 300 mg q4w (n = 51/62, 82.3%) dosing. Treatment was tolerated exceptionally well.Fifty-two (52/62) patients (83.9%) were classified as treatment responders. Six (6/62) patients (9.7%) developed unresponsiveness, 6/62 (9.7%) had a reduction of the severity of food allergy, and 40/62 (64.5%) had no further anaphylactic reactions during treatment. One (1/62) patient (1.6%) undergoing monotherapy was a non-responder, exhibiting repeated anaphylactic reactions to accidental exposures, and 10/62 patients (16.1%) reported anaphylactic reactions during treatment. In most of these cases, cofactors (n = 5/10, 50%) were present.

Conclusion

Our real-world evidence data indicate efficacy and tolerability of OMA for the treatment of IgE-mediated food allergy with and without OIT. As the onset of food related reactions upon treatment was frequently linked to the presence of cofactors, these should be identified and considered in patients with food allergy-not only for diagnosis, but also in treatment settings.

Treatment of Food Allergy: Immunotherapy, Omalizumab, or Both

Food allergy is a common disease that has substantial impacts on the quality of life of patients and their families, and all reactions have the potential for causing life-threatening anaphylaxis. Food-allergic individuals currently have 2 Food and Drug Administration- approved therapeutic options available to them aside from life-long allergen avoidance: oral immunotherapy (OIT) and omalizumab. OIT for food allergy has been extensively studied in clinical trials and currently provides the greatest level of protection; however, it also has a high burden of treatment. Studies suggest that more successful OIT outcomes may be attained with earlier intervention; however, early OIT presents its own challenges. Omalizumab, recently Food and Drug Administration-approved, is a biologic targeting IgE, a major driver of allergic reactions. In contrast to OIT, omalizumab monotherapy offers a low treatment burden therapeutic option that provides a safety net against reactions to accidental ingestion of multiple allergens. In addition, omalizumab has been investigated as an adjunct to OIT, improving the speed and safety of single-allergen or multiallergen OIT. Here, we discuss the clinical use of these therapeutic options and provide a guide for shared decision making between patients and physicians about what therapeutic option might be more appropriate.

Antigen Uptake in the Gut: An Underappreciated Piece to the Puzzle?

The mammalian gut is a vast, diverse, and dynamic single-layer epithelial surface exposed to trillions of microbes, microbial products, and the diet. Underlying this epithelium lies the largest collection of immune cells in the body; these cells encounter luminal substances to generate antigen-specific immune responses characterized by tolerance at homeostasis and inflammation during enteric infections. How the outcomes of antigen-specific tolerance and inflammation are appropriately balanced is a central question in mucosal immunology. Furthermore, how substances large enough to generate antigen-specific responses cross the epithelium and encounter the immune system in homeostasis and during inflammation remains largely unexplored. Here we discuss the challenges presented to the gut immune system, the identified pathways by which luminal substances cross the epithelium, and insights suggesting that the pathways used by substances to cross the epithelium affect the ensuing immune response.

Omalizumab and Oral Immunotherapy in IgE-Mediated Food Allergy in Children: A Systematic Review and a Meta-Analysis

Background: Food allergies are a growing global health concern, particularly among children, with no widely approved curative treatment beyond strict allergen avoidance. Oral immunotherapy (OIT) has emerged as a promising strategy to induce desensitization, yet its implementation is limited due to high rates of allergic reactions and patient non-compliance. Omalizumab, a monoclonal anti-IgE antibody, has been proposed as an adjunct to OIT to enhance safety and efficacy. Objective: This systematic review and meta-analysis aim to evaluate the efficacy and safety of omalizumab in combination with OIT for IgE-mediated food allergy in children. Methods: A systematic literature search was conducted in PubMed/MEDLINE and Cochrane Central databases to identify randomized controlled trials (RCTs), controlled clinical trials (CCTs), and observational studies assessing omalizumab as an adjunct to OIT in pediatric food allergy. Studies were evaluated for desensitization rates, immunological changes, adverse events, and quality-of-life improvements. Results: OIT combined with omalizumab led to significantly higher rates of desensitization, allowing patients to tolerate higher doses of allergens in a shorter timeframe compared to OIT alone. Omalizumab was associated with a reduction in adverse reactions, including anaphylaxis, and improved treatment adherence. However, the long-term sustainability of tolerance post-omalizumab discontinuation remains uncertain. Conclusions: Omalizumab facilitates rapid and effective desensitization in pediatric food allergy, enhancing the safety of OIT. Further research is needed to determine optimal treatment duration, long-term outcomes, and cost-effectiveness before widespread clinical adoption.

Dupilumab as an Adjunct to Oral Immunotherapy in Pediatric Patients With Peanut Allergy

BACKGROUND

Peanut allergy is a common, life-threatening food allergy in children. We evaluated whether dupilumab, which blocks the activity of interleukin (IL)-4/IL-13, enhances the efficacy of oral immunotherapy (OIT) AR101 in pediatric patients with peanut allergy.

METHODS

A Phase II, multicenter, randomized, double-blind study was conducted in the USA (NCT03682770) in pediatric patients (6-≤ 17 years old) with confirmed peanut allergy. Patients were randomized 2:1 to receive dupilumab + OIT or placebo + OIT during a 28-40-week up-dosing period. Patients in the dupilumab + OIT group were re-randomized 1:1 and received dupilumab + OIT or placebo + OIT during 24-week OIT maintenance, undergoing a 2044 mg (cumulative) of peanut protein double-blind, placebo-controlled food challenge (DBPCFC) following up-dosing, maintenance, and at 12-week post-treatment follow-up.

RESULTS

The study enrolled 148 patients, 123 of whom were included in the modified full analysis set, with a mean age of 11.1 years. Dupilumab + OIT treatment (n = 84) led to a 20.2% increase (p < 0.05) in the number of patients who passed a DBPCFC to 2044 mg (cumulative) of peanut protein following the up-dosing period versus placebo (OIT alone, n = 39). Following the OIT maintenance period, continuous dupilumab treatment improved the number of patients who passed a DBPCFC to 2044 mg (cumulative) of peanut protein versus patients continuously on OIT alone (16.6% difference [95% CI -9.7, 42.8], p = 0.2123). Safety was consistent with known dupilumab safety profile.

CONCLUSIONS

Dupilumab provided a modest increase efficacy of OIT in children and adolescents with peanut allergy, though it did not provide protection against OIT-related anaphylaxis.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03793608.

Food oral immunotherapy

Food oral immunotherapy (OIT) is an option for the treatment of immunoglobin E (IgE)-mediated food allergy that involves administering gradually increasing doses of an allergenic food over time (under medical supervision) with the goal of desensitizing an individual to the food allergen. Current Canadian clinical practice guidelines for OIT recommend this form of therapy as an option in patients with food allergy. The intervention should be prioritized in the infant and toddler population, in which it is particularly well tolerated and can lead to sustained unresponsiveness (also sometimes referred to as remission). In this article, we provide an overview of OIT and discuss the role non-allergist clinicians can play in caring for patients undergoing OIT.

ADP101 multifood oral immunotherapy for food-allergic patients: Harmony phase 1/2 randomized clinical trial

Background

Oral immunotherapy is an established approach to desensitize the immune system in the context of allergic disease; however, the only currently approved product is for peanut allergy. ADP101 is a novel, pharmaceutical-grade, multifood oral immunotherapy in development to simultaneously treat single or multiple food allergies, containing allergenic proteins from 15 foods in equal parts by protein weight.

Objective

The phase 1/2 Harmony trial (NCT04856865) evaluated efficacy and safety of ADP101 in participants with qualifying allergy to 1 to 5 foods in ADP101, defined as dose-limiting symptoms with a ≤100 mg challenge dose during double-blind, placebo-controlled food challenge (DBPCFC).

Methods

Participants were randomized to low-dose (1500 mg/d; 100 mg protein per food) or high-dose (4500 mg/d; 300 mg protein per food) ADP101, or matched placebo, with dose escalation followed by daily maintenance dosing over 40 weeks. The primary endpoint was the proportion of participants tolerating a ≥600 mg challenge dose of a single qualifying food without dose-limiting symptoms at the Week 40 Exit DBPCFC (ie, responders).

Results

In the primary analysis population (61 pediatric participants aged 4-17 years), a greater response rate was observed in both the high-dose ADP101 (55.0%) and low-dose ADP101 (38.1%) groups compared with pooled placebo (20.0%) (nominal P = .048, P = .306, respectively; adjusted for multiple comparisons, P = .097, P = .306, respectively). Desensitization to ≥2 foods was observed in individuals with multiple food allergies, as was desensitization at levels over 600 mg. ADP101-treated participants showed an overall reduction in skin-prick test reactivity, with an increase in maximum tolerated dose across the majority of foods tested. Adverse events were mostly mild or moderate, with no life-threatening events or deaths.

Conclusions

The study did not meet its primary endpoint, but ADP101 demonstrated a favorable safety profile and increased the reactive threshold in DBPCFC in pediatric participants with single or multiple food allergies across multiple endpoints, warranting further clinical investigation.

Effects of Food Processing on Allergenicity

PURPOSE OF REVIEW

There is an increasing awareness among clinicians that industrial and household food processing methods can increase or decrease the allergenicity of foods. Modification to allergen properties through processing can enable dietary liberations. Reduced allergenicity may also allow for lower risk immunotherapy approaches. This review will equip physicians, nurses, dieticians and other health care providers with an updated overview of the most clinically oriented research in this field. We summarize studies assessing the allergenicity of processed foods through clinically accessible means, such as oral food challenges, skin prick tests, and sIgE levels.

RECENT FINDINGS

Baking, boiling, canning, fermenting, pasteurizing, peeling, powdering, and roasting heterogenously impact the likelihood of reactivity in egg-, milk-, peanut- and other legume-, tree nut-, fruit-, and seafood-allergic patients. These variations may be due to the use of different temperatures, duration of processing, presence of a matrix, and the specific allergens involved, among other factors. Accurate prediction of tolerance to processed allergens with skin prick tests and sIgE levels remains largely elusive. Food allergy management strategies, especially with milk and egg, have capitalized on the decreased allergenicity of baking. Many milk- and egg-allergic patients tolerate baked and heated forms of these allergens, and the use of these processed foods in oral immunotherapy (OIT) continues to be extensively investigated. Heat is also well recognized to reduce allergic symptoms from some fruits and vegetables in food-pollen syndrome. Other forms of processing such as boiling, fermenting, and canning can reduce allergenicity to a diverse array of foods. Roasting, on the other hand, may increase allergenicity. The application of food processing to food allergy treatments remains largely unexplored by large clinical studies and provides a key avenue for future research. The recognition that food allergy represents a spectrum of hypersensitivity, rather than an all-or-nothing phenomenon, has led to approaches to enable dietary liberation with processed, less-allergenic foods and their use in food allergy immunotherapies.

Research progress and immunological insights of shrimp allergens

Allergic diseases have become a major health issue in the 21st century. The FAO has pinpointed the eight most prevalent allergens worldwide, with shrimp allergy attracting global concern due to its escalating incidence. This review delves into the current knowledge of shrimp allergen types and traits, immune response mechanisms, advancements in cross-reactivity research, and breakthroughs in diagnostic and therapeutic methods. It highlights the variety of shrimp allergens, such as tropomyosin and arginine kinase, and concentrates on IgE-mediated immediate hypersensitivity reactions, involving mast cells and basophils, alongside the role of T cells and cytokines in non-IgE-mediated delayed hypersensitivity reactions. The exploration of cross-reactivity underscores the connection between shrimp allergy and allergies to other animals. Utilizing bioinformatics tools, including homology analysis, epitope prediction, and molecular modeling, has enhanced our comprehension of allergen molecular features. In treatment and diagnosis, innovative approaches like immunotherapy and gene editing technology hold potential to decrease allergic sensitivity, while emerging reduction techniques like heat treatment and enzymatic hydrolysis offer new strategies for the prevention and management of food allergies. The evolution of allergen detection and purification technologies has spurred innovation in testing methodologies, encompassing traditional in vivo tests like SPT and DBPCFC, in addition to a range of other techniques such as immunoassays, biochip technology, PCR, and histamine release experiments, propelling the instantaneous and accurate identification of allergens. These scientific breakthroughs not only expand our understanding of shrimp allergen biology but also lay the foundation for developing more effective allergy prevention and control strategies.

Efficacy and Safety of Dupilumab in Children With Peanut Allergy: A Multicenter, Open-Label, Phase II Study

BACKGROUND

Peanut allergy is a potentially life-threatening food allergy in children. This study explored whether dupilumab, a human monoclonal immunoglobulin (Ig)G4 antibody that blocks the activity of interleukin (IL)-4/IL-13, improved safety and desensitization to peanut exposure in children with peanut allergy.

METHODS

A Phase II, 24-week, multicenter, single-arm, open-label, proof-of-concept study was conducted in the USA and Canada (NCT03793608). Children/adolescents with peanut allergy received subcutaneous dupilumab 300 mg (≥ 60 kg) or 200 mg (≥ 20 to < 60 kg) every 2 weeks. The primary endpoint was the proportion of participants who passed a double-blind placebo-controlled food challenge (DBPCFC) with ≥ 444 mg (cumulative) of peanut protein at week 24. Secondary endpoints included safety measures (Consortium of Food Allergy Research grading system) and change from baseline in peanut-specific (ps)-IgG4, total IgE, and ps-IgE.

RESULTS

Twenty-four participants enrolled and received dupilumab: 75.0% were male, 79.2% were white, mean (standard deviation) age was 11.7 (3.3) years. Most (95.8%) participants had not received allergen immunotherapy. Two participants (8.3%) achieved the primary endpoint and passed the DBPCFC at week 24. Fifteen participants (62.5%) reported 66 treatment-emergent adverse events, all being mild or in moderate intensity. At the week 24 DBPCFC, 8 participants (33.3%) had a grade 2 allergic reaction (no grade 3 or above); 10 (41.7%) used adrenaline as a rescue medication. Dupilumab treatment resulted in a median reduction of total and ps-IgE of -54% and -49%, respectively, and a 0% change in ps-IgG4.

CONCLUSIONS

Dupilumab monotherapy treatment for 24 weeks did not improve desensitization to peanut exposure after food challenge.

Dietary fiber pectin alters the gut microbiota and diminishes the inflammatory immune responses in an experimental peach allergy mouse model

Since therapeutic options are limited the utilization of prebiotics is suggested to prevent food allergies (FAs). Using an experimental peach allergy model we explored the effect of dietary fiber pectin, a high-methoxyl heteropolysaccharide, on the manifestation of FA. CBA/J mice were sensitized, subsequently orally boosted and provoked with peach peel extract. For dietary intervention, mice were fed a pectin containing diet before (primary-preventive) or after (secondary-preventive) sensitization. Non-treated allergic and sham-treated mice were fed a diet containing 20% cellulose. Fecal microbiota, humoral and intestinal immune cell responses were analyzed. Pectin remarkably affected the gut microbiota composition and diversity, promoting mainly the growth of Bacteroides. The frequency of mast cells, macrophages, and CD3+T cells in the lamina propria of the small intestine was reduced, whereas the frequency of B cells and CD4+T cell subpopulation was enhanced. Pectin intervention in the primary-preventive stetting significantly triggered serum IgA levels, whereas production of IgE and mMCPT-1 was reduced. Remarkably, in both settings peach allergen-specific IgG1/IgG2a ratio and specific IgE were significantly reduced to baseline. The data suggest, that dietary supplementation of pectin in both intervention approaches can diminish inflammatory responses and signs of allergic immune responses, accompanied by alteration of the gut microbiota composition.

Applications of basophil activation test in paediatric allergic diseases

Basophilic granulocytes, containing and releasing histamine after a specific allergy stimulation, are directly involved in IgE-mediated allergic reactions. CD63 is a transmembrane protein of secretory lysosomes of basophils and its upregulation is related with the release of histamine to the extracellular space during IgE-mediated allergic reactions. Basophil activation test (BAT) measures the activation of circulating basophils upon the in vitro stimulation of living blood cells with specific allergens. Such a test is particularly safe and reproducible and has recently emerged as a new promising diagnostic tool for allergic diseases. BAT can be used to diagnose food allergy and represents a promising alternative to oral food challenge tests, especially in children as it is less invasive, safer, and cheaper than the gold standard tests. As a biomarker of tolerance and reactivity, it is also useful to monitor natural resolution and clinical response to immune-modulatory treatments. Regarding drug allergies, BAT is even the only possible applicable diagnostic tool for allergy reactions to some drugs, because of the lack of alternative test, or given that those commonly used are unreliable, or equivocal. Additionally, BAT allows to screen patients with more active urticarial and identify Hymenoptera-allergic patients with negative venom-specific immunoglobulin (Ig)E. In respiratory allergic diseases, BAT can facilitate the diagnosis of local allergic rhinitis and evaluate basophil allergen sensitivity in allergic asthma. Although IgE-sensitization in allergic asthma is usually demonstrated by skin prick test and specific IgE, those tests do not predict the clinical allergy contribution to asthma pathogenesis. To date, the potential of BAT in the diagnostic work-up of allergic diseases is well established, but a better standardization of its use is needed. This narrative review summarizes the state-of-the-art BAT technology and applications in pediatric allergic diseases, focusing on immune-related mechanisms and the BAT real clinical utility.

Probiotics as adjuvants to mitigate adverse reactions and enhance effectiveness in Food Allergy Immunotherapy

In the past decades, food allergies became increasingly dominant since early childhood, leading to a lower quality of life and to increasing costs addressed by the health care system. Beside standard avoidance of specific allergens and drug treatments following allergen exposure, a great deal of research has lately focused on Food Allergy Allergen Immunotherapy (FA-AIT). SCIT and EPIT (Subcutaneous and Epicutaneous Immunotherapy), OIT (Oral Immunotherapy), and SLIT (Sublingual Immunotherapy) consist in gradual exposure to allergens to desensitize and achieve tolerance once therapy has ended. Although promising, FA-AIT may bring acute local and systemic adverse reactions. To enhance efficacy, safety and convenience of AIT, the quest of potential adjuvants to mitigate the adverse reactions becomes crucial. Immunomodulatory activities, such as that of increasing the regulatory T cells and decreasing the IgE, have been observed in specific probiotics' strains and multiple studies elucidated the role of gut microbiota as a major interplayer among the host and its immune system. In this review, the microbiome modulation is shown as potential AIT adjuvant, nevertheless the need of more clinical studies in the near future is pivotal to assess the efficacy of targeted bacterial therapies and faecal microbiota transplantation.

The role of intestinal bacteria in promoting tolerance to food

The global prevalence of atopic diseases, including food allergy, is increasing and correlates with shifts in the commensal microbiota triggered by modern lifestyle factors. Current research focuses on the immunological mechanisms and microbial cues that regulate mucosal immunity and prevent allergic responses to food. We review the identification and characterization of novel antigen-presenting cell subsets that may be critical for the establishment and maintenance of tolerance to both food and intestinal bacteria. Microbially derived products, particularly from the Lachnospiraceae family of Clostridia, regulate intestinal homeostasis through a variety of mechanisms. Here, we highlight recent work on Clostridial metabolites and products that mediate protection against allergic responses to food.

Zéro allergie research clinic: a clinical and research initiative in oral immunotherapy for managing IgE-mediated food allergy

BACKGROUND AND METHODS

The Zéro allergie research clinic (Saguenay, Canada) is a clinical and research initiative in oral immunotherapy (OIT) for managing IgE-mediated food allergy (FA). A total of 183 children with FA and 27 non-allergic siblings were recruited to date in the Zéro allergie cohort (ZAC) to better understand biological mechanisms underlying FA and OIT prognosis. The primary aims are to (a) better understand the genetic, epigenetic, transcriptomic, metabolomic, and microbial diversity associated with FA; (b) establish the multi-omics and microbial diversity profiles of children following OIT to identify predictive prognosis biomarkers, (c) make OIT more accessible to the population of the Saguenay-Lac-Saint-Jean region, and (d) build a biobank of data and biological material.

RESULTS

The ZAC constitutes a unique and rich biobank of biological samples (blood, buccal swabs, microbiota samples [intestinal, buccal, nasal, and cutaneous]) combined with clinical data and more than 75 phenotypic characteristics.

CONCLUSIONS

This represents an innovative interdisciplinary initiative by researchers, allergists, and paediatricians to make FA care accessible to a greater number of children with IgE-mediated FA. Ultimately, it will contribute to provide more accessible treatment options with greater chances of success through a better understanding of the biological nature of FA and OIT.

Basophil activation test in the food allergy clinic: its current use and future applications

INTRODUCTION

The basophil activation test (BAT) has shown evidence of high sensitivity and high specificity to support the diagnosis of IgE-mediated allergy. It is a functional test that uses live cells analyzed by flow cytometry and thus needs to be performed within 24h of blood collection. BAT has shown to be reproducible and reliable when tested in a clinical diagnostic laboratory with standardized protocols and flow cytometry settings.

AREAS COVERED

In this review, we summarize the evidence to support clinical use of BAT and the next steps required for clinical implementation for an improve clinical care for patients with suspected IgE-mediated food allergy.

EXPERT OPINION

BAT has recently been included in Clinical Guidelines of Food Allergy Diagnosis and its implementation in clinical practice depends largely on availability. Proposed clinical applications of the BAT include: distinction between food allergy and asymptomatic IgE sensitization; determination of food allergic status to peanut, tree nuts and seeds in polysensitized children; evaluation of tolerance to baked egg and baked milk in egg and milk allergic children; identification of patients at high-risk of severe allergic reactions; monitoring for spontaneous resolution of food allergy; confirmation of eligibility for specific treatments of food allergy; prediction and monitoring of response to immunomodulatory treatments.

Inulin-gel-based oral immunotherapy remodels the small intestinal microbiome and suppresses food allergy

Despite the potential of oral immunotherapy against food allergy, adverse reactions and loss of desensitization hinder its clinical uptake. Dysbiosis of the gut microbiota is implicated in the increasing prevalence of food allergy, which will need to be regulated to enable for an effective oral immunotherapy against food allergy. Here we report an inulin gel formulated with an allergen that normalizes the dysregulated ileal microbiota and metabolites in allergic mice, establishes allergen-specific oral tolerance and achieves robust oral immunotherapy efficacy with sustained unresponsiveness in food allergy models. These positive outcomes are associated with enhanced allergen uptake by antigen-sampling dendritic cells in the small intestine, suppressed pathogenic type 2 immune responses, increased interferon-γ+ and interleukin-10+ regulatory T cell populations, and restored ileal abundances of Eggerthellaceae and Enterorhabdus in allergic mice. Overall, our findings underscore the therapeutic potential of the engineered allergen gel as a suitable microbiome-modulating platform for food allergy and other allergic diseases.

Two-year post-treatment outcomes following peanut oral immunotherapy in the Probiotic and Peanut Oral Immunotherapy-003 Long-Term (PPOIT-003LT) study

BACKGROUND

Few studies have examined long-term outcomes following oral immunotherapy (OIT); none have examined long-term risks and benefits associated with distinct clinical outcomes (desensitization, remission).

METHODS

Participants completing the probiotic and peanut oral immunotherapy (PPOIT) -003 randomized trial were enrolled in a follow-on study, PPOIT-003LT. Peanut ingestion, reactions, and health-related quality of life (HRQOL) were monitored prospectively. Outcomes at 1-year and 2-years post-treatment were examined by treatment group and by post-OIT clinical outcome (remission, desensitization without remission [DWR], allergic).

RESULTS

86% (151/176) of eligible children enrolled. Post-treatment peanut ingestion at 2-years post-treatment were similar for PPOIT (86.7%) and OIT (78.7%) groups, both higher than placebo (10.3%). Reactions reduced over time for all treatment and clinical outcome groups (PPOIT 31.7% to 23.3%, OIT 37.7% to 19.7%, placebo 13.8% to 6.9%; remission 27.5% to 15.9%; DWR 57.9% to 36.8%; allergic 11.6% to 7%). At 2-years post-treatment, similar proportions of remission and allergic participants reported reactions (RD 0.09 (95%CI -0.03, 0.20), p = .127), whereas more DWR participants reported reactions than remission (remission vs DWR: RD -0.21 (95%CI -0.39; -0.03), p = .02) and allergic (DWR vs allergic: RD 0.30 (95%CI 0.13, 0.47), p = .001) participants. At 2-years post-treatment, 0% remission versus 5.3% DWR versus 2.3% allergic participants reported adrenaline injector usage. Remission participants had significantly greater HRQOL improvement (adjusted for baseline) compared with both DWR (MD -0.54 (95%CI -0.99, -0.10), p = .017) and allergic (MD -0.82 (95%CI -1.25, -0.38), p < .001).

CONCLUSION

By 2-years post-treatment, remission participants reported fewer reactions, less severe reactions and greater HRQOL improvement compared with DWR and allergic participants, indicating that remission is the patient-preferred treatment outcome over desensitization or remaining allergic.

Clarifying the Hazy Concepts of Food Allergies and Sensitivities

Food allergies, food sensitivities, and adverse reactions to food represent common reasons for gastroenterology and allergy referral. The epidemiology of these disorders is changing; food allergies are more common than previously thought, and there is a heightened sense of awareness about food sensitivities. Symptoms do not always accurately predict the underlying pathophysiology nor distinguish the underlying etiology. This may lead to unnecessary testing, which is often unrewarding and expensive. Myths and misconceptions about food allergies and sensitivities are common and may lead to unwarranted treatment using untested therapies. Importantly, a missed diagnosis of a true food allergy can have serious consequences. This article discusses the differences between food allergies and sensitivities, including their epidemiology, underlying pathophysiology, key symptoms, and diagnostic criteria, as well as their treatment options.

The Safety and Efficacy of Baked Egg and Milk Dietary Advancement Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

Cow's milk and egg allergy affect approximately 1.9% and 0.9% of children, respectively. Dietary advancement therapies (DATs), including milk (ML) and egg (EL) ladders, and baked milk (BM-OIT) and baked egg (BE-OIT) oral immunotherapy, are potential therapeutic options for these patients.

OBJECTIVE

To perform systematic review and meta-analysis of the safety and efficacy of DATs in children with IgE-mediated milk or egg allergy.

METHODS

A systematic literature review was conducted, exploring 22 potential outcomes, with meta-analysis performed where ≥3 studies reported data. The GRADE approach was used to determine the certainty of evidence for each outcome, and the Johanna Briggs Institute tools were used for determining risk of bias.

RESULTS

Twenty-nine studies met inclusion criteria among 9946 titles screened. Tolerance occurred in 69% of EL, 58% of ML, 49% of BE-OIT, and 29% of BM-OIT patients. All-severity allergic reactions occurred in 21% of EL, 25% of ML, 20% of BE-OIT, and 61% of BM-OIT patients, with epinephrine use in 3% of EL, 2% of ML, and 9% of BM-OIT patients. At-home reactions occurred in 19% of BE-OIT and 10% of BM-OIT patients. Discontinuation occurred in 14% of EL, 17% of ML, 17% of BE-OIT, and 20% of BM-OIT patients. The mean time to BE egg and BE-OIT tolerance was 13.25 months (4 studies) and 19.1 months (3 studies). Certainty of evidence was very low, and risk of bias high. Study heterogeneity was high, attributable to multiple factors.

CONCLUSIONS

There is very low certainty of evidence supporting DAT safety and efficacy. We cannot conclude that DAT accelerates tolerance development.

Immunotherapy and biologics in the management of IgE-mediated food allergy: Systematic review and meta-analyses of efficacy and safety

Food allergy (FA) is a potentially life-threatening chronic condition that is becoming an increasing public health problem worldwide. This systematic review (SR) was carried out to inform the development of clinical recommendations on the treatment of IgE-mediated FA with biologics and/or IT for the update of the EAACI guidelines. A SR of randomized-controlled trials or quasi-controlled trials was carried out. Studies were identified via comprehensive search strategies in Medline, Embase, and Cochrane Library, up to April 2022.

POPULATION

Human adults, children, and adolescents with IgE-mediated FA.

INTERVENTION

IT and/or biologics.

COMPARATOR

Placebo or standard-of-care (allergen avoidance).

OUTCOME

Efficacy (desensitization, sustained unresponsiveness (SU), remission), quality of life, and safety (systemic and local adverse reactions (AR)). The Cochrane RoB tool was used to assess the risk of bias. It was reported according to PRISMA and registered in PROSPERO CRD4202229828. After screening, 121 studies were included (111 for IT and 10 for biologics). Most studies had a high risk of bias and showed high heterogeneity in design and results. Metanalysis showed a positive effect of biologics and IT in terms of relative risk (RR) for achieving tolerance to the culprit food compared to avoidance or placebo. Omalizumab for any FA showed a RR of 2.17 [95% confidence interval: 1.22, 3.85]. For peanut allergy, oral IT (OIT) had a RR of 11.94 [1.76, 80.84] versus avoidance or placebo, sublingual IT (SLIT) had a RR of 3.00 [1.04, 8.66], and epicutaneous IT (EPIT) of 2.16 [1.56, 3.00]. OIT had a RR of 5.88 [2.27, 15.18] for cow's milk allergy, and of 3.43 [2.24, 5.27] for egg allergy. There was insufficient data on SLIT or EPIT for the treatment of egg and milk allergies. Most ARs reported were mild. For OIT the most common AR involved the gastrointestinal system and for EPIT, AR's most commonly affected the skin. There was limited data on severe or life-threatening ARs. There was limited evidence for long term efficacy and quality of life. In conclusion, biologics and IT, alone or in combination, are effective in achieving desensitization while on active treatment but more evidence is needed on long-term tolerance as current evidence is not of high quality. Adverse events while on therapy are generally mild to moderate but a long-term comprehensive safety profile is missing. There is a critical need to optimize and standardize desensitization protocols and outcome measures to facilitate our understanding of the efficacy and safety as well as to allow for comparison between interventions.

Oral Immunotherapy: An Overview

Oral immunotherapy (OIT) is an alternative treatment of IgE-mediated food allergy that has been shown to increase tolerance threshold to many of the top food allergens, although this effect may be dependent on age, dose, frequency, and duration. OIT has been shown to be effective and safe in infants, and early initiation can improve rates of desensitization even for those foods whose natural history favors loss of allergy. Studies looking at protocol modification to improve OIT success are ongoing as is the evaluation of clinical tools to help monitor OIT effects.

Omalizumab for the reduction of allergic reactions to foods: a narrative review

The frequency of food allergies varies between 2% and 10%, depending on characteristics including age, region, race, and method of diagnosis self-reported by patients or oral food challenges (OFCs). The most common allergies reported are tree nuts (1.2%), milk (1.9%), peanuts (2.2%), and shellfish (1.3%). Omalizumab injection has now been approved by the FDA for the treatment of immunoglobulin E-mediated food allergies in specific adults and children aged one year or older. This medication reduces the risk of allergic reactions (Type I), which can include anaphylaxis, when an individual accidentally encounters one or more food allergens. Omalizumab functions by binding to IgE and altering IgE-mediated pathways, which lessens IgE's capacity to cause allergic reactions. Promising outcomes from clinical trials and case studies include lowered anaphylactic risk and enhanced tolerance to allergens. Omalizumab, however, may have adverse effects; thus, close observation is required. Overall, this review sheds light on the efficacy, safety, and clinical implications of omalizumab, highlighting its potential as a useful intervention for IgE-mediated food allergies.

Peanut oral immunotherapy using an extensively heated and baked novel composition of peanuts

BACKGROUND

Oral immunotherapy (OIT) is an increasingly acceptable therapeutic option for peanut-allergic (PA) children, despite significant side effects. Major peanut allergenic proteins are heat-resistant and are not rendered hypoallergenic after baking or cooking. Lyophilized peanut protein-MH (LPP-MH) is a novel composition from developing peanuts, enabling cooking-induced reduction in allergenicity. We aimed to explore the safety and efficacy of OIT, with extensively heated and baked (EHEB) LPP-MH in PA children.

METHODS

In a single-arm, single-center, pilot study, PA children with a single highest tolerated dose of <100 mg peanut protein were placed on a 40-week OIT protocol with 300 mg daily of heat-treated LPP-MH. A repeat open peanut food challenge was performed after 40 weeks of treatment and at a 6-12 months of follow-up visit.

RESULTS

Thirty-three children with PA were enrolled, with a mean cumulative tolerated dose (MCTD) of 71.2 mg PP (95% CI 45-100 mg). After 40 weeks, 32/33 patients were able to consume more than 300 mg of natural PP, with MCTD of 1709 mg (CI 365-3675 mg). There were no severe allergic reactions requiring epinephrine, during any of the observed LPP-MH challenges or any treatment related doses at home. After 6-12 months on daily maintenance, the MCTD was 8821 mg (95% CI 1930-13,500 mg). This enabled most children age-appropriate dietary inclusion of peanuts.

CONCLUSION

An OIT protocol with heat-treated LPP-MH, a novel composition from developing peanuts, seems a potentially safe and efficacious OIT modality for PA children, enabling the introduction of dietary levels of peanut proteins in highly allergic PA children. Validation in randomized controlled studies is mandated.

The Future of Food Allergy Management: Advancements in Therapies

PURPOSE OF REVIEW

To review current and future treatment options for IgE-mediated food allergy.

RECENT FINDINGS

Recent years have seen major developments in both allergen-specific and allergen-non-specific treatment options, with the first FDA-approved peanut oral immunotherapy (OIT) product becoming available in 2020. In addition to OIT, other immunotherapy modalities, biologics, adjunct therapies, and novel therapeutics are under investigation. Food allergy is a potentially life-threatening condition associated with a significant psychosocial impact. Numerous products and protocols are under investigation, with most studies focusing on OIT. A high rate of adverse events, need for frequent office visits, and cost remain challenges with OIT. Further work is needed to unify outcome measures, develop treatment protocols that minimize adverse events, establish demographic and clinical factors that influence candidate selection, and identify patient priorities.

Evaluation of clinical outcomes of efficacy in food allergen immunotherapy trials, COFAITH EAACI task force

Food allergy is a global public health problem that until recent years lacked any aetiological treatment supported by academy, industry and regulators. Food immunotherapy (AIT) is an evolving treatment option, supported by clinical practice and industry trial data. Recent AIT meta-analyses have highlighted the difficulty in pooling safety and efficacy data from AIT trials, due to secondary heterogeneity in the study. An EAACI task force (CO-FAITH) initiated by the Paediatric Section was created to focus on AIT efficacy outcomes for milk, egg and peanut allergy rather than in trial results. A systematic search and a narrative review of AIT controlled clinical trials and large case series was conducted. A total of 63 manuscripts met inclusion criteria, corresponding to 23, 21 and 22 studies of milk, egg and peanut AIT, respectively. The most common AIT efficacy outcome was desensitization, mostly defined as tolerating a maintenance phase dose, or reaching a particular dose upon successful exit oral food challenge (OFC). However, a large degree of heterogeneity was identified regarding the dose quantity defining this outcome. Sustained unresponsiveness and patient-reported outcomes (e.g. quality of life) were explored less frequently, and to date have been most rigorously described for peanut AIT versus other allergens. Change in allergen threshold assessed by OFC remains the most common efficacy measure, but OFC methods suffer from heterogeneity and methodological disparity. This review has identified multiple heterogeneous outcomes related to measuring the efficacy of AIT. Efforts to better standardize and harmonize which outcomes, and how to measure them must be carried out to help in the clinical development of safe and efficacious food allergy treatments.

A Review of Shared Decision-Making, Published Protocols, and Post-desensitization Strategies in Oral Immunotherapy (OIT)

PURPOSE OF REVIEW

The aim of this review is to highlight key published oral immunotherapy (OIT) protocols and post-desensitization strategies for the major food allergens and to cover important concepts to consider when evaluating OIT for food-allergic patients. Shared decision-making should help identify patient and family values which will help influence the type of evidence-based protocol and maintenance strategy to use.

RECENT FINDINGS

With food OIT emerging as a treatment option, there is a pressing need for patients, physicians, and other providers to have a nuanced understanding of the management choices available to them. There are now randomized controlled trials (RCT) of OIT for peanut, egg, milk, and wheat, and reports of cohorts of patients who have undergone OIT for tree nuts and sesame clinically. The current published protocols contain significant diversity in terms of starting dose, build-up schedule, maintenance dose, and even the product used for desensitization. Emerging data can help direct the long-term maintenance strategy for patients on OIT. Based on patient and family values elicited through the shared decision-making process, an OIT protocol may be selected that balances the level of desensitization, potential side effects, frequency of clinic visits, and potential to induce sustained unresponsiveness, among other factors. Once maintenance dosing is reached, most patients will need to maintain regular exposure to the food allergen to remain desensitized. The option to transition to commercial food products with equivalent amounts of food protein as the OIT maintenance dose would simplify the dosing process and perhaps improve palatability as well. Less frequent or decreased OIT dosing can provide practical benefits but may affect the level of desensitization and safety for some patients.

Updated grading system for systemic allergic reactions: Joint Statement of the World Allergy Organization Anaphylaxis Committee and Allergen Immunotherapy Committee

There is a lack of consensus over the description and severity assignment of allergic adverse reactions to immunotherapy, although there seems to be a consensus at least in terms of using the World Allergy Organization (WAO) grading systems to describe local adverse events for Sublingual Immunotherapy (SLIT) and Systemic Allergic Reactions (SARs) to Subcutaneous Immunotherapy (SCIT) amongst the major national/regional allergy societies. In this manuscript, we propose a modification of the previous WAO Grading system for SARs, which aligns with the newly-proposed Consortium for Food Allergy Research (CoFAR) Grading Scale for Systemic Allergic Reactions in Food Allergy (version 3.0). We hope this can facilitate a unified grading system appropriate to SARs due to allergen immunotherapy, independent of allergen and route of administration, and across clinical and research practice.

New Approaches to Food Allergy Immunotherapy

Food allergy is an increasing public health problem in children and adults. In addition to the risk of potentially severe reactions, food allergy can have a significant burden on quality of life, nutrition, cost of living, and social activities. Traditionally, treatment has primarily included strict food allergen avoidance and use of emergency medications to treat an allergic reaction. However, in recent years, there have been significant strides in the advancement of food allergy treatment, including the approval of the first and only approved therapy (peanut oral immunotherapy) for food allergy in 2020. Clinical trials have primarily focused on food allergen immunotherapy (oral, epicutaneous, sublingual). Building off of a foundation of promising data supporting the efficacy of food oral immunotherapy and our greater understanding of the underlying mechanism of immunotherapy, newer approaches, including alternative routes of delivery, adjuncts to therapy, modified allergens, and utilization in younger patients, aim to provide safer and more effective treatment approaches to the millions of patients burdened by food allergy.

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.

Efficacy of biological agents combined with oral immunotherapy (OIT) for food allergy: a protocol for a systematic review and meta-analysis

INTRODUCTION

Food allergy affects a large population throughout the world. Recently, oral immunotherapy (OIT) has been reported as an effective treatment for severe food allergy. Although OIT was successful in numerous trials in desensitisation, adverse events including anaphylaxis during OIT frequently occur. Additionally, some patients fail to be desensitised after OIT and the response to treatment is often not sustained. As a further adjunctive therapy to facilitate OIT, the role of biological agents has been identified. For example, efficacy and safety of omalizumab as an adjuvant therapy of OIT has become apparent through some RCTs and observational studies. Interest towards this topic is growing worldwide, and ongoing trials will provide additional data on the biologics in food allergy.We aim to systematically analyse the efficacy and safety of OIT combined with biological agents for food allergy.

METHODS AND ANALYSIS

This paper provides a protocol for a systematic review of the relevant published analytical studies using an aggregate approach following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines. Two authors will perform a comprehensive search for studies on MEDLINE/PubMed, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) databases. Subsequently, two independent authors will perform abstract screening, full-text screening and data extraction. A meta-analysis will be conducted as appropriate.

ETHICS AND DISSEMINATION

The protocol of this systematic review will be provided in a peer-reviewed journal. As the researchers will not identify the individual patients included in the studies, they do not need to acquire ethics approval.

PROSPERO REGISTRATION NUMBER

CRD42022373015.

Food Allergen Immunotherapy in the Treatment of Patients with IgE-Mediated Food Allergy

The prevalence of allergic diseases, including food allergy, is increasing, especially in developed countries. Implementation of an elimination diet is not a sufficient therapeutic strategy in patients with food allergy, whose quality of life is significantly impaired. In recent years, new effective therapeutic strategies have been developed, such as the application of oral, sublingual, and epicutaneous immunotherapy. Oral immunotherapy is the most often applied strategy because of its effectiveness and ease of application, with an acceptable safety profile. The effectiveness of oral immunotherapy in patients with egg, cow's milk, and peanut allergy has been proven both in terms of raising of the threshold and the development of tolerance, and in some patients, the development of sustainable unresponsiveness. Although oral immunotherapy is an effective treatment for food allergy, several limitations, including a long duration and a significant rate of reported adverse events, reduces its success. Therefore, new therapeutic options, such as treatment with biologicals, either as combinations with food allergen immunotherapy or as monotherapy with the aim of improving the efficacy and safety of treatment, are being investigated.

Clinical outcome and component-specific antibody levels in egg allergic children after lightened oral immunotherapy

OBJECTIVE

To evaluate the clinical outcome of lightened version of egg oral immunotherapy (OIT) and to analyze egg allergen component-specific antibody levels during short up-dosing with egg white powder and maintenance by egg in daily diet.

PATIENTS AND METHODS

Eighteen egg-allergic children received egg powder with short up--dosing and they maintained tolerance using egg in daily diet. Seventeen egg-allergic children served as a control group. Component-resolved analysis of serum immunoglobulin E (IgE), IgA1, IgA2, and IgG4 levels were determined at inclusion, after up-dosing and after 1 year of immunotherapy. Skin-prick tests were performed at inclusion and after 1 year of therapy.

RESULTS

All 18 patients in the egg OIT group were successfully desensitized. Desensitization was achieved on average in 4.5 months. In the control group, only two children tolerated egg in oral food challenge after 1 year. Of the measured immune markers, smaller wheal diameters in skin-prick testing, reduction in component-specific IgE levels, and increase in component-specific IgA1, IgA2, and IgG4 levels were associated with desensitization.

CONCLUSION

A lightened egg OIT is effective and safe in children with egg allergy. Increase in all egg component-specific IgA1, IgA2 and IgG4 levels and decrease in all egg component--specific IgE levels were observed after 12 months of OIT.

Exploratory immunogenicity outcomes of peanut oral immunotherapy: Findings from the PALISADE trial

BACKGROUND

Immunoglobulin E (IgE) and immunoglobulin G4 (IgG4) to peanut and its components may influence the clinical reactivity to peanut. Allergen-specific immunotherapy is known for modifying both IgE and IgG4. Peanut oral immunotherapy may influence these serological parameters.

METHODS

Exploratory analyses of serological data from participants receiving peanut (Arachis hypogaea) allergen powder-dnfp (PTAH) and placebo in the double-blind, randomized, phase 3 PALISADE trial were conducted to evaluate potential relationships between peanut-specific and peanut component-specific (Ara h 1, Ara h 2, Ara h 3, Ara h 6, Ara h 8, and Ara h 9) IgE and IgG4 levels and clinical outcomes.

RESULTS

A total of 269 participants (PTAH, n = 202; placebo, n = 67) were analyzed. No relationship was observed between specific IgE and IgG4 levels at screening and maximum tolerated peanut protein dose during screening or response status during exit double-blind placebo-controlled food challenge (DBPCFC). In PTAH-treated participants, no relationship was observed between IgE and IgG4 levels at screening and maximum symptom severity during exit DBPCFC. Postscreening ratios (ie, postscreening/screening) in the PTAH group were significant at the end of updosing and exit visit for most components. Postscreening changes in specific IgE levels were more pronounced with PTAH versus placebo for most components.

CONCLUSIONS

Specific IgE and IgG4 levels at screening are not correlated with screening or exit DBPCFC results, and are not predictive of clinical response to PTAH. Peanut (Arachis hypogaea) allergen powder-dnfp contains the relevant and immunodominant allergens, inducing immunological changes with the treatment.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02635776.

Gut microbiota and fecal metabolites in sustained unresponsiveness by oral immunotherapy in school-age children with cow's milk allergy

BACKGROUND

Oral immunotherapy (OIT) can ameliorate cow's milk allergy (CMA); however, the achievement of sustained unresponsiveness (SU) is challenging. Regarding the pathogenesis of CMA, recent studies have shown the importance of gut microbiota (Mb) and fecal water-soluble metabolites (WSMs), which prompted us to determine the change in clinical and gut environmental factors important for acquiring SU after OIT for CMA.

METHODS

We conducted an ancillary cohort study of a multicenter randomized, parallel-group, delayed-start design study on 32 school-age children with IgE-mediated CMA who underwent OIT for 13 months. We defined SU as the ability to consume cow's milk exceeding the target dose in a double-blind placebo-controlled food challenge after OIT followed by a 2-week-avoidance. We longitudinally collected 175 fecal specimens and clustered the microbiome and metabolome data into 29 Mb- and 12 WSM-modules.

RESULTS

During OIT, immunological factors improved in all participants. However, of the 32 participants, 4 withdrew because of adverse events, and only 7 were judged SU. Gut environmental factors shifted during OIT, but only in the beginning, and returned to the baseline at the end. Of these factors, milk- and casein-specific IgE and the Bifidobacterium-dominant module were associated with SU (milk- and casein-specific IgE; OR for 10 kUA/L increments, 0.67 and 0.66; 95%CI, 0.41-0.93 and 0.42-0.90; Bifidobacterium-dominant module; OR for 0.01 increments, 1.40; 95%CI, 1.10-2.03), and these associations were observed until the end of OIT.

CONCLUSIONS

In this study, we identified the clinical and gut environmental factors associated with SU acquisition in CM-OIT.

[Treatment for living with food allergy]

The treatment of food allergy involves completely removing the allergenic food from the diet, careful label reading, and ingredient awareness. Family education is crucial, understanding alternative names for the allergen. An emergency action plan provided by the doctor, with clear instructions for epinephrine application and when to seek medical attention, is essential. For mild to moderate symptoms, oral antihistamines may be prescribed. Psychological support is necessary due to emotional repercussions. Collaboration with an allergy specialist is crucial for personalized treatment. Natural tolerance to the food may be achieved, especially in non-IgE-mediated allergies. However, some allergic manifestations persist, requiring treatment alternatives. Avoidance of the allergen and epinephrine application are key measures. Immunotherapy aims to desensitize immune cells, but its effectiveness varies. Bioterapeutic agents, such as monoclonal antibodies, are under investigation, although their clinical use still requires more studies.

[Food desensitization]

In recent times, the primary approach to treating food allergies involved strict avoidance of the triggering allergen. Many considered this approach as lacking true treatment, leaving patients vulnerable to even small amounts or hidden sources of the allergenic food. Desensitization or Oral Tolerance Induction (OTI) is a studied method aiming for a lasting tolerance to the allergen. The ultimate goal is permanent tolerance, where allergic reactions won't reoccur after new exposure to the triggering allergen, following a period of abstinence. The research mainly focuses on allergen-specific immunotherapy, covering three routes: oral, sublingual, and epicutaneous immunotherapy. Milk, egg, and peanuts are the extensively studied foods due to their prevalence in allergies. The oral route is favored for inducing tolerance because ingestion of a food antigen by a non-allergic individual triggers an active immune response without causing an allergic reaction. The paradigm has shifted from recommending avoidance to early consumption strategies to prevent allergies. The period from 4 to 6 months of age is considered immunologically sensitive, where children with risk factors show increased allergic sensitization risk. Implementing these recommendations, considering family and community preferences, may reduce the burden of food allergies and healthcare costs.

United States Drug Allergy Registry (USDAR) grading scale for immediate drug reactions

BACKGROUND

There is no accepted grading system classifying the severity of immediate reactions to drugs.

OBJECTIVE

The purpose of this article is to present a proposed grading system developed through the consensus of drug allergy experts from the United States Drug Allergy Registry (USDAR) Consortium.

METHODS

The USDAR investigators sought to develop a consensus severity grading system for immediate drug reactions that is applicable to clinical care and research.

RESULTS

The USDAR grading scale scores severity levels on a scale of 0 to 4. A grade of no reaction (NR) is used for patients who undergo challenge without any symptoms or signs, and it would confirm a negative challenge result. A grade 0 reaction is indicative of primarily subjective complaints that are commonly seen with both historical drug reactions and during drug challenges, and it would suggest a low likelihood of a true drug allergic reaction. Grades 1 to 4 meet the criteria for a positive challenge result and may be considered indicative of a drug allergy. Grade 1 reactions are suggestive of a potential immediate drug reaction with mild symptoms. Grade 2 reactions are more likely to be immediate drug reactions of moderate severity. Grade 3 reactions have features suggestive of a severe allergic reaction, whereas grade 4 reactions are life-threatening reactions such as anaphylactic shock and fatal anaphylaxis.

CONCLUSION

This proposed grading schema for immediate drug reactions improves on prior schemata by being developed specifically for immediate drug reactions and being easy to implement in clinical and research practice.

Updates in food allergen immunotherapy

PURPOSE OF REVIEW

Food allergies are on the rise. Though allergen avoidance and management of acute reactions have been the backbone of therapy, complete avoidance and timely acute care is often not feasible. Food allergen immunotherapy (FAIT) is a novel and evolving treatment option intended to induce desensitization and potential sustained unresponsiveness (SU) to food allergens. This review addresses the methods, mechanisms, efficacy, and adverse effects of oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) for food allergens in the published literature.

RECENT FINDINGS

Single FAIT has been most extensively studied in peanut, milk, and hen's egg allergic patients and has been successful in achieving desensitization in treated individuals through various modalities. Long-term data regarding SU is limited; however, current data suggests subsets of patients may be more likely to achieve SU compared to others. Other studies are actively assessing multifood AIT and novel FAIT protocols with adjunctive therapies.

SUMMARY

Food allergy constitutes a prevalent problem with far-reaching consequences. The emergence of FAIT may mitigate the burden of food allergy. Current evidence is promising for specific allergens and pediatric patient populations. Future studies are needed to further assess efficacy between different modalities of immunotherapy for food allergens across an age continuum.

Tolerance to heated egg in egg allergy: Explanations and implications for prevention and treatment

Hen's egg allergy is the second most frequent food allergy found in children. Allergic symptoms can be caused by raw or heated egg, but a majority of egg-allergic children can tolerate hard-boiled or baked egg. Understanding the reasons for the tolerance towards heated egg provides clues about the molecular mechanisms involved in egg allergy, and the differential allergenicity of heated and baked egg might be exploited to prevent or treat egg allergy. In this review, we therefore discuss (i) why some patients are able to tolerate heated egg; by highlighting the structural changes of egg white (EW) proteins upon heating and their impact on immunoreactivity, as well as patient characteristics, and (ii) to what extent heated or baked EW might be useful for primary prevention strategies or oral immunotherapy. We describe that the level of immunoreactivity towards EW helps to discriminate patients tolerant or reactive to heated or baked egg. Furthermore, the use of heated or baked egg seems effective in primary prevention strategies and might limit adverse reactions. Oral immunotherapy is a promising treatment strategy, but it can sometimes cause significant adverse events. The use of heated or baked egg might limit these, but current literature is insufficient to conclude about its efficacy.

Immunoglobulin G4 in eosinophilic esophagitis: Immune complex formation and correlation with disease activity

BACKGROUND

Recent studies have shown deposition of immunoglobulin G4 (IgG4) and food proteins in the esophageal mucosa of eosinophilic esophagitis (EoE) patients. Our aims were to assess whether co-localization of IgG4 and major cow's milk proteins (CMPs) was associated with EoE disease activity and to investigate the proteins enriched in proximity to IgG4 deposits.

METHODS

This study included adult subjects with EoE (n = 13) and non-EoE controls (n = 5). Esophageal biopsies were immunofluorescence stained for IgG4 and CMPs. Co-localization in paired samples from active disease and remission was assessed and compared to controls. The proteome surrounding IgG4 deposits was evaluated by the novel technique, AutoSTOMP. IgG4-food protein interactions were confirmed with co-immunoprecipitation and mass spectrometry.

RESULTS

IgG4-CMP co-localization was higher in the active EoE group compared to paired remission samples (Bos d 4, p = .02; Bos d 5, p = .002; Bos d 8, p = .002). Co-localization was also significantly higher in the active EoE group compared to non-EoE controls (Bos d 4, p = .0013; Bos d 5, p = .0007; Bos d 8, p = .0013). AutoSTOMP identified eosinophil-derived proteins (PRG 2 and 3, EPX, RNASE3) and calpain-14 in IgG4-enriched areas. Co-immunoprecipitation and mass spectrometry confirmed IgG4 binding to multiple food allergens.

CONCLUSION

These findings further contribute to the understanding of the interaction of IgG4 with food antigens as it relates to EoE disease activity. These data strongly suggest the immune complex formation of IgG4 and major cow's milk proteins. These immune complexes may have a potential role in the pathophysiology of EoE by contributing to eosinophil activation and disease progression.

Oral Immunotherapy for Peanut Allergy in Children 1 to Less Than 4 Years of Age

BACKGROUND: Peanut allergy is a common childhood allergy, and the only approved treatment for children 4 to 17 years of age is peanut allergen powder-dnfp (PTAH) oral immunotherapy. METHODS: For this phase 3, randomized, double-blind, placebo-controlled trial, we enrolled peanut-allergic children 1 to <4 years of age who experienced dose-limiting symptoms from ≤300 mg peanut protein during a screening double-blind, placebo-controlled food challenge (DBPCFC). Participants received PTAH or placebo, randomized in a 2:1 ratio, for approximately 12 months. At the trial conclusion, all participants underwent an exit BDPCFC. The primary end point was desensitization (i.e., tolerating a ≥600-mg single dose of peanut protein with only mild allergy symptoms). RESULTS: In the PTAH-treated group (n=98), 73.5% of participants tolerated a single dose of ≥600 mg peanut protein at exit DBPCFC compared with 6.3% in the placebo group (n=48). Most participants experienced an adverse event (98.0% of PTAH-treated and 97.9% of placebo-treated participants), which was mild or moderate in grade for 93.2% of participants (92.9% in PTAH-treated and 93.8% in placebo-treated participants). Treatment-related adverse events, which were mild to moderate, were experienced by 75.5% of PTAH-treated and 58.3% of placebo-treated participants. Three treatment-related systemic allergic reactions, none of which were severe or serious in grade, were noted in two PTAH-treated participants (2%). CONCLUSIONS: In peanut-allergic children 1 to <4 years of age treated with PTAH for approximately 12 months, the majority tolerated all peanut protein dose levels assessed. PTAH-treated patients had more treatment-related adverse events, which were mild to moderate severity. (Funded by Aimmune Therapeutics; ClinicalTrials.gov number, NCT03736447.)

Food Immunotherapy: Dissecting Current Guidelines and Navigating the Gray Zone

Food allergy is a common, chronic disease that is burdensome for patients and families, with multiple dietary and social limitations and a significant psychological impact stemming from the fear of accidental exposures and potentially severe, life-threatening reactions. Until recently, the only management option consisted of strict food avoidance. Food allergen immunotherapy (food AIT) has emerged as an alternative, active intervention to strict food avoidance, with a multitude of research studies supporting its efficacy and good safety profile. Food AIT results in a raise of allergenic threshold, which provides several benefits to food-allergic patients, including protection from accidental exposures, potentially decreased severity of allergic reactions on unintentional exposures, and improvement in quality of life. In the last few years, multiple independent reports have been published proposing strategies to implement food oral immunotherapy in U.S. clinics, although formal guidelines are currently lacking. Because food immunotherapy is gaining traction, popularity, and interest among both patients and health care providers, many physicians look for guidance on how to implement this intervention in their daily practice. In other parts of the world, use of this treatment has prompted the development of various guidelines from allergy societies. This rostrum discusses currently available guidelines on food AIT from different areas of the world, describes and comments on their similarities and differences, and highlights unmet needs in this area of therapy.

Exercise-Induced Allergic Reactions in Children Desensitized to Hen's Eggs and Cow's Milk by Oral Immunotherapy

BACKGROUND

Exercise-induced allergic reactions on desensitization (EIARDs) after successful in-hospital rush oral immunotherapy (OIT) for wheat allergy have been reported. However, the incidence rates of EIARDs after rush OIT for egg allergy and milk allergy have not been determined.

OBJECTIVE

To determine the frequency of EIARDs and risk factors associated with rush OIT for egg and milk allergy.

METHODS

This retrospective chart review, conducted in January 2020, enrolled 64 and 43 patients who underwent rush OIT for egg and milk allergy, respectively (in 2010 to 2014). In particular, 48 and 32 desensitized patients underwent exercise-provocation tests (Ex-P) after allergen administration (4,400 mg boiled egg white and 6,600 mg cow's milk protein, respectively). The EIARDs were determined by Ex-P or a suspicious event even after passing the Ex-P. Specific IgE levels to egg white, cow's milk, ovomucoid, casein, α-lactalbumin, and β-lactoglobulin were analyzed using ImmunoCAP.

RESULTS

At least one episode of EIARD was observed in 10 and 17 patients with egg and milk allergy (21% and 53%), respectively, which persisted for more than 5 years in one patient with egg allergy (2.1%) and 11 patients with milk allergy (34.4%) as of January 2020. We could not find background differences between the EIARD-positive and EIARD-negative groups, except that the egg white-specific IgE/total IgE ratio before rush OIT was significantly higher in patients with egg allergy with EIARD than in those without it.

CONCLUSIONS

Exercise-induced allergic reactions on desensitization were more frequent and common in patients with milk allergy. Moreover, EIARDs to milk allergy were more likely to persist than those to egg allergy.

The Value of Current Laboratory Tests in Diagnosing Food, Venom, and Drug Allergies

An accurate diagnosis of IgE-mediated allergies is necessary to inform risk management for severe allergic reactions including anaphylaxis for food, venom, and drug allergies. The most widely available laboratory test for allergy is serum-specific IgE testing, which is routinely used for food allergy and insect sting allergy. Testing for specific IgE is limited by high sensitivity and low specificity, resulting in concern regarding overdiagnosis. Testing of allergen components has led to improved diagnosis for some food and venom allergens. Additional options for laboratory tests, such as epitope analysis, basophil activation, and mast cell activation, are being investigated for their potential to optimize diagnosis and provide predictors for reaction severity and treatment response. In contrast, laboratory testing for drug allergy is more limited because to date, there are no well-validated commercial assays in the United States. Furthermore, it is important to diagnose delayed reactions to medications, because these also significantly affect decision-making regarding therapeutic options for infectious disorders. Reliable tests for both immediate and delayed drug hypersensitivity are much needed, because drug allergy labels can significantly limit treatment options for patients. Research in this area is emerging.