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

Role of biologics in severe food allergy

PURPOSE OF REVIEW

This review examine the dynamic landscape of food allergy treatment within the context of emerging biologics. Our purpose is to comprehensively evaluate the potential benefits, challenges, and transformative impact associated with the utilization of biologics in comparison to conventional therapeutic modalities.

RECENT FINDINGS

This document synthesizes recent scientific investigations to various biologics, such as omalizumab, ligelizumab, dupilumab, and tezepelumab, providing a nuanced understanding of their roles in oral immunotherapy, rapid desensitization, and overall food allergy management. Recent studies and clinical trials highlight the impact of anti-IgE treatment on food allergies, revealing critical findings such as dose-related efficacy, facilitation of rapid desensitization in peanut allergies, and the sustained positive outcomes observed in individuals with multifood allergies.

SUMMARY

The use of biologics presents a groundbreaking approach in the treatment of food allergies. The multifaceted action of these agents, along with their potential to overcome the challenges associated with traditional therapies, marks a significant advancement. Despite the persisting challenges of economic constraints and the need for further safety studies, biologics offer a promising avenue for improving the quality of life for individuals with food allergies. Ongoing research and collaborative efforts are imperative to fully realize the transformative potential inherent in these emerging therapeutic frontiers.

Perspectives in precautionary allergen labelling of prepackaged foods after the FAO/WHO consultation

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the perspectives regarding precautionary allergen labelling (PAL) of prepackaged foods following the consultation conducted by the Food and Agriculture Organization (FAO) and the WHO.

RECENT FINDINGS

The FAO/WHO consultation provided a comprehensive assessment of the current status and practices of PAL implementation worldwide. One of the key findings highlighted by the Expert Committee was the need for improvement in existing PAL systems. It was noted that many countries lacked uniformity in PAL practices, leading to inconsistencies in labelling and potentially misleading information for consumers. Furthermore, the consultation emphasized the importance of PAL being risk-based, taking into account both the amount and frequency of unintended allergen presence (UAP) in food products.

SUMMARY

The FAO/WHO consultation shed light on various perspectives and challenges associated with PAL of prepackaged foods. Key findings emphasized the need for improvement in existing PAL systems, including the adoption of a risk-based approach, standardized regulations, and enhanced transparency. Moving forward, collaborative efforts between regulatory agencies, food manufacturers, and consumer advocacy groups will be essential in developing effective PAL strategies that prioritize consumer safety and well being.

A murine model of peanut-allergic asthma

Objectives

Peanut allergy is an IgE-mediated food allergy that is associated with asthma in certain patients. With increasing prevalence, its great impact on the quality of life, and a lack of treatment options, the need for new therapy options is a given. Hence, models for research and development are required. This study aimed to establish a murine model of allergic airway inflammation induced by peanut allergens.

Methods

C3H mice were sensitised by intraperitoneal injections of peanut allergen extract and challenged by an intranasal application of the same extract. The assessment of airway inflammation involved the analysis of immune cells in the bronchoalveolar lavage fluid as measured by flow cytometry. Inflammatory reactions in the lung tissue were also studied by histology and quantitative PCR. Moreover, peanut-specific immune responses were studied after re-stimulation of spleen cells in vitro.

Results

Sensitisation led to allergen-specific IgE, IgA, and IgG1 seroconversion. Subsequent nasal exposure led to allergic airway inflammation as manifested by structural changes such as bronchial smooth muscle hypertrophy, mucus cell hyperplasia, infiltration of eosinophil cells and T cells, as well as an upregulation of genes expressing IL-4, IL-5, IL-13, and IFN-γ. Upon re-stimulation of splenocytes with peanut allergen, increased secretion of both T-helper type 2 (Th2) and Th1 cytokines was observed.

Conclusion

We successfully established a peanut-associated asthma model that exhibited many features characteristic of airway inflammation in human patients with allergic asthma. The model holds potential as a tool for investigating novel therapeutic approaches aimed at preventing the development of allergic asthma.

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.

Mobile App/Web Platform for Monitoring Food Oral Immunotherapy in Children: Longitudinal Clinical Validation Study

BACKGROUND

Milk and egg allergies significantly impact the quality of life, particularly in children. In this regard, food oral immunotherapy (OIT) has emerged as an effective treatment option; however, the occurrence of frequent adverse reactions poses a challenge, necessitating close monitoring during treatment.

OBJECTIVE

This study aims to evaluate the ability of a new mobile/web app called OITcontrol to monitor milk and egg OIT.

METHODS

Patients undergoing milk or egg OIT were recruited and divided into 2 groups: the active group used the OITcontrol app in conjunction with standard written monitoring methods, whereas the control group relied solely on written diaries. Investigators documented hospital doses, hospital reactions, and administered treatments on the website. Patients recorded their daily allergen home-dose intake, home reactions, and administered treatments using the app. The following variables were compared between both groups: number and severity of hospital and reported home reactions, patient's adhesion to the OITcontrol app or written diary or both in terms of daily home-dose intake and home reactions recording, and treatment and dose adjustment compliance at home in case of reaction.

RESULTS

Sixteen patients were assigned to be monitored using the OITcontrol app along with additional written methods (active group), while 14 patients relied solely on a written paper diary (control group). A similar distribution was observed in terms of sex, age, basal characteristics, allergen treated in OIT, premedication, and sensitization profile. Active patients reported a comparable number of hospital and home reactions compared with the control group. In terms of recording system usage, 13/16 (81%) active patients used the OITcontrol app, while 10/14 (71%) control patients relied on the written diary. Among active patients, 6/16 (38%) used both methods, and 1 active patient used only written methods. However, control patients recorded home reactions more frequently than active patients (P=.009). Among active patients, the app was the preferred method for recording reactions (59/86, 69%), compared with the written diary (15/86, 17%) or both methods (12/86, 14%; P<.001). Treatment compliance in home-recorded reactions was similar between both groups (P=.15). However, treatment indications after an adverse reaction were more frequently followed (P=.04) in reactions recorded solely in the app (36/59, 61%) than in the written diary (29/71, 41%) or both systems (4/12, 33%). Moreover, compliance with dose adjustments after a moderate-severe reaction in home-recorded reactions was higher in the active group than in the control group (P<.001). Home reactions recorded only in the app (16/19, 84%) were more likely to follow dose adjustments (P<.001) than those recorded in the written diary (3/20, 15%) or using both methods (2/3, 67%).

CONCLUSIONS

The OITcontrol app appears to be a valuable tool for monitoring OIT treatment in children with food allergies. It proves to be a suitable method for recording daily home dose intakes and reactions, and it seems to enhance adherence to treatment indications following an adverse reaction as well as compliance with dose adjustments in home reactions. However, additional studies are necessary to comprehensively grasp the benefits and limitations of using the OITcontrol app in the management of OIT.

Fatal food anaphylaxis in adults and children

Anaphylaxis is a life-threatening reaction characterized by the acute onset of symptoms involving different organ systems and requiring immediate medical intervention. The incidence of fatal food anaphylaxis is 0.03 to 0.3 million/people/year. Most fatal food-induced anaphylaxis occurs in the second and third decades of life. The identified risk factors include the delayed use of epinephrine, the presence of asthma, the use of recreational drugs (alcohol, nicotine, cannabis, etc.), and an upright position. In the United Kingdom (UK) and Canada, the reported leading causal foods are peanuts and tree nuts. In Italy, milk seems to be the most common cause of fatal anaphylaxis in children < 18 years. Fatal food anaphylaxis in Italian children and adolescents almost always occurs outside and is characterized by cardiorespiratory arrest; auto-injectable adrenaline intramuscular was available in few cases. Mortality from food anaphylaxis, especially in children, is a very rare event with stable incidence, but its risk deeply impacts the quality of life of patients with food allergy and their families. Prevention of fatal food anaphylaxis must involve patients and their families, as well as the general public, public authorities, and patients' associations.

Primary, secondary and tertiary prevention of food allergy: current practices and future directions

The incidence of food allergies has risen around the globe, and experts have been exploring methods of preventing such allergies in young children to ease the burden of disease and reduce the morbidity and mortality caused by anaphylaxis to food allergens. Such preventative measures can be categorised as primary, secondary and tertiary prevention, which are discussed in detail in this review. Primary prevention is defined as the prevention of becoming sensitised towards specific allergens. The evidence suggests that avoiding common allergenic foods during pregnancy and breastfeeding is not protective against food allergies, and guidelines recommend weaning from 4 to 6 months of age, with recent studies supporting the early introduction of peanuts at 4 months to prevent peanut allergy. Secondary prevention targets patients who are already sensitised and aims to halt the progression of sensitisation, with evidence for high rates of success and safety in trials of early introduction to milk and peanuts using oral immunotherapy in sensitised infants. Tertiary allergy prevention focuses on reducing the risk of a patient having anaphylaxis, with oral immunotherapy being the most common method of promoting tolerance in allergic children. Several studies have demonstrated successful reintroduction for milk, egg and peanut; however, no such guidelines are recommended for other foods. Finally, dietary advancement therapy in the form of milk and egg ladders has been employed as a method of primary, secondary and tertiary prevention of allergies, particularly in Ireland, the UK and Canada.

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.

How to handle off-label prescriptions of rupatadine, a second-generation antihistamine and PAF antagonist: a review

The off-label use of second-generation antihistamines, used outside of the formal indications authorized by regulatory authorities, in different age groups, doses or in special populations, is very common for many allergic, autoimmune and dermatological diseases. The off-label use of rupatadine (a second-generation antihistamine with PAF antagonist activity) in these conditions is reviewed here, including in combination with immunotherapy in the treatment of food allergy or allergic rhinitis, at high doses in chronic urticaria, and with prescriptions of less common but challenging conditions such as skin pruritus or mast cell activation disorders like mastocytosis. Rupatadine use is reviewed herein to confirm if its off-label management is supported by well-designed clinical trials or by published real-world cases. This review will contribute to increasing compliance and achieving better results in clinical practice. Off-label use of rupatadine should be left to the discretion of the prescribing healthcare professional after careful clinical evaluation.

[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.

Exploring the potential and safety of quantum dots in allergy diagnostics

Biomedical investigations in nanotherapeutics and nanomedicine have recently intensified in pursuit of new therapies with improved efficacy. Quantum dots (QDs) are promising nanomaterials that possess a wide array of advantageous properties, including electronic properties, optical properties, and engineered biocompatibility under physiological conditions. Due to these characteristics, QDs are mainly used for biomedical labeling and theranostic (therapeutic-diagnostic) agents. QDs can be functionalized with ligands to facilitate their interaction with the immune system, specific IgE, and effector cell receptors. However, undesirable side effects such as hypersensitivity and toxicity may occur, requiring further assessment. This review systematically summarizes the potential uses of QDs in the allergy field. An overview of the definition and development of QDs is provided, along with the applications of QDs in allergy studies, including the detection of allergen-specific IgE (sIgE), food allergens, and sIgE in cellular tests. The potential treatment of allergies with QDs is also described, highlighting the toxicity and biocompatibility of these nanodevices. Finally, we discuss the current findings on the immunotoxicity of QDs. Several favorable points regarding the use of QDs for allergy diagnosis and treatment are noted.

Predicting the therapeutic efficacy of AIT for asthma using clinical characteristics, serum allergen detection metrics, and machine learning techniques

Bronchial asthma is a prevalent non-communicable disease among children. The study collected clinical data from 390 children aged 4-17 years with asthma, with or without rhinitis, who received allergen immunotherapy (AIT). Combining these data, this paper proposed a predictive framework for the efficacy of mite subcutaneous immunotherapy in asthma based on machine learning techniques. Introducing the dispersed foraging strategy into the Salp Swarm Algorithm (SSA), a new improved algorithm named DFSSA is proposed. This algorithm effectively alleviates the imbalance between search speed and traversal caused by the fixed partitioning pattern in traditional SSA. Utilizing the fusion of boosting algorithm and kernel extreme learning machine, an AIT performance prediction model was established. To further investigate the effectiveness of the DFSSA-KELM model, this study conducted an auxiliary diagnostic experiment using the immunotherapy predictive medical data collected by the hospital. The findings indicate that selected indicators, such as blood basophil count, sIgE/tIgE (Der p) and sIgE/tIgE (Der f), play a crucial role in predicting treatment outcome. The classification results showed an accuracy of 87.18% and a sensitivity of 93.55%, indicating that the prediction model is an effective and accurate intelligent tool for evaluating the efficacy of AIT.

Oral immunotherapy as a curative treatment for food-allergic preschool children: Current evidence and potential underlying mechanisms

The worldwide rising prevalence of food allergy is a major public health concern. Standard care consists of allergen avoidance and rescue medication upon accidental exposure. Oral immunotherapy (OIT) is increasingly being studied as a treatment option. Although desensitization (an increased reaction threshold) is often achieved during OIT, sustained unresponsiveness (SU; clinical nonreactivity after finishing OIT) is not achieved in most patients. A few studies have investigated the effectiveness of OIT in children younger than 4 years of age (early = e-OIT) and have shown a much more favorable outcome in terms of SU development. Together with food allergy prevention studies, which have demonstrated high efficacy of early oral allergen exposure, the outcomes of e-OIT studies indicate an early-life window of opportunity to achieve SU, allowing unrestricted dietary intake. However, the underlying mechanism of the high effectiveness of e-OIT is not understood yet. Both cohort and OIT studies indicate early-life immune plasticity. An immature food-allergic response in the first years of life seems to be a major driver of this immune plasticity, along with a higher tolerogenic immunological state. Allergy maturation can likely be disrupted effectively by early intervention, preventing the development of persistent food allergy. Upcoming studies will provide important additional data on the safety, feasibility, and effectiveness of e-OIT. Combined with immune mechanistic studies, this should inform the implementation of e-OIT.

KAAACI Guidelines for Allergen Immunotherapy

Allergen immunotherapy (AIT) is a causative treatment for various allergic diseases such as allergic rhinitis, allergic asthma, and bee venom allergy that induces tolerance to offending allergens. The need for uniform practice guidelines in AIT is continuously growing because of the increasing discovery of potential candidates for AIT and evolving interest in new therapeutic approaches. This guideline is an updated version of the Korean Academy of Asthma Allergy and Clinical Immunology recommendations for AIT published in 2010. This updated guideline proposes an expert opinion by allergy, pediatrics, and otorhinolaryngology specialists with an extensive literature review. The guideline deals with basic knowledge and methodological aspects of AIT, including mechanisms, clinical efficacy, patient selection, allergens extract selection, schedule and doses, management of adverse reactions, efficacy measurements, and special consideration in pediatrics. The guidelines for sublingual immunotherapy will be covered in detail in a separate article.

Relationship between growth and food avoidance with food allergy at age 3 years: The Japan Environment and Children's Study (JECS)

Background

Basic management for food allergy (FA) is eliminating causative food from the diet, which can impact normal growth. This study examined the association between food avoidance and growth failure among children with FA aged 0-3 years using the Japan Environment and Children's Study (JECS) data.

Methods

Data on height, weight, and FA history registered were collected using self-administered questionnaires at age 1, 1.5, 2, and 3 years. A general linear model was used to examine whether dietary restriction affected body size. Height, weight, and body mass index (BMI) were adjusted for age in months using standard deviation (SD) scores for each age group by month of measurement. Presence of FA or dietary restriction was used as a binary variable.

Results

Of the 38 477 participants included in this analysis, 4070 with FAs had significantly lower SD scores for height and weight at age 3 years. With milk avoidance, significantly lower SD scores for height (male: β = -0.097 [95%CI: 0.175, -0.019], female: β = -0.103 [95%CI: 0.204, -0.002]), a significantly lower SD score for weight (male: β = -0.115[95%CI: 0.187, -0.043], female β = -0.114[95%CI: 0.203, -0.026]) were observed. Soy avoidance in males marked a lower SD score for height (β = -0.307 [95%CI: 0.474, -0.140]). Continued food avoidance until age 3 resulted in significantly lower SD score for height and weight regardless of gender.

Conclusion

Growth impairment was observed with food avoidance at age 3 years. Growth impairment were more obvious in males than in females. With regards food items, the impact of milk and soy was more significant.

A, Hussain SM, Viswanad V, Nasr MH, Sahu RK, Khan J. Modulation of immune response by nanoparticle-based immunotherapy against food allergens

The increasing prevalence of food allergies worldwide and the subsequent life-threatening anaphylactic reactions often have sparse treatment options, providing only symptomatic relief. Great strides have been made in research and in clinics in recent years to offer novel therapies for the treatment of allergic disorders. However, current allergen immunotherapy has its own shortcomings in terms of long-term efficacy and safety, due to the local side effects and the possibility of anaphylaxis. Allergen-specific immunotherapy is an established therapy in treating allergic asthma, allergic rhinitis, and allergic conjunctivitis. It acts through the downregulation of T cell, and IgE-mediated reactions, as well as desensitization, a process of food tolerance without any allergic events. This would result in a protective reaction that lasts for approximately 3 years, even after the withdrawal of therapy. Furthermore, allergen-specific immunotherapy also exploits several routes such as oral, sublingual, and epicutaneous immunotherapy. As the safety and efficacy of allergen immunotherapy are still under research, the exploration of newer routes such as intra-lymphatic immunotherapy would address unfulfilled needs. In addition, the existence of nanoparticles can be exploited immensely in allergen immunotherapy, which would lead to safer and efficacious therapy. This manuscript highlights a novel drug delivery method for allergen-specific immunotherapy that involves the administration of specific allergens to the patients in gradual increasing doses, to induce desensitization and tolerance, as well as emphasizing different routes of administration, mechanism, and the application of nanoparticles in allergen-specific immunotherapy.

Update on clinical research for food allergy treatment

The incidence of IgE-mediated food allergy (FA) has continued to increase over the years which places substantial burden on patient health and quality of life. With no cure for this disease, the mainstay of management has been allergen avoidance. However, there have been advancements in FA treatment in recent years with multiple clinical trials utilizing novel and innovative therapeutic strategies. A landmark event came in 2020 with the first drug approval for food allergy with the approval of a product for peanut oral immunotherapy. In addition to oral immunotherapy, different delivery systems of immunotherapy (SLIT, EPIT) are being studied in addition to probiotics, biologic agents - used as monotherapy and as an adjunct, and modified allergens has taken place with the hope to further enhance existing therapeutic options. The hope through these continued developments is for therapies to emerge that will provide a more comprehensive benefit to this patient population.

Biomarkers associated with persistence and severity of IgE-mediated food allergies: a systematic review

OBJECTIVE

The prevalence of food allergies (FA) has increased worldwide over the last few decades. Milk, eggs, and peanuts are among the most common allergens and can cause anaphylaxis. Therefore, we aimed to identify biomarkers that could predict the persistence and/or severity of IgE-mediated allergies to milk, eggs, and peanuts via a systematic review.

METHODS

This systematic review proceeded according to a protocol registered in the International Prospective Register of Systematic Reviews. Two independent authors extracted studies of interest from PubMed, SciELO, EMBASE, Scopus, and Ebsco databases and assessed their quality using the Newcastle-Ottawa Scale.

RESULTS

We selected 14 articles describing 1,398 patients. Among eight identified biomarkers, total IgE, specific IgE (sIgE), and IgG4 were the most often cited biomarkers of persistent allergies to milk, eggs, and peanuts. Skin prick tests, endpoint tests, and sIgE cutoff levels may predict positive responses to challenges with these foods. The basophil activation test is a biomarker for the severity and/or threshold of allergic reactions to milk and peanuts.

CONCLUSION

Only a few publications identified possible prognostic indicators of the persistence or severity of FA and outcomes of oral food challenges, indicating that more accessible biomarkers are needed to determine the likelihood of having a severe food allergic reaction.

Efficacy and safety of oral immunotherapy for peanut, cow's milk, and hen's egg allergy: A systematic review of randomized controlled trials

BACKGROUND

Oral immunotherapy (OIT) is a promising treatment for food allergies; however, safety is a concern. We synthesized evidence from the best randomized controlled trials (RCTs) on efficacy/safety of OIT for desensitization (DS) and remission (sustained unresponsiveness (SU)) in IgE mediated allergy to peanut, hen's eggs, and cow's milk. BODY: We searched Pubmed, EMBASE, and Cochrane databases (Until Oct 22) identifying 16 eligible RCTs published in English measuring food allergy by food challenge at the beginning and at the end of the study. The Cochrane Risk of Bias tool was used to assess study quality. We found 18 eligible studies. There was evidence of efficacy for DS for all allergens: peanut (RR 11.32; 95% CI 5.93, 21.60, I² 49%, 8 studies); hen's egg (RR 4.67; 2.66, 8.21, I² 0%, 5 studies); cow's milk (RR 13.98; 3.51, 55.65, I² 0%, 4 studies) and evidence for SU for peanut (RR 7.74; 2.90, 20.69, I² 0%, 3 studies) and hen's egg (RR 6.91; 1.67, 28.57, I² 0%, 2 studies). Allergic events were increased with intervention, and risk of adrenaline use increased for peanut RR 2.96; 1.63, 5.35, I² 0%, 8 studies; egg RR 1.71; 0.42, 6.92, I² 0%, 6 studies; and milk RR 8.45; 2.02, 35.27, I² 0%, 4 studies.

CONCLUSION

We found strong evidence that peanut, hen's egg, and cow's milk OIT can induce DS and some evidence for remission. There was a high risk of allergic reactions. Generalizability to the entire food allergic population is not known.

Abatacept to induce remission of peanut allergy during oral immunotherapy (ATARI): protocol for a phase 2a randomized controlled trial

Context

While oral immunotherapy (OIT) has been shown to promote the remission of mild peanut allergy in young children, there is still an unmet need for a disease-modifying intervention for older patients and those with severe diseases. In mice models, abatacept, a cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) immunoglobulin fusion protein, has been shown to promote immune tolerance to food when used as an adjuvant to allergen immunotherapy. The goal of this study is to explore the potential efficacy of abatacept in promoting immune tolerance to food allergens during OIT in humans.

Methods

In this phase 2a proof-of-concept study (NCT04872218), 14 peanut-allergic participants aged from 14 to 55 years will be randomized at a 1:1 ratio to abatacept vs. placebo for the first 24 weeks of a peanut OIT treatment (target maintenance dose of 300 mg peanut protein). The primary outcome will be the suppression of the OIT-induced surge in peanut-specific IgE/total IgE at 24 weeks, relative to the baseline. Sustained unresponsiveness will be assessed as a secondary outcome starting at 36 weeks by observing incremental periods of peanut avoidance followed by oral food challenges.

Discussion

This is the first study assessing the use of abatacept as an adjuvant to allergen immunotherapy in humans. As observed in preclinical studies, the ability of abatacept to modulate the peanut-specific immune response during OIT will serve as a proxy outcome for the development of clinical tolerance, given the small sample size. The study will also test a new patient-oriented approach to sustained tolerance testing in randomized controlled trials.

Allergen immunotherapy: progress and future outlook

INTRODUCTION

Allergy, the immunological hypersensitivity to innocuous environmental compounds, is a global health problem. The disease triggers, allergens, are mostly proteins contained in various natural sources such as plant pollen, animal dander, dust mites, foods, fungi and insect venoms. Allergies can manifest with a wide range of symptoms in various organs, and be anything from just tedious to life-threatening. A majority of all allergy patients are self-treated with symptom-relieving medicines, while allergen immunotherapy (AIT) is the only causative treatment option.

AREAS COVERED

This review will aim to give an overview of the state-of-the-art allergy management, including the use of new biologics and the application of biomarkers, and a special emphasis and discussion on current research trends in the field of AIT.

EXPERT OPINION

Conventional AIT has proven effective, but the years-long treatment compromises patient compliance. Moreover, AIT is typically not offered in food allergy. Hence, there is a need for new, effective and safe AIT methods. Novel routes of administration (e.g. oral and intralymphatic), hypoallergenic AIT products and more effective adjuvants holds great promise. Most recently, the development of allergen-specific monoclonal antibodies for passive immunotherapy may also allow treatment of patients currently not treated or treatable.

Food Allergen Immunotherapy in Preschool Children: Do We Have the Evidence?

Standard care for the management of food allergies previously centered on allergen avoidance and the treatment of adverse reactions after allergen exposure. An increase in the development of immunotherapy treatments for food allergy has occurred over the past 2 decades, with many centers now offering immunotherapy. Previous studies mainly focused on school-age children in whom food allergies are likely to be persistent. However, there is increasing evidence that delivering immunotherapy for food allergy to preschool-age children may deliver higher rates of success, and that peanut allergen immunotherapy leads the way. Conversely, the natural resolution of food allergies occurs primarily in these younger age groups, resulting in challenges to selecting patients who will ultimately benefit from these treatments. Both immunotherapy and natural history studies reveal the inherent plasticity of the immune system in early life, which may be more amenable to intervention, but this raises a delicate yet unknown balance between the optimal timing of intervention versus waiting for natural resolution of the food allergy. Here we review the evidence for early food allergen immunotherapy in preschoolers, and present the pros and cons of this approach while acknowledging important research gaps in this age group.

Current Practice in Pediatric Cow's Milk Protein Allergy-Immunological Features and Beyond

Cow's milk protein allergy is one of the most common pediatric food allergies. It poses a significant socioeconomic burden in industrialized countries and has a profound effect on the quality of life of affected individuals and their families. Diverse immunologic pathways can lead to the clinical symptoms of cow's milk protein allergy; some of the pathomechanisms are known in detail, but others need further elucidation. A comprehensive understanding of the development of food allergies and the features of oral tolerance could have the potential to unlock more precise diagnostic tools and novel therapeutic approaches for patients with cow's milk protein allergy.

Oral Immunotherapy in Food Allergy: Where Are We Now?

Food allergy (FA) has become more prevalent and problematic in the last 2 decades, and it poses important individual, social, and economic burdens. Besides treating reactions induced by accidental exposure and periodic evaluation for acquiring natural tolerance, the primary management approach is still allergen avoidance as a global standard. However, an active therapeutic approach that can raise the reaction threshold or accelerate tolerance is needed. This review aimed to provide an overview and the latest evidence of oral immunotherapy (OIT), which has recently been used in the active treatment of FA. FA immunotherapy, particularly OIT, is gaining considerable interest, and substantial effort has been made to integrate this active treatment into clinical practice. Consequently, growing evidence has been obtained regarding the efficacy and safety of OIT, particularly for allergens such as peanuts, eggs, and milk. However, several issues need to be addressed regarding the availability, safety, and long-term effects of this intervention. In this review, we summarize currently available information regarding tolerance-inducing immune mechanisms of OIT, data on efficacy and safety, gaps in current evidence, and ongoing research to develop new therapeutic molecules in order to enhance safety.

Efficacy and safety of food allergy oral immunotherapy in adults

BACKGROUND

Oral immunotherapy (OIT) is an emerging method for treating food allergy in children. However, data regarding adults undergoing this process are lacking.

METHODS

We retrospectively analyzed the medical records of patients with food allergy aged ≥17 years who completed OIT treatment between April 2010 and December 2020 at Shamir Medical Center. Data were compared with that of children aged 4 to <11 years and adolescents aged ≥11 to 17 treated during the same time period.

RESULTS

A total of 96 adults at a median age of 22.3 years who underwent OIT for milk (n = 53), peanut (n = 18), sesame (n = 7), egg (n = 5), and tree nuts (n = 13) were analyzed and compared with 1299 children and 309 adolescents. Adults experienced more adverse reactions requiring injectable epinephrine, both during in-clinic up-dosing (49% vs. 15.9% and 26.5% for children and adolescents, respectively, p < 0.0001) and during home treatment (22.9% vs. 12.4%, p = 0.007 for children, and 17.5%, p = 0.23 for adolescents). Most adults (61.5%) were fully desensitized, but the rates of full desensitization were significantly lower than children (73.4%, p = 0.013). Significantly more adults (28.3%) undergoing milk OIT failed treatment than children (14.3%, p = 0.015) and adolescents (14.1%, p = 0.022), while failure rates in adults undergoing OIT for other foods were low (9.3%) and comparable with children and adolescents.

CONCLUSIONS

OIT is successful in desensitizing most adults with IgE-mediated food allergy. Adults undergoing milk OIT are at increased risk for severe reactions and for OIT failure while failure rates in adults undergoing OIT for other foods are low.

Food Allergies and Quality of Life among School-Aged Children and Adolescents: A Systematic Review

Recently, besides the focus on the medical diagnosis and therapeutic interventions for food allergy (FA), the psychosocial aspects of this frequent condition have also been investigated. The current systematic review aimed to explore and synthesize the scientific evidence published from January 2015 to April 2022 on Health-Related Quality of Life (HRQoL) among children and adolescents with FAs. Twenty-eight research studies were included in the review, which was conducted on three databases (PubMed, Scopus and Cochrane Library). In most studies, the scores indicate an average level of HRQoL for children and adolescents with FAs, with girls and older children being more negatively affected than boys and younger ones, respectively. Few studies compared HRQoL between children with FA and healthy children, with 3 of them showing worse HRQoL for children with FAs. Immunotherapy has been found to improve the QoL of children with FAs. Anaphylaxis history, number of FAs, additional allergies, number and severity of symptoms were identified as the main factors with a negative impact on QoL. More comparative studies on the HRQoL of children and adolescents with FAs and healthy populations or children with other chronic diseases are required in order to improve QoL of children with FAs.

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.

Long-term changes in milk component immunoglobulins reflect milk oral immunotherapy outcomes in Finnish children

BACKGROUND

Milk oral immunotherapy (OIT) may increase the amount of milk protein that can be ingested without triggering an allergic reaction. It is important to understand why some patients benefit from the treatment while others do not.

OBJECTIVE

The aim was to define the differences in the milk allergen component-specific (casein, α-lactalbumin, ß-lactoglobulin) immunoglobulin (sIg [sIgE, sIgG4, and sIgA]) levels relative to the long-term outcomes of milk OIT.

METHODS

In this long-term, open-label follow-up study, 286 children started milk OIT between 2005 and 2015. Follow-up data were collected at two points: the post-buildup phase and long term (range 1-11 years, median 6 years). Comparisons of sIg levels were made among three outcome groups of self-reported long-term milk consumption (high-milk dose, low-milk dose, and avoidance).

RESULTS

A total of 168 (59%) of the 286 patients on OIT participated. Most patients (57%) were in the high-dose group; here, 80% of these patients had a baseline casein sIgE value less than 28 kUA/L, they had the lowest casein sIgE levels at all time (p < .001), their casein sIgG4/IgE levels increased, and long-term casein sIgA was highest compared with the low-dose and avoidance groups (p = .02). Low-milk dose group had the highest casein sIgG4/IgE levels in long term (p = .002).

CONCLUSION

The baseline Ig profiles and responses to milk OIT differed depending on long-term milk consumption. Lower casein sIgE levels were associated with better outcome. Milk casein sIgA differed in the long term among high-milk consumers.

Endpoints and Outcomes After Immunotherapy for Food Allergy: What Is Meaningful for Patients?

Multiple novel interventions for food allergy are currently at various stages of development with the goal of reducing or eliminating allergic reactions. However, the relative success of these therapeutics in achieving meaningful, long-term improvements to patients' lives is difficult to determine as there is currently very limited understanding of the degree of alignment between clinical trial efficacy endpoints and patient-centered outcomes. Furthermore, outcome measures used in clinical trials of food allergy immunotherapies vary widely, are often misinterpreted, and not necessarily consistent with what patients expect to achieve through treatment. This review aims to assist clinicians in critically interpreting outcomes reported in clinical trials and accurately communicating risks and outcomes to patients when practicing shared decision-making.

Characteristics of patients diagnosed as non-allergic following food allergy oral immunotherapy referral

BACKGROUND

Ascribing food allergy diagnosis to patients who are not allergic is well described, but its implications on oral immunotherapy (OIT) have not been studied. The aim was to study non-allergic patients referred for OIT.

METHODS

All patients who began OIT at Shamir Medical Center between November 2015 and August 2020 were included. Medical records were reviewed, and skin prick tests (SPT) and/or specific IgE were measured. Patients were challenged to the index food. Allergic and non-allergic patients were compared.

RESULTS

A total of 1073 patients were studied (milk, n = 327; egg, n = 41; peanut, n = 272; sesame, n = 130; and tree nuts, n = 303) and 87 (8.1%) were found non-allergic (milk, n = 21; egg, n = 6; sesame, n = 5; peanut, n = 29; tree nuts, n = 26). Predictors of being not allergic were no previous reaction to the index food (OR = 3.3, p = 0.001), not having asthma (OR = 2.4, p = 0.001), or HDM sensitization (OR = 2.0, p = 0.007), male sex (OR = 2.3, p = 0.004), and a smaller SPT wheal size (OR = 1.5, p < 0.001).

CONCLUSIONS

A substantial number of patients referred for OIT are mislabeled with food allergy, suffer from unjustly food limitations and impairments in quality of life, and "take up" OIT places of true allergic patients. Awareness of OIT centers to this phenomenon is important.

IMPACT

A significant number (8.1%) of patients referred for OIT are found not allergic to the food they intended to treat. This study characterizes non-allergic patients referred for OIT (a lack of previous reaction to the index food, a smaller or negative SPT wheal size, and less atopic co-morbidities) and discusses the implications of such referrals. Increased awareness by OIT centers to potential non-allergic patients referred for OIT is required, including screening of patients before treatment initiation, to minimize unnecessary treatments of non-allergic patients.

Management of IgE-mediated food allergy in the 21st century

The 21st century has seen the propulsion of research in the field of food allergy, which has driven real changes in the clinical approach. Allergen immunotherapy has been recommended for the active management of food allergy. Data have shown promising additional methods of treatment, including biologics. Efforts have been devoted to the risk stratification of food allergy and the standardization of the assessment of food-allergic severity. Alternative routes of administration of epinephrine are under investigation to minimize any mechanical issue and the fear of injections. Evidence-based guidelines have been published by the main international societies in the field of anaphylaxis and food allergy management and new updates are in preparation. In the coming years, treatment options that are currently in pre-clinical or early clinical evaluation will hopefully lead to safe and effective disease-modifying therapies for food allergy in clinical practice. The identification of reliable biomarkers and the standardization of definitions and measurement approaches, alongside a shared decision-making with patients and families, will be key for the development of personalized care and to help minimize the substantial burden of food allergy.

Extensively Hydrolyzed Hypoallergenic Infant Formula with Retained T Cell Reactivity

BACKGROUND

Immunoglobulin E (IgE)-mediated cow's milk allergy (CMA) can be life-threatening and affects up to 3% of children. Hypoallergenic infant formulas based on hydrolyzed cow's milk protein are increasingly considered for therapy and prevention of cow's milk allergy. The aim of this study was to investigate the allergenic activity and ability to induce T cell and cytokine responses of an infant formula based on extensively hydrolyzed cow's milk protein (whey) (eHF, extensively hydrolyzed formula) supplemented with Galactooligosaccharides (GOS) and Limosilactobacillus fermentum CECT5716 (LF) to determine its suitability for treatment and prevention of CMA.

METHODS

eHF and standard protein formula based on intact cow's milk proteins (iPF) with or without Galactooligosaccharide (GOS) and Limosilactobacillus fermentum CECT5716 (LF) were investigated with allergen-specific antibodies and tested for IgE reactivity and allergenic activity in basophil degranulation assays with sera from cow's milk (CM)-allergic infants/children. Their ability to stimulate T cell proliferation and cytokine secretion in cultured peripheral blood mononuclear cells (PBMC) from CM-allergic infants and children was studied with a FACS-based carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution assay and xMAP Luminex fluorescent bead-based technology, respectively.

RESULTS

An eHF supplemented with GOS and LF exhibiting almost no IgE reactivity and allergenic activity was identified. This eHF induced significantly lower inflammatory cytokine secretion as compared to an intact protein-based infant formula but retained T cell reactivity.

CONCLUSIONS

Due to strongly reduced allergenic activity and induction of inflammatory cytokine secretion but retained T cell reactivity, the identified eHF may be used for treatment and prevention of CMA by induction of specific T cell tolerance.

Methylation changes induced by a glycodendropeptide immunotherapy and associated to tolerance in mice

Introduction

Allergen-specific immunotherapy (AIT) is applied as treatment to rise tolerance in patients with food allergies. Although AIT is thoroughly used, the underlying epigenetic events related to tolerant induction are still unknown. Thus, we aim to investigate epigenetic changes that could be related to tolerance in dendritic cells (DCs) from anaphylactic mice to lipid transfer proteins, Pru p 3, in the context of a sublingual immunotherapy (SLIT) with a glycodendropeptide (D1ManPrup3) that has demonstrated tolerant or desensitization responses depending on the treatment dose.

Methods

Changes in DNA methylation in CpG context were determined comparing Sensitized (Antigen-only) animals and two groups receiving SLIT with the D1ManPrup3 nanostructure (D1ManPrup3-SLIT): Tolerant (2nM D1ManPrup3) and Desensitized (5nM D1ManPrup3), against anaphylactic animals. DNA from lymph nodes-DCs were isolated and then, Whole Genome Bisulphite Sequencing was performed to analyze methylation.

Results

Most differentially methylated regions were found on the area of influence of gene promoters (DMPRs). Compared to the Anaphylactic group, the highest value was found in Desensitized mice (n = 7,713 DMPRs), followed by Tolerant (n = 4,091 DMPRs) and Sensitized (n = 3,931 DMPRs) mice. Moreover, many of these epigenetic changes were found in genes involved in immune and tolerance responses (Il1b, Il12b, Il1a, Ifng, and Tnf) as shown by functional enrichment (DCs regulation, B cell-mediated immunity, and effector mechanisms).

Discussion

In conclusion, different doses of D1ManPrup3-SLIT induce different DNA methylation changes, which are reflected in the induction of distinct responses, tolerance, or desensitization.

Management of Adult Patients with Gastrointestinal Symptoms from Food Hypersensitivity-Narrative Review

The incidence of food hypersensitivity has increased dramatically over the years not only among children but also in adults. Adult patients are usually less suspected of food hypersensitivity symptoms since food allergies are more typical for small children, with a tendency to outgrow the condition. The aim of this article is to increase awareness of hypersensitivity to food symptoms and their diagnosis and treatment possibilities among gastroenterologists and other health care professionals dealing with this type of patient. Symptoms of many gastrointestinal disorders, especially functional, may be driven by different types of mechanisms, and food intolerance or allergy should be considered as a potential cause. This article presents the current understanding of the epidemiology, diagnosis and treatment of immune- and non-immune-mediated food-induced diseases. Diagnosis of food hypersensitivity is based mainly on medical history, different types of sensitivity tests, e.g., hydrogen breath test, specific IgE (sIgE) serum concentration, tissue eosinophil count, skin tests and oral food challenges considered as a "gold standard" for food allergy. Elimination diet and pharmacologic treatment for allergy symptoms are first-line therapies. Eosinophilic gastrointestinal diseases are often caused by non-IgE-mediated food allergies, require endoscopic biopsy samples to confirm diagnosis and proper elimination diet often combined with steroids or proton pump inhibitor agents for treatment. Mast cell activation syndrome (MCAS) derives from pathologic reaction of mast cells with increased tryptase serum level as a marker. Symptoms may occur in the digestive, respiratory, skin, neurologic and cardiovascular system. Treatment is based on histamine type 1, type 2 (H1, H2) receptor antagonists and other mast cell stabilizing agents. Carbohydrate intolerances are the most common type of food hypersensitivity in adult patients, and an elimination diet is effective for reducing symptoms. Food additives hypersensitivity remains difficult to diagnose, but use of a diet low in chemical substances alleviates symptoms and helps to diagnose the triggering factors.

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.

Sialic acid and food allergies: The link between nutrition and immunology

Food allergies (FA), a major public health problem recognized by the World Health Organization, affect an estimated 3%-10% of adults and 8% of children worldwide. However, effective treatments for FA are still lacking. Recent advances in glycoimmunology have demonstrated the great potential of sialic acids (SAs) in the treatment of FA. SAs are a group of nine-carbon α-ketoacids usually linked to glycoproteins and glycolipids as terminal glycans. They play an essential role in modulating immune responses and may be an effective target for FA intervention. As exogenous food components, sialylated polysaccharides have anti-FA effects. In contrast, as endogenous components, SAs on immunoglobulin E and immune cell surfaces contribute to the pathogenesis of FA. Given the lack of comprehensive information on the effects of SAs on FA, we reviewed the roles of endogenous and exogenous SAs in the pathogenesis and treatment of FA. In addition, we considered the structure-function relationship of SAs to provide a theoretical basis for the development of SA-based FA treatments.

Elicitors and phenotypes of adult patients with proven IgE-mediated food allergy and non-immune-mediated food hypersensitivity to food additives

BACKGROUND

Food allergy is a growing health concern with a prevalence of 2%-3% in the adult population in Europe. Non-immune-mediated food hypersensitivities, which include reactions after ingestion of food additives, affect 1% of adults and may resemble IgE-induced allergic reactions without identifiable immunologic sensitization. A double-blind placebo-controlled food challenge (DBPCFC) is the gold standard for the diagnosis of any food hypersensitivity.

OBJECTIVE

We analysed a large group of adult patients with suspected food hypersensitivity, who had undergone DBPCFC, to better understand IgE-mediated food allergy and non-immune-dependent food hypersensitivity to food additives in adults regarding elicitors, symptoms and positivity rates of oral challenges.

METHODS

Data from 541 patients with suspected food hypersensitivity were analysed, who underwent an oral food challenge between 2010 and 2019.

RESULTS

IgE-dependent food allergy was confirmed in 114 of 329 adult patients (34.6%). The confirmation rate was lower in the group of patients with suspected non-immune-mediated reactions to food additives (65 of 286, 22.7%). Urticaria and angioedema appeared more frequently in patients with IgE-mediated food allergies. By contrast, flush and diarrhoea were the most frequent symptoms after a challenge in the group with the non-immune-mediated reactions to food additives. Wheat and celery were the most frequently identified food allergens in adults, whereas colourings and preservatives were the most frequent elicitors of non-immune-mediated food hypersensitivity.

CONCLUSION

The importance of oral food challenges for the diagnosis of food hypersensitivity is confirmed. IgE-dependent food allergy is more frequently proven, reaching a positivity rate of one-third and only about 20% for non-immune-mediated hypersensitivity. Future studies should elaborate on the mechanisms of non-immune-mediated food hypersensitivity and the clinical impact of cofactors in this setting.

Recent Advances in the Allergic Cross-Reactivity between Fungi and Foods

Airborne fungi are one of the most ubiquitous kinds of inhalant allergens which can result in allergic diseases. Fungi tend to grow in warm and humid environments with regional and seasonal variations. Their nomenclature and taxonomy are related to the sensitization of immunoglobulin E (IgE). Allergic cross-reactivity among different fungal species appears to be widely existing. Fungus-related foods, such as edible mushrooms, mycoprotein, and fermented foods by fungi, can often induce to fungus food allergy syndrome (FFAS) by allergic cross-reactivity with airborne fungi. FFAS may involve one or more target organs, including the oral mucosa, the skin, the gastrointestinal and respiratory tracts, and the cardiovascular system, with various allergic symptoms ranging from oral allergy syndrome (OAS) to severe anaphylaxis. This article reviews the current knowledge on the field of allergic cross-reactivity between fungal allergens and related foods, as well as the diagnosis and treatment on FFAS.

Biomarkers and mechanisms of tolerance induction in food allergic patients drive new therapeutic approaches

Immunotherapy for food-allergic patients has been effective in inducing desensitization in some populations, but long-term tolerance has remained an elusive target. A challenge facing our field is how to differentiate immune markers that are impacted by immunotherapy from those that are critical biomarkers of tolerance. Data from recent clinical trials have identified several biomarkers and mechanisms for achieving tolerance. These biomarkers include younger age, lower food-specific IgE, lower food component-specific IgE, specific linear epitope profiles, and subsets of food-specific CD4+ T cells. Additional biomarkers under investigation for their relevance in tolerance induction include TCR repertoires, gastrointestinal and skin microbiome, and local tissue immunity. This mini-review highlights recent advances in understanding biomarkers and mechanisms of tolerance induction in food immunotherapy and how these are influencing clinical trial development.

Biomarkers in oral immunotherapy

Food allergy (FA) is a global health problem that affects a large population, and thus effective treatment is highly desirable. Oral immunotherapy (OIT) has been showing reasonable efficacy and favorable safety in most FA subjects. Dependable biomarkers are needed for treatment assessment and outcome prediction during OIT. Several immunological indicators have been used as biomarkers in OIT, such as skin prick tests, basophil and mast cell reactivity, T cell and B cell responses, allergen-specific antibody levels, and cytokines. Other novel indicators also could be potential biomarkers. In this review, we discuss and assess the application of various immunological indicators as biomarkers for OIT.