Efficacy and safety of high-dose rush oral immunotherapy in persistent egg allergic children

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.

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.

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.

The Natural History and Risk Factors for the Development of Food Allergies in Children and Adults

PURPOSE OF REVIEW

This narrative review explores food allergy prevalence and natural history stratified by life stages, especially in context of evolving knowledge over the last few decades.

RECENT FINDINGS

The prevalence of food allergy remains highest in early childhood with common food triggers being cow's milk, soy, hen's egg, wheat, peanut, tree nuts, sesame, fish, and shellfish. This correlates with certain risk factors especially pertinent in the postnatal period which appear to predispose an individual to developing a food allergy. Some allergies (such as milk and egg) were previously thought to be easily outgrown in early life; however, recent studies suggest increasing rates of persistence of these allergies into young adulthood; the reason behind this is unknown. Despite this, there is also evidence demonstrating that food allergies can be outgrown in adolescents and adults. An understanding of the paradigm shifts in the natural history of food allergy allows clinicians to provide updated, age-appropriate, and tailored advice for patients on the management and prognosis of food allergy.

Low-dose oral immunotherapy in immunoglobulin E-mediated food allergies

Nowadays, the management of food allergies has increasingly moved from conventional oral immunotherapy (OIT) to low-dose OIT or low-dose OIT utilizing hypoallergenic foods. This shift is largely because the latter appears to induce oral tolerance with fewer adverse effects than the former. However, the mechanisms underpinning such differences remain unclear. To better understand these mechanisms, we conducted a comparative study scrutinizing the mechanisms of OIT, especially those of low-dose desensitization. We also summarized articles on low-dose OIT and low-dose OIT using hypoallergenic foods. We examined the efficacy, safety, and immunological parameters of low-dose OIT and those of low-dose OIT with hypoallergenic foods with the aim of shedding some light on low-dose OIT and its therapeutic application in inducing oral tolerance for individuals with food allergies.

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.

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.

Clinical outcomes of efficacy in food allergen immunotherapy trials

PURPOSE OF REVIEW

With food allergy affecting millions of children worldwide, the consolidation of food allergen immunotherapy represents an encouraging therapeutic option, that might expand in the next few years to reach greater number of candidates. This review aims at providing a critical overview of the efficacy outcomes employed in food allergen immunotherapy trials (AIT).

RECENT FINDINGS

Understanding efficacy endpoints rely on identifying what and how these are being measured. Desensitization, as the efficacy of the therapy to increase the patient's reactivity threshold to the food during therapy, and Sustained Unresponsiveness, withholding such efficacy even if the therapy is withdrawn, are nowadays considered the main parameters of efficacy evaluation. Quality of life is a promising variable to capture food AIT impact from the patient's perspective.There is a relevant degree of heterogeneity across studies in outcomes definitions and also in oral food challenges design, the tool that is more spread to assess results, hampering study comparison.

SUMMARY

Interpreting the results of a clinical trial, and comparing data from different studies is an important task, both for the researcher and the clinician, that should be done after a careful analysis of the outcomes and the evaluation tools used.

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.

Oral Immunotherapy

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.

Cow's milk and egg protein threshold dose distributions in children tolerant to beef, baked milk, and baked egg

BACKGROUND

The use of eliciting doses (EDs) for food allergens is necessary to inform individual dietary advice and food allergen risk-management. The Eliciting Dose 01 (ED01) for milk and egg, calculated from populations of allergic subjects undergoing oral food challenges (OFCs), are 0.2 mg total protein. The respective Eliciting Dose 05 (ED05) is 2.4 mg for milk and 2.3 mg for egg. As about 70% children allergic to such foods may tolerate them when baked, we sought to verify the EDs of that subpopulation of milk and egg-allergic children.

METHODS

We retrospectively assessed consecutive OFC for fresh milk and egg between January 2018 and December 2020 in a population of baked food-tolerant children.

RESULTS

Among 288 children (median age 56 - IQR 36-92.5 months, 67.1% male) included, 87 (30.2%) returned positive OFC results, 38 with milk and 49 with egg. The most conservative ED01 was 0.3 mg total protein (IQR 0.03-2.9) for milk and 14.4 mg total protein (IQR 3.6-56.9) for egg. The respective ED05 was 4.2 (IQR 0.9-19.6) mg for milk and 87.7 (IQR 43-179) mg for egg. Such thresholds are, respectively, 1.5 (milk ED01), 1.75 (milk ED05), 72 (egg ED01), and 38.35 (egg ED05) times higher than the currently used thresholds.

CONCLUSIONS

The subpopulation of children allergic to milk and egg, but tolerant to baked proteins, displays higher reactivity thresholds than the general population of children allergic to milk and egg. Their risk stratification, in both individual and population terms, should consider this difference. In baked milk-tolerant children, milk causes reactions at lower doses than egg in our group of egg-tolerant children. This could be associated with the relative harmlessness of egg compared with milk in the determinism of fatal anaphylactic reactions in children.

A practical focus on egg oral immunotherapy

Egg allergy usually develops in the first year of life, with an estimated prevalence of 2.6%-9%. Rates of resolution and timing vary, with approximately one-third of patients outgrowing their egg allergy by age 6 years. Persistent egg allergy has been associated with high egg white specific immunoglobulin E levels and sensitization to the egg allergen component Gal d 1, which is resistant to heat and digestion. These individuals seem to have a more severe and persistent phenotype of egg allergy. Recently, an active approach has emerged for patients with food allergy, including those with egg allergy, in the form of oral immunotherapy. Egg oral immunotherapy consists of the administration of gradually increasing doses of egg, with the aim to enable patients to consume small amounts of egg without having allergic reactions, which thus provides protection from accidental exposures to egg-containing foods. This article aims to discuss published evidence on egg oral immunotherapy, provide practical information on dosing protocols, and address special challenges associated with this intervention.

Variations in protocol development during oral immunotherapy

Oral immunotherapy (OIT) protocols are not standardized, and a wide heterogeneity exists in the literature. OIT protocol variables include the initiation approach (fixed dose versus oral food challenge), buildup speed (slow versus fast), target maintenance dose (low versus high target dose), type of food used, and use of adjuvants among other variables. Most protocols start with an initial escalation day, which is a series of extremely low doses to safely identify the patients who are most allergic, followed by a buildup period over several months to years until the final target maintenance dose is achieved. Doses are generally increased every 1-2 weeks by a factor of 1.25 to 2 and are adapted based on the patient's symptoms. Protocols are increasingly favoring low-maintenance doses over traditional high maintenance doses, although this needs to be discussed and adapted based on the patient's preferences. Accelerated OIT schedules with using a short treatment of omalizumab can be considered in severe food allergy cases.

A review of the safety of oral immunotherapy in clinical trial and real-world studies

Safety concerns are a barrier to oral immunotherapy (OIT). This review aims to describe OIT safety events and explore potential risk factors and mitigating factors. Published clinical and real-world OIT studies were reviewed for data on safety outcomes in OIT. Gastrointestinal symptoms are one of the most common adverse reactions associated with OIT, and persistent symptoms can be associated with an eosinophilic response. Allergic reactions are increased in OIT compared with avoidance; however, these symptoms tend not to be severe and to decrease over time. Despite OIT, epinephrine usage persists in studies and life-threatening reactions (though rare) have occurred. High baseline food specific immunoglobulin E levels, aggressive dosing, uncontrolled atopic comorbidities, and poor adherence to protocols may contribute to the severity of adverse events. OIT remains a shared decision that incorporates best medical evidence and appropriate patient selection. It requires individualized care and action plans to ensure safe outcomes.

Allergen immunotherapy and/or biologicals for IgE-mediated food allergy: A systematic review and meta-analysis

Background

There is substantial interest in immunotherapy and biologicals in IgE‐mediated food allergy.

Methods

We searched six databases for randomized controlled trials about immunotherapy alone or with biologicals (to April 2021) or biological monotherapy (to September 2021) in food allergy confirmed by oral food challenge. We pooled the data using random‐effects meta‐analysis.

Results

We included 36 trials about immunotherapy with 2126 mainly child participants. Oral immunotherapy increased tolerance whilst on therapy for peanut (RR 9.9, 95% CI 4.5.–21.4, high certainty); cow's milk (RR 5.7, 1.9–16.7, moderate certainty) and hen's egg allergy (RR 8.9, 4.4–18, moderate certainty). The number needed to treat to increase tolerance to a single dose of 300 mg or 1000 mg peanut protein was 2.

Oral immunotherapy did not increase adverse reactions (RR 1.1, 1.0–1.2, low certainty) or severe reactions in peanut allergy (RR 1,6, 0.7–3.5, low certainty), but may increase (mild) adverse reactions in cow's milk (RR 3.9, 2.1–7.5, low certainty) and hen's egg allergy (RR 7.0, 2.4–19.8, moderate certainty). Epicutaneous immunotherapy increased tolerance whilst on therapy for peanut (RR 2.6, 1.8–3.8, moderate certainty). Results were unclear for other allergies and administration routes.

There were too few trials of biologicals alone (3) or with immunotherapy (1) to draw conclusions.

Conclusions

Oral immunotherapy improves tolerance whilst on therapy and is probably safe in peanut, cow's milk and hen's egg allergy. More research is needed about quality of life, cost and biologicals.

Oral Immunotherapy in Food Allergy: A Critical Pediatric Perspective

There is evidence that in children with persistent IgE-mediated food allergy (FA) to cow's milk, hen's egg, and peanut, oral allergen-specific immunotherapy (OIT) may increase the reaction threshold to the culprit food allergen(s). OIT may protect patients from the occurrence of severe reactions in case of accidental ingestion of the culprit food during treatment. Notwithstanding, many gaps are still unsolved, including safety issues, identification of predictive biomarkers, and post-desensitization efficacy. In this perspective, the use of omalizumab (Anti-IgE monoclonal antibody) has been proposed as an adjunctive treatment to OIT in order to reduce the risk of allergic reactions related to OIT. This review aims to summarize the current evidence and unmet needs on OIT in children with FA to enhance the development of longitudinal, prospective, and well-designed studies able to fill the current gaps soon.

Oral immunotherapy in children with a food allergy-Where do we stand? - Review

The number of hospitalisations due to an anaphylactic reaction to food is continuously increasing. Therefore, there is an urgent need to seek effective therapy. Currently, the only way to treat food allergies is to avoid allergens and to administer intramuscular adrenaline if an accidental allergen intake occurs. The only causal therapeutic strategy is specific oral immunotherapy. An increasing amount of data confirms this therapy's effectiveness and safety, but the results remain inconclusive due to the lack of long-term follow-up. In this state-of-the-art review, we briefly summarise the latest placebo-controlled randomised controlled trials on oral immunotherapy (OIT) to treat food allergy. During the paper's review, we asked the following questions: does the therapy permanently increase the amount of allergen consumed without symptoms? Does it significantly increase or decrease the occurrence of severe systemic reactions - requiring the administration of adrenaline or hospitalisation? Many authors describe outcomes such as an increase in the amount of allergen that can be safely ingested; however, significant clinical benefits such as decreased hospitalisations or anaphylaxis incidence are rarely included in the results. To date, there is no unified protocol of therapy, which makes comparisons between studies difficult because of significant differences in types, doses, and routes of administration of the allergen, timeline for up-dosing and maintenance, duration of the therapy, and primary outcomes of OIT.

Home-Based Up-Dosing in Build-Up Phase of Oral Immunotherapy of Egg Allergy Is Safe and Feasible in Real-World Practice

Oral immunotherapy (OIT) has emerged to build sustained unresponsiveness or tolerance in patients with egg allergy. However, it is important to increase compliance and ensure safety because OIT requires an extended period of time and has a risk of side effects like anaphylaxis. We aimed to show the feasibility and safety of OIT during the build-up phase using a home-based, up-dosing method in children with egg allergy. Sixteen patients aged 4 to 12 years with egg allergy were enrolled. Patients increased the dose of boiled egg white (EW) by 5% per day at home and 25% per month at the hospital, with a target dose of 40 g of boiled EW (4.0 g of EW proteins). A historical control group (n = 16) was matched for age, sex, and clinical characteristics for comparisons with the OIT group. Oral food challenge (OFC) tests were performed after completing the build-up phase. In the OIT group, 93.8% (15/16) of patients achieved desensitization, with only 1 patient discontinuing OIT before the maintenance phase due to repeated allergic reactions. Mild allergic reactions and anaphylaxis occurred in 12 (75.0%) and 2 patients (12.5%), respectively. However, there were no significant adverse reactions such as serious anxiety or life-threatening events that required discontinuation of treatment. On the contrary, only 1 patient (6.3%) in the control group passed an OFC of 40 g of boiled EW during the same period (P < 0.001). Our results suggest that home-based up-dosing protocols using boiled eggs may be safe and feasible for the build-up phase of OIT in children with egg allergy.

Peanut Can Be Used as a Reference Allergen for Hazard Characterization in Food Allergen Risk Management: A Rapid Evidence Assessment and Meta-Analysis

Regional and national legislation mandates the disclosure of “priority” allergens when present as an ingredient in foods, but this does not extend to the unintended presence of allergens due to shared production facilities. This has resulted in a proliferation of precautionary allergen (“may contain”) labels (PAL) that are frequently ignored by food-allergic consumers. Attempts have been made to improve allergen risk management to better inform the use of PAL, but a lack of consensus has led to variety of regulatory approaches and nonuniformity in the use of PAL by food businesses. One potential solution would be to establish internationally agreed “reference doses,” below which no PAL would be needed. However, if reference doses are to be used to inform the need for PAL, then it is essential to characterize the hazard associated with these low-level exposures. For peanut, there are now published data relating to over 3000 double-blind, placebo-controlled challenges in allergic individuals, but a similar level of evidence is lacking for other priority allergens. We present the results of a rapid evidence assessment and meta-analysis for the risk of anaphylaxis to a low-level allergen exposure for priority allergens. On the basis of this analysis, we propose that peanut can and should be considered an exemplar allergen for the hazard characterization at a low-level allergen exposure.

Oral Immunotherapy in Patients with IgE Mediated Reactions to Egg White: A Clinical Trial Study

BACKGROUND

Oral immunotherapy (OIT) is under consideration as a promising treatment for desensitization of egg-allergic patients. The objective of this study was to assess the effectiveness of egg-white OIT in patients with IgE-mediated allergy to egg white and to compare the clinical and laboratory findings before and after OIT.

METHODS

This clinical trial was performed from February to August 2018 in Rasool e Akram Hospital, Tehran, Iran. Patients' selection criteria included a history of allergic symptoms, skin prick test (SPT) reactivity to egg white, and the inability to pass the Oral Food Challenge (OFC). Egg-white OIT was done for eight patients in the OIT group for 6 months while egg-white-free products were administrated for controls. The SPT reactivity, specific IgE, and IgG4 for egg white and ovomucoid were evaluated before and after OIT.

RESULTS

Hundred percent of the subjects in OIT group were desensitized and tolerated 40 cc raw egg white following 6-month maintenance whereas none of the controls was able to pass the OFC. The findings obtained from the evaluations indicated a significant decrease in the wheal size and specific IgE to egg white after OIT (P = .001). Furthermore, a significant decrease of IgE/IgG4 ratio to egg white was found in OIT group (P = .01).

CONCLUSION

This OIT protocol was successful as all OIT patients were able to continue 6-month OIT process and the reaction threshold to egg white increased in the OIT group. Therefore, it could be regarded as an effective and safe protocol to treat egg-allergic patients.

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

Purpose of Review

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

Recent Findings

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

Summary

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

Oral immunotherapy in food allergies: A practical update for pediatricians

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

Array-based measurements of aero-allergen-specific IgE correlate with skin-prick test reactivity in asthma regardless of specific IgG4 or total IgE measurements

Skin prick testing (SPT) and measurement of serum allergen-specific IgE (sIgE) are used to investigate asthma and other allergic conditions. Measurement of serum total IgE (tIgE) and allergen-specific IgG4 (sIgG4) may also be useful. The aim was to ascertain the correlation between these serological parameters and SPT. Sera from 60 suspected asthmatic patients and 18 healthy controls were assayed for sIgE and sIgG4 reactivity against a panel of 70 SPT allergen preparations, and for tIgE. The patients were also assessed by skin prick tests for reactivity to cat, dog, house dust mite and grass allergens. Over 50% of the patients had tIgE levels above the 75th percentile of the controls. 58% of patients and 39% of controls showed sIgE reactivity to ≥1 allergen. The mean number of allergens detected by sIgE was 3.1 in suspected asthma patients and 0.9 in controls. 58% of patients and 50% of controls showed sIgG4 reactivity to ≥1 allergen. The mean number of allergens detected by sIgG4 was 2.5 in patients and 1.7 in controls. For the patients, a strong correlation was observed between clinical SPT reactivity and serum sIgE levels to cat, dog, house dust mite (HDM) and grass allergens. SPT correlations using sIgE/sIgG4 or sIgE/tIgE ratios were not markedly higher. The measurement of serum sIgE by microarray using SPT allergen preparations showed good correlation with clinical SPT reactivity to cat, dog, HDM and grass allergens. This concordance was not improved by measuring tIgE or sIgG4.

A Randomized, Open-Label Trial of Hen's Egg Oral Immunotherapy: Efficacy and Humoral Immune Responses in 50 Children

BACKGROUND

Egg allergy is the second most common food allergy in children. Persistent food allergy increases the risk of anaphylaxis and reduces the quality of life.

OBJECTIVE

To determine the efficacy of oral immunotherapy (OIT) with raw egg white powder and study its effects on humoral responses in children with persistent egg allergy.

METHODS

Fifty children aged 6 to 17 years with egg allergy, diagnosed by double-blind, placebo-controlled food challenge, were randomized 3:2 to 8 months of OIT with a maintenance dose of 1 g of egg white protein or 6 months of avoidance after which the avoidance group crossed over to OIT. We examined changes in IgE, IgG₄, and IgA concentrations to Gal d 1-4 during OIT compared with avoidance and assessed clinical reactivity at 8 and 18 months.

RESULTS

After 8 months, 22 of 50 children (44%) on OIT and 1 of 21 (4.8%) on egg avoidance were desensitized to the target dose, 23 of 50 (46%) were partially desensitized (dose <1 g), and 5 of 50 (10%) discontinued. IgG₄ concentrations to Gal d 1-4 and IgA to Gal d 1-2 increased significantly, whereas IgE to Gal d 2 decreased. A heatmap analysis of the IgE patterns revealed 3 distinct clusters linked with the clinical outcome. High baseline egg white-specific IgE and polysensitization to Gal d 1-4 related with failure to achieve the maintenance dose at 8 months. After 18 months of treatment, 36 of 50 patients (72%) were desensitized and 8 of 50 (16%) partially desensitized.

CONCLUSIONS

OIT with raw egg enables liberation of egg products into the daily diet in most patients. Subjects with high egg white-specific IgE concentrations and sensitization to multiple egg allergen components at baseline benefit from prolonged treatment.

Evaluation of oral immunotherapy efficacy and safety by maintenance dose dependency: A multicenter randomized study

Background

Generally, oral immunotherapy (OIT) aims for daily administration. Recently, the efficacy of treatment with OIT at a low dose has been reported. However, the optimal dose and the evaluation of dose-dependent OIT outcome have not been described.

Methods

A multicenter, parallel, open-labeled, prospective, non-placebo controlled, randomized study enrolled 101 Japanese patients for treatment with OIT. We hypothesized that target dose OIT would induce short-term unresponsiveness (StU) earlier than reduced dose OIT. StU was defined as no response to 6200 mg whole egg, 3400 mg milk, and 2600 mg wheat protein, as evaluated by oral food challenge after 2-week ingestion cessation. To compare the two doses of OIT efficacy, the maximum ingestion doses during the maintenance phase of OIT were divided into 100%-dose or 25%-dose groups against their target StU dose, respectively. A total of 51 patients were assigned to the 100%-dose group [hen's egg (HE) = 26, cow's milk (CM) = 13, wheat = 12] and 50 to the 25%-dose group (HE = 25, CM = 13, wheat = 12). Primary outcome was established by comparing StU at 1 year. Secondary outcome was StU at 2 years and established by comparing allergic symptoms and immunological changes.

Results

The year 1 StU rates (%) for the 100%- and 25%-dose groups were 26.9 vs. 20.0 (HE), 7.7 vs. 15.4 (CM), and 50.0 vs. 16.7 (wheat), respectively. The year 2 StU rates were 30.8 vs. 36.0 (HE), 7.7 vs. 23.1 (CM), and 58.3 vs. 58.3 (wheat), respectively. There were no statistically significant differences in StU between years 1 and 2. The total allergic symptom rate in the 25%-dose group was lower than that in the 100%-dose group for egg, milk, and wheat. Antigen-specific IgE levels for egg-white, milk, and wheat decreased at 12 months.

Conclusions

Reduced maintenance dose of egg OIT showed similar therapeutic efficacy to the target dose. However, we were not able to clearly demonstrate the efficacy, particularly for milk and wheat. Reducing the maintenance dose for eggs, milk, and wheat may effectively lower the symptoms associated with their consumption compared to the target OIT dose. Furthermore, aggressive reduction of the maintenance dose might be important for milk and wheat, compared to the 25%-dose OIT.

Trial registration

UMIN000009373, Multicenter Oral Immunotherapy for Hen's Egg, Cow's Milk, and Wheat-Allergic Children at Outpatient Clinic.

Can food allergy be cured? What are the future prospects?

Food allergies have become a significant heath burden as prevalence continues to rise, affecting 6%-13% of the global population. In the absence of drugs approved by regulatory agencies, the current standard of care remains avoidance of allergenic foods and management of acute allergic reactions with antihistamines and epinephrine autoinjectors. Allergen immunotherapy has been shown to increase the threshold of reactivity in the majority of food-allergic individuals. However, challenges include long treatment periods, high rates of adverse reactions, and lack of permanence of desensitization and established protocols. To address these limitations, adjunctive allergen-specific immunotherapy, vaccines, and non-allergen-specific therapies (eg, monoclonal antibodies) are being explored. The future of food allergy treatment is promising with a number of clinical trials in progress. Currently, although desensitization can be achieved for the majority of individuals with food allergy through immunotherapy, continued ingestion of allergen is needed for most individuals to maintain desensitization. Further understanding of the mechanisms of food allergy and identification of biomarkers to distinguish between temporary and permanent resolution of allergies is needed before a cure, where reactivity to the allergen is permanently lost enabling the individual to consume the allergen in any amount at any time, can be envisioned.

New Perspectives in Food Allergy

The improvement of the knowledge of the pathophysiological mechanisms underlying the tolerance and sensitization to food antigens has recently led to a radical change in the clinical approach to food allergies. Epidemiological studies show a global increase in the prevalence of food allergy all over the world and manifestations of food allergy appear increasingly frequent also in elderly subjects. Environmental and nutritional changes have partly changed the epidemiology of allergic reactions to foods and new food allergic syndromes have emerged in recent years. The deepening of the study of the intestinal microbiota has highlighted important mechanisms of immunological adaptation of the mucosal immune system to food antigens, leading to a revolution in the concept of immunological tolerance. As a consequence, new prevention models and innovative therapeutic strategies aimed at a personalized approach to the patient affected by food allergy are emerging. This review focuses on these new perspectives and their practical implications in the management of food allergy, providing an updated view of this complex pathology.

Recent developments and highlights in food allergy

The achievement of long-lasting, safe treatments for food allergy is dependent on the understanding of the immunological basis of food allergy. Accurate diagnosis is essential for management. In recent years, data from oral food challenges have revealed that routine allergy testing is poor at predicting clinical allergy for tree nuts, almonds in particular. More advanced antigen-based tests including component-resolved diagnostics and epitope reactivity may lead to more accurate diagnosis and selection of therapeutic intervention. Additional diagnostic accuracy may come from cellular tests such as the basophil activation test or mast cell approaches. In the context of clinical trials, cellular tests have revealed specific T-cell and B-cell populations that are more abundant in food-allergic individuals with distinct mechanistic features. Awareness of clinical markers, such as the ability to eat baked forms of milk and egg, continues to inform the understanding of natural tolerance development. Mouse models have allowed for investigation into multiple mechanisms of food allergy including modification of epithelial metabolism, and the induction of regulatory cell subsets and the microbiome. Increasing numbers of children who underwent food immunotherapy enlarged the body of evidence on mechanisms and predictors of treatment success. Experimental immunological markers in conjunction with clinical determinants such as lower age and lower initial specific IgE appear to be of benefit. More research on the optimal dose, preparation, and route of application integrating a high-level safety and efficacy is demanded. Alternatively, biologics blocking TSLP, IL-33, IL-4 and IL-13, or IgE may help to achieve that.

The clinical and immune outcomes after food allergen immunotherapy emphasizing the development of tolerance

PURPOSE OF REVIEW

The present review serves to outline the direction of food allergy immunotherapy research with an emphasis on clinical and immunologic outcomes. It helps to delineate sustained unresponsiveness achieved from food immunotherapy as the clinical outcome most similar to immune tolerance.

RECENT FINDINGS

We will discuss the difference between immune tolerance, desensitization, and sustained unresponsiveness in relation to food immunotherapy by discussing the clinical and immunologic changes which have been recently discovered.

SUMMARY

Research has recently shown that oral immunotherapy is most efficacious clinically at achieving desensitization to a food and sustained unresponsiveness.

Safety of Food Oral Immunotherapy: What We Know, and What We Need to Learn

Oral immunotherapy (OIT) for food allergy entails a risk of adverse reactions, including anaphylaxis. This safety concern is the major barrier for OIT to become a therapeutic option in clinical practice. The high heterogeneity in safety reporting of OIT studies prevents setting the safety profile accurately. An international consensus is needed to facilitate the analysis of large pooled clinical data with homogeneous safety reporting, that together with integrated omics, and patients/families' opinions, may help stratify the patients' risk and needs, and help developing safe(r) individualized care pathways. This will give OIT the right place in the food allergy therapy.

Oral Immunotherapy (OIT): A Personalized Medicine

Oral Immunotherapy (OIT), a promising allergen-specific approach in the management of Food Allergies (FA), is based on the administration of increasing doses of the culprit food until reaching a maintenance dose. Each step should be adapted to the patient, and OIT should be considered an individualized treatment. Recent studies focused on the standardization and identification of novel biomarkers in order to correlate endotypes with phenotypes in the field of FA.

Update on oral immunotherapy for egg allergy

Oral immunotherapy (OIT) is an emerging treatment of IgE-mediated egg allergy. In the past decade, a multitude of studies have assessed the potential for egg OIT to induce clinical desensitization. The following review will evaluate the efficacy and safety of this therapy as determined by randomized controlled, non-randomized controlled and uncontrolled trials. Recent studies using reduced allergenic egg products and anti-IgE assisted therapy to improve egg OIT safety will also be discussed. Recent advances in the mechanisms underlying food OIT suggest that certain immune parameters may be helpful in monitoring response to therapy, including egg OIT. Although, egg OIT is consistently shown to be effective with regards to clinical desensitization, fewer studies have looked at persistent tolerance or sustained unresponsiveness. Limited results of long-term follow-up trials suggest that this therapy may have disease-modifying effects. In general, the comparison of studies is complicated by major differences in study designs, OIT protocols and endpoints.

Oral and sublingual immunotherapy for egg allergy

BACKGROUND

Clinical egg allergy is a common food allergy. Current management relies upon strict allergen avoidance. Oral immunotherapy might be an optional treatment, through desensitization to egg allergen.

OBJECTIVES

To determine the efficacy and safety of oral and sublingual immunotherapy in children and adults with immunoglobulin E (IgE)-mediated egg allergy as compared to a placebo treatment or an avoidance strategy.

SEARCH METHODS

We searched 13 databases for journal articles, conference proceedings, theses and trials registers using a combination of subject headings and text words (last search 31 March 2017).

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing oral immunotherapy or sublingual immunotherapy administered by any protocol with placebo or an elimination diet. Participants were children or adults with clinical egg allergy.

DATA COLLECTION AND ANALYSIS

We retrieved 97 studies from the electronic searches. We selected studies, extracted data and assessed the methodological quality. We attempted to contact the study investigators to obtain the unpublished data, wherever possible. We used the I² statistic to assess statistical heterogeneity. We estimated a pooled risk ratio (RR) with 95% confidence interval (CI) for each outcome using a Mantel-Haenzel fixed-effect model if statistical heterogeneity was low (I² value less than 50%). We rated the quality of evidence for all outcomes using GRADE.

MAIN RESULTS

We included 10 RCTs that met our inclusion criteria, that involved a total of 439 children (oral immunotherapy 249; control intervention 190), aged 1 year to 18 years. Each study used a different oral immunotherapy protocol; none used sublingual immunotherapy. Three studies used placebo and seven used an egg avoidance diet as the control. Primary outcomes were: an increased amount of egg that can be ingested and tolerated without adverse events while receiving allergen-specific oral immunotherapy or sublingual immunotherapy, compared to control; and a complete recovery from egg allergy after completion of oral immunotherapy or sublingual immunotherapy, compared to control. Most children (82%) in the oral immunotherapy group could ingest a partial serving of egg (1 g to 7.5 g) compared to 10% of control group children (RR 7.48, 95% CI 4.91 to 11.38; RD 0.73, 95% CI 0.67 to 0.80). Fewer than half (45%) of children receiving oral immunotherapy were able to tolerate a full serving of egg compared to 10% of the control group (RR 4.25, 95% CI 2.77 to 6.53; RD 0.35, 95% CI 0.28 to 0.43). All 10 trials reported numbers of children with serious adverse events (SAEs) and numbers of children with mild-to-severe adverse events. SAEs requiring epinephrine/adrenaline presented in 21/249 (8.4%) of children in the oral immunotherapy group, and none in the control group. Mild-to-severe adverse events were frequent; 75% of children presented mild-to-severe adverse events during oral immunotherapy treatment versus 6.8% of the control group (RR 8.35, 95% CI 5.31 to 13.12). Of note, seven studies used an egg avoidance diet as the control. Adverse events occurred in 4.2% of children, which may relate to accidental ingestion of egg-containing food. Three studies used a placebo control with adverse events present in 2.6% of children. Overall, there was inconsistent methodological rigour in the trials. All studies enrolled small numbers of children and used different methods to provide oral immunotherapy. Eight included studies were judged to be at high risk of bias in at least one domain. Furthermore, the quality of evidence was judged to be low due to small numbers of participants and events, and possible biases.

AUTHORS' CONCLUSIONS

Frequent and increasing exposure to egg over one to two years in people who are allergic to egg builds tolerance, with almost everyone becoming more tolerant compared with a minority in the control group and almost half of people being totally tolerant of egg by the end of treatment compared with 1 in 10 people who avoid egg. However, nearly all who received treatment experienced adverse events, mainly allergy-related. We found that 1 in 12 children had serious allergic reactions requiring adrenaline, and some people gave up oral immunotherapy. It appears that oral immunotherapy for egg allergy is effective, but confidence in the trade-off between benefits and harms is low; because there was a small number of trials with few participants, and methodological problems with some trials.

Desensitization to a whole egg by rush oral immunotherapy improves the quality of life of guardians: A multicenter, randomized, parallel-group, delayed-start design study

BACKGROUND

Patients with food allergies and their families have a significantly reduced health-related quality of life (QOL).

METHODS

We performed a multicenter, randomized, parallel-group, delayed-start design study to clarify the efficacy and safety of rush oral immunotherapy (rOIT) and its impact on the participants' daily life and their guardians (UMIN000003943). Forty-five participants were randomly divided into an early-start group and a late-start group. The early-start group received rOIT for 3 months, while the late-start group continued the egg elimination diet (control). In the next stage, both groups received OIT until all participants had finished 12 months of maintenance OIT.

RESULTS

The ratio of the participants in whom an increase of the TD was achieved in the first stage was significantly higher in the early-start group (87.0%), than in the late-start group (22.7%). The QOL of the guardians in the early-start group significantly improved after the first stage (65.2%), in comparison to the late-start group (31.8%). During 12 months of rOIT, the serum ovomucoid-specific IgE levels, the percentage of CD203c⁺ basophils upon stimulation with egg white, and the wheal size to egg white were decreased, while the serum ovomucoid-specific IgG4 levels were increased. However, approximately 80% of the participants in the early-start group showed an allergic reaction during the first stage of the study, whereas none of the patients in the late-start group experienced an allergic reaction.

CONCLUSIONS

rOIT induced desensitization to egg and thus improved the QOL of guardians; however, the participants experienced frequent allergic reactions due to the treatment.

Novel immunotherapy and treatment modality for severe food allergies

PURPOSE OF REVIEW

In recent years, many studies on oral immunotherapy (OIT) have been conducted; however, few have focused on severe food allergies. The purpose of this review was to assess the efficacy and safety of oral immunotherapies for patients with severe food allergy.

RECENT FINDINGS

We reviewed multiple immunotherapy reports published within a few years or reports focusing on severe food allergies. We also investigated recent studies on OIT and novel food allergy management.

SUMMARY

Immunotherapies targeting low-dose antigen exposure and oral food challenges using low-dose target volumes may be safer than conventional OIT. It is necessary to consider which immunotherapy regimen is appropriate based on allergy severity of the patient.