Oral immunotherapy for treatment of egg allergy in children

Immunological Outcomes of Allergen-Specific Immunotherapy in Food Allergy

IgE-mediated food allergies are caused by adverse immunologic responses to food proteins. Allergic reactions may present locally in different tissues such as skin, gastrointestinal and respiratory tract and may result is systemic life-threatening reactions. During the last decades, the prevalence of food allergies has significantly increased throughout the world, and considerable efforts have been made to develop curative therapies. Food allergen immunotherapy is a promising therapeutic approach for food allergies that is based on the administration of increasing doses of culprit food extracts, or purified, and sometime modified food allergens. Different routes of administration for food allergen immunotherapy including oral, sublingual, epicutaneous and subcutaneous regimens are being evaluated. Although a wealth of data from clinical food allergen immunotherapy trials has been obtained, a lack of consistency in assessed clinical and immunological outcome measures presents a major hurdle for evaluating these new treatments. Coordinated efforts are needed to establish standardized outcome measures to be applied in food allergy immunotherapy studies, allowing for better harmonization of data and setting the standards for the future research. Several immunological parameters have been measured in food allergen immunotherapy, including allergen-specific immunoglobulin levels, basophil activation, cytokines, and other soluble biomarkers, T cell and B cell responses and skin prick tests. In this review we discuss different immunological parameters and assess their applicability as potential outcome measures for food allergen immunotherapy that may be included in such a standardized set of outcome measures.

Epicutaneously sensitized food-induced anaphylaxis is ameliorated with "oral tolerance" to antigen

Food allergy is an antigen-specific immunological adverse reaction after exposure to a given food. Multiple clinical studies showed that oral immunotherapy (OIT) is effective for the prevention and treatment for food allergy that is developed in infants and children. However, the effectiveness of OIT for epicutaneously sensitized food allergy remains unclear. Previously, we established a mouse model of epicutaneous-sensitized food allergy. In this model, systemic allergic reaction including intestinal and skin symptoms, such as anaphylaxis, was observed. We treated this model with OIT in two ways (OIT before sensitization or OIT during the sensitization phase) and evaluated the preventive effect of both methods. OIT before sensitization significantly ameliorated mast cell degranulation in sensitized skin, but there was no decrease in rectal temperatures or in mast cell degranulation in the jejunum. However, OIT administered during the sensitization phase significantly ameliorated the decrease in rectal temperature and mast cell degranulation in the skin and jejunum. OIT before sensitization increased the regulatory T cells in mesenteric lymph node (MLN), but not in the spleen, and it reduced antigen-specific IgG, but not IgE, production compared with the non-OIT control. However, OIT during sensitization caused a greater increase in regulatory T cells in both the MLN and spleen and reduced antigen-specific IgE and IgG generation compared with the non-OIT control group. Thus, OIT during the sensitization phase was effective for the prevention of epicutaneous-sensitized food allergy.

Oral Immunotherapy for Food Allergy-a US Regulatory Perspective

The recent approval of Palforzia for treatment of peanut allergy by the US Food and Drug Administration (USFDA) predicts that additional products for oral immunotherapy (OIT) are on the horizon. In this article, the authors review the legal framework by which the USFDA regulates products for OIT of food allergy and the clinical data that demonstrated that the safety and effectiveness profile of Palforzia supported approval and conclude with a discussion of oral food challenge (OFC) as a clinical endpoint to demonstrate safety and effectiveness of OIT products.

Induction of sustained unresponsiveness after egg oral immunotherapy compared to baked egg therapy in children with egg allergy

BACKGROUND

While desensitization and sustained unresponsiveness (SU) have been shown with egg oral immunotherapy (OIT), the benefits of baked egg (BE) therapy for egg allergy have not been well studied.

OBJECTIVES

This study sought to evaluate the safety and efficacy of BE ingestion compared with egg OIT in participants allergic to unbaked egg but tolerant to BE.

METHODS

Children who are BE-tolerant but unbaked egg reactive ages 3 to 16 years were randomized to 2 years of treatment with either BE or egg OIT. Double-blind, placebo-controlled food challenges were conducted after 1 and 2 years of treatment to assess for desensitization, and after 2 years of treatment followed by 8 to 10 weeks off of treatment to assess for SU. Mechanistic studies were conducted to assess for immune modulation. A cohort of participants who are BE-reactive underwent egg OIT and identical double-blind, placebo-controlled food challenges as a comparator group.

RESULTS

Fifty participants (median age 7.3 years) were randomized and initiated treatment. SU was achieved in 3 of 27 participants assigned to BE (11.1%) versus 10 of 23 participants assigned to egg OIT (43.5%) (P = .009). In the BE-reactive comparator group, 7 of 39 participants (17.9%) achieved SU. More participants who are BE-tolerant withdrew from BE versus from egg OIT (29.6% vs 13%). Dosing symptom frequency in participants who are BE-tolerant was similar with BE and egg OIT, but more frequent in participants who are BE-reactive. Egg white-specific IgE, skin testing, and basophil activation decreased similarly after BE and egg OIT.

CONCLUSIONS

Among children allergic to unbaked egg but tolerant to BE, those treated with egg OIT were significantly more likely to achieve SU than were children ingesting BE.

World allergy organization anaphylaxis guidance 2020

Anaphylaxis is the most severe clinical presentation of acute systemic allergic reactions. The occurrence of anaphylaxis has increased in recent years, and subsequently, there is a need to continue disseminating knowledge on the diagnosis and management, so every healthcare professional is prepared to deal with such emergencies. The rationale of this updated position document is the need to keep guidance aligned with the current state of the art of knowledge in anaphylaxis management. The World Allergy Organization (WAO) anaphylaxis guidelines were published in 2011, and the current guidance adopts their major indications, incorporating some novel changes. Intramuscular epinephrine (adrenaline) continues to be the first-line treatment for anaphylaxis. Nevertheless, its use remains suboptimal. After an anaphylaxis occurrence, patients should be referred to a specialist to assess the potential cause and to be educated on prevention of recurrences and self-management. The limited availability of epinephrine auto-injectors remains a major problem in many countries, as well as their affordability for some patients.

Slow low-dose oral immunotherapy: Threshold and immunological change

BACKGROUND

We examined the feasibility, efficacy and safety of slow low-dose oral immunotherapy (SLOIT) for egg, milk, wheat allergies, with accepted severity-stratified initial and maintenance doses.

METHODS

Children with food allergies defined by low-dose oral food challenges (LD-OFCs) to hen's egg (cumulative protein dose up to 983 mg, n = 133), cow's milk (287 mg, n = 50), and wheat (226 mg, n = 45) were recruited. Participants were divided into two groups [SLOIT and control (complete avoidance]) based on their preferences. Participants who selected SLOIT were instructed to take the safe dose daily, with monthly increases, aiming to increase the dose by 10 times in one year. The primary outcome was the proportion of participants who passed the LD-OFCs following 1 year of therapy.

RESULTS

The participants in SLOIT group ingested their antigen 92.9% of the therapy's day on average. The proportion of participants who passed LD-OFCs was 35.9% (61/170) in the SLOIT group and 8.7% (4/46) in the control group (P < .001); no large differences were observed among allergens. Among the subjects who failed LD-OFCs, the median change in the total dose in the LD-OFC was 235% (interquartile range: 100%-512%) in the SLOIT group and 100% (42%-235%) in the control group (P < .001). Provoked allergic symptoms were observed in only 0.58% (280/48,486) per programmed intake and approximately 50% of the SLOIT group did not experience any obvious allergic symptoms throughout therapy.

CONCLUSIONS

SLOIT showed significant feasibility, efficacy and safety, providing a promising option to manage patients with severe food allergies.

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.

Oral immunotherapy for peanut allergy: The con argument

Background

In some countries of the world, peanut allergy represents an important source of anaphylactic reactions. Traditionally treated with the avoidance of responsible allergens, this condition can also be targeted by oral peanut immunotherapy.

Methods

In this study, we review the beneficial and side effects of currently available forms of peanut oral immunotherapy (POIT). We report the discussions resulting from the publication of a meta-analysis that brought to light the downsides of oral immunotherapy for peanuts.

Results

In some clinical situations, the risk-benefit ratio can favor peanut oral immunotherapy over avoidance. In many other situations, this is not the case. The decision must be based on the values and preferences of clinicians and patients. Those not ready to accept serious adverse effects from POIT are likely to continue the elimination diet; those motivated to achieving desensitization, and prepared to accept serious adverse effects, may choose to undergo POIT.

Conclusions

Without being prejudiced against peanut oral immunotherapy, we indicate the possible evolution of treatment for this condition is in a rapidly evolving broader scenario. Among the future options, sublingual immunotherapy, parenteral immunotherapy with modified allergens, transcutaneous immunotherapy, and the use of biologics will become important options.

Study protocol of a multicentre, randomised, controlled trial evaluating the effectiveness of probiotic and peanut oral immunotherapy (PPOIT) in inducing desensitisation or tolerance in children with peanut allergy compared with oral immunotherapy (OIT) alone and with placebo (the PPOIT-003 study)

INTRODUCTION

Peanut allergy is the the most common cause of life-threatening food-induced anaphylaxis. There is currently no effective long-term treatment. There is a pressing need for definitive treatments that improve the quality of life and prevent fatalities. Allergen oral immunotherapy (OIT) is a promising approach, which is effective at inducing desensitisation; however, OIT has a limited ability to induce sustained unresponsiveness (SU). We have previously shown that a novel treatment comprising a combination of the probiotic Lactobacillus rhamnosus CGMCC 1.3724 with peanut OIT (Probiotic Peanut Oral ImmunoTherapy (PPOIT)) is highly effective at inducing SU, with benefit persisting to 4 years after treatment cessation in the majority of initial treatment responders. Here we describe the protocol for a Phase IIb multicentre, double-blind, randomised, controlled trial (PPOIT-003) with dual primary objectives to evaluate the effectiveness of PPOIT at inducing SU (assessed at 8 weeks after treatment cessation) compared with placebo treatment and peanut OIT alone, in children with peanut allergy.

METHODS AND ANALYSIS

200 children 1 to 10 years of age with current peanut allergy confirmed by failed double-blind placebo-controlled food challenge (DBPCFC) at study screening will be recruited from three tertiary paediatric hospitals in Australia. There are three intervention arms-PPOIT, peanut OIT alone or placebo. Interventions are administered once daily for 18 months. The dual primary outcomes are: (1) the proportion of children who attain 8-week SU in the PPOIT group versus placebo group and (2) the proportion of children who attain 8-week SU in the PPOIT group versus OIT group.

ETHICS AND DISSEMINATION

This study has been approved by the Human Research Ethics Committees at the Royal Children's Hospital (HREC 35246) and the Child and Adolescent Health Service (RGS 2543). Results will be published in peer-reviewed journals and disseminated via presentations at international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12616000322437.

Food allergy oral immunotherapy

Food allergy oral immunotherapy (OIT) has demonstrated efficacy in promoting clinically relevant immunomodulation that leads to desensitization (reduced reactivity while on OIT) in the majority of treated individuals; however, sustained unresponsiveness after OIT cessation for a specified interval has only been observed in a subset. The potential therapeutic benefits of OIT must be balanced with the risk for adverse events. These adverse events may range from self-limited or easily treated oropharyngeal, respiratory, or gastrointestinal symptoms to persistent abdominal symptoms that lead to cessation of therapy and to anaphylaxis. To date, the majority of studies have evaluated single-allergen OIT approaches; however, multi-allergen OIT has demonstrated favorable safety and efficacy outcomes, and is the subject of ongoing investigation. Recent U.S. Food and Drug Administration approval of the first licensed OIT product for peanut allergy challenges the long-standing paradigm of dietary food avoidance as the sole option for individuals with food allergy. Yet, the limitations of this "first-generation" treatment support the need for continued research and development of next-generation therapies to improve efficacy, minimize risk, and allow for broad applicability to both individuals with single-food allergy and those with multifood allergies. Optimizing future therapies will require developing novel approaches that maximize both efficacy and safety and/or tolerability outcomes, potentially through the combination with biologic therapies or adjuvants. Shared decision-making among patients, physicians, and parents and/or caregivers is critical to select optimal candidates for treatment with OIT by balancing the potential therapeutic benefit and possible risk reduction with a realistic consideration of OIT treatment burden and the risk of treatment-related adverse events.

Emerging Food Allergy Biomarkers

The management of food allergy is complicated by the lack of highly predictive biomarkers for diagnosis and prediction of disease course. The measurement of food-specific IgE is a useful tool together with clinical history but is an imprecise predictor of clinical reactivity. The gold standard for diagnosis and clinical research is a double-blind placebo-controlled food challenge. Improvement in our understanding of immune mechanisms of disease, development of high-throughput technologies, and advances in bioinformatics have yielded a number of promising new biomarkers of food allergy. In this review, we will discuss advances in immunoglobulin measurements, the utility of the basophil activation test, T-cell profiling, and the use of -omic technologies (transcriptome, epigenome, microbiome, and metabolome) as biomarker tools in food allergy.

Persistent, refractory, and biphasic anaphylaxis: A multidisciplinary Delphi study

BACKGROUND

The use of inconsistent definitions for anaphylaxis outcomes limits our understanding of the natural history and epidemiology of anaphylaxis, hindering clinical practice and research efforts.

OBJECTIVE

Our aim was to develop consensus definitions for clinically relevant anaphylaxis outcomes by utilizing a multidisciplinary group of clinical and research experts in anaphylaxis.

METHODS

Using Delphi methodology, we developed agenda topics and drafted questions to review during monthly conference calls. Through online surveys, a 19-member panel consisting of experts in allergy and/or immunology and emergency medicine rated their level of agreement with the appropriateness of statements on a scale of 1 to 9. A median value of 1.0 to 3.4 was considered inappropriate, a median value of 3.5 to 6.9 was considered uncertain, and a median value of 7.0 to 9.0 was considered appropriate. A disagreement index was then calculated, with values less than 1.0 categorized as "consensus reached." If consensus was not reached after the initial survey, subsequent surveys incorporating the aggregate de-identified responses from prior surveys were sent to panel members. This process was repeated until consensus was reached or 4 survey rounds had been completed, after which the question was categorized as "no consensus reached."

RESULTS

The panel developed outcome definitions for persistent, refractory, and biphasic anaphylaxis, as well as for persistent and biphasic nonanaphylactic reactions. There was also consensus among panel members regarding the need to develop an anaphylaxis severity grading system.

CONCLUSION

Dissemination and application of these definitions in clinical care and research will help standardize the terminology used to describe anaphylaxis outcomes and serve as the foundation for future research, including research aimed at development of an anaphylaxis severity grading system.

Old Dog New Tricks: PLGA Microparticles as an Adjuvant for Insulin Peptide Fragment-Induced Immune Tolerance against Type 1 Diabetes

Poly[lactic-co-(glycolic acid)] (PLGA) is arguably one of the most versatile synthetic copolymers used for biomedical applications. In vivo delivery of multiple substances including cells, pharmaceutical compounds, and antigens has been achieved by using PLGA-based micro-/nanoparticles although, presently, the exact biological impact of PLGA particles on the immune system remains controversial. Type 1 diabetes (T1D) is one subtype of diabetes characterized by the attack of immune cells against self-insulin-producing pancreatic islet cells. Considering the autoimmune etiology of T1D and the recent use of PLGA particles for eliciting desired immune responses in various aspects of immunotherapy, for the present study, a combination of Ins2_9-23 peptide (a known autoantigen of T1D) and PLGA microparticles was selected for T1D prevention assessment in nonobese diabetic (NOD) mice, a well-known animal model with spontaneous development of T1D. Thus, inoculation of PLGA microparticles + Ins2_9-23 completely prevented T1D development, significantly better than untreated controls and mice treated by either PLGA microparticles or Ins2_9-23 per se. Subsequent mechanistic investigation further revealed a facilitative role of PLGA microparticles in immune tolerance induction. In summary, our data demonstrate an adjuvant potential of PLGA microparticles in tolerance induction and immune remodulation for effective prevention of autoimmune diseases such as T1D.

Therapeutic perspectives in food allergy

BACKGROUND

In the last twenty years, several studies have been conducted in the search for new therapeutic strategies in patients with food allergy; in particular, after the failure of injection immunotherapy, three different routes of administration, oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT), have been tested. The aim of this manuscript is to review OIT, SLIT, and EPIT clinical trials on food allergies and to suggest advantages and limits of the different routes of immunotherapy administration.

MAIN BODY

Of the three different routes of immunotherapy used in the treatment of food allergy, OIT is, at present, the only one actually able to induce an increase in tolerance in the majority of patients. However, its use is affected by serious secondary effects, such as major abdominal symptoms and anaphylaxis. The combination with omalizumab reduces the percentage of serious side effects. There are not many studies with SLIT for food allergy, but they have nevertheless shown that it is possible to obtain an increase in tolerance; however, this increase is modest in comparison with that obtained by OIT. EPIT, performed through the diffusion of allergens on intact skin, is the most recent form of immunotherapy. Although there are many works on EPIT carried out in laboratory animals, only few clinical studies have been published in humans. EPIT, unlike OIT and SLIT, is not responsible for systemic secondary effects such as anaphylaxis and eosinophilic oesophagitis but only for local and mild effects in areas where the devices are applied. Moreover, EPIT is characterized by high patient adherence.

CONCLUSION

OIT seems to have a prevalent application in patients who do not report previous symptoms of systemic or gastroenteric anaphylaxis, while SLIT and EPIT, in particular, could be more preferentially used in patients with a risk of anaphylaxis.

Patient Characteristics and Risk Factors for Home Epinephrine-Treated Reactions During Oral Immunotherapy for Food Allergy

BACKGROUND

Oral immunotherapy (OIT) is effective in desensitizing food-allergic patients but adverse events limit its applicability.

OBJECTIVE

To identify risk factors for home epinephrine-treated reactions during the build-up phase of OIT.

METHODS

A retrospective cohort study of patients older than 3.7 years undergoing OIT for food allergy at Shamir Medical Center between April 2010 and March 2019. All patients with a final disposition of full desensitization, partial desensitization, or failure were analyzed. Risk factors and outcome of home epinephrine-treated reactions were examined.

RESULTS

A total of 1037 patients (mean age, 8.4 years) who underwent 1100 OIT treatments (milk, n = 710; peanut, n = 213; egg, n = 50; sesame, n = 57; and tree nuts, n = 70) reached a final disposition and were analyzed. Full desensitization was achieved in 763 (69.4%) treatments, partial desensitization in 219 (19.9%), and 118 (10.7%) failed. Epinephrine was administered to 121 patients (11.7%) during 10.8% of treatments. Milk OIT was a significant risk factor both for epinephrine-treated reactions (odds ratio, 2.15; 95% CI, 1.25-3.68) and for low rate of full desensitization following such reactions compared with nonmilk OIT (18.2% vs 73.9%, respectively; P < .0001). Risk factors during milk OIT included asthma, pre-OIT reaction severity, lower tolerated dose, and epinephrine-treated reactions during clinic updosing, whereas risk factors during nonmilk OIT were male sex and lower tolerated dose.

CONCLUSIONS

Milk OIT poses a significant risk for home epinephrine-treated reactions during OIT and for poor outcome following such reactions. Together with the additional risk factors described for both milk and nonmilk OIT, this information may assist in patient selection for treatment.

Food Allergies

Food allergy is 1 of the 4 manifestations of the "atopic march," along with eczema, allergic rhinitis, and asthma. Depending on the pathophysiologic immune mechanisms behind a food allergy, it can be classified as immunoglobulin E-mediated, non-immunoglobulin E-mediated, or mixed. The prevalence of food allergies has risen worldwide during the past few decades, becoming a significant global health concern. Patients experiencing food allergies and their caregivers are heavily burdened personally, socially, emotionally, and financially. The health-care system is also considerably affected. Pediatricians, as primary health-care providers, are often challenged with these patients, becoming the first-line for the recognition and management of food allergies. The purpose of this review is to provide a comprehensive summary of food allergies, including the most up-to-date information, recent guidelines, and recommendations.

Recent advances in mechanisms of food allergy and anaphylaxis

Food allergens are innocuous proteins that promote tolerogenic adaptive immune responses in healthy individuals yet in other individuals induce an allergic adaptive immune response characterized by the presence of antigen-specific immunoglobulin E and type-2 immune cells. The cellular and molecular processes that determine a tolerogenic versus non-tolerogenic immune response to dietary antigens are not fully elucidated. Recently, there have been advances in the identification of roles for microbial communities and anatomical sites of dietary antigen exposure and presentation that have provided new insights into the key regulatory steps in the tolerogenic versus non-tolerogenic decision-making processes. Herein, we will review and discuss recent findings in cellular and molecular processes underlying food sensitization and tolerance, immunological processes underlying severity of food-induced anaphylaxis, and insights obtained from immunotherapy trials.

Efficacy and safety of oral immunotherapy with AR101 in European children with a peanut allergy (ARTEMIS): a multicentre, double-blind, randomised, placebo-controlled phase 3 trial

BACKGROUND

Peanut allergy is the leading cause of food-related anaphylaxis. Current management options can negatively affect food allergy-related quality of life. We aimed to investigate the efficacy of an investigational oral biologic drug (AR101).

METHODS

The AR101 Trial in Europe Measuring Oral Immunotherapy Success in peanut-allergic children (ARTEMIS) trial was a multicentre, double-blind, randomised, placebo-controlled phase 3 trial done at 18 hospitals in Ireland, France, Germany, Italy, Spain, Sweden, and the UK. Children and adolescents with peanut allergy, aged 4-17 years, who developed dose-limiting symptoms to 300 mg or less peanut protein (equivalent to approximately one peanut kernel) during a double-blind placebo-controlled food challenge test at study entry were enrolled. Participants were randomly assigned (3:1) to receive daily doses of either AR101 oral immunotherapy (AR101 group) or a taste-masked placebo (placebo group). All participants, investigators, and care providers were masked to treatment allocation until the study was completed. Doses were increased every 2 weeks over 6 months until a dose of 300 mg was reached and maintained for 3 months. The primary endpoint was the proportion of participants in the intention-to-treat or safety population (defined as those participants who had been randomly assigned and had received at least one dose of the assigned drug) who could consume a single dose of 1000 mg (cumulative dose 2043 mg) peanut protein without developing dose-limiting allergic symptoms at an exit double-blind placebo-controlled food challenge after 9 months of treatment. Additional endpoints included safety (ie, the frequency and severity of adverse events) and changes in food allergy-related quality of life, assessed by use of age-appropriate Food Allergy Quality of Life Questionnaires (FAQLQs) and the Food Allergy Independent Measure (FAIM). The study is registered with ClinicalTrials.gov, NCT03201003, and is completed.

FINDINGS

Between June 12, 2017, and Feb 15, 2018, 227 patients were screened, of whom 175 were randomly assigned to the AR101 group (n=132) and the placebo group (n=43). All primary and secondary endpoints were met. 77 (58%) of 132 participants in the AR101 group tolerated 1000 mg peanut protein at the exit food challenge versus one (2%) of 43 participants in the placebo group (AR101-placebo treatment difference 56·0% [95% CI 44·1-65·2], p<0·0001). Adverse events were reported by almost all participants. The maximum severity of adverse events reported was mild or moderate for most participants who received AR101 (mild, 66 [50%] of 132 participants; moderate, 63 [48%]; and severe, one [1%]) or placebo (mild, 24 [56%] of 43 participants; moderate, 18 [42%]; severe, none). Participants aged 8-12 years in the AR101 group reported improvements that exceeded the minimum clinically important difference between the two groups across all FAQLQ domains. Additionally, participants in the AR101 group and their caregivers reported improvements that exceeded the minimum clinically important difference in FAIM domains related to the perceived likelihood and outcomes of a severe allergic reaction.

INTERPRETATION

AR101 oral immunotherapy treatment led to rapid desensitisation to peanut protein, with a predictable safety profile that improved with treatment, and an associated improvement in self-reported and caregiver-reported food allergy-related quality of life. These patient-oriented outcomes provide invaluable data to help physicians, patients, and caregivers make informed, shared decisions on the management of peanut allergy.

FUNDING

Aimmune Therapeutics.

A counseling video with pre- and posttesting and checklist for oral immunotherapy consent improves participant knowledge

BACKGROUND

The use of oral immunotherapy (OIT) for food allergies has been expanding in North America. Although families are interested in this therapeutic approach, misconceptions are common; therefore, education of these families is essential before obtaining informed consent.

OBJECTIVE

To improve parent and patient knowledge about OIT by investigating the use of a counseling video (CV) and checklist.

METHODS

This retrospective review was conducted in a pediatric outpatient clinic. After consultation and review of the information package, 467 parents and patients (>12 years old) performed pre- and posttests in conjunction with a CV during a checklist-based 2-hour counseling session for OIT.

RESULTS

The evaluation of pre- and posttest performance suggested an improvement in the ability of patients to answer relevant questions pertaining to OIT. This was statistically significant for all groups, including mothers, fathers, and children (P < .001). Mothers performed better than fathers and patients in mean number of correct responses in both pre- and posttest scores and in posttest scores after adjustment for pretest scores. Fathers performed better than patients in both pre- and posttest scores but not on posttest scores after adjustment for pretest scores. A checklist-based format resulted in 100% of all major topics being discussed in a 1-hour discussion. Reported satisfaction was high among the participants.

CONCLUSION

This is the first study to evaluate the use of a CV in conjunction with pre- and posttesting to educate families about the key principles of OIT. We suggest that as part of extensive counseling for OIT, an educational video is beneficial in a pediatric outpatient clinic.

Sublingual immunotherapy for food allergy and its future directions

Food allergy is an important medical problem with increasing prevalence throughout the world. Different approaches of food immunotherapy are being investigated including oral, epicutaneous and sublingual routes. Sublingual immunotherapy (SLIT) for food allergy involves placement of glycerinated allergen under the tongue daily to achieve allergen-specific desensitization. SLIT has been studied in the treatment of hazelnut, peach, apple, milk and peanut allergies with substantial focus on the treatment of peanut allergy. Phase II studies have shown SLIT for treatment of peanut allergy increases the tolerated dose of peanut by a substantial margin with fewer and less severe side effects than other modalities. This review discusses the mechanisms of SLIT, early studies of its use in food allergy and larger randomized controlled trials for treatment of peanut allergy. Future directions using the mechanisms involved in SLIT include oral mucosal immunotherapy for peanut allergy.

Japanese guidelines for food allergy 2020

Five years have passed since the Japanese Pediatric Guideline for Food Allergy (JPGFA) was first revised in 2011 from its original version. As many scientific papers related to food allergy have been published during the last 5 years, the second major revision of the JPGFA was carried out in 2016. In this guideline, food allergies are generally classified into four clinical types: (1) neonatal and infantile gastrointestinal allergy, (2) infantile atopic dermatitis associated with food allergy, (3) immediate-type of food allergy (urticaria, anaphylaxis, etc.), and (4) special forms of immediate-type of food allergy such as food-dependent exercise-induced anaphylaxis and oral allergy syndrome (OAS). Much of this guideline covers the immediate-type of food allergy that is seen during childhood to adolescence. Infantile atopic dermatitis associated with food allergy type is especially important as the onset of most food allergies occurs during infancy. We have discussed the neonatal and infantile gastrointestinal allergy and special forms of immediate type food allergy types separately. Diagnostic procedures are highlighted, such as probability curves and component-resolved diagnosis, including the recent advancement utilizing antigen-specific IgE. The oral food challenge using a stepwise approach is recommended to avoid complete elimination of causative foods. Although oral immunotherapy (OIT) has not been approved as a routine treatment by nationwide insurance, we included a chapter for OIT, focusing on efficacy and problems. Prevention of food allergy is currently the focus of interest, and many changes were made based on recent evidence. Finally, the contraindication between adrenaline and antipsychotic drugs in Japan was discussed among related medical societies, and we reached an agreement that the use of adrenaline can be allowed based on the physician's discretion. In conclusion, this guideline encourages physicians to follow the principle to let patients consume causative foods in any way and as early as possible.

Outcomes for clinical trials of food allergy treatments

OBJECTIVE

Food allergy is a common condition that can have a significant impact on the quality of life of affected individuals and their caregivers. Recent years have witnessed an increased effort to identify new treatments for food allergy. Here, we review the need to identify core outcomes for measurement in clinical trials of food allergy treatments.

DATA SOURCES

We reviewed the literature regarding core outcome set development, the important role that these play in prioritizing patient-relevant outcomes, and the potential for core outcomes to accelerate the path to product marketing by allowing prompt and reliable evidence synthesis after trial publication.

STUDY SELECTIONS

We reviewed recent clinical trials of food allergy treatments to understand which outcomes have previously been measured, and also reviewed available core outcome set initiatives for other allergic conditions to understand which other outcomes might be explored in future trials.

RESULTS

Clinical trials of food allergy treatments have largely focused on outcomes that are relevant to investigators and commercial investors, especially the threshold of reactivity and immunologic changes. Future trials should consider addressing patient-important outcomes and should report the experiences of both adult and child participants and their caregivers.

CONCLUSION

There is a pressing need for core outcome set development for food allergy treatment trials.

Production of allergen-specific immunotherapeutic agents for the treatment of food allergy

Allergen-specific immunotherapy (IT) is emerging as a viable avenue for the treatment of food allergies. Clinical trials currently investigate raw or slightly processed foods as therapeutic agents, as trials using food-grade agents can be performed without the strict regulations to which conventional drugs are subjected. However, this limits the ability of standardization and may affect clinical trial outcomes and reproducibility. Herein, we provide an overview of methods used in the production of immunotherapeutic agents for the treatment of food allergies, including processed foods, allergen extracts, recombinant allergens, and synthetic peptides, as well as the physical and chemical processes for the reduction of protein allergenicity. Commercial interests currently favor producing standardized drug-grade allergen extracts for therapeutic use, and clinical trials are ongoing. In the near future, recombinant production could replace purification strategies since it allows the manufacturing of pure, native allergens or sequence-modified allergens with reduced allergenicity. A recurring issue within this field is the inadequate reporting of production procedures, quality control, product physicochemical characteristics, allergenicity, and immunological properties. This information is of vital importance in assessing therapeutic standardization and clinical safety profile, which are central parameters for the development of future therapeutic agents.

Food allergy immunotherapy: Oral immunotherapy and epicutaneous immunotherapy

IgE-mediated food allergy remains a significant and growing problem across the globe. Of the various treatment modalities, oral immunotherapy (OIT) and epicutaneous immunotherapy (EPIT) have been the best studied. Across various studies of OIT for egg, milk, and peanut allergy, strong levels of desensitization have been shown. With egg and peanut OIT, a limited remission, or sustained unresponsiveness (SU), has further been demonstrated. These advances have been further validated by successful phase 2 and phase 3 studies of peanut OIT. EPIT, using daily administrations of a proprietary patch, demonstrated efficacy as well as safety and tolerability in parallel phase 2 studies; however, its phase 3 study did not meet its primary efficacy outcome. Despite its good track record of desensitization, the safety and tolerability of OIT has remained a question. EPIT, on the other hand, has proven safe and tolerable; however, the adequacy of its desensitization has remained to be determined. As OIT and EPIT continue their march toward regulatory review, optimizations for immunotherapy and novel therapies continue to be developed providing hope for food allergy patients everywhere.

Exercise-induced allergic reactions on desensitization to wheat after rush oral immunotherapy

BACKGROUND

The effect of oral immunotherapy (OIT) on wheat allergy is promising in terms of the potential to obtain desensitization; however, the frequency of exercise-induced allergic reactions on desensitization (EIARDs) and the associated risk factors remain to be determined.

METHODS

Twenty-five patients underwent rush OIT for wheat allergy, and 21 achieved the full-dose intake of wheat products (5 g of wheat protein). Exercise-provocation tests were repeatedly performed after the ingestion of a full-dose wheat product. The time-course of the levels of the specific IgEs (sIgE) to wheat extract, total gliadin, deamidated gliadin, recombinant gliadin components (α/β-, γ- and ω-5-), and glutenin (high and low molecular weight) components was analyzed using ImmunoCAP^® , ELISA, or IgE immunoblotting.

RESULTS

Fourteen patients (66.7%) were diagnosed as EIARD+, which remained 5 years after rush OIT in 11 patients (52.4%). There were no differences in the clinical backgrounds of the EIARD+ and EIARD- patients. However, EIARD+ patients showed significantly higher sIgE levels to all gliadin and glutenin components than EIARD- patients before OIT. The sIgE levels to each component decreased equally after 1 and 2 years of OIT. On IgE immunoblotting, sera from all patients reacted to the multiple gluten bands, and some reacted to the water-soluble bands. The intensity of all IgE-reactive bands also became equally lighter after OIT.

CONCLUSIONS

EIARDs were frequently observed and remained for a long period after successful OIT for wheat allergy. None of the specific wheat components were found to contribute to EIARDs.

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.

Mechanisms of allergen-specific immunotherapy for allergic rhinitis and food allergies

Allergen-specific immunotherapy (AIT) is currently the only potential treatment for allergies including allergic rhinitis (AR) and food allergies (FA) that can modify the underlying course of the diseases. Although AIT has been performed for over a century, the precise and detailed mechanism for AIT is still unclear. Previous clinical trials have reported that successful AIT induces the reinstatement of tolerance against the specific allergen. In this review, we aim to provide an updated summary of the knowledge on the underlying mechanisms of IgE-mediated AR and FA as well as the immunological changes observed after AIT and discuss on how better understanding of these can lead to possible identification of biomarkers and novel strategies for AIT.

Protocol for a double-blind, randomized controlled trial on the dose-related efficacy of omalizumab in multi-food oral immunotherapy

Background

Previous proof-of-concept studies have shown that a short course of omalizumab can safely accelerate the oral immunotherapy schedule for multiple allergens simultaneously. Considering the high cost of medication, the dose-related efficacy of omalizumab at decreasing the duration of oral immunotherapy up-dosing phase must be objectively quantified before cost–benefit analyses can be performed. The primary objective of this trial will be to compare the efficacy of 2 omalizumab dosages to placebo at decreasing time-to-maintenance dose during a symptom-driven multi-food OIT protocol.

Methods

A total of 90 participants aged 6 to 25 with multiple food allergies (3 or more) will be enrolled at four sites in Canada. Participants will be randomized to: (A) Omalizumab 8 mg/kg per month (n = 36); (B) Omalizumab 16 mg/kg per month (n = 36); or (C) Placebo (n = 18). Study drug will be administered at full dosage for 12 weeks, then progressively tapered at 50% dosage (8 mg/kg vs 4 mg/kg vs placebo) for 4 weeks and at 25% dosage (4 mg/kg vs 2 mg/kg vs placebo) for another 4 weeks. After a pre-treatment period of 8 weeks, participants will undergo an initial food escalation (IFE) to an OIT mix containing 3 allergens and start daily home dosing with biweekly increases until a target daily maintenance of 1500 mg protein is achieved. The amount escalated at each visit will vary based on treatment tolerance according to a standardized up-dosing algorithm. Participants will be followed for at least 12 months following the initial food escalation. The primary endpoint will be time from IFE to the target maintenance dose of 1500 mg protein. Time-to-event analytic methods, including the log-rank test, will be used to compare the 3 arms.

Discussion

This trial uses a novel pragmatic approach to compare OIT with omalizumab to OIT without omalizumab in a blinded manner, which allows to single out the effect of this anti-IgE medication on treatment effectiveness speed without the recourse to predetermined schedules. The innovative patient-centered up-dosing algorithm allows to maximise treatment effectiveness speed without compromising patient safety, regardless of whether the patient is on omalizumab or not. This study will also provide novel prospective data to inform on the optimal and most cost-effective dosage for this indication.

Trial registration ClinicalTrials.gov, NCT04045301, Registered 5 August 2019, https://clinicaltrials.gov/ct2/show/NCT04045301

A 5-year summary of real-life dietary egg consumption after completion of a 4-year egg powder oral immunotherapy (eOIT) protocol

The majority of children with sustained unresponsiveness after extended egg OIT are able to successfully introduce dietary egg. OIT outcome may be predictive of frequency, type (concentrated, baked), and quantity of egg ingested in the long term.

Intranasal nanoemulsion vaccine confers long-lasting immunomodulation and sustained unresponsiveness in a murine model of milk allergy

BACKGROUND

Immunotherapy for food allergy requires prolonged treatment protocols and, in most cases, does not lead to durable modulation of the allergic immune response. We have demonstrated an intranasal (IN) nanoemulsion adjuvant that redirects allergen-specific Th2 responses toward Th1 and Th17 immunity, and protects from allergen challenge after only 2-4 monthly administrations. Here, we investigate the ability of this technology to provide long-term modulation of allergy in a murine model of cow's milk allergy.

METHODS

Six weeks after sensitization to bovine casein, mice received four, monthly IN immunizations with nanoemulsion formulated with casein. Protection from casein challenge was assessed at 4 and 16 weeks after the final vaccine administration.

RESULTS

The NE vaccine significantly blunted the physiological responses to allergen challenge, and this effect persisted for at least 16 weeks. The protection from challenge was associated with the suppression of casein-specific Th2 immunity and induced Th1 and Th17 cytokines as well as induction of IL-10. Of interest, while immunized animals showed significantly decreased Th2 cytokine responses, cow's milk-specific IgE remained elevated in the serum at levels associated with reactivity in control sensitized animals. Protection was associated with suppressed mast cell activation and markedly reduced mast cell infiltration into the small intestine.

CONCLUSION

The sustained unresponsiveness of at least 16 weeks after vaccination suggests that the nanoemulsion vaccine alters the allergic phenotype in a persistent manner different from traditional desensitization, and this leads to long-term suppressive effects on allergic disease without eliminating serum IgE.

CSACI guidelines for the ethical, evidence-based and patient-oriented clinical practice of oral immunotherapy in IgE-mediated food allergy

Background

Oral immunotherapy (OIT) is an emerging approach to the treatment of patients with IgE-mediated food allergy and is in the process of transitioning to clinical practice.

Objective

To develop patient-oriented clinical practice guidelines on oral immunotherapy based on evidence and ethical imperatives for the provision of safe and efficient food allergy management.

Materials and methods

Recommendations were developed using a reflective patient-centered multicriteria approach including 22 criteria organized in five dimensions (clinical, populational, economic, organizational and sociopolitical). Data was obtained from: (1) a review of scientific and ethic literature; (2) consultations of allergists, other healthcare professionals (pediatricians, family physicians, nurses, registered dieticians, psychologists, peer supporters), patients and caregivers; and patient associations through structured consultative panels, interviews and on-line questionnaire; and (3) organizational and economic data from the milieu of care. All data was synthesized by criteria in a multicriteria deliberative guide that served as a platform for structured discussion and development of recommendations for each dimension, based on evidence, ethical imperatives and other considerations.

Results

The deliberative grid included 162 articles from the literature and media reviews and data from consultations involving 85 individuals. Thirty-eight (38) recommendations were made for the practice of oral immunotherapy for the treatment of IgE mediated food allergy, based on evidence and a diversity of ethical imperatives. All recommendations were aimed at fostering a context conducive to achieving objectives identified by patients and caregivers with food allergy. Notably, specific recommendations were developed to promote a culture of shared responsibility between patients and healthcare system, equity in access, patient empowerment, shared decision making and personalization of OIT protocols to reflect patients' needs. It also provides recommendations to optimize organization of care to generate capacity to meet demand according to patient choice, e.g. OIT or avoidance. These recommendations were made acknowledging the necessity of ensuring sustainability of the clinical offer in light of various economic considerations.

Conclusions

This innovative CPG methodology was guided by patients' perspectives, clinical evidence as well as ethical and other rationales. This allowed for the creation of a broad set of recommendations that chart optimal clinical practice and define the conditions required to bring about changes to food allergy care that will be sustainable, equitable and conducive to the well-being of all patients in need.

Basophil activation testing in occupational respiratory allergy to low molecular weight compounds

PURPOSE OF REVIEW

There is an unmet need for better immunological tests in cases of suspected occupational asthma to many workplace chemicals; here we consider the basophil activation test (BAT), a potential alternative to the detection of specific IgE antibodies.

RECENT FINDINGS

BAT is fairly widely used in general allergy services; and there is increasing experience of its use in the diagnosis of occupational allergy to low molecular weight agents and chemicals including wood dusts, persulphates, antibiotics and latex.

SUMMARY

There is potential for BAT to become a useful tool in the clinical consideration of occupational asthma and of its mechanisms, and even to take a place in a Bayesian-based diagnostic algorithm. Further development will only occur if specialist centres with appropriate facilities, and preferably in collaboration, contemplate its use.

Component-Resolved Diagnostic Study of Egg Allergy in Northern Chinese Children

BACKGROUND

Egg component-specific IgE can be useful to evaluate and diagnose egg allergy, but their prevalence and clinical significance remain unclear in the local population. Previous studies have led to contradictory results regarding the value of specific IgG and specific IgG4 in sensitization.

OBJECTIVE

We aimed to determine the level of specific IgE, IgG, and IgG4 antibodies to the major egg allergens in egg-allergic children.

METHODS

Children from 6 months to 10 years of age were recruited. Egg allergy was confirmed by either a strong clinical history or an increased egg white-sIgE level. Other allergies were diagnosed by reactivity to other allergens but without egg-related symptoms and history. The serum sIgE, sIgG, and sIgG4 levels to major egg allergenic components (Gal d 1, Gal d 2, Gal d 3, Gal d 4, and Gal d 5), sIgE level to egg white, and tIgE level were determined by light-initiated chemiluminescent assay (LICA), ELISA, or ImmunoCAP.

RESULTS

Egg-allergic children had significantly higher levels of sIgE, sIgG, and sIgG4 to egg components than nonallergic children. Gal d 2 was the predominant allergen, and Gal d 2 sIgE level correlated with the egg white-sIgE level. Ratios of sIgE/sIgG4 to egg components were highest before 1 year of age and dropped gradually in the first decade of life.

CONCLUSION

Patterns of sIgE to egg components could distinguish different forms of egg allergy. Ratios of sIgE/sIgG4 could be useful in predicting tolerance in egg-sensitive subjects, but this needs further evaluation and investigation using more accurate models.

Sustained successful peanut oral immunotherapy associated with low basophil activation and peanut-specific IgE

BACKGROUND

Oral immunotherapy (OIT) can successfully desensitize many peanut-allergic subjects, but clinical tolerance diminishes over time on discontinuation, or low-dose maintenance, of peanut. Therefore, to improve the efficacy and sustainability of such therapy, we sought to identify biomarkers and clinical tools that can predict therapeutic outcomes and monitor treatment responses.

OBJECTIVE

We evaluated whether basophil activation in whole blood, and plasma levels of peanut-specific immunoglobulins, are useful biomarkers for peanut OIT.

METHODS

We longitudinally measured, before, during, and after OIT, basophil activation in whole blood ex vivo in response to peanut stimulation, and peanut-specific IgE (sIgE) and peanut-specific IgG4 (sIgG4), in a large, single-site, double-blind, randomized, placebo-controlled, phase 2 peanut OIT study. We compared basophil responsiveness and peanut-specific immunoglobulins between those who were clinically reactive and those who were tolerant to peanut oral challenges.

RESULTS

Peanut OIT significantly decreased basophil activation, peanut sIgE, Ara h 1, Ara h 2, and Ara h 3 IgE levels, and sIgE/total IgE, but increased sIgG4/sIgE. Participants who became reactive to 4 g of peanut 13 weeks off active OIT exhibited higher peanut-induced basophil activation ex vivo and higher peanut sIgE levels and sIgE/total IgE, but lower sIgG4/sIgE. Notably, participants entering the study with low basophil responsiveness were more likely to achieve treatment success. Substantial suppression of basophil activation was required to maintain long-term clinical tolerance after peanut OIT.

CONCLUSIONS

Assessments of peanut-induced basophil activation and peanut-specific immunoglobulins can help to predict treatment outcomes, and to differentiate transient desensitization versus sustained unresponsiveness after OIT.

The impact of microRNAs on alterations of gene regulatory networks in allergic diseases

Allergic diseases including asthma are worldwide on the rise and contribute significantly to health expenditures. Allergic diseases are prototypic diseases with a strong gene by environment interaction component and epigenetic mechanisms might mediate the effects of the environment on the disease phenotype. MicroRNAs, small non-coding RNAs (miRNAs), regulate gene expression post-transcriptionally. Functional single-stranded miRNAs are generated in multiple steps of enzymatic processing from their precursors and mature miRNAs are included into the RNA-induced silencing complex (RISC). They imperfectly base-pair with the 3'UTR region of targeted genes leading to translational repression or mRNA decay. The cellular context and microenvironment as well the isoform of the mRNA control the dynamics and complexity of the regulatory circuits induced by miRNAs that regulate cell fate decisions and function. MiR-21, miR-146a/b and miR-155 are among the best understood miRNAs of the immune system and implicated in different diseases including allergic diseases. MiRNAs are implicated in the induction of the allergy reinforcing the Th2 phenotype (miR-19a, miR-24, miR-27), while other miRNAs promote regulatory T cells associated with allergen tolerance or unresponsiveness. In the current chapter we describe in detail the biogenesis and regulatory function of miRNAs and summarize current knowledge on miRNAs in allergic diseases and allergy relevant cell fate decisions focusing mainly on immune cells. Furthermore, we evoke the principles of regulatory loops and feedback mechanisms involving miRNAs on examples with relevance for allergic diseases. Finally, we show the potential of miRNAs and exosomes containing miRNAs present in several biological fluids that can be exploited with non-invasive procedures for diagnostic and potentially therapeutic purposes.

Evolution of Immune Responses in Food Immunotherapy

Food allergies are a growing public health concern affecting approximately 8% of children and 10% of adults in the United States. Several immunotherapy approaches are under active investigation, including oral immunotherapy, epicutaneous immunotherapy, and sublingual immunotherapy. Each of these approaches uses a similar strategy of administering small, increasing amounts of allergen to the allergic subject. Immunologic studies have described changes in the T-cell compartment, serum and salivary immunoglobulin profile, and mast cell and basophil degranulation status in response to allergens. This review highlights the immunologic changes induced by food allergen-specific immunotherapy and discusses future directions in this field.

New Developments in Non-allergen-specific Therapy for the Treatment of Food Allergy

PURPOSE OF REVIEW

The prevalence of food allergy is increasing. At the current time, there are no approved treatments for food allergy. Major limitations of immunotherapy are long treatment periods (months or years), frequent clinic visits, high costs, increased risk of adverse events during treatment, and lack of durability of desensitization. Additionally, it is allergen-specific, and in those allergic to multiple allergens, the length and cost of treatment are further increased. In this review, we summarize recent developments in novel non-allergen-specific treatments for food allergy.

RECENT FINDINGS

A number of monoclonal antibodies that block IgE or specific pro-allergenic cytokines or their receptors have shown promise in clinical trials for food allergy. The insight we have gained through the use of one drug for the treatment of an atopic disease is quickly being translated to other atopic diseases, including food allergy. The future for food allergy treatment with biologics looks bright.

Approach to Patients with Allergic Rhinitis: Testing and Treatment

This article evaluates the role of allergen immunotherapy (AIT) in the treatment of allergic rhinitis (AR). AIT has been shown to be effective in treating AR symptoms with resultant improvements in overall quality of life, comorbid illnesses, and medication requirements. Persistent clinical benefits have been shown years after AIT treatment discontinuation. AIT may prevent the progression of AR to asthma. AIT may more cost-effective than pharmacotherapy. Multiple individual studies and systematic reviews provide strong evidence for the clinical effectiveness of AIT in the treatment of AR. Cost-effectiveness and disease modification of AIT compared with standard drug treatment are additional advantages.

Are avoidance diets still warranted in children with atopic dermatitis?

Nearly 40% of children with moderate-to-severe atopic dermatitis (AD) have IgE-mediated food allergy (FA). This clinical observation has been extensively documented by experimental data linking skin inflammation in AD to FA, as well as by food challenges reproducing symptoms and avoidance diets improving AD. Although food avoidance may improve AD, avoidance diets do not cure AD, may even have detrimental effects such as progression to immediate-type allergy including anaphylactic reactions, and may significantly reduce the quality of life of the patient and the family. AD care should focus upon optimal medical management, rather than dietary elimination. Food allergy testing is primarily indicated when immediate-type allergic reactions are a concern. In recalcitrant AD, if food is being considered a possible chronic trigger, a limited panel of foods may be tested. An avoidance diet is only indicated in patients clearly identified as food allergic by an appropriate diagnostic food challenge, and after adequately informing the family of the limited benefits, and possible harms of an elimination diet.

Combined Effects of Lactobacillus rhamnosus and Egg Oral Immunotherapy in a Mouse Model of Egg Allergy

Purpose

Recent clinical trials have successfully used oral immunotherapy (OIT) to treat food allergies. Probiotics have immunomodulatory effects by balancing Th1/Th2 immunity and enhancing regulatory T-cell activity. In this study, we analyzed the effects of OIT, probiotics alone, and probiotics administered simultaneously with OIT in a mouse model of egg allergy.

Methods

C3H/HeJ mice were sensitized by intragastric administration of ovomucoid (OM) with cholera toxin. For the OIT regime, increasing doses of OM were administered orally to sensitized mice. Lactobacillus casei variety ramnosus (Lcr35) was also administered. The mice were divided into 4 groups: control (no OIT), OIT, Lcr35, and OIT plus Lcr35 (OIT + Lcr35). The effects of OIT and Lcr35 treatment were estimated based on the symptom score, rectal temperature, serum levels of OM-specific immunoglobulin (Ig)E, IgA, IgG1, and IgG2a immediately after and 2 weeks after ceasing treatment and histological staining of the small intestine.

Results

The severity of anaphylaxis decreased in all treatment groups. Simultaneous administration of Lcr35 and OIT decreased the severity of anaphylaxis compared to controls and the OIT group. The protective effects were sustained 2 weeks after ceasing treatment in all treatment groups. A significant decrease in OM-specific IgA, IgG1, and IgG2a levels was observed in both the OIT and OIT plus Lcr35 groups. However, a significant decrease in the OM-specific IgE level was observed only in OIT plus Lcr35 treated mice and was sustained 2 weeks after ceasing treatment. Mucin amounts in the small intestine decreased after OIT, OIT plus Lcr35, and Lcr35 treatment with the lowest in the OIT plus Lcr35 group.

Conclusions

Lcr35 treatment during OIT had some synergic effect for protection against anaphylaxis in a mice model of egg allergy. These findings should be confirmed in future animal studies including more detailed immunological profiles and human studies.

Immunotherapy and Oral Immunotherapy with Omalizumab for Food Allergies

Food allergy is potentially life-threatening and has a major impact on quality of life. Avoidance is currently the only approved therapy, and, although effective, avoidance diets can be difficult and may also put children at risk of nutritional deficiencies and impaired growth. At least 80% of milk and egg-allergic children are expected to achieve natural tolerance to these foods by adulthood, and 15–20% of peanut or tree nut-allergic individuals ‘outgrow’ their allergies. Effective therapies for food allergies are therefore highly desirable. There have been several immunotherapies for food allergy such as oral immunotherapy (OIT), sublingual immunotherapy (SLIT), epicutaneous immunotherapy (EPIT), and OIT combined with anti-IgE monoclonal antibodies (omalizumab [OMB]). However, efficacy and safety have only been demonstrated in one large Phase III trial for peanut allergies. Additionally, there have only been three randomised, controlled studies of OMB–OIT combination and these were low-powered, single-centre trials; therefore, evidence levels were low in these trials. Studies that included long-term follow-up observations and clinical tolerance are rare. Additionally, clinical tolerance is not well-defined and remains unknown. Therefore, several problems remain to be resolved, but hopefully OIT in combination with OMB will resolve these problems in the future. Although there are only three randomised, controlled trials of OMB–OIT, the combination therapy enabled high dose desensitisation for a short duration without any adverse events, resulting in the sustained unresponsiveness in IgE-related food allergy. It is speculated that this combination therapy will be the most effective immunotherapy in the future.

Regional Differences in Food Allergies

The prevalence of food allergies is increasing worldwide. To understand the regional specificities of food allergies and develop effective therapeutic interventions, extensive regional epidemiological studies are necessary. While data regarding incidence, prevalence, regional variation, and treatment in food allergies are available for western countries, such studies may not be available in many Asian countries. China accounts for almost 20% of the world's population and has a vast ethnic diversity, but large-scale meta-analyses of epidemiological studies of food allergy in China are lacking. A literature search revealed 22 publications on the prevalence of food allergy in Chinese populations. A review of these studies showed that the prevalence of food allergies in China is comparable to that in western countries, even though the Chinese diet is vastly different from that of the West and may vary even greatly within China, and finally, specific antigenic triggers of food allergy vary between China and the West and also within China. Current clinical management of food allergy in China includes allergen-specific immunotherapy, Chinese herbal medicine, acupuncture, and Western medicine. This study demonstrates an unmet need in China for a thorough investigation of the prevalence of food allergies in China, the specific foods involved, and characterization of the specific antigenic triggers of food allergy with respect to ethnicity, age, and diet in China.

Biomarkers in Food Allergy Immunotherapy

PURPOSE OF REVIEW

Investigational allergen immunotherapies (AITs) including oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) have proven to increase allergen thresholds required to elicit an allergic reaction in a majority of subjects. However, these studies lack consistent biomarkers to predict therapy outcomes. Here, we will review biomarkers that are currently being investigated for AIT.

RECENT FINDINGS

The mechanisms underlying the therapeutic benefit of AIT involve various cell types, including mast cells, basophils, T cells, and B cells. Skin prick and basophil activation tests assess effector cell sensitivity to allergen and are decreased in subjects on AIT. Allergen-specific IgE increases initially and decreases with continued therapy, while allergen-specific IgG and IgA increase throughout therapy. Allergen-induced regulatory T cells (Tregs) increase throughout therapy and were found to be associated with sustained unresponsiveness after OIT. Subjects on OIT and SLIT have decreased Th2 cytokine production during therapy. Although trends have been reported, a common limitation of these biomarkers is that none are able to reproducibly predict prognosis during AIT. Further studies are needed to expand the currently available biomarker repertoire to provide personalized approaches to AIT.

Emerging Food Allergy Treatments

Immunoglobulin E (IgE)-mediated food allergy affects up to 8% of the pediatric population and occurs when a person develops antibodies to specific food proteins resulting in immediate reaction upon ingestion of the food in question. Current treatment revolves around strict allergen avoidance and prompt treatment of systemic, anaphylactic reactions with injectable epinephrine. However, despite strict avoidance, unexpected reactions are a significant problem. Therefore, therapeutic options for treatment of food allergy are in high demand. This article focuses on emerging therapies including oral immunotherapy, sublingual immunotherapy, epicutaneous immunotherapy, and possible adjunct therapies for the treatment and desensitization of IgE-mediated food allergy. [Pediatr Ann. 2019;48(12):e468-e472.].