Improving the safety of oral immunotherapy for food allergy

Fatal food anaphylaxis in adults and children

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

Flex-IT! Applying "Platform Trials" Methodology to Immunotherapy for Food Allergy in Research and Clinical Practice

There is an increasing trend in the management of food allergy toward active treatment using allergen immunotherapy (AIT). Although AIT is efficacious, treatment-related adverse events are common, particularly with oral immunotherapy in those with high levels of allergen-specific IgE sensitization. In clinical practice, these adverse events inevitably create challenges: clinicians and patients routinely face decisions whether to alter the dose itself, the frequency of dosing, and the pace of escalation, or indeed discontinue AIT altogether. Flexibility is therefore needed to adapt treatment, particularly in clinical practice, so that participants are "treated-to-target." For example, this may entail a significant change in the dosing protocol or even switching from one route of administration to another in response to frequent adverse events. We refer to this approach as flexible immunotherapy. However, there is little evidence to inform clinicians as to what changes to treatment are most likely to result in treatment success. Classical clinical trials rely, by necessity, on relatively rigid updosing protocols. To provide an evidence base to optimize AIT, the food allergy community should adopt adaptive platform trials, where a "master protocol" facilitates more efficient evaluation, including longer-term outcomes of multiple interventions. Within a single clinical trial, participants are able to switch between different treatment arms; interventions can be added or dropped without compromising the integrity of the trial. Developing platform trials for food AIT may initially be costly, but they represent a significant opportunity to grow the evidence base (with respect to both treatment outcomes and biomarker discovery) at scale. In addition, they could help understand longitudinal disease trajectories that are difficult to study in clinical trials for food allergy due to the time needed to demonstrate changes in efficacy. Finally, their adoption would achieve greater collaboration and consistency in approaches to proactive management of food allergy in routine clinical practice. As a community, we need to actively pursue this with funders and established research collaborations to deliver the very best outcomes for our patients and their families.

Phase 1 trial supports safety and mechanism of action of peptide immunotherapy for peanut allergy

BACKGROUND

Food allergy is a leading cause of anaphylaxis worldwide. Allergen-specific immunotherapy is the only treatment shown to modify the natural history of allergic disease, but application to food allergy has been hindered by risk of severe allergic reactions and short-lived efficacy. Allergen-derived peptides could provide a solution. PVX108 comprises seven short peptides representing immunodominant T-cell epitopes of major peanut allergens for treatment of peanut allergy.

METHODS

Pre-clinical safety of PVX108 was assessed using ex vivo basophil activation tests (n = 185). Clinical safety and tolerability of single and repeat PVX108 doses were evaluated in a first-in-human, randomized, double-blind, placebo-controlled trial in peanut-allergic adults (46 active, 21 placebo). The repeat-dose cohort received six doses over 16 weeks with safety monitored to 21 weeks. Exploratory immunological analyses were performed at pre-dose, Week 21 and Month 18 after treatment.

RESULTS

PVX108 induced negligible activation of peanut-sensitised basophils. PVX108 was safe and well tolerated in peanut-allergic adults. There were no treatment-related hypersensitivity events or AEs of clinical concern. The only events occurring more frequently in active than placebo were mild injection site reactions. Exploratory immunological analyses revealed a decrease in the ratio of ST2+ Th2A:CCR6+ Th17-like cells within the peanut-reactive Th pool which strengthened following treatment.

CONCLUSION

This study supports the concept that PVX108 could provide a safe alternative to whole peanut immunotherapies and provides evidence of durable peanut-specific T-cell modulation. Translation of these findings to clinical efficacy in ongoing Phase 2 trials would provide important proof-of-concept for using peptides to treat food allergy.

Optimal period for achieving sustained unresponsiveness in peanut oral immunotherapy

Background

Oral immunotherapy (OIT) can help children with persistent food allergies achieve sustained unresponsiveness (SU). However, the optimal therapeutic period for obtaining SU remains unclear.

Objective

We aimed to retrospectively investigate the association between the OIT treatment period and achievement of SU.

Methods

We enrolled patients who received OIT for peanut allergy between January 1, 2018 and December 31, 2022. OIT comprised the build-up phase, maintenance phase, complete avoidance, and an oral food challenge (OFC) for confirming SU. The peanut dose in the OFC was gradually increased to 3,000 mg (peanut protein: 795 mg), which was subsequently maintained for ≥5 months. SU was defined as a negative response to 795 mg of peanut protein after ≥2 weeks of complete avoidance. We evaluated the therapeutic OIT period for achieving SU using Kaplan-Meier analysis.

Results

Forty-eight patients underwent peanut OIT. The starting age at OIT initiation was 8 (interquartile range [IQR], 7-10) years. Forty-one (85%) patients had a history of anaphylaxis. The median specific immunoglobulin E concentration to peanut and Ara h 2 at OIT initiation was 85.3 (IQR, 33.7-100) and 57.6 (IQR, 21.9-100) UA/mL, respectively. The median observational period was 2.1 (IQR, 1.6-3.0) person-years (PY). Thirty-four (71%) patients achieved SU, with the rate of SU achievement gradually increasing with the therapeutic period. The median period until SU achievement was 2.1 (95% confidence interval, 1.6-2.5) PY. The rate of SU achievement slowed down after 2.7 PY.

Conclusion

OIT for at least 2.7 PY can increase the rate of SU achievement. The protocol No. 3107.

Food Allergens: When Friends Become Foes-Caveats and Opportunities for Oral Immunotherapy Based on Deactivation Methods

Food allergies represent a serious health concern and, since the 1990s, they have risen gradually in high-income countries. Unfortunately, the problem is complex because genetic, epigenetic, and environmental factors may be collectively involved. Prevention and diagnoses have not yet evolved into efficacious therapies. Identification and control of allergens present in edible substances hold promise for multi-purpose biomedical approaches, including oral immunotherapy. This review highlights recent studies and methods to modify the otherwise innocuous native proteins in most subjects, and how oral treatments targeting immune responses could help cancel out the potential risks in hypersensitive individuals, especially children. We have focused on some physical methods that can easily be conducted, along with chemo-enzymatic modifications of allergens by means of peptides and phytochemicals in particular. The latter, accessible from naturally-occurring substances, provide an added value to hypoallergenic matrices employing vegetal wastes, a point where food chemistry meets sustainable goals as well.

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

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

Inhibition of pathologic immunoglobulin E in food allergy by EBF-2 and active compound berberine associated with immunometabolism regulation

Introduction

Food allergy is a significant public health problem with limited treatment options. As Food Allergy Herbal Formula 2 (FAHF-2) showed potential as a food allergy treatment, we further developed a purified version named EBF-2 and identified active compounds. We investigated the mechanisms of EBF-2 on IgE-mediated peanut (PN) allergy and its active compound, berberine, on IgE production.

Methods

IgE plasma cell line U266 cells were cultured with EBF-2 and FAHF-2, and their effects on IgE production were compared. EBF-2 was evaluated in a murine PN allergy model for its effect on PN-specific IgE production, number of IgE⁺ plasma cells, and PN anaphylaxis. Effects of berberine on IgE production, the expression of transcription factors, and mitochondrial glucose metabolism in U266 cells were evaluated.

Results

EBF-2 dose-dependently suppressed IgE production and was over 16 times more potent than FAHF-2 in IgE suppression in U266 cells. EBF-2 significantly suppressed PN-specific IgE production (70%, p<0.001) and the number of IgE-producing plasma cells in PN allergic mice, accompanied by 100% inhibition of PN-induced anaphylaxis and plasma histamine release (p<0.001) without affecting IgG1 or IgG2a production. Berberine markedly suppressed IgE production, which was associated with suppression of XBP1, BLIMP1, and STAT6 transcription factors and a reduced rate of mitochondrial oxidation in an IgE-producing plasma cell line.

Conclusions

EBF-2 and its active compound berberine are potent IgE suppressors, associated with cellular regulation of immunometabolism on IgE plasma cells, and may be a potential therapy for IgE-mediated food allergy and other allergic disorders.

Food Allergy and Eosinophilic Gastrointestinal Diseases-The Next 10 Years

The first report of food allergy desensitization was in 1908, at least a few years before the first published description of a diagnostic test for food allergy. It has taken almost 100 years for food allergy to move from passive management of avoidance to a more proactive approach including prevention and treatment. In parallel, this has been matched by recognition of eosinophil gastrointestinal diseases, which were first described in the 1980s (although eosinophilic esophagitis was itself described in 1978). As we celebrate 10 years of The Journal of Allergy and Clinical Immunology: In Practice, we take the opportunity to look into the future and speculate how our practice may develop over the next decade.

Information needs of patients considering oral immunotherapy for food allergy

While the historic management of food allergy includes avoidance strategies and allergic reaction treatment, oral immunotherapy (OIT) approaches have become more commonly integrated into therapeutic approaches. International guidelines, phase 3 trials and real-world experience have supported the implementation of this procedure. However, OIT is an elective, rarely curative procedure with inherent risks that necessitates an increased degree of health literacy for the patients and families. Families assume the responsibility of amateur healthcare providers to ensure the daily safe administration of the allergenic food. As such, it is incumbent upon physicians to ensure that families are prepared for this role. A thorough educational and shared decision-making approach is necessary during the counselling and consent process to adequately inform the families. Educated discussion about the efficacy and patient-centred effectiveness, therapeutic alternatives and family goals is required to align physician and patient expectations. A frank discussion about the struggles, practical challenges, risks and contraindications can help to develop an understanding of the risk mitigation strategies employed to maintain safety. Physicians should develop a proactive approach to educate families about this, at times, burdensome procedure. This educational approach should encourage ongoing support starting prior to consent through the maintenance visits. By preparing families for their unique management role, physicians can help ensure the safe and successful integration of OIT into the therapeutic offering for the management of food allergies.

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

Background

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

Methods

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

Results

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

Conclusions

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

Immunological changes during desensitization with cow's milk: how differ from natural tolerance or nonallergic state?

BACKGROUND

Oral immunotherapy(OIT) is a novel allergen-specific treatment for food allergies.

OBJECTIVE

To investigate the effect of OIT on blocking antibodies, T cell regulation, and cytokine response during IgE-mediated cow's milk allergy(CMA) treatment.

METHODS

Fifty-seven children with Ig-E-mediated CMA who were followed in pediatric allergy outpatient clinic and 18 healthy children were included.The children were evaluated in four groups: OIT group, elimination group (patients receiving dairy elimination diet), tolerance group(patients who developed tolerance), healthy control group. Milk-specific IgE, IgG4, and IgA levels, cow's milk induration diameters in skin prick test, CD4+CD25+FoxP3+Treg cell percentages, mRNA expressions, and IL-10,TGF-β,IL-2,IL-4,IL-13 cytokine levels were compared between the groups.

RESULTS

The mean age of the patients was 42.6±39(6-201) months, 63.6%(n=49) of patients were girls. We observed an increase in total IgE levels(p=0.02) and a decrease in cow's-milk sIgE (p=0.08,NS), specific-IgA(p<0.01), and IgG4(p<0.01) levels at 2 months after the maintenance phase of OIT. In addition, the immune response after OIT treatment, which had a 100% clinical success rate, was notable for similar CD4+CD25+FoxP3+cell percentages(p=0.6), and increased IL-10(p=0.04) levels and increased but statistically nonsignificant TGF-β levels(p=0.17) compared with those before treatment.FoxP3 mRNA expression was similar to that of patients who developed natural tolerance. Pre-treatment and post-treatment FoxP3 mRNA-FoxP3 flow cytometric expressions were positively correlated with TGF-β concentrations in the OIT group.

CONCLUSION

A successful immune response to OIT was shown, possibly through the blockage of IgE-mediated allergen presentation by blocking antibodies, marked IL-10 cytokine response, and TGF-β response.FoxP3 mRNA expression was similar to the natural tolerance mechanism, but more studies are needed.

Risk factors for discontinuing oral immunotherapy in children with persistent cow milk allergy

Background

There are no universally accepted criteria for discontinuing milk oral immunotherapy (MOIT) in patients with persistent cow milk allergy (CMA) and little data are available on predictive risk factors for dropping out from oral immunotherapy (OIT), due to allergic reactions or other reasons.

Methods

We retrospectively reviewed clinical records of patients with persistent severe CMA undergoing MOIT in a tertiary care center hospital to investigate risk factors associated with discontinuation of OIT. Persistent and severe allergy was defined as the history of systemic reactions and any milk protein‐specific IgE level >85 kU/ml. All patients were first admitted for an in‐hospital rush phase eventually followed by an at‐home dose increase. We evaluated the effect of various factors on two primary outcomes: the highest dose of milk ingested during the in‐hospital rush phase and during the home OIT phase.

Results

We identified 391 patients, of whom 131 met the inclusion criteria for the retrospective study, 54 females and 77 males. Data of the home OIT phase were available for 104 patients (27%).

Regarding the home OIT outcome, an association for having a cow milk avoiding diet was found with reaching a dose below 10 ml during the in‐hospital rush phase (relative risks [RR]: 2.33, confidence interval [CI]: 0.85; 6.42), an age above than 10 years from the time of admission (RR: 3.29, CI: 0.85; 12.73), and a higher total number of reactions occurred during the hospitalization (RR: 1.54, CI: 1.02; 2.32), whereas the presence of respiratory reactions with wheezing (RR: 1.93, CI: 0.49; 7.61) and an IM adrenaline use was related to a higher risk of having an OIT still in progress (RR: 5.47, CI: 0.33; 7.73).

Conclusions

In this cohort of children with persistent CMA undergoing OIT who presented with respiratory reactions with wheezing, the development of anaphylaxis with the need for IM adrenaline, and age above 10 years were predictors of poor long‐term outcome.

This study shows that wheezing reactions during the in‐hospital phase admission, discharge with a dose below 10 ml, use of IM epinephrine, and older age (over 10 years) were all risk factors for OIT discontinuation.

The provided phenotype of patients with a severe milk allergy who are more likely to fail OIT can help pediatricians to provide to their parents the elements to properly decide the most appropriate approach.

Oral immunotherapy for food allergy in children: is it worth it?

INTRODUCTION

Oral immunotherapy (OIT) is effective at inducing desensitization in food-allergic individuals, and is a valid therapeutic option for those allergic to peanut, cow's milk and egg. However, there is a high rate of dose-related adverse events, and at least one fatality to OIT has been reported.

AREAS COVERED

We provide an update on the broader framework of issues which will impact on the availability and uptake of OIT.

EXPERT OPINION

The need for standardized products remains controversial. A licensed product exists for peanut-OIT, but OIT can also be safely achieved using peanut-containing foods at much lower cost. For other allergens, OIT can only be done with non-pharma products - something which has been done safely for over 2 decades. There is a need to develop personalized protocols for OIT, particularly for the 20% of patients unable to tolerate standard OIT. Cost-effectiveness is dependent on improved quality of life, but evidence for this is currently lacking, and is a key evidence gap. OIT is likely to be cost-effective, particularly if noncommercial products are used. There may be a trade-off: in patients with lower reaction thresholds, a commercial product may be needed for initial updosing, until a level of desensitization is achieved when they can be switched to natural food products.

Food immunotherapy practice: Nation differences across Europe, the FIND project

BACKGROUND

Food allergen immunotherapy (FA-AIT) practice is known to vary globally. This project aims to identify and characterize European centres performing FA-AIT.

METHODS

An EAACI task force conducted an online survey to gather relevant information regarding FA-AIT practice and setting-specific resources after reviewing the published literature and congress abstracts throughout Europe.

RESULTS

We identified 102 FA-AIT centres in 18 countries; only Spain (n = 39) and France (n = 16) had ≥10 such centres. Overall, most facilities were hospital-based (77.5%), publicly funded (80.4%) and delivered FA-AIT as routine clinical care (80.4%). On average, departments had 3 allergists/paediatric allergists and 2 nurses. Surveyed centres had provided FA-AIT for a median of 9 years [1-24] to a median of 105 [5-2415] patients. The estimated total number of treated patients was 24875, of whom 41.3% received AIT for milk, 34.2% egg, 12.8% peanut and 11.7% other foods. Anaphylaxis to AIT doses requiring over 4-6 h of observation was reported by 70.6% of centres, ICU admissions by 10.8% and eosinophilic esophagitis by 45.1%. Quality of life and sustained unresponsiveness were evaluated in 20.6% and 54.9% of centres, respectively. The main contraindications for food AIT were severe asthma (57%-63%), eosinophilic esophagitis (56%-48%) and age below 5 years (47%-41%).

CONCLUSIONS

In Europe, FA-AIT is provided mostly in clinical practice. Significant variation is seen in the number of centres per country, facility characteristics and inclusion/exclusion criteria, and in certain aspects of protocols. Potential inequality in access to AIT has been identified as well as the need for education and guidance for treatment standardization.

Oral Immunotherapy for Food-Allergic Children: A Pro-Con Debate

The prevalence of food allergy has increased in recent years, especially in children. Allergen avoidance, and drugs in case of an allergic reaction, remains the standard of care in food allergy. Nevertheless, increasing attention has been given to the possibility to treat food allergy, through immunotherapy, particularly oral immunotherapy (OIT). Several OIT protocols and clinical trials have been published. Most of them focus on children allergic to milk, egg, or peanut, although recent studies developed protocols for other foods, such as wheat and different nuts. OIT efficacy in randomized controlled trials is usually evaluated as the possibility for patients to achieve desensitization through the consumption of an increasing amount of a food allergen, while the issue of a possible long-term sustained unresponsiveness has not been completely addressed. Here, we evaluated current pediatric OIT knowledge, focusing on the results of clinical trials and current guidelines. Specifically, we wanted to highlight what is known in terms of OIT efficacy and effectiveness, safety, and impact on quality of life. For each aspect, we reported the pros and the cons, inferable from published literature. In conclusion, even though many protocols, reviews and meta-analysis have been published on this topic, pediatric OIT remains a controversial therapy and no definitive generalized conclusion may be drawn so far. It should be an option provided by specialized teams, when both patients and their families are prone to adhere to the proposed protocol. Efficacy, long-term effectiveness, possible role of adjuvant therapies, risk of severe reactions including anaphylaxis or eosinophilic esophagitis, and impact on the quality of life of both children and caregivers are all aspects that should be discussed before starting OIT. Future studies are needed to provide firm clinical and scientific evidence, which should also consider patient reported outcomes.

The Risk Reduction of Accidental Exposure-Related Systemic Allergic Reactions Extrapolated Based on Food Challenge Data After 1 Year of Peanut Oral Immunotherapy

Introduction

The phase 3 trial PALISADE, comparing peanut (Arachis hypogaea) allergen powder-dnfp (PTAH) oral immunotherapy versus placebo in peanut-allergic children, reported that a significantly higher percentage of PTAH-treated participants tolerated higher doses of peanut protein after 1 year of treatment. This study used PALISADE data to estimate the reduction in the risk of systemic allergic reaction (SAR) after accidental exposure following 1 year of PTAH treatment.

Methods

Participants (aged 4–17 years) enrolled in PALISADE were included. Parametric interval-censoring survival analysis with the maximum likelihood estimation was used to construct a real-world distribution of peanut protein exposure using lifetime SAR history and highest tolerated dose (HTD) from a double-blind, placebo-controlled food challenge conducted at baseline. The SAR risk reduction was extrapolated using the exposure distribution and the HTD were collected at baseline and trial exit for PTAH- and placebo-treated participants.

Results

Assuming a maximum peanut protein intake of 1500 mg, participants were estimated to have < 1% probability of ingesting > 0.01 mg during daily life. The mean annual SAR risk at trial entry was 9.25–9.98%. At trial exit, the relative SAR risk reduction following accidental exposure was 94.9% for PTAH versus 6.4% for placebo. For PTAH-treated participants with exit HTD of 600 or 1000 mg without dose-limiting symptoms, the SAR risk reduction increased to 97.2%. The result was consistent in the sensitivity analysis across different parametric distributions.

Conclusion

Oral immunotherapy with PTAH is expected to result in a substantially greater reduction in risk of SAR following accidental exposure compared to placebo among children with peanut allergy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01843-2.

Protocols for Managing Food Allergies in Elementary and Secondary Schools

The prevalence of food allergies is on the rise; nearly 8% of children worldwide are affected. The most common allergens-milk, eggs, peanuts, tree nuts, shellfish, fish, and wheat-account for 90% of serious allergic reactions. A literature review of online databases in CINAHL, PubMed Central, Education Resources Information Center (ERIC), Google Scholar, Health Resource Center Academic, and archival searching was performed to identify evidenced-based practices for managing food allergies in schools. There is no cure for food allergies. The current management standard is to avoid the allergen, treat a mild reaction with antihistamine and observation, and treat anaphylaxis with an intramuscular injection of epinephrine. Due to COVID-19 social distancing recommendations, food consumption in schools has moved from cafeterias and lunchrooms into classrooms and other spaces. This in turn necessitates strict adherence to hand washing and disinfecting all surfaces that come in contact with food. Managing food allergies in schools requires cooperation among school administrators, nurses, teachers, staff, families, and health care providers. Resources for managing food allergies in schools are presented offering information for parents, school administrators, nurses, teachers, and staff for planning and implementing strategies for preventing and reducing allergic reactions and treating life-threatening food allergy reactions.

Mechanisms of oral immunotherapy

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

Quality of life of children aged 8-12 years undergoing food allergy oral immunotherapy: Child and parent perspective

BACKGROUND

Oral immunotherapy (OIT) for food allergy improves the quality of life (QOL) of children from parental perspective but little is known about the child perception.

METHODS

The Food Allergy Quality of Life Questionnaire-Child Form (FAQLQ-CF) was administered to children aged 8-12 years, and the FAQLQ-Parent Form (FAQLQ-PF) was administered to their parents at the start of OIT for milk, egg, peanut, sesame, or tree nuts, at the end of up-dosing, and after 6 months of follow-up. Food-allergic children not undergoing OIT served as controls. Children QOL scores were compared to their parents.

RESULTS

The total FAQLQ-CF score of 103 children undergoing OIT improved significantly from start of OIT (median (IQR); 4.8, 3.8-5.7) to end of up-dosing (3.9, 3-5.2) (P < .001). A greater improvement was noted in the 56 children who reached a follow-up visit, from 5.0 (3.7-5.8) at OIT start to 3.1 (1.8-5.0) on follow-up, (P < .001). In contrast, FAQLQ-CF scores of control patients improved mildly and nonsignificantly between the two time points from 5.3 (4.3-5.7) to 4.8 (3.6-6.0), (P = .13). The improvement in the total FAQLQ-CF scores from OIT start to follow-up was significantly greater compared to the change in control patients during observation (P = .015). Parents reported better QOL scores compared to their children at all stages of OIT (start 4.0, 3.2-5, P = .004; end of up-dosing 2.9, 1.9-4.7, P = .04; follow-up 2.2, 1.6-3.6, P = .003).

CONCLUSIONS

QOL of food-allergic children undergoing OIT improves significantly compared to controls. Parents perceive QOL to be better than the perception of the children.

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.

Food Allergy Insights: A Changing Landscape

The panorama of food allergies (FA) has changed profoundly in recent years. In light of recent advances in knowledge of pathogenetic mechanisms and a greater attention to the multifaceted range of possible clinical manifestations, there is a need for a critical review of past classifications. Changes in nutrition, environment and lifestyles around the world are modifying the global FA epidemiology and new FA phenotypes are also emerging. Furthermore, both biotechnological advances in this field and recent personalized therapies have improved the diagnostic and therapeutic approach to FA. Consequently, both the prevention and clinical management of FA are rapidly changing and new therapeutic strategies are emerging, even revolutionizing the current medical practice. Given the significant increase in the prevalence of FA in recent years, the objective of this review is to provide an updated and complete overview of current knowledge in its etiopathogenesis, diagnostics and therapy, useful not only for a better understanding of this frequent and complex pathology but also for practical guidance in its clinical management.

Immunoglobulin E (IgE)-Mediated Food Allergy in Children: Epidemiology, Pathogenesis, Diagnosis, Prevention, and Management

A food allergy is an immunoglobulin E (IgE)-mediated hypersensitive reaction to food, which consists in the appearance of allergic symptoms; it can vary from common urticaria to even fatal anaphylaxis. The prevalence of food allergies has been increasing in the past twenty years and it represents a major public health problem in industrialized countries. The mechanism that leads to food allergies is the lack of immunologic and clinical tolerance to food allergens. The diagnosis of IgE-mediated food allergies is based on the combined use of a detailed medical history, in-vivo, and in-vitro research of specific IgE, the elimination diet, and the double-blind placebo-controlled food challenge. The only currently available treatment for allergies is the strict elimination diet. This type of attitude, which we could define as “passive”, does not overcome the risk of accidental reactions due to involuntary intake of the culprit food. For food allergy management, an “active” approach is urgently needed, such as specific allergen immunotherapy, which is currently under development and only used for research purposes. This article aims to give an updated review of IgE-mediated food allergies in pediatric populations in terms of epidemiology, pathogenesis, prevention, diagnosis, and management.

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.

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.

Network-Based Selection of Candidate Markers and Assays to Assess the Impact of Oral Immune Interventions on Gut Functions

To assess the safety and efficacy of oral immune interventions, it is important and required by regulation to assess the impact of those interventions not only on the immune system, but also on other organs such as the gut as the porte d'entrée. Despite clear indications that the immune system interacts with several physiological functions of the gut, it is still unknown which pathways and molecules are crucial to assessing the impact of nutritional immune interventions on gut functioning. Here we used a network-based systems biology approach to clarify the molecular relationships between immune system and gut functioning and to identify crucial biomarkers to assess effects on gut functions upon nutritional immune interventions. First, the different gut functionalities were categorized based on literature and EFSA guidance documents. Moreover, an overview of the current assays and methods to measure gut function was generated. Secondly, gut-function related biological processes and adverse events were selected and subsequently linked to the physiological functions of the GI tract. Thirdly, database terms and annotations from the Gene ontology database and the Comparative Toxicogenomics Database (CTD) related to the previously selected gut-function related processes were selected. Next, database terms and annotations were used to identify the pathways and genes involved in those gut functionalities. In parallel, information from CTD was used to identify immune disease related genes. The resulting lists of both gut and immune function genes showed an overlap of 753 genes out of 1,296 gut-function related genes indicating the close gut-immune relationship. Using bioinformatics enrichment tools DAVID and Panther, the identified gut-immune markers were predicted to be involved in motility, barrier function, the digestion and absorption of vitamins and fat, regulation of the digestive system and gastric acid, and protection from injurious or allergenic material. Concluding, here we provide a promising systems biology approach to identify genes that help to clarify the relationships between immune system and gut functioning, with the aim to identify candidate biomarkers to monitor nutritional immune intervention assays for safety and efficacy in the general population. This knowledge helps to optimize future study designs to predict effects of nutritional immune intervention on gut functionalities.

Food allergy-From food avoidance to active treatment

The prevalence of food allergy (FA) has increased too rapidly, possibly due to environmental factors. The guidelines recommend strict allergen avoidance, but FA is still the main cause of anaphylaxis in all age groups. Immunotherapy is the only treatment able to change the course of allergic disease, and oral immunotherapy (OIT) is the more effective route in FA. However, it carries the risk of adverse reactions, including anaphylaxis. To improve OIT safety, adjuvant therapy with the immunoglobulin E (IgE) monoclonal antibody omalizumab has been extensively used. Results suggest particular benefit in patients with high risk of fatal anaphylaxis. An alternative approach is to use omalizumab instead of OIT to prevent severe allergic reactions upon accidental exposure. This paper reviews current evidence regarding IgE-mediated FA, focusing on natural tolerance and food sensitization acquisition, and on avoidance measures and their limitations.

Oral immunotherapy with peach juice in patients allergic to LTPs

Introduction

To assess the safety and efficacy of an oral immunotherapy regimen in patients with allergy to lipid transfer proteins (LTPs).

Materials and methods

Prospective study of 24 patients allergic to LTP with positive skin test and a history of anaphylaxis. All patients underwent a desensitization protocol with commercial peach juice. Rising doses of peach juice were administered, starting with an initial dose of seven drops of a 1/1000 dilution and finishing with a dose of 5 ml at visit 17. At visit 18, all patients performed an open challenge with whole juice at a cumulative dose of 200 ml. All adverse reactions occurring during the administration of the different doses were recorded. Levels of rPru p 3 in the juice were quantified.

Results

There were no severe reactions during the desensitization process in the 24 patients. Seven patients (29%) reported mild oral symptoms, and two patients (8%) had urticaria associated with co-factors (one due to exercise and another due to non-steroidal anti-inflammatory drugs). Nineteen patients were able to swallow 5 ml of juice and five withdrew from the study. In two pregnant patients the final challenge was not performed. In all, 17/24 patients were able to consume 200 ml peach juice without developing symptoms.

Conclusions

Oral immunotherapy with the regimen used in this study is an effective and safe short-term therapeutic option for patients with allergy to LTPs. Commercial peach juice appears to be suitable for this treatment.

GRADE-ing the Benefit/Risk Equation in Food Immunotherapy

Purpose of Review

We reviewed the existing evidence base to desensitisation for food allergy, applying the Grading of Recommendations, Assessment, Development and Evaluation approach to discuss whether desensitisation is likely to become part of routine treatment for patients with food allergy.

Recent Findings

Desensitisation for food allergy to peanut, egg and cow’s milk is efficacious, but whether such interventions are cost-effective is less clear, due to the issues over a sustained desensitisation effect and the increase in allergic reactions occurring in patients on treatment. Few studies have assessed the change in health-related quality of life associated with treatment, and most have not considered discordance between parent-reported changes in health-related quality of life (HRQL) outcomes compared to those of the patients themselves; none to date have controlled for the improvement in HRQL occurring after initial challenge which will confound outcomes.

Summary

The lack of longer-term safety and cost-effectiveness data, as well as an absence of current consensus in the reporting of patient-relevant outcomes, must be addressed in order to be able to recommend the introduction of desensitisation as a routine treatment in healthcare systems.

Non-digestible oligosaccharides scFOS/lcFOS facilitate safe subcutaneous immunotherapy for peanut allergy

BACKGROUND

Improving the safety of subcutaneous immunotherapy (SCIT) for food allergy is necessary to reduce side effects and achieve long-term tolerance. We determined the effect of dietary supplementation with 1% non-digestible short- and long-chain fructo-oligosaccharides (scFOS/lcFOS) on safety and efficacy of SCIT using a peanut allergy mouse model.

METHODS

After sensitization, mice received a scFOS/lcFOS or control diet for the rest of the study. To study safety of SCIT, mice were dosed with a single subcutaneous injection of peanut extract (PE) or PBS. To study efficacy, mice were dosed subcutaneously (SCIT, 3 times/week) with PE or PBS for 3 weeks. Hereafter, acute allergic skin responses, anaphylactic shock symptoms and body temperature were assessed. To study the mechanism in vitro, the human IgE receptor (FcεRI)-transfected rat mast cell (RBL) line was sensitized with an oligoclonal pool of chimeric human (chu)IgE antibodies against bovine β-lactoglobulin (BLG) and incubated with the oligosaccharides before exposure to BLG to assess direct the effect on degranulation.

RESULTS

scFOS/lcFOS reduced anaphylaxis caused by a single PE SCIT dose. scFOS/lcFOS alone also reduced the acute allergic skin response. Moreover, scFOS/lcFOS supplementation resulted in lower MMCP-1 levels in serum after PE SCIT dose compared to control diet, while antibody levels were not affected by the diet. In vitro incubation with scFOS/lcFOS at 0.5% suppressed the degranulation of IgE-sensitized RBL cells. However, dietary supplementation with scFOS/lcFOS did not improve the efficacy of SCIT.

CONCLUSIONS

We show that scFOS/lcFOS diet improves the safety of SCIT, as evidenced by lower anaphylactic responses without compromising the efficacy in a mouse model for peanut allergy. This effect is likely to result from the suppression of mast cell effector function.

Home-based cow's milk reintroduction using a milk ladder in children less than 3 years old with IgE-mediated cow's milk allergy

BACKGROUND

The development of tolerance to cow's milk in allergic children is best determined by supervised baked milk exposure. Widely recommended hospital-based challenges can potentially delay contact because of resource limitations.

OBJECTIVE

We sought to determine the efficacy and safety of our low-dose home-based reintroduction programme.

METHODS

In our allergy service, children with IgE-mediated cow's milk allergy who met set criteria (presenting with skin and/or gastrointestinal symptoms only and skin prick test < 8 mm) are considered for home-based milk reintroduction (HMR). Early contact is low-dose ingestion of a commercial baked milk biscuit with slow gradual further exposure followed by increasing milk contact using a milk ladder. We retrospectively reviewed 4-6 monthly attendance records assessing allergic symptoms, evolving milk tolerance, and compliance. Tolerance was determined using a 7 scale scoring system based on the milk ladder.

RESULTS

The clinic attendance and dietetic contact records of 86 children (49 girls) who underwent HMR were reviewed. HMR was started at a median of 13 months with 49% 8-12 months, 40% 13-18 months and 11% 19-33 months. Allergic symptoms were reported in 81 (43%) of 189 dietetic reviews, 65 (80%) of which were from the milk ladder; no patient experienced anaphylaxis requiring treatment with intramuscular adrenaline. After four reviews, only eight patients were not tolerating almost all dairy products, and there was a high rate of completion with only a further seven patients lost to the programme.

CONCLUSION AND CLINICAL RELEVANCE

Cow's milk can be successfully and safely reintroduced in a cautious low-dose exclusively home-based programme in the appropriate clinical and family setting.

The Impact of Immune Interventions: A Systems Biology Strategy for Predicting Adverse and Beneficial Immune Effects

Despite scientific advances it remains difficult to predict the risk and benefit balance of immune interventions. Since a few years, network models have been built based on comprehensive datasets at multiple molecular/cellular levels (genes, gene products, metabolic intermediates, macromolecules, cells) to illuminate functional and structural relationships. Here we used a systems biology approach to identify key immune pathways involved in immune health endpoints and rank crucial candidate biomarkers to predict adverse and beneficial effects of nutritional immune interventions. First, a literature search was performed to select the molecular and cellular dynamics involved in hypersensitivity, autoimmunity and resistance to infection and cancer. Thereafter, molecular interaction between molecules and immune health endpoints was defined by connecting their relations by using database information. MeSH terms related to the immune health endpoints were selected resulting in the following selection: hypersensitivity (D006967: 184 genes), autoimmunity (D001327: 564 genes), infection (parasitic, bacterial, fungal and viral: 357 genes), and cancer (D009369: 3173 genes). In addition, a sequence of key processes was determined using Gene Ontology which drives the development of immune health disturbances resulting in the following selection: hypersensitivity (164 processes), autoimmunity (203 processes), infection (187 processes), and cancer (309 processes). Finally, an evaluation of the genes for each of the immune health endpoints was performed, which indicated that many genes played a role in multiple immune health endpoints, but also unique genes were observed for each immune health endpoint. This approach helps to build a screening/prediction tool which indicates the interaction of chemicals or food substances with immune health endpoint-related genes and suggests candidate biomarkers to evaluate risks and benefits. Several anti-cancer drugs and omega 3 fatty acids were evaluated as in silico test cases. To conclude, here we provide a systems biology approach to identify genes/molecules and their interaction with immune related disorders. Our examples illustrate that the prediction with our systems biology approach is promising and can be used to find both negatively and positively correlated interactions. This enables identification of candidate biomarkers to monitor safety and efficacy of therapeutic immune interventions.

Butyrate Enhances Desensitization Induced by Oral Immunotherapy in Cow's Milk Allergic Mice

Background

In previous studies, we showed that a fructo-oligosaccharide- (FOS-) supplemented diet enhanced oral immunotherapy (OIT) efficacy in a mouse model for cow's milk allergy. Fermentation of FOS by intestinal bacteria leads to production of short-chain fatty acids (SCFA) including butyrate.

Aim

To investigate the contribution of butyrate in the enhanced efficacy of OIT + FOS.

Methods

C3H/HeOuJ mice were sensitized and received OIT with or without FOS or butyrate supplementation. After treatment, whole blood was collected to conduct a basophil activation test (BAT) and allergen challenges were performed to measure acute allergic symptoms. CD4 + CD25 + regulatory T cells (Tregs) were isolated from treated mice or differentiated in vitro and used in a bone marrow-derived mast cell (BMMC) suppression assay. Cecum content was collected to analyze SCFA concentrations.

Results

Allergen-induced basophil activation was reduced in OIT + butyrate samples compared to OIT. Accordingly, the acute allergic skin response and mast cell degranulation upon challenge were reduced in OIT + butyrate and OIT + FOS mice compared to sensitized controls. Butyrate was increased in the cecum content of OIT + FOS mice compared to OIT mice and sensitized controls. Treg-mediated BMMC suppression was enhanced after in vivo butyrate and FOS exposure in combination with OIT but with a more pronounced effect for butyrate.

Conclusion

Butyrate supplementation enhanced OIT-induced desensitization of basophils and mast cells and Treg functionality. Only OIT + FOS treatment induced potential microbial alterations, shown by increased butyrate levels in cecum content. Both butyrate and FOS are promising candidates to improve OIT efficacy in human studies to treat food allergies.

The Impact of Baked Egg and Baked Milk Diets on IgE- and Non-IgE-Mediated Allergy

Baked milk (BM) and baked egg (BE) diets are increasingly used in the management of milk and egg allergy, rather than avoidance. Children with tolerance versus reactivity to BM and BE may have smaller skin prick test and lower specific IgE, and BM-tolerant children have less basophil reactivity and more peripheral T regulatory cells. However, most milk- and egg-allergic children tolerate BM and BE and an individual's reactivity is unpredictable. Non-reactivity is due to conformational changes in the allergens. Significant differences in the published advice about methods of introduction exist from graded introduction at home to a medically supervised full dose. These approaches carry different risks and may have different immunological effects. Reactivity to BM is a predictor of a severe milk allergy. Therefore, medical supervision for BM and BE introduction is prudent. The baked diet allows dietary liberation. Most, but not all, BM- and BE-tolerant children continue eating the baked foods. The prognosis of children who can eat BM and BE is favorable with likely resolution of their allergy over the next few years. Murine models of BE diets demonstrate that heated egg can impart clinical protection against anaphylaxis and cause immune changes. Most observational human studies of BM and BE diets demonstrate clinical resolution of allergy and favorable immune changes versus regular care controls. However, the one randomized controlled trial for the BE diet in BE-tolerant children did not support an immune-modifying effect of the BE diet. Another study of BE immunotherapy is expected to be completed in 2018. There is currently no evidence for prevention of allergy with the baked diets. There may be a future role for BM and BE in liberating the diets of individuals with non-IgE-mediated allergy given recent studies that a subset of these patients can consume BM without a clinical reaction.

Food-induced fatal anaphylaxis: From epidemiological data to general prevention strategies

BACKGROUND

Anaphylaxis hospitalizations are increasing in many countries, in particular for medication and food triggers in young children. Food-related anaphylaxis remains an uncommon cause of death, but a significant proportion of these are preventable.

AIM

To review published epidemiological data relating to food-induced anaphylaxis and potential risk factors of fatal and/or near-fatal anaphylaxis cases, in order to provide strategies to reduce the risk of severe adverse outcomes in food anaphylaxis.

METHODS

We identified 32 published studies available in MEDLINE (1966-2017), EMBASE (1980-2017), CINAHL (1982-2017), using known terms and synonyms suggested by librarians and allergy specialists.

RESULTS

Young adults with a history of asthma, previously known food allergy particularly to peanut/tree nuts are at higher risk of fatal anaphylaxis reactions. In some countries, cow's milk and seafood/fish are also becoming common triggers of fatal reactions. Delayed adrenaline injection is associated with fatal outcomes, but timely adrenaline alone may be insufficient. There is still a lack of evidence regarding the real impact of these risk factors and co-factors (medications and/or alcohol consumption, physical activities, and mast cell disorders).

CONCLUSIONS

General strategies should include optimization of the classification and coding for anaphylaxis (new ICD 11 anaphylaxis codes), dissemination of international recommendations on the treatment of anaphylaxis, improvement of the prevention in food and catering areas, and dissemination of specific policies for allergic children in schools. Implementation of these strategies will involve national and international support for ongoing local efforts in relationship with networks of centres of excellence to provide personalized management (which might include immunotherapy) for the most at-risk patients.

Recent developments and highlights in biomarkers in allergic diseases and asthma

The potential of precision medicine in allergy and asthma has only started to be explored. A significant clarification in the pathophysiology of rhinitis, chronic rhinosinusitis, asthma, food allergy and drug hypersensitivity was made in the last decade. This improved understanding led to a better classification of the distinct phenotypes and to the discovery of new drugs such as biologicals, targeting phenotype-specific mechanisms. Nevertheless, many conditions remain poorly understood such as non-eosinophilic airway diseases or non-IgE-mediated food allergy. Moreover, there is a need to predict the response to specific therapies and the outcome of drug and food provocations. The identification of patients at risk of progression towards severity is also an unmet need in order to establish adequate preventive or therapeutic measures. The implementation of precision medicine in the clinical practice requires the identification of phenotype-specific markers measurable in biological matrices. To become useful, these biomarkers need to be quantifiable by reliable systems, and in samples obtained in an easy, rapid and cost-efficient way. In the last years, significant research resources have been put in the identification of valid biomarkers for asthma and allergic diseases. This review summarizes these recent advances with focus on the biomarkers with higher clinical applicability.

AR101 Oral Immunotherapy for Peanut Allergy

BACKGROUND

Peanut allergy, for which there are no approved treatment options, affects patients who are at risk for unpredictable and occasionally life-threatening allergic reactions.

METHODS

In a phase 3 trial, we screened participants 4 to 55 years of age with peanut allergy for allergic dose-limiting symptoms at a challenge dose of 100 mg or less of peanut protein (approximately one third of a peanut kernel) in a double-blind, placebo-controlled food challenge. Participants with an allergic response were randomly assigned, in a 3:1 ratio, to receive AR101 (a peanut-derived investigational biologic oral immunotherapy drug) or placebo in an escalating-dose program. Participants who completed the regimen (i.e., received 300 mg per day of the maintenance regimen for approximately 24 weeks) underwent a double-blind, placebo-controlled food challenge at trial exit. The primary efficacy end point was the proportion of participants 4 to 17 years of age who could ingest a challenge dose of 600 mg or more, without dose-limiting symptoms.

RESULTS

Of the 551 participants who received AR101 or placebo, 496 were 4 to 17 years of age; of these, 250 of 372 participants (67.2%) who received active treatment, as compared with 5 of 124 participants (4.0%) who received placebo, were able to ingest a dose of 600 mg or more of peanut protein, without dose-limiting symptoms, at the exit food challenge (difference, 63.2 percentage points; 95% confidence interval, 53.0 to 73.3; P<0.001). During the exit food challenge, the maximum severity of symptoms was moderate in 25% of the participants in the active-drug group and 59% of those in the placebo group and severe in 5% and 11%, respectively. Adverse events during the intervention period affected more than 95% of the participants 4 to 17 years of age. A total of 34.7% of the participants in the active-drug group had mild events, as compared with 50.0% of those in the placebo group; 59.7% and 44.4% of the participants, respectively, had events that were graded as moderate, and 4.3% and 0.8%, respectively, had events that were graded as severe. Efficacy was not shown in the participants 18 years of age or older.

CONCLUSIONS

In this phase 3 trial of oral immunotherapy in children and adolescents who were highly allergic to peanut, treatment with AR101 resulted in higher doses of peanut protein that could be ingested without dose-limiting symptoms and in lower symptom severity during peanut exposure at the exit food challenge than placebo. (Funded by Aimmune Therapeutics; PALISADE ClinicalTrials.gov number, NCT02635776 .).

The role of regulatory T cells in the acquisition of tolerance to food allergens in children

Food allergy is a pathological immune reaction that identifies certain harmless food proteins, usually tolerated by the majority of the people, as a threat. The prevalence of these food allergies is increasing worldwide and currently affects 8% of children. Exacerbated reactions to milk, egg and peanut are the most frequent in the pediatric population. It is well known that allergic diseases are a type 2 T-helper (Th2) immune response, characterized by the elevated production of IgE antibodies. However, little is known about the immune mechanisms responsible for the development of clinical tolerance toward food allergens. Recent studies have suggested the key role of regulatory T cells (Tregs) in controlling allergic inflammation. In this review, we discuss the importance of Tregs in the pathogenesis of food allergy and the acquisition of oral tolerance in children. Further investigation in this area will be crucial for the identification of predictive markers and the development of new therapies, which will represent a clinical and social benefit for these allergic diseases.

Dietary Supplementation with Nondigestible Oligosaccharides Reduces Allergic Symptoms and Supports Low Dose Oral Immunotherapy in a Peanut Allergy Mouse Model

SCOPE

A major downside of oral immunotherapy (OIT) for food allergy is the risk of severe side effects. Non-digestible short- and long-chain fructo-oligosaccharides (scFOS/lcFOS) reduce allergy development in murine models. Therefore, it is hypothesized that scFOS/lcFOS can also support the efficacy of OIT in a peanut allergy model.

METHODS AND RESULTS

After sensitization to peanut extract (PE) using cholera toxin, C3H/HeOuJ mice are fed a 1% scFOS/lcFOS or control diet and receive OIT (1.5 or 15 mg PE). Hereafter, mice are exposed to PE via different routes to determine the safety and efficacy of treatment in clinical outcomes, PE-specific antibody production, and numbers of various immune cells. scFOS/lcFOS increases short-chain fatty acid levels in the caecum and reduce the acute allergic skin response and drop in body temperature after PE exposure. Interestingly, 15 mg and 1.5 mg OIT with scFOS/lcFOS induce protection against anaphylaxis, whereas 1.5 mg OIT alone does not. OIT, with or without scFOS/lcFOS, induces PE-specific immunoglobulin (Ig) IgG and IgA levels and increases CD103+ dendritic cells in the mesenteric lymph nodes.

CONCLUSIONS

scFOS/lcFOS and scFOS/lcFOS combined with low dose OIT are able to protect against a peanut-allergic anaphylactic response.

Quality of Life of Food-Allergic Patients Before, During, and After Oral Immunotherapy

BACKGROUND

Oral immunotherapy (OIT) for food allergy is demanding but data on patients' quality of life (QOL) throughout the process are limited.

OBJECTIVE

To characterize changes in QOL of food-allergic patients during and after OIT.

METHODS

In a prospective cohort study, the Food Allergy Quality of Life Questionnaire-Parental Form (FAQLQ-PF) was administered to parents of 191 consecutive children aged 4 to 12 years undergoing OIT for food allergy. Questionnaires were administered at OIT initiation, mid up-dosing, upon reaching maintenance, and after 6 months of follow-up. Age- and sex-matched food-allergic children (n = 48) not undergoing OIT served as controls.

RESULTS

FAQLQ-PF scores had significantly improved (decreased) from OIT initiation to reaching full maintenance (emotional impact [EI], 3.66-3.32, P = .001; food anxiety [FA], 3.90-3.32, P < .001; social and dietary limitation [SDL], 3.50-2.94, P < .001; and total score, 3.69-3.19, P < .001) and partial maintenance, whereas no change was noted in control patients. Worse baseline QOL, single food allergy, and a younger age predicted greater QOL improvement. Of the 85 (88.5%) patients who completed the FAQLQ-PF at mid up-dosing and for whom QOL deteriorated, a significant improvement was noted upon reaching maintenance. Additional significant improvement in QOL was observed in the 95 (88.8%) patients who completed the FAQLQ-PF 6 months after reaching maintenance (EI, 3.414-2.993, P = 0.049; FA, 3.37-2.593, P = .001; SDL, 2.989-2.264, P = .001; and total score, 3.266-2.614, P = .001).

CONCLUSION

The QOL of food-allergic children improves significantly upon reaching OIT maintenance, with additional improvement 6 months later. The detrimental effect of OIT on some patients' QOL during up-dosing is reversed upon reaching maintenance.

Immune mechanisms of oral immunotherapy

Oral immunotherapy (OIT) has demonstrated reproducibly successful desensitization in patients with food allergy completing clinical trials and, in some studies, sustained unresponsiveness. These clinical outcomes have been associated with characteristic modifications in the allergen-specific immune response, but a detailed synthesis of OIT's mechanisms of action is lacking. In this rostrum we review the current evidence regarding the human immune response to OIT, explore possible mechanisms, and identify knowledge gaps for future research.

Food allergy and atopic dermatitis: Prediction, progression, and prevention

The rising burden of allergic diseases in childhood requires a compelling need to identify individuals at risk for atopy very early in life or even predict the onset of food allergy and atopic dermatitis since pregnancy. The development and clinical phenotypes of atopic diseases in childhood depend on a complex interaction between genetic and environmental factors, such as allergen exposure, air pollution, and infections. Preventive strategies may include avoidance measures, diet supplements, and early complementary food introduction. Overall, the management of allergic diseases has been improving to date toward a patient's tailored approach. This review will cover the current understanding of risk factors, prediction, and management of food allergy and atopic dermatitis in childhood and discuss how these may contribute to the modification of the natural history of food allergy and atopic dermatitis.

Changes in patient quality of life during oral immunotherapy for food allergy

BACKGROUND

Quality of life (QOL) is impaired in patients with food allergy and improves following oral immunotherapy (OIT). However, the treatment itself is prolonged and demanding. We examined changes in patient QOL during OIT for food allergy.

METHODS

The FAQLQ-PF was administered to children aged 4-12 years undergoing OIT for milk, peanut, or egg allergy, at the beginning and after 4 months of treatment. Patients were categorized as improved, unchanged, or diminished FAQLQ-PF (>0.5 point decrease, a change of ≤0.5 points, or >0.5 increase, respectively) and compared. Food-allergic patients not undergoing OIT served as controls.

RESULTS

The Food Anxiety, Social and Dietary Limitation, and total FAQLQ-PF scores improved significantly during the study period (P=.001, P=.018, and P=.01, respectively) in treated but not in control patients, while the Emotional Impact did not. The change in the FAQLQ-PF was independent of the maximal tolerated dose at baseline or following four months of treatment, the pace of dose increase, or the number or severity of reactions experienced. The total FAQLQ-PF score was inversely associated with the score at baseline on multivariate analysis (regression coefficient=-0.56, P<.001). That was driven primarily by improvement in QOL scores in patients with high score (worse QOL) at baseline. Some patients with low FAQLQ-PF score (better QOL) at baseline deteriorated.

CONCLUSIONS

QOL of patients with food allergy improves in some but deteriorates in others during OIT. Patients with impaired QOL at baseline improve significantly despite the treatment burden. Some patients with better QOL at baseline might deteriorate during OIT.

Immunomodulating peptides for food allergy prevention and treatment

Among the most promising strategies currently assayed against IgE-mediated allergic diseases stands the possibility of using immunomodulating peptides to induce oral tolerance toward offending food allergens or even to prevent allergic sensitization. This review focuses on the beneficial effects of food derived immunomodulating peptides on food allergy, which can be directly exerted in the intestinal tract or once being absorbed through the intestinal epithelial barrier to interact with immune cells. Food peptides influence intestinal homeostasis by maintaining and reinforcing barrier function or affecting intestinal cell-signalling to nearby immune cells and mucus secretion. In addition, they can stimulate cells of the innate and adaptive immune system while supressing inflammatory responses. Peptides represent an attractive alternative to whole allergens to enhance the safety and efficacy of immunotherapy treatments. The conclusions drawn from curative and preventive experiments in murine models are promising, although there is a need for more pre-clinical studies to further explore the immunomodulating strategy and its mechanisms and for a deeper knowledge of the peptide sequence and structural requirements that determine the immunoregulatory function.