Oral immunotherapy for treatment of egg allergy in children

Long-term outcome of peanut oral immunotherapy-Real-life experience

BACKGROUND

Oral immunotherapy (OIT) is currently recommended as a treatment option for peanut-allergic patients. Data regarding its long-term compliance and efficacy in real life are required.

METHODS

Peanut-allergic patients aged ≥4 years were enrolled in a single-center clinical OIT program. Buildup to 3000 mg peanut protein was performed. Patients reaching this dose before or after 12/2014 were instructed to consume 3000 or 1200 mg daily, respectively. Patients were followed ≥6 months after reaching maintenance and rechallenged to 3000 mg.

RESULTS

Of the 145 patients studied, 113 (77.9%) were fully desensitized to 3000 mg and 133 (91.7%) were desensitized to ≥300 mg. 21/145 patients (14.5%) required adrenaline for home-dose reactions during buildup. Non-anaphylactic gastrointestinal symptoms, experienced by 9 patients (6.2%), reversed with dose reduction. Of the 111 patients available for analysis 6 months after reaching 3000 mg, 97 (87.4%) continued regular peanut consumption. Only 2/111 patients (1.8%) required adrenaline over the long-term (median, range; 18, 6-75 months) follow-up. Adherence to treatment was significantly higher in patients consuming 1200 mg (73/76, 96.1%) vs those consuming 3000 mg (24/35, 72.2%), (P = .001). A higher maintenance dosage and home adrenaline requirement during buildup predicted adherence cessation (OR 12.5, P = .001; and OR 7.8, P = .02, respectively). 63/64 patients (98.4%) consuming 1200 mg maintenance dose were successfully rechallenged to 3000 mg.

CONCLUSIONS

This real-life experience demonstrates the efficacy of peanut OIT long-term. A lower maintenance dose minimized treatment cessation while maintaining desensitization. OIT should be performed in qualified centers given the prevalence of adverse reactions, particularly during buildup.

A general strategy for de novo immunotherapy design: the active treatment of food allergy

INTRODUCTION

IgE-mediated food allergy (FA) has been emerging as a public health priority. It is a potentially life-threatening condition with negative impact on the quality of life of patients and their family and its prevalence is increasing in westernized countries in the recent two decades. The current standard approach to FA consists of the strict avoidance of the triggering food. However, an elimination diet may be difficult and frustrating, above all for those foods (e.g. milk and egg) that are pivotal in the common diet. Oral immunotherapy (OIT) may increase the amount of food that the patient can intake without reaction and reduce the risk of potential life-threatening allergic reactions. It is currently considered the most promising treatment for FA. However, many gaps are still unsolved. Areas covered: The aim of this review is to shed light on the current evidence and the main needs in OIT in order to stimulate the development of longitudinal, prospective, and well-designed studies with the final goal of a 'precision medicine.' Expert commentary: Clinical trials for OIT conducted so far are extremely heterogeneous. The aim in the near future is to identify the most suitable candidates to OIT and algorithms for treatments tailored on well-characterized subpopulations of patients.

Is Allergen Immunotherapy in Children Disease Modifying? A Review of the Evidence

PURPOSE OF REVIEW

Although evidence supports a beneficial effect of allergen immunotherapy on the symptoms of allergic respiratory disease and food allergy, it is not clear whether immunotherapy modifies the natural history of these conditions.

RECENT FINDINGS

In aeroallergen immunotherapy, studies suggest that prevention of asthma can be attained. Less evident is the ability of immunotherapy to prevent new allergen sensitizations and more studies are needed to test whether immunotherapy can continue suppressing airway symptoms after treatment discontinuation. In food allergen immunotherapy, there is evidence that unresponsiveness to a food challenge can be sustained in some treatment recipients, but little knowledge exists as to the dose and duration of treatment that can optimize this effect. Suggestive evidence exists that allergen immunotherapy can modify allergic disease in children, but definitive studies are lacking. More research in the field is required.

Study design with staggered sampling times for evaluating sustained unresponsiveness to peanut sublingual immunotherapy

In this work, we delineate an altered study design of a pre-existing clinical trial that is currently being implemented in the Department of Pediatrics at the University of North Carolina at Chapel Hill. The purpose of the ongoing investigation of the desensitized pediatric cohort is to address the effectiveness of sublingual immunotherapy in achieving sustained unresponsiveness (SU) as assessed by repeated double-blind placebo-controlled food challenges (DBPCFC). With scarce published literature characterizing SU, the length of time off-therapy that would represent clinically meaningful benefit remains undefined. We use the new design features to assess time to loss of SU, an important efficacy endpoint, that to our knowledge, no prior study has investigated. Our work has two-fold objectives: first is to propose and discuss aspects of the altered design that would allow us to study SU and second is to explore methodology to evaluate the time to loss of SU and its association with risk factors in the context of the data originating from the trial. The salient feature of the new design is the allocation scheme of study subjects to staggered sampling timepoints when a subsequent DBPCFC is administered. Due to this feature, the time to loss of SU is either left or right censored. Additionally, some participants at study entry fail the DBPCFC, leading to what can be construed as an instantaneous failure. Through in-depth numerical studies, we examine the performance and power of a recently proposed mixture proportional hazards model specifically designed for the analysis of interval-censored data subject to instantaneous failures.

Nationwide questionnaire-based survey of oral immunotherapy in Japan

BACKGROUND

Clinical trials on oral immunotherapy (OIT) have been increasing for nearly a decade; however, several national guidelines do not recommend OIT as a standardized procedure. The aim of this study was to obtain insights into the current use and practice of OIT in Japan.

METHODS

A first questionnaire was mailed to 524 training and teaching facilities of the Japan Pediatric Society. The first survey requested information on the implementation of OIT, whereas the second survey aimed to gather more detailed information on OIT, such as its safety.

RESULTS

In total, 360 facilities (69%) responded to the survey; among them, 102 (28%) provided OIT to 7973 patients [1544 received OIT while hospitalized (inpatient OIT), whereas 6429 received OIT without hospitalization (outpatient OIT)]. Approval for OIT was obtained from an ethics committee or institutional review board in 89% and 31% of facilities for inpatient and outpatient OIT, respectively. In inpatient OIT, immediate allergic reactions requiring treatment occurred in 68% of patients while hospitalized, and in another 56%, following discharge. In contrast, 11% of patients developed immediate allergic reactions in outpatient OIT. Adrenaline injections at home were required in 2%. Sixteen patients developed adverse reactions other than immediate allergic reactions, among which eosinophilic gastroenteritis was most common.

CONCLUSIONS

OIT is widely provided not only as clinical research but also as general practice in Japan. However, because there is a high risk of developing anaphylaxis at home, OIT should be conducted carefully as in a clinical research setting taking safety into consideration.

One Child's Food Fight: A Case Study of Oral Immunotherapy Treatment for Food Allergies

The prevalence of food allergy has risen dramatically in the last two decades. Primary care providers encounter food-allergic children on a daily basis. Although the standard of care has traditionally been strict avoidance of the allergen and advisement to carry an epinephrine autoinjector in case of an accidental exposure resulting in a severe reaction, food allergy research has progressed in the past decade concerning various immunotherapies that may provide an alternate treatment strategy. Oral immunotherapy (OIT), performed under the supervision of an allergist, is the most widely studied of these therapies. In the past, OIT has been available in the realm of clinical trials, but it is now being offered by a small but increasing number of allergists in private practice throughout the United States. Pediatric primary care clinicians should be aware of both the risks and possible benefits of this treatment, because they are likely to encounter patients who may inquire about OIT in their practices. In this case report, use of OIT will be reviewed in the treatment of a food-allergic child.

Unproven Diagnostic Tests for Food Allergy

The gold standard for diagnosis of immunoglobulin E (IgE)-mediated food allergy remains the oral food challenge, with serum IgE testing and skin prick testing serving as acceptable alternatives. However, the increase in prevalence of food allergy (both physician diagnosed and patient suspected) has led patients to pursue a variety of other alternative diagnostic procedures for suspected food allergy, which are reviewed in this article. These procedures (IgG testing, electrodermal testing, cytotoxic testing, provocation/neutralization, and applied kinesiology) have largely been unproven and may lead to unnecessary elimination diets.

Debates in Allergy Medicine: Oral immunotherapy shortens the duration of milk and egg allergy - the con argument

Oral immunotherapy (OIT) has been shown to be effective for inducing desensitization in children with cow’s milk and egg allergy. In contrast, there is limited evidence that OIT can induce tolerance or sustained unresponsiveness in food allergic patients. Sustained unresponsiveness, determined by a food challenge following a period of secondary avoidance, has been suggested to reflect a more enduring state of tolerance and is pertinent when considering the ability of OIT to shorten the duration of food allergy. While it has been shown that children who tolerate baked forms of egg and milk are more likely to develop tolerance compared to those who are allergic to baked forms of these foods, there is no convincing evidence that OIT using modified allergen in baked foods can hasten resolution of cow’s milk and egg allergy. Instead, it is likely that baked milk and baked egg tolerant children represent a sub-phenotype of milk and egg allergy that is more likely to resolve spontaneously over time.

Debates in Allergy Medicine: Does oral immunotherapy shorten the duration of milk and egg allergy? The pro argument

The development of oral tolerance or food allergy is an active process, related to dynamic interactions between host immune cells, microbiome, dietary factors, and food allergens. Oral tolerance is the default immune response in the gut. A food allergy occurs when this process fails and a pathologic Th2 response is activated. Oral food immunotherapy (OIT) aims to restore immune tolerance in food-allergic individuals. The stimulation of Tregs production seems to represent a crucial step in inducing long-term tolerance, but other mechanisms (e.g., the suppression of mast cell and basophil reactivity, changes in allergen-specific cells with regulatory markers) are involved. Several studies reported the efficacy of OIT in terms of "sustained unresponsiveness" (SU), an operational definition of immune tolerance. In successfully treated subjects, the ability to pass an oral food challenge 2 to 8 weeks after stopping the food allergen exposure seems to be conditioned by the treatment starting age, frequency, amount or type of food consumed, and by the duration of the maintenance phase. Based on the available data, the percentage of milk- and egg-allergic subjects achieving sustained unresponsiveness after an OIT ranges from 21% to 58,3%. A comprehensive understanding of mechanisms underlying the induction of oral tolerance with OIT, or natural tolerance to food allergens in healthy individuals, could potentially lead to advances in development of better treatment options for food allergic patients.

Immunotherapy for IgE-mediated wheat allergy

Among various routes of immunotherapy for food allergy, oral immunotherapy (OIT) appears to have a promising result due to its ability to modify abnormal immunologic mechanism of IgE-mediated food allergy. Other methods for immunomodulation such as sublingual (SLIT) or epicutaneous (EPIT) immunotherapy which carry lower rates of systemic reactions, may have less efficacy. Wheat has recently been recognized as a more common cause of food-induced anaphylaxis than previously recognized, especially among young children, around the world. In wheat allergic patients, avoidance recommended as standard recommendation is not easy to follow, because wheat has been used as a common constituents in various kinds of consumed foods in every day's life. Therefore, wheat OIT may be considered as an alternative treatments of those in which wheat avoidance is not sufficient to avert frequent events of anaphylaxis resulting from inadvertent exposure to small amount of wheat among this population. Currently, only few clinical trials about wheat OIT are available. In this review, we discuss available protocols of wheat OIT, initial starting dose, maintenance dose, and the strategies to minimize the side effects during the treatment.

Update on oral immunotherapy for egg allergy

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

Tissue-Specific Expression of the Low-Affinity IgG Receptor, FcγRIIb, on Human Mast Cells

Immediate hypersensitivity reactions are induced by the interaction of allergens with specific IgE antibodies bound via FcεRI to mast cells and basophils. While these specific IgE antibodies are needed to trigger such reactions, not all individuals harboring IgE exhibit symptoms of allergy. The lack of responsiveness seen in some subjects correlates with the presence of IgG antibodies of the same specificity. In cell culture studies and in vivo animal models of food allergy and anaphylaxis such IgG antibodies have been shown to exert suppression via FcγRIIb. However, the reported absence of this inhibitory receptor on primary mast cells derived from human skin has raised questions about the role of IgG-mediated inhibition of immediate hypersensitivity in human subjects. Here, we tested the hypothesis that mast cell FcγRIIb expression might be tissue specific. Utilizing a combination of flow cytometry, quantitative PCR, and immunofluorescence staining of mast cells derived from the tissues of humanized mice, human skin, or in fixed paraffin-embedded sections of human tissues, we confirm that FcγRIIb is absent from dermal mast cells but is expressed by mast cells throughout the gastrointestinal tract. IgE-induced systemic anaphylaxis in humanized mice is strongly inhibited by antigen-specific IgG. These findings support the concept that IgG, signaling via FcγRIIb, plays a physiological role in suppressing hypersensitivity reactions.

The effect of oral immunotherapy treatment in severe IgE mediated milk, peanut, and egg allergy in adults

INTRODUCTION

The standard care of severe food allergy in both adults and children means avoidance of allergens. In recent years promising results of oral immunotherapy (OIT) have been reported in children. In adults, information on OIT in severe food allergy is very limited.

OBJECTIVE

We aimed to study if OIT is possible in adults.

METHODS

We report OIT results in 10 adult patients with milk OIT, nine adult patients with peanut OIT, and four adult patients with egg OIT. The allergy was confirmed with allergen specific IgE tests and oral food challenges (open in milk allergy and double-blind in peanut and egg allergy). The OIT was performed as open.

RESULTS

The median dose of protein that led to discontinuation of allergen challenge because of symptoms was 7.5 mg in milk allergy, 25 mg in peanut allergy, and 15 mg in egg allergy. The median period of OIT was 515 days. Currently on OIT are 6/10 milk allergic patients, 4/9 peanut allergic patients and 3/4 egg allergic patients. The median dose of milk protein increased by 60-fold during OIT compared to the allergen challenge dose. In peanut OIT the median dose increased by eightfold and in egg allergy the dose increased with OIT by 35-fold. Local itching was the most common side effect of OIT (73.9% of the patients), four patients reported having used epinephrine autoinjector and three patients having needed emergency room treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

OIT can be given in adult patients with severe milk, peanut, or egg allergy only in selected cases. OIT leads into desensitization but it is not clear whether persistent tolerance can be achieved. Mild adverse events during OIT are common.

Wheat oral immunotherapy was moderately successful but was associated with very frequent adverse events in children aged 6-18 years

AIM

This study investigated oral immunotherapy (OIT) for children aged 6-18 years with wheat allergies.

METHODS

Well-cooked wheat spaghetti was given to 100 children with wheat allergies every day for 17 weeks, increasing from 0.3 to 2000 mg of wheat protein, followed by three- and nine-month maintenance phases. Blood samples were taken before therapy and at follow-up visits. The study was carried out in 2009-2015 in four Finnish paediatric allergology units.

RESULTS

The children (67% male) had a mean age of 11.6 years (range 6.1-18.6), and 57 were using wheat daily 16 months after the initiation of therapy. Allergic symptoms occurred in 94/100 children: mild in 34, moderate in 36 and severe in 24. Specific immunoglobulin E (IgE) for ω-5-gliadin was significantly higher in patients who did not reach the target dose and were related to the intensity of reactions.

CONCLUSION

The majority (57%) of children with wheat allergies could use wheat in their daily diet 16 months after the initiation of OIT, but 94/100 had adverse reactions and 60 were moderate or severe. Specific IgE to ω-5-gliadin may provide a biomarker for how much wheat can be tolerated and the intensity of the reactions to immunotherapy.

Oral and sublingual immunotherapy for egg allergy

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Nanoemulsion adjuvant-driven redirection of TH2 immunity inhibits allergic reactions in murine models of peanut allergy

BACKGROUND

Immunotherapy for food allergies involves progressive increased exposures to food that result in desensitization to food allergens in some subjects but not tolerance to the food. Therefore new approaches to suppress allergic immunity to food are necessary. Previously, we demonstrated that intranasal immunization with a nanoemulsion (NE) adjuvant induces robust mucosal antibody and T_H17-polarized immunity, as well as systemic T_H1-biased cellular immunity with suppression of pre-existing T_H2-biased immunity.

OBJECTIVE

We hypothesized that immunization with food in conjunction with the nanoemulsion adjuvant could lead to modulation of allergic reactions in food allergy by altering pre-existing allergic immunity and enhancing mucosal immunity.

METHODS

Mice were sensitized to peanut with aluminum hydroxide or cholera toxin. The animals were then administered 3 monthly intranasal immunizations with peanut in the nanoemulsion adjuvant or saline. Mice were then challenged with peanut to examine allergen reactivity.

RESULTS

The NE intranasal immunizations resulted in marked decreases in T_H2 cytokine, IgG₁, and IgE levels, whereas T_H1 and mucosal T_H17 immune responses were increased. After allergen challenge, these mice showed significant reductions in allergic hypersensitivity. Additionally, the NE immunizations significantly increased antigen-specific IL-10 production and regulatory T-cell counts, and the protection induced by NE was dependent in part on IL-10. Control animals immunized with intranasal peanut in saline had no modulation of their allergic response.

CONCLUSIONS

NE adjuvant-mediated induction of mucosal T_H17 and systemic T_H1-biased immunity can suppress T_H2-mediated allergy through multiple mechanisms and protect against anaphylaxis. These results suggest the potential therapeutic utility of this approach in the setting of food allergy.

The Nuts and Bolts of Food Immunotherapy: The Future of Food Allergy

Food allergies are on the rise and have a major impact on the quality of life of the food allergic child and their family. Currently, the mainstream treatment for food allergies is strict avoidance and elimination of the allergenic food(s) from the patient's diet in order to prevent an allergic reaction. However, recent advances in research have presented new therapeutic options for food allergic patients that are potentially becoming promising alternatives to traditional treatment. Food immunotherapy is the most popular of these new emerging interventions and has been studied intensively over the last decade for various foods. In this review, we discuss this exciting new development that is aspiring to become part of the mainstream therapy for food allergy.

EAACI Guidelines on allergen immunotherapy: IgE-mediated food allergy

Food allergy can result in considerable morbidity, impairment of quality of life, and healthcare expenditure. There is therefore interest in novel strategies for its treatment, particularly food allergen immunotherapy (FA-AIT) through the oral (OIT), sublingual (SLIT), or epicutaneous (EPIT) routes. This Guideline, prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Task Force on Allergen Immunotherapy for IgE-mediated Food Allergy, aims to provide evidence-based recommendations for active treatment of IgE-mediated food allergy with FA-AIT. Immunotherapy relies on the delivery of gradually increasing doses of specific allergen to increase the threshold of reaction while on therapy (also known as desensitization) and ultimately to achieve post-discontinuation effectiveness (also known as tolerance or sustained unresponsiveness). Oral FA-AIT has most frequently been assessed: here, the allergen is either immediately swallowed (OIT) or held under the tongue for a period of time (SLIT). Overall, trials have found substantial benefit for patients undergoing either OIT or SLIT with respect to efficacy during treatment, particularly for cow's milk, hen's egg, and peanut allergies. A benefit post-discontinuation is also suggested, but not confirmed. Adverse events during FA-AIT have been frequently reported, but few subjects discontinue FA-AIT as a result of these. Taking into account the current evidence, FA-AIT should only be performed in research centers or in clinical centers with an extensive experience in FA-AIT. Patients and their families should be provided with information about the use of FA-AIT for IgE-mediated food allergy to allow them to make an informed decision about the therapy.

Food-dependent exercise-induced anaphylaxis in Japanese elementary school children

BACKGROUND

In 2012, we clarified that the prevalence of food-dependent exercise-induced anaphylaxis (FDEIA) was 0.018% in junior-high students in Yokohama, Japan. Furthermore, although different from FDEIA, one student who had completed oral immunotherapy developed anaphylaxis during exercise after eating causative food. There have been few large-scale epidemiological studies of FDEIA, however, in elementary school children, therefore we conducted an epidemiological study in elementary school children in Yokohama to clarify the frequency and characteristic of FDEIA.

METHODS

We sent a questionnaire regarding the occurrence of FDEIA to all 348 public elementary school nurses in Yokohama. We also compared the results with those for junior-high school that we previously reported. We excluded those children with a past history of immediate food allergy who had achieved desensitization status after oral immunotherapy, from FDEIA, and instead defined them as having desensitization status and exercise-induced anaphylaxis (DEIA).

RESULTS

Of 348 school nurses, 317 responded (91.1%). Overall, eight of 170 146 children were diagnosed with FDEIA, which was significantly lower than the prevalence in junior-high school students (0.0047% vs 0.018%, P = 0.0009). The causative foods were wheat (n = 4), and soy, fruit, crustaceans, and squid (n = 1 each). Four children had DEIA and the causative foods were wheat and milk (n = 2 each). Multiple episodes occurred in five children with FDEIA and in three children with DEIA.

CONCLUSIONS

FDEIA was far less common in elementary school than in junior-high school, and wheat was the major causative food. The new appearance of DEIA was notable. Decreasing episode recurrence remains an issue that needs to be resolved.

Assessment of the Allergenic Potential of the Main Egg White Proteins in BALB/c Mice

This work aimed to assess the contribution of the major egg white proteins, ovalbumin, ovomucoid, and lysozyme, to the induction and elicitation of allergenic responses. For this purpose, BALB/c mice were orally administered either the individual egg allergens or a mixture of the three proteins in the same proportion, to evaluate their relative allergenicity avoiding their different abundance in egg white. Cholera toxin was used as a T helper 2 (Th2)-polarizing adjuvant. Ovomucoid and lysozyme triggered the most severe anaphylaxis reactions upon oral challenge. In comparison to ovalbumin and ovomucoid, lysozyme was a more active promotor of early immunoglobulin E and immunoglobulin G1 production and stimulated stronger Th2-biased responses from both mesenteric lymph node and spleen cells. These results indicate that lysozyme is highly immunogenic and should be considered as a major allergen, whose clinical usefulness in the diagnosis, prognosis, and therapeutic approaches of egg allergy deserves further consideration.

Efficacy and Safety of AR101 in Oral Immunotherapy for Peanut Allergy: Results of ARC001, a Randomized, Double-Blind, Placebo-Controlled Phase 2 Clinical Trial

BACKGROUND

Peanut oral immunotherapy, using a variety of approaches, has been previously shown to induce desensitization in peanut-allergic subjects, but no products have been approved for clinical use by regulatory agencies.

OBJECTIVE

We performed the first phase 2 multicentered study to assess the safety and efficacy of AR101, a novel oral biologic drug product.

METHODS

A randomized, double-blind, placebo-controlled trial was conducted at 8 US centers. Eligible subjects were 4 to 26 years old, sensitized to peanut, and had dose-limiting symptoms to ≤143 mg of peanut protein in a screening double-blind, placebo-controlled food challenge (DBPCFC). Subjects were randomized 1:1 to daily AR101 or placebo and gradually up-dosed from 0.5 to 300 mg/day. The primary endpoint was the proportion of subjects in each arm able to tolerate ≥443 mg (cumulative peanut protein) at exit DBPCFC with no or mild symptoms.

RESULTS

Fifty-five subjects (29 AR101, 26 placebo) were enrolled. In the intention-to-treat analysis, 23 of 29 (79%) and 18 of 29 (62%) AR101 subjects tolerated ≥443 mg and 1043 mg at exit DBPCFC, respectively, versus 5 of 26 (19%) and 0 of 26 (0%) placebo subjects (both P < .0001). Compared with placebo, AR101 significantly reduced symptom severity during exit DBPCFCs and modulated peanut-specific cellular and humoral immune responses. Gastrointestinal (GI) symptoms were the most common treatment-related adverse events (AEs) in both groups, with 6 AR101 subjects (21%) withdrawing, 4 of those due primarily to recurrent GI AEs.

CONCLUSIONS

In this study, AR101 demonstrated an acceptable safety profile and demonstrated clinical activity as a potential immunomodulatory treatment option in peanut-allergic children over the age of 4, adolescents, and young adults.

Current Status of Potential Therapies for IgE-Mediated Food Allergy

PURPOSE OF REVIEW

The goal of this review is to provide the reader with an updated summary of published trial data regarding the use of oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) for treatment of IgE-mediated food allergies.

RECENT FINDINGS

Data from phase 2 trials for treatment of peanut allergy with OIT and EPIT reveal an increase in the threshold of reactivity for peanut-allergic children. Compared to EPIT, OIT promotes a greater increase in the threshold of reactivity; however, adverse events are more common with OIT. OIT, EPIT, and SLIT appear to modulate the immune response for some food-allergic individuals. Data regarding utility for treatment of food allergies regardless of modality is limited to few foods, as is investigation into treatment of food-allergic infants, young children, and adults. Future trials are likely to focus on young children, food allergies other than peanut, and treatment of multifood-allergic individuals.

Antibody Profile of Colostrum and the Effect of Processing in Human Milk Banks: Implications in Immunoregulatory Properties

BACKGROUND

When feeding preterm infants, donor milk is preferred if the mother's own milk is unavailable. Pasteurization may have detrimental effects on bioactivity, but more information is needed about its effects on the immunological compounds. Research aim: This work has two main aims: evaluate the antibody profile of colostrum and study the quantitative variations in the antibodies' level and specific reactivity after undergoing Holder pasteurization. The authors focused on immunoregulatory components of colostrum (antidietary antibodies and TGF-β2) in the neonatal gut.

METHODS

This is a descriptive cross-sectional study of a convenience sample of 67 donated colostrum samples at different days after delivery, both raw and pasteurized. Antibody profiles were analyzed at different times during breastfeeding, and total and specific antibodies (IgM, IgA, and IgG subclasses) were compared with tetanus toxoid and ovalbumin using enzyme-linked immunosorbent assay. The processing effect on total and specific antibodies, as well as TGF-β2, was evaluated by paired analyses.

RESULTS

No variations in immunological compounds were observed throughout the colostrum stage. The TGF-β2, antibodies' concentrations, and antibodies' specific reactivity after pasteurization did not vary significantly as days of lactation varied. Changes in antibody levels were dependent on isotype and IgG subclass, and IgG4 showed remarkable resistance to heating. Moreover, the effect of the pasteurization on specific reactivity was antigen dependent.

CONCLUSION

The supply of relevant immunological components is stable throughout the colostrum stage. The effects of pasteurization on antibodies depend on isotype, subclass, and specificity. This information is relevant to improving the immunological quality of colostrum, especially for preterm newborns.

Novel immunotherapy and treatment modality for severe food allergies

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Use of biologics in severe food allergies

PURPOSE OF REVIEW

Severe cases of food allergy account for the majority of the burden in terms of risks, quality of life, and resource expenditure. The traditional approach to these forms has been strict avoidance. More recently, Oral ImmunoTherapy (OIT) has gained a role in their management. However, in severe food allergies OIT is often infeasible.

RECENT FINDINGS

Case reports, observational, and prospective studies have recently proposed different approaches to severe food allergy. The majority of them include the use of biologics. Omalizumab has been the most studied drug for severe food allergies, and its role as adjuvant treatment to OIT is well established. Interest has been raised on other biologics, as dupilumab, reslizumab, and mepolizumab. Toll-like receptor agonists, and gene therapy using adeno-associated virus coding for Omalizumab are promising alternatives.

SUMMARY

The recent studies are deeply influencing the clinical practice. We review the modifications of the clinical approach to severe food allergies so far available. We indicate the possible evolutions of treatment with biologics in severe food allergies.

Allergen-Specific Immunotherapies for Food Allergy

With rising prevalence of food allergy (FA), allergen-specific immunotherapy (AIT) for FA has become an active area of research in recent years. In AIT, incrementally increasing doses of inciting allergen are given with the goal to increase tolerance, initially through desensitization, which relies on regular exposure to allergen. With prolonged therapy in some subjects, AIT may induce sustained unresponsiveness, in which tolerance is retained after a period of allergen avoidance. Methods of AIT currently under study in humans include oral, sublingual, epicutaneous, and subcutaneous delivery of modified allergenic protein, as well as via DNA-based vaccines encoding allergen with lysosomal-associated membrane protein I. The balance of safety and efficacy varies by type of AIT, as well as by targeted allergen. Age, degree of sensitization, and other comorbidities may affect this balance within an individual patient. More recently, AIT with modified proteins or combined with immunomodulatory therapies has shown promise in making AIT safer and/or more effective. Though methods of AIT are neither currently advised by experts (oral immunotherapy [OIT]) nor widely available, AIT is likely to become a part of recommended management of FA in the coming years. Here, we review and compare methods of AIT currently under study in humans to prepare the practitioner for an exciting new phase in the care of food allergic patients in which improved tolerance to inciting foods will be a real possibility.

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.

Observational long-term follow-up study of rapid food oral immunotherapy with omalizumab

Background

A number of clinical studies focused on treating a single food allergy through oral immunotherapy (OIT) with adjunctive omalizumab treatment have been published. We previously demonstrated safety and tolerability of a rapid OIT protocol using omalizumab in a phase 1 study to achieve desensitization to multiple (up to 5) food allergens in parallel, rapidly (7–36 weeks; median = 18 weeks). In the current long-term, observational study, we followed 34 food allergic participants for over 5 years, who had originally undergone the phase 1 rapid OIT protocol.

Methods

After reaching the maintenance dose of 2 g protein for each of their respective food allergens as a part of the phase 1 study, the long-term maintenance dose was reduced for some participants based on a pragmatic team-based decision. Participants were followed up to 62 months through standard oral food challenges (OFCs), skin prick tests, and blood tests.

Results

Each participant passed the 2 g OFC to each of their offending food allergens (up to 5 food allergens in total) at the end of the long-term follow-up (LTFU) study.

Conclusion

Our data demonstrate the feasibility of long-term maintenance dosing of a food allergen without compromising the desensitized status conferred through rapid-OIT.

Trial registration Registry: Clinicaltrials.gov. Registration numbers: NCT01510626 (original study), NCT03234764 (LTFU study). Date of registration: November 29, 2011 (original study); July 26, 2017 (LTFU study, retrospectively registered)

Electronic supplementary material

The online version of this article (10.1186/s13223-017-0223-8) contains supplementary material, which is available to authorized users.

Anti-IgE treatment with oral immunotherapy in multifood allergic participants: a double-blind, randomised, controlled trial

BACKGROUND

Despite progress in single food oral immunotherapy (OIT), there is little evidence concerning the safety and efficacy of treating individuals with multiple food (multifood) allergies. We conducted a pilot study testing whether anti-IgE (omalizumab) combined with multifood OIT benefitted multifood allergic patients.

METHODS

In this blinded, phase 2 clinical trial conducted at Stanford University, 48 participants, aged 4-15 years, with multifood allergies validated by double-blind, placebo-controlled food challenges (DBPCFCs) to their offending foods were block randomized (3:1) to receive multifood OIT to 2-5 foods, together with omalizumab (n=36) or placebo (n=12). Omalizumab or placebo was administered subcutaneously for 16 weeks with OIT starting at week 8; omalizumab or placebo was stopped 20 weeks before exit DBPCFCs (week 36) to determine the primary endpoint: the proportion of participants who passed DBPCFCs to at least 2 of their offending foods. This completed trial is registered with ClinicalTrials.gov, .

FINDINGS

At week 36, a significantly greater proportion of the omalizumab (30/36, 83%) vs. placebo (4/12, 33%) participants passed DBPCFCs to 2 g protein for ≥ 2 of their offending foods (odds ratio (OR): 10, 95% confidence interval (CI): 1·8, 58·3, P=0·004). The same individuals also tolerated 4 g protein of ≥ 2 foods (secondary endpoint, P=0·004). A greater proportion of omalizumab (13/17, 77%) vs. placebo (0/5, 0%) participants passed a DBPCFC to 2 g protein for ≥ 4 of their offending foods (OR: 33, 95% CI: 1·9, ∞, P=0·01). All participants completed the study. There were no serious or severe (≥ grade 3) adverse events.

INTERPRETATION

In multifood allergic patients, omalizumab improves the efficacy of multifood OIT and enables safe and rapid desensitization.

FUNDING

NIH U19 AADCRC and Opportunity Fund, Sean N. Parker Center for Allergy and Asthma Research at Stanford University, Simons Foundation, Myra Reinhard Foundation, FARE Center of Excellence, Department of Pathology, and Department of Pediatrics, Stanford University.

Integrative transcriptomic analysis reveals key drivers of acute peanut allergic reactions

Mechanisms driving acute food allergic reactions have not been fully characterized. We profile the dynamic transcriptome of acute peanut allergic reactions using serial peripheral blood samples obtained from 19 children before, during, and after randomized, double-blind, placebo-controlled oral challenges to peanut. We identify genes with changes in expression triggered by peanut, but not placebo, during acute peanut allergic reactions. Network analysis reveals that these genes comprise coexpression networks for acute-phase response and pro-inflammatory processes. Key driver analysis identifies six genes (LTB4R, PADI4, IL1R2, PPP1R3D, KLHL2, and ECHDC3) predicted to causally modulate the state of coregulated networks in response to peanut. Leukocyte deconvolution analysis identifies changes in neutrophil, naive CD4+ T cell, and macrophage populations during peanut challenge. Analyses in 21 additional peanut allergic subjects replicate major findings. These results highlight key genes, biological processes, and cell types that can be targeted for mechanistic study and therapeutic targeting of peanut allergy.

What Is Wrong with Pertussis Vaccine Immunity? Why Immunological Memory to Pertussis Is Failing

Memory responses seen after whole-cell pertussis (wP) and acellular pertussis (aP) vaccine priming are different and reflect better long-term protection against pertussis disease seen with the whole-cell vaccines. Although acellular vaccines generate higher levels of antigen-specific IgG to the antigens included in the aP vaccines, there are many more pertussis antigens included in whole-cell vaccines. Acellular vaccine priming is associated with skewing of the immune response to a more Th2-like response, whereas whole-cell priming is associated with a Th1/Th17 response. Repeated booster doses of acellular vaccine in children primed with acellular vaccine has been shown to result in progressively shorter duration of protection against disease. This may be explained by the generation of higher levels of antigen-specific IgG4, which does not bind complement and leads to a suboptimal inflammatory response and impaired phagocytosis and antimicrobial defense. In contrast, whole-cell priming followed by aP vaccine boosters results in better opsonization, phagocytosis, and complement mediated killing through the preferential induction of IgG1.

Introduction of various allergenic foods during infancy reduces risk of IgE sensitization at 12 months of age: a birth cohort study

BackgroundIn this study, we aimed to determine whether introducing various allergenic foods during infancy is associated with IgE sensitization at 12 months of age.MethodsDetailed information on feeding practices regarding six possible allergenic foods (fruits, egg white, egg yolk, fish, shellfish, and peanuts) was obtained by administering age-specific questionnaires to parents of infants at ages 6 and 12 months. Fecal secretory IgA (sIgA), fecal eosinophil cationic protein (ECP), and serum levels of total IgE and IgE specific to 20 foods, and IgE specific to 20 inhalant allergens were also quantified at 12 months of age.ResultsAt 12 months of age, infants with IgE sensitization had been introduced to fewer allergenic food items during infancy (3.2±1.4 vs. 3.7±1.3 items). Compared with infants who were given 0-2 allergenic food items, infants introduced to 3-4 or ≥5 allergenic food items showed a significantly lower risk of IgE sensitization (odds ratios (ORs) 0.62 and 0.61, respectively) and lower total IgE levels. In addition, non-introduction of egg white or egg yolk was significantly related to IgE sensitization (ORs 1.41 and 1.26, respectively).ConclusionIncreasing the diversity of allergenic foods in infancy, including fruits, egg white, egg yolk, fish, shellfish, and peanuts, may protect infants from IgE sensitization at 12 months of age.

The current state of food allergy therapeutics

The prevalence of IgE mediated food allergy is an increasing public health concern. The current standard of treatment is strict avoidance of the offending food(s). There are no FDA approved treatments for food allergy. This review will provide an overview of strategies currently under investigation for the treatment of food allergy. The main focus of research has been directed at various forms of immunotherapy, including oral, sublingual and epicutaneous delivery routes. While oral immunotherapy (OIT) has shown the greatest promise for efficacy in terms of amount of protein that can be ingested, it has also demonstrated less tolerability and a less favorable safety profile as compared to sublingual immunotherapy (SLIT) and epicutaneous immunotherapy (EPIT), which offers the least protection but has the best safety and tolerability profile. Investigation is also underway for modified antigens that may be used for immunotherapy and for adjuncts that may help facilitate immunotherapy, including biologics such as anti-IgE therapy, and also probiotics. There are also a number of preclinical concepts that are being evaluated to manipulate the antigens and/or the immune system that may one day be translatable to patients.

Patient-Centered Outcomes in Food Allergy

PURPOSE OF REVIEW

Food allergy prevalence is increasing very rapidly, causing a significant disease burden. The threat of severe allergic reactions occurring unexpectedly and in settings that are not equipped to recognize and treat anaphylaxis is a constant source of worry for individuals and families with food allergies. Inadequate knowledge and understanding in the community significantly impairs the overall quality of life of these individuals and families. Additionally, families face challenges in finding and affording appropriate allergen-free foods.

RECENT FINDINGS

Advancements have been made in understanding the impact of food allergies on patient-centered outcomes such as quality of life and economic impact, and attempts have been made to develop tools to assess patient-centered variables. Innovative national and regional initiatives are helping to spread awareness of the disease condition and to create resources, including access to allergen-free foods. While there is a growing momentum toward recognition of food allergic disorders as a condition that profoundly impacts activities of daily living, greater effort needs to be expounded to develop validated tools and interventions that can adequately address these issues.

Oral immunotherapy in children with IgE-mediated hen's egg allergy: Follow-ups at 2.5 and 7 years

Background:

The present report was a follow-up investigation at 2.5- and 7-year intervals of a previous study of 20 children with moderate-to-severe immunoglobulin E (IgE) mediated hen's egg (HE) allergy who received oral immunotherapy (OIT) with raw HE. The study design of the previous study divided the 20 subjects into two groups of 10 each: (1) group 1, the OIT group (OIT-G), and, (2) group 2, an age-matched control group (C-G). In that study, 8 of 10 of the children in the OIT-G were successfully desensitized, one child was partially desensitized, and desensitization failed in one child. The aims of the present study were to evaluate the long-term effectiveness and safety profile of OIT with raw HE, and to assess the course and prognostic value of skin-prick tests (SPT) and serum-specific HE-IgEs in this study population.

Methods:

Of the 20 children who were recalled, 2 dropped out, which left 18 to be evaluated. Information on their HE intake was recorded, and SPTs with HE allergen extracts and with raw and hard-boiled HE were performed. Ovomucoid- and ovalbumin-specific IgE levels were also measured.

Results:

At the first (2.5-year) and second (7-year) follow-ups, 87.5% of the children in the OIT-G who tolerated raw HE were still tolerant, whereas the children in the C-G were significantly less tolerant. Overall, cutaneous sensitivity to HE significantly decreased after the 6-month desensitization period and at both follow-ups with regard to the OIT-G but not with regard to the C-G. A significant reduction in serum ovomucoid- and ovalbumin-specific IgE levels was seen in both the OIT-G and the C-G.

Conclusion:

Clinical raw HE tolerance induced by OIT persists over time. Negativization of SPTs could be considered a more reliable prognostic indicator of clinical tolerance to raw HE than the reduction in specific-HE IgE levels. Raw-HE OIT would seem to be a promising method to treat HE allergy.

The efficacy of oral and subcutaneous antigen-specific immunotherapy in murine cow's milk- and peanut allergy models

BACKGROUND

Antigen-specific immunotherapy (AIT) is a promising therapeutic approach for both cow's milk allergy (CMA) and peanut allergy (PNA), but needs optimization in terms of efficacy and safety.

AIM

Compare oral immunotherapy (OIT) and subcutaneous immunotherapy (SCIT) in murine models for CMA and PNA and determine the dose of allergen needed to effectively modify parameters of allergy.

METHODS

Female C3H/HeOuJ mice were sensitized intragastrically (i.g.) to whey or peanut extract with cholera toxin. Mice were treated orally (5 times/week) or subcutaneously (3 times/week) for three consecutive weeks. Hereafter, the acute allergic skin response, anaphylactic shock symptoms and body temperature were measured upon intradermal (i.d.) and intraperitoneal (i.p.) challenge, and mast cell degranulation was measured upon i.g. challenge. Allergen-specific IgE, IgG1 and IgG2a were measured in serum at different time points. Single cell suspensions derived from lymph organs were stimulated with allergen to induce cytokine production and T cell phenotypes were assessed using flow cytometry.

RESULTS

Both OIT and SCIT decreased clinically related signs upon challenge in the CMA and PNA model. Interestingly, a rise in allergen-specific IgE was observed during immunotherapy, hereafter, treated mice were protected against the increase in IgE caused by allergen challenge. Allergen-specific IgG1 and IgG2a increased due to both types of AIT. In the CMA model, SCIT and OIT reduced the percentage of activated Th2 cells and increased the percentage of activated Th1 cells in the spleen. OIT increased the percentage of regulatory T cells (Tregs) and activated Th2 cells in the MLN. Th2 cytokines IL-5, IL-13 and IL-10 were reduced after OIT, but not after SCIT. In the PNA model, no differences were observed in percentages of T cell subsets. SCIT induced Th2 cytokines IL-5 and IL-10, whereas OIT had no effect.

CONCLUSION

We have shown clinical protection against allergic manifestations after OIT and SCIT in a CMA and PNA model. Although similar allergen-specific antibody patterns were observed, differences in T cell and cytokine responses were shown. Whether these findings are related to a different mechanism of AIT in CMA and PNA needs to be elucidated.

Advances and highlights in allergen immunotherapy: On the way to sustained clinical and immunologic tolerance

Allergen immunotherapy (AIT) is an effective treatment strategy for allergic diseases and has been used for more than 100 years. In recent years, however, the expectations on concepts, conduct, statistical evaluation, and reporting have developed significantly. Products have undergone dose-response and confirmative studies in adults and children to provide evidence for the optimal dosage, safety, and efficacy of AIT vaccines using subcutaneous and sublingual delivery pathways in large patient cohorts, ensuring solid conclusions to be drawn from them for the advantage of patients and societies alike. Those standards should be followed today, and products answering to them should be preferred over others lacking optimization and proof of efficacy and safety. Molecular and cellular mechanisms of AIT include early mast cell and basophil desensitization effects, regulation of T- and B-cell responses, regulation of IgE and IgG₄ production, and inhibition of responses from eosinophils, mast cells, and basophils in the affected tissues. There were many developments to improve vaccination strategies, demonstration of new molecules involved in molecular mechanisms, and demonstration of new biomarkers for AIT during the last few years. The combination of probiotics, vitamins, and biological agents with AIT is highlighting current advances. Development of allergoids and recombinant and hypoallergenic vaccines to skew the immune response from IgE to IgG₄ and regulation of dendritic cell, mast cell, basophil, innate lymphoid cell, T-cell, and B-cell responses to allergens are also discussed in detail.

Immune monitoring for precision medicine in allergy and asthma

'Precision Medicine' embodies the analyses of extensive data collected from patients and their environments to identify and apply patient-specific prophylactic strategies and medical treatments to improve clinical outcomes and healthcare cost-effectiveness. Many new methods have been developed for evaluating the activity of the human immune system. Such 'immune monitoring' approaches are now being used in studies of allergy and asthma in the hope of identifying better correlates of disease status, predictors of therapeutic outcomes, and potential side-effects of treatment. Together with analyses of family histories, genetic and other biometric data, and measurements of exposures to environmental and other risk factors for developing or exacerbating disease, immune monitoring approaches promise to enable 'Precision Medicine' for allergic diseases and asthma.