Oral immunotherapy for treatment of egg allergy in children

A pilot study of omalizumab to facilitate rapid oral desensitization in high-risk peanut-allergic patients

BACKGROUND

Peanut allergy is a major public health problem that affects 1% of the population and has no effective therapy.

OBJECTIVE

To examine the safety and efficacy of oral desensitization in peanut-allergic children in combination with a brief course of anti-IgE mAb (omalizumab [Xolair]).

METHODS

We performed oral peanut desensitization in peanut-allergic children at high risk for developing significant peanut-induced allergic reactions. Omalizumab was administered before and during oral peanut desensitization.

RESULTS

We enrolled 13 children (median age, 10 years), with a median peanut-specific IgE level of 229 kU(A)/L and a median total serum IgE level of 621 kU/L, who failed an initial double-blind placebo-controlled food challenge at peanut flour doses of 100 mg or less. After pretreatment with omalizumab, all 13 subjects tolerated the initial 11 desensitization doses given on the first day, including the maximum dose of 500 mg peanut flour (cumulative dose, 992 mg, equivalent to >2 peanuts), requiring minimal or no rescue therapy. Twelve subjects then reached the maximum maintenance dose of 4000 mg peanut flour per day in a median time of 8 weeks, at which point omalizumab was discontinued. All 12 subjects continued on 4000 mg peanut flour per day and subsequently tolerated a challenge with 8000 mg peanut flour (equivalent to about 20 peanuts), or 160 to 400 times the dose tolerated before desensitization. During the study, 6 of the 13 subjects experienced mild or no allergic reactions, 5 subjects had grade 2 reactions, and 2 subjects had grade 3 reactions, all of which responded rapidly to treatment.

CONCLUSIONS

Among children with high-risk peanut allergy, treatment with omalizumab may facilitate rapid oral desensitization and qualitatively improve the desensitization process.

World Allergy Organization Anaphylaxis Guidelines: 2013 update of the evidence base

The World Allergy Organization (WAO) Guidelines for the assessment and management of anaphylaxis are a widely disseminated and used resource for information about anaphylaxis. They focus on patients at risk, triggers, clinical diagnosis, treatment in health care settings, self-treatment in the community, and prevention of recurrences. Their unique strengths include a global perspective informed by prior research on the global availability of essentials for anaphylaxis assessment and management and a global agenda for anaphylaxis research. Additionally, detailed colored illustrations are linked to key concepts in the text [Simons et al.: J Allergy Clin Immunol 2011;127:593.e1-e22]. The recommendations in the original WAO Anaphylaxis Guidelines for management of anaphylaxis in health care settings and community settings were based on evidence published in peer-reviewed, indexed medical journals to the end of 2010. These recommendations remain unchanged and clinically relevant. An update of the evidence base was published in 2012 [Simons et al.: Curr Opin Allergy Clin Immunol 2012;12:389-399]. In 2012 and early 2013, major advances were reported in the following areas: further characterization of patient phenotypes; development of in vitro tests (for some allergens) that help distinguish clinical risk of anaphylaxis from asymptomatic sensitization; epinephrine (adrenaline) research, including studies of a new epinephrine auto-injector for use in community settings, and randomized controlled trials of immunotherapy to prevent food-induced anaphylaxis. Despite these advances, the need for additional prospective studies, including randomized controlled trials of interventions in anaphylaxis is increasingly apparent. This 2013 Update highlights publications from 2012 and 2013 that further contribute to the evidence base for the recommendations made in the original WAO Anaphylaxis Guidelines. Ideally, it should be used in conjunction with these Guidelines and with the 2012 Guidelines Update.

Food allergy diagnosis and therapy: where are we now?

Food allergy is a growing worldwide epidemic that adversely effects up to 10% of the population. Causes and risk factors remain unclear and diagnostic methods are imprecise. There is currently no accepted treatment for food allergy. Therefore, there is an imminent need for greater understanding of food allergies, revised diagnostics and development of safe, effective therapies. Oral immunotherapy provides a particularly promising avenue, but is still highly experimental and not ready for clinical use.

Oral immunotherapy and tolerance induction in childhood

Prevalence rates of food allergy have increased rapidly in recent decades. Of concern, rates of increase are greatest among children under 5 yrs of age and for those food allergies that persist into adulthood such as peanut or tree nut allergy and shellfish allergy. Given these trends, the overall prevalence of food allergy will compound over time as the number of children affected by food allergy soars and a greater proportion of food-allergic children are left with persistent disease into adulthood. It is therefore vital to identify novel curative treatment approaches for food allergy. Acquisition of oral tolerance to the diverse array of ingested food antigens and intestinal microbiota is an active immunologic process that is successfully established in the majority of individuals. In subjects who develop food allergy, there is a failure or loss of oral tolerance acquisition to a limited number of food allergens. Oral immunotherapy (OIT) offers a promising approach to induce specific oral tolerance to selected food allergens and represents a potential strategy for long-term curative treatment of food allergy. This review will summarize the current understanding of oral tolerance and clinical trials of OIT for the treatment of food allergy.

Oral and sublingual immunotherapy for food allergy: current progress and future directions

Food allergies are increasing in prevalence and present an emerging epidemic for westernized countries. Strict dietary avoidance is the only approved management for food allergy, but accidental exposures regularly occur, leading to significant patient anxiety and decreased quality of life. Over the past decade, oral and sublingual immunotherapies have emerged as potential treatments for food allergy. While several small clinical trials have demonstrated that immunotherapy can desensitize food-allergic individuals, strategies for further enhancing safety and definitively establishing long-term efficacy are needed. This review presents an overview of recent oral and sublingual immunotherapy trials, and provides a glimpse into what the next generation of food immunotherapy may entail.

Effectiveness and safety of orally administered immunotherapy for food allergies: a systematic review and meta-analysis

The aim of using oral and sublingual immunotherapy with food allergies is to enable the safe consumption of foods containing these allergens in patients with food allergies. In the present study, a systematic review of intervention studies was undertaken; this involved the searching of eleven international databases for controlled clinical trials. We identified 1152 potentially relevant papers, from which we selected twenty-two reports of twenty-one eligible trials (i.e. eighteen randomised controlled trials and three controlled clinical trials). The meta-analysis revealed a substantially lower risk of reactions to the relevant food allergen in those receiving orally administered immunotherapy (risk ratios (RR) 0·21, 95 % CI 0·12, 0·38). The meta-analysis of immunological data demonstrated that skin prick test responses to the relevant food allergen significantly decreased with immunotherapy (mean difference - 2·96 mm, 95 % CI - 4·48, - 1·45), while allergen-specific IgG4 levels increased by an average of 19·9 (95 % CI 17·1, 22·6) μg/ml. Sensitivity analyses excluding studies at the highest risk of bias and subgroup analyses in relation to specific food allergens and treatment approaches generated comparable summary estimates of effectiveness and immunological changes. Pooling of the safety data revealed an increased risk of local (i.e. minor oropharyngeal/gastrointestinal) adverse reactions with immunotherapy (RR 1·47, 95 % CI 1·11, 1·95); there was a non-significant increased average risk of systemic adverse reactions with immunotherapy (RR 1·08, 95 % CI 0·97, 1·19). There is strong evidence that orally administered immunotherapy can induce immunomodulatory changes and thereby promote desensitisation to a range of foods. However, given the paucity of evidence on longer-term safety, effectiveness and cost-effectiveness, orally administered immunotherapy should not be used outside experimental conditions presently.

Therapeutic opportunities for manipulating T(Reg) cells in autoimmunity and cancer

Forkhead box P3 (FOXP3)-expressing regulatory T (T(Reg)) cells have a pivotal role in the regulation of immune responses and in the maintenance of immunological self-tolerance. These cells have emerged as attractive targets for strategies that allow the steering of immune responses in desired directions - arming the immune system to destroy infected cells and cancer cells or downregulating it to limit tissue destruction in autoimmunity. Efforts to understand the generation, activation and function of T(Reg) cells should permit the development of therapeutics for reprogramming the immune system. In this Review, we discuss insights into the generation of T(Reg) cells, their involvement in disease and the molecular basis of the dominant tolerance exerted by FOXP3(+) T(Reg) cells that could permit their safe and specific manipulation in humans.

Food allergy: management, diagnosis and treatment strategies

Food allergy is an increasing problem in western countries, with strict avoidance being the only available reliable treatment. However, accidental ingestion can occur and anaphylactic reactions still happen. In recent years, many efforts have been made to better understand the humoral and cellular mechanisms involved in food allergy, and to improve the strategies for diagnosis and treatment. This review focuses on IgE-mediated food hypersensitivity and provides an overview of the diagnostic strategies and treatment advances. Specific immunotherapy, including different routes of administration and allergen sources, such as natural, recombinant and T-cell epitopes, are analyzed in detail. Other treatments such as anti-IgE monoclonal antibody therapy, adjuvant therapy and Chinese herbs will also be described.

Early regular egg exposure in infants with eczema: A randomized controlled trial

BACKGROUND

Observational studies suggest that early regular ingestion of allergenic foods might reduce the risk of food allergy.

OBJECTIVE

We sought to determine whether early regular oral egg exposure will reduce subsequent IgE-mediated egg allergy in infants with moderate-to-severe eczema.

METHODS

In a double-blind, randomized controlled trial infants were allocated to 1 teaspoon of pasteurized raw whole egg powder (n = 49) or rice powder (n = 37) daily from 4 to 8 months of age. Cooked egg was introduced to both groups after an observed feed at 8 months. The primary outcome was IgE-mediated egg allergy at 12 months, as defined based on the results of an observed pasteurized raw egg challenge and skin prick tests.

RESULTS

A high proportion (31% [15/49]) of infants randomized to receive egg had an allergic reaction to the egg powder and did not continue powder ingestion. At 4 months of age, before any known egg ingestion, 36% (24/67) of infants already had egg-specific IgE levels of greater than 0.35 kilounits of antibody (kUA)/L. At 12 months, a lower (but not significant) proportion of infants in the egg group (33%) were given a diagnosis of IgE-mediated egg allergy compared with the control group (51%; relative risk, 0.65; 95% CI, 0.38-1.11; P = .11). Egg-specific IgG4 levels were significantly (P < .001) greater in the egg group at both 8 and 12 months.

CONCLUSION

Induction of immune tolerance pathways and reduction in egg allergy incidence can be achieved by early regular oral egg exposure in infants with eczema. Caution needs to be taken when these high-risk infants are first exposed to egg because many have sensitization already by 4 months of age.

Oral immunotherapy for food allergy: clinical and preclinical studies

Food allergies affect approximately 5% of the U.S. population and have increased in the last decade. In recent years, oral immunotherapy (OIT) has been tested in clinical trials for peanut, milk, and egg allergies in young children. OIT appears to be fairly well tolerated by most subjects and leads to desensitization with a greatly increased threshold of allergen required to induce reactions. Further approaches being investigated in preclinical studies in mouse models indicate the potential for using adjuvants, such as TLR9 agonists in combination with OIT; peptide OIT; and non-allergen specific applications such as herbal formulations. Further questions about OIT remain, including the optimal dosing and length of treatment; whether tolerance can be developed; and the exact cellular mechanisms resulting in protection following OIT. With many clinical trials underway across the United States and other countries, and a growing pipeline of preclinical research with translational potential, there is great hope for a widely applicable food allergy treatment.

Mechanism of oral tolerance induction to therapeutic proteins

Oral tolerance is defined as the specific suppression of humoral and/or cellular immune responses to an antigen by administration of the same antigen through the oral route. Due to its absence of toxicity, easy administration, and antigen specificity, oral tolerance is a very attractive approach to prevent unwanted immune responses that cause a variety of diseases or that complicate treatment of a disease. Many researchers have induced oral tolerance to efficiently treat autoimmune and inflammatory diseases in different animal models. However, clinical trials yielded limited success. Thus, understanding the mechanisms of oral tolerance induction to therapeutic proteins is critical for paving the way for clinical development of oral tolerance protocols. This review will summarize progress on understanding the major underlying tolerance mechanisms and contributors, including antigen presenting cells, regulatory T cells, cytokines, and signaling pathways. Potential applications, examples for therapeutic proteins and disease targets, and recent developments in delivery methods are discussed.

Heated allergens and induction of tolerance in food allergic children

Food allergies are one of the first manifestations of allergic disease and have been shown to significantly impact on general health perception, parental emotional distress and family activities. It is estimated that in the Western world, almost one in ten children have an IgE-mediated allergy. Cow's milk and egg allergy are common childhood allergies. Until recently, children with food allergy were advised to avoid all dietary exposure to the allergen to which they were sensitive, in the thought that consumption would exacerbate their allergy. However, recent publications indicate that up to 70% of children with egg allergy can tolerate egg baked in a cake or muffin without apparent reaction. Likewise, up to 75% of children can tolerate baked goods containing cow's milk, and these children demonstrate IgE and IgG4 profiles indicative of tolerance development. This article will review the current literature regarding the use of heated food allergens as immunotherapy for children with cow's milk and egg allergy.

Potential therapies for food allergy: a review

Food allergy is a widespread problem that has been increasing in prevalence in recent years. Avoidance of food allergens is difficult. Food allergic reactions are common and can be severe. Unfortunately, there is little in the way of therapies for food allergy, and strict allergen avoidance remains the standard of care. Several therapeutic approaches are currently being investigated, including subcutaneous, oral, and sublingual immunotherapy, anti-immunoglobulin E therapy, and traditional Chinese medicine. Although results thus far show promise for several of these strategies, further studies are needed to evaluate the safety, efficacy, and long-term outcomes before any food allergy therapies currently under investigation are ready for widespread use in clinical practice.

A phase 1 study of heat/phenol-killed, E. coli-encapsulated, recombinant modified peanut proteins Ara h 1, Ara h 2, and Ara h 3 (EMP-123) for the treatment of peanut allergy

BACKGROUND

Immunotherapy for peanut allergy may be limited by the risk of adverse reactions.

OBJECTIVE

To investigate the safety and immunologic effects of a vaccine containing modified peanut proteins.

METHODS

This was a phase 1 trial of EMP-123, a rectally administered suspension of recombinant Ara h 1, Ara h 2, and Ara h 3, modified by amino acid substitutions at major IgE-binding epitopes, encapsulated in heat/phenol-killed E. coli. Five healthy adults were treated with 4 weekly escalating doses after which 10 peanut-allergic adults received weekly dose escalations over 10 weeks from 10 mcg to 3063 mcg, followed by three biweekly doses of 3063 mcg.

RESULTS

There were no significant adverse effects in the healthy volunteers. Of the 10 peanut-allergic subjects [4 with intermittent asthma, median peanut IgE 33.3 kUA /l (7.2-120.2), and median peanut skin prick test wheal 11.3 mm (6.5-18)]; four experienced no symptoms; one had mild rectal symptoms; and the remaining five experienced adverse reactions preventing completion of dosing. Two were categorized as mild, but the remaining three were more severe, including one moderate reaction and two anaphylactic reactions. Baseline peanut IgE was significantly higher in the five reactive subjects (median 82.4 vs 17.2 kUA /l, P = 0.032), as was baseline anti-Ara h 2 IgE (43.3 versus 8.3, P = 0.036). Peanut skin test titration and basophil activation (at a single dilution) were significantly reduced after treatment, but no significant changes were detected for total IgE, peanut IgE, or peanut IgG4.

CONCLUSIONS

Rectal administration of EMP-123 resulted in frequent adverse reactions, including severe allergic reactions in 20%.

Comparison between two maintenance feeding regimens after successful cow's milk oral desensitization

BACKGROUND

Cow's milk allergy is common in infancy, and total avoidance of this food is the only effective approach. In alternative, oral immunotherapy has been proposed to achieve tolerance. Once desensitization is achieved, daily intake of milk is recommended to maintain it, but this may be impractical for children/parents. We assessed whether a twice weekly maintenance regimen is effective.

METHODS

Children who were successfully desensitized with oral immunotherapy were randomized to two maintenance regimens for 1 year: group A had to eat 150-200 ml milk daily, group B had to eat 150-200 ml milk twice weekly. Both regimens were associated to a totally free diet. Maintenance of tolerance and adverse events were recorded during 1 year. Specific IgE, IgG4 and prick-by-prick test to milk were carried out before immunotherapy (T0), before maintenance (T1), and after 1 year (T2).

RESULTS

Recorded episodes included asthma, oral itching, urticaria, rhinitis, abdominal pain variously combined, usually associated with concomitant illness or exercise. The episodes were 8 in group A and 9 in group B, with no difference. None of the children discontinued the feeding maintenance. Specific IgG4 increased at T1 and remained high at T2. Specific IgE and skin reactivity significantly decreased at T2. There was no difference in those parameters between the groups.

CONCLUSION

After achieving desensitization to cow milk with oral immunotherapy, a maintenance regimen with milk given twice weekly is as effective as the daily maintenance.

Childhood food allergies: current diagnosis, treatment, and management strategies

Food allergy is a growing public health concern in the United States that affects an estimated 8% of children. Food allergy is defined as an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a specific food. Nearly 40% of children with food allergy have a history of severe reactions that if not treated immediately with proper medication can lead to hospitalization or even death. The National Institute of Allergy and Infectious Diseases (NIAID) convened an expert panel in 2010 to develop guidelines outlining evidence-based practices in diagnosing and managing food allergy. The purpose of this review is to aid clinicians in translating the NIAID guidelines into primary care practice and includes the following content domains: (1) the definition and mechanism of childhood food allergy, (2) differences between food allergy and food intolerance, (3) the epidemiology of childhood food allergy in the United States, (4) best practices derived from the NIAID guidelines focused on primary care clinicians' management of childhood food allergy, (5) emerging food allergy treatments, and (6) future directions in food allergy research and practice. Articles focused on childhood food allergy were considered for inclusion in this review. Studies were restricted to the English language and to those published within the past 40 years. A cross-listed combination of the following words, phrases, and MeSH terms was searched in PubMed and Google Scholar to identify relevant articles: food allergy, food hypersensitivity, child, pediatric, prevalence, and epidemiology. Additional sources were identified through the bibliographies of the retrieved articles.

Dehydrated egg white: an allergen source for improving efficacy and safety in the diagnosis and treatment for egg allergy

BACKGROUND

Raw and cooked eggs are used as allergens in oral food challenge (OFC). Raw egg is the best option, as it keeps proteins intact and retains their allergenicity, albeit microbiologically safe manipulation is difficult. Therefore, the use of dehydrated egg white (DEW) could improve the efficacy and safety profile of OFC. The aim of the study was to compare the allergenicity of DEW, a product that undergoes a double heat treatment (pasteurization and drying), with that of raw egg white (REW) and determine the efficacy of DEW in the diagnosis of egg allergy.

METHODS

We conducted a prospective study of 40 egg-allergic patients who visited our outpatient clinic. Each patient underwent OFC with DEW and REW to determine the correlation between the tests. DEW and REW extracts were analyzed using SDS-PAGE. We compared the allergenicity of both extracts using IgE immunoblotting with a serum pool from patients with positive OFC results.

RESULTS

Ten patients (25%) had positive OFC results with both DEW and REW, and the doses that triggered an allergic reaction in each patient were similar (p > 0.05). All 30 patients (75%) with a negative OFC result with DEW also had negative OFC results with REW. SDS-PAGE and IgE immunoblotting revealed that the protein composition and IgE-binding capacity of both extracts were virtually identical.

CONCLUSIONS

This is the first time that it is shown that the allergenicity of commercially available DEW is equivalent to raw egg whites. In vivo and in vitro tests showed that processing of DEW does not affect the allergenicity of egg proteins. DEW is an effective and microbiologically safer source of allergen for the diagnosis of egg allergy. Furthermore, DEW can be used in egg oral immunotherapy.

Use of omalizumab in the treatment of food allergy and anaphylaxis

Omalizumab is a humanized monoclonal anti-IgE antibody that is currently FDA-approved for allergic asthma. Given its mechanism of action, recent reports have suggested its possible clinical use for food allergy and some forms of anaphylaxis. Omalizumab exerts its action by binding to circulating IgE, reducing IgE receptor expression, and decreasing mediator release from mast cells and basophils. Clinical trials using omalizumab in patients with food allergy resulted in achieving tolerance to higher amounts of the allergen in some patients. When used as an adjunct therapy during immunotherapy trials in patients with food allergy and anaphylaxis, omalizumab allowed more rapid and higher doses of immunotherapy to be given. Omalizumab has also been reported to be effective in a few patients with idiopathic anaphylaxis and mast cell disorders. Large multi-center trials are needed to confirm the above findings, and to identify subsets of patients that would benefit the most from omalizumab.

New directions in immunotherapy

Allergen immunotherapy (AIT) is effective in reducing the clinical symptoms associated with allergic rhinitis, asthma and venom-induced anaphylaxis. Subcutaneous (SCIT) and sublingual immunotherapy (SLIT) with unmodified allergen extracts are the most widely prescribed AIT regimens. The efficacy of these 2 routes appears comparable, but the safety profile with SLIT is more favorable allowing for home administration and requiring less patient time. However, both require that the treatment is taken regularly over several years, e.g., monthly in a supervised medical setting with SCIT and daily at home with SLIT. Despite the difference in treatment settings, poor adherence has been reported with both routes. Emerging evidence suggests that AIT may be effective in other allergic conditions such as atopic dermatitis, venom sting-induced large local reactions, and food allergy. Research with oral immunotherapy (OIT) for food allergies suggest that many patients can be desensitized during treatment, but questions remain about whether this can produce long term tolerance. Further studies are needed to identify appropriate patients and treatment regimens with these conditions. Efforts to develop safer and more effective AIT for inhalant allergies have led to investigations with modified allergens and alternate routes. Intralymphatic (ILIT) has been shown to produce long-lasting clinical benefits after three injections comparable to a 3-year course of SCIT. Epicutaneous (EPIT) has demonstrated promising results for food and inhalant allergies. Vaccine modifications, such as T cell epitopes or the use of viral-like particles as an adjuvant, have been shown to provide sustained clinical benefits after a relatively short course of treatment compared to the currently available AIT treatments, SLIT and SCIT. These newer approaches may increase the utilization and adherence to AIT because the multi-year treatment requirement of currently available AIT is a likely deterrent for initiating and adhering to treatment.

What's new in the diagnosis and management of food allergy in children?

This article reviews the recent advances in the diagnosis and management of IgE mediated food allergy in children. It will encompass the emerging technology of component testing; moves to standardization of the allergy food challenge; permissive diets which allow for inclusion of extensively heated food allergens with allergen avoidance; and strategies for accelerating tolerance and food desensitization including the use of adjuvants for specific tolerance induction.

Progress toward inducing immunologic tolerance to factor VIII

A major problem in treating hemophilia A patients with therapeutic factor VIII (FVIII) is that 20% to 30% of these patients produce neutralizing anti-FVIII antibodies. These antibodies block (inhibit) the procoagulant function of FVIII and thus are termed "inhibitors." The currently accepted clinical method to attempt to eliminate inhibitors is immune tolerance induction (ITI) via a protocol requiring intensive FVIII treatment until inhibitor titers drop. Although often successful, ITI is extremely costly and is less likely to succeed in patients with high-titer inhibitors. During the past decade, significant progress has been made in clarifying mechanisms of allo- and autoimmune responses to FVIII and in suppression of these responses. Animal model studies are suggesting novel, less costly methods to induce tolerance to FVIII. Complementary studies of anti-FVIII T-cell responses using blood samples from human donors are identifying immunodominant T-cell epitopes in FVIII and possible targets for tolerogenic efforts. Mechanistic experiments using human T-cell clones and lines are providing a clinically relevant counterpoint to the animal model studies. This review highlights recent progress toward the related goals of lowering the incidence of anti-FVIII immune responses and promoting durable, functional immune tolerance to FVIII in patients with an existing inhibitor.

Update on allergy immunotherapy: American Academy of Allergy, Asthma & Immunology/European Academy of Allergy and Clinical Immunology/PRACTALL consensus report

Allergy immunotherapy (AIT) is an effective treatment for allergic asthma and rhinitis, as well as venom-induced anaphylaxis. In addition to reducing symptoms, AIT can change the course of allergic disease and induce allergen-specific immune tolerance. In current clinical practice immunotherapy is delivered either subcutaneously or sublingually; some allergens, such as grass pollen, can be delivered through either route, whereas others, such as venoms, are only delivered subcutaneously. Both subcutaneous and sublingual immunotherapy appear to have a duration of efficacy of up to 12 years, and both can prevent the development of asthma and new allergen sensitivities. In spite of the advances with AIT, safer and more effective AIT strategies are needed, especially for patients with asthma, atopic dermatitis, or food allergy. Novel approaches to improve AIT include use of adjuvants or recombinant allergens and alternate routes of administration. As part of the PRACTALL initiatives, the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma & Immunology nominated an expert team to develop a comprehensive consensus report on the mechanisms of AIT and its use in clinical practice, as well as unmet needs and ongoing developments in AIT. This resulting report is endorsed by both academies.

Sublingual vs oral immunotherapy for food allergy: identifying the right approach

The incidence of food allergy in developed countries has increased in recent years, escalating the need to find a suitable form of treatment as an alternative to current management, which includes strict avoidance and ready availability of injectable epinephrine (adrenaline). Allergen immunotherapy is currently being studied for use in the treatment of IgE-mediated food allergy to the most common foods, including peanut, tree nut, milk and egg. Two modalities, oral immunotherapy (OIT) and sublingual immunotherapy (SLIT), have shown great promise. Both OIT and SLIT have been able to desensitize subjects to varying degrees, but the two treatment methods differ in doses that can be achieved, duration of treatment, safety profile and ease of use outside the research setting, among other aspects. More research is needed to conclude which mode of treatment is more effective in inducing long-term tolerance with the least amount of serious adverse reactions. However, OIT and SLIT show great promise, and a widespread treatment for food allergy may be within reach.

Can we produce true tolerance in patients with food allergy?

Immune tolerance is defined as nonresponsiveness of the adaptive immune system to antigens. Immune mechanisms preventing inappropriate immune reactivity to innocuous antigens include deletion of reactive lymphocytes and generation of regulatory T (Treg) cells. The normal response to food antigens is the generation of antigen-specific Treg cells. In patients with food allergy, the dominant immune response is a T(H)2-skewed T-cell response and the generation of food-specific IgE antibodies from B cells. It is not known whether a failure of the Treg cell response is behind this inappropriate immune response, but interventions that boost the Treg cell response, such as mucosal immunotherapy, might lead to a restoration of immune tolerance to foods. Tolerance has been notoriously difficult to restore in animal disease models, but limited data from human trials suggest that tolerance (sustained nonresponsiveness) can be re-established in a subset of patients. Furthermore, studies on the natural history of food allergy indicate that spontaneous development of tolerance to foods over time is not uncommon. The current challenge is to understand the mechanisms responsible for restoration of natural or induced tolerance so that interventions can be developed to more successfully induce tolerance in the majority of patients with food allergy.

Stromal plasma cells expressing immunoglobulin G4 subclass in non-small cell lung cancer

Inflammatory cell infiltration in tumor stroma may represent the interaction between the tumor and the immune system. The significance of immunoglobulin (Ig) G4+ plasmacytic infiltration, however, is poorly understood. Here, we analyzed the number of stromal IgG4+ plasma cells and the IgG4/IgG ratio of plasma cells in 294 primary non-small cell lung cancers (NSCLCs) using tissue microarray (TMA) and conventional surgical specimens. In TMA, 35 (12%) cases of NSCLC revealed more than 20 IgG4+ plasma cells per high-power field. In surgical specimens, most (97%) of those IgG4+ plasma cell-enriched cases showed obliterative phlebitis or arteritis, one of the key morphologic features of IgG4-related disease, within or at the periphery of the tumor. Clinically, none of the patients showed symptoms associated with IgG4-related systemic diseases. In patients with stage I squamous cell carcinoma, IgG4-enriched stroma was significantly associated with a favorable prognosis (P = .04). In conclusion, considerable IgG4+ plasma cell infiltration can be seen in a minority of cases of NSCLC and might contribute to prognostic modulation of NSCLC.

Sublingual immunotherapy for peanut allergy: a randomized, double-blind, placebo-controlled multicenter trial

BACKGROUND

There are presently no available therapeutic options for patients with peanut allergy.

OBJECTIVE

We sought to investigate the safety, efficacy, and immunologic effects of peanut sublingual immunotherapy (SLIT).

METHODS

After a baseline oral food challenge (OFC) of up to 2 g of peanut powder (approximately 50% protein; median successfully consumed dose [SCD], 46 mg), 40 subjects, aged 12 to 37 years (median, 15 years), were randomized 1:1 across 5 sites to daily peanut or placebo SLIT. A 5-g OFC was performed after 44 weeks, followed by unblinding; placebo-treated subjects then crossed over to higher dose peanut SLIT, followed by a subsequent crossover Week 44 5-g OFC. Week 44 OFCs from both groups were compared with baseline OFCs; subjects successfully consuming 5 g or at least 10-fold more peanut powder than the baseline OFC threshold were considered responders.

RESULTS

After 44 weeks of SLIT, 14 (70%) of 20 subjects receiving peanut SLIT were responders compared with 3 (15%) of 20 subjects receiving placebo (P < .001). In peanut SLIT responders, median SCD increased from 3.5 to 496 mg. After 68 weeks of SLIT, median SCD significantly increased to 996 mg (compared with Week 44, P = .05). The median SCD at the Week 44 Crossover OFC was significantly higher than baseline (603 vs 71 mg, P = .02). Seven (44%) of 16 crossover subjects were responders; median SCD increased from 21 to 496 mg among responders. Of 10,855 peanut doses through the Week 44 OFCs, 63.1% were symptom free; excluding oral-pharyngeal symptoms, 95.2% were symptom free.

CONCLUSIONS

Peanut SLIT safely induced a modest level of desensitization in a majority of subjects compared with placebo. Longer duration of therapy showed statistically significant increases in the SCD.

Peanut oral immunotherapy: is it ready for clinical practice?

The prevalence of peanut allergy in the United States and other Westernized countries has tripled in the past 15 years, now affecting more than 1% of the population. Strict peanut avoidance is the current standard of care. In the past decade, a number of small, largely uncontrolled clinical trials have suggested that oral immunotherapy (OIT) can effectively desensitize most children with peanut allergy. Some in the allergy community now feel that OIT is ready for clinical practice. In this review, the evidence base in the medical literature is examined. Although peanut OIT shows promise, the evidence currently available on its effectiveness, risk benefit, and potential long-term consequences is insufficient to support its use in clinical practice. Appropriately designed, prospective clinical trials are urgently needed to determine whether OIT is a safe, effective form of therapy for food allergy.

Community opinions regarding oral immunotherapy for food allergies

BACKGROUND

Food oral immunotherapy (OIT) is a promising but still investigational new therapy for food allergy.

OBJECTIVE

We sought to investigate beliefs and opinions among OIT participants and nonparticipants to better understand community awareness of this therapy.

METHODS

A 30-question on-line survey was administered to members, website visitors, and social media followers of the Kids with Food Allergy Foundation. Questions inquired about general knowledge and attitudes about OIT, its reported safety and efficacy, complications, insurance coverage, and its Food and Drug Administration (FDA) approval status.

RESULTS

Among 1,274 survey respondents, 15.9% had discussed OIT as a treatment option with their allergy provider. Five percent (n = 64) of respondents reported that their child was currently participating in OIT, including 73.4% (n = 47) in a private practice setting. Participants reported varying degrees of being informed about OIT safety (85%), efficacy (46.4% told unrestricted ingestion), risks (relapse 53.4%, eosinophilic esophagitis 3.5%, oral allergy syndrome 10.7%, and failure 56.9%). Significantly fewer participants than nonparticipants agreed that OIT's present safety, efficacy, risks, and approval status would dissuade participation. Significantly fewer participants agreed that OIT should not be offered outside the research setting without definitive proof of both its safety and efficacy.

CONCLUSION

In this exploratory study, differences in beliefs and opinions existed between OIT participants and nonparticipants. Among participants, there were also significant differences in beliefs among academic versus nonacademic participants. Accurate and complete information about OIT safety, efficacy, risks, and approval status was not universally conveyed.

Advances in immunotherapy for food allergy

Food allergy is a life-threatening allergic disease that is increasing in prevalence with no approved curative therapy. Standard treatment of food allergy is limited to avoidance of the allergen and supportive management of allergic symptoms and anaphylaxis. Current research, however, has been focused on developing therapy that can modify the allergic immune response in both allergen-specific and non-specific methods. This review will provide an overview of these methods including oral immunotherapy, sublingual immunotherapy, epicutaneous immunotherapy, modified food protein vaccines, anti-IgE monoclonal antibody adjuvant therapy, Chinese herbs, and helminth therapy.