A phase II, randomized, double‑blind, parallel‑group, placebo‑controlled oral food challenge trial of Xolair (omalizumab) in peanut allergy

Food allergy: Epidemiology, pathogenesis, diagnosis, and treatment

This review focuses on advances and updates in the epidemiology, pathogenesis, diagnosis, and treatment of food allergy over the past 3 years since our last comprehensive review. On the basis of numerous studies, food allergy likely affects nearly 5% of adults and 8% of children, with growing evidence of an increase in prevalence. Potentially rectifiable risk factors include vitamin D insufficiency, unhealthful dietary fat, obesity, increased hygiene, and the timing of exposure to foods, but genetics and other lifestyle issues play a role as well. Interesting clinical insights into pathogenesis include discoveries regarding gene-environment interactions and an increasing understanding of the role of nonoral sensitizing exposures causing food allergy, such as delayed allergic reactions to carbohydrate moieties in mammalian meats caused by sensitization from homologous substances transferred during tick bites. Component-resolved diagnosis is being rapidly incorporated into clinical use, and sophisticated diagnostic tests that indicate severity and prognosis are on the horizon. Current management relies heavily on avoidance and emergency preparedness, and recent studies, guidelines, and resources provide insight into improving the safety and well-being of patients and their families. Incorporation of extensively heated (heat-denatured) forms of milk and egg into the diets of children who tolerate these foods, rather than strict avoidance, represents a significant shift in clinical approach. Recommendations about the prevention of food allergy and atopic disease through diet have changed radically, with rescinding of many recommendations about extensive and prolonged allergen avoidance. Numerous therapies have reached clinical trials, with some showing promise to dramatically alter treatment. Ongoing studies will elucidate improved prevention, diagnosis, and treatment.

Food Allergy

Food allergy has established itself as a matter of significant public health importance and relevance. It has had substantial impacts across the world and continues to represent the most common cause of anaphylaxis seen in emergent settings. However, its increasing incidence has yielded a silver lining of increased interest and investment, which has powered major research in the field. Much has been learned about food allergy as a result. Recent work has elicited increased understanding about food allergy prevalence, mechanisms, and risk factors. In turn, this has allowed for application of this understanding to potential treatments. Current practice of food allergy treatment through restricted exposure may ultimately be replaced with novel therapies including, perhaps ironically, introduction of the allergenic foods in question. This review presents broad highlights of the rapidly increasing understanding into food allergy mechanisms and experimental therapies.

A patient with steroids and antihistaminic drug allergy and newly occurred chronic urticaria angioedema: what about omalizumab?

In this case report, successful use of omalizumab in the treatment of chronic urticarial and angioedema in a 24-year-old female patient with an allergic reaction history to almost every drug including steroids and antihistamines was presented. She also had allergy against a large number of foods, which were confirmed by oral provocation, specific Immunoglobulin E and allergy skin test.

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.

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.

Position document: IgE-mediated allergy to egg protein

Egg is the food that most often causes allergy in young Spanish children, with an incidence of 2.4-2.6% in the first 2 years of life. The prevalence of sensitisation and allergy to egg is greater in children with allergy to cow's milk and in those suffering atopic dermatitis. The protein component from egg white is the cause of the allergic response in child. The major allergens in egg white are ovomucoid and ovalbumin. Most of the allergic reactions affect the skin, followed by gastrointestinal and respiratory systems. Egg allergy is one of the most common causes of severe anaphylaxis. The diagnosis of egg allergy is based on the existence of a suggestive clinical history, a positive allergy study and the subsequent application of controlled exposure testing, which represents the gold standard for confirming the diagnosis. The treatment of egg allergy is based on the avoidance of egg protein intake. A subgroup of egg-allergic patients are tolerant to cooked egg. In these cases, only uncooked egg must necessarily be avoided. Maintaining a diet with strict egg avoidance is difficult, and transgressions are relatively common. The patient, family, and school environment should receive education and training in the avoidance of egg and in the management of possible allergic reactions. With an avoidance diet, up to 15-20% of children will remain allergic and the severity of the reactions will increase over the years. In these more severe cases of egg-allergy, it becomes more difficult to adhere to the avoidance diet over the years, with a significant decrease in patient quality of life. Oral tolerance induction can be regarded as a therapeutic option for IgE-mediated egg allergy. The anti-IgE, omalizumab, might become another genuine therapeutic option for food allergy, not only to prevent allergic reactions after a contact with egg, but also as a complementary treatment to oral tolerance induction for egg allergy, with the purpose of reducing adverse reactions. The administration of influenza vaccine to children with egg allergy is safe in children that do not manifest severe reactions after egg intake, and in children who tolerate cooked egg. The triple viral vaccine (MMR) can be given to egg-allergic children in their usual vaccination centre, with no added risk. Different medicinal products can be formulated with egg proteins, and therefore should be avoided in children with egg 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.

Thymic stromal lymphopoietin-elicited basophil responses promote eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a food allergy-associated inflammatory disease characterized by esophageal eosinophilia. Current management strategies for EoE are nonspecific, and thus there is a need to identify specific immunological pathways that could be targeted to treat this disease. EoE is associated with polymorphisms in the gene that encodes thymic stromal lymphopoietin (TSLP), a cytokine that promotes allergic inflammation, but how TSLP might contribute to EoE disease pathogenesis has been unclear. Here, we describe a new mouse model of EoE-like disease that developed independently of IgE, but was dependent on TSLP and basophils, as targeting TSLP or basophils during the sensitization phase limited disease. Notably, therapeutic TSLP neutralization or basophil depletion also ameliorated established EoE-like disease. In human subjects with EoE, we observed elevated TSLP expression and exaggerated basophil responses in esophageal biopsies, and a gain-of-function TSLP polymorphism was associated with increased basophil responses in patients with EoE. Together, these data suggest that the TSLP-basophil axis contributes to the pathogenesis of EoE and could be therapeutically targeted to treat this disease.

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.

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.

An unfolded variant of the major peanut allergen Ara h 2 with decreased anaphylactic potential

BACKGROUND

Peanut allergy causes severe type 1 hypersensitivity reactions and conventional immunotherapy against peanut allergy is associated with a high risk of anaphylaxis.

OBJECTIVE

Our current study reports proof of concept experiments on the safety of a stably denatured variant of the major peanut allergen Ara h 2 for immunotherapy. We determined the impact of structure loss of Ara h 2 on its IgE binding and basophil degranulation capacity, T cell reactivity as well as anaphylactic potential.

METHODS

The secondary structure of untreated and reduced/alkylated Ara h 2 variants was determined by circular dichroism spectroscopy. We addressed human patient IgE binding to Ara h 2 by ELISA and Western blot experiments. RBL-SX38 cells were used to test the degranulation induced by untreated and reduced/alkylated Ara h 2. We assessed the anaphylactic potential of Ara h 2 variants by challenge of sensitized BALB/c mice. T cell reactivity was investigated using human Ara h 2-specific T cell lines and splenocytes isolated from sensitized mice.

RESULTS

Reduction/alkylation of Ara h 2 caused a decrease in IgE binding capacity, basophil degranulation and anaphylactic potential in vivo. However, the human T cell response to reduced/alkylated and untreated Ara h 2 was comparable. Mouse splenocytes showed higher metabolic activity upon stimulation with reduced/alkylated Ara h 2 and released similar IL-4, IL-13 and IFNγ levels upon treatment with either Ara h 2 variant.

CONCLUSIONS AND CLINICAL RELEVANCE

Reduced/alkylated Ara h 2 might be a safer alternative than native Ara h 2 for immunotherapeutic treatment of peanut allergic patients.

Molecular diagnosis of peanut allergy

Peanut allergy prevalence has increased in developed countries over the last few decades in the frame of the allergy epidemics, currently affecting 1-2% of children. While less frequent in developing countries, its prevalence is rising as these countries adopt a more westernized lifestyle. There is no curative treatment for peanut allergy at present so patient management relies on peanut avoidance, which requires an accurate diagnosis. Recent progress in peanut allergy diagnosis was made with the introduction of component resolved diagnosis that allows the assessment of IgE specific to individual peanut allergens. Component-resolved diagnosis needs to be interpreted in the context of clinical data but overall increases the diagnostic accuracy, as described in the typical cases that we present. Novel diagnostic tools have been proposed recently, such as the basophil activation test, mRNA expression and resonance magnetic evaluation of biomarkers.

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.

The pathologic and clinical intersection of atopic and autoimmune disease

Hypersensitivity reactions of the immune system have been broadly categorized into the atopic and autoimmune depending on whether the antigen triggering the reaction is endogenous (or self) or exogenous, the types of cellular and humoral components involved, and the clinical symptoms. Research into the pathophysiology of the resultant disease states has focused on a dichotomy between Th1 and Th2 T helper lymphocytes thought to govern autoimmune and atopic disease, respectively. Recent discoveries, however, have served to dispute this paradigm and have provided additional insight into the roles of Th17 cells, B-lymphocytes and T regulatory cells as well as the considerable communication and commonalities between the complex signaling pathways. Furthermore, clinical studies have served to challenge the idea that the presence of atopy and autoimmunity are mutually exclusive states. Finally, application of recent approaches to treatment-biologic targeted therapy in autoimmunity and induction of immune tolerance in atopic disease--to both disease states have shown mixed but promising results.

Anti-IgE--emerging opportunities for Omalizumab

INTRODUCTION

Omalizumab is a recombinant DNA-derived humanized IgG1 monoclonal antibody that selectively binds to free and membrane-bound immunoglobulin E (IgE) antibodies. Omalizumab has been licensed for use in severe allergic asthma. A search on the website clinicaltrials.gov reveals there are currently 109 clinical trials with Omalizumab of which 46 are for conditions other than asthma.

AREAS COVERED

In addition to asthma, Omalizumab has been investigated in various other conditions including perennial and seasonal allergic rhinitis (AR), peanut allergy, latex allergy, atopic dermatitis, chronic urticaria (CU), idiopathic anaphylaxis, mastocytosis, eosinophilic gastroenteritis and nasal polyposis. This review aims to look at the various randomised and non-randomised clinical trials, case series and case reports for the role of Omalizumab in conditions other than asthma. Numerous clinical trials have shown a positive light on the role of Omalizumab in conditions other than asthma.

EXPERT OPINION

We feel that the future of Omalizumab would include a more diverse range of clinical conditions, and future trials should not only look into the clinical usefulness but also the economic impact of using this interesting molecule.

Therapeutics in food allergy: the current state of the art

Food allergy is an increasing public health dilemma in Westernized countries, yet no viable treatments are currently available for those who are afflicted. The only options available for patients with food allergies are prevention of reactions by strict avoidance of the offending food(s) and symptomatic treatment of any adverse effects from accidental exposures. Approaches are being pursued to develop treatments, and allergen-specific therapies such as oral immunotherapy, sublingual immunotherapy, and epicutaneous immunotherapy with different foods have shown promise. Other modalities are also being investigated, potentially leading to the discovery of novel therapeutic options.

Vaccines and immunomodulatory therapies for food allergy

The apparent increase in food allergy prevalence has led to a surge in the amount of clinical and basic science research dedicated to the field. At the current time, allergen avoidance remains the cornerstone of treatment; however, recent clinical trials investigating various forms of immunotherapy have opened doors to the possible future application of an active treatment strategy in everyday practice. In addition, improvements in molecular biology have allowed researchers to purify, clone, and modify allergens, thus laying the groundwork for research on vaccines using modified proteins of decreased allergenicity. Finally, various allergen-nonspecific immunomodulatory therapies are also being investigated as a means to alter the immune response to food allergens. With these emerging therapeutic strategies, it is hoped that practitioners will have options in caring for their food-allergic patients in the near future.

Treatments for food allergy: how close are we?

Food allergy continues to be a challenging health problem, with prevalence continuing to increase and anaphylaxis still an unpredictable possibility. While improvements in diagnosis are more accurately identifying affected individuals, treatment options remain limited. The cornerstone of treatment relies on strict avoidance of the offending allergens and education regarding management of allergic reactions. Despite vigilance in avoidance, accidental ingestions and reactions continue to occur. With recent advances in the understanding of humoral and cellular immune responses in food allergy and mechanisms of tolerance, several therapeutic strategies for food allergies are currently being investigated with the hopes of providing a cure or long-term remission from food allergy.

Oral immunotherapy for food allergy: towards a new horizon

Food allergy has increased dramatically in prevalence over the past decade in westernized countries, and is now a major public health problem. Unfortunately for patients with food allergy, there is no effective therapy beyond food allergen avoidance, and rapid medical treatment for accidental exposures. Recently, oral immunotherapy (OIT) has been investigated as a treatment for this problem. In this review, we will discuss the progress in developing OIT for food allergy, including a novel approach utilizing Xolair (anti-IgE monoclonal antibody, omalizumab) in combination with OIT. This combination may enhance both the safety and efficacy of oral immunotherapy, and could lead to a widely available and safe therapy for food allergy.

Kinetics of mast cell, basophil, and oral food challenge responses in omalizumab-treated adults with peanut allergy

BACKGROUND

Monoclonal antibodies directed at IgE demonstrate clinical efficacy in subjects with peanut allergy, but previous studies have not addressed the kinetics of the clinical response or the role of mast cells and basophils in the food-induced allergic response.

OBJECTIVE

We sought to determine the kinetics of the clinical response to omalizumab and whether clinical improvement is associated with either mast cell or basophil suppression.

METHODS

Subjects with peanut allergy were treated with omalizumab for 6 months and assessed for clinical and cellular responses. At baseline, subjects had a double-blind, placebo-controlled oral food challenge (OFC), skin prick test titration (SPTT), and basophil histamine release (BHR) to peanut. BHR was repeated at week 2 and then weekly until it decreased to less than 20% of baseline values. The OFCs and SPTTs were repeated after the BHR reduction (or at week 8 if BHR did not decrease) and again at 6 months.

RESULTS

Fourteen subjects enrolled in the study. At the second food challenge, there was a significant increase in the threshold dose of peanut inducing allergic symptoms (80 to 6500 mg, P < .01). Peanut-induced BHR was either completely suppressed (n = 5) or 10-fold more allergen was required to induce maximal BHR (n = 9), and SPTT responses were not significantly changed from baseline. After 6 months of omalizumab, further changes in the OFC threshold dose or BHR were not observed, but a significant suppression in SPTTs was identified.

CONCLUSIONS

The clinical response to omalizumab occurs early in treatment when the basophil, but not the mast cell, is suppressed, supporting a role for the basophil in acute food reactions.

Revealing the molecular mechanism of gastric cancer marker annexin A4 in cancer cell proliferation using exon arrays

Gastric cancer is a malignant disease that arises from the gastric epithelium. A potential biomarker for gastric cancer is the protein annexin A4 (ANXA4), an intracellular Ca²⁺ sensor. ANXA4 is primarily found in epithelial cells, and is known to be involved in various biological processes, including apoptosis, cell cycling and anticoagulation. In respect to cancer, ANXA4-overexpression has been observed in cancers of various origins, including gastric tumors associated with Helicobacter pylori infection. H. pylori induces ANXA4 expression and intracellular [Ca²⁺]_i elevation, and is an important risk factor for carcinogenesis that results in gastric cancer. Despite this correlation, the role of ANXA4 in the progression of gastric tumors remains unclear. In this study, we have investigated whether ANXA4 can mediate the rate of cell growth and whether ANXA4 downstream signals are involved in tumorigenesis. After observing the rate of cell growth in real-time, we determined that ANXA4 promotes cell proliferation. The transcription gene profile of ANXA4-overexpressing cells was measured and analyzed by human exon arrays. From this transcriptional gene data, we show that overexpression of ANXA4 regulates genes that are known to be related to cancer, for example the activation of hyaluronan mediated motility receptor (RHAMM), AKT, and cyclin-dependent kinase 1 (CDK1) as well as the suppression of p21. The regulation of these genes further induces cancer cell proliferation. We also found Ca²⁺ could regulate the transmission of downstream signals by ANXA4. We suggest that ANXA4 triggers a signaling cascade, leading to increased epithelial cell proliferation, ultimately promoting carcinogenesis. These results might therefore provide a new insight for gastric cancer therapy, specifically through the modification of ANXA4 activity.

Nonallergen-specific treatments for food allergy

PURPOSE OF REVIEW

This review summarizes recent reports on nonallergen-specific therapies for food allergy. These therapies are especially appealing for food allergy because unlike allergen-specific immunotherapy, they would allow the treatment of multiple food allergies in a single patient with one therapy.

RECENT FINDINGS

Chinese herbal therapy, anti-IgE, probiotics, engineered lactic acid bacteria, and helminth therapy are all examples of allergen nonspecific therapies that have been investigated in recent years. Although some have only been studied in animal models of food allergy, some are undergoing rigorous, human clinical trials.

SUMMARY

Increasing amounts of research are examining the efficacy and safety of nonallergen-specific therapies for food allergy. There is hope that clinicians will have effective treatments either as an alternative or as an adjunct to immunotherapy.

Future therapies for food allergy

Food allergy affects 3.9% of US children and is increasing in prevalence. The current standard of care involves avoidance of the triggering food and treatment for accidental ingestions. While there is no current curative treatment, there are a number of therapeutic strategies under investigation. Allergen specific therapies include oral and sublingual immunotherapy with native food protein as well as recombinant food proteins. Allergen non-specific therapies include a Chinese herbal formula (FAHF-2) and the use of anti-IgE monoclonal antibody therapy. Although none of these treatments are ready for clinical use, these therapeutic strategies present promising options for the future of food allergy.

Pepsinized cashew proteins are hypoallergenic and immunogenic and provide effective immunotherapy in mice with cashew allergy

BACKGROUND

IgE-mediated allergic reactions to cashews and other nuts can trigger life-threatening anaphylaxis. Proactive therapies to decrease reaction severity do not exist.

OBJECTIVES

We aimed to determine the efficacy of pepsin-digested cashew proteins used as immunotherapy in a murine model of cashew allergy.

METHODS

Mice were sensitized to cashew and then underwent challenges with digested or native cashew allergens to assess the allergenicity of the protein preparations. Using native or pepsinized cashew proteins, mice underwent oral or intraperitoneal sensitization protocols to determine the immunogenic properties of the protein preparations. Finally, cashew-sensitized mice underwent an immunotherapy protocol with native or pepsinized cashew proteins and subsequent provocation challenges.

RESULTS

Pepsinized cashew proteins elicited weaker allergic reactions than native cashew proteins but importantly retained the ability to stimulate cellular proliferation and cytokine production. Mice sensitized with pepsinized proteins reacted on challenge with native allergens, demonstrating that pepsinized allergens retain immunogenicity in vivo. Immunotherapy with pepsinized cashew allergens significantly decreased allergic symptoms and body temperature decrease relative to placebo after challenge with native and pepsinized proteins. Immunologic changes were comparable after immunotherapy with native or pepsinized allergens: T(H)2-type cytokine secretion from splenocytes was decreased, whereas specific IgG(1) and IgG(2a) levels were increased.

CONCLUSIONS

Pepsinized cashew proteins are effective in treating cashew allergy in mice and appear to work through the same mechanisms as native protein immunotherapy.

Advances in allergic skin disease, anaphylaxis, and hypersensitivity reactions to foods, drugs, and insects in 2011

This review highlights some of the research advances in anaphylaxis; hypersensitivity reactions to foods, drugs, and insects; and allergic skin diseases that were reported in the Journal in 2011. Food allergy appears to be increasing in prevalence and carries a strong economic burden. Risk factors can include dietary ones, such as deficiency of vitamin D and timing of complementary foods, and genetic factors, such as filaggrin loss-of-function mutations. Novel mechanisms underlying food allergy include the role of invariant natural killer T cells and influences of dietary components, such as isoflavones. Among numerous preclinical and clinical treatment studies, promising observations include the efficacy of sublingual and oral immunotherapy, a Chinese herbal remedy showing promising in vitro results, the potential immunotherapeutic effects of having children ingest foods with baked-in milk if they tolerate it, and the use of anti-IgE with or without concomitant immunotherapy. Studies of allergic skin diseases, anaphylaxis, and hypersensitivity to drugs and insect venom are elucidating cellular mechanisms, improved diagnostics, and potential targets for future treatment. The role of skin barrier abnormalities, as well as the modulatory effects of the innate and adaptive immune responses, are major areas of investigation.

The future of food allergy therapeutics

Food allergy is increasing in prevalence in westernized countries, leading to significant morbidity including nutritional deficiencies and growth delay as well as psychosocial burdens and the potential for fatal anaphylaxis. There is currently no effective form of therapy, and the mainstay of treatment remains strict avoidance. However, there are a number of promising therapeutic strategies currently being investigated for the treatment of food allergies. Allergen-specific approaches, such as various forms of immunotherapy, have been a major focus of investigation and appear to be promising methods of desensitization. More recently, the addition of anti-IgE monoclonal antibodies (mAbs) to immunotherapy regimens has been studied. Early work with antigen-fixed leukocytes in a murine model has shown promise in inducing tolerance, as have vaccines containing modified recombinant food proteins coadministered with heat-killed Escherichia coli. Nonspecific approaches include a Chinese herbal formulation, anti-IgE mAbs, and Trichuris suis ova therapy. The array of treatment modalities currently being investigated increases the likelihood of finding one or more effective therapies for the treatment of food allergy.

Food allergy: mechanisms and therapeutics

The immunologic mechanisms responsible for the development of allergic sensitization rather than tolerance to foods are not well understood, although there have been a number of recent advances in our understanding of why some foods are inherently allergenic. In addition, the involvement of alternative routes of exposure that are not inherently tolerogenic may play a role in sensitization to foods. Although there are no currently accepted therapeutic approaches to food allergy, there are a number of approaches to treatment in preclinical or clinical trials. Here, we review selected findings published since 2009 that advance our understanding of mechanisms and new therapeutics for IgE-mediated food allergy.

Food allergies and asthma

PURPOSE OF REVIEW

To consider the possible links between food allergy and asthma.

RECENT FINDINGS

Food allergy and asthma coexist in many children, and recent studies demonstrate that having these comorbid conditions increases the risk for morbidity. Children with food allergies and asthma are more likely to have near-fatal or fatal allergic reactions to food and more likely to have severe asthma.

SUMMARY

Although a causal link has not been determined, increased awareness of the heightened risks of having both of these common childhood conditions and good patient/parent education and management of both conditions can lead to improved outcomes.

Allergic rhinitis and asthma: celebrating 100 years of immunotherapy

Since Noon first described allergen immunotherapy a century ago the basic premise of subcutaneous injections (SCIT) of relevant aeroallergens to induce clinical tolerance has remained true [1]. Indeed, allergen immunotherapy did not change dramatically over the first 75 years, but over the past 25 years there have been a number of important advancements leading to newer approaches and novel formulations. Here we review the top 50 articles published in the past 2 years on allergens, environmental control, and immunotherapy for asthma and allergic rhinitis and the use of immunomodulators in allergic disease.

Future therapies for food allergies

Food allergy is an increasingly prevalent problem in westernized countries, and there is an unmet medical need for an effective form of therapy. A number of therapeutic strategies are under investigation targeting foods that most frequently provoke severe IgE-mediated anaphylactic reactions (peanut, tree nuts, and shellfish) or are most common in children, such as cow's milk and hen's egg. Approaches being pursued are both food allergen specific and nonspecific. Allergen-specific approaches include oral, sublingual, and epicutaneous immunotherapy (desensitization) with native food allergens and mutated recombinant proteins, which have decreased IgE-binding activity, coadministered within heat-killed Escherichia coli to generate maximum immune response. Diets containing extensively heated (baked) milk and egg represent an alternative approach to food oral immunotherapy and are already changing the paradigm of strict dietary avoidance for patients with food allergy. Nonspecific approaches include monoclonal anti-IgE antibodies, which might increase the threshold dose for food allergen in patients with food allergy, and a Chinese herbal formulation, which prevented peanut-induced anaphylaxis in a murine model and is currently being investigated in clinical trials. The variety of strategies for treating food allergy increases the likelihood of success and gives hope that accomplishing an effective therapy for food allergy is within reach.

Food allergy

Food allergies affect up to 6% of young children and 3%-4% of adults. They encompass a range of disorders that may be IgE and/or non-IgE mediated, including anaphylaxis, pollen food syndrome, food-protein-induced enterocolitis syndrome, food-induced proctocolitis, eosinophilic gastroenteropathies, and atopic dermatitis. Many complex host factors and properties of foods are involved in the development of food allergy. With recent advances in the understanding of how these factors interact, the development of several novel diagnostic and therapeutic strategies is underway and showing promise.

Immunotherapy in food allergy

Food allergies are caused by immune responses to food proteins and represent a breakdown of oral tolerance. They can range from mild pruritus to life-threatening anaphylaxis. The only current consensus for treatment is food avoidance, which is fraught with compliance issues. For this reason, there has been recent interest in immunotherapy, which may induce desensitization and possibly even tolerance. Through these effects, immunotherapy may decrease the potential for adverse serious reactions with accidental ingestions while potentially leading to an overall health benefit. In this review, we discuss the mechanisms of food allergy and give an overview of the various immunotherapeutic options and current supporting evidence, as well as look towards the future of potential novel therapeutic modalities.

Food allergy: recent advances in pathophysiology and treatment

Food allergies are adverse immune reactions to food proteins that affect up to 6% of children and 3-4% of adults. A wide range of symptoms can occur depending on whether IgE or non-IgE mediated mechanism are involved. Many factors influence the development of oral tolerance, including route of exposure, genetics, age of the host, and allergen factors. Advances have been made in the understanding of how these factors interact in the pathophysiology of food allergy. Currently, the mainstay of treatment for food allergies is avoidance and ready access to emergency medications. However, with the improved understanding of tolerance and advances in characterization of food allergens, several therapeutic strategies have been developed and are currently being investigated as potential treatments and/or cures for food allergy.

Towards a cure for food allergy

Over the past two decades, food allergies have become both more prevalent and long lasting. This burgeoning problem has not been met with any therapeutic options to date, and patients must attempt to avoid known allergenic foods and treat any allergic reactions with 'as-needed' medications. There are a number of promising emerging therapeutic modalities for food allergy, including allergen-specific and allergen non-specific immunotherapeutic approaches. Although the allergen-specific approaches have some distinct differences, they all attempt to induce tolerance by exposing the patient to an allergen via the mucosal route (oral tolerance induction). Allergen non-specific approaches include biologics to suppress free total IgE levels (e.g. anti-IgE antibody) or to induce more general immune suppression (Chinese herbal medication).