Home-based oral immunotherapy (OIT) with an intermittent loading protocol in children unlikely to outgrow egg allergy

The Combination of Binding Avidity of Ovomucoid-Specific IgE Antibody and Specific IgG4 Antibody Can Predict Positive Outcomes of Oral Food Challenges during Stepwise Slow Oral Immunotherapy in Children with Hen's Egg Allergy

To increase the prediction accuracy of positive oral food challenge (OFC) outcomes during stepwise slow oral immunotherapy (SS-OIT) in children with a hen's egg (HE) allergy, we evaluated the predictive value of the combination of antigen-specific IgE (sIgE) with antigen binding avidity and sIgG4 values. Sixty-three children with HE allergy undergoing SS-OIT were subjected to repeated OFCs with HE. We measured the ovomucoid (OVM)-sIgE by ImmunoCAP or densely carboxylated protein (DCP) microarray, sIgG4 by DCP microarray, and the binding avidity of OVM-sIgE defined as the level of 1/IC₅₀ (nM) measured by competitive binding inhibition assays. The OFC was positive in 37 (59%) patients undergoing SS-OIT. Significant differences in DCP-OVM-sIgE, CAP-OVM-sIgE, I/IC₅₀, DCP-OVM-sIgG4, the multiplication products of DCP-OVM-sIgE, and the binding avidity of DCP-OVM-sIgE (DCP-OVM-sIgE/IC₅₀) and DCP-OVM-sIgE/sIgG4 were compared between the negative and positive groups (p < 0.01). Among them, the variable with the greatest area under the receiver operating characteristic curve was DCP-OVM-sIgE/IC₅₀ (0.84), followed by DCP-OVM-sIgE/sIgG4 (0.81). DCP-OVM-sIgE/IC₅₀ and DCP-OVM-sIgE/sIgG4 are potentially useful markers for the prediction of positive OFCs during HE-SS-OIT and may allow proper evaluation of the current allergic status in the healing process during HE-SS-OIT.

Home-based, slow up-dosing oral immunotherapy for hen's egg allergy in an adult patient

Standard therapy for food allergies involves avoiding causative foods until a patient has outgrown their allergies. Oral immunotherapy (OIT) is an optional treatment for children unlikely to outgrow their food allergy. However, information about OIT in adult patients with food allergies is very limited. We present a case of severe hen's egg allergy (HEA) in an adult who tried home-based, slow up-dosing OIT, reported to have been tolerable and effective in children. A 20-year-old woman with HEA experienced repeated anaphylaxis since childhood when she consumed a small quantity of hen's egg, so she completely avoided hen's eggs. She underwent inpatient oral food challenge (OFC) with 10-g boiled egg yolk and presented lip swelling and abdominal pain. OFC with 1-g boiled egg yolk the following day induced no adverse reaction. OIT was initiated using a home-based, slow up-dosing protocol. She consumed 1 g of boiled egg yolk at home every day, increasing this by 5%–10% every 2 weeks. She started 0.5-g boiled egg white after reaching a whole egg yolk. If adverse reactions occurred, the daily dose was decreased. After 59 months, she was able to eat an entire boiled egg. Anaphylaxis occurred 3 times during OIT due to accidental consumptions of egg products or insufficient heating of egg. Home-based, slow up-dosing OIT might be applicable for adults with severe HEA. It should be performed with appropriate equipment and education for patients, in case of emergency.

Allergen immunotherapy for food allergy from the Asian perspective: key challenges and opportunities

Introduction: Prevalence of food allergy is rising in different regions of the world. Asia has not been spared from this epidemic, but epidemiological data have revealed a different pattern of food allergens in this continent. Allergen-specific immunotherapy (AIT) for food allergy, which has been revolutionary as the main focus of research in recent years, needs to be adapted for the different populations in Asia. Areas covered: Recent evidence shows increasing popularity and superiority of AIT over strict food avoidance as the cornerstone of food allergy management. Asia is a distinctive continent with specific food allergy triggers, in particular, seafood, and wheat. Peanut, on the contrary, is not a common food allergen in most parts of Asia. The common Asian food allergens, as well as the rapidly developing food-specific AIT in this region will be covered in this article. Expert commentary: Evidence on oral immunotherapy for wheat allergy and preclinical data on shellfish AIT are promising. Further work should be done on resolving cross-sensitization between environmental allergens with wheat and shellfish allergens, and a modified AIT approach to enhance the safety and effectiveness of food-specific immunotherapy.

Clinical and immunological profile of children aged 5-9 years with persistent egg allergy before oral immunotherapy with egg. A multicenter, randomized controlled trial of the Spanish Society of Pediatric Allergy, Asthma and Clinical Immunology (SEICAP)

BACKGROUND

In children with egg protein allergy (EA), the probability of overcoming the allergy decreases with age, and the possibility of suffering severe adverse reactions as a consequence of dietetic transgressions results in worsened quality of life. One treatment option in such cases is oral immunotherapy (OIT) with foods.

METHODS

We present a cohort of children with EA scheduled for OIT with pasteurized raw egg white, describing their clinical and allergic characteristics before the start of OIT.

RESULTS

The median age was six years, and 93% of the patients also suffered other allergies (58% asthma and 38.6% allergy to more than two food groups). In the last year, 14.8% had suffered a severe reaction due to dietetic transgression with egg. The median IgE specific of egg white titer was 38.5kU/l. A double-blind placebo-controlled food challenge with cooked egg white was performed, and if the test proved positive, it was repeated with pasteurized raw egg white. The mean symptoms-provoking dose was 1.26g and 0.55g for cooked egg white and raw egg white, respectively. An IgE specific of ovomucoid titer of <2.045kU/l differentiated those patients that tolerated cooked egg white.

CONCLUSIONS

OIT with egg is regarded as an option in patients with persistent egg allergy. In the previous challenge test, an IgE specific of ovomucoid titer of <2.045kU/l differentiates those patients that tolerate cooked egg white.

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.

Oral immunotherapy for food allergy: A Spanish guideline. Egg and milk immunotherapy Spanish guide (ITEMS GUIDE). Part 2: Maintenance phase of cow milk (CM) and egg oral immunotherapy (OIT), special treatment dosing schedules. Models of dosing schedules of OIT with CM and EGG

INTRODUCTION

Cow's milk and egg are the most frequent causes of food allergy in the first years of life. Treatments such as oral immunotherapy (OIT) have been investigated as an alternative to avoidance diets. No clinical practice guides on the management of OIT with milk and egg are currently available.

OBJECTIVES

To develop a clinical guide on OIT based on the available scientific evidence and the opinions of experts.

METHODS

A review was made of studies published in the period between 1984 and June 2016, Doctoral Theses published in Spain, and summaries of communications at congresses (SEAIC, SEICAP, EAACI, AAAAI), with evaluation of the opinion consensus established by a group of experts pertaining to the scientific societies SEICAP and SEAIC.

RESULTS

Recommendations have been established regarding the indications, requirements and practical aspects of the different phases of OIT, as well as special protocols for patients at high risk of suffering adverse reactions.

CONCLUSIONS

A clinical practice guide is presented for the management of OIT with milk and egg, based on the opinion consensus of Spanish experts.

Oral immunotherapy for food allergy: A Spanish guideline. Immunotherapy egg and milk Spanish guide (items guide). Part I: Cow milk and egg oral immunotherapy: Introduction, methodology, rationale, current state, indications contraindications and oral immunotherapy build-up phase

INTRODUCTION

Cow's milk and egg are the most frequent causes of food allergy in the first years of life. Treatments such as oral immunotherapy (OIT) have been investigated as an alternative to avoidance diets. No clinical practice guides on the management of OIT with milk and egg are currently available.

OBJECTIVES

To develop a clinical guide on OIT based on the available scientific evidence and the opinions of experts.

METHODS

A review was made of studies published in the period between 1984 and June 2016, Doctoral Theses published in Spain, and summaries of communications at congresses (SEAIC, SEICAP, EAACI, AAAAI), with evaluation of the opinion consensus established by a group of experts pertaining to the scientific societies SEICAP and SEAIC.

RESULTS

Recommendations have been established regarding the indications, requirements and practical aspects of the different phases of OIT, as well as special protocols for patients at high risk of suffering adverse reactions.

CONCLUSIONS

A clinical practice guide is presented for the management of OIT with milk and egg, based on the opinion consensus of Spanish experts.

Active treatment for food allergy

Food allergy has grown in rapidly in prevalence, currently affecting 5% of adults and 8% of children. Management strategy is currently limited to 1) food avoidance and 2) carrying and using rescue intramuscular epinephrine/adrenaline and oral antihistamines in the case of accidental ingestion; there is no FDA approved treatment. Recently, oral, sublingual and epicutaneous immunotherapy have been developed as active treatment of food allergy, though none have completed phase 3 study. Efficacy and safety studies of immunotherapy have been variable, though there is clearly signal that immunotherapy will be a viable option to desensitize patients. The use of bacterial adjuvants, anti-IgE monoclonal antibodies, and Chinese herbal formulations either alone or in addition to immunotherapy may hold promise as future options for active treatment. Active prevention of food allergy through early introduction of potentially offending foods in high-risk infants will be an important means to slow the rising incidence of sensitization.

Rush Oral Immunotherapy Does Not Reduce Allergic Response in Mice with Mild Allergy to Egg White Ovomucoid

Oral immunotherapy (OIT) is a promising therapeutic approach for treating food allergy. Past studies have shown that OIT reduces allergic response only in severe allergy model mice. We worked to establish mild allergy model mice, and investigated whether 'rush' OIT for 10 d improved the allergic response and biomarkers in these mice. Balb/c mice were sensitized to ovomucoid (OM) in alum. The rush OIT was done for 10 d. Oral OM challenge was used to determine the impact of OIT on the allergic response. We measured allergic biomarkers, such as vascular permeability in the skin, plasma levels of total IgE, OM-specific IgE, IgG1 and IgG2a and cytokines in splenocyte culture supernatant. OIT for 10 d did not improve allergy symptoms and increased vascular permeability. Total IgE in the plasma of OIT-treated mice was significantly higher than in that of non-treated mice. OM-specific IgG1 and IgG2a plasma levels were not significantly different between OIT-treated and non-treated mice. Among the cytokine secretion of splenocyte from OIT-treated mice, IFN-γ and IL-10 were significantly lower than in non-treated mice, and IL-4 and IL-5 were significantly higher. Total TGF-β in the OIT-treated group was not detected. The IFN-γ/IL-4 ratio of the OIT-treated group was about 1/8 that of the non-treated group. OIT for 10 d was not effective and some biomarkers showed negative responses in the mild allergy model mice. We suggest OIT should be used very carefully as this treatment carries a risk of worsening allergy symptoms for mice with mild allergy.

Pharmacologic options for the treatment and management of food allergy

Food allergy affects approximately 5% of adults and 8% of children in developed countries, and there is currently no cure. Current pharmacologic management is limited to using intramuscular epinephrine or oral antihistamines in response to food allergen exposure. Recent trials have examined the efficacy and safety of subcutaneous, oral, sublingual, and epicutaneous immunotherapy, with varying levels of efficacy and safety demonstrated. Bacterial adjuvants, use of anti-IgE monoclonal antibodies, and Chinese herbal formulations represent exciting potential for development of future pharmacotherapeutic agents. Ultimately, immunotherapy may be a viable option for patients with food allergy, although efficacy and safety are likely to be less than ideal.

Clinical efficacy and immunological changes subjacent to egg oral immunotherapy

BACKGROUND

Evidence of the efficacy of food oral immunotherapy (OIT) is not robust enough to change clinical practice from current standard management. Furthermore, the immunologic changes underlying food desensitization are unknown.

OBJECTIVE

To establish the immunologic basal status and differences between an egg-allergic group of children and a population of nonallergic children and to investigate the safety and efficacy of a specific egg OIT protocol to induce clinical desensitization and the associated immune responses.

METHODS

Children with or without egg allergy were recruited. Allergic subjects underwent an OIT protocol based on weekly doses of egg protein and a maintenance phase. Immune profile and changes in all subjects were investigated by measuring T-helper cells types 1 and 2 (TH1 and TH2) and T-regulatory cytokines and transcription factors and egg-specific IgE and IgG4 levels.

RESULTS

At baseline, a significantly lower production of ovalbumin-specific interleukin (IL)-10 and tumor necrosis factor-α and a trend toward higher IL-5 and IL-13 were found in allergic children. The egg OIT protocol enabled 60% of them to ingest 32 mL of egg white. Significant increases in egg-specific IgG4 levels and IL-10 production, with a trend toward lower IL-5 and IL-13 and higher tumor necrosis factor-α and interferon-γ levels, and significant decreases in egg-specific IgE concentration were observed.

CONCLUSION

Egg-allergic individuals display a bias toward TH2 type cytokine production and decreased TH1 and IL-10 responses compared with nonallergic individuals. The OIT protocol was safe and effective in inducing egg desensitization, leading to a shift in the immune profile of allergic individuals toward a nonallergic phenotype.

Transgenic plants for allergen-specific immunotherapy

Allergen-specific immunotherapy (IT) is an effective treatment for allergic diseases. Although subcutaneous and sublingual ITs are currently used, safer, easier, and more effective IT is under development. Induction of immune tolerance by oral administration of allergen has been proven, though oral IT has not been applied clinically. It is mainly because a large amount of purified allergen is required to induce oral tolerance. To overcome this problem, plants, peculiarly rice, have been investigated as allergen vehicles for oral IT. Rice can store a considerable amount of expressed allergen in its seeds and the accumulated allergen is stable and resistant to gastrointestinal digestion. Therefore, we have developed transgenic rice seeds (Tg rice) in which major epitopes of cedar pollen or house dust mites are expressed. We are establishing Tg rice with demonstrated efficacy in murine models of allergic rhinitis and bronchial asthma by oral administration at practical doses. In addition, the amount, distribution, and allergenicity of the expressed allergen have been improved in our Tg rice. Rice-based oral IT is a promising new concept in IT for the treatment of allergic diseases.