EAACI Guidelines on allergen immunotherapy: IgE-mediated food allergy

Role of biologics in severe food allergy

PURPOSE OF REVIEW

This review examine the dynamic landscape of food allergy treatment within the context of emerging biologics. Our purpose is to comprehensively evaluate the potential benefits, challenges, and transformative impact associated with the utilization of biologics in comparison to conventional therapeutic modalities.

RECENT FINDINGS

This document synthesizes recent scientific investigations to various biologics, such as omalizumab, ligelizumab, dupilumab, and tezepelumab, providing a nuanced understanding of their roles in oral immunotherapy, rapid desensitization, and overall food allergy management. Recent studies and clinical trials highlight the impact of anti-IgE treatment on food allergies, revealing critical findings such as dose-related efficacy, facilitation of rapid desensitization in peanut allergies, and the sustained positive outcomes observed in individuals with multifood allergies.

SUMMARY

The use of biologics presents a groundbreaking approach in the treatment of food allergies. The multifaceted action of these agents, along with their potential to overcome the challenges associated with traditional therapies, marks a significant advancement. Despite the persisting challenges of economic constraints and the need for further safety studies, biologics offer a promising avenue for improving the quality of life for individuals with food allergies. Ongoing research and collaborative efforts are imperative to fully realize the transformative potential inherent in these emerging therapeutic frontiers.

Perspectives in the validation of DEFASE: a paradigm shift in food allergy management

PURPOSE OF REVIEW

To explore the groundbreaking international consensus on the DEFASE (DEfinition of Food Allergy Severity) project as a revolutionary grading system for IgE-mediated food allergy severity. Against the backdrop of the growing public health challenge posed by food allergy, this article delves into the importance of validating and implementing DEFASE in real-world clinical settings.

RECENT FINDINGS

With new therapeutic options available for food allergy, including biologics alongside immunotherapy, it is urgent to properly support clinical decision-making in the management of the disease. The DEFASE score is the first international consensus-based grading system of severity associated with food allergy as a whole disease embracing multidisciplinary perspectives from different stakeholders involved. In its current version, this comprehensive scoring system has been developed to be used in research settings.

SUMMARY

The review emphasizes the potential impact of DEFASE on patient outcomes, healthcare management, and resource allocation, underscoring its significance for the allergy scientific community. Future research should focus on internal and external validation of the scoring system, targeting these models to various food allergenic sources, populations, and settings.

How to hit the allergy target: A critical appraisal of intralymphatic immunotherapy with practical recommendations on ultrasound-guided injections

BACKGROUND

Intralymphatic immunotherapy (ILIT) represents a promising novel approach treating allergic diseases. However, no standardized procedures or recommendations have been established or reported, despite the recognized fact that treatment efficacy relies on the ability to inject the allergen intranodally.

OBJECTIVE

We aim to provide a critical appraisal of ILIT as a method of allergen immunotherapy and to deliver practical recommendations for accurate ILIT.

METHODS

One hundred and seventy-three ILIT injections were performed in 28 (47%) women and 32 (53%) men with median age of 29 years (21-59). The injections were ultrasound-guided and recorded for retrospective analysis with respect to injection location, needle visibility, medication release, and patient characteristics.

RESULTS

The results show that the correct positioning of the needle within the lymph node (LN) was most critical. If the whole length of the needle bevel was not inserted into the LN, substance backflush into the interstitium was observed. Selecting a more superficial LN and inserting the needle at a smaller angle towards the LN significantly improved needle visibility in the ultrasound. Longitudinal results showed that continuous practice significantly correlated with improved needle visibility and more accurate ILIT injections.

CONCLUSION

Based on our results and practical experience, we propose several recommendations for LN selection and the correct handling of ultrasound probe and needle. We are confident that ILIT standardization and training will be important as to meet the goals of good safety and efficacy of ILIT.

Challenge-verified thresholds for allergens mandatory for labeling: How little is too much for the most sensitive patient?

BACKGROUND

It is mandatory to label food products with the 14 main allergens in the EU. Reasonable allergen labeling requires knowledge of population-based thresholds derived from food challenges. The aim of this study was to evaluate the threshold-distribution in clinically verified food allergic patients for allergens mandatory for labeling.

METHODS

All positive open oral food challenges and double-blind placebo-controlled food challenges (DBPCFC) performed at the Allergy Center, Odense University Hospital, Denmark (2000-2022) were included. For each included challenge, the cumulative threshold (LOAEL) was obtained and NOAEL estimated. Data were modelled as an interval censored log-normal distribution.

RESULTS

Overall, 38 of all 2612 challenges (1.5%) in 1229 patients (717 male, 986 children) reacted to <5 mg protein. The majority of the most sensitive patients reacted with a Sampson severity score of 2-3. Using interval censored log-normal models only five groups (hens´ egg, fish, peanut, milk, tree-nuts) elicited reactions after ingestion of 0.5 mg protein and in low frequencies of the population. Hen's egg was the most potent allergen, with reactivity to <0.5 mg protein in 0.24% [0.13-0.44%] of egg allergic patients while the estimated fraction of allergic patients reacting to a eliciting dose on 0.5 mg protein for most other allergens were below 0.04%.

CONCLUSION

Our data demonstrates that the majority of food allergic patients as expected tolerating traces of allergenic foods without developing severe allergic symptoms and signs. Hen's egg appears to be the food most likely to elicit reactions in the most sensitive individuals at very low doses.

Cow's Milk Protein Allergy

Cow's milk allergy refers to an immunological reaction to milk protein. It is one of the commonest food protein allergies with an estimated prevalence of 0.5% to 3% at 1 y of life. The disease may be IgE or non-IgE mediated or mixed with a wide range of symptoms often involving multiple organ systems. Gastrointestinal manifestations are common in non-IgE disease and may consist of enteropathy, proctocolitis, colic, reflux-like symptoms, constipation, enterocolitis syndrome and eosinophilic esophagitis. The gold standard for diagnosis remains a double-blind placebo-controlled oral challenge. Specific IgE and skin prick tests may predict severe and persistent disease, and aid in deciding on reintroduction or oral immunotherapy; however, they do not contribute to a definitive diagnosis as they indicate only sensitization. In practice, an elimination diet followed by open challenge under medical supervision is often used for diagnosis except when symptoms are severe such as anaphylaxis. Management consists of the elimination of the allergen with resolution of symptoms between 1-4 wk later depending on the type of allergy. Extensively hydrolyzed and Amino acid formulas are used to substitute milk in infants. Soy-based formulas are often utilized in resource-limited settings. Tolerance to the protein develops over time and periodic reintroduction should be attempted every six months after the initial one year of elimination diet. Oral immunotherapy is a newer treatment technique for IgE-mediated disease. There is no firm evidence on prevention apart from recommending breast feeding in early life along with initiating complementary feeding between 4-6 mo age.

Current state and advances in desensitization for peanut allergy in pediatric age

Peanut allergy affects about 1%-3% of the pediatric population in the world, with an important increase in the last decades. Nowadays, international guidelines recommend the early introduction of peanuts in the infant diet, with poor information about the quantity and the frequency of the intake. Allergen immunotherapy may represent the only therapeutic strategy able to modify the natural history of peanut allergy. In particular, oral immunotherapy showed the most promising results in terms of efficacy, but with significant rates of adverse reactions, mostly gastrointestinal. In 2020, the Food and Drug Administration and the European Medicines Agency approved Palforzia®, an oral drug for patients aged 4-17 years. Several studies are ongoing to improve the tolerability of oral immunotherapy and standardize the desensitization protocols. Sublingual immunotherapy permits to offer much lower doses than oral immunotherapy, but fewer adverse events are shown. Subcutaneous immunotherapy is associated with the greatest systemic adverse effects. Epicutaneous immunotherapy, for which Viaskin® patch was approved, has the highest safety profile. Innovative studies are evaluating the use of biological drugs, such as omalizumab or dupilumab, and probiotics, such as Lactobacillus rhamnosus, in monotherapy or associated with oral immunotherapy. Therapy for peanut allergy is constantly evolving, and new perspectives are ongoing to develop.

Evaluation of clinical outcomes of efficacy in food allergen immunotherapy trials, COFAITH EAACI task force

Food allergy is a global public health problem that until recent years lacked any aetiological treatment supported by academy, industry and regulators. Food immunotherapy (AIT) is an evolving treatment option, supported by clinical practice and industry trial data. Recent AIT meta-analyses have highlighted the difficulty in pooling safety and efficacy data from AIT trials, due to secondary heterogeneity in the study. An EAACI task force (CO-FAITH) initiated by the Paediatric Section was created to focus on AIT efficacy outcomes for milk, egg and peanut allergy rather than in trial results. A systematic search and a narrative review of AIT controlled clinical trials and large case series was conducted. A total of 63 manuscripts met inclusion criteria, corresponding to 23, 21 and 22 studies of milk, egg and peanut AIT, respectively. The most common AIT efficacy outcome was desensitization, mostly defined as tolerating a maintenance phase dose, or reaching a particular dose upon successful exit oral food challenge (OFC). However, a large degree of heterogeneity was identified regarding the dose quantity defining this outcome. Sustained unresponsiveness and patient-reported outcomes (e.g. quality of life) were explored less frequently, and to date have been most rigorously described for peanut AIT versus other allergens. Change in allergen threshold assessed by OFC remains the most common efficacy measure, but OFC methods suffer from heterogeneity and methodological disparity. This review has identified multiple heterogeneous outcomes related to measuring the efficacy of AIT. Efforts to better standardize and harmonize which outcomes, and how to measure them must be carried out to help in the clinical development of safe and efficacious food allergy treatments.

A randomized, double-blind placebo-controlled study on the efficacy of Omalizumab on food allergy threshold in children with severe food allergy

BACKGROUND

Food allergy is common in childhood with some children having a low threshold and being difficult to protect from accidental ingestion of the offending food. Therapies for this potentially life-threatening condition are highly needed. The aim of this study was to evaluate the efficacy of Omalizumab in food-allergic children.

METHODS

This is a single-center, double-blind, placebo-controlled study. Food allergic children with a cumulative threshold ≤443 mg food protein at DBPCFC were randomized to Omalizumab (asthma dose) or placebo (3:1). After 3 months, a second DBPCFC was performed (steps 3, 10, 30, 100, 300, 1000, and 3000 mg food protein), followed by a separate open challenge up to 10,000 and 30,000 mg food protein if negative. Responders were defined as ≥2-step increases in threshold. Non-responders received high-dose Omalizumab. A third DBPCFC was performed after 6 months. Skin testing, blood samples, and the severity of atopic co-morbidity were registered during the study and 3 months after treatment.

RESULTS

In total, 20 children were evaluated at 3 months (14 Omalizumab, 6 placebo). All treated with Omalizumab increased their threshold at least two steps and with a significant difference between the Omalizumab and the placebo group (p = .003), although the intended number of included children was not reached. The threshold before Omalizumab treatment was 13-443 mg food protein while the threshold after 3 months of treatment increased up to 44,000 mg (1143-44,000). In the placebo group, two children improved threshold during the study.

CONCLUSION

An increase in the threshold level during Omalizumab treatment significantly improve patient safety and protected all children against small amount of allergen.

A Review of Shared Decision-Making, Published Protocols, and Post-desensitization Strategies in Oral Immunotherapy (OIT)

PURPOSE OF REVIEW

The aim of this review is to highlight key published oral immunotherapy (OIT) protocols and post-desensitization strategies for the major food allergens and to cover important concepts to consider when evaluating OIT for food-allergic patients. Shared decision-making should help identify patient and family values which will help influence the type of evidence-based protocol and maintenance strategy to use.

RECENT FINDINGS

With food OIT emerging as a treatment option, there is a pressing need for patients, physicians, and other providers to have a nuanced understanding of the management choices available to them. There are now randomized controlled trials (RCT) of OIT for peanut, egg, milk, and wheat, and reports of cohorts of patients who have undergone OIT for tree nuts and sesame clinically. The current published protocols contain significant diversity in terms of starting dose, build-up schedule, maintenance dose, and even the product used for desensitization. Emerging data can help direct the long-term maintenance strategy for patients on OIT. Based on patient and family values elicited through the shared decision-making process, an OIT protocol may be selected that balances the level of desensitization, potential side effects, frequency of clinic visits, and potential to induce sustained unresponsiveness, among other factors. Once maintenance dosing is reached, most patients will need to maintain regular exposure to the food allergen to remain desensitized. The option to transition to commercial food products with equivalent amounts of food protein as the OIT maintenance dose would simplify the dosing process and perhaps improve palatability as well. Less frequent or decreased OIT dosing can provide practical benefits but may affect the level of desensitization and safety for some patients.

Preparing Patients for Oral Immunotherapy (PPOINT): International Delphi consensus for procedural preparation and consent

BACKGROUND

Despite the promise of oral immunotherapy (OIT) to treat food allergies, this procedure is associated with potential risk. There is no current agreement about what elements should be included in the preparatory or consent process.

OBJECTIVE

We developed consensus recommendations about the OIT process considerations and patient-specific factors that should be addressed before initiating OIT and developed a consensus OIT consent process and information form.

METHODS

We convened a 36-member Preparing Patients for Oral Immunotherapy (PPOINT) panel of allergy experts to develop a consensus OIT patient preparation, informed consent process, and framework form. Consensus for themes and statements was reached using Delphi methodology, and the consent information form was developed.

RESULTS

The expert panel reached consensus for 4 themes and 103 statements specific to OIT preparatory procedures, of which 76 statements reached consensus for inclusion specific to the following themes: general considerations for counseling patients about OIT; patient- and family-specific factors that should be addressed before initiating OIT and during OIT; indications for initiating OIT; and potential contraindications and precautions for OIT. The panel reached consensus on 9 OIT consent form themes: benefits, risks, outcomes, alternatives, risk mitigation, difficulties/challenges, discontinuation, office policies, and long-term management. From these themes, 219 statements were proposed, of which 189 reached consensus, and 71 were included on the consent information form.

CONCLUSION

We developed consensus recommendations to prepare and counsel patients for safe and effective OIT in clinical practice with evidence-based risk mitigation. Adoption of these recommendations may help standardize clinical care and improve patient outcomes and quality of life.

Age-Related Food Aversion and Anxiety Represent Primary Patient Barriers to Food Oral Immunotherapy

BACKGROUND

Although oral immunotherapy (OIT) for food allergy is a reasonable treatment option, barriers to this procedure's implementation have not been extensively evaluated from a patient perspective.

OBJECTIVE

We evaluated the barriers patients face during OIT administration, including anxiety and taste aversion, and the role of health care professionals, especially dietitians.

METHODS

A survey in Canada and the United States involved families currently enrolled in food OIT programs.

RESULTS

Of responses from 379 participants, fear of reaction was the most common barrier to OIT initiation, with 45.6% reporting it being a "very significant" barrier with other fears reported. However, taste aversion represented the prominent obstacle to continuation. Taste aversion was associated with a slower buildup (P = .02) and a reduction in dose (P = .002). Taste aversion was a strongly age-dependent barrier for initiation (P < .001) and continuation (P < .002), with older children over 6 years of age reporting it as a very significant barrier (P < .001). Boredom was reported as a concern for specific allergens such as peanut, egg, sesame, and hazelnuts (P < .05), emphasizing the need for diverse food options. Notably, 59.9% of respondents mixed OIT foods with sweet items. Despite these dietary concerns, dietitians were underutilized, with only 9.5% of respondents having seen a dietitian and the majority finding dietitian support helpful with greater certainty about the exact dose (P < .001).

CONCLUSIONS

Taste aversion and anxiety represent primary patient-related barriers to OIT. Taste aversion was highly age dependent, with older patients being more affected. Dietitians and psychology support were underutilized, representing a critical target to improve adherence and OIT success.

Bruton's tyrosine kinase inhibition for the treatment of allergic disorders

IgE signaling through its high-affinity receptor FcεRI is central to the pathogenesis of numerous allergic disorders. Oral inhibitors of Bruton's tyrosine kinase (BTKis), which are currently Food and Drug Administration-approved for treating B cell malignancies, broadly inhibit the FcεRI pathway in human mast cells and basophils, and therefore may be effective allergen-independent therapies for a variety of allergic diseases. The application of these drugs to the allergy space was previously limited by the low kinase selectivity and subsequent toxicities of early-generation compounds. Fortunately, next-generation, highly selective BTKis in clinical development appear to have more favorable risk-benefit profiles, and their likelihood of being Food and Drug Administration-approved for an allergy indication is increasing. Recent clinical trials have indicated the remarkable and rapid efficacy of the second-generation BTKi acalabrutinib in preventing clinical reactivity to peanut ingestion in adults with peanut allergy. In addition, next-generation BTKis including remibrutinib effectively reduce disease activity in patients with antihistamine-refractory chronic spontaneous urticaria. Finally, several BTKis are currently under investigation in early clinical trials for atopic dermatitis and asthma. In this review, we summarize recent data supporting the use of these drugs as novel therapies in food allergy, anaphylaxis, urticaria, and other allergic disorders. We also discuss safety data derived from trials using both short-term and chronic dosing of BTKis.

Mobile App/Web Platform for Monitoring Food Oral Immunotherapy in Children: Longitudinal Clinical Validation Study

BACKGROUND

Milk and egg allergies significantly impact the quality of life, particularly in children. In this regard, food oral immunotherapy (OIT) has emerged as an effective treatment option; however, the occurrence of frequent adverse reactions poses a challenge, necessitating close monitoring during treatment.

OBJECTIVE

This study aims to evaluate the ability of a new mobile/web app called OITcontrol to monitor milk and egg OIT.

METHODS

Patients undergoing milk or egg OIT were recruited and divided into 2 groups: the active group used the OITcontrol app in conjunction with standard written monitoring methods, whereas the control group relied solely on written diaries. Investigators documented hospital doses, hospital reactions, and administered treatments on the website. Patients recorded their daily allergen home-dose intake, home reactions, and administered treatments using the app. The following variables were compared between both groups: number and severity of hospital and reported home reactions, patient's adhesion to the OITcontrol app or written diary or both in terms of daily home-dose intake and home reactions recording, and treatment and dose adjustment compliance at home in case of reaction.

RESULTS

Sixteen patients were assigned to be monitored using the OITcontrol app along with additional written methods (active group), while 14 patients relied solely on a written paper diary (control group). A similar distribution was observed in terms of sex, age, basal characteristics, allergen treated in OIT, premedication, and sensitization profile. Active patients reported a comparable number of hospital and home reactions compared with the control group. In terms of recording system usage, 13/16 (81%) active patients used the OITcontrol app, while 10/14 (71%) control patients relied on the written diary. Among active patients, 6/16 (38%) used both methods, and 1 active patient used only written methods. However, control patients recorded home reactions more frequently than active patients (P=.009). Among active patients, the app was the preferred method for recording reactions (59/86, 69%), compared with the written diary (15/86, 17%) or both methods (12/86, 14%; P<.001). Treatment compliance in home-recorded reactions was similar between both groups (P=.15). However, treatment indications after an adverse reaction were more frequently followed (P=.04) in reactions recorded solely in the app (36/59, 61%) than in the written diary (29/71, 41%) or both systems (4/12, 33%). Moreover, compliance with dose adjustments after a moderate-severe reaction in home-recorded reactions was higher in the active group than in the control group (P<.001). Home reactions recorded only in the app (16/19, 84%) were more likely to follow dose adjustments (P<.001) than those recorded in the written diary (3/20, 15%) or using both methods (2/3, 67%).

CONCLUSIONS

The OITcontrol app appears to be a valuable tool for monitoring OIT treatment in children with food allergies. It proves to be a suitable method for recording daily home dose intakes and reactions, and it seems to enhance adherence to treatment indications following an adverse reaction as well as compliance with dose adjustments in home reactions. However, additional studies are necessary to comprehensively grasp the benefits and limitations of using the OITcontrol app in the management of OIT.

Fatal food anaphylaxis in adults and children

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

Comprehensive Diagnosis, Management, and Treatment of Sesame Allergy

Sesame allergy prevalence varies regionally and by age, in the range of 0.1% to 0.9%. Reactions can be severe and potentially fatal. Resolution rates are in the range of 20% to 50%. The diagnosis requires a careful history and the use of tests, such as skin prick tests and serum sesame-specific IgE. The availability of serum IgE testing for the sesame protein Ses i 1 has improved diagnostic accuracy. The emerging potential for sesame basophil activation tests and additional new tests will likely improve diagnosis in coming years, further reducing the need for diagnostic oral food challenges. Although sesame proteins share homology with those in many foods, clinically relevant cross-reactivity appears uncommon. Nevertheless, sesame is a prominent allergen for those with multiple food allergies. Management may include strict avoidance, but sesame products vary dramatically in protein content. Many people with sesame allergy tolerate forms that are low in protein, such as scattered seeds, rather than sesame paste that is protein-dense. Thus, options in the approach to avoidance are possible. Studies suggest that sesame oral immunotherapy may be safe and effective, and this and additional treatment options are emerging. Here, we review the current comprehensive diagnosis, management, and treatment for sesame allergy.

Primary, secondary and tertiary prevention of food allergy: current practices and future directions

The incidence of food allergies has risen around the globe, and experts have been exploring methods of preventing such allergies in young children to ease the burden of disease and reduce the morbidity and mortality caused by anaphylaxis to food allergens. Such preventative measures can be categorised as primary, secondary and tertiary prevention, which are discussed in detail in this review. Primary prevention is defined as the prevention of becoming sensitised towards specific allergens. The evidence suggests that avoiding common allergenic foods during pregnancy and breastfeeding is not protective against food allergies, and guidelines recommend weaning from 4 to 6 months of age, with recent studies supporting the early introduction of peanuts at 4 months to prevent peanut allergy. Secondary prevention targets patients who are already sensitised and aims to halt the progression of sensitisation, with evidence for high rates of success and safety in trials of early introduction to milk and peanuts using oral immunotherapy in sensitised infants. Tertiary allergy prevention focuses on reducing the risk of a patient having anaphylaxis, with oral immunotherapy being the most common method of promoting tolerance in allergic children. Several studies have demonstrated successful reintroduction for milk, egg and peanut; however, no such guidelines are recommended for other foods. Finally, dietary advancement therapy in the form of milk and egg ladders has been employed as a method of primary, secondary and tertiary prevention of allergies, particularly in Ireland, the UK and Canada.

Initial updosing phase of oral immunotherapy improves quality of life and psychological burden in parents of children with food allergy

Background: Oral immunotherapy (OIT) can impose psychological burdens on patients and their parents due to the necessary preparations and repeated adverse reactions. Objective: To investigate changes in quality of life (QoL) and psychological burden in parents of children receiving OIT for food allergy (FA). Methods: Children aged 3-13 years with FA were enrolled. Parents were asked to fill out the Korean versions of the Food Allergy Quality of Life-Parental Burden (FAQL-PB), the Korean versions of the Food Allergy Quality of Life-Parental Form (K-FAQLQ-PF), the Korean versions of the Beck Anxiety Inventory (K-BAI), and the Korean version of the Patient Health Questionnaire-9 (PHQ-9) for depression before OIT (T1), after 2 months of updosing (T2), and after the end of the updosing phase (T3). Results: A total of 111 parents were enrolled. The total FAQL-PB scores were decreased at T2 and T3 compared with those at T1 (all p < 0.001). Greater improvement in the total FAQL-PB score at T2 was noted in parents with a higher parental burden (FAQL-PB score ≥ 74 points) at baseline than in those with a lower parental burden (p = 0.001). Among the K-FAQLQ-PF domains, "food anxiety" scores were decreased at T2 and T3 compared with those at T1 (p = 0.049 and p = 0.030, respectively), whereas there was no change in "social and dietary limitation" and "emotional impact" scores between T1 and T2 and between T1 and T3. However, no differences were observed in K-BAI and PHQ-9 scores between T1 and T2 and between T1 and T3. Conclusion: Our results suggest that OIT improves parental burden and QoL in parents of children with FA.

Practical issues of oral immunotherapy for egg or milk allergy

Oral immunotherapy (OIT) has been recommended to reduce parental burden related to strict allergen avoidance and induce desensitization and immune tolerance for patients with long-lasting allergies to hen's eggs (HE) or cow's milk (CM). OIT should be monitored by pediatric allergists specializing in OIT and oral food challenge tests to manage allergic reactions. Although a previous history of anaphylaxis or multiple food allergies is not a contraindication to OIT, it is contraindicated if the patient has uncontrolled asthma, a malignancy, active systemic autoimmune disorders, or diseases requiring treatment with beta-blockers. A variety of OIT protocols have been de veloped to ensure better outcomes and safe up-dosing, including adjunctive therapies with biologics. This review provides insight into the practical issues of various immunotherapy options for children with HE or CM allergies.

Low-dose oral immunotherapy in immunoglobulin E-mediated food allergies

Nowadays, the management of food allergies has increasingly moved from conventional oral immunotherapy (OIT) to low-dose OIT or low-dose OIT utilizing hypoallergenic foods. This shift is largely because the latter appears to induce oral tolerance with fewer adverse effects than the former. However, the mechanisms underpinning such differences remain unclear. To better understand these mechanisms, we conducted a comparative study scrutinizing the mechanisms of OIT, especially those of low-dose desensitization. We also summarized articles on low-dose OIT and low-dose OIT using hypoallergenic foods. We examined the efficacy, safety, and immunological parameters of low-dose OIT and those of low-dose OIT with hypoallergenic foods with the aim of shedding some light on low-dose OIT and its therapeutic application in inducing oral tolerance for individuals with food allergies.

Addressing common questions on food oral immunotherapy: a practical guide for paediatricians

Food allergy has been increasing in prevalence in most westernised countries and poses a significant burden to patients and families; dietary and social limitations as well as psychosocial and economic burden affect daily activities, resulting in decreased quality of life. Food oral immunotherapy (food-OIT) has emerged as an active form of treatment, with multiple benefits such as increasing the threshold of reactivity to the allergenic food, decreasing reaction severity on accidental exposures, expanding dietary choices, reducing anxiety and generally improving quality of life. Risks associated with food immunotherapy mostly consist of allergic reactions during therapy. While the therapy is generally considered both safe and effective, patients and families must be informed of the aforementioned risks, understand them, and be willing to accept and hedge these risks as being worthwhile and outweighed by the anticipated benefits through a process of shared decision-making. Food-OIT is a good example of a preference-sensitive care paradigm, given candidates for this therapy must consider multiple trade-offs for what is considered an optional therapy for food allergy compared with avoidance. Additionally, clinicians who discuss OIT should remain increasingly aware of the growing impact of social media on medical decision-making and be prepared to counter misconceptions by providing clear evidence-based information during in-person encounters, on their website, and through printed information that families can take home and review.

Food Allergen Immunotherapy in the Treatment of Patients with IgE-Mediated Food Allergy

The prevalence of allergic diseases, including food allergy, is increasing, especially in developed countries. Implementation of an elimination diet is not a sufficient therapeutic strategy in patients with food allergy, whose quality of life is significantly impaired. In recent years, new effective therapeutic strategies have been developed, such as the application of oral, sublingual, and epicutaneous immunotherapy. Oral immunotherapy is the most often applied strategy because of its effectiveness and ease of application, with an acceptable safety profile. The effectiveness of oral immunotherapy in patients with egg, cow's milk, and peanut allergy has been proven both in terms of raising of the threshold and the development of tolerance, and in some patients, the development of sustainable unresponsiveness. Although oral immunotherapy is an effective treatment for food allergy, several limitations, including a long duration and a significant rate of reported adverse events, reduces its success. Therefore, new therapeutic options, such as treatment with biologicals, either as combinations with food allergen immunotherapy or as monotherapy with the aim of improving the efficacy and safety of treatment, are being investigated.

Gut microbiota and fecal metabolites in sustained unresponsiveness by oral immunotherapy in school-age children with cow's milk allergy

BACKGROUND

Oral immunotherapy (OIT) can ameliorate cow's milk allergy (CMA); however, the achievement of sustained unresponsiveness (SU) is challenging. Regarding the pathogenesis of CMA, recent studies have shown the importance of gut microbiota (Mb) and fecal water-soluble metabolites (WSMs), which prompted us to determine the change in clinical and gut environmental factors important for acquiring SU after OIT for CMA.

METHODS

We conducted an ancillary cohort study of a multicenter randomized, parallel-group, delayed-start design study on 32 school-age children with IgE-mediated CMA who underwent OIT for 13 months. We defined SU as the ability to consume cow's milk exceeding the target dose in a double-blind placebo-controlled food challenge after OIT followed by a 2-week-avoidance. We longitudinally collected 175 fecal specimens and clustered the microbiome and metabolome data into 29 Mb- and 12 WSM-modules.

RESULTS

During OIT, immunological factors improved in all participants. However, of the 32 participants, 4 withdrew because of adverse events, and only 7 were judged SU. Gut environmental factors shifted during OIT, but only in the beginning, and returned to the baseline at the end. Of these factors, milk- and casein-specific IgE and the Bifidobacterium-dominant module were associated with SU (milk- and casein-specific IgE; OR for 10 kUA/L increments, 0.67 and 0.66; 95%CI, 0.41-0.93 and 0.42-0.90; Bifidobacterium-dominant module; OR for 0.01 increments, 1.40; 95%CI, 1.10-2.03), and these associations were observed until the end of OIT.

CONCLUSIONS

In this study, we identified the clinical and gut environmental factors associated with SU acquisition in CM-OIT.

The Art of Immunotherapy

Selection of a patient with rhinitis/conjunctivitis or asthma for allergy immunotherapy (AIT) requires several decisions. First, does the patient's sensitization, pattern of exposure to an allergen, and degree of exposure to that allergen reasonably suggest a causal relationship? Does the level and duration of symptoms warrant the cost and inconvenience of immunotherapy, or is the patient motivated by the disease-modifying potential of AIT? If AIT is selected, is the choice to be greater safety and convenience with sublingual immunotherapy (SLIT) tablets, but with treatment probably limited to 2 or 3 allergens, or for subcutaneous immunotherapy where multiple allergen therapy is the rule and efficacy may be somewhat greater, at least initially, or does the physician go off-label into the unknowns of liquid SLIT? Are there extracts of sufficient potency to achieve likely effective doses? How does the physician deal with large local or systemic reactions, with gaps in treatment, with pollen seasons, and the use of premedication or cautionary prescription of epinephrine autoinjectors? How can adherence to AIT be improved? These and other questions are addressed in this paper.

[Introduction to food allergy]

Food allergy is a common chronic disorder that affects infants, children, adolescents, and adults. The prevalence of food allergy has increased in recent decades throughout the world, not limited to Western countries. Since there is no treatment, this focuses on avoiding allergens, in addition to educating patients and caregivers in the emergency treatment of acute reactions, for example: application of epinephrine. Studies suggest that accidental reactions occur in about 45% of children with food allergies each year, although most reactions are mild or moderate in severity. Hospital admissions for food anaphylaxis vary from 4 to 20 per 100,000 inhabitants; Deaths are rare, with an estimated incidence of 0.03 to 0.3 per million people with food allergy. Death from food anaphylaxis is rare and appears to have remained stable, possibly due to increases in food allergen labeling, diagnostic services, rates of intramuscular epinephrine prescription, and awareness of food allergies. Omalizumab is a drug approved for several disorders (chronic hives or difficult asthma) and may help reduce symptoms associated with food allergy. The relative importance of alternative technologies, management strategies and policies for food allergy varies from one region to another, due to differences in the epidemiology, education, socioeconomic well-being, and cultural preferences of the population.

Evaluation of peripheral basophil activation during exercise provocation test for desensitized patients

Some food allergic patients who have undergone oral immunotherapy develop exercise-induced allergic reactions on desensitization (EIARDs). This study investigated basophil activation status during the exercise provocation test (EPT) performed to diagnose EIARD. EPT was performed on 20 participants, and in vivo basophil activation status was analyzed using activation markers CD203c and CD63. The results showed that there was no significant difference between EPT-positive and negative subjects for basophil activation status throughout EPT. Consequently, in vivo basophil activation after ingestion of the causative food may not be associated with EIARDs. New tests are desired for predicting EIARDs.

Updates in food allergen immunotherapy

PURPOSE OF REVIEW

Food allergies are on the rise. Though allergen avoidance and management of acute reactions have been the backbone of therapy, complete avoidance and timely acute care is often not feasible. Food allergen immunotherapy (FAIT) is a novel and evolving treatment option intended to induce desensitization and potential sustained unresponsiveness (SU) to food allergens. This review addresses the methods, mechanisms, efficacy, and adverse effects of oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) for food allergens in the published literature.

RECENT FINDINGS

Single FAIT has been most extensively studied in peanut, milk, and hen's egg allergic patients and has been successful in achieving desensitization in treated individuals through various modalities. Long-term data regarding SU is limited; however, current data suggests subsets of patients may be more likely to achieve SU compared to others. Other studies are actively assessing multifood AIT and novel FAIT protocols with adjunctive therapies.

SUMMARY

Food allergy constitutes a prevalent problem with far-reaching consequences. The emergence of FAIT may mitigate the burden of food allergy. Current evidence is promising for specific allergens and pediatric patient populations. Future studies are needed to further assess efficacy between different modalities of immunotherapy for food allergens across an age continuum.

Eosinophil-Associated Gastrointestinal Manifestations During OIT

Gastrointestinal adverse events are common during oral immunotherapy (OIT) for food allergy and range from immediate IgE-mediated reactions to non-anaphylactic clinical presentations. This review aims to summarize recent findings on non-anaphylactic eosinophil-associated gastrointestinal adverse events during OIT. Two clinical presentations of non-anaphylactic eosinophil-associated gastrointestinal adverse events during OIT are identified, each with a different paradigm for treatment, and distinguished by their time of onset. In the first clinical entity, characterized by its onset early in the course of treatment, patients present with abdominal pain, nausea, and/or vomiting. The symptoms become evident typically within weeks to months of starting OIT. These symptoms, however, are not temporally related to the time of dose administration, as in the case of immediate IgE-mediated anaphylactic reactions. While esophageal biopsies, when performed, can demonstrate eosinophilic esophagitis (EoE), baseline esophageal eosinophilia has also been observed in food allergic patients prior to OIT. A potential non-invasive biomarker, the peripheral absolute eosinophil count (AEC), often rises during these reactions and subsides after dose reduction and subsequent resolution of symptoms. OIT can usually then be resumed, albeit at a slower pace, without a recurrence of symptoms. Risk factors for development of symptoms early during OIT include a high starting dose and a baseline AEC of greater than 600. The second, and much less frequently encountered, non-anaphylactic gastrointestinal adverse event related to OIT, presents months to years after initiating OIT. In this latter group, patients present with the classical clinical symptoms and endoscopic findings of EoE. In contrast to the acute onset group, peripheral eosinophilia is usually not observed in these cases. This OIT-associated EoE has shown good response to standard EoE treatment approaches of proton pump inhibitors or swallowed steroids. Most patients with eosinophil-associated adverse reactions are able to continue OIT and remain desensitized. Treatment approaches depend on the specific subtype of these reactions and relate to the stages of OIT treatment.

EAACI guidelines on the diagnosis of IgE-mediated food allergy

This European Academy of Allergy and Clinical Immunology guideline provides recommendations for diagnosing IgE-mediated food allergy and was developed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Food allergy diagnosis starts with an allergy-focused clinical history followed by tests to determine IgE sensitization, such as serum allergen-specific IgE (sIgE) and skin prick test (SPT), and the basophil activation test (BAT), if available. Evidence for IgE sensitization should be sought for any suspected foods. The diagnosis of allergy to some foods, such as peanut and cashew nut, is well supported by SPT and serum sIgE, whereas there are less data and the performance of these tests is poorer for other foods, such as wheat and soya. The measurement of sIgE to allergen components such as Ara h 2 from peanut, Cor a 14 from hazelnut and Ana o 3 from cashew can be useful to further support the diagnosis, especially in pollen-sensitized individuals. BAT to peanut and sesame can be used additionally. The reference standard for food allergy diagnosis is the oral food challenge (OFC). OFC should be performed in equivocal cases. For practical reasons, open challenges are suitable in most cases. Reassessment of food allergic children with allergy tests and/or OFCs periodically over time will enable reintroduction of food into the diet in the case of spontaneous acquisition of oral tolerance.

Exploring the potential and safety of quantum dots in allergy diagnostics

Biomedical investigations in nanotherapeutics and nanomedicine have recently intensified in pursuit of new therapies with improved efficacy. Quantum dots (QDs) are promising nanomaterials that possess a wide array of advantageous properties, including electronic properties, optical properties, and engineered biocompatibility under physiological conditions. Due to these characteristics, QDs are mainly used for biomedical labeling and theranostic (therapeutic-diagnostic) agents. QDs can be functionalized with ligands to facilitate their interaction with the immune system, specific IgE, and effector cell receptors. However, undesirable side effects such as hypersensitivity and toxicity may occur, requiring further assessment. This review systematically summarizes the potential uses of QDs in the allergy field. An overview of the definition and development of QDs is provided, along with the applications of QDs in allergy studies, including the detection of allergen-specific IgE (sIgE), food allergens, and sIgE in cellular tests. The potential treatment of allergies with QDs is also described, highlighting the toxicity and biocompatibility of these nanodevices. Finally, we discuss the current findings on the immunotoxicity of QDs. Several favorable points regarding the use of QDs for allergy diagnosis and treatment are noted.

Real-Life Use of Component-Specific IgE in IgE-Mediated Cow's Milk Protein Allergy in a Spanish Paediatric Allergy Centre

BACKGROUND

In Spain, IgE-mediated cow's milk protein allergy (CMPA) affects approximately 0.69% of infants. Molecular diagnosis may be useful for monitoring natural spontaneous tolerance development in CMPA. The aim of this study was to retrospectively analyse a cohort of paediatric patients with IgE-mediated CMPA who were avoiding milk products awaiting natural tolerance and determine the relationship between disease persistence and major cow's milk allergens.

METHODS

A retrospective chart review of 200 patients diagnosed with IgE-mediated CMPA between 2011 and 2020 was conducted. Patients strictly avoided milk products until an oral food challenge was performed. The main outcome was the introduction of liquid milk following a negative oral food challenge and its correlation with IgE and SPT measurements of milk components at diagnosis. Secondary outcomes included the rate of allergic reactions and anaphylaxis during the treatment period and its correlation with IgE and SPT measurements.

RESULTS

Of the 200 charts analysed, 122 patients had a negative oral food challenge to milk (61.0%) (95% confidence interval (CI): 54.1-67.5) following a period of strict avoidance of milk. Higher levels of component-specific IgE, especially casein, were associated with failure in the oral food challenge (p = 0.02). Allergic reactions were experienced by 106 children (53%), of which 34 (17%; 95% CI: 12.4-22.8) had anaphylactic reactions. The risk of anaphylaxis was not predicted by raised IgE levels.

CONCLUSIONS

While a large proportion of children acquired natural tolerance to cow's milk following a period of strict avoidance, IgE-mediated CMPA persisted in many children. Casein IgE levels at diagnosis were raised in those who failed to achieve natural tolerance. Allergic reactions to milk, including anaphylaxis, occurred commonly, but this was not predicted by raised IgE levels or SPT measurements.

Food oral immunotherapy: Any distinguishing factors predicting the need of anti-IgE?

Oral immunotherapy (OIT) has gained popularity recently for IgE-mediated food allergy. Omalizumab (OMZ) has been used in patients (10-20%) who have too severe/frequent allergic reactions (AR) to continue OIT, to reduce these reactions. In this study, it was aimed to compare two groups of patients who completed OIT with and without OMZ and to seek determinants predicting the need of this treatment. It was also aimed to share the clinical findings regarding the long-term use of OMZ and the withdrawal process. Forty-one patients were started OIT and 93% could be desensitized. Two groups were similar in means of demographic characteristics, and clinical and laboratory findings. The patients who needed OMZ during OIT had also lower reaction doses during oral challenge (p = 0.037). Higher AR rate in this group declined after starting OMZ (p < 0.001). The injection intervals of OMZ were gradually extended. Most patients were able to discontinue OMZ (81%). There were no severe reactions during drug withdrawal attempts. The low reaction thresholds during oral food challenge may give a clue about OMZ requirement during OIT. It may be an option to start the treatment before OIT if reaction was seen in the first few steps of the oral food challenge. For the sake of safety, extension of injection intervals should be preferred instead of abruptly stopping OMZ.

Behavioral changes of food allergic model mice during light and dark period

Although an animal model of food allergy has been used to investigate its progression mechanism, most researcher could not assess its symptoms for long especially under dark environment. We assessed the behavioral changes of food allergic mice using an image analysis system to track a mouse under both light and dark environments. Mice were sensitized with intraperitoneal ovalbumin (OVA) injections and challenged ten times with oral OVA administration. The OVA challenges induced weight loss and diarrhea. We assessed their behavior and found that the OVA challenges decreased their total moving distance during the dark period. We also revealed that the OVA challenges increased the inactive time of mice during the dark period. Interestingly, these changes were not observed or very small during the light period. We next assessed the location of mice in the home-cage and found that the OVA challenges increased the time when mice stayed at corners and decreased the time at the center during the dark period. These observations suggest mental abnormality of mice. Indeed, the OVA challenges increased the immobility time of mice in the tail suspension test. Thus, food allergic mice exhibited reduced activity and might exhibit psychological symptoms during dark period.

Oral immunotherapy as a curative treatment for food-allergic preschool children: Current evidence and potential underlying mechanisms

The worldwide rising prevalence of food allergy is a major public health concern. Standard care consists of allergen avoidance and rescue medication upon accidental exposure. Oral immunotherapy (OIT) is increasingly being studied as a treatment option. Although desensitization (an increased reaction threshold) is often achieved during OIT, sustained unresponsiveness (SU; clinical nonreactivity after finishing OIT) is not achieved in most patients. A few studies have investigated the effectiveness of OIT in children younger than 4 years of age (early = e-OIT) and have shown a much more favorable outcome in terms of SU development. Together with food allergy prevention studies, which have demonstrated high efficacy of early oral allergen exposure, the outcomes of e-OIT studies indicate an early-life window of opportunity to achieve SU, allowing unrestricted dietary intake. However, the underlying mechanism of the high effectiveness of e-OIT is not understood yet. Both cohort and OIT studies indicate early-life immune plasticity. An immature food-allergic response in the first years of life seems to be a major driver of this immune plasticity, along with a higher tolerogenic immunological state. Allergy maturation can likely be disrupted effectively by early intervention, preventing the development of persistent food allergy. Upcoming studies will provide important additional data on the safety, feasibility, and effectiveness of e-OIT. Combined with immune mechanistic studies, this should inform the implementation of e-OIT.

KAAACI Guidelines for Allergen Immunotherapy

Allergen immunotherapy (AIT) is a causative treatment for various allergic diseases such as allergic rhinitis, allergic asthma, and bee venom allergy that induces tolerance to offending allergens. The need for uniform practice guidelines in AIT is continuously growing because of the increasing discovery of potential candidates for AIT and evolving interest in new therapeutic approaches. This guideline is an updated version of the Korean Academy of Asthma Allergy and Clinical Immunology recommendations for AIT published in 2010. This updated guideline proposes an expert opinion by allergy, pediatrics, and otorhinolaryngology specialists with an extensive literature review. The guideline deals with basic knowledge and methodological aspects of AIT, including mechanisms, clinical efficacy, patient selection, allergens extract selection, schedule and doses, management of adverse reactions, efficacy measurements, and special consideration in pediatrics. The guidelines for sublingual immunotherapy will be covered in detail in a separate article.

Immune signatures predicting the clinical outcome of peanut oral immunotherapy: where we stand

Peanut allergy is a growing health concern that can cause mild to severe anaphylaxis as well as reduced quality of life in patients and their families. Oral immunotherapy is an important therapeutic intervention that aims to reshape the immune system toward a higher threshold dose reactivity and sustained unresponsiveness in some patients. From an immunological point of view, young patients, especially those under 3 years old, seem to have the best chance for therapy success. To date, surrogate markers for therapy duration and response are evasive. We provide a comprehensive overview of the current literature state regarding immune signatures evolving over the course of oral immunotherapy as well as baseline immune conditions prior to the initiation of treatment. Although research comparing clinical and immune traits in the first years of life vs. later stages across different age groups is limited, promising insights are available on immunological endotypes among peanut-allergic patients. The available data call for continued research to fill in gaps in knowledge, possibly in an integrated manner, to design novel precision health approaches for advanced therapeutic interventions in peanut allergy.

Food Immunotherapy: Dissecting Current Guidelines and Navigating the Gray Zone

Food allergy is a common, chronic disease that is burdensome for patients and families, with multiple dietary and social limitations and a significant psychological impact stemming from the fear of accidental exposures and potentially severe, life-threatening reactions. Until recently, the only management option consisted of strict food avoidance. Food allergen immunotherapy (food AIT) has emerged as an alternative, active intervention to strict food avoidance, with a multitude of research studies supporting its efficacy and good safety profile. Food AIT results in a raise of allergenic threshold, which provides several benefits to food-allergic patients, including protection from accidental exposures, potentially decreased severity of allergic reactions on unintentional exposures, and improvement in quality of life. In the last few years, multiple independent reports have been published proposing strategies to implement food oral immunotherapy in U.S. clinics, although formal guidelines are currently lacking. Because food immunotherapy is gaining traction, popularity, and interest among both patients and health care providers, many physicians look for guidance on how to implement this intervention in their daily practice. In other parts of the world, use of this treatment has prompted the development of various guidelines from allergy societies. This rostrum discusses currently available guidelines on food AIT from different areas of the world, describes and comments on their similarities and differences, and highlights unmet needs in this area of therapy.

Biologics to treat anaphylaxis

PURPOSE OF REVIEW

The purpose of this literature review was to review the latest use of biologics in the management of anaphylaxis. The methodology was to highlight both the nonbiologic management of anaphylaxis and the biologic management and how they can be used in conjunction with each other.

RECENT FINDINGS

As the phenotypes and endotypes of anaphylaxis are better portrayed, it furthers our understanding of the mechanisms of anaphylaxis. New applications of existing biologics to the prevention of anaphylaxis are described.

SUMMARY

Anaphylaxis is a potentially life-threatening acute hypersensitivity reaction affecting up to 16.8% of the U.S. population. Acute management entails swift identification, removal of the causative agent, and the prevention of cardiovascular collapse, firstly with epinephrine. Adjunctive treatments such as antihistamines work to prevent anaphylaxis from recurring. Biologic management of anaphylaxis involves the use of large-molecule drugs such as monoclonal antibodies. Omalizumab, an IgG1 monoclonal antibody targeting unbound IgE, is the most prevalent and widely studied biologic in the prevention of anaphylaxis. Other monoclonal antibodies in development or approved for other indications, such as ligelizumab, quilizumab, MEDI4212, and dupilumab, may also have potential for preventing anaphylaxis through various mechanisms.

Modulation of immune response by nanoparticle-based immunotherapy against food allergens

The increasing prevalence of food allergies worldwide and the subsequent life-threatening anaphylactic reactions often have sparse treatment options, providing only symptomatic relief. Great strides have been made in research and in clinics in recent years to offer novel therapies for the treatment of allergic disorders. However, current allergen immunotherapy has its own shortcomings in terms of long-term efficacy and safety, due to the local side effects and the possibility of anaphylaxis. Allergen-specific immunotherapy is an established therapy in treating allergic asthma, allergic rhinitis, and allergic conjunctivitis. It acts through the downregulation of T cell, and IgE-mediated reactions, as well as desensitization, a process of food tolerance without any allergic events. This would result in a protective reaction that lasts for approximately 3 years, even after the withdrawal of therapy. Furthermore, allergen-specific immunotherapy also exploits several routes such as oral, sublingual, and epicutaneous immunotherapy. As the safety and efficacy of allergen immunotherapy are still under research, the exploration of newer routes such as intra-lymphatic immunotherapy would address unfulfilled needs. In addition, the existence of nanoparticles can be exploited immensely in allergen immunotherapy, which would lead to safer and efficacious therapy. This manuscript highlights a novel drug delivery method for allergen-specific immunotherapy that involves the administration of specific allergens to the patients in gradual increasing doses, to induce desensitization and tolerance, as well as emphasizing different routes of administration, mechanism, and the application of nanoparticles in allergen-specific immunotherapy.

Immune response evolution in peanut epicutaneous immunotherapy for peanut-allergic children

BACKGROUND

Epicutaneous immunotherapy with investigational Viaskin™ Peanut 250 μg (DBV712) has demonstrated statistically superior desensitization versus placebo in peanut-allergic children in clinical trials. It is unclear whether serologic biomarkers predict response.

METHODS

Serum-specific IgG4 and IgE (whole peanut and components) from subjects enrolled in the phase 3 Efficacy and Safety of Viaskin Peanut in Children With IgE-Mediated Peanut Allergy study were examined by exploratory univariate and multivariate analyses to determine trajectories and predictors of treatment response, based upon peanut protein eliciting dose (ED) at Month (M) 12 double-blind placebo-controlled food challenge.

RESULTS

Among Viaskin Peanut-treated subjects, peanut sIgG4 significantly increased from baseline through M12 and peanut sIgE peaked at M3 and fell below baseline by M12, with sIgG4 and sIgE peanut components mirroring these trajectories. Placebo subjects had no significant changes. By univariate analysis, M12 peanut sIgG4/sIgE was higher in treatment responders (p < 0.001) and had highest area under the curve (AUC) for predicting ED ≥300 mg and ≥1000 mg (AUC 69.5% and 69.9%, respectively). M12 peanut sIgG4/sIgE >20.1 predicted M12 ED ≥300 mg (80% positive predictive value). The best performing component was Ara h 1 sIgE <15.7 kUA /L (AUC 66.5%). A multivariate model combining Ara h 1 and peanut sIgG4/sIgE had an AUC of 68.2% (ED ≥300 mg) and 67.8% (ED ≥1000 mg).

CONCLUSIONS

Peanut sIgG4 rise most clearly differentiated Viaskin Peanut versus placebo subjects. sIgG4/sIgE ratios >20.1 and the combination of Ara h 1 and peanut sIgG4/sIgE had moderate ability to predict treatment response and could potentially be useful for clinical monitoring. Additional data are needed to confirm these relationships.

An update on recent developments and highlights in food allergy

While both the incidence and general awareness of food allergies is increasing, the variety and clinical availability of therapeutics remain limited. Therefore, investigations into the potential factors contributing to the development of food allergy (FA) and the mechanisms of natural tolerance or induced desensitization are required. In addition, a detailed understanding of the pathophysiology of food allergies is needed to generate compelling, enduring, and safe treatment options. New findings regarding the contribution of barrier function, the effect of emollient interventions, mechanisms of allergen recognition, and the contributions of specific immune cell subsets through rodent models and human clinical studies provide novel insights. With the first approved treatment for peanut allergy, the clinical management of FA is evolving toward less intensive, alternative approaches involving fixed doses, lower maintenance dose targets, coadministration of biologicals, adjuvants, and tolerance-inducing formulations. The ultimate goal is to improve immunotherapy and develop precision-based medicine via risk phenotyping allowing optimal treatment for each food-allergic patient.

Severe Anaphylactic Reactions to Home Doses of Oral Immunotherapy for Food Allergy

BACKGROUND

Severe anaphylactic reactions to home doses may occur during food allergy oral immunotherapy (OIT).

OBJECTIVE

To study the rate and risk factors for such reactions.

METHODS

We studied all patients aged greater than 3.5 years who completed OIT in a single center between April 2010 and January 2020. All home epinephrine-treated reactions (HETRs) were identified. High-grade HETRs (HG-HETRs) were defined as HETRs involving respiratory (SpO2 of 94% or less), cardiovascular (low blood pressure), or central nervous system impairment (loss of consciousness). We investigated the rate and risk factors for HG-HETRs.

RESULTS

A total of 1,637 OIT treatments were studied: milk (880), peanut (346), tree nuts (221), sesame (115), and egg (75). Of 390 identified HETRs, 30 HG-HETRs occurred during 27 treatments (1.65% of all treatments). Nearly all (26 of 30) were during milk OIT in patients with house dust mite (HDM) sensitization and asthma (26 of 30 each). Of the 30 patients with HG-HETRs, 21 recovered with one or two epinephrine treatments, but nine (0.55% of all treatments) did not respond to a second dose of epinephrine and were deemed to have refractory anaphylaxis. Three patients required intensive care unit admission and three received epinephrine drip, but none required ventilatory support. Risk factors for HG-HETRs included milk OIT (P = .031), asthma (P = .02) and HDM sensitization (P = .02). No specific triggers for HG-HETR were identified. Of patients with HG-HETRs, 25.9% were fully desensitized, including the four non-milk treated patients; 22.2% were partially desensitized; and 51.9% failed.

CONCLUSIONS

High-grade HETRs are uncommon, particularly refractory anaphylactic reactions to home OIT doses. Although milk OIT, asthma, and HDM sensitization are the main risk factors for such reactions, identification of patients who are at risk is challenging.

The future of food allergy: Challenging existing paradigms of clinical practice

The field of food allergy has seen tremendous change over the past 5-10 years with seminal studies redefining our approach to prevention and management and novel testing modalities in the horizon. Early introduction of allergenic foods is now recommended, challenging the previous paradigm of restrictive avoidance. The management of food allergy has shifted from a passive avoidance approach to active interventions that aim to provide protection from accidental exposures, decrease allergic reaction severity and improve the quality of life of food-allergic patients and their families. Additionally, novel diagnostic tools are making their way into clinical practice with the goal to reduce the need for food challenges and assist physicians in the-often complex-diagnostic process. With all the new developments and available choices for diagnosis, prevention and therapy, shared decision-making has become a key part of medical consultation, enabling patients to make the right choice for them, based on their values and preferences. Communication with patients has also become more complex over time, as patients are seeking advice online and through social media, but the information found online may be outdated, incorrect, or lacking in context. The role of the allergist has evolved to embrace all the above exciting developments and provide patients with the optimal care that fits their needs. In this review, we discuss recent developments as well as the evolution of the field of food allergy in the next decade.

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.

A new experimental model to study shrimp allergy

Shrimp is among the most sensitizing food allergens and has been associated with many anaphylaxis reactions. However, there is still a shortage of studies that enable a systematic understanding of this disease and the investigation of new therapeutic approaches. This study aimed to develop a new experimental model of shrimp allergy that could enable the evaluation of new prophylactic treatments. BALB/c mice were subcutaneously sensitized with 100 μg of shrimp proteins of Litopenaeus vannamei adsorbed in 1 mg of aluminum hydroxide on day 0, and a booster (100 µg of shrimp proteins only) on day 14. The oral challenge protocol was based on the addition of 5 mg/ml of shrimp proteins to water from day 21 to day 35. Analysis of shrimp extract content detected at least 4 of the major allergens reported to L. vannamei. In response to the sensitization, allergic mice showed significantly enhanced IL-4 and IL-10 production in restimulated cervical draining lymph node cells. High detection of serum anti-shrimp IgE and IgG1 suggested the development of allergies to shrimp while Passive Cutaneous Anaphylaxis assay revealed an IgE-mediated response. Immunoblotting analysis revealed that Allergic mice developed antibodies to multiple antigens present in the shrimp extract. These observations were supported by the detection of anti-shrimp IgA production in intestinal lavage samples and morphometric intestinal mucosal changes. Therefore, this experimental protocol can be a tool to evaluate prophylactic and therapeutic approaches.

Clinical outcomes of efficacy in food allergen immunotherapy trials

PURPOSE OF REVIEW

With food allergy affecting millions of children worldwide, the consolidation of food allergen immunotherapy represents an encouraging therapeutic option, that might expand in the next few years to reach greater number of candidates. This review aims at providing a critical overview of the efficacy outcomes employed in food allergen immunotherapy trials (AIT).

RECENT FINDINGS

Understanding efficacy endpoints rely on identifying what and how these are being measured. Desensitization, as the efficacy of the therapy to increase the patient's reactivity threshold to the food during therapy, and Sustained Unresponsiveness, withholding such efficacy even if the therapy is withdrawn, are nowadays considered the main parameters of efficacy evaluation. Quality of life is a promising variable to capture food AIT impact from the patient's perspective.There is a relevant degree of heterogeneity across studies in outcomes definitions and also in oral food challenges design, the tool that is more spread to assess results, hampering study comparison.

SUMMARY

Interpreting the results of a clinical trial, and comparing data from different studies is an important task, both for the researcher and the clinician, that should be done after a careful analysis of the outcomes and the evaluation tools used.

Immunotherapy with Pru p 3 for food allergy to peach and non-specific lipid transfer protein: a systematic review

BACKGROUND

Non-specific lipid-transfer protein (nsLTP) is a pan-allergen in the plant world, and a cause of significant concern as food allergen in the Mediterranean area, due to its general heat- and acid-resistance and hence the risk of severe allergic reactions. Pru p 3, the peach nsLTP, is considered the primary sensitizer to this allergen family and this allergy is usually persistent. Allergen-free diet and acute treatment of manifestations are the main recognized management goals in food allergy.

MAIN TEXT

The role of immunotherapy for treating food allergy in adult patients is controversial, but immunotherapy for Pru p 3 could potentially represent a relevant therapeutic strategy. We systematically searched databases for studies assessing the role of immunotherapy Pru p 3 in food allergy. Overall, nine studies were included. Immunotherapy with Pru p 3 appears to be effective and with a good safety profile in both peach and LTP allergy for some foods, such as peanut, in both RCT and real-life studies.

CONCLUSIONS

Immunotherapy with Pru p 3 is a possible treatment option for food allergy to the peach LTP in the Mediterranean area, although at present have not reached routinary clinical practice. Larger studies are needed to confirm these findings and identify predictive biomarkers.

Eruption of Permanent Teeth As Risk Factor for Allergic Reactions During Oral Immunotherapy

Background: Oral immunotherapy (OIT) increases the threshold of reaction in children older than 4 years with food allergy. The risk for severe allergic reactions (ARs) during OIT has been reported in several studies, often in the presence of concomitant cofactors such as physical exercise, empty stomach, medications, poorly controlled asthma, menses, and alcohol consumption. Cases Presentation: We describe a case series of 5 scholar age patients undergoing OIT who showed ARs to a known, previously tolerated dose of allergen during permanent tooth eruption, in which other known cofactors were excluded. Conclusions: Patients may be exposed to cofactors due to behavioral habits not only in the second and third decades of life, but also in the first decade of life, due to the timing of mixed dentition. More studies are needed to estimate the frequency and entity of tooth eruption as cofactor, as well as to know the correct management of children undergoing dentition during OIT.