Update on food allergy

Towards an optimized model of food allergy in zebrafish

BACKGROUND

The prevalence of food allergies is on the rise, posing a significant challenge to public health. Rodents serve as the predominant animal model in food allergy research; yet, the application of rodent models proves to be a laborious and time-consuming endeavor. It is imperative to develop novel in vivo models.

METHODS

Ovalbumin (OVA) was administered as the allergen, following the recommended dosage used in other species. During the sensitization phase, a dosage of 0.25 mg per 10 tails per 1 L was administered twice daily, and during the challenge phase, the dosage was increased to 3 times the initial level. The study explored two dimensions of sensitization: the mode of exposure, which can be either continuous or intermittent, and the duration of exposure, which includes 3 days, 5 days, and 7 days. We examined midgut pathological changes, immunoglobulins contents, and mRNA expressions associated to T helper cells (Th) 2 cytokines following exposure.

RESULTS

A significant 109.3 % increase in the number of eosinophils was observed in the midgut histopathology following intermittent 5-day OVA exposure, which emerged as the most effective model. OVA exposure increased concentrations of immunoglobulin M (IgM) (105.2 %), IgZ (312.1 %), and IgD (304.3 %) in this model. The mRNA expressions of Th2-related interleukin (IL)-4 and IL-13 were also elevated by 132.8 % and 421.0 %, respectively.

CONCLUSION

The intermittent 5-day OVA exposure was suggested to be the best constructed zebrafish food allergy model, which may be a potential tool for research into food allergies.

Epidemiology of Paediatric Italian Food Allergy: Results of the EPIFA study

Background

Updated epidemiologic data are important for defining effective public health strategies for pediatric food allergy (FA).

Objective

The Epidemiology of Paediatric Italian Food Allergy (EPIFA) study was designed to investigate the epidemiology of pediatric FA in one of the most heavily populated Italian regions.

Methods

A retrospective cohort study was performed in collaboration with family pediatricians aimed at investigating the epidemiology of Italian pediatric FA during 2009 to 2021. Family pediatricians in the Campania region were invited to use the Google Forms platform for online compilation of data forms. Data forms were reviewed by experienced pediatric allergists at the coordinating center.

Results

A total population of 105,151 subjects (aged 0-14 years) was screened during the study period. Data from 752 FA patients were evaluated. A progressive increase in FA incidence and prevalence was observed from 2009 to 2021, with a relative increase up to 34% and 113.6%, respectively, at the end of study period. The relative increase in FA prevalence was higher in the 0-3-year-old age group in the same study period (+120.8%). The most frequent allergens were cow's milk, hen's egg, and nuts.

Conclusion

The results of the EPIFA study showed an increase in pediatric FA incidence and prevalence from 2009 to 2021 in Italy. These results underline the necessity of new effective strategies for preventing and managing these conditions.

A comprehensive review on novel synthetic foods: Potential risk factors, detection strategies, and processing technologies

Nowadays, the food industry is facing challenges due to the simultaneous rise in global warming, population, and food consumption. As the integration of synthetic biology and food science, novel synthetic foods have obtained high attention to address these issues. However, these novel foods may cause potential risks related to human health. Four types of novel synthetic foods, including plant-based foods, cultured meat, fermented foods, and microalgae-based foods, were reviewed in the study. The original food sources, consumer acceptance, advantages and disadvantages of these foods were discussed. Furthermore, potential risk factors, such as nutritional, biological, and chemical risk factors, associated with these foods were described and analyzed. Additionally, the current detection methods (e.g., enzyme-linked immunosorbent assay, biosensors, chromatography, polymerase chain reaction, isothermal amplification, and microfluidic technology) and processing technologies (e.g., microwave treatment, ohmic heating, steam explosion, high hydrostatic pressure, ultrasound, cold plasma, and supercritical carbon dioxide) were reviewed and discussed critically. Nonetheless, it is crucial to continue innovating and developing new detection and processing technologies to effectively evaluate these novel synthetic foods and ensure their safety. Finally, approaches to enhance the quality of these foods were briefly presented. It will provide insights into the development and management of novel synthetic foods for food industry.

Oral Immunotherapy: An Overview

Oral immunotherapy (OIT) is an alternative treatment of IgE-mediated food allergy that has been shown to increase tolerance threshold to many of the top food allergens, although this effect may be dependent on age, dose, frequency, and duration. OIT has been shown to be effective and safe in infants, and early initiation can improve rates of desensitization even for those foods whose natural history favors loss of allergy. Studies looking at protocol modification to improve OIT success are ongoing as is the evaluation of clinical tools to help monitor OIT effects.

[Declaration of allergens on food labels: overview of Latin AmericaDeclaração de alergênicos na rotulagem de alimentos: panorama da América Latina]

Objective

Identify countries that have legislation on mandatory declarations of food allergens, irradiated foods, and transgenic foods on the nutritional labels of packaged foods.

Methods

Exploratory study reviewing the health regulations and technical standards for foods in Latin American countries in order to gather information on declarations of allergens, trace allergens, irradiated foods, and transgenic foods. The information search was carried out through the countries' government web pages. Presentation of the results is descriptive and narrative.

Results

Of the 19 countries reviewed, 89% require a declaration of allergens on their nutrition labeling, 76% have legislation that explicitly require a statement on trace allergens, and 82% follow Codex Alimentarius recommendations with some modifications of food categories.

Conclusions

Three pending challenges in the Region are: requiring statements on allergens as a food safety measure; making progress toward improved labeling of trace allergens; and ensuring universal availability of epinephrine.

Elevated Immunoglobulin E Serum Levels: Possible Underlying Factors That Can Cause an Inborn Error of Immunity in the Pediatric Population with Recurrent Infections

Elevated immunoglobulin E (IgE) levels are commonly associated with allergies. However, high IgE levels are also found in several other infectious and non-infectious disorders. Elevated IgE levels typically suggest allergies, eczema, or recurrent skin infections. Hyperimmunoglobulin E (hyper-IgE) levels typically reflect a monogenic atopic condition or inborn immune defects with an atopic phenotype. The aim of our research is to investigate and observe the clinical characteristics of children with increased IgE levels who have previously manifested infectious diseases. Furthermore, the retrospective study considers other factors, such as demographic characteristics (sex, area/environment, and age), and their effect on IgE serum levels. To answer this question, we conducted a one-year hospital-based retrospective study that included 200 hospitalized children who had at least two viral or bacterial infections in the six months preceding hospitalization. Measurements of IgE and allergen panels (respiratory and digestive) using blood samples revealed that individuals who tested positive for the body's synthesis of hyper-IgE were not observably allergic to any potential allergens despite having higher total serum IgE. According to the results, there was a strong correlation between elevated IgE serum levels and a history of infectious diseases among the patients.

Purified Clinoptilolite-Tuff as an Efficient Sorbent for Food-Derived Peanut Allergens

The avoidance of allergen intake is crucial for persons affected by peanut allergy; however, the cross-contamination of food is common and leads to unpredictable consequences after the consumption of supposedly "safe" food. The aim of the present study was to eliminate harmful traces of peanut allergens from food using purified clinoptilolite-tuff (PCT)-a specially processed zeolite material. Analyses were performed using a peanut ELISA and a Coomassie blue (Bradford) assay. Mimicking conditions of the human gastrointestinal tract demonstrated a higher efficacy of PCT in the intestine (pH 6.8) than in the stomach (pH 1.5). Adsorption rates were fast (<2 min) and indicated high capacities (23 µg and 40 µg per 1 mg of PCT at pH 1.5 and pH 6.8, respectively). Allergenically relevant peanut protein concentrations were sorbed in artificial fluids (32 µg/mL by 4 mg/mL of PCT at pH 1.5 and 80.8 µg/mL by 0.25 mg/mL of PCT at pH 6.8) when imitating a daily dose of 2 g of PCT in an average stomach volume of 500 mL. Experiments focusing on the bioavailability of peanut protein attached to PCT revealed sustained sorption at pH 1.5 and only minor desorption at pH 6.8. Accompanied by gluten, peanut proteins showed competing binding characteristics with PCT. This study therefore demonstrates the potential of PCT in binding relevant quantities of peanut allergens during the digestion of peanut-contaminated food.

Serologic measurements for peanut allergy: Predicting clinical severity is complex

Allergist-immunologists use serologic peanut allergy testing to maximize test sensitivity and specificity while minimizing cost and inconvenience. Recent advances toward this goal include a better understanding of specific IgE (sIgE) and component testing, epitope-sIgE assays, and basophil activation testing. Predicting reaction severity with serologic testing is challenged by a range of co-factors that influence reaction severity, such as the amount and form of any allergen consumed and comorbid disease. In 2020, the Allergy Immunology Joint Task Force on Practice Parameters recommended Ara h 2-sIgE as the most cost-effective diagnostic test for peanut allergy because of its superior performance, when compared with skin prick testing and serum IgE. Basophil activation testing, a functional test of allergic response not evaluated in the Joint Task Force on Practice Parameters guideline, is a promising option for both allergy diagnosis and prognosis. Similarly, epitope-sIgE testing may improve prediction of reaction thresholds, but further validation is needed. Despite advances in food allergy testing, many of these tools remain limited by cost, accessibility, and feasibility. In addition, there is a need for further research on how atopic dermatitis may be modifying serologic food allergy severity assessments. Given these limitations, allergy test selection requires a shared decision-making approach so that a patient's values and preferences regarding financial impact, inconvenience, and psychological effects are considered in the context of clinician expertise on the timing and use of optimized testing.

Regular consumption following early introduction of allergenic foods and aggressive treatment of eczema are necessary for preventing the development of food allergy in children

PURPOSE OF REVIEW

Over the past two decades, food allergy prevention strategies have shifted from 'delayed introduction' to 'no delayed introduction' to 'early introduction' of allergenic foods. This article reviews important research in this field published in the early 2020s to support future strategies for food allergy prevention.

RECENT FINDINGS

Recent randomized controlled trials (RCTs), systematic reviews, meta-analyses, and real-world studies have reported that early allergenic food introduction, especially peanut and egg, are effective for preventing food allergies. However, there are also reports that food-induced anaphylaxis admission rates in infants are increasing.

SUMMARY

Early allergenic food introduction by itself is not sufficient to prevent the development of food allergies. Recent RCTs (SPADE study and COMEET study) have demonstrated that continued regular cow's milk consumption after early introduction is important for preventing the onset of cow's milk allergy. Furthermore, an RCT (PACI study) reported that early and aggressive anti-inflammatory topical therapy for eczema can contribute to the prevention of egg allergy by suppressing percutaneous sensitization. Food allergies may be prevented through a combination of early food introduction, regular consumption, and active eczema treatment. Further research is needed to develop well tolerated, effective, and practical strategies to prevent food allergies.

Differences in the Course, Diagnosis, and Treatment of Food Allergies Depending on Age-Comparison of Children and Adults

Food allergy (FA) has become a common global public health issue, with a growing prevalence in the modern world and a significant impact on the lives of patients, their families, and caregivers. It affects every area of life and is associated with elevated costs. Food allergy is an adverse immune reaction that occurs in response to a given food. The symptoms vary from mild to severe and can lead to anaphylaxis. This is why it is important to focus on the factors influencing the occurrence of food allergies, specific diagnostic methods, effective therapies, and especially prevention. Recently, many guidelines have emphasized the impact of introducing specific foods into a child's diet at an early age in order to prevent food allergies. Childhood allergies vary with age. In infants, the most common allergy is to cow's milk. Later in life, peanut allergy is more frequently diagnosed. Numerous common childhood allergies can be outgrown by adulthood. Adults can also develop new IgE-mediated FA. The gold standard for diagnosis is the oral provocation test. Skin prick tests, specific IgE measurements, and component-resolved diagnostic techniques are helpful in the diagnosis. Multiple different approaches are being tried as possible treatments, such as immunotherapy or monoclonal antibodies. This article focuses on the prevention and quality of life of allergic patients. This article aims to systematize the latest knowledge and highlight the differences between food allergies in pediatric and adult populations.

Major peanut allergens are quickly released from peanuts when seeds are hydrated under specific conditions

Allergens release from their biological source is a critical step in allergic sensitization. We sought to investigate in vitro the role of hydration at 1:10 w/v without stirring and 1:5 w/v with and without stirring on the release of major and minor allergens from peanut kernels. We hypothesized that hydration plays a pivotal role in peanut allergens release, affecting major allergens predominantly, and that peanut-water ratio and stirring influence allergen diffusion. We found that major peanut allergen Ara h 1 was quickly released during hydration leading to a decrease in its content in the seed particularly at hydration performed at 1:5 w/v with stirring. Ara h 2 remained more preserved in the hydrated seed, while Ara h 3 showed no content decrease despite its important release into the hydration water. Minor allergens Ara h 8 and Ara h 9 have lower abundance in peanut leading to a reduction of their content in the seed after their diffusion into the water during hydration. The results also demonstrated that a higher seed-to-water ratio (1:5 w/v) and stirring had a more pronounced impact on allergen release.

Risk Factors for Severe Seafood Allergy Among Adults in an Urban City in Vietnam

Purpose

Increasing seafood consumption is associated with more frequent reports of food allergy. Little is known about seafood allergy (SFA) among adults in Vietnam. We investigated the characteristics of individuals with SFA and the risk factors for severe SFA.

Patients and methods

A cross-sectional, web-based survey was conducted among individuals aged ≥ 18 years from universities in Ho Chi Minh City (Vietnam) between December 2021 and July 2022. The survey was based on a structured, validated questionnaire related to FA. Strict definitions of "convincing allergy" were used. Multivariate analysis was used to estimate the risk factors for severe SFA after adjusting for covariates. Data were analyzed using JASP (v.0.16.3) and SPSS (v.22.0).

Results

Totally, 1038 out of 2137 (48.57%) individuals completed the questionnaire, of whom 285 (27.46%) had reported SFA. Convincing SFA accounted for 20.13% (209/1038) of the cases, with convincing shellfish allergy being more common than fish allergy. Participants with comorbid shellfish and fish allergy had higher prevalence of atopic dermatitis, peanut/nut allergy, other food allergy, and cutaneous and upper airway symptoms compared to participants with shellfish allergy (p < 0.05). The spectrum of reactive seafood was diverse and characterized by local species. The age of symptom onset was most commonly during late childhood and adolescence, with most reactions persisting into adulthood. A history of anaphylaxis, comorbid peanut, and tree nut allergy, and ≥3 allergens were associated with severe SFA.

Conclusion

Features of causative, coexisting seafood allergy, and risk factors for severe SFA were demonstrated, which can provide a reference for future studies.

Reducing the allergenicity of tropomyosin in shrimp by covalent conjugation with quercetin and chlorogenic acid

The study aimed to assay the allergenicity of shrimp tropomyosin (TM) following covalent conjugation with quercetin (QR) and chlorogenic acid (CA). The structure of the TM-polyphenol covalent conjugates was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), circular dichroism (CD), fluorescence, differential scanning calorimetry (DSC), and Fourier Transform infrared spectroscopy (FTIR). Potential allergenicity was evaluated using in vitro and in vivo methods. The results showed that QR and CA induced structural changes in TM through aggregation. RBL-2H3 cell results showed that TM-QR and TM-CA covalent conjugates reduced the release of β-hexosaminidase and histamine, respectively. In the mice model, TM-QR and TM-CA covalent conjugates reduced the level of IgE, IgG, IgG1, histamine, and mMCP-1 in sera. Furthermore, the allergenicity was reduced by suppressing Th2-related cytokines (IL-4, IL-5, IL-13) and promoting Th1-related cytokines (IFN-γ). These research findings demonstrate that the covalent binding of TM with QR and CA, modifies the allergenic epitopes of shrimp TM, thereby reducing its potential allergenicity. This approach holds practical applications in the production of low-allergenicity food within the food industry.

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.

Dietary Intervention during Weaning and Development of Food Allergy: What Is the State of the Art?

Food allergy (FA) affects approximately 6-8% of children worldwide causing a significant impact on the quality of life of children and their families. In past years, the possible role of weaning in the development of FA has been studied. According to recent studies, this is still controversial and influenced by several factors, such as the type of food, the age at food introduction and family history. In this narrative review, we aimed to collect the most recent evidence about weaning and its role in FA development, organizing the gathered data based on both the type of study and the food. As shown in most of the studies included in this review, early food introduction did not show a potential protective role against FA development, and we conclude that further evidence is needed from future clinical trials.

Climate Change and Food Allergy

The role of environmental factors including climate change and consequent influences of air pollution on food allergy remains less explored compared with impacts on allergic rhinitis and asthma. In this review, we discuss the epithelial barrier hypothesis as a proposed mechanism of food allergy development that may be relevant in this context. We also discuss existing studies that provide insight into the intricate relationship between food allergy and climate-related environmental factors.

Evaluation of vitamin B12 values at time of diagnosis in 0- to 36-month-old children with food allergies

OBJECTIVES

The relationship between food allergies and vitamin B12 deficiency in young children remains unclear despite extensive studies on the nutritional status of affected children. The aim of this study was to compare vitamin B12 levels in children with recently diagnosed food allergies and healthy children ages 0 to 36 mo.

METHODS

A retrospective study at Başkent University Hospital analyzed 773 patients ages 0 to 36 mo. Participants were divided into two groups: food allergy and healthy. Vitamin B12 deficiency (<300 ng/mL) was assessed using χ2 tests and regression analyses.

RESULTS

The sample comprised 773 children ages 0 to 36 mo, with a mean age of 16 ± 9 mo (range: 1-36). Among the participants, 399 (52%) were healthy children, whereas 374 (48%) had food allergies. The prevalence of vitamin B12 deficiency was higher in children with food allergies (38%) than in healthy children (21%; P < 0.001). According to both univariate and multivariate regression analyses, formula feeding showed a negative association with vitamin B12 deficiency (β = -0.54; 95% confidence interval [CI], 0.35-0.97; P = 0.038). On the other hand, having allergic diseases (β = 0.69; 95% CI, 0.30-0.83; P = 0.040) and breastfeeding for <6 mo (β = 1.35; 95% CI, 1.41-10.50-0.50; P = 0.009) exhibited a positive association with vitamin B12 deficiency.

CONCLUSION

Food-allergic children ages 0 to 36 mo were at higher risk for vitamin B12 deficiency. Formula feeding had a protective effect, whereas allergic diseases and breastfeeding for <6 mo were risk factors. Further investigation is needed to understand the underlying mechanisms. Monitoring B12 levels and interventions are crucial for the nutritional well-being of food-allergic children.

How to handle off-label prescriptions of rupatadine, a second-generation antihistamine and PAF antagonist: a review

The off-label use of second-generation antihistamines, used outside of the formal indications authorized by regulatory authorities, in different age groups, doses or in special populations, is very common for many allergic, autoimmune and dermatological diseases. The off-label use of rupatadine (a second-generation antihistamine with PAF antagonist activity) in these conditions is reviewed here, including in combination with immunotherapy in the treatment of food allergy or allergic rhinitis, at high doses in chronic urticaria, and with prescriptions of less common but challenging conditions such as skin pruritus or mast cell activation disorders like mastocytosis. Rupatadine use is reviewed herein to confirm if its off-label management is supported by well-designed clinical trials or by published real-world cases. This review will contribute to increasing compliance and achieving better results in clinical practice. Off-label use of rupatadine should be left to the discretion of the prescribing healthcare professional after careful clinical evaluation.

Feeding Characteristics in Children With Food Allergies: A Scoping Review

BACKGROUND

Food allergy (FA) affects approximately 8% of children and may be immunoglobulin E (IgE)-mediated or non-IgE-mediated. It is recognized clinically that children with both subtypes of FA may present with features of pediatric feeding disorder (PFD); however, there is currently a limited detail of presenting characteristics.

OBJECTIVE

The objective of this study was to synthesize the current evidence regarding the feeding characteristics of children with FA, with a focus on the feeding skills and psychosocial domains of PFD.

METHOD

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. Papers published between 2001 and 2022 describing feeding characteristics in the feeding skills and psychosocial domains in children with FA/history of FA were included. Papers that focused solely on characteristics from the medical or nutritional domains were excluded. Descriptive information regarding demographics, methodology, allergy profile and history, and the characteristics of PFD observed was extracted using a preconceived data extraction form.

RESULTS

Overall, 40 papers contained descriptions of feeding characteristics of children with non-IgE-mediated FA (n = 22) and IgE-mediated FA (n = 11), while four were nonspecific. In the psychosocial domain, food refusal/aversion, anxiety with eating, and poor intake were the most frequently reported, regardless of FA subtype. Less information was reported regarding feeding skills, although slowness in eating, immature diet, and delays in oral sensory-motor skills were described.

CONCLUSIONS

Children with FA/history of FA may present with a range of characteristics that map across the feeding skill and psychosocial domains of PFD. Systematic research is needed to fully describe the feeding characteristics of children with FA.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24562732.

[Treatment for living with food allergy]

The treatment of food allergy involves completely removing the allergenic food from the diet, careful label reading, and ingredient awareness. Family education is crucial, understanding alternative names for the allergen. An emergency action plan provided by the doctor, with clear instructions for epinephrine application and when to seek medical attention, is essential. For mild to moderate symptoms, oral antihistamines may be prescribed. Psychological support is necessary due to emotional repercussions. Collaboration with an allergy specialist is crucial for personalized treatment. Natural tolerance to the food may be achieved, especially in non-IgE-mediated allergies. However, some allergic manifestations persist, requiring treatment alternatives. Avoidance of the allergen and epinephrine application are key measures. Immunotherapy aims to desensitize immune cells, but its effectiveness varies. Bioterapeutic agents, such as monoclonal antibodies, are under investigation, although their clinical use still requires more studies.

[Epidemiology of food allergy]

Food allergy is very common throughout the world and has become a major public health problem, with 220 million people suffering from it. Food allergy has been disproportionately observed in people from industrialized or Western countries and was previously considered to predominate in the pediatric versus adult population. However, the current exponential growth of the adult population and older adults, especially in Western countries, and environmental and lifestyle changes, have profoundly changed the epidemiology of food allergy, with a growing increase even at advanced ages. The foods that represent the greatest severity and clinical impact are peanuts, walnuts, fish, shellfish, eggs, cow's milk protein, wheat, soy and seeds. Although some types of food allergies (cow's milk and egg) may disappear, peanut and tree nut allergies may persist into adulthood. The control or cure of cow's milk protein allergy is gradual throughout childhood and adolescence. Despite the predominance of allergy to fish, shellfish, peanuts, and tree nuts in most reactions in adults, the most common form of IgE-mediated food allergy is oral allergy syndrome or pollen allergy syndrome. food.

[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.

Food allergy spectrum in the tropic: clinical and epidemiological profiles in a colombian hospital. A cross-sectional study

Introduction

Food allergy affects 2-10% of the general population; it is more frequent among children than among adults, and it is one of the leading causes of anaphylaxis. Diagnosis of food allergy requires a detailed medical history, skin tests, specific immunoglobulin E (IgE) tests for the food involved, and an oral challenge as final confirmation.

Objectives

This study aimed to describe the clinical and epidemiological characteristics of patients who underwent oral food challenges for suspected food allergies in a reference center in Colombia.

Methodology

An observational, descriptive, cross-sectional and retrospective study was conducted. Data were retrospectively collected from patients who were evaluated in the allergology service and suspected of food allergy from 2011 to 2018. Quantitative variables are presented as means or medians depending on the normality of the distribution (assessed by the Shapiro-Wilk test), and categorical variables are presented as frequencies and percentages.

Results

A total of 215 controlled open challenges were performed on 176 patients, most of whom were children (69%). Thirty-one patients (17%) required another oral challenge with a second food, and 11 (6.25%) required another oral challenge with three foods. Twelve oral challenges (5.58%) were positive. Of these, five challenges were positive for cow's milk, 5 were positive for shrimp, and 2 were positive for legumes (peanuts and lentils).

Conclusion

The frequency of confirmed food allergies and the profile of food allergies in our population differs from that reported in other parts of the world.

2'-Fucosyllactose alleviates OVA-induced food allergy in mice by ameliorating intestinal microecology and regulating the imbalance of Th2/Th1 proportion

Food allergy (FA) has become a prominent problem in public health. 2'-Fucosyllactose (2'-FL) was reported to alleviate FA symptoms; however, the regulatory mechanism is still unclear. This study evaluated the 2'-FL antiallergic potential in an ovalbumin (OVA)-sensitized mouse model and explored the systemic effects of 2'-FL on gut microecology and the intestinal immune barrier. The results showed that 2'-FL alleviated allergy symptoms, decreased serum allergic indicator levels, enhanced the intestinal barrier, and attenuated low-grade inflammation. The up-regulation of G protein-coupled receptors (GPRs) was associated with higher levels of short-chain fatty acids (SCFAs) in 2'-FL intervention mice. 2'-FL also improved the intestinal microbiota diversity and increased the abundance of Akkermansia, Lachnospiraceae UCG-006, and Ruminococcaceae while suppressing Muribaculaceae, Desulfovibrionaceae, and Erysipelotrichaceae. Additionally, 2'-FL ameliorated the imbalance of Th2/Th1, mainly by decreasing Th2-type immune response and enhanced CD4 + Foxp3 + Treg immunoreaction. These results suggest that 2'-FL restores intestinal barrier defects, gut microbiota disorder, and immune impairment while alleviating ovalbumin-induced allergic symptoms in FA mice.

Differential diagnostics of food allergy as based on provocation tests and laboratory diagnostic assays

Due to the scale of the phenomenon, food allergy constitute a significant health problem and significantly impair the quality of life of patients. Differential diagnostics, including skin tests, sIgE detection tests, basophil and mast cell activation tests as well as double-blind placebo-controlled food challenge tests, is the gold standard in the diagnosis of food allergy. Recently, increasing attention has been paid to the potential use of nasal provocation test in the diagnosis of food allergy. Allergen dose, protocol standardization, assessment of subjective complaints and objectivization of test results are important factors determining the applicability of provocation tests.

A multicenter analysis on the changes of sIgE in China during the early period of COVID-19 pandemic

OBJECTIVE

This study aims to analyze the changes in allergen composition ratio during the early stages of the COVID-19 outbreak in China and analyze the underlying factors contributing to these alterations.

METHODS

A multicenter study approach was employed. A total of 618 male and female patients (0-89 years old) were recruited from the dermatology, pediatrics, and allergy departments of 17 hospitals across 15 Chinese cities between January 2020 and June 2021. Serum samples were collected and subjected to allergen-specific immunoglobulin E (sIgE) detection using the reversed enzyme allegro-sorbent test. The allergens included Dermatophagoides pteronyssinus (D. pteronyssinus), Dermatophagoides farina (D. farina), Ambrosia artemisiifolia (A. artemisiifolia), Salix babylonica (S. babylonica), dog dander, alternaria, cockroach, Artemisia argyi (A. argyi), cat dander, house dust, milk, hen's egg, mutton, cod, peanut, beef, soybean, shrimp, crab, and wheat. Each participant was required to exhibit at least one positive sIgE detection result (≥0.35 IU/mL). The chi-square test was used to analyze the differences between groups.

RESULTS

The positive sIgE proportion of inhalation allergens were significantly lower than that of ingestion allergens. As restrictions on outdoor activities and seafood imports persisted, the positive sIgE proportion of wheat and shrimp exhibited a significant decrease in the spring of 2021 compared to the corresponding period in 2020. Conversely, there was a substantial increase in the positive proportion of crab. The fluctuation in the ratio of D. pteronyssinus and D. farina appeared to be influenced more by seasonal factors rather than the COVID-19 pandemic. However, no noteworthy disparities were observed in the proportions of other allergens.

CONCLUSION

The alterations in allergen composition during the initial phase of the epidemic may be attributed to several factors, such as decreased travel, increased mask usage, reduced carbohydrate consumption, and changes in seafood consumption. However, factors such as season, cultural practices, and customs may also influence the composition of allergens.

Allergen Stability in Food Allergy: A Clinician's Perspective

PURPOSE OF REVIEW

The globally rising food allergy prevalence is associated with the urgent need for new disease prevention methods, efficient treatment, and reliable risk assessment methods for characterization of food allergens. Due to inter-individual variations in the digestive system, food allergens are degraded to a different extent in each person. Food processing also influences allergen digestion.

RECENT FINDINGS

In this review, we provide an overview of the digestive system with focus on relevance for food allergy. Main food proteins causing allergic reactions are evaluated, and the combined role of food processing and digestion for allergen stability is highlighted. Finally, clinical implications of this knowledge are discussed. Recent literature shows that allergen digestibility is dependent on food processing, digestive conditions, and food matrix. Digestion affects proteins allergenicity. It is currently not possible to predict the immunogenicity of allergens solely based on protein stability.

A mouse model of food allergy permitting skin and nasal symptoms

PURPOSE

Developing experimental animal models that show clinical symptoms and methods for quantitative and objective evaluation are important for understanding food allergies. Therefore, this study aimed to develop an ovalbumin (OVA)-induced mouse model of food allergy and a useful method to evaluate the symptoms of food allergy.

MATERIAL/METHODS

Mice were sensitized via intraperitoneal injection of OVA. Subsequently, local sensitization was performed once weekly by oral administration of OVA. Itching and nasal symptoms were observed after oral administration of the antigen. First, we examined the dose-dependency of the antigen. Symptoms were checked weekly. In order to confirm food allergy symptoms, the effect of histamine H1 receptor antagonist was examined. Finally, we measured antigen-specific IgE antibody levels in the serum.

RESULTS

Scratching behavior, sneezing and nasal rubbing were increased. Both itching and rhinitis symptoms increased steadily, after which, the number of symptoms remained almost constant. No difference was observed between the results of 3- and 5-week-old mice. Cetirizine inhibited these symptoms in a dose-dependent manner. In addition, antigen-specific IgE antibodies were produced in both 3- and 5-week-old mice.

CONCLUSIONS

This method may be useful for evaluating the symptoms of skin and rhinitis that could not be assessed in the conventional food allergy model and could be induced with a low dose of antigen. In particular, the developed method, which measures the number of itching and nasal symptoms, may enable quantitative, objective, and noninvasive evaluation of food allergy severity.

Obesity and Selected Allergic and Immunological Diseases-Etiopathogenesis, Course and Management

Obesity is a global problem. It affects every age group and is associated with many negative health effects. As an example, there is a relationship between obesity and allergic and immunological diseases, such as asthma, psoriasis, food allergies, allergic rhinitis and atopic dermatitis. Obesity undeniably affects their development. In addition, it causes adverse changes in the course and response to therapy in relation to patients without excessive body weight. The treatment of diseases associated with obesity is difficult; drugs are less effective and must be used in higher doses, and their use in patients with obesity is often associated with higher risks. The main form of treatment of all obesity-related diseases is a change in eating habits and increased physical activity, which leads to a decrease in body fat mass. The positive effect of reducing BMI has been confirmed in many independent studies. This paper reviews various types of research documents published since 2019. It aims to systematize the latest knowledge and highlight the need for further research for effective and sustainable treatment options for obesity, its complications and obesity-related diseases.

Update on In Vitro Diagnostic Tools and Treatments for Food Allergies

Food allergy (FA) is an adverse immunological reaction to a specific food that can trigger a wide range of symptoms from mild to life-threatening. This adverse reaction is caused by different immunological mechanisms, such as IgE-mediated, non-IgE-mediated and mixed IgE-mediated reactions. Its epidemiology has had a significant increase in the last decade, more so in developed countries. It is estimated that approximately 2 to 10% of the world's population has FA and this number appears to be increasing and also affecting more children. The diagnosis can be complex and requires the combination of different tests to establish an accurate diagnosis. However, the treatment of FA is based on avoiding the intake of the specific allergenic food, thus being very difficult at times and also controlling the symptoms in case of accidental exposure. Currently, there are other immunomodulatory treatments such as specific allergen immunotherapy or more innovative treatments that can induce a tolerance response. It is important to mention that research in this field is ongoing and clinical trials are underway to assess the safety and efficacy of these different immunotherapy approaches, new treatment pathways are being used to target and promote the tolerance response. In this review, we describe the new in vitro diagnostic tools and therapeutic treatments to show the latest advances in FA management. We conclude that although significant advances have been made to improve therapies and diagnostic tools for FA, there is an urgent need to standardize both so that, in their totality, they help to improve the management of FA.

Prevalence of Parent-Reported Food Allergy in a Mexican Pre-School Population

The magnitude and relevance of food allergies in the preschool population remain unknown in most regions of Mexico and Latin America. Thus, our aim was to estimate the parent-reported prevalence of food allergies in a Mexican preschool population and to characterize their clinical diagnosis and presentation. A cross-sectional survey was conducted in Culiacán City. A validated questionnaire was utilized. A total of 810 parents responded to the questionnaire (valid response rate, 40.7%). The estimated prevalence rates (95% CI) were: "physician-diagnosed Food Allergy (FA), ever" 5.30% (3.86-7.08); "immediate-type FA, ever" 2.96% (1.91-4.38); "immediate-type FA, current" 1.60% (0.86-2.73); and food-dependent anaphylaxis 1.11% (0.51-2.01). The main food allergens were milk (0.49%), strawberries (0.37%), egg, and soy (0.25% each). Atopic diseases and a family history of allergies were significantly associated with immediate-type FA. Among "immediate-type FA, current" cases, 76.9% required emergency room visits, but the prescription of epinephrine autoinjectors was reported in one case only. The food reactions occurred at home (92.35%), in a relative's house (38.5), and at restaurants (23%). Immediate-type FA reactions requiring emergency room visits are not uncommon among the studied population. Actions like proper anaphylaxis management and the prevention of cross-contamination of foods should be encouraged.

Update on clinical research for food allergy treatment

The incidence of IgE-mediated food allergy (FA) has continued to increase over the years which places substantial burden on patient health and quality of life. With no cure for this disease, the mainstay of management has been allergen avoidance. However, there have been advancements in FA treatment in recent years with multiple clinical trials utilizing novel and innovative therapeutic strategies. A landmark event came in 2020 with the first drug approval for food allergy with the approval of a product for peanut oral immunotherapy. In addition to oral immunotherapy, different delivery systems of immunotherapy (SLIT, EPIT) are being studied in addition to probiotics, biologic agents - used as monotherapy and as an adjunct, and modified allergens has taken place with the hope to further enhance existing therapeutic options. The hope through these continued developments is for therapies to emerge that will provide a more comprehensive benefit to this patient population.

Effects of Insect Consumption on Human Health: A Systematic Review of Human Studies

Insects have been consumed as food in diverse cultures worldwide, gaining recognition as a sustainable and nutritious food source. This systematic review aims to update information on the impact of insect consumption on human health based on human randomized controlled trials (RCTs) and allergenicity assessment studies. Following PRISMA guidelines, studies published in the last 10 years were analyzed. From one-thousand and sixty-three retrieved references, nine RCTs and five allergenicity studies were analyzed. Post-prandial amino acid levels increased after insect protein consumption. In comparison with other protein sources, insect protein showed no significant differences in the area under the curve (AUC) values for essential amino acids but tended to have lower peaks and peak later. In terms of muscle protein synthesis, there were no significant differences between insect protein and other protein sources. Glucose levels did not differ; however, insulin levels were lower after the consumption of insect-based products. The effects on inflammatory markers and microbiota composition were inconclusive and the studies did not show significant effects on appetite regulation. Allergenicity assessments revealed a sensitisation and cross-reactivity between insect allergens and known allergens. A partial reduction of cross-allergenicity was observed via thermal processing. Insect protein is an adequate protein source with promising health benefits; however, further research is needed to fully understand its potential and optimise its inclusion into the human diet.

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.

Intermittent fasting protects against food allergy in a murine model via regulating gut microbiota

Background

The prevalence of food allergy (FA) is increasing. Decreases in the diversity of gut microbiota may contribute to the pathogenesis of FA by regulating IgE production of B cells. Intermittent fasting (IF) is a popular diet with the potential to regulate glucose metabolism, boosting immune memory and optimizing gut microbiota. The potential effect of long-term IF on the prevention and treatment of FA is still unknown.

Methods

Two IF protocols (16 h fasting/8 h feeding and 24 h fasting/24 h feeding) were conducted on mice for 56 days, while the control mice were free to intake food (free diet group, FrD). To construct the FA model, all mice were sensitized and intragastrical challenged with ovalbumin (OVA) during the second half of IF (day 28 to day 56). Rectal temperature reduction and diarrhea were recorded to evaluate the symptoms of FA. Levels of serum IgE, IgG1, Th1/Th2 cytokines, mRNA expression of spleen T cell related transcriptional factors, and cytokines were examined. H&E, immunofluorescence, and toluidine blue staining were used to assess the structural changes of ileum villi. The composition and abundance of gut microbiota were analyzed by 16srRNA sequencing in cecum feces.

Results

The diarrhea score and rectal temperature reduction were lower in the two fasting groups compared to the FrD groups. Fasting was associated with lower levels of serum OVA-sIgE, OVA-sIgG1, interleukin (IL)-4 and IL-5, and mRNA expression of IL-4, IL-5, and IL-10 in the spleen. While no significant association was observed in interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-6, IL-2 levels. Less mast cell infiltration in ileum was observed in the 16h/8h fasting group compared to the FrD group. ZO-1 expression in the ileum of the two fasting groups was higher in IF mice. The 24h/24h fasting reshaped the gut microbiota, with a higher abundance of Alistipes and Rikenellaceae strains compared to the other groups.

Conclusion

In an OVA-induced mice FA model, long-term IF may attenuate FA by reducing Th2 inflammation, maintaining the integrity of the intestinal epithelial barrier, and preventing gut dysbiosis.

Parents' and Health Care Professionals' Perspectives on Prevention and Prediction of Food Allergies in Children: Protocol for a Qualitative Study

BACKGROUND

Food allergy in children is increasing in prevalence in the western world and appears to become an important health problem. Parents of children at risk of food allergy live with the fear of allergic reaction, especially when the children are very young. The paradigm shift in allergy prevention in the last decade-away from allergen avoidance toward a tolerance induction approach-challenges both parents and health care professionals, as they have to deal with changing information and new evidence that often contradicts previous assumptions. Yet, research on health information-seeking behavior and needs of parents on primary prevention of food allergy in children as well as on prediction and prevention strategies of German health care professionals is lacking.

OBJECTIVE

The aim of the study is to explore and understand parents' and health care professionals' perspectives on the prediction and prevention of food allergies. We are particularly interested in information needs, information seeking, and health care usage and place a special focus on families' experiences when their child is at risk or diagnosed with food allergies. Furthermore, food allergy prediction and prevention strategies of health care professionals will be explored.

METHODS

This study is part of the NAMIBIO (food allergy biomarker) app consortium, which aims to identify early predictors for the development of food allergy in children and develop apps to guide health care professionals and parents of children with a high risk of food allergy toward prevention and timely tolerance induction. The study uses a qualitative approach with topic-guided interviews and focus groups with parents of children (0-3 years) and health care professionals. Data collection will continue until theoretical saturation is reached. The qualitative content analysis will be used according to Kuckartz to identify overarching themes toward information needs and seeking behavior as well as usage of health care and health care professionals' predictive and preventive strategies. In addition, a constructivist grounded theory approach will be used to explore and understand parents' experiences, interactions, and social processes in families in daily life.

RESULTS

Recruitment and data collection started in February 2022 and is still ongoing.

CONCLUSIONS

The qualitative study will provide insight into parents' information-seeking behavior and needs regarding the prevention of food allergy in children, parents' use of pediatric primary care, and health care professionals strategies for the prediction and prevention of food allergies in children. We assume that our results will highlight the challenges associated with the paradigm shift in allergy prevention for both parents and health care professionals. The results will be used to make practical recommendations from the user's perspective and inform the development of the NAMIBIO apps.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/41436.

Efficacy and safety of food allergy oral immunotherapy in adults

BACKGROUND

Oral immunotherapy (OIT) is an emerging method for treating food allergy in children. However, data regarding adults undergoing this process are lacking.

METHODS

We retrospectively analyzed the medical records of patients with food allergy aged ≥17 years who completed OIT treatment between April 2010 and December 2020 at Shamir Medical Center. Data were compared with that of children aged 4 to <11 years and adolescents aged ≥11 to 17 treated during the same time period.

RESULTS

A total of 96 adults at a median age of 22.3 years who underwent OIT for milk (n = 53), peanut (n = 18), sesame (n = 7), egg (n = 5), and tree nuts (n = 13) were analyzed and compared with 1299 children and 309 adolescents. Adults experienced more adverse reactions requiring injectable epinephrine, both during in-clinic up-dosing (49% vs. 15.9% and 26.5% for children and adolescents, respectively, p < 0.0001) and during home treatment (22.9% vs. 12.4%, p = 0.007 for children, and 17.5%, p = 0.23 for adolescents). Most adults (61.5%) were fully desensitized, but the rates of full desensitization were significantly lower than children (73.4%, p = 0.013). Significantly more adults (28.3%) undergoing milk OIT failed treatment than children (14.3%, p = 0.015) and adolescents (14.1%, p = 0.022), while failure rates in adults undergoing OIT for other foods were low (9.3%) and comparable with children and adolescents.

CONCLUSIONS

OIT is successful in desensitizing most adults with IgE-mediated food allergy. Adults undergoing milk OIT are at increased risk for severe reactions and for OIT failure while failure rates in adults undergoing OIT for other foods are low.

Oral Immunotherapy

Oral immunotherapy (OIT) is an alternative treatment of IgE-mediated food allergy that has been shown to increase tolerance threshold to many of the top food allergens, although this effect may be dependent on age, dose, frequency, and duration. OIT has been shown to be effective and safe in infants, and early initiation can improve rates of desensitization even for those foods whose natural history favors loss of allergy. Studies looking at protocol modification to improve OIT success are ongoing as is the evaluation of clinical tools to help monitor OIT effects.

Food Allergy in Preschoolers: Parents' Perception and Self-Reported Prevalence

BACKGROUND

Food allergy is a potentially fatal condition (in the case of anaphylaxis, for example) and is characterized by an increasing prevalence. The main purpose of this study is to identify preschool children with parent-reported food allergies and characterize this population and type of allergy.

METHODS

This is a cross-sectional study, based on questionnaires to parents/legal guardians. All children who attend daycare or preschool in an area of the city of Porto, Portugal, were included.

RESULTS

A total of 740 questionnaires were distributed to nine schools, and responses were obtained from 363 (49.1%). Self-reported food reaction and/or allergy was related in 11.2% of children. The median age of the first reaction was 12 months and the most registered foods were milk, dry seed, and peanut. Cutaneous (48.7%) and gastrointestinal (35.9%) symptoms were the main manifestations. History of parents' and siblings' food allergies had statistically significant associations with food reactions and/or allergies of the child, with OR 3.05 (p=0.04, 95% CI 1.01-8.81) and OR 8.69 (p<0.01, 95% CI 2.11-35.79), respectively. Besides that, children's atopic dermatitis also had a statistically significant association with self-reported food reactions and/or allergies, with OR 2.30 (p<0.05, 95% CI 1.01-5.21).

CONCLUSION

Food reactions and/or allergies were reported in 11.2% of children. The history of parents' and siblings' food allergies and children's atopic dermatitis had statistically significant associations with food reactions and/or allergies, which shows that it may be an important factor to consider.

Management of Adult Patients with Gastrointestinal Symptoms from Food Hypersensitivity-Narrative Review

The incidence of food hypersensitivity has increased dramatically over the years not only among children but also in adults. Adult patients are usually less suspected of food hypersensitivity symptoms since food allergies are more typical for small children, with a tendency to outgrow the condition. The aim of this article is to increase awareness of hypersensitivity to food symptoms and their diagnosis and treatment possibilities among gastroenterologists and other health care professionals dealing with this type of patient. Symptoms of many gastrointestinal disorders, especially functional, may be driven by different types of mechanisms, and food intolerance or allergy should be considered as a potential cause. This article presents the current understanding of the epidemiology, diagnosis and treatment of immune- and non-immune-mediated food-induced diseases. Diagnosis of food hypersensitivity is based mainly on medical history, different types of sensitivity tests, e.g., hydrogen breath test, specific IgE (sIgE) serum concentration, tissue eosinophil count, skin tests and oral food challenges considered as a "gold standard" for food allergy. Elimination diet and pharmacologic treatment for allergy symptoms are first-line therapies. Eosinophilic gastrointestinal diseases are often caused by non-IgE-mediated food allergies, require endoscopic biopsy samples to confirm diagnosis and proper elimination diet often combined with steroids or proton pump inhibitor agents for treatment. Mast cell activation syndrome (MCAS) derives from pathologic reaction of mast cells with increased tryptase serum level as a marker. Symptoms may occur in the digestive, respiratory, skin, neurologic and cardiovascular system. Treatment is based on histamine type 1, type 2 (H1, H2) receptor antagonists and other mast cell stabilizing agents. Carbohydrate intolerances are the most common type of food hypersensitivity in adult patients, and an elimination diet is effective for reducing symptoms. Food additives hypersensitivity remains difficult to diagnose, but use of a diet low in chemical substances alleviates symptoms and helps to diagnose the triggering factors.

Perinatal exposure to foodborne inorganic nanoparticles: A role in the susceptibility to food allergy?

Food allergy (FA) is an inappropriate immune response against dietary antigens. Various environmental factors during perinatal life may alter the establishment of intestinal homeostasis, thereby predisposing individuals to the development of such immune-related diseases. Among these factors, recent studies have emphasized the chronic dietary exposure of the mother to foodborne inorganic nanoparticles (NP) such as nano-sized silicon dioxide (SiO₂), titanium dioxide (TiO₂) or silver (Ag). Indeed, there is growing evidence that these inorganic agents, used as food additives in various products, as processing aids during food manufacturing or in food contact materials, can cross the placental barrier and reach the developing fetus. Excretion in milk is also suggested, hence continuing to expose the neonate during a critical window of susceptibility. Due to their immunotoxical and biocidal properties, such exposure may disrupt the host-intestinal microbiota's beneficial exchanges and may interfere with intestinal barrier and gut-associated immune system development in fetuses then the neonates. The resulting dysregulated intestinal homeostasis in the infant may significantly impede the induction of oral tolerance, a crucial process of immune unresponsiveness to food antigens. The current review focuses on the possible impacts of perinatal exposure to foodborne NP during pregnancy and early life on the susceptibility to developing FA.

Predicting probability of tolerating discrete amounts of peanut protein in allergic children using epitope-specific IgE antibody profiling

BACKGROUND

IgE-epitope profiling can accurately diagnose clinical peanut allergy.

OBJECTIVE

We sought to determine whether sequential (linear) epitope-specific IgE (ses-IgE) profiling can provide probabilities of tolerating discrete doses of peanut protein in allergic subjects undergoing double-blind, placebo-controlled food challenges utilizing PRACTALL dosing.

METHODS

Sixty four ses-IgE antibodies were quantified in blood samples using a bead-based epitope assay. A pair of ses-IgEs that predicts Cumulative Tolerated Dose (CTD) was determined using regression in 75 subjects from the discovery cohort. This epitope-based predictor was validated on 331 subjects from five independent cohorts (ages 4-25 years). Subjects were grouped based on their predicted values and probabilities of reactions at each CTD threshold were calculated.

RESULTS

In discovery, an algorithm using two ses-IgE antibodies was correlated with CTDs (rho = 0.61, p < .05); this correlation was 0.51 (p < .05) in validation. Using the ses-IgE-based predictor, subjects were assigned into "high," "moderate," or "low" dose-reactivity groups. On average, subjects in the "high" group were four times more likely to tolerate a specific dose, compared with the "low" group. For example, predicted probabilities of tolerating 4, 14, 44, and 144 or 444 mg in the "low" group were 92%, 77%, 53%, 29%, and 10% compared with 98%, 95%, 94%, 88%, and 73% in the "high" group.

CONCLUSIONS

Accurate predictions of food challenge thresholds are complex due to factors including limited responder sample sizes at each dose and variations in study-specific challenge protocols. Despite these limitations, an epitope-based predictor was able to accurately identify CTDs and may provide a useful surrogate for peanut challenges.