Design of the Intervention to Reduce Early Peanut Allergy in Children (iREACH): A practice-based clinical trial

BACKGROUND

Introducing peanut products early can prevent peanut allergy (PA). The "Addendum guidelines for the prevention of PA in the United States" (PPA guidelines) recommend early introduction of peanut products to low and moderate risk infants and evaluation prior to starting peanut products for infants at high risk for PA (those with severe eczema and/or egg allergy). Rapid adoption of guidelines could aid in lowering the prevalence of PA. The Intervention to Reduce Early (Peanut) Allergy in Children (iREACH) trial was designed to promote PPA guideline adherence by pediatric clinicians.

METHODS

A two-arm, cluster-randomized, controlled clinical trial was designed to measure the effectiveness of an intervention that included clinician education and accompanying clinical decision support tools integrated in electronic health records (EHR) versus standard care. Randomization was at the practice level (n = 30). Primary aims evaluated over an 18-month trial period assess adherence to the PPA guidelines using EHR documentation at 4- and 6-month well-child care visits aided by natural language processing. A secondary aim will evaluate the effectiveness in decreasing the incidence of PA by age 2.5 years using EHR documentation and caregiver surveys. The unit of observation for evaluations are individual children with clustering at the practice level.

CONCLUSION

Application of this intervention has the potential to inform the development of strategies to speed implementation of PPA guidelines.

Development of an innovative curriculum for paediatricians on peanut allergy prevention: How do we address current guidelines?

BACKGROUND

There exists strong evidence for the early introduction of peanut to at-risk infants for the primary prevention of peanut allergy. There is a need for educational initiatives to assist in dissemination and implementation of updated clinical guidelines on peanut allergy prevention.

APPROACH

The aim for this project was to create an innovative curriculum for paediatricians on peanut allergy prevention. The Intervention to Reduce Early Allergy (Peanut) in Childhood (iREACH) study was leveraged to recruit paediatricians for a needs assessment. Materials from the iREACH study, including an educational YouTube video and knowledge survey, were evaluated. Applying findings from the needs assessment, an innovative curriculum was developed, and updated knowledge survey questions were developed.

EVALUATION

The iREACH YouTube video had suboptimal viewing behaviours, and iREACH participants had high baseline knowledge scores that did improve after viewing the video. The majority of respondents to the needs assessment felt that all paediatricians needed access to an effective educational module on peanut allergy prevention, and they wanted a broadly accessible curriculum that incorporated quality media and content segmentation. An online, interactive curriculum was developed that includes clinical cases and games, and updated knowledge questions were created with associated internal structure and reliability evidence, as well as relation to other variables evidence.

IMPLICATION

The next steps of this project will focus on curriculum implementation and evaluation through a randomised, prospective study with the aim to serve as an educational model for how to integrate specialty-specific guidelines into broader clinical practice through education.

Screening of probiotic Lactobacillus to reduce peanut allergy and with potential anti-allergic activity

BACKGROUND

Peanut is a significant source of nutrition and a valuable oilseed crop. It is also a serious allergy source, which poses a threat to 1.1% of the population. This study aimed to screen lactic acid bacteria (LAB) with the capacity to alleviate peanut allergenicity and exhibit anti-allergic properties.

RESULT

The results show that LAB can make use of substances in peanuts to reduce the pH of peanut milk from 6.603 to 3.593-4.500 by acid production and that it can utilize the protein in peanuts to reduce the allergenic content (especially Ara h 1) and improve biological activity in peanut pulp. The content of Ara h 1 peanut-sensitizing protein was reduced by 74.65% after fermentation. The protein extracted from fermented peanut pulp is more readily digestible by gastrointestinal juices. The inhibitory activity assay of hyaluronidase (an enzyme with strong correlation to allergy) increased from 46.65% to a maximum of 90.57% to reveal that LAB fermentation of peanut pulp exhibited a robust anti-allergic response.

CONCLUSION

The strains identified in this study exhibited the ability to mitigate peanut allergenicity partially and to possess potential anti-allergic properties. Lactobacillus plantarum P1 and Lactobacillus salivarius C24 were identified as the most promising strains and were selected for further research. © 2023 Society of Chemical Industry.

Optimising the management of peanut allergy by targeting immune plasticity

Randomised controlled trials investigating the efficacy of oral tolerance induction to peanut have enabled detailed comparison of their clinical and immunological success. They have demonstrated that the regular consumption of peanut for at least 2 years by babies who are not allergic enables protection from developing peanut allergy. The LEAP study intervention tested the impact of regular peanut consumption for 4 years and demonstrated a sustained protection against the development of peanut allergy even after 12 months of peanut avoidance from 5 to 6 years of age. The PreventADALL trial introduced multiple allergens into babies' diets from early infancy and reduced the prevalence of food allergy at 3 years, especially by protecting against peanut allergy. Immunological studies from the LEAP cohort demonstrated that regular peanut consumption was associated with a prompt induction of peanut-specific IgG4 and reduced manufacture of peanut and Ara h 2-specific IgE. Even after stopping peanut consumption for 5 years, there continued to be a significant fall in peanut-specific Ara h 2 IgE in the consumption group from 5 to 6 years of age (p < .01). Children who developed peanut allergy by 5 years started to develop increasing sensitisation to linear sequential peanut epitopes from 2.5 years of age, suggesting that putative disease-modifying interventions should commence before 3 years. Data comparing clinical outcomes between children undergoing peanut immunotherapy from infancy suggest that younger children can consume higher portions of peanut without reaction on challenge whilst taking immunotherapy, have fewer side effects and are more likely to enjoy remission of PA. Peanut oral immunotherapy modulates T-cell populations in order to bring about hypo-responsiveness of allergy effector cells. Studies are now needed to characterise and compare different states of immunological tolerance. This will accelerate the design of interventions which can promote primary, secondary and tertiary levels of PA prevention across a range of age groups.

Rates of New Peanut Allergy and Discontinuation Following Introduction in High-Risk Infants

BACKGROUND

Peanut introduction guidelines recommend that infants with severe eczema and/or egg allergy consume 6 g of peanut protein weekly to prevent peanut allergy. Rates of new peanut allergy after introduction and adherence remain under study.

OBJECTIVE

To determine compliance with peanut introduction guidelines, rates of new peanut allergy, and reasons for discontinuation of peanut consumption in a cohort of high-risk infants.

METHODS

A prospective cohort of 4- to 11-month-old high-risk infants (defined as moderate-severe eczema or non-peanut food allergy or a first-degree relative with peanut allergy) with no prior peanut exposure who were determined to not be peanut allergic were recommended to introduce 6 g of peanut protein weekly. Participants were followed to 30 months with 2 in-person visits and monthly questionnaires.

RESULTS

Two hundred seventy-seven infants were followed. At last follow-up, 245 (88%) were consuming some peanut protein with median weekly consumption of 3 g (interquartile range: 1-5 g). New peanut allergy developed in 6 (2%), with 2 of those cases consistent with food protein-induced enterocolitis syndrome. Fear of reaction in another household member was the most common reason for peanut discontinuation. Reactions to peanut after introduction in the index infant occurred in <2% of peanut-allergic siblings and in 20% of peanut-allergic parents.

CONCLUSION

We found low rates of new peanut allergy and generally low rates of peanut discontinuation after introduction in our high-risk cohort. However, families of high-risk infants require significant support with introduction, especially those with another peanut-allergic member.

Risk subgroups and intervention effects among infants at high risk for peanut allergy: A model for clinical decision making

BACKGROUND

The Learning Early About Peanut Allergy (LEAP) trial showed that early dietary introduction of peanut reduced the risk of developing peanut allergy by age 60 months in infants at high risk for peanut allergy. In this secondary analysis of LEAP data, we aimed to determine risk subgroups within these infants and estimate their respective intervention effects of early peanut introduction.

METHODS

LEAP raw data were retrieved from ITNTrialShare.org. Conditional random forest was applied to participants in the peanut avoidance arm to select statistically important features for the classification and regression tree (CART) analysis to group infants based on their risk of peanut allergy at 60 months of age. Intervention effects were estimated for each derived risk subgroup using data from both arms. Our main model was generated based on baseline data when the participants were 4-11 months old. Specific IgE measurements were truncated to account for the limit of detection commonly used by laboratories in clinical practice.

RESULTS

The model found infants with higher predicted probability of peanut allergy at 60 months of age had a similar relative risk reduction, but a greater absolute risk reduction in peanut allergy with early introduction of peanut, than those with lower probability. The intervention effects were significant across all risk subgroups. Participants with baseline peanut sIgE ≥0.22 kU/L (n = 78) had an absolute risk reduction of 40.4% (95% CI 27.3, 51.9) whereas participants with baseline peanut sIgE<0.22 kU/L and baseline Ara h 2 sIgE <0.10 kU/L (n = 226) had an absolute risk reduction of 6.5% (95% CI 2.6, 11.0). These findings were consistent in sensitivity analyses using alternative models.

CONCLUSION

In this study, risk subgroups were determined among infants from the LEAP trial based on the probability of developing peanut allergy and the intervention effects of early peanut introduction were estimated. This may be relevant for further risk assessment and personalized clinical decision-making.

Food allergies: Updates for nurses

ABSTRACT

Food allergies are on the rise; the incidence and types of foods implicated have increased worldwide. While peanut allergies are the most well-known, allergies exist to almost all types of foods. This article discusses various types of food allergies along with the most recent prevention and treatment strategies.

Reaching Communities Through Food Allergy Advocacy, Research, and Education: A Comprehensive Analysis

This article explores the multifaceted approach of food allergy (FA) advocacy, research, and education to address the diverse challenges associated with FA, such as disparities in socioeconomic status, food security, quality of life, and the overall burden of the disease. Advocacy initiatives are instrumental in driving policy changes, raising public awareness, and directing substantial research funding, with a focus on reducing disparities. They have influenced allergen labeling regulations and improved access to epinephrine, emphasizing the importance of school-based management plans, especially in underserved communities. Research in FA informs medical practices and offers them hope for improved treatments. Recent breakthroughs in peanut allergy prevention and oral immunotherapy trials exemplify the potential for advancements while highlighting the need to address disparities in health care access. Education is a critical tool for prevention, raising awareness, and reducing the risk of allergic reactions. Efforts should be tailored to reach marginalized communities, particularly in schools where education on FA management is essential. Collaborating directly with communities is imperative to ensure inclusivity and address disparities. Barriers such as mistrust, language and cultural differences, and lack of diversity among researchers must be overcome to encourage diverse participation in research studies. This article concludes by emphasizing the significance of a comprehensive approach to FA research that prioritizes equity and inclusivity. The call to action highlights the need for global initiatives to reshape the landscape of FA care and address disparities in health care access and outcomes.

Influence of antigen density and TLR ligands on preclinical efficacy of a VLP-based vaccine against peanut allergy

BACKGROUND

Virus-like particle (VLP) Peanut is a novel immunotherapeutic vaccine candidate for the treatment of peanut allergy. The active pharmaceutical ingredient represents cucumber mosaic VLPs (CuMVTT -VLPs) that are genetically fused with one of the major peanut allergens, Ara h 2 (CuMVTT -Ara h 2). We previously demonstrated the immunogenicity and the protective capacity of VLP Peanut-based immunization in a murine model for peanut allergy. Moreover, a Phase I clinical trial has been initiated using VLP Peanut material manufactured following a GMP-compliant manufacturing process. Key product characterization studies were undertaken here to understand the role and contribution of critical quality attributes that translate as predictive markers of immunogenicity and protective efficacy for clinical vaccine development.

METHOD

The role of prokaryotic RNA encapsulated within VLP Peanut on vaccine immunogenicity was assessed by producing a VLP Peanut batch with a reduced RNA content (VLP Peanut low RNA). Immunogenicity and peanut allergen challenge studies were conducted with VLP Peanut low RNA, as well as with VLP Peanut in WT and TLR 7 KO mice. Furthermore, mass spectrometry and SDS-PAGE based methods were used to determine Ara h 2 antigen density on the surface of VLP Peanut particles. This methodology was subsequently applied to investigate the relationship between Ara h 2 antigen density and immunogenicity of VLP Peanut.

RESULTS

A TLR 7 dependent formation of Ara h 2 specific high-avidity IgG antibodies, as well as a TLR 7 dependent change in the dominant IgG subclass, was observed following VLP Peanut vaccination, while total allergen-specific IgG remained relatively unaffected. Consistently, a missing TLR 7 signal caused only a weak decrease in allergen tolerability after vaccination. In contrast, a reduced RNA content for VLP Peanut resulted in diminished total Ara h 2 specific IgG responses, followed by a significant impairment in peanut allergen tolerability. The discrepant effect on allergen tolerance caused by an absent TLR 7 signal versus a reduced RNA content is explained by the observation that VLP Peanut-derived RNA not only stimulates TLR 7 but also TLR 3. Additionally, a strong correlation was observed between the number of Ara h 2 antigens displayed on the surface of VLP Peanut particles and the vaccine's immunogenicity and protective capacity.

CONCLUSIONS

Our findings demonstrate that prokaryotic RNA encapsulated within VLP Peanut, including antigen density of Ara h 2 on viral particles, are key contributors to the immunogenicity and protective capacity of the vaccine. Thus, antigenicity and RNA content are two critical quality attributes that need to be determined at the stage of manufacturing, providing robust information regarding the immunogenicity and protective capacity of VLP Peanut in the mouse which has translational relevance to the human setting.

Oral Immunotherapy for Peanut Allergy in Children 1 to Less Than 4 Years of Age

Oral Immunotherapy for Peanut Allergy in ChildrenThis trial enrolled children 1 to <4 years of age who had allergic symptoms from peanut protein during screening. Participants received peanut allergen powder-dnfp (PTAH) or placebo for approximately 12 months; 73.5% of participants receiving PTAH tolerated a single dose of ≥600 mg peanut protein versus 6.3% of the placebo group.

Updates in Food Allergy Prevention in Children

Although significant evidence exists that feeding early has a role in the prevention of food allergy, this intervention in isolation may not be sufficient. Recent evidence highlights that early introduction of peanut specifically has had no significant impact on the populational prevalence of peanut allergy. Other factors that may contribute to food allergy prevention include regularity of ingestion once an allergen is introduced and consideration to the form in which the allergen is introduced (such as baked versus cooked egg). There are also many practicalities to early feeding and some discrepant viewpoints on these practicalities, which has led to poor implementation of early feeding strategies. In general, preemptive screening before food introduction is not recommended by most international allergy societies. Although there is little guidance to inform early introduction of allergens other than milk, egg, and peanut, the mechanism of sensitization is thought to be similar and there is no harm to early introduction. In terms of frequency and duration of feeding, there is little evidence to inform any concrete recommendations.

Early Peanut Immunotherapy in Children (EPIC) trial: protocol for a pragmatic randomised controlled trial of peanut oral immunotherapy in children under 5 years of age

INTRODUCTION

Food allergy is a major public health challenge in Australia. Despite widespread uptake of infant feeding and allergy prevention guidelines the incidence of peanut allergy in infants has not fallen, and prevalence of peanut allergy in school-aged children continues to rise. Therefore, effective and accessible treatments for peanut allergy are required. There is high-quality evidence for efficacy of oral immunotherapy in children aged 4-17 years old; however, few randomised trials have investigated peanut oral immunotherapy (OIT) in young children. Furthermore, the use of food products for OIT with doses prepared and administered by parents without requiring pharmacy compounding has the potential to reduce costs associated with the OIT product.

METHODS AND ANALYSIS

Early Peanut Immunotherapy in Children is an open-label randomised controlled trial of peanut OIT compared with standard care (avoidance) to induce desensitisation in children aged 1-4 years old with peanut allergy. n=50 participants will be randomised 1:1 to intervention (daily peanut OIT for 12 months) or control (peanut avoidance). The primary outcome is the proportion of children in each group with a peanut eliciting dose >600 mg peanut protein as assessed by open peanut challenge after 12 months, analysed by intention to treat. Secondary outcomes include safety as assessed by frequency and severity of treatment-related adverse events, quality of life measured using age-appropriate food allergy-specific questionnaires and immunological changes during OIT.

ETHICS

The trial is approved by the Child and Adolescent Health Service Human Research Ethics Committee and prospectively registered with the Australia and New Zealand Clinical Trials Registry.

DISSEMINATION

Trial outcomes will be published in a peer-review journal and presented and local and national scientific meetings.

TRIAL REGISTRATION NUMBER

ACTRN12621001001886.

Early Peanut Introduction in Infants: Improving Guideline Adherence With EMR Standardization

OBJECTIVES

Peanut allergy in children is a population health problem. Evidence suggests early peanut introduction (EPI) for infants can reduce the development of peanut allergy. Primary care settings have not widely adopted guidelines recommending EPI. Peanut allergy prevention depends on primary care providers incorporating EPI guidelines into well-child check (WCC) encounters. We aimed to improve guideline adherence in a primary care setting by implementing a bundle of clinical decision support (CDS) tools.

METHODS

Using quality improvement methodology, the team developed a standardized work protocol and CDS tools within an electronic medical record (EMR) at 4, 6, and 9-month WCC encounters. The team executed changes and modifications through plan-do-study-act cycles and analyzed results with statistical process control charts.

RESULTS

We collected data from 445 WCC encounters from baseline through sustainability. EMR documentation of EPI guidance at 4, 6, and 9-month WCCs shifted from 13.9% to 83.5% over 12 months. Provider adoption of smart lists and templates increased from 2% to 73%, the distribution of home peanut introduction handouts increased from 5.2% to 54.1%, and caregiver-reported peanut ingestion increased from 0% to 34.6%. Diphtheria-tetanus-acellular pertussis vaccination rates remained at 100% for 6-month visits, and patient in-room time remained at 65 minutes.

CONCLUSIONS

Quality improvement methodology improved documentation of EPI guidance and increased reported peanut ingestion at routine WCC encounters without impacting other measures. Broader use of bundled CDS tools and EMR standardization could further improve guideline adherence and increase early peanut introduction to prevent peanut allergy in infants.

A Survey of Canadian Dietitians on Identification of Infants at High Risk of Food Allergy and Frequency of Allergenic Food Consumption

Purpose: To assess knowledge of Canadian dietitians on the topics of food allergy and food allergy prevention guidelines, including introduction of allergenic solids to infants at risk of food allergy.Methods: An online survey was distributed via email listservs targeting Canadian dietitians.Results: In total, 144 of 261 dietitians completed the survey (60.5%). Respondents recommend introduction of peanut (89.5%) and allergenic solids (91.2%) within the recommended age of 4-6 months for infants at high risk of food allergy, but only 26.2% recommend offering peanut three times per week once it has been introduced. In identifying what constitutes an infant at high risk of developing peanut allergy, dietitians expressed lower comfort levels and lower number of correct responses.Conclusions: Dietitians demonstrated they are up to date regarding the timing of introduction of allergenic solids, but not the frequency of consumption once introduced, for infants at high risk of food allergy. They also expressed low comfort level identifying risk factors for peanut allergy. There are opportunities for further education of dietitians, as well as potential to further utilize dietitian services for the benefit of patients with food allergy or who are at risk for food allergy.

A phase II study of Bruton's tyrosine kinase inhibition for the prevention of anaphylaxis

BACKGROUNDIgE-mediated anaphylaxis is a potentially fatal systemic allergic reaction for which there are no currently FDA-approved preventative therapies. Bruton's tyrosine kinase (BTK) is an essential enzyme for IgE-mediated signaling pathways and is an ideal pharmacologic target to prevent allergic reactions. In this open-label trial, we evaluated the safety and efficacy of acalabrutinib, a BTK inhibitor that is FDA approved to treat some B cell malignancies, in preventing clinical reactivity to peanut in adults with peanut allergy.METHODSAfter undergoing graded oral peanut challenge to establish their baseline level of clinical reactivity, 10 patients had a 6-week rest period, then received 4 standard doses of 100 mg acalabrutinib twice daily and underwent repeat food challenge. The primary endpoint was the change in patients' threshold dose of peanut protein to elicit an objective clinical reaction.RESULTSAt baseline, patients tolerated a median of 29 mg of peanut protein before objective clinical reaction. During subsequent food challenge on acalabrutinib, patients' median tolerated dose significantly increased to 4,044 mg (range 444-4,044 mg). 7 patients tolerated the maximum protocol amount (4,044 mg) of peanut protein with no clinical reaction, and the other 3 patients' peanut tolerance increased between 32- and 217-fold. 3 patients experienced a total of 4 adverse events that were considered to be possibly related to acalabrutinib; all events were transient and nonserious.CONCLUSIONAcalabrutinib pretreatment achieved clinically relevant increases in patients' tolerance to their food allergen, thereby supporting the need for larger, placebo-controlled trials.TRIAL REGISTRATIONClinicalTrials.gov NCT05038904FUNDINGAstraZeneca Pharmaceuticals, the Johns Hopkins Institute for Clinical and Translational Research, the Ludwig Family Foundation, and NIH grants AI143965 and AI106043.

Environmental Exposure to Foods as a Risk Factor for Food Allergy

PURPOSE OF REVIEW

Many factors have been reported to contribute to the development of food allergy. Here, we summarize the role of environmental exposure to foods as a major risk factor for developing food allergy.

RECENT FINDINGS

Peanut proteins are detectable and biologically active in household environments, where infants spend a majority of their time, providing an environmental source of allergen exposure. Recent evidence from clinical studies and mouse models suggests both the airway and skin are routes of exposure that lead to peanut sensitization. Environmental exposure to peanut has been clearly associated with the development of peanut allergy, although other factors such as genetic predisposition, microbial exposures, and timing of oral feeding of allergens also likely contribute. Future studies should more comprehensively assess the contributions of each of these factors for a variety of food allergens to provide more clear targets for prevention of food allergy.

Food Allergies: Diagnosis, Treatment, and Prevention

In the United States, approximately 2% to 3% of adults and 8% of children have a food allergy. Allergic reactions range from minor pruritus to life-threatening anaphylaxis. These allergies often lead to significant anxiety and costs for patients and caregivers. Common food allergies include peanuts, cow's milk, shellfish, tree nuts, egg, fish, soy, and wheat. Peanut allergy, the most common, is the leading cause of life-threatening anaphylaxis. Children with asthma, allergic rhinitis, atopic dermatitis, or an allergy to insect venom, medications, or latex are at an increased risk of developing food allergies. Diagnosis of food allergy starts with a detailed, allergy-focused history. Serum immunoglobulin E and skin prick testing provide reliable information regarding food allergy diagnoses. Primary treatment involves elimination of the offending food from the diet. Prevention strategies proven to decrease the risk of developing a food allergy include restricting exposure to cow's milk in the first three days of life and early sequential exposure to allergenic foods starting between four and six months of age. Exclusive breastfeeding for three to four months reduces the likelihood of developing eczema and asthma but does not reduce development of food allergies. Most children eventually outgrow allergies to cow's milk, egg, soy, and wheat. However, allergies to tree nuts, peanuts, and shellfish are more likely to be lifelong.

Defining the window of opportunity and target populations to prevent peanut allergy

BACKGROUND

Peanut allergy affects 1% to 2% of European children. Early introduction of peanut into the diet reduces allergy in high-risk infants.

OBJECTIVE

We aimed to determine the optimal target populations and timing of introduction of peanut products to prevent peanut allergy in the general population.

METHODS

Data from the Enquiring About Tolerance (EAT; n = 1303; normal risk; 3-year follow-up; ISRCTN14254740) and Learning Early About Peanut Allergy study (LEAP; n = 640; high risk; 5-year follow-up; NCT00329784) randomized controlled trials plus the Peanut Allergy Sensitization (PAS; n = 194; low and very high risk; 5-year follow-up) observational study were used to model the intervention in a general population. Peanut allergy was defined by blinded peanut challenge or diagnostic skin prick test result.

RESULTS

Targeting only the highest-risk infants with severe eczema reduced the population disease burden by only 4.6%. Greatest reductions in peanut allergy were seen when the intervention was targeted only to the larger but lower-risk groups. A 77% reduction in peanut allergy was estimated when peanut was introduced to the diet of all infants, at 4 months with eczema, and at 6 months without eczema. The estimated reduction in peanut allergy diminished with every month of delayed introduction. If introduction was delayed to 12 months, peanut allergy was only reduced by 33%.

CONCLUSIONS

The preventive benefit of early introduction of peanut products into the diet decreases as age at introduction increases. In countries where peanut allergy is a public health concern, health care professionals should help parents introduce peanut products into their infants' diet at 4 to 6 months of life.

Allergenicity of peanut allergens and its dependence on the structure

Food allergies are a global food safety problem. Peanut allergies are common due, in part, to their popular utilization in the food industry. Peanut allergy is typically an immunoglobulin E-mediated reaction, and peanuts contain 17 allergens belonging to different families in peanut. In this review, we first introduce the mechanisms and management of peanut allergy, followed by the basic structures of associated allergens. Subsequently, we summarize methods of epitope localization for peanut allergens. These methods can be instrumental in speeding up the discovery of allergenicity-dependent structures. Many attempts have been made to decrease the allergenicity of peanuts. The structures of hypoallergens, which are manufactured during processing, were analyzed to strengthen the desensitization process and allergen immunotherapy. The identification of conformational epitopes is the bottleneck in both peanut and food allergies. Further, the identification and modification of such epitopes will lead to improved strategies for managing and preventing peanut allergy. Combining traditional wet chemistry research with structure simulation studies will help in the epitopes' localization.

Peanut allergen inhibition prevents anaphylaxis in a humanized mouse model

Peanut-induced allergy is an immunoglobulin E (IgE)-mediated type I hypersensitivity reaction that manifests symptoms ranging from local edema to life-threatening anaphylaxis. Although there are treatments for symptoms in patients with allergies resulting from allergen exposure, there are few preventive therapies other than strict dietary avoidance or oral immunotherapy, neither of which are successful in all patients. We have previously designed a covalent heterobivalent inhibitor (cHBI) that binds in an allergen-specific manner as a preventive for allergic reactions. Building on previous in vitro testing, here, we developed a humanized mouse model to test cHBI efficacy in vivo. Nonobese diabetic-severe combined immunodeficient γc-deficient mice expressing transgenes for human stem cell factor, granulocyte-macrophage colony-stimulating factor, and interleukin-3 developed mature functional human mast cells in multiple tissues and displayed robust anaphylactic reactions when passively sensitized with patient-derived IgE monoclonal antibodies specific for peanut Arachis hypogaea 2 (Ara h 2). The allergic response in humanized mice was IgE dose dependent and was mediated by human mast cells. Using this humanized mouse model, we showed that cHBI prevented allergic reactions for more than 2 weeks when administered before allergen exposure. cHBI also prevented fatal anaphylaxis and attenuated allergic reactions when administered shortly after the onset of symptoms. cHBI impaired mast cell degranulation in vivo in an allergen-specific manner. cHBI rescued the mice from lethal anaphylactic responses during oral Ara h 2 allergen-induced anaphylaxis. Together, these findings suggest that cHBI has the potential to be an effective preventative for peanut-specific allergic responses in patients.

The Case for Prompt Salvage Infant Peanut Oral Immunotherapy Following Failed Primary Prevention

Recent guideline recommendations have shifted from recommending prolonged avoidance of allergenic foods in the first 3 years of life to a primary prevention approach involving the deliberate early introduction to infants at risk of developing food allergy. Despite this, some infants, especially those with severe eczema who are at highest risk for developing peanut allergy, fail to receive the preventative benefits of early peanut introduction due to hesitancy and other factors. Difficulty adhering to regular ingestion after introduction further reduces the effectiveness of primary prevention. As emerging real-world evidence has demonstrated that performing peanut oral immunotherapy (OIT) among infants is effective and safe, peanut OIT could be a treatment option for infants with peanut allergy. This review discusses the benefits, risks, and barriers to offering peanut OIT to infants who fail primary prevention strategies. We propose the novel concept that infants with peanut allergy be offered peanut OIT as soon as possible after failed peanut introduction through a shared decision-making process with the family, where there is a preference for active management rather than avoidance.

Association Between Earlier Introduction of Peanut and Prevalence of Peanut Allergy in Infants in Australia

IMPORTANCE

Randomized clinical trials showed that earlier peanut introduction can prevent peanut allergy in select high-risk populations. This led to changes in infant feeding guidelines in 2016 to recommend early peanut introduction for all infants to reduce the risk of peanut allergy.

OBJECTIVE

To measure the change in population prevalence of peanut allergy in infants after the introduction of these new guidelines and evaluate the association between early peanut introduction and peanut allergy.

DESIGN

Two population-based cross-sectional samples of infants aged 12 months were recruited 10 years apart using the same sampling frame and methods to allow comparison of changes over time. Infants were recruited from immunization centers around Melbourne, Australia. Infants attending their 12-month immunization visit were eligible to participate (eligible age range, 11-15 months), regardless of history of peanut exposure or allergy history.

EXPOSURES

Questionnaires collected data on demographics, food allergy risk factors, peanut introduction, and reactions.

MAIN OUTCOME AND MEASURES

All infants underwent skin prick tests to peanut and those with positive results underwent oral food challenges. Prevalence estimates were standardized to account for changes in population demographics over time.

RESULTS

This study included 7209 infants (1933 in 2018-2019 and 5276 in 2007-2011). Of the participants in the older vs more recent cohort, 51.8% vs 50.8% were male; median (IQR) ages were 12.5 (12.2-13.0) months vs 12.4 (12.2-12.9) months. There was an increase in infants of East Asian ancestry over time (16.5% in 2018-2019 vs 10.5% in 2007-2011), which is a food allergy risk factor. After standardizing for infant ancestry and other demographics changes, peanut allergy prevalence was 2.6% (95% CI, 1.8%-3.4%) in 2018-2019, compared with 3.1% in 2007-2011 (difference, -0.5% [95% CI, -1.4% to 0.4%]; P = .26). Earlier age of peanut introduction was significantly associated with a lower risk of peanut allergy among infants of Australian ancestry in 2018-2019 (age 12 months compared with age 6 months or younger: adjusted odds ratio, 0.08 [05% CI, 0.02-0.36]; age 12 months compared with 7 to less than 10 months: adjusted odds ratio, 0.09 [95% CI, 0.02-0.53]), but not significant among infants of East Asian ancestry (P for interaction = .002).

CONCLUSIONS AND RELEVANCE

In cross-sectional analyses, introduction of a guideline recommending early peanut introduction in Australia was not associated with a statistically significant lower or higher prevalence of peanut allergy across the population.

PrEggNut Study: protocol for a randomised controlled trial investigating the effect of a maternal diet rich in eggs and peanuts from <23 weeks' gestation during pregnancy to 4 months' lactation on infant IgE-mediated egg and peanut allergy outcomes

INTRODUCTION

Clinical studies supported by immunological data indicate early life intervention strategies to be promising in reducing the growing global burden of food allergies. The events that predispose to food allergy, including the induction of allergen-specific immune responses, appear to be initiated early in development. Early exposure to food allergens in utero and via breast milk is likely to be important in initiating oral tolerance. We aim to determine the effectiveness of higher maternal food allergen consumption during pregnancy and lactation on infant food allergy outcomes.

METHODS AND ANALYSIS

This is a multisite, parallel, two-arm (1:1 allocation), single-blinded (outcome assessors, statistical analyst and investigators), randomised controlled trial. Pregnant women (<23 weeks' gestation) whose (unborn) infants have at least two biological family members (mother, father or siblings) with medically diagnosed allergic disease are eligible to participate. After obtaining written informed consent, pregnant women are randomised to either a high egg and peanut diet (at least 6 eggs and 60 peanuts per week) or standard (low) egg and peanut diet (no more than 3 eggs and 30 peanuts per week). The women are asked to follow their allocated diet from <23 weeks' gestation to 4 months' lactation. The primary outcome is food challenge proven IgE-mediated egg and/or peanut allergy in the infants at 12 months of age. Key secondary outcomes include infant sensitisation to egg and/or peanut and infant eczema. Our target sample size is 2136 women. Analyses will be performed on an intention-to-treat basis according to a pre-specified statistical analysis plan.

ETHICS AND DISSEMINATION

Ethical approval has been granted from the Women's and Children's Health Network Human Research Ethics Committee (approval number HREC/18/WCHN/42). Trial results will be presented at scientific conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry ACTRN12618000937213.

Efficacy and safety of oral immunotherapy in children aged 1-3 years with peanut allergy (the Immune Tolerance Network IMPACT trial): a randomised placebo-controlled study

BACKGROUND

For young children with peanut allergy, dietary avoidance is the current standard of care. We aimed to assess whether peanut oral immunotherapy can induce desensitisation (an increased allergic reaction threshold while on therapy) or remission (a state of non-responsiveness after discontinuation of immunotherapy) in this population.

METHODS

We did a randomised, double-blind, placebo-controlled study in five US academic medical centres. Eligible participants were children aged 12 to younger than 48 months who were reactive to 500 mg or less of peanut protein during a double-blind, placebo-controlled food challenge (DBPCFC). Participants were randomly assigned by use of a computer, in a 2:1 allocation ratio, to receive peanut oral immunotherapy or placebo for 134 weeks (2000 mg peanut protein per day) followed by 26 weeks of avoidance, with participants and study staff and investigators masked to group treatment assignment. The primary outcome was desensitisation at the end of treatment (week 134), and remission after avoidance (week 160), as the key secondary outcome, were assessed by DBPCFC to 5000 mg in the intention-to-treat population. Safety and immunological parameters were assessed in the same population. This trial is registered on ClinicalTrials.gov, NCT03345160.

FINDINGS

Between Aug 13, 2013, and Oct 1, 2015, 146 children, with a median age of 39·3 months (IQR 30·8-44·7), were randomly assigned to receive peanut oral immunotherapy (96 participants) or placebo (50 participants). At week 134, 68 (71%, 95% CI 61-80) of 96 participants who received peanut oral immunotherapy compared with one (2%, 0·05-11) of 50 who received placebo met the primary outcome of desensitisation (risk difference [RD] 69%, 95% CI 59-79; p<0·0001). The median cumulative tolerated dose during the week 134 DBPCFC was 5005 mg (IQR 3755-5005) for peanut oral immunotherapy versus 5 mg (0-105) for placebo (p<0·0001). After avoidance, 20 (21%, 95% CI 13-30) of 96 participants receiving peanut oral immunotherapy compared with one (2%, 0·05-11) of 50 receiving placebo met remission criteria (RD 19%, 95% CI 10-28; p=0·0021). The median cumulative tolerated dose during the week 160 DBPCFC was 755 mg (IQR 0-2755) for peanut oral immunotherapy and 0 mg (0-55) for placebo (p<0·0001). A significant proportion of participants receiving peanut oral immunotherapy who passed the 5000 mg DBPCFC at week 134 could no longer tolerate 5000 mg at week 160 (p<0·001). The participant receiving placebo who was desensitised at week 134 also achieved remission at week 160. Compared with placebo, peanut oral immunotherapy decreased peanut-specific and Ara h2-specific IgE, skin prick test, and basophil activation, and increased peanut-specific and Ara h2-specific IgG4 at weeks 134 and 160. By use of multivariable regression analysis of participants receiving peanut oral immunotherapy, younger age and lower baseline peanut-specific IgE was predictive of remission. Most participants (98% with peanut oral immunotherapy vs 80% with placebo) had at least one oral immunotherapy dosing reaction, predominantly mild to moderate and occurring more frequently in participants receiving peanut oral immunotherapy. 35 oral immunotherapy dosing events with moderate symptoms were treated with epinephrine in 21 participants receiving peanut oral immunotherapy.

INTERPRETATION

In children with a peanut allergy, initiation of peanut oral immunotherapy before age 4 years was associated with an increase in both desensitisation and remission. Development of remission correlated with immunological biomarkers. The outcomes suggest a window of opportunity at a young age for intervention to induce remission of peanut allergy.

FUNDING

National Institute of Allergy and Infectious Disease, Immune Tolerance Network.

Early Peanut Introduction and Testing: A Framework for General Pediatrician Beliefs and Practices

Background: Peanut introduction guidelines have undergone significant reversal since 2001 from recommending delayed introduction to rescinding the recommendations in 2008 to actively recommending early introduction of peanut between 4 and 11 months of age in high-risk infants in 2015. This qualitative study aims to explore pediatrician beliefs, practices, facilitators, and barriers regarding peanut introduction and testing. Methods: General pediatricians from academic, private, large group, and underserved practices in Northern California underwent individual semi-structured interviews in 2017. We asked about experiences surrounding infant peanut introduction, strategies for staying up-to-date with current recommendations, and barriers and facilitators to the new peanut introduction and testing recommendations. The data were coded, and using grounded theory methodology, a conceptual framework was developed around early peanut introduction and testing in infants. Results: Eighteen general pediatricians participated. We identified barriers that may contribute to pediatrician reluctance to recommending early peanut introduction or testing including lack of awareness, lack of agreement, lack of resources, and lack of outcome expectancy. A framework was created that suggests that pediatricians need to be knowledgeable about new recommendations, agree with the recommendations, have resources to carry out the counseling and testing, and have buy-in from the parents in order for successful uptake of peanut introduction guidelines. Conclusion: Recommending early peanut introduction or testing causes significant apprehension in some pediatricians, and there are many barriers to following recent early peanut introduction recommendations. A potential limitation of the study is that it was conducted right after the addendum guidelines were changed, leaving the possibility that attitudes and practices may have evolved since 2017. It is still likely that a multifaceted approach that addresses primary care provider guideline awareness, limited primary care resources for education and testing, and includes support and collaboration from subspecialty practices is more likely to lead to improved early peanut introduction uptake.

A Consensus Approach to the Primary Prevention of Food Allergy Through Nutrition: Guidance from the American Academy of Allergy, Asthma, and Immunology; American College of Allergy, Asthma, and Immunology; and the Canadian Society for Allergy and Clinical Immunology

Recently published data from high-impact randomized controlled trials indicate the strong potential of strategies to prevent the development of food allergy in high-risk individuals, but guidance in the United States at present is limited to a policy for only the prevention of peanut allergy, despite other data being available and several other countries advocating early egg and peanut introduction. Eczema is considered the highest risk factor for developing IgE-mediated food allergy, but children without risk factors still develop food allergy. To prevent peanut and/or egg allergy, both peanut and egg should be introduced around 6 months of life, but not before 4 months. Screening before introduction is not required, but may be preferred by some families. Other allergens should be introduced around this time as well. Upon introducing complementary foods, infants should be fed a diverse diet, because this may help foster prevention of food allergy. There is no protective benefit from the use of hydrolyzed formula in the first year of life against food allergy or food sensitization. Maternal exclusion of common allergens during pregnancy and/or lactation as a means to prevent food allergy is not recommended. Although exclusive breast-feeding is universally recommended for all mothers, there is no specific association between exclusive breast-feeding and the primary prevention of any specific food allergy.

Assessment of Pediatrician Awareness and Implementation of the Addendum Guidelines for the Prevention of Peanut Allergy in the United States

Importance

The 2017 Addendum Guidelines for the Prevention of Peanut Allergy in the United States recommend that pediatricians assess infant peanut allergy risk and introduce peanut in the diet at age 4 to 6 months. Early introduction has the potential to prevent peanut allergy development.

Objectives

To measure the rates of guideline awareness and implementation and to identify barriers to and factors associated with implementation among US pediatricians.

Design, Setting, and Participants

This population-based study survey used a 29-item electronic survey instrument that was administered to pediatricians practicing across the United States from June 1, 2018, to December 1, 2018. Invitations to complete a survey were emailed to all pediatricians in the American Academy of Pediatrics vendor database. Eligible participants were nonretired US-based pediatricians providing general care to infants aged 12 months or younger.

Main Outcomes and Measures

The primary outcome was the prevalence of guideline implementation, which was measured by 1 survey item about awareness followed by a second item about implementation. Secondary outcomes included identification of guidelines-focused services provided by pediatricians, knowledge of the guidelines (measured with 3 clinical scenarios), barriers to guideline implementation, need for training, and facilitators of guideline implementation.

Results

A total of 1781 pediatricians were eligible to participate and completed the entire survey. Most respondents self-identified as white (1287 [72.5%]) and female (1210 [67.4%]) individuals. Overall, 1725 (93.4%; 95% CI, 92.2%-94.5%) pediatricians reported being aware of the guidelines. Of those pediatricians who had knowledge of the guidelines, 497 (28.9%; 95% CI, 26.8%-31.1%) reported full implementation and 1105 (64.3%; 95% CI, 62.0%-66.6%) reported partial implementation. Common barriers to implementation included parental concerns about allergic reactions (reported by 575 respondents [36.6%; 95% CI, 34.3%-39.1%]), uncertainty in understanding and correctly applying the guidelines (reported by 521 respondents [33.2%; 95% CI, 30.9%-35.6%]), and conducting in-office supervised feedings (reported by 509 respondents [32.4%; 95% CI, 30.1%-34.8%]). Many pediatricians (1175 [68.4%; 95% CI, 66.1%-70.5%]) reported a need for further training on the guidelines.

Conclusions and Relevance

This survey found that most pediatrician respondents appeared to know of the 2017 guidelines, but less than one-third of respondents reported full implementation. Results of this study may inform future efforts to eliminate barriers to guideline implementation and adherence, thereby reducing the incidence of peanut allergy in infants.

Determining Levers of Cost-effectiveness for Screening Infants at High Risk for Peanut Sensitization Before Early Peanut Introduction

IMPORTANCE

Early peanut introduction reduces the risk of developing peanut allergy, especially in high-risk infants. Current US recommendations endorse screening but are not cost-effective relative to other international strategies.

OBJECTIVE

To identify scenarios in which current early peanut introduction guidelines would be cost-effective.

DESIGN, SETTING, AND PARTICIPANTS

This simulation/cohort economic evaluation used microsimulations and cohort analyses in a Markov model to evaluate the cost-effectiveness of early peanut introduction with and without peanut skin prick test (SPT) screening in high-risk infants during an 80-year horizon from a societal perspective. Data were analyzed from April to May 2019.

EXPOSURES

High-risk infants with early-onset eczema and/or egg allergy underwent early peanut introduction with and without peanut SPT screening (100 000 infants per treatment strategy) using a dichotomous 8-mm SPT cutoff value (stipulated in the current US guideline).

MAIN OUTCOMES AND MEASURES

Cost, quality-adjusted life-years (QALYs), net monetary benefit, peanut allergic reactions, severe allergic reactions, and deaths due to peanut allergy.

RESULTS

In the simulated cohort of 200 000 infants and using the base case during the model horizon, a no-screening approach had lower mean (SD) costs ($13 449 [$38 163] vs $15 279 [$38 995]) and higher mean (SD) gain in QALYs (29.25 [3.28] vs 29.23 [3.30]) vs screening but resulted in more allergic reactions (mean [SD], 1.07 [3.15] vs 1.01 [3.02]), severe allergic reactions (mean [SD], 0.53 [1.66] vs 0.52 [1.62]), and anaphylaxis involving cardiorespiratory compromise (mean [SD], 0.50 [1.59] vs 0.49 [1.47]) per individual. In deterministic SPT sensitivity analyses at base-case sensitivity and specificity rates, screening could be cost-effective at a high disutility rate (the negative effect of a food allergic reaction) (76-148 days of life traded) for an at-home vs in-clinic reaction in combination with high baseline peanut allergy prevalence among infants at high risk for peanut allergy and not yet exposed to peanuts. If an equivalent rate and disutility of accidental and index anaphylaxis was assumed and the 8-mm SPT cutoff had 0.85 sensitivity and 0.98 specificity, screening was cost-effective at a peanut allergy prevalence of 36%.

CONCLUSIONS AND RELEVANCE

The results of this study suggest that the current screening approach to early peanut introduction could be cost-effective at a particular health utility for an in-clinic reaction, SPT sensitivity and specificity, and high baseline peanut allergy prevalence among high-risk infants. However, such conditions are unlikely to be plausible to realistically achieve. Further research is needed to define the health state utility associated with reaction location.

Food allergy: Diagnosis and treatment

Immunoglobulin E-mediated food reactions usually develop within minutes of food ingestion. Although most reactions are not life-threatening, fatalities do occur. Risk factors for fatal food-induced anaphylaxis include the presence of asthma (a risk factor for anaphylaxis in general), failure to use epinephrine autoinjectors promptly, a history of severe reactions, known food allergy, denial of symptoms, and adolescent and young adult age. The most commonly implicated foods are cow's milk, egg, peanut, soy, tree nuts, fish, shellfish, and wheat. Peanut, tree nuts, and seafood are the most common food allergens in adults, whereas cow's milk, peanut, egg, soy, and wheat are more common in children. The major food allergens are glycoproteins, which are generally water soluble and stable to the effects of heat, proteases, and acids. Recent studies showed that natural tolerance can be acquired at a later age than previously thought, even during adolescence. Allergies to peanut, tree nuts, and seafood are frequently life-long. Patients and their caregivers should be taught when and how to administer injectable epinephrine. In terms of primary prevention, there is evidence that early introduction, followed by ongoing regular consumption of peanut has a protective effect on the development of peanut allergy.

Prevention of food allergy

Primary prevention and secondary prevention in the context of food allergy refer to prevention of the development of sensitization (i.e., the presence of food-specific immunoglobulin E (IgE) as measured by skin-prick testing and/or laboratory testing) and sensitization plus the clinical manifestations of food allergy, respectively. Until recently, interventions that target the prevention of food allergy have been limited. Although exclusive breast-feeding for the first 6 months of life has been a long-standing recommendation due to associated health benefits, recommendations regarding complementary feeding in infancy have significantly changed over the past 20 years. There now is evidence to support early introduction of peanut into the diet of infants with egg allergy, severe atopic dermatitis, or both diagnoses, defined as high risk for peanut allergy, to try to prevent development of peanut allergy. Although guideline-based recommendations are not available for early introduction of additional allergenic foods, this topic is being actively studied. There is no evidence to support additional dietary modification of the maternal or infant diet for the prevention of food allergy. Similarly, there is no conclusive evidence to support maternal avoidance diets for the prevention of food allergy.

Update on peanut allergy: Prevention and immunotherapy

Background: The prevalence of food allergy is steadily increasing, and the burden of food allergy has become significant. However, treatments for food allergy remain experimental. Objective: To review advances in the past 18 months for the prevention and treatment of food allergies, with a particular focus on peanut allergy. Methods: Recently published trials on the use of oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) as well as updates on the implementation of the early introduction of peanut guidelines were identified. Results: To address the slow implementation of the early introduction of peanut guidelines, addendum guidelines were published by the National Institute of Allergy and Infectious Diseases, which provide broader and more practical guidelines across a wider range of patients. Well-known studies of OIT have supported its efficacy. Recent studies have shown the potential for sustained unresponsiveness (SU) in up to 50% of subjects after peanut OIT and an even higher proportion in toddlers who received peanut OIT. Adjustments in the protocol to address practicality and safety have shown potential for lower maintenance doses and faster buildups. Longer durations of peanut SLIT have shown successful desensitization to moderate amounts of peanut and may also show the potential for SU. EPIT has maintained an excellent safety profile with statistically significant response rates in children <11 years of age. Conclusion: Advances in food immunotherapy have continued to push the field forward and provided a better understanding of the safety and efficacy of OIT, SLIT, and EPIT. These treatments remain experimental, although phase III studies are currently underway.

Solid Food Introduction and the Development of Food Allergies

The rise of food allergy in childhood, particularly among developed countries, has a significant weight on public health and involves serious implications for patients' quality of life. Even if the mechanisms of food tolerance and the complex interactions between the immune system and environmental factors are still mainly unknown, pediatricians have worldwide implemented preventive measures against allergic diseases. In the last few decades, the prevention of food allergy has tracked various strategies of complementary feeding with a modification of international guidelines from delayed introduction to early weaning. Current evidence shows that complementary foods, including allergenic ones, should be introduced into diet after four months, or even better, following World Health Organization advice, around six months irrespective of risk for allergy of the individual. The introduction of peanut is recommended before 12 months of age among infants affected by severe eczema and/or egg allergy to diminish the occurrence of peanut allergy in countries with high peanut consumption. The introduction of heated egg at 6⁻8 months of age may reduce egg allergy. Infants at high risk of allergy similarly to healthy children should introduce complementary foods taking into account family and cultural preferences.

Recent advances in understanding and preventing peanut and tree nut hypersensitivity

Peanut allergy, the most persistent and deadly of the food allergies, has become more prevalent worldwide in recent decades. Numerous explanations have been offered for the rise in peanut allergy, which has been more pronounced in Western, industrialized nations. In infants who are at increased risk of peanut allergy, new evidence indicates that early introduction of peanuts can help prevent allergy development. This counterintuitive finding directly contradicts the previously established practice of peanut avoidance for high-risk infants but is supported by clinical and basic science evidence. Here, we review the literature contributing to our evolving understanding of nut allergy, emphasizing the translation of this work to clinical practice.

Purification and Characterization of Naturally Occurring Post-Translationally Cleaved Ara h 6, an Allergen That Contributes Substantially to the Allergenic Potency of Peanut

The 2S albumin Ara h 6 is one of the most important peanut allergens. A post-translationally cleaved Ara h 6 (pAra h 6) was purified from Virginia type peanuts, and the cleavage site was mapped using high-resolution mass spectrometry. Compared to intact Ara h 6, pAra h 6 lacks a 5-amino acid stretch, resembling amino acids 43-47 (UniProt accession number Q647G9) in the nonstructured loop. Consequently, pAra h 6 consists of two chains: an N-terminal chain of approximately 5 kDa and a C-terminal chain of approximately 9 kDa, held together by disulfide bonds. Intermediate post-translationally cleaved products, in which this stretch is cleaved yet still attached to one of the subunits, are also present. The secondary structure and immunoglobulin E (IgE) binding of pAra h 6 resembles that of intact Ara h 6, indicating that the loss of the nonstructured loop is not critical for maintaining the protein structure. Commercially available monoclonal and polyclonal immunoglobulin G (IgG) antibodies directed to Ara h 6 react with both intact Ara h 6 and pAra h 6, suggesting that the involved epitopes are not located in the area that is post-translationally cleaved. No differences between intact Ara h 6 and pAra h 6 in terms of IgE binding were found, suggesting that the area that is post-translationally cleaved is not involved in IgE epitopes either. For all main cultivars Runner, Virginia, Valencia, and Spanish, intact Ara h 6 and pAra h 6 occur in peanut at similar levels, indicating that pAra h 6 is a consistent and important contributor to the allergenic potency of peanut.

Severity of peanut allergy and the unmet gaps in care: a call to action

Peanut allergy is one of the most common food allergies in children, with a prevalence that has been increasing over the past several decades. The allergy is a type I, immunoglobulin E (IgE)-mediated reaction that commonly presents in childhood and can be associated with an anaphylactic response. There are many theories that attempt to explain the increasing prevalence, including dietary changes, improvements in hygiene, and intentional allergen avoidance. Diagnosis is made through a combination of a thorough patient history, peanut-specific serum-specific IgE levels, peanut skin-prick test, and, if necessary, an oral food challenge. Guidelines based on the landmark 2015 Learning Early About Peanut Allergy trial suggest that peanuts should be introduced into the diet as early as 4 to 6 months of age in infants who are at highest risk of developing peanut allergy. It is important for providers to recognize risk factors for the development of peanut allergy, identify associated clinical symptoms, and provide an accurate diagnosis of patients to effectively manage them and their families and prevent future reactions.

Food Allergy Prevention and Treatment by Targeted Nutrition

In view of the dramatic rise in the prevalence of food allergy globally, effective prevention strategies have become a public health priority. Several models have emerged around the etiology of food allergy, including the hygiene hypothesis, dual allergen exposure hypothesis, and vitamin D hypothesis. These form the basis for current and potential prevention strategies. Breastfeeding remains a key pillar of primary allergy prevention. Other nutritional interventions, including the use of whey-based, partially hydrolyzed formula in non-breastfed infants, also play an important role. In recent years, there has been a shift away from prolonged food allergen avoidance to the proactive allergen introduction from 4 months of age. This approach is supported by 2 pivotal randomized clinical trials showing that the early introduction of peanut and other food allergens significantly reduces the risk of food allergy. However, the implementation of this strategy at the population level still raises significant logistic problems, including patient selection and development of suitable food formats for young infants. Other prevention strategies, including vitamin D supplementation, are currently under evaluation. Maternal elimination diets during pregnancy and lactation are not recommended for allergy prevention. The treatment of food allergies has also seen major transformations. While strict allergen avoidance is still the key treatment principle, there is a greater focus on desensitization and tolerance induction by oral and epicutaneous immunotherapy. In addition, specialized hypoallergenic infant formulas for the treatment of infants with cow's milk allergy have undergone reformulation, including the addition of lactose and probiotics in order to modulate the gut microbiome and early immune responses. Further research is needed to inform the most effective food allergy prevention strategies at the population level. In addition, the wider application of food allergen immunotherapy may provide better health outcomes and improved quality of life for families affected by food allergies.