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Zhen-Zhen Wang,1– 3,&ast; Hang Li,4,&ast; Anish R Maskey,2,&ast; Kamal Srivastava,2,5,&ast; Changda Liu,6,&ast; Nan Yang,2,5 Taoyun Xie,7 Ziyi Fu,8 Junxiong Li,9 Xiaohong Liu,10 Hugh A Sampson,6 Xiu-Min Li2,11 1Academy of Chinese Medical Science, Henan University of Chinese Medicine, Zhengzhou, Henan, People’s Republic of China; 2Department of Pathology, Microbiology & Immunology, New York Medical College, Valhalla, NY, USA; 3Collaborative Innovation Center of Research and Development on the Whole Industry Chain of Yu-Yao, Zhengzhou, Henan, People’s Republic of China; 4Central Lab, Shenzhen Bao’an Chinese Medicine Hospital, Guangzhou University of Chinese Medicine, Shenzhen, Guangdong, People’s Republic of China; 5General Nutraceutical Technology, Elmsford, NY, USA; 6Department of Pediatrics, Division of Allergy and Immunology, Icahn School of Medicine at Mount Sinai, New York, NY, USA; 7The Affiliated TCM Hospital of Guangzhou Medical University, Guangzhou, Guangdong, People’s Republic of China; 8The First Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People’s Republic of China; 9Guangdong Province Hospital of Integrated Chinese and Western Medicine, Foshan, Guangdong, People’s Republic of China; 10Department of Respiratory Medicine, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People’s Republic of China; 11Department of Otolaryngology, Westchester Medical Center New York Medical College, Valhalla, NY, USA&ast;These authors contributed equally to this workCorrespondence: Xiu-Min Li, Tel +1 914-594-4197, Email XiuMin_Li@NYMC.eduIntroduction: Neutrophil predominant airway inflammation is associated with severe and steroid-resistant asthma clusters. Previously, we reported efficacy of ASHMI, a three-herb TCM asthma formula in a steroid-resistant neutrophil-dominant murine asthma model and further identified Ganoderic Acid C1 (GAC1) as a key ASHMI active compound in vitro. The objective of this study is to investigate GAC1 effect on neutrophil-dominant, steroid-resistant asthma in a murine model.Methods: In this study, Balb/c mice were systematically sensitized with ragweed (RW) and alum and intranasally challenged with ragweed. Unsensitized/PBS challenged mice served as normal controls. Post sensitization, mice were given 4 weeks of oral treatment with GAC1 or acute dexamethasone (Dex) treatment at 48 hours prior to challenge. Pulmonary cytokines were measured by ELISA, and lung sections were processed for histology by H&E staining. Furthermore, GAC1 effect on MUC5AC expression and on reactive oxygen species (ROS) production in human lung epithelial cell line (NCI-H292) was determined by qRT-PCR and ROS assay kit, respectively. Computational analysis was applied to select potential targets of GAC1 in steroid-resistant neutrophil-dominant asthma. Molecular docking was performed to predict binding modes between GAC1 and Dex with TNF-α.Results: The result of the study showed that chronic GAC1 treatment, significantly reduced pulmonary inflammation (P < 0.01– 0.001 vs Sham) and airway neutrophilia (P < 0.01 vs Sham), inhibited TNF-α, IL-4 and IL-5 levels (P < 0.05– 0.001 vs Sham). Acute Dex treatment reduced eosinophilic inflammation and IL-4, IL-5 levels, but had no effect on neutrophilia and TNF-α production. GAC1 treated H292 cells showed decreased MUC5AC gene expression and production of ROS (P < 0.001 vs stimulated/untreated cells). Molecular docking results showed binding energy of complex GAC1-TNF was − 10.8 kcal/mol.Discussion: GAC1 may be a promising anti-asthma botanical drug for treatment of steroid-resistant asthma.Keywords: asthma, mouse model, neutrophilic inflammation, Ganoderma, ganoderic acid

This common statement of the American Academy of Allergy, Asthma and Immunology (AAAAI) and The European Academy of Allergy and Clinical Immunology (EAACI) provides an update of the 2012 published guidelines on food challenges. The guidelines equally address food challenges in the research and the clinical settings. They first address the diagnostic tests which can guide the decision to conduct a challenge. Safety of food challenges is prime, and the various procedures and safety issues as well as medications potentially involved in challenges are extensively discussed. Challenges are suggested to be conducted with semi-logarithmic incremental doses based on the protein content, typically for IgE-mediated food allergy with intervals of 20-30 min between doses. Specific protocols for other types of reactions such atopic dermatitis or gastrointestinal food allergy are detailed separately. Proper stopping criteria are essential in order to reduce the risk of false-positive diagnoses, but also severe reactions. The guidelines recommend criteria based on "go on," "stop," or "observation." These revised guidelines will clearly provide much needed guidance for food challenges in the research and clinical settings. They will continue to evolve with new diagnostic tests or new needs in the field of food allergy., (© 2024 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Immunoglobulin E (IgE)-mediated food allergies are the most common type of food allergy, often causing rapid symptoms after exposure to allergens posing a serious health risk and a high impact on patient's and caregiver's quality of life. Omalizumab, a humanized anti-IgE monoclonal antibody, reduces allergic reactions by binding to circulating IgE. Omalizumab has been successfully used in allergic asthma, chronic rhinosinusitis with nasal polyps, and chronic urticaria, and was recently approved for treating IgE-mediated food allergies by the US Food and Drug Administration (FDA). This GA 2 LEN ANACARE Consensus Statement presents our position on the use of omalizumab for treating IgE-mediated food allergies, based on a systematic review and meta-analysis, experience with use for other conditions, and expert consensus achieved via an eDelphi process. Following publication of the recent OUtMATCH study (stage 1) results and subsequent FDA approval, we propose that there is now sufficient evidence to recommend omalizumab as the only drug currently available that can mechanistically reduce IgE-mediated food allergic reactions. We acknowledge that the evidence does not reach the highest level of evidence which would be needed for a guideline recommendation., (© 2024 The Author(s). Clinical and Translational Allergy published by John Wiley & Sons Ltd on behalf of European Academy of Allergy and Clinical Immunology.)

Background: The bead-based epitope assay has been used to identify epitope-specific (es) antibodies and successfully used to diagnose clinical allergy to milk, egg, and peanut., Objective: We sought to identify es-IgE, es-IgG4, and es-IgG1 of wheat proteins and determine the optimal peptides to differentiate wheat-allergic from wheat-tolerant using the bead-based epitope assay., Methods: Children and adolescents who underwent an oral food challenge to confirm their wheat allergy status were enrolled. Seventy-nine peptides from α-/β-gliadin, γ-gliadin, ω-5-gliadin, and high- and low-molecular-weight glutenin were commercially synthesized and coupled to LumAvidin beads (Luminex Corporation, Austin, Tex). Machine learning methods were used to identify diagnostic epitopes, and performance was evaluated using the DeLong test., Results: The analysis included 122 children (83 wheat-allergic and 39 wheat-tolerant; 57.4% male). Machine learning coupled with simulations identified wheat es-IgE, but not es-IgG4 or es-IgG1, to be the most informative for diagnosing wheat allergy. Higher es-IgE binding intensity correlated with the severity of allergy phenotypes, with wheat anaphylaxis exhibiting the highest es-IgE binding intensity. In contrast, wheat-dependent exercise-induced anaphylaxis showed lower es-IgG1 binding intensity than did all the other groups. A set of 4 informative epitopes from ω-5-gliadin and γ-gliadin were the best predictors of wheat allergy, with an area under the curve of 0.908 (sensitivity, 83.4%; specificity, 88.4%), higher than the performance exhibited by wheat-specific IgE (area under the curve = 0.646; P < .001). The predictive ability of our model was confirmed in an external cohort of 71 patients (29 allergic, 42 nonallergic), with an area under the curve of 0.908 (sensitivity, 75.9%; specificity, 90.5%)., Conclusions: The wheat bead-based epitope assay demonstrated greater diagnostic accuracy compared with existing specific IgE tests for wheat allergy., Competing Interests: Disclosure statement This research project was supported by a grant from the Faculty of Medicine, Siriraj Hospital, Mahidol University (grant no. Internal Order [IO] R016232026) and by the David H. and Julia Koch Research Program in Food Allergy Research. Disclosure of potential conflict of interest: M. Suárez-Fariñas reports consultancy feeds from DBV Technologies. M. Suprun is currently an employee at Janssen Pharmaceutical. H. A. Sampson reports funding to his institution for grants from the National Institutes of Health/National Institute of Allergy and Infectious Diseases; has received consulting fees from DBV Technologies, N-Fold Therapeutics, LLC, and Siolta, Inc; and has received stock options from DBV Technologies and N-Fold Therapeutics, LLC. The rest of the authors declare that they have no relevant conflicts of interest., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: IgE-mediated food allergy and eosinophilic esophagitis (EoE) are diseases commonly triggered by milk. Milk-responsive CD4 + T cells producing type 2 cytokines are present in both diseases, yet the clinical manifestation of disease in milk allergy (MA) and EoE are distinct., Objective: We sought to identify differences in CD4 + T cells between EoE and MA that may be responsible for distinct disease manifestations., Method: The total and milk-specific CD4 + T-cell phenotype of children with MA, children with EoE (active or in remission), and controls was measured using spectral flow cytometry of peripheral blood (all groups) or esophageal biopsies (EoE and control)., Results: Circulating milk-responsive T cells could be identified in active EoE and MA. An increased frequency of T H 2A cells was also noted in MA and EoE. In circulating T cells, type 2 cytokine production was elevated in MA, but not EoE. Within the milk-responsive T follicular helper (T FH ) subset, a dichotomy of phenotype was noted: T FH 13 cells predominated in MA, while IL-10-producing T FH cells predominated in EoE. In the esophagus, CD4 + T cells were constitutively activated and expressed not only type 2 cytokines, but also IL-10 and IL-21 in active EoE. IgG4 was produced from CD38 + plasma cells in close proximity to CD4 + T cells. In vitro activation studies demonstrated that IL-10 and IL-21 elicited strong IgG4 responses in B lymphocytes, while IL-4 and IL-13 promoted IgE production., Conclusions: Our studies demonstrate a dichotomy of T FH responses that may be the basis for different clinical manifestations to milk in EoE and MA., Competing Interests: Disclosure statement Funding was provided by grant R01 AI151707 from the National Institute of Allergy and Infectious Diseases (to M.C.B. and M.C.d.L.) and pilot grants from the Mindich Child Health and Development Institute (one to M.C.B. and D.D. and one to D.L.-O.). D.L.-O. was partially funded by a postdoctoral fellowship from the Spanish Fundación Alfonso Martín Escudero. Disclosure of potential conflict of interest: H. A. Sampson reports funding to his institution from National Institutes of Health/National Institute of Allergy and Infectious Diseases grants and has received consulting fees from DBV Technologies SA, N-FOLD Therapeutics, Alpina Biotechnology, and Siolta Therapeutics unrelated to this work and stock options from DBV Technologies SA and N-FOLD Therapeutics. M. Curotto de Lafaille received consulting fees from Genentech, unrelated to this work. The rest of the authors declare that they have no conflicts of interest., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Peanut allergy treatment options remain limited, but novel approaches are being studied, including epicutaneous immunotherapy (EPIT). EPIT uses the cutaneous immune system to promote tolerance to food allergens. Viaskin™ Peanut, an approach to EPIT in late-stage clinical development uses an occlusive patch with a condensation chamber that enables natural epidermal water loss to solubilize dry antigen on the patch, which is then absorbed and captured by skin Langerhans cells. This form of EPIT does not require disruption of the skin barrier, thus avoiding a proinflammatory cytokine response by targeting the nonvascularized epidermis and limiting systemic allergen exposure. Extensive preclinical research suggests that Viaskin Peanut has a distinct mechanism of desensitization, including the potential for disease modification, driven by a unique population of regulatory T cells. Numerous clinical studies of Viaskin Peanut have demonstrated desensitization and reductions in reaction severity, particularly in children aged 1 through 11 years, as well as a favorable safety profile with mostly mild-to-moderate skin reactions that were observed to decrease over time. EPIT with Viaskin Peanut may be a potential therapeutic option for peanut allergy that is clinically practical with long-term efficacy and tolerability., (© 2024 The Author(s). Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: The basophil activation test (BAT) has been limited to research settings owing to technical issues. Novel approaches using dry, ready-to-use reagents and streamlined protocols offer greater flexibility and may open opportunities for easier implementation in clinical research., Objective: Using a streamlined basophil activation test (sBAT) strategy and the settings of the baseline study of the Epicutaneous Immunotherapy in Toddlers with Peanut Allergy (EPITOPE) trial of EPicutaneous ImmunoTherapy, we aimed to assess the feasibility of implementing BAT in a multicenter trial and to evaluate its utility in predicting the outcomes of peanut double-blind placebo-controlled food challenge (DBPCFC)., Methods: Whole blood samples were collected from subjects aged 1 to 3 years (n = 241) undergoing baseline eligibility DBPCFC in the EPITOPE study across 15 clinical sites in North America. After preparation with sBAT reagents, processed samples were analyzed in a single central laboratory within 5 days of collection and preparation. The eliciting dose (ED) at DBPCFC was determined using, Practical Allergy (PRACTALL) criteria. Using a machine learning approach that incorporated BAT-derived features, clinical characteristics, and peanut-specific immunoglobulin E, the ability to predict outcomes of interest (ED ≤ 300 mg or > 300 mg] and use of epinephrine) was assessed using data randomly split into training (n = 182) and validation (n = 59) subsets., Results: The expression of basophil activation markers CD203c and CD63 correlated with ED and severity outcomes of DBPCFC. Most informative concentrations of peanut extract in the sBAT assay for these associations were 1 ng/mL and 10 ng/mL. Using machine learning to assess the ability to predict the outcomes of DBPCFC, the best models using only the BAT-derived features provided relatively high sensitivities of 0.86 and 0.85 for predicting ED and epinephrine use, respectively, whereas specificities were lower, ranging from 0.60 to 0.80. Although including specific immunoglobulin E and skin prick test data in addition to those from sBAT did not improve the ability to identify individuals most at risk for severe reactions, it did improve the ability to identify patients with an ED greater than 300 mg., Conclusions: In addition to facilitating implementation in multicenter trials, sBAT retains the potential of BAT to characterize allergic patients and confirms its potential to contribute to predicting the outcome of oral food challenges., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

The skin is the largest immunologic organ in the body and contains immune cells that play a role in both food allergen sensitization and desensitization. The dual allergen exposure hypothesis posits that sensitization to food allergens may occur with cutaneous exposure on inflamed skin, eg, atopic dermatitis, but early oral consumption generally leads to tolerance. However, only one-third of children with atopic dermatitis develop a food allergy, suggesting that there is a more complex mechanism for allergen sensitization. Emerging evidence suggests that the outcome of cutaneous allergen exposure is context-dependent and largely influenced by the state of the skin barrier with healthy skin promoting natural tolerance. Current research supports the ability to induce desensitization through repeated application of allergens to the skin, known as epicutaneous immunotherapy. Preclinical research with an occlusive patch has demonstrated a significantly reduced T-helper cell type 2-driven immunologic response when applied to intact, uninflamed skin and induction of a unique population of regulatory T cells that express a broader range of homing receptors, which may be able to maintain sustained protection. In clinical studies of children aged 1 through 11 years with a peanut allergy, epicutaneous immunotherapy with an occlusive patch led to significant desensitization with no major differences in efficacy or safety between children with and without atopic dermatitis. These data begin to answer the conundrum of how allergens that are applied to the skin can lead to both sensitization and desensitization, and future studies should enable us to optimize the power of the skin as a complex immunologic organ to treat allergic, autoimmune, and autoinflammatory disorders., Competing Interests: Disclosures H.A.S. reports receiving funding from the National Institute of Allergy and Infectious Diseases; consulting fees from DBV Technologies, S.A., N-Fold Therapeutics, LLC, and Siolta, Inc; and stock options from DBV Technologies and N-Fold Therapeutics., (Copyright © 2024 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Reaction thresholds in peanut allergy are highly variable. Elucidating causal relationships between molecular and cellular processes associated with variable thresholds could point to therapeutic pathways for raising thresholds., Objective: The aim of this study was to characterize molecular and cellular systemic processes associated with reaction threshold in peanut allergy and causal relationships between them., Methods: A total of 105 children aged 4 to 14 years with suspected peanut allergy underwent double-blind, placebo-controlled food challenge to peanut. The cumulative peanut protein quantity eliciting allergic symptoms was considered the reaction threshold for each child. Peripheral blood samples collected at 0, 2, and 4 hours after challenge start were used for RNA sequencing, whole blood staining, and cytometry. Statistical and network analyses were performed to identify associations and causal mediation between the molecular and cellular profiles and peanut reaction threshold., Results: Within the cohort (N = 105), 81 children (77%) experienced allergic reactions after ingesting varying quantities of peanut, ranging from 43 to 9043 mg of cumulative peanut protein. Peripheral blood expression of transcripts (eg, IGF1R [false discovery rate (FDR) = 5.4e-5] and PADI4 [FDR = 5.4e-5]) and neutrophil abundance (FDR = 9.5e-4) were associated with peanut threshold. Coexpression network analyses revealed that the threshold-associated transcripts were enriched in modules for FcγR-mediated phagocytosis (FDR = 3.2e-3) and Toll-like receptor (FDR = 1.4e-3) signaling. Bayesian network, key driver, and causal mediation analyses identified key drivers (AP5B1, KLHL21, VASP, TPD52L2, and IGF2R) within these modules that are involved in bidirectional causal mediation relationships with neutrophil abundance., Conclusion: Key driver transcripts in FcγR-mediated phagocytosis and Toll-like receptor signaling interact bidirectionally with neutrophils in peripheral blood and are associated with reaction threshold in peanut allergy., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Introduction: DBV712 250 µg (also referred to as Viaskin Peanut or peanut patch; Viaskin is a trademark of DBV Technologies) is an innovative approach to epicutaneous immunotherapy (EPIT). The patch-based technology system facilitates peanut protein (allergen) absorption into the intact non-vascularized epidermis to promote desensitization to peanut while limiting systemic allergen exposure., Areas Covered: Efficacy and safety in children have been evaluated in four completed phase 3 studies. Overall, the results from these studies have demonstrated the peanut patch to be superior in desensitization compared with placebo and safe for daily use over multiple years., Expert Opinion: These findings, as well as supportive evidence from phase 2 studies, confirm the potential for an effective treatment of peanut allergy in children. The purpose of this review is to summarize the safety and efficacy of the peanut patch in the treatment of peanut allergy.

Competing Interests: Disclosures Dr Bird reports receiving grants from the National Institutes of Health/ National Institute of Allergy and Infectious Diseases (NIH/NIAID); grants and personal fees from Genentech; grants and personal fees from Novartis during the conduct of the study; grants from Aimmune, Astellas, Regeneron, and Siolta; grants and personal fees from DBV Technologies and Food Allergy Research and Education (FARE); personal fees from Allergenis, Allergy Therapeutics, HAL Allergy, and Nutricia; and other fees from the American Academy of Allergy, Asthma, and Immunology, the American Academy of Pediatrics, the International FPIES Association, and Vedanta outside the submitted work. Dr Fleischer has received research support from ARS Pharmaceuticals and DBV Technologies; serves as an unpaid advisory board member for Food Allergy and Anaphylaxis Connection Team and the National Peanut Board; receives royalties from UpToDate; and received personal fees as a consultant to Aquestive, ARS Pharmaceuticals, Bryn Pharma, DBV Technologies, Genentech, and Nasus outside of the submitted work. Dr Shreffler reports receiving grants from NIH/NIAID; has contract research support from Genentech, DBV, Allergy Therapeutics, Aravax, and Novartis; and received personal fees from Aimmune, DBV, Novartis, ALK, Allergy Therapeutics, FARE, and UpToDate. Dr Sampson reports receiving grants to his institution from NIH/NIAID; has received consulting fees from DBV Technologies, S.A., N-Fold Therapeutics, LLC, and Siolta, Inc; and has stock options from DBV Technologies and N-Fold Therapeutics. Dr Spergel reports receiving grants from NIH/NIAID and Novartis during the conduct of the study and received grants and personal fees from Regeneron and Sanofi; personal fees from ACAAI, Syneos, UpToDate, and Readysetfood; and grants from Allakos outside the submitted work.

Importance: No approved treatment exists for allergen-specific immunoglobulin E (IgE)-mediated cow's milk allergy (CMA), a common childhood food allergy., Objective: To assess dose, efficacy, and safety of epicutaneous immunotherapy with Viaskin milk in children with IgE-mediated CMA., Design, Setting, and Participants: A phase 1/2, 2-part, randomized, double-blind, placebo-controlled dose-ranging clinical trial in children aged 2 to 17 years with IgE-mediated CMA was conducted between November 2014 through December 2017. It took place at 17 trial sites in the US and Canada. Current CMA was confirmed by double-blind, placebo-controlled food challenge at study entry. Part A assessed the short-term safety of 150 μg, 300 μg, or 500 μg of Viaskin milk; part B evaluated the efficacy and safety of the 3 doses vs placebo over 12 months of treatment. Of the 308 screened participants with physician-diagnosed CMA, 198 met eligibility criteria (including an eliciting dose 300 mg or less) and were randomized., Intervention: Safety of Viaskin milk (150-μg, 300-μg, or 500-μg doses) was evaluated over a 3-week period (part A). In part B, 180 additional participants were randomized to receive Viaskin milk at doses of 150 μg, 300 μg, or 500 μg or placebo (1:1:1:1) for 12 months., Main Outcomes and Measures: The primary outcome was the proportion of treatment responders, defined as a 10-fold or more increase in the cumulative reactive dose of cow's milk protein (reaching at least 144 mg) or a cumulative reactive dose of cow's milk protein at 1444 mg or more at the month 12 double-blind, placebo-controlled food challenge., Results: A total of 95.5% of the randomized participants (mean [SD] age, 8 [4.17] years; 124 of 198 were male [62.6%]) completed treatment. The highest response rate was observed in participants who received Viaskin milk at the 300-μg dose with 24 of 49 responders (49.0%) overall vs 16 of 53 responders (30.2%) in the placebo group (odds ratio, 2.19; 95% CI, 0.91-5.41; P = .09), highest in the 2 to 11 years age group (22 of 38 [57.9%] vs 13 of 40 [32.5%]; P = .04). Most treatment-emergent adverse events were mild or moderate application-site reactions. One participant in the 500-μg Viaskin milk dose group experienced treatment-related anaphylaxis., Conclusions and Relevance: In this randomized clinical trial, 12 months of daily epicutaneous immunotherapy with a dose of Viaskin milk at 300 μg was associated with a statistically significant treatment response in 2- to 11-year-old children with IgE-mediated CMA. Treatment-related anaphylaxis and treatment-related discontinuation rates were low. Further research is needed to explore Viaskin milk as a viable treatment option for children with IgE-mediated CMA., Trial Registration: ClinicalTrials.gov Identifier: NCT02223182.

Food allergy is caused by allergen-specific immunoglobulin E (IgE) antibodies, but little is known about the B cell memory of persistent IgE responses. Here, we describe, in human pediatric peanut allergy, a population of CD23 + IgG1 + memory B cells arising in type 2 immune responses that contain high-affinity peanut-specific clones and generate IgE-producing cells upon activation. The frequency of CD23 + IgG1 + memory B cells correlated with circulating concentrations of IgE in children with peanut allergy. A corresponding population of "type 2-marked" IgG1 + memory B cells was identified in single-cell RNA sequencing experiments. These cells differentially expressed interleukin-4 (IL-4)- and IL-13-regulated genes, such as FCER2 / CD23 + , IL4R , and germline IGHE , and carried highly mutated B cell receptors (BCRs). In children with high concentrations of serum peanut-specific IgE, high-affinity B cells that bind the main peanut allergen Ara h 2 mapped to the population of "type 2-marked" IgG1 + memory B cells and included clones with convergent BCRs across different individuals. Our findings indicate that CD23 + IgG1 + memory B cells transcribing germline IGHE are a unique memory population containing precursors of high-affinity pathogenic IgE-producing cells that are likely to be involved in the long-term persistence of peanut allergy.

What Is This Summary About?: This is a summary of an article published in The New England Journal of Medicine about the EPITOPE clinical study, which tested a skin patch called ViaskinTM Peanut 250 μg (micrograms) as a treatment option for peanut allergy in children aged 1 through 3 years. The patch is a form of epicutaneous immunotherapy (EPIT), which is a new approach to allergen immunotherapy that delivers a small amount of peanut protein to the immune system through the skin. Viaskin Peanut is an investigational therapy, meaning it has not yet been approved by the United States Food and Drug Administration (FDA), that has been studied before in young children aged 4 through 11 years. In those studies, the children who received the patch were desensitized and were less likely to experience anaphylaxis when they ate peanut at the end of the study. The EPITOPE study included children aged 1 through 3 years with peanut allergy and looked at how well the peanut patch worked and how safe it was compared to a patch with no medicine (placebo, no medicine) after 12 months., What Were the Key Takeaways?: The study showed that the peanut patch was better in desensitizing children to peanuts than the placebo patch. Most of the children in the study who received the peanut patch for 12 months (the treatment group) were able to eat and tolerate more peanut at the end of the study than those who received only the placebo patch (the control group). This demonstrates that the children in the treatment group were less likely to have an allergic reaction if they ate peanut by accident at the end of the study. The children in the treatment group also had less severe symptoms when they were given peanut during the oral food challenges at the end of the study. Most children in both groups experienced side effects. Mild to moderate local skin reactions where the patch was applied were most common. These side effects happened less often and were less serious over the 12-month treatment period., What Were the Main Conclusions Reported by the Researchers?: Overall, these results show the peanut patch may be a possible treatment option to help desensitize young children with peanut allergy to peanut.

Background: Patients exquisitely sensitive to cashew/pistachio are at risk for allergic reactions to citrus seeds and pectin., Objective: In this study, we sought to evaluate whether pectin is contaminated with citrus seeds, to identify a culprit antigen in citrus seeds, and to assess for cross-reactivity among allergens in citrus seeds, citrus pectin, and cashew or pistachio., Methods: Proteins from orange seed coats, orange seed endosperms, lemon seeds, grapefruit seeds, citrus pectin, apple pectin, and grapefruit pectin were extracted. Protein concentrations in all extracts were determined and visualized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique. Immunoglobulin E-binding capacity was determined with Western blot analyses and tandem mass spectrometry for the identification of the culprit allergen in citrus seeds and pectin., Results: In subjects with citrus seed, pectin, and cashew allergies, there was strong immunoglobulin E-reactivity to bands between 17 to 28 kDa and 28 to 38 kDa. The tandem mass spectrometry analysis of these bands indicated the presence of citrin as the culprit allergen. Citrin and Ana o 2 are both 11S globulins belonging to the cupin superfamily, and significant homology was found between these proteins., Conclusion: Citrus pectin may be contaminated with citrus seeds. Citrin, a newly identified allergen in citrus seeds, seems to be the culprit antigen in citrus seeds and contaminated citrus pectin. Citrin is highly homologous with Ana o 2 in cashew and Pis v 2 in pistachio, suggesting potential for cross-reactivity and providing an explanation for co-allergenicity of cashew or pistachio, citrus seeds, and citrus pectin., (Copyright © 2023 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

This European Academy of Allergy and Clinical Immunology guideline provides recommendations for diagnosing IgE-mediated food allergy and was developed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Food allergy diagnosis starts with an allergy-focused clinical history followed by tests to determine IgE sensitization, such as serum allergen-specific IgE (sIgE) and skin prick test (SPT), and the basophil activation test (BAT), if available. Evidence for IgE sensitization should be sought for any suspected foods. The diagnosis of allergy to some foods, such as peanut and cashew nut, is well supported by SPT and serum sIgE, whereas there are less data and the performance of these tests is poorer for other foods, such as wheat and soya. The measurement of sIgE to allergen components such as Ara h 2 from peanut, Cor a 14 from hazelnut and Ana o 3 from cashew can be useful to further support the diagnosis, especially in pollen-sensitized individuals. BAT to peanut and sesame can be used additionally. The reference standard for food allergy diagnosis is the oral food challenge (OFC). OFC should be performed in equivocal cases. For practical reasons, open challenges are suitable in most cases. Reassessment of food allergic children with allergy tests and/or OFCs periodically over time will enable reintroduction of food into the diet in the case of spontaneous acquisition of oral tolerance., (© 2023 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: Rising rates of peanut allergy (PA) motivate investigations of its development to inform prevention and therapy. Microbiota and the metabolites they produce shape food allergy risk., Objective: We sought to gain insight into gut microbiome and metabolome dynamics in the development of PA., Methods: We performed a longitudinal, integrative study of the gut microbiome and metabolome of infants with allergy risk factors but no PA from a multicenter cohort followed through mid-childhood. We performed 16S rRNA sequencing, short chain fatty acid measurements, and global metabolome profiling of fecal samples at infancy and at mid-childhood., Results: In this longitudinal, multicenter sample (n = 122), 28.7% of infants developed PA by mid-childhood (mean age 9 years). Lower infant gut microbiome diversity was associated with PA development (P = .014). Temporal changes in the relative abundance of specific microbiota and gut metabolite levels significantly differed in children who developed PA. PA-bound children had different abundance trajectories of Clostridium sensu stricto 1 sp (false discovery rate (FDR) = 0.015) and Bifidobacterium sp (FDR = 0.033), with butyrate (FDR = 0.045) and isovalerate (FDR = 0.036) decreasing over time. Metabolites associated with PA development clustered within the histidine metabolism pathway. Positive correlations between microbiota, butyrate, and isovalerate and negative correlations with histamine marked the PA-free network., Conclusion: The temporal dynamics of the gut microbiome and metabolome in early childhood are distinct for children who develop PA. These findings inform our thinking on the mechanisms underlying and strategies for potentially preventing PA., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Given the potent immunological properties of the skin, epicutaneous immunotherapy (EPIT) emerges as a promising treatment approach for inducing immune tolerance, particularly for food allergies. Targeting the highly immunocompetent, non-vascularized epidermis allows for the application of microgram amounts of allergen while significantly reducing the risk of allergen passage into the bloodstream, thus limiting systemic allergen exposure and distribution. This makes EPIT highly suitable for the treatment of potentially life-threatening allergies such as food allergies. Multiple approaches to EPIT are currently under investigation for the treatment of food allergy, and these include the use of allergen-coated microneedles, application of allergen on the skin pretreated by tape stripping, abrasion or laser-mediated microperforation, or the application of allergen on the intact skin using an occlusive epicutaneous system. To date, the most clinically advanced approach to EPIT is the Viaskin technology platform. Viaskin is an occlusive epicutaneous system (patch) containing dried native allergen extracts, without adjuvants, which relies on frequent application for the progressive passage of small amounts of allergen to the epidermis through occlusion of the intact skin. Numerous preclinical studies of Viaskin have demonstrated that this particular approach to EPIT can induce potent and long-lasting T-regulatory cells with broad homing capabilities, which can exert their suppressive effects in multiple organs and ameliorate immune responses from different routes of allergen exposure. Clinical trials of the Viaskin patch have studied the efficacy and safety for the treatment of life-threatening allergies in younger patients, at an age when allergic diseases start to occur. Moreover, this treatment approach is designed to provide a non-invasive therapy with no restrictions on daily activities. Taken together, the preclinical and clinical data on the use of EPIT support the continued investigation of this therapeutic approach to provide improved treatment options for patients with allergic disorders in the near future., Competing Interests: P-LH, VD, KM, KB, and DC were employed by DBV Technologies, SA, at the time of writing this review and hold shares in DBV Technologies, SA. HS receives funding to his institution for grants from NIH/NIAID and has received consulting fees from DBV Technologies, SA; N-Fold Therapeutics, LLC; Siolta Therapeutics, Inc.; and AbbVie, and stock options from DBV Technologies, SA, and N-Fold Therapeutics, LLC. The handling editor MK declared a past co-authorship with the author HS. This study was supported by DBV Technologies. DBV Technologies was involved in the writing of the manuscript and decision to submit., (© 2023 Hervé, Dioszeghy, Matthews, Bee, Campbell and Sampson.)

Background: Gut microbiota influence food allergy. We showed that the natural compound berberine reduces IgE and others reported that BBR alters gut microbiota implying a potential role for microbiota changes in BBR function., Objective: We sought to evaluate an oral Berberine-containing natural medicine with a boiled peanut oral immunotherapy (BNP) regimen as a treatment for food allergy using a murine model and to explore the correlation of treatment-induced changes in gut microbiota with therapeutic outcomes., Methods: Peanut-allergic (PA) mice, orally sensitized with roasted peanut and cholera toxin, received oral BNP or control treatments. PA mice received periodic post-therapy roasted peanut exposures. Anaphylaxis was assessed by visualization of symptoms and measurement of body temperature. Histamine and serum peanut-specific IgE levels were measured by ELISA. Splenic IgE + B cells were assessed by flow cytometry. Fecal pellets were used for sequencing of bacterial 16S rDNA by Illumina MiSeq. Sequencing data were analyzed using built-in analysis platforms., Results: BNP treatment regimen induced long-term tolerance to peanut accompanied by profound and sustained reduction of IgE, symptom scores, plasma histamine, body temperature, and number of IgE + B cells ( p < 0.001 vs Sham for all). Significant differences were observed for Firmicutes / Bacteroidetes ratio across treatment groups. Bacterial genera positively correlated with post-challenge histamine and PN-IgE included Lachnospiraceae , Ruminococcaceae , and Hydrogenanaerobacterium (all Firmicutes ) while Verrucromicrobiacea . Caproiciproducens , Enterobacteriaceae , and Bacteroidales were negatively correlated., Conclusions: BNP is a promising regimen for food allergy treatment and its benefits in a murine model are associated with a distinct microbiota signature., Competing Interests: X-ML received research support to her institution from the National Institutes of Health NIH/National Center for Complementary and Alternative Medicine NCCAM#1P01AT002644725-01” Center for Chinese Herbal Therapy CHT for Asthma”, and grant #1 R01AT001495-01A1 and 2R01AT001495-05A2, NIH/NIAIDR43AI148039, Food Allergy Research and Education FARE,Winston Wolkoff Integrative Medicine Fund for Allergies and Wellness, the Parker Foundation and Henan University of Chinese Medicine; received consultancy fees from FARE and Johnson & Johnson Pharmaceutical Research & Development, L.L.C. received travel expenses from the NCCAM and FARE; shares US patent US7820175B2 FAHF-2, US10500169B2 XPP, US10406191B2 S. Flavescens, US10028985B2 WL; US11351157B2 nanoBBR: takes compensation from her practice at Center for Integrative Health and Acupuncture PC; US Times Technology Inc is managed by her related party; is a member of General Nutraceutical Technology LLC and Health Freedom LLC. NY received research support from the National Institutes of Health NIH/National Center for Complementary and Alternative Medicine NCCAM, NIH/NIAID R43AI148039; shares US patent: US10500169B2 XPP, US10406191B2 S. Flavescens, US10028985B2 WL; and is a member of General Nutraceutical Technology LLC and Health Freedom LLC. HS shares US patents US7820175B2 FAHF-2, US10500169B2 XPP, and US10406191B2 S. Flavescens. KS shares the patent US11351157B2 nanoBBR. Author KS was a member of General Nutraceutical Technology LLC. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Srivastava, Cao, Fidan, Shi, Yang, Nowak-Wegrzyn, Miao, Zhan, Sampson and Li.)

Background: Oral immunotherapy (OIT) is limited by adverse events, and most patients require continued treatment to maintain their increased threshold. Adjunctive treatments have been explored to increase the safety and efficacy of OIT., Objective: This study aimed to determine the safety and efficacy of enhanced, butanol purified Food Allergy Herbal Formula-2 (E-B-FAHF-2) for inducing remission in subjects undergoing omalizumab-facilitated multiallergen OIT (multi-OIT)., Methods: In this double-blind, placebo-controlled clinical trial, subjects were randomized 1:1 to receive either E-B-FAHF-2 or placebo, starting 2 months before OIT and continuing throughout OIT. All subjects received a 4-month course of omalizumab, starting 2 months before OIT through the 2-month OIT build-up phase. After 24 months of multi-OIT (maintenance dose of 1000 mg of each allergen), desensitization and remission were assessed. The primary objective was to determine if subjects in the E-B-FAHF-2 group (EOIT) were more likely than the placebo group (OIT) to develop remission to all 3 allergens treated with multi-OIT, as defined by the absence of dose-limiting symptoms to a cumulative dose of 4444 mg of protein after discontinuing treatment for 3 months., Results: Thirty-three subjects were randomized. A total of 63.6% were desensitized to 4444 mg of protein for each allergen at 26 months, and 24.2% met the primary outcome of remission at 29 months, with no difference between the treatment groups. There was good adherence (>85%) with study medications, with no difference between the treatment groups. There was no difference in reported overall adverse events between the treatment groups., Conclusion: Omalizumab-facilitated multifood OIT was safe and effective, and remission was achieved in about a quarter of subjects. However, outcomes were not improved by the addition of E-B-FAHF-2., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Food challenges (FCs) form the basis for assessing efficacy outcomes in interventional studies of food allergy; however, different studies have used a variety of similar but not identical criteria to define a challenge reaction, including subjective (nonobjective) symptoms occurring in a single-organ system as dose limiting., Objective: Our aim was to undertake a secondary analysis of 4 interventional studies to assess the impact of using less objective criteria to determine challenge-stop on reaction thresholds and their reproducibility., Methods: We analyzed individual participant data, including individual participant data meta-analysis, by using 3 different published challenge-stop criteria: (1) PRACTALL consesus criteria; (2) Consortium for Food Allergy Research version 3 (CoFAR v3) with at least 1 moderate- or severe-grade symptom; or (3) CoFAR v3 with at least 2 mild symptoms occurring in different organ systems. Reproducibility of challenge threshold was also assessed in participants undergoing subsequent repeat FCs., Results: Four studies, with detailed challenge data from a total of 592 participants, were included. Applying CoFAR v3 definitions for dose-limiting symptoms resulted in an underestimate of reaction thresholds compared with those in PRACTALL (P < .001) that is equivalent to almost a single dosing increment when using a semi-log dosing regimen. Reproducibility was also reduced when applying CoFAR v3 (P < .001 [n = 223]). Using the least conservative interpretation of CoFAR v3 (≥2 mild symptoms occurring in different systems) resulted in a significant overestimate of 15% when assessing oral immunotherapy efficacy. Applying a data-driven minor modification to CoFAR v3 resulted in a new set of challenge-stop criteria with validity similar to that of PRACTALL but one that is simpler to implement and in which significant gastrointestinal discomfort with observable decreased activity remains a dose-limiting symptom., Conclusion: The use of less objective symptoms to define challenge-stop compromises the reproducibility of the FC as a tool to assess efficacy outcomes in interventional studies, and potentially overestimates the efficacy of the intervention tested., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: No approved treatment for peanut allergy exists for children younger than 4 years of age, and the efficacy and safety of epicutaneous immunotherapy with a peanut patch in toddlers with peanut allergy are unknown., Methods: We conducted this phase 3, multicenter, double-blind, randomized, placebo-controlled trial involving children 1 to 3 years of age with peanut allergy confirmed by a double-blind, placebo-controlled food challenge. Patients who had an eliciting dose (the dose necessary to elicit an allergic reaction) of 300 mg or less of peanut protein were assigned in a 2:1 ratio to receive epicutaneous immunotherapy delivered by means of a peanut patch (intervention group) or to receive placebo administered daily for 12 months. The primary end point was a treatment response as measured by the eliciting dose of peanut protein at 12 months. Safety was assessed according to the occurrence of adverse events during the use of the peanut patch or placebo., Results: Of the 362 patients who underwent randomization, 84.8% completed the trial. The primary efficacy end point result was observed in 67.0% of children in the intervention group as compared with 33.5% of those in the placebo group (risk difference, 33.4 percentage points; 95% confidence interval, 22.4 to 44.5; P<0.001). Adverse events that occurred during the use of the intervention or placebo, irrespective of relatedness, were observed in 100% of the patients in the intervention group and 99.2% in the placebo group. Serious adverse events occurred in 8.6% of the patients in the intervention group and 2.5% of those in the placebo group; anaphylaxis occurred in 7.8% and 3.4%, respectively. Serious treatment-related adverse events occurred in 0.4% of patients in the intervention group and none in the placebo group. Treatment-related anaphylaxis occurred in 1.6% in the intervention group and none in the placebo group., Conclusions: In this trial involving children 1 to 3 years of age with peanut allergy, epicutaneous immunotherapy for 12 months was superior to placebo in desensitizing children to peanuts and increasing the peanut dose that triggered allergic symptoms. (Funded by DBV Technologies; EPITOPE ClinicalTrials.gov number, NCT03211247.)., (Copyright © 2023 Massachusetts Medical Society.)

Background: Variation in the use of treatments and hospitalization for anaphylaxis would suggest a lack of consensus in therapeutic approach., Objective: To evaluate trends and practice variation in the emergency department (ED) care of children with anaphylaxis in a large US cohort., Methods: We conducted a 48-site retrospective cohort study using the Pediatric Health Information System from January 2016 through September 2022. Children younger than 18 years with a primary diagnosis of anaphylaxis were included. Care trends were assessed using negative binomial regression modeling. Rates of medication use, hospitalizations, and revisits were reported as medians with interquartile ranges (IQRs)., Results: There were 42,909 ED visits for anaphylaxis, with a 4.2% per-year increase in visit incidence (95% CI, 1.8-6.7) during the study period. The median hospitalization rate was 3.5% (IQR, 2.2-6.0), and the 3-day ED revisit rate was 0.6% (IQR, 0.4-0.9). The hospital-level median use of therapies included intramuscular epinephrine (55.3%; IQR, 50.1-59.9), systemic steroids (73.8%; IQR, 63.9-81.4), antihistamines (59.9%; IQR, 53.5-65.5), H2-receptor antagonists (56.8%; IQR, 42.3-66.2), bronchodilators (15.1%; IQR, 12.5-17.0), inhaled epinephrine (1.1%; IQR, 0.6-1.9), and fluid boluses (19.8%; IQR, 11.3-29.3). Severe reactions requiring intensive care unit admission (1.5%; IQR, 0.8-2.2), vasopressors (0.3%; IQR, 0.0-0.6), and intubation (0.2%; IQR, 0.0-0.3) were rare., Conclusions: ED visits for anaphylaxis increased during the study period, but hospitalization rates were low. Substantial variation exists between EDs regarding the use of anaphylaxis therapies, supporting the need for future research to evaluate the efficacy of these medications., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Type 2 allergen-specific T cells are essential for the induction and maintenance of allergies to foods, and Tregs specific for these allergens are assumed to be involved in their resolution. However, it has not been convincingly demonstrated whether allergen-specific Treg responses are responsible for the generation of oral tolerance in humans. We observed that sustained food allergen exposure in the form of oral immunotherapy resulted in increased frequency of Tregs only in individuals with lasting clinical tolerance. We sought to identify regulatory components of the CD4 + T-cell response to food allergens by studying their functional activation over time in vitro and in vivo. Two subsets of Tregs expressing CD137 or CD25/OX40 were identified with a delayed kinetics of activation compared with clonally enriched pathogenic effector Th2 cells. Treg activation was dependent on IL-2 derived from effector T cells. In vivo exposure to peanut in the form of an oral food challenge of allergic subjects induced a delayed and persistent activation of Tregs after initiation of the allergen-specific Th2 response. The novel finding of our work is that a sustained wave of Treg activation is induced by the release of IL-2 from Th2 effector cells, with the implication that therapeutic administration of IL-2 could improve current OIT approaches., (© 2022 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Introduction: Food allergy is a significant public health problem with limited treatment options. As Food Allergy Herbal Formula 2 (FAHF-2) showed potential as a food allergy treatment, we further developed a purified version named EBF-2 and identified active compounds. We investigated the mechanisms of EBF-2 on IgE-mediated peanut (PN) allergy and its active compound, berberine, on IgE production., Methods: IgE plasma cell line U266 cells were cultured with EBF-2 and FAHF-2, and their effects on IgE production were compared. EBF-2 was evaluated in a murine PN allergy model for its effect on PN-specific IgE production, number of IgE + plasma cells, and PN anaphylaxis. Effects of berberine on IgE production, the expression of transcription factors, and mitochondrial glucose metabolism in U266 cells were evaluated., Results: EBF-2 dose-dependently suppressed IgE production and was over 16 times more potent than FAHF-2 in IgE suppression in U266 cells. EBF-2 significantly suppressed PN-specific IgE production (70%, p<0.001) and the number of IgE-producing plasma cells in PN allergic mice, accompanied by 100% inhibition of PN-induced anaphylaxis and plasma histamine release (p<0.001) without affecting IgG1 or IgG2a production. Berberine markedly suppressed IgE production, which was associated with suppression of XBP1, BLIMP1, and STAT6 transcription factors and a reduced rate of mitochondrial oxidation in an IgE-producing plasma cell line., Conclusions: EBF-2 and its active compound berberine are potent IgE suppressors, associated with cellular regulation of immunometabolism on IgE plasma cells, and may be a potential therapy for IgE-mediated food allergy and other allergic disorders., Competing Interests: X-ML received research support to her institution from the National Institutes of Health (NIH)/National Center for Complementary and Alternative Medicine (NCCAM) # 1P01AT002644725-01“Center for Chinese Herbal Therapy (CHT) for Asthma”, and grant #1R01AT001495-01A1 and 2R01 AT001495-05A2, NIH/NIAID R43AI148039, Food Allergy Research and Education (FARE), Winston Wolkoff Integrative Medicine Fund for Allergies and Wellness, the Parker Foundation and Henan University of Chinese Medicine; received consultancy fees from FARE and Johnson & Johnson Pharmaceutical Research & Development, L.L.C. Bayer Global Health LLC; received royalties from UpToDate; is an Honorary Professor of Chinese Medical University, Taichung, Taiwan; Henan University of Chinese Medicine Zhengzhou, China, and Professorial Lecture at Icahn School of Medicine at Mount Sinai, New York, NY, US; received travel expenses from the NCCAM and FARE; share US patent US7820175B2 (FAHF-2), US10500169B2 (XPP), US10406191B2 (S. Flavescens), US10028985B2 (WL); US11351157B2 (nanoBBR): take compensation from her practice at Center for Integrative Health and Acupuncture PC; US Times Technology Inc is managed by her related party; is a member of General Nutraceutical Technology LLC and Health Freedom LLC. NY received research support from the National Institutes of Health (NIH)/National Center for Complementary and Alternative Medicine (NCCAM), NIH/NIAID R43AI148039, shares US patent: US10500169B2 (XPP), US10406191B2 (S. Flavescens), US10028985B2 (WL); and is a member of General Nutraceutical Technology, LLC, and Health Freedom LLC; receives a salary from General Nutraceutical Technology, LLC. HS shares US patents: US7820175B2 (FAHF-2) and US10406191B2 (S. Flavescens), US10028985B2 (WL); is a medical consultant for General Nutraceutical Technology, LLC. KS shares US patent: US11351157B2 (nanoBBR) and received a salary from General Nutraceutical Technology LLC. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Yang, Maskey, Srivastava, Kim, Wang, Musa, Shi, Gong, Fidan, Wang, Dunkin, Chung, Zhan, Miao, Sampson and Li.)

Background: Currently, there is no laboratory test that can accurately identify children at risk of developing peanut allergy. Utilizing a subset of children randomized to the peanut avoidance arm of the LEAP trial, we monitored the development of epitope-specific (ses-)IgE and ses-IgG4 from 4-11 months to 5 years of age., Objective: The aim of the study was to evaluate the prognostic ability of epitope-specific antibodies to predict the result of an oral food challenge (OFC) at 5 years., Methods: A Bead-Based Epitope Assay was used to quantitate IgE and IgG4 to 64 sequential (linear) epitopes from Ara h 1-3 proteins at 4-11 months, 1 and 2.5 years of age in 74 subjects (38 of them with a positive OFC at 5 years). Specific IgE (sIgE) to peanut and component proteins was measured using ImmunoCAP. Machine learning methods were used to identify the earliest time point to predict 5-year outcome, developing prognostic algorithms based only on 4-11 month samples, 1-year or 2.5-year, and a combination of them. Data from 74 children were iteratively split 3:1 into training and validation sets, and machine learning models were developed to predict the 5-year outcome. A test set (n = 90) from an independent cohort was used for final evaluation., Results: Elastic-Net algorithm combining ses-IgE and IgE to Ara h 1, 2, 3, and 9 proteins could predict the 5-year peanut allergy status of LEAP participants with an average validation accuracy of 64% at baseline. Samples taken at 1 year accurately predicted a 5-year OFC outcome with 83% accuracy. This performance remained consistent when evaluated on an independent CoFAR2 cohort with an accuracy of 78% for the 1-year model., Conclusion: IgE antibody profiles at 1 year of age are predictive of peanut OFC at 5 years in children avoiding peanuts. If further confirmed, this model may enable early identification of infants who may benefit from early immunotherapeutic interventions., (© 2022 S. Karger AG, Basel.)

Food protein-induced enterocolitis syndrome (FPIES) was first described in detail in the late 20th century as a non-IgE-mediated food allergy characterized by delayed gastrointestinal symptoms after ingestion of a trigger food. Although the initial case series reported infants reacting to cow's milk- and soy-based formulas, we now recognize that FPIES affects patients across the age spectrum. This brief review highlights our evolving understanding of FPIES with a discussion of triggers, epidemiology, food challenges, and pathophysiology., (Copyright © 2022 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Epicutaneous immunotherapy (EPIT) protocols have recently been developed to restore tolerance in patients with food allergy. The mechanisms by which EPIT protocols promote desensitization rely on a profound immune deviation of pathogenic T- and B-cell responses., Objective: To date, little is known about the contribution of skin dendritic cells (skDCs) to T-cell remodeling and EPIT efficacy., Methods: We capitalized on a preclinical model of food allergy to ovalbumin (OVA) to characterize the phenotype and functions of OVA + skDCs throughout the course of EPIT., Results: Our results showed that both Langerhans cells and dermal conventional cDC1 and cDC2 subsets retained their ability to capture OVA in the skin and to migrate toward the skin-draining lymph nodes during EPIT. However, their activation/maturation status was significantly impaired, as evidenced by the gradual and selective reduction of CD86, CD40, and OVA protein expression in respective subsets. Phenotypic changes during EPIT were also characterized by a progressive diversification of single-cell gene signatures within each DC subset. Interestingly, we observed that OVA + Langerhans cells progressively lost their capacity to prime CD4 + T EFF cells, but gained regulatory T-cell stimulatory properties. In contrast, cDC1 were inefficient in priming CD4 + T EFF cells or in reactivating T MEM cells in vitro, whereas cDC2 retained moderate stimulatory properties, and progressively biased type 2 immunity toward type 1 and type 17 responses., Conclusions: Our results therefore emphasize that the acquisition of distinct phenotypic and functional specializations by skDCs during EPIT is at the cornerstone of the desensitization process., (Copyright © 2022 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Cow's milk (CM) is an increasingly common cause of severe allergic reactions, but there is uncertainty with respect to severity of reactions at low-level CM exposure, as well as the reproducibility of reaction thresholds., Objective: We undertook an individual participant data (IPD) meta-analysis of studies reporting double-blind, placebo-controlled food challenges in CM to determine the rate of anaphylaxis to low-level exposures and the reproducibility of reaction thresholds., Methods: We performed a systematic review and IPD meta-analysis of studies reporting relevant data. Authors were contacted to provide additional data and/or clarification as needed. Risk of bias was assessed using the National Institute for Clinical Excellence methodologic checklists., Results: Thirty-four studies were included, representing data from over 1000 participants. The cumulative ED 01 and ED 05 (cumulative doses causing objective symptoms in 1% and 5% of the at-risk allergic population) were 0.3 (95% confidence interval [CI], 0.2-0.5) and 2.9 (95% CI, 1.6-5.4) mg, respectively. At meta-analysis, 4.8% (95% CI, 2.0-10.9) and 4.8% (95% CI, 0.7-27.1) of individuals reacting to ≤5 mg and ≤0.5 mg of CM protein had anaphylaxis (minimal heterogeneity, I 2  = 0%). Then 110 individuals underwent repeat double-blind, placebo-controlled food challenges; the intraindividual variation in reaction threshold was limited to a ½-log change in 80% (95% CI, 65-89) of participants. Two individuals initially tolerated 5 mg CM protein but then reacted to this dose at a subsequent challenge, although neither had anaphylaxis., Conclusions: About 5% of CM-allergic individuals reacting to ED 01 or ED 05 exposure might have anaphylaxis to that dose. This equates to 5 and 24 anaphylaxis events per 10,000 patients exposed to an ED 01 or ED 05 dose, respectively, in the broader CM-allergic population. Most of these anaphylactic reactions would be mild and respond to a single dose of epinephrine., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

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., (© 2022 The Authors. Allergy published by European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Food allergy affects approximately 2-4% of children and adults. This guideline provides recommendations for managing food allergy from the Global Allergy and Asthma European Network (GA 2 LEN). A multidisciplinary international Task Force developed the guideline using the Appraisal of Guidelines for Research and Evaluation (AGREE) II framework and the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. We reviewed the latest available evidence as of April 2021 (161 studies) and created recommendations by balancing benefits, harms, feasibility, and patient and clinician experiences. We suggest that people diagnosed with food allergy avoid triggering allergens (low certainty evidence). We suggest that infants with cow's milk allergy who need a breastmilk alternative use either hypoallergenic extensively hydrolyzed cow's milk formula or an amino acid-based formula (moderate certainty). For selected children with peanut allergy, we recommend oral immunotherapy (high certainty), though epicutaneous immunotherapy might be considered depending on individual preferences and availability (moderate certainty). We suggest considering oral immunotherapy for children with persistent severe hen's egg or cow's milk allergy (moderate certainty). There are significant gaps in evidence about safety and effectiveness of the various strategies. Research is needed to determine the best approaches to education, how to predict the risk of severe reactions, whether immunotherapy is cost-effective and whether biological therapies are effective alone or combined with allergen immunotherapy., (© 2022 Published by Elsevier Inc. on behalf of World Allergy Organization.)

Background: Treatment options for peanut allergy are limited. In previous clinical trials, epicutaneous immunotherapy with a patch containing 250-μg peanut protein (Viaskin Peanut 250 μg [VP250]) was well tolerated and statistically superior to placebo in desensitizing peanut-allergic children., Objective: To examine the safety of VP250 in children, using a study design approximating potential real-world use., Methods: REAL LIfe Use and Safety of EPIT (REALISE) is a phase 3 multicenter study consisting of a 6-month, randomized, double-blind, placebo-controlled period followed by open-label active treatment. Children aged 4 to 11 years with physician diagnosis of peanut allergy received daily treatment with placebo (6 months) or VP250 (up to 36 months). Data from the 6-month, randomized, controlled phase of REALISE are reported., Results: Three hundred ninety-three children were randomized 3:1 to receive VP250 (n = 294) or placebo (n = 99) for 6 months; 284 (72.3%) children had a history of peanut anaphylaxis. According to parent diary, all participants receiving VP250 and 83.8% receiving placebo reported at least 1 episode of local skin reaction, with frequency decreasing over time. Only 4 participants (1.4%) receiving VP250 discontinued because of adverse events (AEs). Epinephrine was administered for allergic reactions attributed to VP250 in 7 children (2.4%), of whom 5 remained in the study; none involved severe anaphylaxis. Overall, AE rates were similar among participants with and without a history of peanut anaphylaxis., Conclusions: In a study designed to mirror real-world use, VP250 was observed to be well tolerated in peanut-allergic children, consistent with previous phase 2b and 3 studies., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Allergen-specific IL-4 + and IL-13 + CD4 + cells (type 2 cells) are essential for helping B cells to class-switch to IgE and establishing an allergic milieu in the gastrointestinal tract. The role of T cells in established food allergy is less clear., Objective: We examined the food allergen-specific T-cell response in participants of 2 food allergen immunotherapy trials to assess the relationship of the T-cell response to clinical phenotypes, including response to immunotherapy., Methods: Blood was obtained from 84 participants with peanut allergy and 142 participants with egg allergy who underwent double-blind placebo-controlled food challenges. Peanut- and egg-responsive T cells were identified by CD154 upregulation after stimulation with the respective extract. Intracellular cytokines and chemokine receptors were also detected. The response to peanut epicutaneous immunotherapy (Peanut Epicutaneous Phase II Immunotherapy Clinical Trial [CoFAR6]; 49 participants receiving epicutaneous immunotherapy) and egg oral immunotherapy or a baked egg diet (Baked Egg or Egg Oral Immunotherapy for Children With Egg Allergy [CoFAR7]; 92 participants) was monitored over time., Results: Peanut-specific type 2 and CCR6 + T cells were negatively correlated with each other and differently associated with immune parameters, including specific IgE level and basophil activation test result. At baseline, type 2 cells, but not CCR6 + cells, were predictive of clinical parameters, including a successfully consumed dose of peanut and baked egg tolerance. Exposure to peanut or egg immunotherapy was associated with a decrease in type 2 cell frequency. At baseline, high egg-specific type 2 cell frequency was the immune feature most predictive of oral immunotherapy failure., Conclusion: Food-specific type 2 T cells at baseline are informative of threshold of reactivity and response to immunotherapy., (Copyright © 2021 American Academy of Allergy, Asthma & Immunology. All rights reserved.)

Background: Despite a better understanding of the epidemiology, pathogenesis, and management of patients with anaphylaxis, there remain knowledge gaps. Enumerating and prioritizing these gaps would allow limited scientific resources to be directed more effectively., Objective: We sought to systematically describe and appraise anaphylaxis knowledge gaps and future research priorities based on their potential impact and feasibility., Methods: We convened a 25-member multidisciplinary panel of anaphylaxis experts. Panelists formulated knowledge gaps/research priority statements in an anonymous electronic survey. Four anaphylaxis themed writing groups were formed to refine statements: (1) Population Science, (2) Basic and Translational Sciences, (3) Emergency Department Care/Acute Management, and (4) Long-Term Management Strategies and Prevention. Revised statements were incorporated into an anonymous electronic survey, and panelists were asked to rate the impact and feasibility of addressing statements on a continuous 0 to 100 scale., Results: The panel generated 98 statements across the 4 anaphylaxis themes: Population Science (29), Basic and Translational Sciences (27), Emergency Department Care/Acute Management (24), and Long-Term Management Strategies and Prevention (18). Median scores for impact and feasibility ranged from 50.0 to 95.0 and from 40.0 to 90.0, respectively. Key statements based on median rating for impact/feasibility included the need to refine anaphylaxis diagnostic criteria, identify reliable diagnostic, predictive, and prognostic anaphylaxis bioassays, develop clinical prediction models to standardize postanaphylaxis observation periods and hospitalization criteria, and determine immunotherapy best practices., Conclusions: We identified and systematically appraised anaphylaxis knowledge gaps and future research priorities. This study reinforces the need to harmonize scientific pursuits to optimize the outcomes of patients with and at risk of anaphylaxis., (Copyright © 2021 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

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., Competing Interests: Declaration of interests SMJ reports grants from NIH-NIAID, Food Allergy Research & Education (FARE), Aimmune Therapeutic, DBV Technologies, Astellas, Sanofi, Regeneron, and Genentech; and personal fees from FARE, EMMES Corporation, and Aimmune Therapeutics. EHK reports personal fees from DBV Technologies, Aimmune Therapeutics, AllerGenis, Ukko, Vibrant America, Allakos, Kenota Health, and Duke Clinical Research Institute; and grants from FARE and the Wallace Research Foundation. KCN reports grants from NIAID, National Heart, Lung, and Blood Institute, National Institute of Environmental Health Sciences, and FARE; other fees from World Allergy Organization and Cour Pharma; other support from Before Brands, Alladapt, Latitude, IgGenix, Immune Tolerance Network (ITN), and NIH clinical research centres; and pending patent applications for inhibition of allergic reaction to peanut allergen using an IL-33 inhibitor (62/647,389), special oral formula for decreasing food allergy risk and treatment for food allergy (62/119,014), basophil activation based diagnostic allergy test (S10-392), granulocyte-based methods for detecting and monitoring immune system disorders (12/686,121), methods and assays for detecting and quantifying pure subpopulations of white blood cells in immune system disorders (12/610,940), mixed allergen compositions and methods for using the same (10/064,936), and microfluidic device and diagnostic methods for allergy testing based on detection of basophil activation (62/767,444). AN-W reports grants from NIH-NIAID, DBV Technologies, Astellas Pharma, and FARE; and grants and personal fees from Nestlé and Nutricia. RAW reports grants from NIAID, Aimmune, Astellas, DBV Technologies, Genentech, Regeneron, and Sanofi; and personal fees from UpToDate. HAS receives funding to his institution for grants from NIH-NIAID; consulting fees from DBV Technologies, N-Fold Therapeutics, and Siolta; and stock options from DBV Technologies and N-Fold Therapeutics. AMS reports grants from NIAID-ITN, FARE, Aimmune, DBV Technologies, Astellas, Sanofi, Regeneron, and Genentech; and personal fees from DBV Technologies. JW reports grants from NIAID and personal fees from DBV Technologies, ALK Abello, Genentech, and UpToDate. SBS reports grants from NIAID, Regeneron, DBV Technologies, Aimmune, Novartis, and Sanofi; and personal fees from AstraZeneca. MK reports grants from NIH and Department of Defence. JJ reports grants from NIAID. KS reports grants from NIH-NIAID. DCB reports grants from NIH-NIAID. HC reports grants from NIH-NIAID. DL reports grants from NIH-NIAID. All other authors declare no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

We investigated the interplay between genetics and oral peanut protein exposure in the determination of the immunological response to peanut using the targeted intervention in the LEAP clinical trial. We identified an association between peanut-specific IgG4 and HLA-DQA1*01:02 that was only observed in the presence of sustained oral peanut protein exposure. The association between IgG4 and HLA-DQA1*01:02 was driven by IgG4 specific for the Ara h 2 component. Once peanut consumption ceased, the association between IgG4-specific Ara h 2 and HLA-DQA1*01:02 was attenuated. The association was validated by observing expanded IgG4-specific epitopes in people who carried HLA-DQA1*01:02. Notably, we confirmed the previously reported associations with HLA-DQA1*01:02 and peanut allergy risk in the absence of oral peanut protein exposure. Interaction between HLA and presence or absence of exposure to peanut in an allergen- and epitope-specific manner implicates a mechanism of antigen recognition that is fundamental to driving immune responses related to allergy risk or protection.

Food allergy diagnosis has a massive impact on the lives of patients and their families. Despite recent developments with specific IgE to component allergens, a significant proportion of patients assessed for possible food allergy require oral food challenge to ensure an accurate diagnosis. More precise diagnostic methods are required to reduce the need for oral food challenges. Bead-based epitope assays and cellular tests, such as basophil activation and mast cell tests are the most novel and promising tests on the horizon. There is a pathway to pursue to enable their incorporation in clinical practice, including standardization, technical validation, clinical validation, external validation, overcoming practical and logistical issues, and regulatory approval. Valuable clinical application of these tests goes beyond diagnosis and includes risk assessment to identify allergic patients who are most sensitive and at risk for severe allergic reactions, and to define prognosis and assess clinical response to immunomodulatory treatments., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)