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Pomés A, Smith SA, Chruszcz M, Mueller GA, Brackett NF, Chapman MD. Precision engineering for localization, validation, and modification of allergenic epitopes. J Allergy Clin Immunol 2024; 153:560-571. [PMID: 38181840 PMCID: PMC10939758 DOI: 10.1016/j.jaci.2023.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/20/2023] [Accepted: 12/29/2023] [Indexed: 01/07/2024]
Abstract
The allergen-IgE interaction is essential for the genesis of allergic responses, yet investigation of the molecular basis of these interactions is in its infancy. Precision engineering has unveiled the molecular features of allergen-antibody interactions at the atomic level. High-resolution technologies, including x-ray crystallography, nuclear magnetic resonance spectroscopy, and cryo-electron microscopy, determine allergen-antibody structures. X-ray crystallography of an allergen-antibody complex localizes in detail amino acid residues and interactions that define the epitope-paratope interface. Multiple structures involving murine IgG mAbs have recently been resolved. The number of amino acids forming the epitope broadly correlates with the epitope area. The production of human IgE mAbs from B cells of allergic subjects is an exciting recent development that has for the first time enabled an actual IgE epitope to be defined. The biologic activity of defined IgE epitopes can be validated in vivo in animal models or by measuring mediator release from engineered basophilic cell lines. Finally, gene-editing approaches using the Clustered Regularly Interspaced Short Palindromic Repeats technology to either remove allergen genes or make targeted epitope engineering at the source are on the horizon. This review presents an overview of the identification and validation of allergenic epitopes by precision engineering.
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Affiliation(s)
| | - Scott A Smith
- Vanderbilt University Medical Center, Nashville, Tenn
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Upton JEM, Wong D, Nowak-Wegrzyn A. Baked milk and egg diets revisited. Ann Allergy Asthma Immunol 2024; 132:328-336.e5. [PMID: 38151097 DOI: 10.1016/j.anai.2023.12.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 12/29/2023]
Abstract
Most children with milk and egg allergy are nonreactive to modified forms of milk and egg in bakery products such as muffins because of conformational changes in proteins. These baked milk (BM) and baked egg (BE) diets have become commonplace in the management of milk and egg allergy, respectively. Current laboratory- and skin test-based diagnostic approaches remain limited in their ability to predict BM/BE tolerance, resulting in various approaches to introduce these foods. One approach to introduce BM/BE is to offer a medically supervised oral food challenge and then advise dietary introduction of baked products for children who have tolerance. Another approach is adapted from a home-based protocol of graded ingestion of BM or BE originally intended for non-IgE mediated allergy, often referred to as a "ladder." The ladder advises home ingestion of increasing amounts of BM or BE. For children who have allergy to BM or BE, the ladder is essentially oral immunotherapy, although not always labeled or recognized as such. Risk assessment and education of patients suitable for home introduction are essential. A home approach that may be called a ladder can also be used to escalate diets after demonstrated tolerance of baked forms by introducing lesser cooked forms of milk or egg after tolerating BM or BE. A randomized controlled trial provided clear evidence that baked diets can hasten the resolution of IgE-mediated milk allergy. Moreover, BM/BE foods have an emerging role in the treatment of non-IgE-mediated allergy. There is tangential evidence for BM and BE diets in the prevention of IgE-mediated allergy.
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Affiliation(s)
- Julia E M Upton
- SickKids Food Allergy and Anaphylaxis Programme, Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children, Toronto, Canada; Division of Clinical Immunology and Allergy, Department of Pediatrics, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada; Division of Clinical Immunology and Allergy, Department of Medicine, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada.
| | - Dennis Wong
- SickKids Food Allergy and Anaphylaxis Programme, Division of Immunology and Allergy, Department of Paediatrics, The Hospital for Sick Children, Toronto, Canada; Division of Clinical Immunology and Allergy, Department of Medicine, St. Michael's Hospital, Toronto, Canada
| | - Anna Nowak-Wegrzyn
- Department of Pediatrics, Hassenfeld Children's Hospital, NYU R. Grossman School of Medicine, New York, New York; Department of Pediatrics, Gastroenterology and Nutrition, Collegium Medicum, University of Warmia and Mazury, Olsztyn, Poland
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Radulovic S, Foong R, Bartha I, Marques‐Mejias A, Krawiec M, Kwok M, Jama Z, Harrison F, Ricci C, Lack G, Du Toit G, Santos AF. Basophil activation test as predictor of severity and threshold of allergic reactions to egg. Allergy 2024; 79:419-431. [PMID: 37680143 PMCID: PMC10952485 DOI: 10.1111/all.15875] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/15/2023] [Accepted: 07/07/2023] [Indexed: 09/09/2023]
Abstract
BACKGROUND Identifying patients at risk of severe allergic reactions and/or low threshold of reactivity is very important, particularly for staple foods like egg. METHODS One hundred and fifty children underwent double-blind placebo-controlled food challenge (DBPCFC) to baked egg (BE), skin prick testing and blood collection for serology and basophil activation test (BAT). Patients who passed BE DBPCFC underwent loosely cooked egg (LCE) DBPCFC. Severity of allergic reactions was classified following Practall guidelines and threshold dose was determined during DBPCFC. RESULTS Sixty out of 150 (40%) children reacted to BE and 16 out of 77 (21%) to LCE on DBPCFC. Considering DBPCFC to BE, 23 children (38%) had severe reactions and 33 (55%) reacted to 0.13 g or less of egg protein (low threshold group). Two children (2 out of 16 = 12%) had severe reactions to LCE. Demographic, clinical and most immunological features were not significantly different between severe/non-severe BE reactors or low/high threshold groups. Severe BE reactors had higher ovomucoid-sIgE (p = .009) and higher BAT to BE (p = .001). Patients with lower threshold to BE had higher IgE-specific activity (p = .027) and BAT to egg (p = .007) but lower severity score (p = .008). Optimal cut-offs for ovomucoid-sIgE had 100% sensitivity, 35% specificity and 60% accuracy and for BAT 76% sensitivity, 74% specificity and 75% accuracy to identify BE severe reactors. Optimal cut-offs for specific activity had 70% sensitivity, 68% specificity and 69% accuracy and for BAT 70% sensitivity, 72% specificity and 71% accuracy to identify low threshold patients. CONCLUSIONS BAT was the best biomarker to predict severity and threshold of allergic reactions to BE and can be useful when making decisions about management of egg allergy.
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Affiliation(s)
- Suzana Radulovic
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Children's Allergy ServiceEvelina London Children's Hospital, Guy's and St Thomas' HospitalLondonUK
| | - Ru‐Xin Foong
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Children's Allergy ServiceEvelina London Children's Hospital, Guy's and St Thomas' HospitalLondonUK
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial SciencesKing's College LondonLondonUK
| | - Irene Bartha
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Children's Allergy ServiceEvelina London Children's Hospital, Guy's and St Thomas' HospitalLondonUK
| | - Andreina Marques‐Mejias
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Children's Allergy ServiceEvelina London Children's Hospital, Guy's and St Thomas' HospitalLondonUK
| | - Marta Krawiec
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Children's Allergy ServiceEvelina London Children's Hospital, Guy's and St Thomas' HospitalLondonUK
| | - Matthew Kwok
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial SciencesKing's College LondonLondonUK
| | - Zainab Jama
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial SciencesKing's College LondonLondonUK
| | - Faye Harrison
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial SciencesKing's College LondonLondonUK
| | - Cristian Ricci
- Africa Unit for Transdisciplinary Health Research (AUTHeR)North‐West UniversityPotchefstroomSouth Africa
| | - Gideon Lack
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Children's Allergy ServiceEvelina London Children's Hospital, Guy's and St Thomas' HospitalLondonUK
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial SciencesKing's College LondonLondonUK
| | - George Du Toit
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Children's Allergy ServiceEvelina London Children's Hospital, Guy's and St Thomas' HospitalLondonUK
| | - Alexandra F. Santos
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
- Children's Allergy ServiceEvelina London Children's Hospital, Guy's and St Thomas' HospitalLondonUK
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial SciencesKing's College LondonLondonUK
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Brasal-Prieto M, Fernández-Prades L, Dakhaoui H, Sobrino F, López-Enríquez S, Palomares F. Update on In Vitro Diagnostic Tools and Treatments for Food Allergies. Nutrients 2023; 15:3744. [PMID: 37686776 PMCID: PMC10489659 DOI: 10.3390/nu15173744] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/15/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023] Open
Abstract
Food allergy (FA) is an adverse immunological reaction to a specific food that can trigger a wide range of symptoms from mild to life-threatening. This adverse reaction is caused by different immunological mechanisms, such as IgE-mediated, non-IgE-mediated and mixed IgE-mediated reactions. Its epidemiology has had a significant increase in the last decade, more so in developed countries. It is estimated that approximately 2 to 10% of the world's population has FA and this number appears to be increasing and also affecting more children. The diagnosis can be complex and requires the combination of different tests to establish an accurate diagnosis. However, the treatment of FA is based on avoiding the intake of the specific allergenic food, thus being very difficult at times and also controlling the symptoms in case of accidental exposure. Currently, there are other immunomodulatory treatments such as specific allergen immunotherapy or more innovative treatments that can induce a tolerance response. It is important to mention that research in this field is ongoing and clinical trials are underway to assess the safety and efficacy of these different immunotherapy approaches, new treatment pathways are being used to target and promote the tolerance response. In this review, we describe the new in vitro diagnostic tools and therapeutic treatments to show the latest advances in FA management. We conclude that although significant advances have been made to improve therapies and diagnostic tools for FA, there is an urgent need to standardize both so that, in their totality, they help to improve the management of FA.
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Huang M, Yang F, Wu Y, Meng X, Shi L, Chen H, Li X. Identification of peptides sequence and conformation contributed to potential allergenicity of main allergens in yogurts. Front Nutr 2023; 9:1038466. [PMID: 36687717 PMCID: PMC9849743 DOI: 10.3389/fnut.2022.1038466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/21/2022] [Indexed: 01/07/2023] Open
Abstract
Yogurts provide a good source of nutrition and may induce tolerance in people with cow's milk allergy (CMA). This study aimed to investigate the IgE-binding capacity of main allergens in the different yogurts which provide a reference for people with a high risk of CMA, and analyze the epitopes of major allergen peptides in yogurt. We assessed the degradation and the allergenic properties of major allergens in six commercial yogurts and fresh milk. The degradation of major allergens was analyzed by SDS-PAGE and RP-HPLC. Western blot and ELISA experiments detected allergenic characteristics by using specific sera. The results showed that β-lactoglobulin (Bos d 5) and α-lactalbumin (Bos d 4) were obviously degraded in yogurts but caseins were still present in abundance, which indicated that the proteases in yogurts were specific to whey proteins. IgE and IgG binding ability of major allergens were obviously reduced in yogurts, especially GuMi yogurt. In addition, 17 peptides of major allergens in GuMi yogurt were identified by LC-MS/MS and most of them were located in the interior of the spatial structure of proteins. Among them, 8 peptides had specific biological functions for health benefits, such as antibacterial, antioxidant, and ACE-inhibitory. We also found that 6 and 14 IgE epitopes of Bos d 5 and caseins were destroyed in GuMi yogurt, which could lead to the reduction of IgE-binding capacity. Meanwhile, peptides [Bos d 5 (AA15-40), Bos d 9 (AA120-151, AA125-151)] also preserved T cell epitopes, which might also induce the development of oral tolerance. Therefore, this study suggested that the sequence and conformation of peptides in yogurts contributed to hypoallergenicity.
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Affiliation(s)
- Meijia Huang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China,School of Food Science and Technology, Nanchang University, Nanchang, China
| | - Fan Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China,School of Food Science and Technology, Nanchang University, Nanchang, China
| | - Yong Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China,Sino-German Joint Research Institute (Jiangxi-OAI), Nanchang University, Nanchang, China,Jiangxi Province Key Laboratory of Food Allergy, Nanchang University, Nanchang, China
| | - Xuanyi Meng
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China,Sino-German Joint Research Institute (Jiangxi-OAI), Nanchang University, Nanchang, China,Jiangxi Province Key Laboratory of Food Allergy, Nanchang University, Nanchang, China
| | - Linbo Shi
- School of Basic Medical Sciences, Nanchang University, Nanchang, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China,Sino-German Joint Research Institute (Jiangxi-OAI), Nanchang University, Nanchang, China,Jiangxi Province Key Laboratory of Food Allergy, Nanchang University, Nanchang, China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China,School of Food Science and Technology, Nanchang University, Nanchang, China,Jiangxi Province Key Laboratory of Food Allergy, Nanchang University, Nanchang, China,*Correspondence: Xin Li,
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Smith SA, Chruszcz M, Chapman MD, Pomés A. Human Monoclonal IgE Antibodies-a Major Milestone in Allergy. Curr Allergy Asthma Rep 2023; 23:53-65. [PMID: 36459330 PMCID: PMC9831959 DOI: 10.1007/s11882-022-01055-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2022] [Indexed: 12/04/2022]
Abstract
PURPOSE OF REVIEW Bound to its high affinity receptor on mast cells and basophils, the IgE antibody molecule plays an integral role in the allergic reaction. Through interactions with the allergen, it provides the sensitivity and specificity parameters for cell activation and mediator release that produce allergic symptoms. Advancements in human hybridoma technologies allow for the generation and molecular definition of naturally occurring allergen-specific human IgE monoclonal antibodies. RECENT FINDINGS A high-resolution structure of dust mite allergen Der p 2 in complex with Fab of the human IgE mAb 2F10 was recently determined using X-ray crystallography. The structure reveals the fine molecular details of IgE 2F10 binding its 750 Å2 conformational epitope on Der p 2. This review provides an overview of this major milestone in allergy, the first atomic resolution structure of an authentic human IgE epitope. The molecular insights that IgE epitopes provide will allow for structure-based design approaches to the development of novel diagnostics, antibody therapeutics, and immunotherapies.
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Affiliation(s)
- Scott A Smith
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
| | - Maksymilian Chruszcz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
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Boyle RJ, Shamji MH. Developments in the field of allergy in 2020 through the eyes of Clinical and Experimental Allergy. Clin Exp Allergy 2021; 51:1531-1537. [PMID: 34750898 DOI: 10.1111/cea.14046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 11/08/2021] [Indexed: 11/28/2022]
Abstract
While 2020 will be remembered for the global coronavirus pandemic, there were also important advances in the field of allergy. In this review article, we summarize key findings reported in Clinical and Experimental Allergy during 2020. We hope this provides readers with an accessible snapshot of the work published in our journal during this time.
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Affiliation(s)
- Robert J Boyle
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Mohamed H Shamji
- National Heart and Lung Institute, Imperial College London, London, UK.,NIHR Imperial Biomedical Research Centre, London, UK
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Cremonte EM, Galdi E, Roncallo C, Boni E, Cremonte LG. Adult onset egg allergy: a case report. Clin Mol Allergy 2021; 19:17. [PMID: 34602090 PMCID: PMC8489036 DOI: 10.1186/s12948-021-00156-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/03/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Egg allergy is one of the most frequent food allergies in childhood while adult onset of egg allergy is a rare condition. CASE PRESENTATION We report the case of a 30 years old man sent to our center in order to investigate gastrointestinal symptoms occurring since 2 years after egg and derivatives intake. He did not suffer from egg or other food allergies in childhood. He is an active smoker with a contact dermatitis related to nickel and mild allergic rhinoconjunctivitis to grass pollen. Skin prick test and serum specific IgE to egg were performed and revealed sensitization to egg proteins. CONCLUSIONS Even though IgE-mediated egg allergy affects children, this report witnesses a rare case of adult onset.
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Affiliation(s)
| | | | | | - Elisa Boni
- Laboratorio Unico Metropolitano, Maggiore Hospital AUSL Bologna, Largo Nigrisoli n. 2, 40133, Bologna, Italy.
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Vapor A, Mendonça A, Tomaz CT. Processes for reducing egg allergenicity: Advances and different approaches. Food Chem 2021; 367:130568. [PMID: 34343811 DOI: 10.1016/j.foodchem.2021.130568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 01/03/2023]
Abstract
Egg is a versatile ingredient and ubiquitous food. Nevertheless, egg proteins are a common cause of allergy mainly in childhood. Until now, egg eviction has been the best way to prevent this disorder, however, processed food can contribute to mitigate allergies and to guarantee life quality of allergic individuals. This review focuses on discussing and highlighting recent advances in processes to reduce egg allergenicity as well as new approaches to egg allergy management. In recent times, different methods have been developed to reduce egg allergies, by hiding the epitopes or changing the native or conformational structure of the proteins. Despite processing food has not yet been a solution to completely remove the allergenic potential of egg proteins, innovative strategies, such as addition of phenolic compounds, have been developed with promising results.
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Affiliation(s)
- Alcides Vapor
- Department of Chemistry, Faculty of Sciences, Universidade da Beira Interior, Covilhã, Portugal; CICS-UBI, Health Sciences Research Centre, Universidade da Beira Interior, Covilhã, Portugal
| | - António Mendonça
- Department of Chemistry, Faculty of Sciences, Universidade da Beira Interior, Covilhã, Portugal; CICS-UBI, Health Sciences Research Centre, Universidade da Beira Interior, Covilhã, Portugal
| | - Cândida T Tomaz
- Department of Chemistry, Faculty of Sciences, Universidade da Beira Interior, Covilhã, Portugal; CICS-UBI, Health Sciences Research Centre, Universidade da Beira Interior, Covilhã, Portugal.
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Roberts G. Farewell. Clin Exp Allergy 2020; 50:1284-1286. [PMID: 33283365 DOI: 10.1111/cea.13781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- G Roberts
- Clinical and Experimental Sciences and Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK.,NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.,The David Hide Asthma and Allergy Research Centre, St Mary's Hospital, Isle of Wight, UK
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Ehlers AM, Otten HG, Wierzba E, Flügge U, Le TM, Knulst AC, Suer W. Detection of specific IgE against linear epitopes from Gal d 1 has additional value in diagnosing hen's egg allergy in adults. Clin Exp Allergy 2020; 50:1415-1423. [PMID: 32909666 PMCID: PMC7756380 DOI: 10.1111/cea.13730] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/04/2020] [Accepted: 09/02/2020] [Indexed: 12/14/2022]
Abstract
Background Although hen's egg allergy is more prevalent in children, up to 0.6% of adults from different European countries suffer from a persistent or newly onset hen's egg allergy, making accurate diagnosis in adults necessary. However, sensitization to hen's egg extracts, components and linear epitopes is solely studied in children. Methods Hen's egg allergic (n = 16) and tolerant (n = 19) adults were selected by sensitization towards recombinant components rGal d 1 and/or 3. Sensitization profiles towards egg white and yolk extract and the native components Gal d 1, 2, 3 and 4 were respectively evaluated with the ImmunoCAP or the EUROLINE system. Characterization of linear epitopes was performed with a peptide microarray containing 15mer peptides representing the entire sequence of mature Gal d 1 and 3. Results Overall, sIgE titres against hen's egg extracts and single components overlapped largely between allergic and tolerant adults. Although the median sIgE/sIgG4 ratio to Gal d 1 was increased in allergic adults, the range was comparable between both groups. Clinically relevant sensitization to Gal d 1 was confirmed by sIgE‐binding to the linear epitopes aa30‐41, aa39‐50 or aa84‐95 in 6/13 allergic adults, mainly suffering from objective symptoms. In comparison, these epitopes were recognized by 1/15 tolerant patient. Only a few linear epitopes were detected for Gal d 3, suggesting a greater importance of conformational epitopes for the recognition of Gal d 3. Conclusion and Clinical Relevance Specific IgE‐binding to linear epitopes of Gal d 1 is highly specific in identifying hen's egg allergic adults with objective symptoms.
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Affiliation(s)
- Anna M Ehlers
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.,Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Henny G Otten
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | | | | | - Thuy-My Le
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.,Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - André C Knulst
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.,Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
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