1
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Canon N, Schein CH, Braun W, Negi SS, Chen X, Kulis MD, Kim EH, Pathy V, Pozzoli M, Liu W, Dreskin SC. Alanine Scanning of the Unstructured Region of Ara h 2 and of a Related Mimotope Reveals Critical Amino Acids for IgE Binding. Mol Nutr Food Res 2023; 67:e2300134. [PMID: 37706599 PMCID: PMC10840829 DOI: 10.1002/mnfr.202300134] [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: 03/09/2023] [Revised: 07/26/2023] [Indexed: 09/15/2023]
Abstract
SCOPE The unstructured region of Ara h 2, referred to as epitope 3, contains a repeated motif, DYPSh (h = hydroxyproline) that is important for IgE binding. METHODS AND RESULTS IgE binding assays to 20mer and shorter peptides of epitope 3, defines a 16mer core sequence containing one copy of the DPYSh motif, DEDSYERDPYShSQDP. This study performs alanine scanning of this and a related 12mer mimotope, LLDPYAhRAWTK. IgE binding, using a pool of 10 sera and with individual sera, is greatly reduced when alanine is substituted for aspartate at position 8 (D8; p < 0.01), tyrosine at position 10 (Y10; p < 0.01), and hydroxyproline at position 12 (h12; p < 0.001). IgE binding to alanine-substituted peptides of a mimotope containing the DPY_h motif confirm the critical importance of Y (p < 0.01) and h (p < 0.01), but not D. Molecular modeling of the core and mimotope suggests an h-dependent conformational basis for the recognition of these sequences by polyclonal IgE. CONCLUSIONS IgE from pooled sera and individual sera differentially bound amino acids throughout the sequences of Epitope 3 and its mimotope, with Y10 and h12 being most important for all sera. These results are highly significant for designing hypoallergenic forms of Ara h 2.
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Affiliation(s)
- Nicole Canon
- Division of Allergy and Immunology, Kelsey-Seybold Clinic, Houston, TX
| | - Catherine H. Schein
- Institute for Human Infections and Immunity (IHII), The University of Texas Medical Branch, Galveston, TX
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX
| | - Surendra S. Negi
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX
| | - Xueni Chen
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Michael D. Kulis
- Division of Pediatric Allergy and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Edwin H. Kim
- Division of Pediatric Allergy and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Vidya Pathy
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Marina Pozzoli
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Weimin Liu
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Stephen C. Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
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2
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Aytekin ES, Soyer O, Sahiner UM, Wieser S, Lupinek C, Sekerel BE. Diagnostic accuracy of the ALEX 2 test in peanut-sensitized children. Clin Exp Allergy 2023; 53:1041-1044. [PMID: 37246604 DOI: 10.1111/cea.14350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 05/04/2023] [Accepted: 05/08/2023] [Indexed: 05/30/2023]
Affiliation(s)
- Elif Soyak Aytekin
- Department of Pediatric Allergy, Hacettepe University School of Medicine, Ankara, Turkey
| | - Ozge Soyer
- Department of Pediatric Allergy, Hacettepe University School of Medicine, Ankara, Turkey
| | - Umit Murat Sahiner
- Department of Pediatric Allergy, Hacettepe University School of Medicine, Ankara, Turkey
| | | | | | - Bulent Enis Sekerel
- Department of Pediatric Allergy, Hacettepe University School of Medicine, Ankara, Turkey
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3
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Brand HK, Schreurs MWJ, Emons JAM, Gerth van Wijk R, de Groot H, Arends NJT. Peanut components measured by ISAC: comparison with ImmunoCap and clinical relevance in peanut allergic children. Clin Mol Allergy 2021; 19:14. [PMID: 34372856 PMCID: PMC8353733 DOI: 10.1186/s12948-021-00153-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 07/29/2021] [Indexed: 11/18/2022] Open
Abstract
Background Specific IgE (sIgE) against the peanut component Arachis hypogaea (Ara h) 2 has been shown to be the most important allergen to discriminate between peanut allergy and peanut tolerance. Several studies determined sIgE cut off values for Ara h 2, determined by singleplex measurements. However, cut off values for Ara h 2 from multiplex arrays are less well defined. The aim of this study was to evaluate the correlation between Ara h 2 sIgE determined by singleplex versus multiplex measurements and to assess the diagnostic value of the different peanut components included in Immuno Solid-phase Allergen Chip (ISAC) multiplex analysis in children with a suspected peanut allergy. Methods In this retrospective study we analyzed Ara h 2 sIgE values with singleplex Fluorescence Enzyme Immunoassay (FEIA, ImmunoCap) and multiplex microarray (ISAC) measurements in 117 children with a suspected peanut allergy. Also, other peanut components measured by ISAC were analyzed. Double blinded placebo controlled oral food challenges were used as golden standard. Results Among all studied peanut components FEIA Ara h 2 sIgE showed the highest area under the curve (AUC, 0.922), followed by ISAC Ara h 6 and Ara h 2 sIgE with AUCs of respectively 0.906 and 0.902. Best cut off values to diagnose peanut allergy were 4.40 kU/l for FEIA Ara h 2 sIgE and, 7.43 ISU and 8.13 ISU for respectively Ara h 2 and Ara h 6 sIgE in ISAC microarray. Ara h 2 sIgE determined in FEIA and ISAC showed a good correlation (r = 0.88; p < 0.01). Conclusion Ara h 6 and Ara h 2 sIgE in multiplex ISAC are both good predictors of clinical peanut allergy in Dutch children, and their performance is comparable to the use of Ara h 2 in singleplex FEIA. The simultaneous measurement of different peanut components using ISAC is an advantage and clinically useful to detect peanut allergic children that are Ara h 2 negative but sensitized to other peanut proteins such as Ara h 6.
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Affiliation(s)
- H K Brand
- Department of Pediatric Pulmonology and Allergology, Emma Children's Hospital, Amsterdam University Medical Centres, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| | - M W J Schreurs
- Department of Immunology, Laboratory Medical Immunology, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - J A M Emons
- Department of Pediatric Pulmonology and Allergology, Erasmus MC-Sophia Children's Hospital, University Medical Center, Rotterdam, The Netherlands
| | - R Gerth van Wijk
- Department of Internal Medicine, Section of Allergology and Clinical Immunology, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - H de Groot
- Department of Allergology, Reinier de Graaf Hospital, Delft, The Netherlands
| | - N J T Arends
- Department of Pediatric Pulmonology and Allergology, Erasmus MC-Sophia Children's Hospital, University Medical Center, Rotterdam, The Netherlands
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4
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Apostolovic D, Marsh JT, Baumert J, Taylor SL, Westphal A, de Jongh H, Johnson P, de Jong GAH, Koppelman SJ. Purification and Initial Characterization of Ara h 7, a Peanut Allergen from the 2S Albumin Protein Family. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:6318-6329. [PMID: 34037388 DOI: 10.1021/acs.jafc.1c00618] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
2S albumins are important peanut allergens. Within this protein family, Ara h 2 and Ara h 6 have been described in detail, but Ara h 7 has received little attention. We now describe the first purification of Ara h 7 and its characterization. Two Ara h 7 isoforms were purified from peanuts. Mass spectrometry revealed that both the isoforms have a post-translation cleavage, a hydroxyproline modification near the N-terminus, and four disulfide bonds. The secondary structure of both Ara h 7 isoforms is highly comparable to those of Ara h 2 and Ara h 6. Both Ara h 7 isoforms bind IgE, and Ara h 7 is capable of inhibiting the binding between Ara h 2 and IgE, suggesting at least partially cross-reactive IgE epitopes. Ara h 7 was found in all main market types of peanut, at comparable levels. This suggests that Ara h 7 is a relevant allergen from the peanut 2S albumin protein family.
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Affiliation(s)
- Danijela Apostolovic
- Immunology and Allergy Division, Department of Medicine Solna, Karolinska Institutet, Solnavägen 1, 171 77 Solna, Sweden
| | - Justin T Marsh
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Joe Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Steve L Taylor
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Adrie Westphal
- Biochemistry Dept., Wageningen University and Research, PO Box 17, 6700 AA Wageningen, The Netherlands
| | - Harmen de Jongh
- ProtinConsult, Rozenstraat 19, 3702 VL Zeist, The Netherlands
| | - Phil Johnson
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Govardus A H de Jong
- Wageningen University and Research, Food and Biobased Research. PO Box 17, 6700 AA Wageningen, The Netherlands
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
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5
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Dreskin SC, Koppelman SJ, Andorf S, Nadeau KC, Kalra A, Braun W, Negi SS, Chen X, Schein CH. The importance of the 2S albumins for allergenicity and cross-reactivity of peanuts, tree nuts, and sesame seeds. J Allergy Clin Immunol 2021; 147:1154-1163. [PMID: 33217410 PMCID: PMC8035160 DOI: 10.1016/j.jaci.2020.11.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 12/17/2022]
Abstract
Allergies to peanuts, tree nuts, and sesame seeds are among the most important food-related causes of anaphylaxis. Important clinical questions include: Why is there a variable occurrence of coallergy among these foods and Is this immunologically mediated? The clinical and immunologic data summarized here suggest an immunologic basis for these coallergies that is based on similarities among the 2S albumins. Data from component resolved diagnostics have highlighted the relationship between IgE binding to these allergens and the presence of IgE-mediated food allergy. Furthermore, in vitro and in vivo experiments provide strong evidence that the 2S albumins are the most important allergens in peanuts for inducing an allergic effector response. Although the 2S albumins are diverse, they have a common disulfide-linked core with similar physicochemical properties that make them prime candidates to explain much of the observed coallergy among peanuts, tree nuts, and sesame seeds. The well-established frequency of cashew and pistachio nut coallergy (64%-100%) highlights how the structural similarities among their 2S albumins may account for observed clinical cross-reactivity. A complete understanding of the physicochemical properties of the 2S albumins in peanuts, tree nuts, and sesame seeds will enhance our ability to diagnose, treat, and ultimately prevent these allergies.
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Affiliation(s)
- Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo.
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska, Lincoln, Neb
| | - Sandra Andorf
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Division of Allergy and Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio; Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif
| | - Kari C Nadeau
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif
| | - Anjeli Kalra
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex; Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex; Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Xueni Chen
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo
| | - Catherine H Schein
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex; Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Tex.
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6
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Ranking of 10 legumes according to the prevalence of sensitization as a parameter to characterize allergenic proteins. Toxicol Rep 2021; 8:767-773. [PMID: 33854954 PMCID: PMC8027524 DOI: 10.1016/j.toxrep.2021.03.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 03/19/2021] [Accepted: 03/27/2021] [Indexed: 11/25/2022] Open
Abstract
10 different legumes extracts could be ranked based on the variations in the prevalence of sensitization. Variations in the prevalence of sensitization allowed for ranking of 18 different individual legume proteins. Ranking can be used to select reference proteins to develop predictive assays for the assessment of the sensitizing potential of novel proteins.
Predicting the allergenicity of novel proteins is challenging due to the absence of validated predictive methods and a well-defined reference set of proteins. The prevalence of sensitization could be a parameter to select reference proteins to characterize allergenic proteins. This study investigated whether the prevalence of sensitization of legume extracts and proteins can indeed be used for this purpose. A random sample of suspected food-allergic patients (n=106) was therefore selected. 10 extracts (processed and non-processed) and 18 individual proteins (2S albumins, 7S and 11S globulins) from black lentil, blue and white lupine, chickpea, faba bean, green lentil, pea, peanut, soybean, and white bean were isolated and the prevalence of sensitization and the intensity of IgE binding were evaluated. The prevalence of sensitization ranged from 5.7 % (faba bean and green lentil) to 14.2 % (peanut). The prevalence of sensitization for individual legume proteins ranged from 0.0 % for albumin 1 (pea) to 15.1 %–17.9 % for Ara h 1, 2, 3, and 6 (peanut). The prevalence of sensitization correlated strongly with the intensity of IgE binding for individual proteins (p < 0.05, ρ = 0.894), for extracts no correlation was found. The discovered ranking can be used to select reference proteins for the development and validation of predictive in vitro or in vivo assays for the assessment of the sensitizing potential.
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7
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Datema MR, Eller E, Zwinderman AH, Poulsen LK, Versteeg SA, van Ree R, Bindslev-Jensen C. Ratios of specific IgG 4 over IgE antibodies do not improve prediction of peanut allergy nor of its severity compared to specific IgE alone. Clin Exp Allergy 2018; 49:216-226. [PMID: 30269403 PMCID: PMC7379576 DOI: 10.1111/cea.13286] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 07/15/2018] [Accepted: 08/01/2018] [Indexed: 01/04/2023]
Abstract
Background IgG4 antibodies have been suggested to play a protective role in the translation of peanut sensitization into peanut allergy. Whether they have added value as diagnostic read‐out has not yet been reported. Objective To evaluate whether (a) peanut‐specific IgG, IgG4 and/or IgA antibodies are associated with tolerance and/or less severe reactions and (b) they can improve IgE‐based diagnostic tests. Methods Sera of 137 patients with challenge‐proven peanut allergy and of 25 subjects that tolerated peanut, both with known IgE profiles to peanut extract and five individual peanut allergens, were analyzed for specific IgG and IgG4. Antibody levels and ratios thereof were associated with challenge outcome including symptom severity grades. For comparison of the discriminative performance, receiver operating characteristic curve (ROC) analysis was used. Results IgE against Ara h 2 was significantly higher in allergic than in tolerant patients and associated with severity of reactions (P < 0.001) with substantial diagnostic capability (AUC 0.91, 95%CI 0.87‐0.96 and 0.80, 95%CI 0.73‐0.87, respectively). IgG and IgG4 were also positively associated albeit significantly weaker (AUCs from 0.65 to 0.72). On the other hand, ratios of IgG and IgG4 over IgE were greater in patients that were tolerant or had mild symptoms as compared to severe patients but they did not predict challenge outcomes better than IgE alone (AUCs from 0.54 to 0.89). Conclusion IgE against Ara h 2 is the best biomarker for predicting peanut challenge outcomes including severity and IgG and IgG4 antibody ratios over IgE do not improve these outcomes.
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Affiliation(s)
- Mareen R Datema
- Department of Experimental Immunology, Academic Medical Center, Amsterdam, the Netherlands.,Department of Clinical Epidemiology, Academic Medical Centre, Biostatistics and Bioinformatics, Amsterdam, the Netherlands
| | - Esben Eller
- Department of Dermatology and Allergy Center, Odense Research Center for Anaphylaxis (ORCA), Odense University Hospital, Odense, Denmark
| | - Aeilko H Zwinderman
- Department of Clinical Epidemiology, Academic Medical Centre, Biostatistics and Bioinformatics, Amsterdam, the Netherlands
| | - Lars K Poulsen
- Allergy Clinic, Copenhagen University Hospital at Gentofte, Copenhagen, Denmark
| | - Serge A Versteeg
- Department of Experimental Immunology, Academic Medical Center, Amsterdam, the Netherlands
| | - Ronald van Ree
- Department of Experimental Immunology, Academic Medical Center, Amsterdam, the Netherlands.,Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, the Netherlands
| | - Carsten Bindslev-Jensen
- Department of Dermatology and Allergy Center, Odense Research Center for Anaphylaxis (ORCA), Odense University Hospital, Odense, Denmark
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8
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Magnusdottir H, Vidarsdóttir A, Ludviksson B, Clausen M, Lund S, Jensen A, Sigurdardottir S. Ara h 1 and Ara h 6 Sensitization Causes Clinical Peanut Allergy in Ara h 2-Negative Individuals. Int Arch Allergy Immunol 2018; 178:66-75. [DOI: 10.1159/000493327] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 08/28/2018] [Indexed: 11/19/2022] Open
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9
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Stiefel G, Anagnostou K, Boyle RJ, Brathwaite N, Ewan P, Fox AT, Huber P, Luyt D, Till SJ, Venter C, Clark AT. BSACI guideline for the diagnosis and management of peanut and tree nut allergy. Clin Exp Allergy 2018; 47:719-739. [PMID: 28836701 DOI: 10.1111/cea.12957] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/01/2017] [Accepted: 05/08/2017] [Indexed: 12/17/2022]
Abstract
Peanut nut and tree nut allergy are characterised by IgE mediated reactions to nut proteins. Nut allergy is a global disease. Limited epidemiological data suggest varying prevalence in different geographical areas. Primary nut allergy affects over 2% of children and 0.5% of adults in the UK. Infants with severe eczema and/or egg allergy have a higher risk of peanut allergy. Primary nut allergy presents most commonly in the first five years of life, often after the first known ingestion with typical rapid onset IgE-mediated symptoms. The clinical diagnosis of primary nut allergy can be made by the combination of a typical clinical presentation and evidence of nut specifc IgE shown by a positive skin prick test (SPT) or specific IgE (sIgE) test. Pollen food syndrome is a distinct disorder, usually mild, with oral/pharyngeal symptoms, in the context of hay fever or pollen sensitisation, which can be triggered by nuts. It can usually be distinguish clinically from primary nut allergy. The magnitude of a SPT or sIgE relates to the probability of clinical allergy, but does not relate to clinical severity. SPT of ≥ 8 mm or sIgE ≥ 15 KU/L to peanut is highly predictive of clinical allergy. Cut off values are not available for tree nuts. Test results must be interpreted in the context of the clinical history. Diagnostic food challenges are usually not necessary but may be used to confirm or refute a conflicting history and test result. As nut allergy is likely to be a long-lived disease, nut avoidance advice is the cornerstone of management. Patients should be provided with a comprehensive management plan including avoidance advice, patient specific emergency medication and an emergency treatment plan and training in administration of emergency medication. Regular re-training is required.
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Affiliation(s)
- G Stiefel
- Leicester Royal Infirmary, Leicester, UK
| | - K Anagnostou
- Guy's and St Thomas' NHS Foundation Trust, London, UK
| | | | - N Brathwaite
- King's College Hospital NHS Foundation Trust, London, UK
| | - P Ewan
- Addenbrooke's Hospital, Cambridge, UK
| | - A T Fox
- Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - P Huber
- British Society for Allergy and Clinical Immunology, London, UK
| | - D Luyt
- Leicester Royal Infirmary, Leicester, UK
| | - S J Till
- King's College Hospital NHS Foundation Trust, London, UK
| | - C Venter
- St. Mary's Hospital, Isle of Wight, UK
| | - A T Clark
- Addenbrooke's Hospital, Cambridge, UK
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10
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Hayen SM, Ehlers AM, den Hartog Jager CF, Garssen J, Knol EF, Knulst AC, Suer W, Willemsen LEM, Otten HG. 2S protein Ara h 7.0201 has unique epitopes compared to other Ara h 7 isoforms and is comparable to 2S proteins Ara h 2 and 6 in basophil degranulation capacity. Clin Exp Allergy 2018. [DOI: 10.1111/cea.13134] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. M. Hayen
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - A. M. Ehlers
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - C. F. den Hartog Jager
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - J. Garssen
- Division of Pharmacology; Utrecht Institute for Pharmaceutical Sciences; Faculty of Science; Utrecht University; Utrecht The Netherlands
- Immunology; Nutricia Research; Utrecht The Netherlands
| | - E. F. Knol
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - A. C. Knulst
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | | | - L. E. M. Willemsen
- Division of Pharmacology; Utrecht Institute for Pharmaceutical Sciences; Faculty of Science; Utrecht University; Utrecht The Netherlands
| | - H. G. Otten
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
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11
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Blankestijn MA, Otten HG, Suer W, Weimann A, Knol EF, Knulst AC. Specific IgE to peanut 2S albumin Ara h 7 has a discriminative ability comparable to Ara h 2 and 6. Clin Exp Allergy 2017; 48:60-65. [PMID: 28906044 DOI: 10.1111/cea.13030] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/15/2017] [Accepted: 09/04/2017] [Indexed: 12/01/2022]
Abstract
BACKGROUND Little is known on the clinical relevance of peanut 2S albumin Ara h 7. OBJECTIVE To investigate the discriminative ability of Ara h 7 in peanut allergy and assess the role of cross-reactivity between Ara h 2, 6 and Ara h 7 isoforms. METHODS Sensitization to recombinant peanut storage proteins Ara h 1, 2, 3, 6, and 7 was assessed using a line blot in sera from 40 peanut-tolerant and 40 peanut-allergic patients, based on food challenge outcome. A dose-dependent ELISA inhibition experiment was performed with recombinant Ara h 2, 6 and Ara h 7 isoforms. RESULTS For Ara h 7.0201, an area under the ROC curve was found of 0.83, comparable to Ara h 2 (AUC 0.81) and Ara h 6 (AUC 0.85). Ara h 7 intensity values strongly correlated with those from Ara h 2 and 6 (rs = 0.81). Of all patients sensitized to 2S albumins Ara h 2, 6, or 7, the majority was co-sensitized to all three (n = 24, 68%), although mono-sensitization to either 2S albumin was also observed in selected patients (Ara h 2: n = 6, 17%; Ara h 6: n = 2, 6%; Ara h 7: n = 2, 6%). Binding to Ara h 7.0101 could be strongly inhibited by Ara h 7.0201, but not the other way around. CONCLUSIONS AND CLINICAL RELEVANCE Specific IgE against Ara h 7.0201 has a predictive ability for peanut allergy similar to Ara h 2 and 6 and possesses unique IgE epitopes as well as epitopes shared between the other Ara h 7 isoform and Ara h 2 and 6. While co-sensitization to all three 2S albumins is most common, mono-sensitization to either Ara h 2, 6, or 7 occurs in selected patients, leading to a risk of misdiagnosis when testing for a single 2S albumin.
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Affiliation(s)
- M A Blankestijn
- Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - H G Otten
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - W Suer
- EUROIMMUN, Lübeck, Germany
| | | | - E F Knol
- Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - A C Knulst
- Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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12
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García-Ara C, Pedrosa M, Quirce S, Caballero T, Boyano-Martínez T. Sensitization to microarrayed species-specific plant components precedes that of cross-reacting allergens. Pediatr Allergy Immunol 2017; 28:288-291. [PMID: 28140470 DOI: 10.1111/pai.12701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carmen García-Ara
- Department of Allergy, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - María Pedrosa
- Department of Allergy, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Santiago Quirce
- Department of Allergy, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Teresa Caballero
- Department of Allergy, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Teresa Boyano-Martínez
- Department of Allergy, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
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Abstract
Angioedema, as a distinct disease entity, often becomes a clinical challenge for physicians, because it may cause a life-threatening condition, whereas prompt and accurate laboratory diagnostics may not be available. Although the bedside diagnosis needs to be established based on clinical symptoms and signs, family history, and the therapeutic response, later, laboratory tests are available. Currently, only for five out of the nine different types of angioedema can be diagnosed by laboratory testing, and these occur only in a minority of the patient population. Hereditary angioedema with C1-inhibitor (C1-INH) deficiency type I can be diagnosed by the low C1-INH function and concentration, whereas in type II, C1-INH function is low, but its concentration is normal or even elevated. C1q concentration is normal in both forms. Acquired angioedema with C1-INH deficiency type I is characterized by the low C1-INH function and concentration; however, C1q concentration is also low, and autoantibodies against C1-INH cannot be detected. Complement profile of acquired angioedema with C1-INH deficiency type II is similar to that of type I, but in this form, autoantibodies against C1-INH are present. Hereditary angioedema due to a mutation of the coagulation factor XII can be diagnosed exclusively by mutation analysis of FXII gene. Diagnostic metrics are not available for idiopathic histaminergic acquired angioedema, idiopathic non-histaminergic acquired angioedema, acquired angioedema related to angiotensin-converting enzyme inhibitor, and hereditary angioedema of unknown origin; these angioedemas can be diagnosed by medical and family history, clinical symptoms, and therapeutic response and by excluding the forms previously described. Several potential biomarkers of angioedema are used to date only in research. In the future, they could be utilized into the clinical practice to improve the differential diagnosis, therapy, as well as the prognosis of angioedema.
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van der Valk JPM, Schreurs MWJ, El Bouch R, Arends NJT, de Jong NW. Mono-sensitisation to peanut component Ara h 6: a case series of five children and literature review. Eur J Pediatr 2016; 175:1227-1234. [PMID: 27206507 PMCID: PMC5005383 DOI: 10.1007/s00431-016-2733-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 03/20/2016] [Accepted: 05/11/2016] [Indexed: 11/24/2022]
Abstract
UNLABELLED Here, we summarise the current clinical knowledge on Ara h 6 sensitisation and clinical relevance of this sensitisation pattern using five illustrative clinical cases. The literature search yielded a total of 166 papers, and an additional relevant article was found by 'snowballing'. A total of ten articles were considered relevant for this review. Most studies included patients with a sensitisation to Ara h 6 and cosensitisation to Ara h 2. Only three studies showed patients with a mono-sensitisation to Ara h 6. This illustrates that Ara h 6 mono-sensitisation has been neglected in literature. We present a case series of five children with sensitisation to peanut component Ara h 6. Only one of these five patients showed Ara h 8 cosensitivity. Three out of the five children had a positive double-blind placebo-controlled food challenge (DBPCFC), with moderate to strong reactions. CONCLUSION A mono-sensitisation to peanut component Ara h 6 is uncommon but can cause severe allergic reactions. Therefore, the determination of sIgE to Ara h 6 is warranted in patients with a suspected peanut allergy, especially in the absence of sensitisation to Ara h 1, 2, 3 and 9. WHAT IS KNOWN • Peanut allergy is common and can cause severe allergic reactions. • The diagnostics of peanut allergy has recently improved with the use of component resolved diagnosis What is new: • A mono-sensitisation to peanut component Ara h 6 is uncommon, but can cause severe allergic reactions • Determination of sIgE to Ara h 6 is warranted in patients with a suspected peanut allergy, especially in the absence of sensitisation to Ara h 1, 2, 3 and 9.
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Affiliation(s)
- J P M van der Valk
- Department of Internal Medicine, section of Allergology, Erasmus MC, Office Gk 323, P.O. box 2040, 3000CA, Rotterdam, The Netherlands.
| | - M W J Schreurs
- Department of Immunology, Laboratory Medical Immunology, Erasmus MC, Rotterdam, The Netherlands
| | - R El Bouch
- Department of Internal Medicine, section of Allergology, Erasmus MC, Office Gk 323, P.O. box 2040, 3000CA, Rotterdam, The Netherlands
| | - N J T Arends
- Department of Internal Medicine, section of Allergology, Erasmus MC, Office Gk 323, P.O. box 2040, 3000CA, Rotterdam, The Netherlands
- Department of Paediatric Allergology, Diaconessenhuis Voorburg, Reinier de Graaf Group, Delft, The Netherlands
| | - N W de Jong
- Department of Internal Medicine, section of Allergology, Erasmus MC, Office Gk 323, P.O. box 2040, 3000CA, Rotterdam, The Netherlands
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15
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van Erp FC, Klemans RJB, Meijer Y, van der Ent CK, Knulst AC. Using Component-Resolved Diagnostics in the Management of Peanut-Allergic Patients. CURRENT TREATMENT OPTIONS IN ALLERGY 2016; 3:169-180. [PMID: 27330930 PMCID: PMC4891380 DOI: 10.1007/s40521-016-0080-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Instead of relying on crude peanut extract, component-resolved diagnostics (CRD) uses sensitization to allergenic proteins within peanut. In this review, we describe the recent advances and future perspectives of the use of CRD in the management of peanut-allergic patients. There is strong evidence that sensitization to Ara h 2 is the best predictor for clinically relevant peanut allergy in children and adults. Isolated sensitization to other peanut components is only rarely present in patients with systemic reactions to peanut. It is, however, important to remark that cut-off points of sIgE to Ara h 2 that predict tolerance or allergy vary between different study populations, different age groups and geographical regions, and validation studies performed in different settings are necessary to implement cut-offs in daily practice. Future studies should focus on the role of CRD in risk-assessment early in life, predicting long-term tolerance and monitoring treatment responses following immunotherapy.
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Affiliation(s)
- F C van Erp
- Department of Paediatric Pulmonology and Allergology, University Medical Centre Utrecht, Utrecht, The Netherlands ; Department of Paediatric Pulmonology and Allergology, University Medical Center Utrecht, Wilhelmina Children's Hospital, P O Box 85090, 3508 AB Utrecht, The Netherlands
| | - R J B Klemans
- Department of Dermatology and Allergology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Y Meijer
- Department of Paediatric Pulmonology and Allergology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - C K van der Ent
- Department of Paediatric Pulmonology and Allergology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - A C Knulst
- Department of Dermatology and Allergology, University Medical Centre Utrecht, Utrecht, The Netherlands
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