Title
Relevance of Ara h1, Ara h2 and Ara h3 in peanut-allergic patients, as determined by immunoglobulin E Western blotting, basophil-histamine release and intracutaneous testing: Ara h2 is the most important peanut allergen
Author
Koppelman, S.J.
Wensing, M.
Ertmann, M.
Knulst, A.C.
Knol, E.F.
TNO Voeding
Publication year
2004
Abstract
Background: A number of allergenic proteins in peanut has been described and the relative importance of these allergens is yet to be determined. Objectives: We have investigated the relevance of previously identified peanut allergens in well-characterized peanut-allergic patients by in vitro, ex vivo and in vivo assays. Methods: Thirty-two adult peanut-allergic patients were included based on careful and standardized patient history and the presence of peanut-specific IgE. The diagnosis peanut allergy was confirmed using double-blind placebo-controlled food challenges in 23 patients. Major peanut allergens Ara h1, Ara h2 and Ara h3 were purified from peanuts using ion-exchange chromatography. IgE immunoblotting was performed and IgE-cross-linking capacity was examined by measuring histamine release (HR) after incubating patient basophils as well as passively sensitized basophils with several dilutions of the allergens. Intracutaneous tests (ICTs) using 10-fold dilution steps of the purified allergens and crude peanut extract were performed. Results: Ara h2 was recognized most frequently (26 out of 32) in all tests and induced both positive skin tests and basophil degranulation at low concentrations, whereas Ara h1 and Ara h3 were recognized less frequently and reacted only at 100-fold higher concentrations as analysed with HR and intracutaneous testing (ICT). Next to the three tested allergens, proteins with molecular weights of somewhat smaller than 15 kDa were identified as a IgE-binding proteins on immunoblot in the majority of the patients (20 out of 32). Conclusion: We conclude that Ara h2 is, for our patient group, the most important peanut allergen, and that previously unidentified peanut proteins with molecular weights of somewhat smaller than 15 kDa may be important allergens as well. ICT in combination with basophil-HR and IgE immunoblotting provides insight in the patient specificity towards the individual peanut allergens.
Subject
Nutrition
Food technology
Allergens
Ara h1
Ara h2
Ara h3
Basophils
Histamine release
Immunoblot
Peanut
Purification
Skin test
allergen
binding protein
histamine
immunoglobulin E
placebo
plant extract
adolescent
adult
aged
anamnesis
antigen purification
article
basophil degranulation
clinical article
concentration (parameters)
controlled study
cross linking
diagnostic procedure
dilution
ex vivo study
female
histamine release
human
immunoblotting
in vitro study
in vivo culture
intracutaneous test
ion exchange chromatography
male
molecular weight
pathogenesis
peanut allergy
priority journal
provocation test
skin test
standardization
Western blotting
Adolescent
Adult
Allergens
Antibody Specificity
Arachis hypogaea
Basophils
Blotting, Western
Dose-Response Relationship, Immunologic
Female
Food Hypersensitivity
Glycoproteins
Histamine Release
Humans
Immunoglobulin E
Male
Plant Proteins
Skin Tests
To reference this document use:
http://resolver.tudelft.nl/uuid:e6e2bad7-4178-4f8c-9f61-c87d282928f7
DOI
https://doi.org/10.1111/j.1365-2222.2004.1923.x
TNO identifier
237673
ISSN
0954-7894
Source
Clinical and Experimental Allergy, 34 (4), 583-590
Document type
article