Functional analysis of cross-reactive immunoglobulin E antibodies: peanut-specific immunoglobulin E sensitizes basophils to tree nut allergens.
Clin Exp Allergy
; 35(8): 1056-64, 2005 Aug.
Article
em En
| MEDLINE
| ID: mdl-16120088
ABSTRACT
BACKGROUND:
Peanut and tree nuts are a major cause of food-induced anaphylaxis with an appreciable mortality. Co-sensitization to peanuts and tree nuts is a common clinical observation and may be because of peanut-specific serum IgE antibodies that cross-react with tree nut allergens. It is, however, unclear whether these cross-reactive IgE antibodies are involved in effector-cell activation.OBJECTIVE:
To determine if cross-reactivity of peanut-specific IgE antibodies with tree nuts can cause effector cell activation using an in vitro basophil activation assay.METHODS:
Two peanut allergic subjects with positive specific IgE for peanut and tree nuts (as measured by CAP-FEIA) were studied. Basophil activation to peanut and tree nuts, as indicated by CD63 expression, was assessed by flow cytometry to confirm co-sensitization to peanut and tree nuts. Inhibition ELISA using sera from the subjects was performed to detect peanut-specific IgE antibodies that cross-reacted with tree nut proteins. To determine whether cross-reactive tree nut allergens can induce effector-cell activation, peanut-specific antibodies were affinity purified from the subject sera and used to resensitize non-peanut/tree nut allergic donor basophils stripped of surface IgE. Basophil activation was then measured following stimulation with peanut and tree nut extracts.RESULTS:
The two peanut allergic subjects in this study showed positive basophil activation to the peanut and tree nut extracts. Inhibition ELISA demonstrated that pre-incubation of the peanut allergic subject sera with almond, Brazil nut and hazelnut extracts inhibited IgE binding to peanut extract. IgE-stripped basophils from non-peanut/tree nut allergic subjects resensitized with affinity-purified peanut-specific antibodies from the peanut allergic subject sera became activated following stimulation with peanut, almond and Brazil nut extracts, demonstrating biological activity of cross-reactive IgE antibodies.CONCLUSION:
Peanut-specific IgE antibodies that cross-react with tree nut allergens can cause effector-cell activation and may contribute to the manifestation of tree nut allergy in peanut allergic subjects.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arachis
/
Basófilos
/
Imunoglobulina E
/
Alérgenos
/
Hipersensibilidade a Amendoim
/
Nozes
Limite:
Adolescent
/
Adult
/
Female
/
Humans
/
Middle aged
Idioma:
En
Revista:
Clin Exp Allergy
Assunto da revista:
ALERGIA E IMUNOLOGIA
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Austrália