Rye gamma-70 and gamma-35 secalins and barley gamma-3 hordein cross-react with omega-5 gliadin, a major allergen in wheat-dependent, exercise-induced anaphylaxis.
Patients with wheat-dependent, exercise-induced anaphylaxis experience severe allergic reactions when exercising after ingestion of wheat. The major wheat allergen associated with these reactions is a omega-5 gliadin, and patients following a gluten-free diet have remained free of symptoms. The aim of this study was to examine whether allergens cross-reacting with wheat omega-5 gliadin are present in rye, barley and oats. Sera from 23 adult patients with wheat-dependent, exercise-induced anaphylaxis were examined. Cereal allergens cross-reacting with wheat omega-5 gliadin were identified by immunoblot inhibition. The cross-reactive allergens were purified by gel filtration and reversed-phase chromatography and submitted to amino acid sequencing. Cross-reactivity was further studied by IgE ELISA and ELISA inhibition, and in vivo reactivity by skin prick testing. In immunoblotting rabbit anti-omega-5 gliadin antibodies bound to 70 kDa and 32 kDa proteins in rye and a 34-kDa protein in barley, but not to proteins in oats. N-terminal sequencing identified these proteins as rye gamma-70 secalin, rye gamma- 35 secalin and barley gamma-3 hordein, correspondingly. In ELISA 21/23 (91%) patients with wheat-dependent, exercise-induced anaphylaxis showed IgE antibodies to purified gamma-70 secalin, 19/23 (83%) to gamma-35 secalin and 21/23 (91%) to gamma-3 hordein. In ELISA inhibition omega-5 gliadin inhibited over 90% of the IgE binding of pooled patient sera to solid-phase gamma-secalins and gamma-3 hordein. Skin prick testing gave positive reactions to gamma-70 secalin in 10/15 (67%) patients, to gamma-35 secalin in 3/15 (20%) patients and to gamma-3 hordein in 7/15 (47%) patients. The results of this study show that gamma-70 and gamma-35 secalins in rye and gamma-3 hordein in barley cross-react with omega-5 gliadin, a major allergen in wheat-dependent, exercise-induced anaphylaxis. These findings suggest that also rye and barley may elicit symptoms in patients with wheat-dependent, exercise-induced anaphylaxis.
Department of Dermatology, University of Helsinki and Hospital for Skin and Allergic Diseases, Helsinki, Finland.
K
K
Palosuo
H
H
Alenius
E
E
Varjonen
N
N
Kalkkinen
T
T
Reunala
D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology*; D000707:Anaphylaxis / Q000276:immunology*; D003429:Cross Reactions; D005260:Female; D005512:Food Hypersensitivity; D005903:Gliadin / Q000276:immunology*; D005983:Glutens; D001467:Hordeum / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010940:Plant Proteins / Q000276:immunology*; D012434:Secale / Q000276:immunology; D014908:Triticum / Q000276:immunology
D000485:Allergens; D010940:Plant Proteins; D005983:Glutens; D005903:Gliadin