Serological characterization of allergens in poppy seeds

Background ann objective Poppy seeds in food can induce immediate-type alle rgic reactions ranging from mild local symptoms to severe anaphylactic reac tions. Previous publications showed that poppy seeds cross-react with other plant-derived allergens. The IgE-binding components have not been defined so far. Methods We analysed sera from 11 patients with adverse reactions after inge stion of poppy seed-containing food by IgE-immunoblotting. Nine of 11 patie nts showed concomitant IgE binding to allergens of birch, mugwort or grass pollen in PAST-CAP, and suffered from characteristic seasonal symptoms. Results Ten of 11 patients showed IgE binding to a 45-kDa protein, 4/11 to a 34-kDa, 5/11 to a 17-kDa, 5/11 to a 14-kDa, and 3/11 to a 5-kDa component . Furthermore, individual IgE binding to proteins of 20, 25, 30 and 40 kDa proteins could be observed. Periodate treatment of blots markedly reduced t he IgE binding capacity of the 40- and 45-kDa compounds, indicating the exi stence of IgE epitopes of the carbohydrate type. Inhibition studies indicat ed the presence of homologues of pollen allergens in extracts from poppy se eds, i.e. Bet v 1 and Bet v 2. Conclusion The serological analysis showed IgE binding to protein and sugar components of poppy seeds. The 40- and 45-kDa allergens are glycoproteins and contain IgE binding carbohydrate moieties. Moreover, cross-reacting hom ologues of pollen allergens including Bet v 1 and profilin were detected in poppy seed extract.