ALLERGY TO PISTACHIO - CROSS-REACTIVITY BETWEEN PISTACHIO NUT AND OTHER ANACARDIACEAE

Background Anaphylaxis against Anacardiaceae nuts is uncommon and the allergens involved still poorly characterized. For this reason two pat ients with allergy towards pistachio nut (a member of the Anacardiacea e family) have been studied. Objective Identification of immunoallerge ns present in pistachio nut and analysis of crossreactive antigens in other members of the same plant family, specifically cashew and mango. Methods Presence of specific IgE for pistachio and cashew nut and for mango seed and pulp was determined by skin tests and radioallergosorb ent assay (RAST). The allergenic profile of pistachio and cashew was a nalysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis ( SDS-PAGE) followed by immunoblotting. Crossreactivity between pistachi o and the other Anacardiaceae was studied by RAST inhibition. Results Skin tests were positive for pistachio and cashew in the two children and for mango seed in one. PAST was positive for pistachio and cashew in both patients. On immunoblotting, serum from both patients recogniz ed several pistachio and cashew allergens with a molecular weight rang ing from < 14.2-70 kDa. PAST inhibition demonstrated common antigenic determinants between pistachio and cashew nut. Crossreactivity was als o found between pistachio nut and mango seed but not with mango pulp. Conclusion Pistachio nut contains several protein allergens able to tr igger type I hypersensitivity reactions. These allergens can be found also in cashew nut and mango seed but not in mango pulp.