Detection of 20 kDa and 32 kDa IgE-binding proteins as the major allergens in Italian sesame seed allergic patients

R. Asero, L. Cecchi, M. Cervone, M. Crivellaro, F. Lodi Rizzini, V. Pravettoni, O. Quercia, S. Amato, G. Mistrello

Background and objective. Sesame seed allergy, a potentially very severe food allergy, seems on the rise worldwide but is still uncommon in Italy. The aim of the present study was to investigate the allergenic profile of Italian sesame seed-allergic patients. Methods. Patients with genuine sesame seed allergy diagnosed over one year in a large number of allergy centers scattered through Italy were considered for the study. Their IgE reactivity to sesame seed allergens was characterized by immunoblot analysis. Results. Eleven sesame seed allergic patients were detected and studied. 10/10 patients showed IgE reactivity against a sesame allergen at about 20 kDa, and 7/10 showed an extremely strong reactivity at about 32 kDa. The same 7 sera reacted also against a 28 kDa allergen, although such reactivity was significantly weaker in 6/7 cases. Eight patients showed IgE reactivity at about 48 kDa, and 5 sera reacted against higher m.w. proteins at about 67 kDa. Two sera showed IgE reactivity at about 43 kDa as well. Only one serum appeared to react to 2S-albumin. Conclusions. Italian sesame seed-allergic patients react mostly against allergens other than those described so far as major ones.
A large number of recombinant sesame allergens will be needed for a comprehensive component-resolved diagnosis of allergy to this food.
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