Two nonspecific lipid transfer proteins (nsLTPs) from tomato seeds are associated to severe symptoms of tomato-allergic patients

Scope: Tomato has become one of the most consumed vegetables worldwide, but its intake is often accompanied by an increasing risk of inducing allergic symptoms. The aim of the work was the identification of new seed-specific allergens associated with severe symptoms in patients allergic to this edible vegetable. Methods and results: We used 22 sera from well-defined tomato-allergic patients. Tomato seed proteins were purified and analyzed for biochemical and immunological characterization. A mixture of two associated IgE-binding nsLTPs was purified from tomato seeds. Both allergens, Sola vertical bar 7 and Sola vertical bar 6, displayed primary structure differences with respect to their counterpart, Sola vertical bar 3, from tomato pulp/peel. They retained the ability to bind IgE from 71.4% of patients with severe symptoms. The purified proteins induced positive basophil activation test and skin prick test, and displayed cross-reactivity with homologous allergens from peanut and sunflower seeds, among others. Conclusion: We herein described two novel allergens from tomato seeds that belong to the nonspecific lipid transfer protein family classes 1 and 2, respectively. This is the first work associating IgE reactivity to these proteins with severe symptoms of certain tomato-allergic patients. Therefore, they are optimal candidates for clarifying the diagnosis of the tomato allergy.