Tomato allergy in children and young adults: cross-reactivity with latex and potato

Background: Several studies have shown that allergy to natural rubber latex is associated with cross-reactivity to certain foods such as tomato and po tato. The objective was to investigate the clinical and immunologic differe nces between a group of patients with clinical allergy to tomato and latex and another which had only clinical allergy to tomato. We also aimed to ass ess, in vitro, the relationship of tomato and latex allergens. which could explain the cross-reactivity. Methods: Forty patients with histories of adverse reactions to tomato and I gE-mediated hypersensitivity were enrolled in the study. Tomato, latex, and potato components were analyzed by SDS-PAGE immunoblotting. CAP and immuno blot inhibition were used to study allergen cross-reactivity. Results: Patients from group A had a mean age of 13.2 years. and in group B the mean age was 21.7 years, In group B, 9/10 patients belonged to the lat ex-fruits syndrome. All patients of both groups tolerated potato. Immunoblo tting patterns obtained with patients' sera from pool A showed IgE-binding bands to tomato ranging from 44 to 46 kDa and a triple band at 67 kDa. For latex, there was a strong binding at 44 kDa, and potato showed a strong ban d of 44 kDa and a 67-kDa triple band. In pool B, the binding to the band of 44 kDa in latex and tomato was more intense than in pool A. In pool A. imm unoblot inhibition with potato allergen showed an intense inhibition of the three allergens (potato, latex. and tomato), with latex, inhibition was pa rtial and with tomato, a complete inhibition of tomato and latex was observ ed. and a partial inhibition of potato. In pool B, the inhibition pattern f ollowed a similar tendency to pool A. The CAP inhibition confirmed the high rate of cross-reactivity between tomato, potato, and latex. Conclusions: In our study, tomato, potato, and latex showed a common band o f 44-46 kDa probably corresponding to patatin. This protein could be implic ated in the high cross-reactivity between tomato, latex. and potato observe d in the immunoblot and CAP inhibition.