Relationship between Bet v 1 and Bet v 2 specific IgE and food allergy in children with grass pollen respiratory allergy.

Grass allergy is the most common pollinosis in Northern Italy. Some patients with grass allergy show polysensitization against other pollens and plant-derived foods. In these patients oral allergic syndrome (OAS) is frequently associated. To evaluate the correlation between food allergy or food sensitization and specific IgE against panallergens such as Bet v 1 and Bet v 2, we studied 56 children (mean age: 8 years 5 months) suffering from respiratory allergy due to grass pollens were enrolled. Specific IgE against the most important food, inhalant allergen and Bet v 1, Bet v 2 were performed by ImmunoCAP technology (UniCAP 1000, Pharmacia Diagnostics, Uppsala, Sweden). We found 14 children (25%) sensitized to Bet v 1 and 13 (23%) to Bet v 2; in 24 cases (42.3%) a sensitization to at least one of the 2 panallergens was observed. Five of the 14 cases (36%) sensitized to Bet v 1 showed food allergy and 8 (57%) food sensitization; 6 (46%) of the 13 children sensitized to Bet v 2 showed food allergy and 7 (54%) food sensitization; only one case of Bet v 1 specific IgE without food allergy or sensitization was seen. Sixteen subjects (29%) showed food allergy (group A); 20 children (35.5%) multiple sensitizations to inhalant and at least one plant-derived food (group B); 20 subjects (35.5%) only inhalant allergens (group C). Sensitization to Bet v 1 (P<0.03) and Bet v 2 (P<0.009) is from a statistical point of view significantly higher in groups A and B than in group C. In the 16 patients with food allergy hazelnut was the major triggering food (50%), followed by peanut (38%), kiwi (31%), apple and walnut (19%). Specific IgE for Bet v 1 is more associated with nuts and legumes, while Bet v 2 is more related to fresh fruit and vegetables. In conclusion grass pollinosis is frequently associated with polysensitization to other pollen and food allergens. Bet v 1 and Bet v 2 specific IgE are significantly higher in these patients than in patients with grass monosensitization, and this sensitization may be considered a possible risk factors to evolve later into food allergy. Among the offending foods, legumes and the nut group are mostly related to Bet v 1, while vegetables and fresh fruits to Bet v 2.