Background: Oral allergy syndrome in response to fruits and vegetables frequently occurs as clusters of hypersensitivity to members of the same botanical family, for which the immunologic basis lies in a number of common allergens, most of them still unidentified.
Objective: This study was designed to assess the in vivo and in vitro cross-reactivity between fruits of the Prunoideae subfamily (i.e., peach, cherry, apricot, and plum) and to identify their major allergens and the cross-reactivity of the peach extract with grass and birch pollen.
Methods: The in vivo study was conducted by skin prick tests and open food challenges with fresh fruits in 23 patients with oral allergy syndrome for peach and positive skin prick test and RAST results for the other Prunoideae. In vitro sodium dodecylsulfate-polyacrylamide gel electrophoresis was followed by immunoblotting and immunoblotting-inhibition.
Results: A 13 kd component was identified as the only major allergen common to all the Prunoideae, the other major allergens were found at 14 kd in peach and at 30 kd in cherry. Immunoblotting inhibition showed wide cross-reactivity within the Prunoideae, whereas grass and birch pollen partially inhibited the peach blotting.
Conclusions: Clinical cross-reactivity to Prunoideae is essentially due to a common 13 kd IgE-binding component, which seems to be the most important major allergen of this subfamily, not shared with grass and birch pollen.