Background: Birch pollinosis is often accompanied by allergy to fruits such as peach and apple. Bet v I is of major importance as cross-reactive allergen for this combined allergy. We studied a group of patients with combined grass pollinosis and fruit allergy from an area virtually without birch trees.
Objective: The aim of this study was to investigate the possible involvement of profilin and carbohydrate groups as cross-reactive structures in pollen and fruits.
Methods: RAST inhibition was performed to measure cross-reactive IgE to pollen and fruits. The presence of IgE against profilin was determined in a RAST with purified grass profilin, and IgE against carbohydrate structures was determined in a RAST with proteinase K-digested grass pollen extract. The biologic activity of IgE in response to profilin was tested by in vitro histamine release and skin prick tests.
Results: IgE against fruits was shown to be largely cross-reactive with grass pollen. The majority of the patients had IgE against profilin (12 of 16) and carbohydrate structures (9 of 10). Profilin was shown to have biologic activity, in both histamine release and skin prick tests.
Conclusion: Profilin is an important allergen for patients with combined grass pollen/fruit allergy in areas without birch trees.