Recombinant Bet v 1, the major birch pollen allergen, induces hypersensitivity reactions equal to those induced by natural Bet v 1 in the airways of patients allergic to tree pollen

Background: Atopic allergens produced by recombinant DNA methods are promising tools for diagnosis and therapy of Type I allergy. To evaluate the immunologic properties of these molecules, it is necessary to compare them with natural allergens in vitro and in vivo. Objective: The study was carried out to determine whether the potency of recombinant Bet v 1 (rBet v 1) is comparable to that of natural Bet v 1 (nBet v 1) in inducing allergic reactions in the nose and bronchi. Methods: Thirteen patients allergic to birch pollen with bronchial asthma and/or rhinitis were investigated. Skin prick tests and nasal and bronchial challenges were performed with rBet v 1 and nBet v 1. Results: In patients allergic to birch pollen, both allergens induced comparable skin reactions. In subjects with rhinitis rBet v 1 was equally potent in inducing nasal reactions (mean PD +60NR ± SD, 10.48 ± 17.42 μg vs 7.98  ± 8.9 μg, p > 0.05). In patients with asthma, rBet v 1 was equally potent in inducing bronchial reactions (PD 20FEV 1, 0.81 ± 1.74 μg vs 0.62  ± 1.44 μg, p > 0.05) as nBet v 1. Conclusion: No significant differences were observed between natural and recombinant allergen. We conclude that allergens produced by recombinant techniques can induce typical allergic reactions in important target organs of Type I allergy: the nose and bronchi. (J Allergy Clin Immunol 1997;99:354-9.)