Cypress allergen immunotherapy and pru p 7 sensitization

International audienceBackground: Up to 60% of food allergies in school children, adolescent and adults are related to an inhalant allergy. Sensitization to Pru p 7, the first identified allergenic gibberellin-regulated protein (GRP), is likely associated to primary sensitization to cypress pollen. Pru p 7 is a major allergen in peach-allergic Mediterranean patients, while other GRPs have been characterized in orange, Japanese apricot, cherry, and pomegranate. It is currently unknown whether cypress allergen immunotherapy (CUP AIT) is a risk factor for subsequent Pru p 7 sensitization and clinical expression as fruit allergy. The objective of this study was to analyze Pru p 7 sensitization as a function of CUP AIT in cypress allergic patients with or without fruit allergy.Method: Monocentric retrospective (January 2014 – December 2019) study of 391 outpatients ≥ 15 years attending one of the allergy departments in the University Hospitals of Marseille, France.Results: Pru p 7 sensitization was found in 27/39 (69%) cypress allergic patients with a history of CUP AIT and in 93/228 (41%) cypress allergic patients who had never received CUP AIT, P < 0.001. Fruit allergy was found in 30/39 (77%) of cypress-allergic patients who had received cypress allergen immunotherapy and in 126/228 (55%) of those who did not, P = 0.006. Among cypress allergic patients with confirmed allergy to fruit, Pru p 7 sensitization was found in 26/30 (87%) having received CUP AIT and in 72/126 (57%) who had never received CUP AIT, P = 0.003. CUP AIT was also associated with higher levels of IgE to Pru p 7 (median 2.02 vs 0.05, P < 0.001), especially in fruit allergic as compared to fruit tolerant patients (median 4.8 v. 0.18, P < 0.01). The difference was not imputable to patients’ age, cypress pollinosis duration, or time elapsed since the initiation of CUP AIT.Conclusion: Among patients with cypress pollinosis, CUP AIT was associated with higher occurrence of fruit allergy, higher prevalence and higher levels of Pru p 7 sensitization. However, the causal link cannot be inferred given the limitations of the retrospective design, including the absence of consistent data on Pru p 7 sensitization prior to CUP AIT initiation. We report a positive association between CUP AIT and the occurrence of fruit allergy and Pru p 7 sensitization. These results raise the question of CUP AIT ability to foster Pru p 7 sensitization and its clinical expression as fruit allergy