The response to nasal allergen provocation with grass pollen is reduced inpatients with chronic rhinosinusitis with nasal polyposis and grass sensitization

BackgroundThe majority of grass pollen-sensitized rhinitis patients develops allergic symptoms when exposed to the causal allergen and shows a positive nasal allergen provocation test (NAPT). Chronic rhinosinusitis with nasal polyposis (CRSwNP) patients, also characterized by eosinophilic inflammation and local IgE production, can suffer from comorbid inhalant allergy, but may show a different response to allergens. ObjectiveWe aimed to explore the allergic response to grass pollen allergens by NAPT in grass pollen-sensitized CRSwNP patients. MethodsTwelve grass pollen-sensitized CRSwNP patients underwent NAPT with grass pollen and were compared with 12 grass pollen allergic rhinitis patients, 12 control patients and 12 CRSwNP patients without grass pollen sensitization. A positive NAPT was based on change in nasal airflow and symptoms. Further, VAS scores of different symptoms were noted before and after NAPT. Biomarkers such as total IgE, grass pollen-specific IgE and tryptase were measured in serum and nasal secretions. ResultsNAPT was positive in 6 of 12 of the grass pollen-sensitized CRSwNP patients, and another four patients developed allergic symptoms not fulfilling the criteria of positivity. In contrast, all patients with allergic rhinitis developed a positive provocation test, whereas in the control group one of the patients and in the non-sensitized CRSwNP group two of the patients developed a positive provocation test. Conclusion and clinical relevanceThese results show that allergen exposure induces an attenuated clinical response in patients with CRSwNP and sensitization to grass pollen as compared with grass pollen allergic rhinitis patients.