Nasal Obstruction in Patients with Seasonal Allergic Rhinitis: Relationships between Allergic Inflammation and Nasal Airflow

Abstract

Background: Nasal obstruction is a typical symptom of allergic rhinitis. Allergic rhinitis is characterized by a Th2-dependent inflammation. The aim of this study was to evaluate the possible relationships between allergic inflammation, including inflammatory cells and cytokine pattern, and nasal airflow in patients with nasal obstruction due to seasonal allergic rhinitis. Methods: Fifty patients (31 males and 19 females, mean age 31.9 ± 4.8 years) with seasonal allergic rhinitis were evaluated during the pollen season. All of them had moderate to severe nasal obstruction. Total symptom score, rhinomanometry, nasal lavage, and nasal scraping were assessed in all subjects. Inflammatory cells were counted by conventional staining; IL-4, IL-5, IL-8, and IFNγ were measured by immunoassay on fluids recovered from nasal lavage. Results: Significant positive relationships were demonstrated between eosinophil infiltration and IL-4 levels (p < 0.0001), eosinophils and IL-5 levels (p < 0.0001), and eosinophils and IL-8 levels (p < 0.0001). Significant negative relationships were demonstrated between eosinophil infiltration and IFNγ levels (p < 0.0001) and eosinophil infiltration and nasal airflow (p < 0.001). Conclusions: This study demonstrates the close connection between Th2 cytokines and eosinophil infiltration. In addition, there is clear evidence concerning the relationship between eosinophil infiltration and nasal airflow. These findings constitute first evidence of the relationship between nasal airflow impairment and Th2-related inflammation in seasonal allergic rhinitis.