Relationships between allergic inflammation and nasal airflow in children with seasonal allergic rhinitis.

BACKGROUND: Allergic rhinitis is characterized by a T(H)2-dependent inflammation. Nasal obstruction is a typical symptom of allergic rhinitis. OBJECTIVE: To evaluate the possible relationships among nasal symptoms, allergic inflammation, including inflammatory cells and cytokine pattern, and nasal airflow in children with seasonal allergic rhinitis. METHODS: Children with seasonal allergic rhinitis and moderate-severe nasal obstruction were evaluated during the pollen season. Total symptom score, rhinomanometry, nasal lavage, and nasal scraping were evaluated in all patients. Inflammatory cells were counted by conventional staining; interleukin 5 (IL-5) and IL-8 levels were measured by immunoassay on fluids recovered from nasal lavage. RESULTS: Twenty children (11 boys and 9 girls; mean +/- SD age, 12.9 +/- 1.7 years) participated in this study. Eosinophil levels were significantly associated with total symptom score (r = 90.6%, P < .001), IL-5 (r = 94.9%, P < .001), and nasal flow (r = -93.6%, P < .001). No association was elicited with IL-8 (r = 9.4%, P = .69). In a multivariate analysis that included eosinophils, neutrophils, and IL-5, eosinophil levels were shown to be the only independent predictor of nasal flow. CONCLUSIONS: This study demonstrates the close connection between T(H)2 cytokines and eosinophil infiltration. In addition, there is clear evidence concerning the relationship among nasal symptoms, eosinophil infiltration, and nasal airflow. These findings constitute evidence of the relationship between nasal airflow impairment and eosinophilic inflammation in children with seasonal allergic rhinitis.