Validity and reproducibility of morphologic analysis of nasal secretions obtained using ultrasonic nebulization of hypertonic solution

Background: Collection of nasal secretions is important for the evaluation of upper airways inflammation in many nasal disorders. Objective: To study the validity and reproducibility of nasal secretion cellularity induced by nebulization of hypertonic solution in patients with allergic rhinitis (AR), patients with nonallergic rhinitis with eosinophilia syndrome (NARES), and control subjects. Methods: Sixty-eight individuals (29 with AR [mean +/- SD age, 33.3 +/- 16.9 years], 23 with NARES [mean SD age, 46.4 +/- 16.6 years], and 16 controls [mean +/- SD age, 42.1 +/- 15.1 years]) underwent ultrasonic nebulization of hypertonic (4.5%) saline solution on 2 different occasions to study the validity and reproducibility of total and differential cell counts of nasal secretions. Results: The mean SD percentage of eosinophils was significantly higher in samples from patients with AR (20.8% +/- 23.1%) and NARES (18.7% +/- 22.8%) than in samples from controls (0.6% +/- 0.6%; P <.001 for both). There was a significant correlation between 2 samples of nasal secretions obtained on 2 different occasions for percentages of macrophages, neutrophils, eosinophils, and epithelial cells. Conclusions: The analysis of nasal secretions obtained using ultrasonic nebulization of hypertonic solution can distinguish patients with AR and NARES from controls. The reproducibility of this technique is good for macrophages, neutrophils, eosinophils, and epithelial cells. This method could be used to detect nasal airway inflammation in clinical settings.