Effect of fluticasone propionate aqueous nasal spray on allergen-induced inflammatory changes in the nasal airways of allergic rhinitics following exposure to nitrogen dioxide.

The authors have recently demonstrated that prior exposure for 6 h to 400 p.p.b. nitrogen dioxide significantly enhances the early phase response of eosinophils in the nasal airways of allergic rhinitics to subsequent allergen provocation. To investigate whether treatment with fluticasone propionate aqueous nasal spray (FP) can alter the inflammatory response in the nasal airways under these conditions. Sixteen allergic, rhinitic patients were recruited for this double-blind, randomized, cross-over study and received either topical FP 200 microg once daily or matched placebo for 4 weeks. At the end of treatment, all underwent nasal lavage followed by a 6 h exposure to 400 p.p.b. NO2. Following exposure to NO2, nasal allergen challenge was performed and nasal lavage repeated. After a 4 week washout period, patients were given alternate treatment and tested as above. Analysis of eosinophil cationic protein (ECP) in lavage samples from patients treated with placebo, demonstrated that this was significantly increased from a median value of 2.3 ng/mL (range: 1.0-7.1) to 15.1 ng/mL (range: 1.5-40.0; P = 0.001) following exposure to NO2 and allergen challenge. However, in patients treated with FP, ECP concentrations only increased from 3.3 ng/mL (range: 0.2-9.2) to 5.1 ng/mL (range: 0.3-20.0; P = 0.034) following exposure to NO2 and allergen challenge. The difference of the changes in ECP concentration between the placebo and the FP-treated group was significant (P = 0.003). Similarly, there was a significant increase in the number of eosinophils in nasal lavage after exposure to NO2 and allergen challenge in the placebo group, and this increase was inhibited in FP group (P = 0.002). These results suggest that FP influences NO2- and allergen-induced changes in eosinophil function, as well as eosinophil number in the nasal airway of allergic rhinitics.