Aggravation of airway inflammation and hypperresponsiveness following nasal challenge with dermatophagoides pteronyssinus in perennial allergic rhinitis patients without symptoms of asthma

Abstract

Background To investigate the changes in upper and lower airway inflammation and responsiveness following Dermatophagoides pteronyssinus (Der-p) nasal provocation test (NPT)  in Der-p sensitized rhinitis patients without asthmatic symptoms. Methods Study subjects included 15 non-asthmatic Der-p sensitized rhinitis (AR) patients with airway hyperresponsiveness (AHR) (AR+AHR+), 15 AR patients without AHR (AR+AHR-), 15 healthy control (HC) with Der-p sensitization (HC+DP+) and 15 HC without Der-p sensitization (HC+DP-). They underwent Der-p NPT. Nasal lavage and resistance, sputum induction, forced expiratory volume in 1 second (FEV₁) and airway responsiveness to histamine bronchoprovocation (PD₂₀-FEV₁) and exhaled nitric oxide (FeNO) were performed before and 6 hours after NPT. Number of eosinophils in nasal lavage fluid and induced sputum eosinophils were determined. Results The nasal airway resistance increased after NPT in subjects of all four groups  (P<0.05). FEV1 % predicted decreased in AR+AHR+ patients after NPT (P<0.05). Eosinophils in nasal lavage fluid and sputum increased significantly after NPT in AR+AHR+ and AR+AHR- patients (P<0.001). PD₂₀-FEV₁ was decreased and FeNO was increased significantly after NPT only in AR+AHR+ patients (P<0.05)，wherease, no significant changes were observed in HC+DP+ and HC+DP- subjects after NPT. The number of eosinophils from nasal lavage was strongly correlated with the sputum eosinophils, the level of FE_NO (r=0.737, p=0.000 and r=0.736, p=0.000), and was negatively correlated  with FEV₁ , PD₂₀ (r=-0.287, p=0.026 and r=-0.436, p=0.000). Conclusions  House dust mite nasal provocation test may induce upper and lower airway inflammation and hyperresponsiveness in patients with persistent allergic rhinitis without asthmatic symptoms.