Nasal responsiveness to allergen and histamine in patients with perennial rhinitis with and without a late phase response

Background - In the lower airways an association has been found between early phase reaction (EPR), late phase reaction (LPR), and bronchial hyperreactivity. However, this association has not been shown for the upper airways in nasal pollen challenge studies. A study was undertaken to determine whether the EPR, LPR, and nasal hyperreactivity are related in perennial allergic rhinitis. Methods - Twenty four patients with rhinitis who were allergic to house dust mite (HDM) were challenged with HDM extract. The nasal response was monitored by symptom scores and nasal lavages for up to 9.5 hours after challenge and concentrations of albumin, tryptase, and eosinophil cationic protein (ECP) in the lavage fluid were measured. Thirteen patients (defined as dual responders) had increased symptom scores between 3.5 and 9.5 hours compared with the baseline score. The other 11 patients (defined as early responders) showed an isolated EPR only. Nasal hyperreactivity was determined by nasal histamine challenge 24 hours later. Results - Dual responders showed a significantly higher symptom score, albumin influx, and tryptase release during the EPR. During the late phase (3.5-9.5 hours) albumin influx was significantly increased at most time points and ECP release was significantly higher at 9.5 hours in the dual responder group. Dual responders showed a significantly stronger response to all doses of histamine. The area under the curve (AUG) of symptom scores during EPR and LPR and the AUC of the histamine dose response were significantly correlated (EPR-LPR: r=0.49, p<0.01; EPR-histamine: r=0.75, p<0.001; LPR-histamine: r=0.66, p<0.001). Conclusions - In patients with perennial allergic rhinitis the nasal responses to allergen and histamine are associated. Dual responders have an increased EPR, increased levels of mediators, and increased allergen-induced hyperreactivity.