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 betwee n 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 undertak en to determine whether the EPR, LPR, and nasal hyperreactivity are re lated in perennial allergic rhinitis. Methods - Twenty four patients w ith rhinitis who were allergic to house dust mite (HDM) were challenge d with HDM extract. The nasal response was monitored by symptom scores and nasal lavages for up to 9.5 hours after challenge and concentrati ons of albumin, tryptase, and eosinophil cationic protein (ECP) in the lavage fluid were measured. Thirteen patients (defined as dual respon ders) had increased symptom scores between 3.5 and 9.5 hours compared with the baseline score. The other 11 patients (defined as early respo nders) showed an isolated EPR only. Nasal hyperreactivity was determin ed by nasal histamine challenge 24 hours later. Results - Dual respond ers showed a significantly higher symptom score, albumin influx, and t ryptase 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 g roup. Dual responders showed a significantly stronger response to all doses of histamine. The area under the curve (AUG) of symptom scores d uring EPR and LPR and the AUC of the histamine dose response were sign ificantly 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 wi th perennial allergic rhinitis the nasal responses to allergen and his tamine are associated. Dual responders have an increased EPR, increase d levels of mediators, and increased allergen-induced hyperreactivity.