Lower Airway Inflammation in Nonasthmatic Allergic Rhinitis Patients

Objective: Allergic rhinitis and asthma have been considered as a single airway disease sharing a common pathophysiological mechanism of airway inflammation. We aimed to investigate the lower airway inflammation in allergic rhinitis patients without asthma. Material and Methods: Forty patients who referred to our tertiary care hospital's otorhinolaryngology clinic and diagnosed as moderate/severe persistent allergic rhinitis according to ARIA criteria were included in the study. After evaluation for the eligibility for the study, a nasal smear was taken, and rhinomanometry was performed to measure the nasal obstruction on visit 1. Twenty-four hours later from the visit 1, pulmonary functions including bronchial hyperactivity (BHR) were measured on visit 2. Twenty-four hours later from the visit 2, sputum induction was performed, and cell distribution of the sputums was evaluated. Results: Mean age of the 17 male and 23 female patients was 37 +/- 11. Nasal smear eosinophilia was studied in 36 of the patients and found positive in 36%. Nasal obstruction was demonstrated in 68% of the patients by rhinomanometry. BHR was positive in 30% of the participants. There was not any statistical significant relationship between nasal eosinophilia and nasal obstruction severity, BHR and induced sputum eosinophilia (p> 0.05). Among the induced sputums which were of good quality to be evaluated, 7.5% had an eosinophil ratio of 2%. Any relationship between induced sputum eosinophil percentages and FEV1, FEV1/FVC, nasal obstruction severity was not observed (p> 0.05). However, BHR was found to be significantly related with FEV1/FVC ratio which was >70% through the whole study population (r= 0.392 p= 0.012). Condusion: We could not demonstrate the expected relationship between nasal and lower airway inflammation markers in our study group of allergic rhinitis patients. This may be due to the small number of study population and strict exclusion of asthmatic patients as well as particularly the difficulties in standardization of the induced sputum technique.