Nasal Eosinophilia can Predict Bronchial Hyperresponsiveness in Persistent Rhinitis: Evidence for United Airways Disease Concept

Abstract

Background Nasal eosinophils may be indicative of bronchial hyperresponsiveness (BHR) in rhinitis concerning the “united airways disease” theory. This study was designed to evaluate the relationship between nasal eosinophilia and BHR in persistent perennial rhinitis patients. Methods Thirty-seven patients (12 males and 25 females, mean age: 33.3 ± 10.4 years) were included in the study. Skin-prick test, nasal symptom score, nasal smears, methacholine bronchial challenge test, and nasal rhinometry were obtained in all patients. Eosinophil count in nasal smears was expressed as a percentage of the total cells. None of the patients had asthma. Results There was no difference between the number of atopic and nonatopic patients having BHR (4/20 versus 4/17; chi-squared = 0.07; p > 0.05). Total nasal flow was lower and percentage of nasal eosinophils was higher in the patients with BHR than in patients without BHR (p = 0.012 and p = 0.009, respectively). A cutoff point of 68% nasal eosinophils yielded a sensitivity of 100% (63.1–100) and a specificity of 58.6% (38.9–76.5) to determine the presence of BHR. Positive likelihood ratio for the value of eosinophils above cutoff value was 2.42 (1.8–3.3). Conclusion This study shows the relationship between nasal eosinophils and BHR in persistent perennial rhinitis patients. Nasal eosinophil percentage below cutoff value indicates that a patient does not have BHR.