Value of small airway function and sputum eosinophils number monitoring in children with cough variant asthma at remission period

Abstract

Objective To investigate the value of small airway function and sputum eosinophils number monitoring in children with cough variant asthma at remission period. Methods Pulmonary function parameters and induced sputum samples from 52 children with cough variant asthma at remission period were collected.The indicators of small airway function included forced expiratory flow after 25%, 50% and 75%(MEF25, MEF50 and MEF75) were recorded.Sputum eosinophils number was measured.Sixteen healthy children were taken as control group. Results Small airway function was impaired in different degrees in the children with cough variant asthma at remission period.The MEF50 of the cough variant asthma patients were much lower than that of control group(P<0.01). Compared with control group, the sputum eosinophils numbers in children with cough variant asthma at remission period were much higher (P<0.01). The damages of small airway function were significant in recurrent frequency≥3 times/year than that of those <3 times/year.Children associated both with MEF50 less than 80% and sputum eosinophils numbers ≥4% were more easy to relapse. Conclusion Monitoring both of small airway function and sputum eosinophils number is important in children with cough variant asthma at remission period. Key words: Small airway function; Sputum eosinophils; Cough variant asthma