Bronchodilator response and airway cytology as parameters for asthma control: A randomized clinical trial Protocol ID: APITA, NCT00597064, on August 1st, 2008

Background: Clinical control is hard to define in asthma and there is little experimental data on the optimal timing, sequence and magnitude of treatment. Aim: measuring the effects of short course of oral corticoid in airway inflammation and spirometry values of asymptomatic asthma patients to define control. Methods : a double blind randomized clinical trial to observe the change in spirometry, nasal and sputum cytology in patient under combination therapy, receiving either short course of oral corticoid (OC) or placebo(P). Controlled asthma was defined by ACQ<1·5. They were submitted to clinical evaluation, nasal and sputum cytology, spirometry before and after 15±5 days of randomization. Intervention efficacy was defined by improvement of 200 mL in FEV1. Results: n=70, 73% female, age 46·8±13·1, 35 received OC and 35 P. Who received OC showed significant improvement in all spirometric parameters and abolished their positive bronchodilator response related to P. The eosinophils count in the nasal and induced sputum also reduced in OC arm. The logistic regression model identify for each one year increasing in age there was a 6% decrease in odds of intervention efficacy, associated to 19 times increase in odds related the usage of oral corticoid (related to placebo), and for each increase of 1% in bronchodilator response was associated with 9% increase in odds of efficacy (p= 0·02). Conclusion : The RCT allowed define uncontrolled asthma at baseline and the degree of bronchodilator response, younger age and usage of OC were significant predictors for functional improvement at the end of the trial. Partially funded by FAPESP.