IS NORMAL BRONCHIAL RESPONSIVENESS IN ASTHMATICS A RELIABLE INDEX FORWITHDRAWING INHALED CORTICOSTEROID TREATMENT

Study objective: Inhaled corticosteroid (ICS) treatment is first-line maintenance therapy in bronchial asthma. However, it is not clear whet her and when ICS treatment can be withdrawn. The aim of this open stud y was to assess whether normalization of bronchial responsiveness coul d be used as a reliable index to assess the opportunity of ICS treatme nt withdrawal. Design: Open study at two different points in time. Set ting: Outpatient pulmonary clinic. Patients: Eighteen asthmatic subjec ts. Measurements and results: ICS therapy was withdrawn in subjects tr eated with beclomethasone dipropionate, at the maintenance dose of 889 +/-246 mu g/d for >3 months. Upon recruitment, all subjects were asymp tomatic, had FEV1 >70% of predicted value, and were in treatment with beta(2)-agonists on an as-needed basis. Eight subjects (group 1) had n ormal bronchial responsiveness (methacholine provocative dose causing a 20% fall in FEV1 [PD20] >2,000 mu g) and 10 subjects (group 2) had b ronchial hyperresponsiveness (BHR) (PD(20)less than or equal to 2,000 mu g) After withdrawal of ICS treatment, subjects were followed up for 3 weeks and were asked to record their asthma symptoms (cough, dyspne a, and wheezing) and their beta(2)-agonist use. At recruitment and at the end of follow-up, subjects underwent spirometry and a methacholine challenge test. Frequency of asthma exacerbation was similar in subje cts with normal bronchial responsiveness (NBR) and in subjects with BH R (50% vs 60%), but subjects with NBR tended to remain asymptomatic fo r longer than those with BHR (mean+/-SD, 10.7+/-4.4 days vs 5.5+/-3.8 days) (p=0.08). None of the subjects reported any condition that could have triggered exacerbation. Asthma exacerbation was associated with a significant decrease in FEV1 (-105+/-107 mt; p<0.05) and in PD20 (-1 ,332+/-1,020 mu g; p<0.001). Conclusions: Our study shows that the Lik elihood of asthma exacerbation is not reduced if ICS treatment is with drawn when the subjects have NBR, but the exacerbation could be delaye d. Further studies in larger populations of asthmatics are needed to c onfirm these findings.