Asthmatics able to step down from inhaled corticosteroid treatment without loss of asthma control have low serum eotaxin/CCL11

Abstract

The addition of a long-acting beta2 agonist (LABA) to inhaled corticosteroid (ICS) may control asthma better than ICS alone. Eosinophil markers may predict symptom severity in asthma. The effect of combination treatment on moderate to severe asthmatics not selected to respond rapidly to steroid deprivation was compared with monotherapy. The ability of serum markers to predict symptom severity was assessed. Asthmatics treated adequately with ICS (750-1000 mcg ICS daily) were randomised to receive ICS (fluticasone propionate) + LABA (salmeterol) (500 mcg/50 mcg bd) or ICS alone (500 mcg bd). If asthma was controlled at clinic visits every 6 weeks, ICS dose was tapered until asthma exacerbated (hospitalisation, ICS above study medication, peak flow variation, decline in forced expiratory volume in 1 s and/or use of rescue medication), or placebo was maintained for 6 weeks. Efficacy of the treatments was compared. Serum cytokines and chemokines were compared among the groups reporting severe, mild or no symptoms. There was no difference between the treatment arms in the clinical analysis. Nine patients could be maintained on placebo for 6 weeks, 36 developed mild symptoms and 16 developed severe symptoms. Patients on placebo for 6 weeks had significantly lower serum eotaxin at baseline than patients with symptoms. Patients with mild symptoms had intermediate serum eotaxin concentrations. Patients with asthma controlled on ICS respond heterogeneously to ICS tapering. Serum eotaxin/CCL11 may be useful in predicting the severity of symptoms patients develop during steroid tapering and should be evaluated in guiding asthma treatment.