Efficacy Analysis Of Clarithromycin In The Treatment Of Non-eosinophilic Refractory Asthma

Objectives:To determine the efficacy of clarithromycin in patients with refractory asthma and specifically in a subgroup of patients with noneosinophilic asthma.Methods:Subjects with refractory asthma (n=45) were randomized to receive clarithromycin (500mg twice daily) or placebo for8weeks.Measurements and Main Results:The primary outcome for this study was sputum IL-8concentration. Other inflammatory outcomes assessed included sputum neutrophil numbers and concentrations of neutrophil elastase and matrix metalloproteinase (MMP)-9. Clinical outcomes were also assessed, including lung function, asthma control, quality of life, and symptoms. Clarithromycin therapy significantly reduced airway concentrations of IL-8and neutrophil numbers and improved quality-of-life scores compared with placebo. Reductions in neutrophil elastase and MMP-9concentrations were also observed. These reductions in inflammation were most marked in those with refractory noneosinophilic asthma.Conclusions:Clarithromycin therapy can modulate IL-8levels and neutrophil accumulation and activation in the airways of patients with refractory asthma. Macrolide therapy may be an important additional therapy that could be used to reduce noneosinophilic airway inflammation, particularly neutrophilic inflammation, in asthma.