Inclusion Criteria:  Age 18-60 Confirmed diagnosis of asthma by CTS criteria No contraindication to bronchoscopy No treatment with azithromycin No oral corticosteroid in the 4 weeks prior No participation in another drug study in the 4 weeks prior On stable doses of asthma inhaled therapies for 12 weeks prior to bronchoscopy FEV1 >80%  Exclusion Criteria:  Current smokers (within past year) Subjects with ≥10 pack-year lifetime smoking history History of asthma exacerbation (requiring oral prednisone) in the 4 weeks prior to study entry