University of Wisconsin Severe Asthma Research Program III

1. Physician diagnosis of asthma 2. Age 6 years and older 3. Evidence of historical reversibility, including either: 1\. FEV1 bronchodilator reversibility ≥ 12%, or 2\. Airway hyperresponsiveness reflected by a methacholine PC20 ≤16 mg/mL.

1. No primary medical caregiver, 2. Pregnancy (if undergoing methacholine challenge or bronchoscopy), 3. Current smoking 4. Smoking history \> 10 pack years if ≥ 30 years of age or smoking history \> 5 pack years if \< 30 years of age (Note: If a subject has a smoking history, no smoking within the past year) 5. Other chronic pulmonary disorders associated with asthma-like symptoms,including (but not limited to) cystic fibrosis, chronic obstructive pulmonary disease, chronic bronchitis, vocal cord dysfunction that is the sole cause of asthma symptoms, severe scoliosis or chest wall deformities that affect lung function, or congenital disorders of the lungs or airways, 6. History of premature birth before 35 weeks gestation, 7. Evidence that the participant or family may be unreliable or poorly adherent to their asthma treatment or study procedures, 8. Planning to relocate from the clinical center area before study completion, or 9. Any other criteria that place the subject at unnecessary risk according to the judgment of the Principal Investigator and/or attending physician(s) of record.