Study of Focal Airway Disease in Asthma Using Image Guided Bronchoscopy

Group 1: Healthy Controls Inclusion Criteria: * Male or female between the ages of 18 and 70 years at Visit 1 and at least 50% whose age is \> 40 years (to ensure age balance among groups and anticipating that group 3 subjects will be older). * Written informed consent obtained from subject and ability for subject to comply with the requirements of the study. * Able to perform reproducible spirometry according to ATS criteria. Exclusion Criteria: * Upper respiratory tract infection (URI) within the previous 6 weeks. * History of lung disease. * Smoking of tobacco or other recreational inhalants in last month and/or \>10 pack-year smoking history. * Currently pregnant. * History of allergic rhinitis. * Laboratory evidence of atopy (blood eosinophils \> 0.4 cells/dL, IgE \> 165 IU/mL) * History of unstable cardiovascular disease. * BMI \> 45 * Currently taking anticoagulants. Group 2: Asthmatic Subjects without Mucus Plugs Inclusion Criteria: * Male or female between the ages of 18 and 70 years at Visit 1 and at least 50% whose age is \> 40 years (to ensure age balance among groups and anticipating that group 3 subjects will be older). * Written informed consent obtained from subject and ability for subject to comply with the requirements of the study. * Able to perform reproducible spirometry according to ATS criteria. * Physiological evidence of airflow obstruction (FEV1 bronchodilator reversibility of ≥ 12% or hyperreactivity to methacholine reflected by a methacholine PC20 ≤ 16 mg/mL). Historical methacholine data from previous studies conducted in the past 5 years at the UCSF ACRC will be allowed. * Clinical history of asthma per patient report or medical record. * Asthma requiring treatment with inhaled corticosteroids (ICS) for 3 months or greater. Exclusion Criteria: * Asthma exacerbation or URI within the previous 6 weeks. * Currently pregnant. * Smoking of tobacco or other recreational inhalants in last month and/or \>10 pack-year smoking history. * Other chronic pulmonary disorders, including cystic fibrosis and chronic obstructive pulmonary disease. * History of unstable cardiovascular disease. * BMI \> 45. * Currently taking anticoagulants. Group 3: Asthmatic Subjects with Mucus Plugs Inclusion: * Male or female between the ages of 18 and 70 years at Visit 1. * Written informed consent obtained from subject and ability for subject to comply with the requirements of the study. * Able to perform reproducible spirometry according to ATS criteria. * Physiological evidence of airflow obstruction (FEV1 bronchodilator reversibility of ≥ 12% or hyperreactivity to methacholine reflected by a methacholine PC20 ≤ 16 mg/mL). Historical methacholine data from previous studies conducted in the past 5 years at the UCSF ACRC will be allowed. * Clinical history of asthma per patient report or medical record. * Asthma requiring treatment with inhaled corticosteroids (ICS) for 3 months or greater. * A MDCT lung scan indicating a mucus plug accessible by bronchoscopy in at least one airway. Exclusion Criteria: * Asthma exacerbation or URI within the previous 6 weeks. * Currently pregnant. * Smoking of tobacco or other recreational inhalants in last month and/or \>10 pack-year smoking history. * Other chronic pulmonary disorders, including cystic fibrosis and chronic obstructive pulmonary disease. * History of unstable cardiovascular disease. * BMI \> 45. * Currently taking anticoagulants. * Mucus plugs inaccessible by bronchoscope.