The investigators' research shows that a large subgroup of asthma patients have mucus plugs, and quantification of these plugs using a bronchopulmonary segment-based scoring system reveals a strong negative correlation between the CT (Computed Tomography) mucus plug score and FEV1 (Forced Expiratory Volume at 1 second). The FOCUS study is a single-center study that has the overarching goal to explore the biology of airway mucus plugs in asthma.~Through the FOCUS study, the investigators will initially explore the safety and tolerability of bronchoscopic removal of airway mucus plugs in patients with asthma and mucus plugs. They will then evaluate potential improvements in lung function outcomes in a dose-dependent manner (i.e., by removing mucus plugs from one lung vs both lungs). A secondary objective of the FOCUS study is to perform detailed cellular and molecular analyses of mucus and epithelial cells from airways impacted with mucus. With these biospecimens, the investigators intend to extend their preliminary findings that mucus plugged airways are characterized by intense type 2 inflammation, determine the mechanisms of epithelial and immune cell reprogramming, as well as how cellular reprogramming affects the promotion and persistence of type 2 airway inflammation.
This is a single-center study that will evaluate the safety and tolerability of removal of mucus plugs by bronchoscopy in patients with asthma. This protocol will also plan for the analysis of the features of the mucus plugs removed.