Detection of Airway Remodeling in Asthma Using Bronchoscopic Optical Coherence Tomography

BACKGROUND: Airway remodeling is an asthma disease hallmark that relates to asthma severity and progression.We investigated airway wall remodeling using bronchoscopic optical coherence tomography (OCT) to assess airway wall composition reflecting its extracellular matrix components and high-resolution CT (HRCT) imaging to assess airway wall thickness (AWT).RESEARCH QUESTION: Can OCT and HRCT imaging be used to detect differences in airway remodeling among healthy control participants, patients with mild to moderate asthma, and patients with severe asthma, and how does remodeling correlate with clinical disease severity and other parameters?STUDY DESIGN AND METHODS: The study population included 16 healthy control participants, 15 patients with mild to moderate asthma, and 18 patients with severe asthma.All participants were characterized extensively clinically, and both OCT and HRCT imaging were performed.RESULTS: OCT imaging high-intensity scattering area was increased in patients with severe asthma in medium airways compared with patients with mild to moderate asthma and healthy control participants.HRCT imaging-derived AWT was significantly higher in patients with asthma when compared with that of healthy control participants, but did not differentiate between levels of asthma severity.Overall in patients with asthma, a higher HRCT imaging AWT and OCT imaging high-intensity scattering area were associated with poor asthma control.Additionally, a thicker airway wall was associated with more severe airflow obstruction and higher blood eosinophil and neutrophil counts, whereas a larger high-intensity scattering area was associated with a lower number of blood eosinophils.INTERPRETATION: OCT and HRCT imaging provide different and additional information on airway wall remodeling in asthma.Bronchoscopic OCT imaging high-intensity area increases with asthma severity and correlates with poor asthma control, which emphasizes the potential of OCT imaging for assessing disease severity and therapeutic responses in patients with asthma.