Bronchial thermoplasty and optical coherence tomography in severe asthma: Using light and heat to target airway remodeling

This thesis consists of two parts. In the first part, we investigated bronchial thermoplasty (BT) treatment in severe asthma patients. We showed in the multicenter international, randomized controlled TASMA trial that airway smooth muscle mass decreases with more than 50% after BT treatment. Asthma control and asthma quality of life improved in approximately 60% of the included patients (n=40). Patient characteristics associated with response were explored: higher baseline blood eosinophils and total IgE were associated with response after BT. The amount of airway smooth muscle mass at baseline and the decrease in airway smooth muscle mass after BT were not associated with clinical response. This data adds important information to further improve our understanding of BT treatment and might help with selecting the optimal patient candidate for this treatment. The second part of this thesis investigates the use of optical coherence tomography (OCT) in the airways. OCT is a novel imaging technique that uses near-infrared light to generate high resolution cross sectional images. We were able to show that OCT can identify and quantify airway wall layers and we linked the intensity of OCT images to extracellular matrix components in the airway wall. Finally, we showed that OCT is a safe technique to use in severe asthma patients and that OCT can be used to evaluate direct BT induced effects in the airway wall.