Effect of bronchial thermoplasty on structural changes and inflammatory mediators in the airways of subjects with severe asthma

• Published in: Respiratory medicine Vol. 150; pp. 165 - 172
• Main Authors: Ichikawa, Tomohiro, Panariti, Alice, Audusseau, Severine, Mogas, Andrea Karen, Olivenstein, Ronald, Chakir, Jamila, Laviolette, Michel, Allakhverdi, Zoulfia, Al Heialy, Saba, Martin, James G., Hamid, Qutayba
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2019; Elsevier Limited
• Subjects: Actin; Actins - metabolism; Actins - radiation effects; Adult; Airway nerves; Airway remodeling; Airway Remodeling - radiation effects; Airway smooth muscle; Antigens; Asthma; Asthma - therapy; Biopsy; Blood vessels; Bronchi - pathology; Bronchial thermoplasty; Bronchial Thermoplasty - adverse effects; Bronchial Thermoplasty - methods; Bronchoscopy; Bronchoscopy - methods; Female; Humans; Inflammation; Inflammation Mediators - metabolism; Inflammation Mediators - radiation effects; Inflammatory mediators; Innervation; Interleukin-17 - metabolism; Interleukin-17 - radiation effects; Male; Middle Aged; Proteins - metabolism; Proteins - radiation effects; Questionnaires; Radiofrequency Therapy - methods; Respiratory Function Tests - statistics & numerical data; Respiratory tract; Severe asthma; Severity of Illness Index; Smooth muscle; Transforming growth factor; Transforming Growth Factor beta1 - metabolism; Transforming Growth Factor beta1 - radiation effects; Transforming growth factor-b1; Von Willebrand factor; von Willebrand Factor - metabolism; von Willebrand Factor - radiation effects; United States > US; Bronchial thermoplasty; Airway remodeling; Severe asthma; Inflammatory mediators; Airway smooth muscle; Airway nerves
• DOI: 10.1016/j.rmed.2019.03.005
• ISSN: 0954-6111; 1532-3064

Bronchial thermoplasty (BT) is a novel technique used in the treatment of subjects with severe refractory asthma. Radiofrequency is provided to airway walls during bronchoscopy in order to reduce airway remodeling. Several clinical studies have reported an improvement in subjects’ symptoms following BT. However, how BT affects the airway architectures and inflammatory mediators in the airways has not been yet fully elucidated. Fourteen subjects with severe asthma were recruited in this study according to the criteria of ATS severe asthma definition. The study subjects undertook bronchial biopsy during the bronchoscopy procedure at baseline and 6 weeks after the initial BT treatment. The obtained samples were stained with antibodies for α-smooth muscle actin (α-SMA); protein gene product (PGP) 9.5, a specific nerve marker; von Willebrand factor (vWF), a marker for blood vessels; interleukin-17A (IL-17A) and transforming growth factor-β1 (TGF-β1). The expression of α-SMA and PGP9.5 were significantly reduced post-BT. There was no significant difference in the number of blood vessels between baseline and post-BT. In addition, BT did not affect the production of IL-17A and TGF-β1 in the airways. The changes in the expression of α-SMA and PGP9.5 had no significant correlation with the improvement of pulmonary function. and Clinical Relevance: This study suggests that BT reduces airway smooth muscle mass and the airway innervation without affecting vasculature and the production of inflammatory mediators in the airways of subjects with severe asthma. •Bronchial thermoplasty (BT) is a valuable tool for treating severe asthma.•BT reduces the airway smooth muscle mass and airway innervation.•BT has no effect on vascularity and inflammatory mediators.