Effects of Bronchial Thermoplasty on Airway Smooth Muscle and Collagen Deposition in Asthma

Rationale: The aim of bronchial thermoplastyis to improve asthma symptoms by reducing central airway smoothmuscle mass. Up to now, the reduction of smoothmuscle mass has been documented for only 1 group of 10 patients who had 15% or more of their pretreatment total bronchial biopsy area occupied by smoothmuscle.Objectives: To evaluate the effects of bronchial thermoplastyon airway smoothmuscle mass and airway collagen deposition in adult patients with asthma, regardless of pretreatment smoothmuscle area.Methods: Seventeen patients with asthma underwent bronchial thermoplastyover the course of three visits. At Visit 1, bronchial biopsies were taken from the lower lobe that was not treated during this session. At Visit 2 (3–14 wk after the first visit), all 17 patients underwent biopsy of the lower lobe treated during the first procedure. At Visit 3 (7–22 wk after the first visit), nine patients agreed to undergo biopsy of the same lower lobe. Histological and immunohistochemical analyses were perfo...