Abstract

INTRODUCTION

Bronchial thermoplasty (BT) is a non pharmacological intervention for severe asthma.

AIM

To analyze the result of BT  on clinical parameters a year after the procedure, comparing with the previous period,  and its effect on nerve fibers.

METHODS

We collected bronchial biopsies from 12 patients who underwent BT. Biopsies were performed at baseline (T0), and after 1 (T1), 2 (T2) and 12 (T12) months post-BT and studied with immunocytochemistry and microscopy methods. Clinical data including Asthma Quality of Life (AQLQ) and Asthma Control Questionnaire (ACQ) scores, exacerbations , hospitalizations, oral steroids (OCS) use, lost work days.

RESULTS

Significant reduction of nerve fibers at T1, T2 and T12 was observed in the submucosa and in airway smooth muscle (AMS) compared to T0 A significant improvement in AQLQ and ACQ was found from T0 to T3 and T12, at T3 and T12 exacerbation was significantly reduced (Fig. 1). OCS use decreased from 21.2±13.8 mg/day to 6.6±8.6 mg/day (p=0.026); 6 patients stopped it. The number of lost work days decreased sharply form 27.2±21.3 in the year pre-BT to 0.3±0.8 (p=0.024) in the year post-BT.

CONCLUSIONS      

A significant improvement of clinical parameters were observed in the year after BT. A reduction of nerve fibers in epithelium and in ASM occurs earlier and persists at one year after BT. We propose that nerve ablation may contribute to mediate the beneficial effects of BT in severe asthma.