Background Bronchial Thermoplasty (BT) is an endoscopic treatment for severe asthma using radiofrequency energy to target airway remodeling including smooth muscle. The correlation of pulmonary... Show moreBackground Bronchial Thermoplasty (BT) is an endoscopic treatment for severe asthma using radiofrequency energy to target airway remodeling including smooth muscle. The correlation of pulmonary function tests and BT response are largely unknown. Forced Oscillation Technique (FOT) is an effort-independent technique to assess respiratory resistance (Rrs) by using pressure oscillations including small airways. Aim To investigate the effect of BT on pulmonary function, assessed by spirometry, bodyplethysmography and FOT and explore associations between pulmonary function parameters and BT treatment response. Methods Severe asthma patients recruited to the TASMA trial were analyzed in this observational cohort study. Spirometry, bodyplethysmography and FOT measurements were performed before and 6 months after BT. Asthma questionnaires (AQLQ/ACQ-6) were used to assess treatment response. Results Twenty-four patients were analyzed. AQLQ and ACQ improved significantly 6 months after BT (AQLQ 4.15 (+/- 0.96) to 4.90 (+/- 1.14) and ACQ 2.64 (+/- 0.60) to 2.11 (+/- 1.04), p = 0.004 and p = 0.02 respectively). Pulmonary function parameters remained stable. Improvement in FEV1 correlated with AQLQ change (r = 0.45 p = 0.03). Lower respiratory resistance (Rrs) at baseline (both 5 Hz and 19 Hz) significantly correlated to AQLQ improvement (r = - 0.52 and r = - 0.53 respectively, p = 0.01 (both)). Borderline significant correlations with ACQ improvement were found (r = 0.30 p = 0.16 for 5 Hz and r = 0.41 p = 0.05 for 19 Hz). Conclusion Pulmonary function remained stable after BT. Improvement in FEV1 correlated with asthma questionnaires improvement including AQLQ. Lower FOT-measured respiratory resistance at baseline was associated with favorable BT response, which might reflect targeting of larger airways with BT. Show less
This thesis comprises data from the GLUCOLD study (Groningen Leiden Universities and Corticosteroids in Obstructive Lung Disease), a prospective study in COPD. In chapter 2 is shown that airflow... Show moreThis thesis comprises data from the GLUCOLD study (Groningen Leiden Universities and Corticosteroids in Obstructive Lung Disease), a prospective study in COPD. In chapter 2 is shown that airflow limitation, asthma-like components, exhaled nitric oxide and sputum inflammatory cell counts offer separate and additive information about the pathophysiological condition of COPD. Chapter 3 shows that uneven distribution of ventilation and airway closure in stable COPD are associated with neutrophilic inflammation in bronchial biopsies and bronchoalveolar lavage fluid. Chapter 4 and 5 show that ex-smokers with COPD have higher bronchial CD4+ and plasma cell numbers, and less bronchial epithelial mucin stores, proliferating cells, and squamous cell metaplasia than current smokers, whereas neutrophil, macrophage, and CD8+ cell numbers are not different between both groups. Bronchial inflammation and epithelial changes are associated with duration of smoking cessation. Chapter 6 shows that long-term treatment with inhaled corticosteroids in COPD reduces bronchial T-lymphocyte and mast cell numbers, whilst increasing bronchial epithelial integrity and bronchial eosinophil numbers. This is accompanied by a reduced FEV1 decline and improved airway hyperresponsiveness, dyspnea and quality of life. Discontinuation of inhaled corticosteroids at 6 months leads to a relapse of bronchial inflammation and clinical outcome. Show less
