title: Risk factors related to persistent airflow obstruction in severe asthma in Chinese Han population.
abstract: OBJECTIVE
  To explore the significance of assessing persistent airway obstruction (PAO) in asthma patients by airway wall remodeling with bronchoscopy, high-resolution computed tomography (HRCT), and biological markers in the induced sputum and serum, exhaled nitric oxide (FENO), and lung function.
  
  
  METHODS
  The study was conducted in 119 patients with PAO and 125 patients with reversible airway obstruction (RAO). Endobronchial biopsy specimens were analyzed for airway smooth muscle (ASM) area, and reticular basement membrane (RBM) thickness. Airway thickness was also measured by HRCT scanning. Levels of matrix metalloproteases-9 (MMP-9), metalloproteinase 33 (ADAM33), and vascular endothelial growth factor (VEGF) were measured in the induced sputum and serum by enzyme linked immunosorbent assay.
  
  
  RESULTS
  PAO was associated with longer disease duration, absence of atopy and rhinitis, and larger ASM area (SMA%) (15.83%±2.32% [n=9] vs. 8.0%±1.68% [n=7], P=0.02), thicker RBM (16.27±2.32 μm [n=9] vs. 8.71±2.41 μm [n=7], P=0.042); No differences in any of the biomarker molecules measured in airway thickness in HRCT, sputum and blood individually between groups were found.
  
  
  CONCLUSIONS
  Severe asthma patients with longer disease duration and the absence of atopy and rhinitis are more likely to develop PAO in Chines Han population. PAO patients have increased ASM area and RBM thickness appear to be valuable in the evaluation of airway remodeling in asthma patients in Chinese Han population.
authors: Department of Respiration Medicine, West China Hospital, Sichuan University Chengdu, Sichuan, China.
authors: Lanlan
authors: L
authors: Zhang
authors: Department of Respiration Medicine, West China Hospital, Sichuan University Chengdu, Sichuan, China.
authors: Wenjuan
authors: W
authors: Yang
authors: Pathology of Respiration Medicine, West China Hospital, Sichuan University Chengdu, Sichuan, China.
authors: Qiao
authors: Q
authors: Zhou
authors: Department of Integration of Traditional Chinese and Western Medicine, West China Hospital, Sichuan University Chengdu, Sichuan, China.
authors: Gang
authors: G
authors: Wang
authors: Department of Respiration Medicine, West China Hospital, Sichuan University Chengdu, Sichuan, China.
authors: Chuntao
authors: C
authors: Liu
keywords: Bronchoscopy; high-resolution computed tomography (HRCT); persistent airway obstruction (PAO); reversible airway obstruction (RAO)