title: Irreversible airway obstruction assessed by high-resolution computed tomography (HRCT), exhaled nitric oxide (FENO), and biological markers in induced sputum in patients with asthma.
abstract: OBJECTIVE
  The objective of this study was to explore the significance of assessing irreversible airway obstruction (IAO) in asthma patients by high-resolution computed tomography (HRCT), biological markers in induced sputum, and exhaled nitric oxide (FENO).
  
  
  METHODS
  The study was conducted in 34 patients with IAO, 46 patients with reversible airway obstruction (RAO), 40 patients who did not have airway obstruction (NAO), and 40 healthy subjects serving as controls. These patients received a step therapy for at least 3 months based on the guidelines for the prevention and treatment of asthma. After achieving complete or partial control of asthma, HRCT, lung function, FENO, and chemokine levels in induced sputum were measured.
  
  
  RESULTS
  The airway wall area (WA; %) correlated with forced expiratory volume-1 (FEV-1(L); r = -0.67, p < 0.0001), and significant differences in bronchial wall thickening (BWT) of the LEVEL E generation airways were observed between the asthma and control groups (p < 0.01). FENO levels correlated with FEV-1 (%) in the IAO group (r = 0.49, p = 0.01). The levels of matrix metalloproteases-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in asthma patients with IAO, RAO, and NAO were significantly higher than those in the controls (p < 0.05). The level of neutrophilia in the sputum from the IAO group was higher than that from the RAO, NAO and control groups.
  
  
  CONCLUSIONS
  Asthma patients with IAO have an increased BWT. Airway measurements with HRCT scans appear to be valuable in the evaluation of airway remodeling in asthma patients with IAO.
authors.affiliation: Department of Respiration Medicine, West China Hospital, Sichuan University, 37 Guoxuexiang, 610041, Chengdu, Sichuan, China, taosen666@vip.tom.com.
authors.forename: Lanlan
authors.initials: L
authors.lastname: Zhang
authors.forename: Jin
authors.initials: J
authors.lastname: Gang
authors.forename: Cao
authors.initials: C
authors.lastname: Zhigang
authors.forename: Cui
authors.initials: C
authors.lastname: Yali
authors.forename: Shen
authors.initials: S
authors.lastname: Baozhong
authors.forename: Zhang
authors.initials: Z
authors.lastname: Fangbiao
authors.forename: Chuntao
authors.initials: C
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D001249:Asthma / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D011659:Pulmonary Gas Exchange; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013183:Sputum / Q000737:chemistry*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide