title: Elevated circulating PAI-1 levels are related to lung function decline, systemic inflammation, and small airway obstruction in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Plasminogen activator inhibitor-1 (PAI-1) and soluble urokinase-type plasminogen activator receptor (suPAR) participate in inflammation and tissue remolding in various diseases, but their roles in chronic obstructive pulmonary disease (COPD) are not yet clear. This study aimed to investigate if PAI-1 and suPAR were involved in systemic inflammation and small airway obstruction (SAO) in COPD.
  
  
  METHODS
  Demographic and clinical characteristics, spirometry examination, and blood samples were obtained from 84 COPD patients and 51 healthy volunteers. Serum concentrations of PAI-1, suPAR, tissue inhibitor of metalloproteinase-1 (TIMP-1), Matrix metalloproteinase-9 (MMP-9), and C-reactive protein (CRP) were detected with Magnetic Luminex Screening Assay. Differences between groups were statistically analyzed using one-way analysis of variance or chi-square test. Pearson's partial correlation test (adjusted for age, sex, body mass index, cigarette status, and passive smoke exposure) and multivariable linear analysis were used to explore the relationships between circulating PAI-1 and indicators of COPD.
  
  
  RESULTS
  First, we found that serum PAI-1 levels but not suPAR levels were significantly increased in COPD patients compared with healthy volunteers (125.56±51.74 ng/mL versus 102.98±36.62 ng/mL,P=0.007). Then, the correlation analysis showed that circulating PAI-1 was inversely correlated with pulmonary function parameters including the ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC), FEV1/Pre (justifiedr=-0.308,P<0.001; justifiedr=-0.295,P=0.001, respectively) and SAO indicators such as FEV3/FVC, MMEF25-75/Pre (justifiedr=-0.289,P=0.001; justifiedr=-0.273,P=0.002, respectively), but positively related to the inflammatory marker CRP (justifiedr=0.351,P<0.001), the small airway remolding biomarker TIMP-1, and MMP-9 (justifiedr=0.498,P<0.001; justifiedr=0.267,P=0.002, respectively). Besides, multivariable linear analysis showed that FEV1/FVC, CRP, and TIMP-1 were independent parameters associated with PAI-1.
  
  
  CONCLUSIONS
  Our findings first illustrate that elevated serum PAI-1 levels are related to the lung function decline, systemic inflammation, and SAO in COPD, suggesting that PAI-1 may play critical roles in the pathogenesis of COPD.
authors.affiliation: Department of Respiratory and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China; Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Respiratory and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China; Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Yang
authors.affiliation: Department of Respiratory and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China; Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Diandian
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Respiratory and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China; Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Yanqiu
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Respiratory and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China; Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Xue
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Respiratory and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China; Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Caishuang
authors.initials: C
authors.lastname: Pang
authors.affiliation: Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Junlong
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Binwu
authors.initials: B
authors.lastname: Ying
authors.affiliation: Department of Respiratory and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China; Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Respiratory and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China; Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital of Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Wen
mesh_terms: D000368:Aged; D000402:Airway Obstruction / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D016014:Linear Models; D008168:Lung / Q000503:physiopathology*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood; D008875:Middle Aged; D015999:Multivariate Analysis; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D055293:Receptors, Urokinase Plasminogen Activator / Q000097:blood; D013147:Spirometry; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000097:blood; D015854:Up-Regulation; D014797:Vital Capacity
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; C524898:PLAUR protein, human; D017395:Plasminogen Activator Inhibitor 1; D055293:Receptors, Urokinase Plasminogen Activator; C051321:SERPINE1 protein, human; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D002097:C-Reactive Protein; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9
keywords: chronic obstructive pulmonary disease (COPD); plasminogen activator inhibitor-1 (PAI-1); small airway obstruction (SAO); systemic inflammation