title: Evaluation of von Willebrand factor in COPD patients.
abstract: OBJECTIVE
  To compare the absolute serum von Willebrand factor (vWF) levels and relative serum vWF activity in patients with clinically stable COPD, smokers without airway obstruction, and healthy never-smokers.
  
  
  METHODS
  The study included 57 subjects, in three groups: COPD (n = 36); smoker (n = 12); and control (n = 9). During the selection phase, all participants underwent chest X-rays, spirometry, and blood testing. Absolute serum vWF levels and relative serum vWF activity were obtained by turbidimetry and ELISA, respectively. The modified Medical Research Council scale (cut-off score = 2) was used in order to classify COPD patients as symptomatic or mildly symptomatic/asymptomatic.
  
  
  RESULTS
  Absolute vWF levels were significantly lower in the control group than in the smoker and COPD groups: 989 ± 436 pg/mL vs. 2,220 ± 746 pg/mL (p < 0.001) and 1,865 ± 592 pg/mL (p < 0.01). Relative serum vWF activity was significantly higher in the COPD group than in the smoker group (136.7 ± 46.0% vs. 92.8 ± 34.0%; p < 0.05), as well as being significantly higher in the symptomatic COPD subgroup than in the mildly symptomatic/asymptomatic COPD subgroup (154 ± 48% vs. 119 ± 8%; p < 0.05). In all three groups, there was a negative correlation between FEV1 (% of predicted) and relative serum vWF activity (r2 = -0.13; p = 0.009).
  
  
  CONCLUSIONS
  Our results suggest that increases in vWF levels and activity contribute to the persistence of systemic inflammation, as well as increasing cardiovascular risk, in COPD patients.
authors.affiliation: Rio de Janeiro State University, Rio de Janeiro, Brazil.
authors.forename: Thiago Prudente
authors.initials: TP
authors.lastname: Bártholo
authors.affiliation: Department of Pulmonology, Rio de Janeiro State University, Rio de Janeiro, Brazil.
authors.forename: Cláudia Henrique da
authors.initials: CH
authors.lastname: Costa
authors.affiliation: Department of Pulmonology, Rio de Janeiro State University, Rio de Janeiro, Brazil.
authors.forename: Rogério
authors.initials: R
authors.lastname: Rufino
mesh_terms: D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood* / Q000209:etiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000150:complications; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000097:blood; D013147:Spirometry; D014841:von Willebrand Factor / Q000032:analysis*
chemical_list: D015415:Biomarkers; D014841:von Willebrand Factor