title: Impact of factor VIII and von Willebrand factor plasma levels on cerebral venous and sinus thrombosis: are they independent risk factors?
abstract: BACKGROUND
  The aim of this study was to assess the plasma levels of factor VIII (FVIII), von Willebrand factor (vWF) and their association in patients with cerebral venous sinus thrombosis (CVST).
  
  
  METHODS
  We prospectively included 25 CVST patients admitted to the university hospital and 53 voluntary subjects as a control group. FVIII and vWF were measured after 6 months when anticoagulant therapy was stopped.
  
  
  RESULTS
  The mean FVIII and vWF levels were significantly higher in the CVST group compared to the control group (126.21 ± 54.69 vs. 91.9 ± 48.8 IU/dl; p = 0. 012; 157.05 ± 107.74 vs. 94 ± 84%; p = 0.01, respectively). Using analyses calculating the 95th percentile cut-off values, we found high levels of FVIII in patients compared to controls (29.2 vs. 5%; p = 0.01) and the odds ratio with 95% confidence interval (CI) was 7.82 (1.46, 41.6). After adjustment for vWF levels, sex and age, the risk remained significantly increased and the odds ratio with 95% CI was 10.5 (1.1, 101.4) (p = 0.041).
  
  
  CONCLUSIONS
  FVIII is one of the most prevalent risk factors of CVST and may be associated with an approximately tenfold increased risk for developing CVST. This effect is independent of vWF levels; however, vWF is not an independent risk factor of CVST.
authors.affiliation: Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: T
authors.initials: T
authors.lastname: Shahsavarzadeh
authors.forename: S H
authors.initials: SH
authors.lastname: Javanmard
authors.forename: M
authors.initials: M
authors.lastname: Saadatnia
mesh_terms: D000293:Adolescent; D000328:Adult; D016001:Confidence Intervals; D005169:Factor VIII / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D012851:Sinus Thrombosis, Intracranial / Q000097:blood*; D055815:Young Adult; D014841:von Willebrand Factor / Q000276:immunology* / Q000378:metabolism
chemical_list: C029417:Von Willebrand antigen; D014841:von Willebrand Factor; D005169:Factor VIII