title: Low level of factor V is associated with development of deep-vein thrombosis in Japanese patients.
abstract: BACKGROUND
  Factor V, having two functions (procoagulant and anticoagulant), is a key factor in blood coagulation, and low plasma levels of factor V may be a risk factor for thrombosis.
  
  
  OBJECTIVE
  The levels of plasma factor V antigen (FV:Ag), and the phospholipid binding capability of Factor V (FV:PL-bound) were evaluated in patients with deep-vein thrombosis (DVT).
  
  
  METHODS
  Levels of FV:Ag, and FV:PL-bound were expressed as a percentage of the normal level found in pooled plasma from control subjects. One hundred and twenty-three Japanese patients with deep-vein thrombosis (DVT) were included, with 100 age and sex-matched healthy control subjects.
  
  
  RESULTS
  The FV:Ag, and FV:PL-bound values were significantly lower in DVT patients than in healthy subjects (p<0.05 and p<0.005, respectively). Among the 123 patients, 30 for FV:Ag (24.4%), and 32 for FV:PL (26%) had less than the arbitrary cutoff point (set at the 5th percentile of the value for FV:Ag and FV:PL-bound from healthy subjects), and the odds ratios (ORs) were 6.1 (95% confidence interval [CI], 2.3-16.5) and 6.7 (95%CI, 2.5-17.9), respectively. When patients with a deficiency of natural anticoagulants (antithrombin, protein C, and protein S) were excluded from the analysis, the ORs increased for all patients (6.6 for FV:Ag (95%CI, 2.4-18.3) and 7.4 for FV:PL-bound (95%CI, 2.7-20.3). Moreover, twenty-one (17%) of the 123 DVT patients, and 1 (1%) of 100 control subjects had values below the cutoff points for both FV:Ag and FV:PL-bound, and the OR was 21.6 (95%CI, 2.85-163.1).
  
  
  CONCLUSIONS
  These results suggest that low levels of factor V are associated with development of DVT, and may be a predictor for DVT.
authors.affiliation: Laboratory for Clinical Investigation, Osaka University Hospital, Japan. esuehisa@hp-lab.med.osaka-u.ac.jp
authors.forename: Etsuji
authors.initials: E
authors.lastname: Suehisa
authors.forename: Tomio
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Toku
authors.forename: Yoh
authors.initials: Y
authors.lastname: Hidaka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000235:genetics*; D001681:Biological Assay; D001777:Blood Coagulation; D001789:Blood Group Antigens / Q000097:blood*; D016022:Case-Control Studies; D005165:Factor V / Q000032:analysis* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010743:Phospholipids / Q000378:metabolism; D012307:Risk Factors; D020246:Venous Thrombosis / Q000097:blood*
chemical_list: D001789:Blood Group Antigens; D010743:Phospholipids; D005165:Factor V