title: Venous thromboembolism in carriers of the Factor V Leiden mutation and in patients without known thrombophilic risk factor; prediction of recurrence and APC-PCI complex concentration and/or soluble thrombomodulin antigen and activity.
abstract: BACKGROUND
  The complex between activated protein C (APC) and the protein C inhibitor (PCI) is a sensitive indicator of the degree of activation of blood coagulation and higher concentrations have been measured in carriers of the FV Leiden mutation who were in the recovery phase after treatment for venous thromboembolism (VTE).
  
  
  OBJECTIVE
  The main purpose of this study was to correlate the APC-PCI complex concentration to thrombomodulin activity and antigen concentration in the same group of patients. We also add a prospective clinical follow-up of the VTE recurrence after 1 year to investigate if the markers can predict the risk for a new VTE.
  
  
  METHODS
  Blood samples were collected from 50 patients with the FV Leiden mutation and 132 without any known risk factor for thrombophilia after finished treatment.
  
  
  RESULTS
  The APC-PCI complex, s-TM activity and the quotient (s-TM activity)/(s-TM antigen) were higher in VTE patients with FV Leiden. In total, there were 19 VTE recurrences (10%) after 1 year. The OR for recurrence was 1.9 (95% CI 0.68-5.0) in all VTE patients with elevated APC-PCI complex (above 75th percentile) and 3.6 (95% CI 1.1-12) in VTE patients without any known risk factor for thrombophilia and with elevated s-TM activity.
  
  
  CONCLUSIONS
  The APC-PCI complex concentration, s-TM activity and the quotient (s-TM activity)/(s-TM antigen) were higher in VTE patients with FV Leiden. The s-TM activity showed higher OR for recurrence of VTE in patients without known thrombophilic risk factor. Both methods could be sensitive markers of increased risk for venous thrombosis.
authors.affiliation: Department of Clinical Chemistry, Lund University, Malmö University Hospital, SE-205 02 Malmö, Sweden. karin.strandberg@med.lu.se
authors.forename: Karin
authors.initials: K
authors.lastname: Strandberg
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Svensson
authors.forename: Ann-Kristin
authors.initials: AK
authors.lastname: Ohlin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005165:Factor V / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011486:Protein C / Q000032:analysis*; D018046:Protein C Inhibitor / Q000097:blood*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D018180:Thrombomodulin / Q000097:blood*; D054556:Venous Thromboembolism / Q000097:blood* / Q000235:genetics
chemical_list: D015415:Biomarkers; D011486:Protein C; D018046:Protein C Inhibitor; D018180:Thrombomodulin; C095381:factor V Leiden; D005165:Factor V