title: Active tissue factor and activated factor XI in patients with acute ischemic cerebrovascular events.
abstract: BACKGROUND
  Elevated factor (F)XI and tissue factor (TF) have been reported to occur in patients with acute ischemic stroke (AIS). We sought to investigate whether circulating activated FXI (FXIa) and TF on admission can predict clinical outcomes in patients with acute cerebrovascular events.
  
  
  METHODS
  In the observational study, we evaluated 205 consecutive patients aged 70 years or less within the first 72 h of acute event, including 140 with AIS and 65 with transient ischemic attack (TIA). Plasma TF and FXIa activity were determined on admission in clotting assays by measuring the response to inhibitory monoclonal antibodies.
  
  
  RESULTS
  Active TF and FXIa activity were detected in 58 (28·9%) and 132 (64·4%) patients on admission, respectively. Active TF was detected in 45 of the 136 AIS patients with available TF levels (33·1%) and 13 of the 65 patients with acute TIA (20%; 0·05). Corresponding values for FXIa were 99 of the 140 (70·7%) and 33 of the 65 (50·8%; P= 0·006), respectively. Patients with detectable TF were more frequently women and hypertensive, while subjects with detectable FXIa had more often diabetes and higher levels of fibrinogen, C-reactive protein and interleukin-6 (all P < 0·05). Patients with detectable FXIa but not TF had higher National Institutes of Health Stroke Scale score, higher modified Rankin scale score and lower Barthel Index at discharge (all P < 0·05).
  
  
  CONCLUSIONS
  Circulating active TF and FXIa occur frequently in acute cerebrovascular ischemic events. Active FXIa in plasma might be useful as a novel risk marker of worse functional outcomes in patients with acute cerebrovascular events.
authors.affiliation: Institute of Cardiology, Jagiellonian University Medical College, Krakow, Poland. mmundas@cyf-kr.edu.pl
authors.forename: Anetta
authors.initials: A
authors.lastname: Undas
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Slowik
authors.forename: Matthew
authors.initials: M
authors.lastname: Gissel
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Mann
authors.forename: Saulius
authors.initials: S
authors.lastname: Butenas
mesh_terms: D000368:Aged; D001777:Blood Coagulation / Q000502:physiology; D001780:Blood Coagulation Tests; D015945:Factor XIa / Q000378:metabolism*; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012720:Severity of Illness Index; D013925:Thromboplastin / Q000378:metabolism*; D013997:Time Factors
chemical_list: D013925:Thromboplastin; D015945:Factor XIa