title: Protein Z in ischaemic stroke.
abstract: Many risk factors associated with ischaemic stroke are known, including high levels of fibrinogen or factor VII. Protein Z is a vitamin K-dependent coagulation factor, which was found to promote the assembly of thrombin with phospholipid vesicles that might promote coagulation. Indeed, a low protein Z level may be associated with a varying bleeding tendency. Therefore, we hypothesized that high protein Z levels could induce a hypercoagulable state and performed a case-control study to investigate a potential association between high protein Z plasma levels and ischaemic stroke. We measured protein Z in plasma samples from 157 patients with stroke of unknown aetiology and 192 control subjects. All patients had survived an ischaemic stroke or transient ischaemic attack (TIA) for at least 2 months. We found an increased relative risk of ischaemic stroke with increasing protein Z levels, with an odds ratio of 4.3 [95% confidence interval (CI): 1.7--11] for protein Z plasma levels > or = 160%. Excluding patients with a history of venous thromboembolism from the analysis, the same result was obtained (odds ratio 4.2; 95% CI: 1.6--11.2). Using a logistic regression model, this association also remained significant (P = 0.04) after adjustment for established risk factors. Our data indicated that a high plasma level of protein Z is an independent risk factor for ischaemic stroke.
authors.affiliation: Central Haematology Laboratory, Inselspital, University of Bern, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Kobelt
authors.forename: F D
authors.initials: FD
authors.lastname: Biasiutti
authors.forename: H P
authors.initials: HP
authors.lastname: Mattle
authors.forename: B
authors.initials: B
authors.lastname: Lämmle
authors.forename: W A
authors.initials: WA
authors.lastname: Wuillemin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001798:Blood Proteins / Q000032:analysis*; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012306:Risk; D020521:Stroke / Q000097:blood*
chemical_list: D001798:Blood Proteins; C026080:plasma protein Z