title: Venous thrombosis risk associated with plasma hypofibrinolysis is explained by elevated plasma levels of TAFI and PAI-1.
abstract: Elevated plasma clot lysis time (CLT) increases risk of venous and arterial thrombosis. It is unclear which fibrinolytic factors contribute to thrombosis risk. In 743 healthy control subjects we investigated determinants of CLT. By comparison with 770 thrombosis patients, we assessed plasma levels of fibrinolytic proteins as risk factors for a first thrombosis. Plasminogen activator inhibitor-1 (PAI-1) levels were the main determinants of CLT, followed by plasminogen, thrombin-activatable fibrinolysis inhibitor (TAFI), prothrombin, and alpha2-antiplasmin. Fibrinogen, factor VII, X, and XI contributed minimally. These proteins explained 77% of variation in CLT. Levels of the fibrinolytic factors were associated with thrombosis risk (odds ratios, highest quartile vs lowest, adjusted for age, sex, and body mass index: 1.6 for plasminogen, 1.2 for alpha2-antiplasmin, 1.6 for TAFI, 1.6 for PAI-1, and 1.8 for tissue plasminogen activator [t-PA]). Adjusting for acute-phase proteins attenuated the risk associated with elevated plasminogen levels. The risk associated with increased t-PA nearly disappeared after adjusting for acute-phase proteins and endothelial activation. TAFI and PAI-1 remained associated with thrombosis after extensive adjustment. In conclusion, CLT reflects levels of all fibrinolytic factors except t-PA. Plasminogen, TAFI, PAI-1, and t-PA are associated with venous thrombosis. However, plasminogen and t-PA levels may reflect underlying risk factors.
authors.affiliation: Department of Clinical Chemistry and Hematology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Mirjam E
authors.initials: ME
authors.lastname: Meltzer
authors.forename: Ton
authors.initials: T
authors.lastname: Lisman
authors.forename: Philip G
authors.initials: PG
authors.lastname: de Groot
authors.forename: Joost C M
authors.initials: JC
authors.lastname: Meijers
authors.forename: Saskia
authors.initials: S
authors.lastname: le Cessie
authors.forename: Carine J M
authors.initials: CJ
authors.lastname: Doggen
authors.forename: Frits R
authors.initials: FR
authors.lastname: Rosendaal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001780:Blood Coagulation Tests; D025901:Carboxypeptidase B2 / Q000097:blood*; D005260:Female; D005342:Fibrinolysis; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood*; D018570:Risk Assessment; D012307:Risk Factors; D020246:Venous Thrombosis / Q000097:blood*; D055815:Young Adult
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D025901:Carboxypeptidase B2