[Parameters related to fibrinolysis and their meanings].

To accurately assess fibrinolytic activity in plasma, many different assay methods are employed. We divided these to three categories by their capabilities. The method to assay plasminogen activation potential is the first, which is essentially determined by the balance between tissue plasminogen activator (tPA) and plasminogen activator inhibitor type 1(PA-1), and could be evaluated by plasma levels of these molecules as well as euglobulin clot lysis time (ECLT). The method to assay plasmin-dependent fibrin degradation potential is the second, which is mainly influenced by thrombin activatable fibrinolysis inhibitor (TAFI) and alpha2-antiplasmin, and could be evaluated by plasma levels of these modifiers as well as tPA supplemented plasma clot lysis time. The method to estimate ongoing status of fibrinolytic reaction in-vivo is the last, which could be evaluated by plasma levels of FDP including D-dimer and alpha2-antiplasmin-plasmin complex. Employing the methods in the first two categories, we may estimate the risk for thrombosis. Employing the methods in the last two categories, we may estimate the effectiveness as well as the bleeding risk of thrombolytic therapy. These assay methods are described together with underlying molecular mechanisms at each step of fibrinolytic system.