PREDICTIVE VALUE FOR THROMBOTIC DISEASE OF PLASMINOGEN-ACTIVATOR INHIBITOR-1 PLASMA-LEVELS

Plasminogen activator inhibitor-I plays a major role in the fibrinolyt ic system as the main physiological inhibitor of both tissue-type and urinary-type plasminogen activators. The inhibitor is present in plasm a in small amounts and derives mainly from endothelial cells. Positive correlations have been reported between plasma levels and different p arameters, such as serum triglycerides, insulin plasma levels and body mass index. Moreover, high plasma inhibitor concentrations have been observed in different disease states, but it must be stressed that pla sminogen activator inhibitor-1 behaves as an acute-phase reactant and measurement of plasma levels is not significant in the acute phase of the disease. A possible predictive value of inhibitor levels for throm botic events such as deep vein thrombosis and ischemic heart disease h as been studied. On the basis of available studies, the predictive val ue is not clear for venous thrombosis, whereas plasminogen activator i nhibitor-1 levels can predict some coronary events, at least in subgro ups of young patients with a first myocardial infarction. It remains t o be established if treatments able to reduce plasma inhibitor levels lead to a decrease in the risk of thromboembolic events.