Abstract: The invention is based upon the discovery that PAI-1 activity of a sample can be measured with sensitivity and correlation to in vivo activity without the use of standard curves. The assay determines the PAI-1 activity of a sample upon utilizing the second order rate equation for the reaction of PAI-1 and t-PA, as measured by their activities, in that sample.

Abstract: This invention provides an improved method for enhancing the activity of thrombolytic agents, including t-PA, scu-PA, tcu-PA, streptokinase, acylated plasminogen-streptokinase activator complex (APSAC), mixtures of these, and other activators of plasminogen. The enhancement method comprises supplementation of plasma plasminogen levels with deglycosylated forms of glu- and lys-plasminogen. Deglycosylated plasminogen refers herein to glu- or lys-plasminogen 2 having a single oligosaccharide chain at Thr.sub.345, plasminogens having a single oligosaccharide chain at Asn.sub.288, and unglycosylated forms of plasminogen. The work described herein shows that a less glycosylated form of plasminogen (glu-plasminogen 2) has a higher affinity for fibrin clots than a more glycosylated plasminogen (glu-plasminogen 1).