A simple screening assay for certain fibrinolysis parameters (FIPA)

Hemostasis, the system of generation and degradation of thrombi, consists o f coagulation and fibrinolysis. Whereas global assays to study coagulation have existed for many years, there has been no simple, rapid, and economic routine test for the plasmatic fibrinolysis parameters plasminogen activato r inhibitor-1, alpha 2-antiplasmin, plasminogen, and aprotinin. Here a fast functional global assay for these plasmatic fibrinolytic parameters is pre sented. However, the present assay is not sensitive to physiological concen trations of prourokinase or tissue-type plasminogen activator. The followin g assay conditions have been found to be optimal: 50 mu L of citrated plasm a is incubated will 50 mu L of 10 IU urinary-type plasminogen activator (ur okinase)/mL, 1.1 mmol/L tranexamic acid, 1% polygelin, 0.1% Triton X-100, p hosphate-buffered saline, pH 7.4, for 20 min at 37 degrees C (plasmin gener ation phase). Then 50 mu L of 3 mmol/L HD-NVa-CHA-Lys-pNA, 1.05 mol/L KCl i s added, and Delta A (405 nm)/10 min (37 degrees C) is determined, by using a microtiterplate reader (plasmin detection phase). The results are calibr ated against pooled normal plasma (100% plasmatic fibrinolytic parameters a ctivity). The intra- and interassay coefficients of variation have been fou nd to be less than 5%. The detection limit (sensitivity) of the functional fibrinolysis assay is 5% of the normal plasmatic fibrinolysis parameters ac tivity. The normal plasmatic fibrinolysis parameters activity is 100%, sigm a = 25%. The plasmatic fibrinolysis parameters activity correlates negative ly (r = -0.684) with the plasminogen activator inhibitor-1 activity of pati ent samples. The plasmatic fibrinolysis parameters assay is a simple, rapid , and economic functional test for several clinical relevant fibrinolysis p arameters. (C) 2000 Elsevier Science Ltd. All rights reserved.