Monitoring of Functional Plasminogen in the Blood of Patients on Fibrinolytics

Abstract

There are no reliable data on functional plasminogen in the blood of patients receiving fibrinolytic treatment. Here, artifactual in vitro changes of functional plasminogen were prevented by arginine stabilization blood samples of myocardial infarction patients: 12 received 36.4 mg reteplase in bolus, and 1 patient received 100 mg tissue plasminogen activator in continuous infusion. Arginine (1.5 M, 1.3 mL, pH 8.7) was used to stabilize 2.6 mL ethylenediaminetetraacetic acid-blood. The arginine-stabilized plasma was analyzed with a functional oxidative assay for plasminogen. Functional plasminogen decreased within 2 minutes of reteplase treatment by about 40% and by about 80% after 60 minutes. Lowest plasminogen concentrations were found in plasmas with highest plasmin activities. Chloramine oxidation of purified Glu-plasminogen increased its activation by urokinase up to 3-fold. Arginine stabilization allows reliable determinations of functional plasminogen in the blood of patients receiving fibrinolytics, enabling the rapid diagnosis of prothrombotic plasminogen consumption. The present findings support the profibrinolytic action of chloramines.