In vitro investigation of streptokinase activity using Sonoclot coagulation analysis

Streptokinase (SK) therapy has become a common clinical intervention in the treatment of acute coronary syndromes. Recent clinical trials indicate that adjuvant treatment with low molecular weight heparin (LMWH) or bivalirudin (BV) may attenuate fibrinolytic-induced procoagulant activity. We investigated the effects of SK with LMWH and BV on the clotting of whole blood using a Sonoclot^® Coagulation Analyzer. Human citrated whole blood was spiked with SK and LMWH at final concentrations of control, 5 U/mL SK, 0.2 U/mL LMWH, and 5 U/mL SK:0.2 U/mL LMWH. The samples (n=10) were incubated at 37°C for 10 minutes and recalcified with CaCl₂ to initiate clotting. Tracings were obtained using the Sonoclot Signature Viewer™ software, and the clotting time (CT) and clot viscosity were noted. The experiment was repeated (n=8) using 5 μg/mL BV in place of LMWH. The Sonoclot tracings provide a whole-picture analysis of the effects of SK and adjuvant anticoagulants on haemostatic and fibrinolytic mechanisms. Implementation of coagulation monitoring protocols for SK therapy may aid in clinical diagnosis.