Background/Aims
Dornase alpha, a recombinant human deoxyribonuclease I, can potentiate alteplase-mediated clot lysis via breakdown of neutrophil extracellular traps. We aimed to determine if dornase potentiates clot lysis in combination with tenecteplase (TNK) using endovascularly retrieved clots, and to determine how clot components interact with lytic agents in the presence of dornase.
Methods
We modified tenecteplase with a histidine tag at its C-terminal (TNK-His) to allow visualisation of TNK-His complex formation. Retrieved clots (n=10) were suspended in buffer and incubated with 15nM TNK-His alone or combination with either 10U/ml or 100U/ml of dornase. Clot weight was measured over 90-minutes. Clot lysate supernatants were then assessed for fibrinolytic activity by fibrin zymography and western blotted to detect TNK-His complex formation, changes in plasminogen, antiplasmin and fibrinogen-degradation-products (FDPs).
Results
Addition of TNK-His to retrieved clots resulted in reduction to 64.0±28.8% (mean ± std dev) of the initial clot weight after 90-minutes. This was further reduced by 24.4% to 39.6±20.0% in the presence of 100U/ml of dornase (p<0.01 compared to TNK-His alone). Addition of 10U/ml of dornase reduced clot weight to 49.2±20.2% but this was not statistically significant compared to TNK-His alone. Western blotting revealed presence of TNK-His complexes, increase in FDPs and consumption of plasminogen and antiplasmin in the presence of dornase.
Conclusion
This study demonstrates that 100U/ml dornase potentiates TNK-His mediated clot lysis but may be less effective at lower doses. TNK complex formation and increased consumption of fibrinolytic components occurs following lysis in combination with dornase compared to TNK alone.