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Fibrinolysis and COVID-19: A plasmin paradox
Robert L Medcalf1, Charithani B Keragala1, Paul S Myles2,3
1Australian Centre for Blood Diseases, Monash University, Melbourne, Victoria, Australia.
Insights
COVID-19 causes unique coagulopathy with high D-dimer. This may signal a failing fibrinolytic system, but timing is crucial for treatment effectiveness.
Area of Science:
- Thrombosis and Hemostasis
- COVID-19 Pathophysiology
- Fibrinolysis
Background:
- The COVID-19 pandemic presents challenges in thrombosis and hemostasis, including novel coagulopathies.
- Exceptionally high D-dimer levels are observed, prompting investigation into their prognostic and causal implications.
Discussion:
- High D-dimer may represent an overwhelmed fibrinolytic system attempting to clear lung fibrin and necrotic tissue.
- Recent studies suggest that enhanced fibrinolytic activity could benefit critically ill patients with respiratory failure.
- Conversely, the fibrinolytic system can be exploited by the virus, necessitating antifibrinolytic strategies.
Key Insights:
- A clinical paradox exists: plasmin formation can be both beneficial and detrimental in COVID-19.
- The role of the fibrinolytic system is context-dependent, hinging on the specific stage and presentation of the disease.
- Timing of intervention targeting the fibrinolytic system is paramount for patient outcomes.
Outlook:
- Further research is needed to elucidate the precise mechanisms governing fibrinolysis in COVID-19.
- Developing targeted therapies that modulate fibrinolytic activity based on disease progression is a promising avenue.
- Understanding the temporal dynamics of fibrinolysis will be key to optimizing treatment strategies for COVID-19 patients.
Abstract:
The COVID-19 pandemic has provided many challenges in the field of thrombosis and hemostasis. Among these is a novel form of coagulopathy that includes exceptionally high levels of D-dimer. D-dimer is a marker of poor prognosis, but does this also imply a causal relationship? These spectacularly raised D-dimer levels may actually signify the failing attempt of the fibrinolytic system to remove fibrin and necrotic tissue from the lung parenchyma, being consumed or overwhelmed in the process. Indeed, recent studies suggest that increasing fibrinolytic activity might offer hope for patients with critical disease and severe respiratory failure. However, the fibrinolytic system can also be harnessed by coronavirus to promote infectivity and where antifibrinolytic measures would also seem appropriate. Hence, there is a clinical paradox where plasmin formation can be either deleterious or beneficial in COVID-19, but not at the same time. Hence, it all comes down to timing.
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