Impaired coagulation, liver dysfunction and COVID-19: Discovering an intriguing relationship

Area of Science:

• Hepatology and Infectious Diseases
• Vascular Biology and Thrombosis
• Immunology and Inflammation

Background:

• Coronavirus disease 2019 (COVID-19) presents significant global health challenges.
• Hepatic alterations, including decompensation and failure, are observed in COVID-19 patients, correlating with increased mortality.
• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to liver injury through various mechanisms, with secondary injury being more common than primary viral hepatitis.

Purpose of the Study:

• To explore the mechanisms of liver injury in COVID-19 patients.
• To investigate the link between SARS-CoV-2 infection, systemic inflammation, coagulopathy, and hepatic dysfunction.
• To summarize current understanding of COVID-19-associated liver damage and its relationship with thrombotic events.

Main Methods:

• Review of existing literature on COVID-19, liver injury, and coagulopathy.
• Analysis of proposed mechanisms including systemic inflammation, hypoxic injury, drug toxicity, and viral cytopathic effects.
• Examination of data on vascular complications, hemostasis dysregulation, and laboratory markers in COVID-19 patients.

Main Results:

• Liver damage in COVID-19 is predominantly secondary, driven by systemic inflammation rather than direct viral cytopathic effects.
• SARS-CoV-2 infection triggers endothelial damage and a prothrombotic state, leading to increased venous and arterial thrombosis, including pulmonary embolism, stroke, and peripheral arterial disease.
• COVID-19-associated coagulopathy is characterized by low platelets, prolonged prothrombin time, elevated D-dimer, high von Willebrand factor, and impaired fibrinolysis, contributing to "immuno-thromboinflammation."
• Liver dysfunction and coagulopathy frequently coexist, with evidence suggesting microvascular thrombosis as a potential mediator of liver damage.

Conclusions:

• Liver injury in COVID-19 is complex, often resulting from systemic inflammation and coagulopathy rather than direct viral attack on hepatocytes.
• The interplay between "immuno-thromboinflammation," endothelial dysfunction, and coagulopathy significantly contributes to both liver damage and thrombotic events in COVID-19.
• Understanding these mechanisms is crucial for managing COVID-19 patients and mitigating risks of hepatic and vascular complications.