Platelets in COVID-19 disease: friend, foe, or both?

Area of Science:

• Immunology
• Hematology
• Pulmonology

Background:

• COVID-19 is linked to immuno-thrombosis, characterized by platelet activation and coagulopathy.
• Antiplatelet therapy is used to prevent thrombotic events in COVID-19, but clinical trials show limited impact on mortality.
• This paradox suggests complex platelet roles beyond hemostasis in COVID-19.

Purpose of the Study:

• To review evidence on platelets' protective functions in endothelial barrier integrity during inflammation, particularly in the lungs.
• To explore how inhibiting platelet function might affect beneficial roles in COVID-19 immuno-thrombosis.
• To guide the development of targeted antiplatelet strategies for COVID-19.

Main Methods:

• Literature review of clinical trials and experimental studies on platelet function in COVID-19.
• Analysis of platelet roles in host defense and endothelial barrier maintenance.
• Examination of the balance between pro-thrombotic and protective platelet activities.

Main Results:

• Platelets exhibit protective properties in maintaining endothelial barrier integrity, especially in pulmonary circulation.
• Inhibiting platelet function might counteract these protective effects, diminishing clinical benefits.
• The pro-thrombotic aspect of platelet activity in COVID-19 needs to be balanced against their barrier-protective role.

Conclusions:

• Understanding the dual role of platelets in COVID-19 is crucial for optimizing antiplatelet therapy.
• Future strategies should aim to inhibit pro-thrombotic platelet activity while preserving their barrier-protective functions.
• Targeted antiplatelet therapies are needed to effectively manage immuno-thrombosis in COVID-19 without compromising host defense.