Complex Pattern of Platelet Activation/Reactivity After SARS-CoV-2 Infection.

Area of Science:

• Hematology
• Virology
• Thrombosis Research

Background:

• COVID-19 and long COVID are linked to thromboembolic events.
• The precise role of platelets in these complications remains unclear.
• Platelet activation may stem from direct viral interaction or inflammatory responses.

Purpose of the Study:

• To review and evaluate methodologies for assessing platelet function after SARS-CoV-2 exposure.
• To clarify the role of platelets in COVID-19-associated thrombosis.

Main Methods:

• Literature review and critical evaluation of studies on platelet function in COVID-19.
• Analysis of diverse methodologies, including soluble marker assays, aggregation studies, and in vitro experiments.
• Assessment of platelet reactivity to various agonists and viral interactions.

Main Results:

• Conflicting results exist regarding platelet status due to methodological variations.
• Evidence suggests elevated soluble markers of platelet activation (e.g., P-selectin, PF4) and increased platelet aggregation in COVID-19 patients.
• Platelets from COVID-19 patients show altered reactivity to agonists, though some studies report reduced fibrinogen receptor activation.

Conclusions:

• Despite methodological challenges and variable results, platelets are confirmed to play a significant role in thrombotic complications following SARS-CoV-2 infection.
• Further standardization of platelet function assays is needed for clearer insights.