Early SARS-CoV-2 infection: Platelet-neutrophil complexes and platelet function.

Area of Science:

• Hematology
• Immunology
• Infectious Diseases

Background:

• Conflicting reports exist on platelet activity in COVID-19 patients.
• Platelet dysfunction may contribute to thromboembolic complications in COVID-19.

Purpose of the Study:

• To evaluate platelet reactivity in patients with moderate COVID-19 at early disease stages.
• To investigate platelet activation and interactions with neutrophils in COVID-19.

Main Methods:

• Prospective analysis of 20 COVID-19 patients, 55 SARS-CoV-2-negative controls, and 15 healthy subjects.
• Assessed platelet reactivity using aggregometry and flow cytometry.
• Analyzed platelet-neutrophil complexes and neutrophil adhesion receptor expression.

Main Results:

• COVID-19 patients exhibited significantly impaired platelet aggregation and GPIIb/IIIa activation.
• No evidence of in vivo platelet preactivation or exhaustion was observed.
• Elevated circulating platelet-neutrophil complexes were found in COVID-19 patients.
• Upregulation of CD11b and CD66b on neutrophils was noted in COVID-19 patients.

Conclusions:

• Early-stage moderate COVID-19 is characterized by reduced platelet responsiveness but increased platelet-neutrophil complexes.
• Platelet-neutrophil interactions may occur in COVID-19 independently of prior platelet activation.