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ABSTRACT: Background
Conflicting results have been reported on platelet activity ex vivo and responsiveness in vitro among patients with COVID-19 with or without thromboembolic complications.Objectives
To assess platelet reactivity in patients with moderate disease at early stages of COVID-19.Methods
We performed a prospective, descriptive analysis of 100 consecutive patients presenting with suspected SARS-CoV-2 infection at University Medical Center Freiburg during the first or second wave of the pandemic. Following polymerase chain reaction testing and compliance with study inclusion criteria, 20 SARS-CoV-2-positive and 55 SARS-CoV-2-negative patients (serving as patient controls) were enrolled. In addition, 15 healthy subjects were included. Platelet reactivity was assessed using whole-blood impedance aggregometry and flow cytometry in response to various agonists.Results
Platelet aggregation was significantly impaired in the patients with COVID-19 compared with that in the patient controls or healthy subjects. The reduced platelet responsiveness in the patients with COVID-19 was associated with impaired activation of GPIIb/IIIa (αIIbβ3). In contrast, low expression of P-selectin at baseline and intact secretion upon stimulation in vitro suggest that no preactivation in vivo, leading to "exhausted" platelets, had occurred. The proportion of circulating platelet-neutrophil complexes was significantly higher in the patients with COVID-19 (mean ± SD, 41% ± 13%) than in the patient controls (18% ± 7%; 95% CI, 11.1-34.1; P = .0002) or healthy subjects (17% ± 4%; 95% CI, 13.8-33.8; P < .0001). An analysis of neutrophil adhesion receptors revealed upregulation of CD11b (α-subunit of αMβ2) and CD66b (CEACAM8) but not of CD162 (PSGL-1) in the patients with COVID-19.Conclusion
Despite reduced platelet responsiveness, platelet-neutrophil complexes are increased at early stages of moderate disease. Thus, this cellular interaction may occur during COVID-19 without preceding platelet activation.
SUBMITTER: Rieder M
PROVIDER: S-EPMC9783187 | biostudies-literature | 2023 Jan
REPOSITORIES: biostudies-literature
Research and practice in thrombosis and haemostasis 20221223 1
<h4>Background</h4>Conflicting results have been reported on platelet activity <i>ex vivo</i> and responsiveness <i>in vitro</i> among patients with COVID-19 with or without thromboembolic complications.<h4>Objectives</h4>To assess platelet reactivity in patients with moderate disease at early stages of COVID-19.<h4>Methods</h4>We performed a prospective, descriptive analysis of 100 consecutive patients presenting with suspected SARS-CoV-2 infection at University Medical Center Freiburg during t ...[more]