PB0079 - Inhibitory potential of anticoagulant and antiplatelet agents on COVID-19-induced NETs release

Sunday, July 10, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

José D. Oliveira, PhD

PhD student
University of Campinas
Campinas, Sao Paulo, Brazil

Co-Author(s)

Leticia Queiroz da Silva, Doctor of Science

University of Campinas
Campinas, Sao Paulo, Brazil
GD

Gislaine Damiani

Professor
University of Campinas
Campinas, Sao Paulo, Brazil
AS

Ana Santos

Mastering Student
University of Campinas
Campinas, Sao Paulo, Brazil
BJ

Bruna Jacintho

Mastering Student
University of Campinas
Campinas, Sao Paulo, Brazil
CV

Camila Vaz

Phd student
University of Campinas
Campinas, Sao Paulo, Brazil
GM

Gabriela Mesquita

Mastering Student
University of Campinas
campinas, Sao Paulo, Brazil
JA

Joyce Annichino-Bizzacchi

Supervisor and professor
Hemostasis and Thrombosis Laboratory, Hematology and Hemotherapy Center, University of Campinas (UNICAMP)
Campinas, Sao Paulo, Brazil
BM

Bruna Mazetto

Biologist
University of Campinas
Campinas, Sao Paulo, Brazil
EV

Erich V. Vinicius de Paula

Professor
University of Campinas
Campinas, Sao Paulo, Brazil
FO

Fernanda A. Orsi

Hematologist
University of São Paulo Medical School
São Paulo, Sao Paulo, Brazil

Background: Neutrophil extracellular traps (NETs) release is the one of the main mechanisms behind hypercoagulability and disease severity in severe acute respiratory syndromes. The identification of drugs capable of inhibiting this pathological mechanism is mandatory.

Aims: Neutrophil extracellular traps (NETs) release is the one of the main mechanisms behind hypercoagulability and disease severity in severe acute respiratory syndromes. The identification of drugs capable of inhibiting this pathological mechanism is mandatory.

Methods: Healthy neutrophils (20x103/well) were stimulated with phorbol myristate acetate (PMA) or sera from severe COVID-19 patients (n=16) in the presence or absence of dipyridamole (10uM), aspirin (1mM) and heparin (50ug/mL). Neutrophils nuclei were stained with nuclear red and incubated with a medium containing the non-permeable cell membrane marker Sytox Green. Cell images were obtained using IncuCyte ZOOM and the number of cells that suffered netosis was monitored over time. NETs release was determined after 1 hour of incubation and the percentage of NETs was calculated dividing the number of green cells by the total number of cells per well.

Results: COVID-19 induced NETs was lower in neutrophils pretreated with heparin (median 2.6%, IQR 2.6-2.9) than in non-treated neutrophils (median 3.6%, IQR 3.2-4.0, P< 0.0001). Pretreatment with dipyridamole and aspirin did not change the effect of COVID-19 sera in inducing NETs. A similar pattern of inhibition was observed with PMA stimulation, in which heparin decreased NETs by 3 times (NETs after PMA 43.2% and NETs after PMA and heparin 14.8%) while dipyridamole and aspirin did not significantly affect the release of PMA-induced NETs (Figure 1). Figure 2 illustrates the identification of NETs.

Conclusion(s): Heparin was capable of inhibiting “in vitro” NETs release induced by COVID-19, while dipyridamole and aspirin had no significant effect on this process. Such findings are in line with evidence that heparin use can improve COVID-19 prognosis.