PB0592 - Altered Fibrin Network Structure and Fibrinolysis in Intensive Care Unit Patients with COVID-19, Not Entirely Explaining the Increased Risk of Thrombosis

Monday, July 11, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Judith J. de Vries, MSc

PhD student
Department of Hematology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
Rotterdam, Zuid-Holland, Netherlands

Co-Author(s)

Chantal Visser, MD

PhD candidate, MD
Department of Hematology, Erasmus MC, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
Rotterdam, Zuid-Holland, Netherlands
LG

Lotte Geers

Student
Department of Hematology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
Rotterdam, Zuid-Holland, Netherlands
JS

Johan A. Slotman

Scientist
Optical Imaging Center, Department of Pathology, Erasmus MC, University Medical Center Rotterdam
Rotterdam, Zuid-Holland, Netherlands
Nv

Nadine D. van Kleef

Research technician
University Medical Center Utrecht
Utrecht, Utrecht, Netherlands
Coen Maas, PhD

Associate Professor
Department of CDL Research, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
Utrecht, Utrecht, Netherlands
HB

Hannelore I. Bax

Medical Specialist
Department of Medical Microbiology and Infectious Diseases & Department of Internal Medicine, Erasmus MC, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
Rotterdam, Zuid-Holland, Netherlands
JM

Jelle R. Miedema

Medical Specialist
Department of Pulmonary Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
Rotterdam, Zuid-Holland, Netherlands
Ev

Eric C. van Gorp

Professor
Department of Internal Medicine & Department of Viroscience, Erasmus MC, Erasmus Medical Center Rotterdam, Rotterdam, the Netherlands
Rotterdam, Zuid-Holland, Netherlands
MG

Marco Goeijenbier

Post-doc
Department of Viroscience & Department of Adult Intensive Care, Erasmus MC, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
Rotterdam, Zuid-Holland, Netherlands
Jv

Johannes P. van den Akker

Medical Specialist
Department of Adult Intensive Care, Erasmus Medical Center Rotterdam, Rotterdam, the Netherlands
Rotterdam, Zuid-Holland, Netherlands
HE

Henrik Endeman

Medical Specialist
Department of Adult Intensive Care, Erasmus Medical Center Rotterdam, Rotterdam, the Netherlands
Rotterdam, Zuid-Holland, Netherlands
DR

Dingeman C. Rijken

Associate Professor
Department of Hematology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
Rotterdam, Zuid-Holland, Netherlands
MK

Marieke J.H.A. Kruip

Associate professor, hematologist, MD, PhD
Department of Hematology, Erasmus MC, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
Rotterdam, Zuid-Holland, Netherlands
Moniek P.M. de Maat, PhD

Professor
Department of Hematology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
Rotterdam, Zuid-Holland, Netherlands

Background: SARS-CoV-2 infection is associated with an increased incidence of thrombosis.

Aims: By studying the fibrin network structure of COVID-19 patients, we aimed to unravel pathophysiological mechanisms that contribute to this increased risk of thrombosis. This may contribute to optimal prevention and treatment of COVID-19 related thrombosis.

Methods: In this case-control study, we collected plasma samples from intensive care unit (ICU) patients with COVID-19, with and without confirmed thrombosis, between April and December 2020. Additionally, we collected plasma from COVID-19 patients admitted to general wards without thrombosis, from ICU patients with pneumococcal infection, and from healthy controls. Fibrin fiber diameters and fibrin network density were quantified in plasma clots imaged with stimulated emission depletion (STED) microscopy and confocal microscopy. Finally, we determined the sensitivity to fibrinolysis. Ethical approval was obtained and written informed consent was obtained or an opt-out procedure was in place.

Results: COVID-19 ICU patients (n=37) and ICU patients with pneumococcal disease (n=7) showed significantly higher fibrin network densities and longer plasma clot lysis times than healthy controls (n=7) (Figure 1). No differences were observed between COVID-19 ICU patients with and without thrombosis, or ICU patients with pneumococcal infection. At a second time point, after thrombosis or at a similar time point in patients without thrombosis, we observed thicker fibers and longer lysis times in COVID-19 ICU patients with thrombosis (n=19) than in COVID-19 ICU patients without thrombosis (n=18).

Conclusion(s): Our results suggest that severe COVID-19 is associated with a changed fibrin network structure and decreased susceptibility to fibrinolysis. Since these changes were not exclusive to COVID-19 patients, they may not explain the increased thrombosis risk.