PB0071 - The impact of COVID-19 and venovenous ECMO on the generation and characteristics of extracellular vesicles

Sunday, June 25, 2023

18:30 – 19:30 ET

Room: Exhibition

Co-Author(s)

Ludwig Traby, MD PhD

Consultant in Internal Medicine
Medical University of Vienna, Department of Medicine I
Vienna, Wien, Austria

Presenting Author(s)

Lisbeth Eischer, MD

MD
Department of Medicine I, Medical University of Vienna, Vienna, Austria
Vienna, Wien, Austria

Co-Author(s)

MK

Marietta Kollars

Lab Technician
Medical University of Vienna, Department of Medicine I
Vienna, Wien, Austria
MK

Manuel Kussmann

Resident
Medical University of Vienna, Department of Medicine I
Vienna, Wien, Austria
NB

Nina Buchtele

Resident
Medical University of Vienna, Department of Medicine I
Vienna, Wien, Austria
MW

Matthias Weiss-Tessbach

Resident
Medical University of Vienna
Vienna, Wien, Austria
TS

Thomas Staudinger

Specialits in Intensive Care Medicine
Medical University of Vienna, Department of Medicine I
Vienna, Wien, Austria
HB

Heinz Burgmann

Professor for Infectious Diseases and Tropical Medicine
Medical University of Vienna, Department of Medicine I
Vienna, Wien, Austria
OR

Oliver Robak

Specialist in Intensive Care Medicine
Medical University of Vienna, Department of Medicine I
Vienna, Wien, Austria
PK

Paul A. Kyrle

Professor
Medical University of Vienna, Department of Medicine I
Vienna, Wien, Austria
Sabine Eichinger, MD

Professor
Medical University of Vienna, Department of Medicine I
Vienna, Wien, Austria

Background: COVID-19 causes coagulation activation and inflammation. Patients with COVID-19-associated ARDS are managed by venovenous extracorporeal membrane oxygenation (ECMO). Extracellular vesicles (EV) are markers of coagulopathy and inflammation in COVID-19. Data on EV in COVID-19 patients on ECMO are limited.

Aims: To evaluate the number and characteristics of EV in COVID-19 patients on ECMO.

Methods: We studied 49 adult COVID-19 patients on ECMO and 35 age-and sex matched healthy controls (hc). Blood was collected at time point A (ECMO day 1) and time point B (ECMO day 10). Number and surface characteristics of EV were determined in plasma by flow cytometry. Values are given as median (25th, 75th percentile). Unpaired t-tests of logarithmized parameters were used for statistical testing. The study was approved by the local Ethics Committee. Patients or legal representatives provided written informed consent if possible.

Results: Total EV numbers and numbers of EV originating from platelets were significantly higher in COVID-19 patients on ECMO compared with hc, with no significant difference of EV numbers between time point A and B (Table 1, Figure 1). About 80% of all EV were platelet-derived. Number of EV originating from endothelial cells did not significantly differ between patients and hc. Numbers of tissue factor-positive EV, as a marker of coagulation activation, were significantly lower in patients compared with hc, likely resulting from anticoagulant treatment. Number of uPAR-positive EV, as a fibrinolysis marker, were higher in patients compared with hc. Numbers of uPAR-positive EV were significantly higher at time point A compared with B. Numbers of ICAM-1-positive EV, as an inflammation marker, were significantly lower in patients compared with hc, which could be due to immunomodulating treatment in patients.

Conclusion(s): Numbers and surface characteristics of EV are affected in COVID-19 patients on ECMO, and could be explored as markers of disease and intervention.