Defective NET clearance contributes to sustained FXII activation in COVID-19-associated pulmonary thrombo-inflammation
Hanna Englert,
Chandini Rangaswamy,
Carsten Deppermann,
Jan-Peter Sperhake,
Christoph Krisp,
Danny Schreier,
Emma Gordon,
Sandra Konrath,
Munif Haddad,
Giordano Pula,
Reiner K. Mailer,
Hartmut Schlüter,
Stefan Kluge,
Florian Langer,
Klaus Püschel,
Kosta Panousis,
Evi X. Stavrou,
Coen Maas,
Thomas Renné,
Maike Frye
Affiliations
Hanna Englert
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Chandini Rangaswamy
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Carsten Deppermann
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Jan-Peter Sperhake
Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Christoph Krisp
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Danny Schreier
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Emma Gordon
Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
Sandra Konrath
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Munif Haddad
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Giordano Pula
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Reiner K. Mailer
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Hartmut Schlüter
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Stefan Kluge
Department of Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Florian Langer
II. Medical Clinic and Polyclinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Klaus Püschel
Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Kosta Panousis
CSL Limited, BIO21 Institute, Parkville, Victoria, Australia
Evi X. Stavrou
Department of Medicine, Hematology and Oncology Division, CWRU School of Medicine, Cleveland, Ohio, USA; Department of Medicine, Section of Hematology-Oncology, Louis Stokes Veterans Administration Medical Center, Cleveland, Ohio, USA
Coen Maas
Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, University, Utrecht, the Netherlands
Thomas Renné
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Maike Frye
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Corresponding author.
Background: Coagulopathy and inflammation are hallmarks of Coronavirus disease 2019 (COVID-19) and are associated with increased mortality. Clinical and experimental data have revealed a role for neutrophil extracellular traps (NETs) in COVID-19 disease. The mechanisms that drive thrombo-inflammation in COVID-19 are poorly understood. Methods: We performed proteomic analysis and immunostaining of postmortem lung tissues from COVID-19 patients and patients with other lung pathologies. We further compared coagulation factor XII (FXII) and DNase activities in plasma samples from COVID-19 patients and healthy control donors and determined NET-induced FXII activation using a chromogenic substrate assay. Findings: FXII expression and activity were increased in the lung parenchyma, within the pulmonary vasculature and in fibrin-rich alveolar spaces of postmortem lung tissues from COVID-19 patients. In agreement with this, plasmaaac acafajföeFXII activation (FXIIa) was increased in samples from COVID-19 patients. Furthermore, FXIIa colocalized with NETs in COVID-19 lung tissue indicating that NETs accumulation leads to FXII contact activation in COVID-19. We further showed that an accumulation of NETs is partially due to impaired NET clearance by extracellular DNases as DNase substitution improved NET dissolution and reduced FXII activation in vitro. Interpretation: Collectively, our study supports that the NET/FXII axis contributes to the pathogenic chain of procoagulant and proinflammatory responses in COVID-19. Targeting both NETs and FXIIa may offer a potential novel therapeutic strategy. Funding: This study was supported by the European Union (840189), the Werner Otto Medical Foundation Hamburg (8/95) and the German Research Foundation (FR4239/1-1, A11/SFB877, B08/SFB841 and P06/KFO306).
