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1.
JCI Insight ; 6(18)2021 09 22.
Article in English | MEDLINE | ID: covidwho-1435144

ABSTRACT

Neutrophils provide a critical line of defense in immune responses to various pathogens, inflicting self-damage upon transition to a hyperactivated, procoagulant state. Recent work has highlighted proinflammatory neutrophil phenotypes contributing to lung injury and acute respiratory distress syndrome (ARDS) in patients with coronavirus disease 2019 (COVID-19). Here, we use state-of-the art mass spectrometry-based proteomics and transcriptomic and correlative analyses as well as functional in vitro and in vivo studies to dissect how neutrophils contribute to the progression to severe COVID-19. We identify a reinforcing loop of both systemic and neutrophil intrinsic IL-8 (CXCL8/IL-8) dysregulation, which initiates and perpetuates neutrophil-driven immunopathology. This positive feedback loop of systemic and neutrophil autocrine IL-8 production leads to an activated, prothrombotic neutrophil phenotype characterized by degranulation and neutrophil extracellular trap (NET) formation. In severe COVID-19, neutrophils directly initiate the coagulation and complement cascade, highlighting a link to the immunothrombotic state observed in these patients. Targeting the IL-8-CXCR-1/-2 axis interferes with this vicious cycle and attenuates neutrophil activation, degranulation, NETosis, and IL-8 release. Finally, we show that blocking IL-8-like signaling reduces severe acute respiratory distress syndrome of coronavirus 2 (SARS-CoV-2) spike protein-induced, human ACE2-dependent pulmonary microthrombosis in mice. In summary, our data provide comprehensive insights into the activation mechanisms of neutrophils in COVID-19 and uncover a self-sustaining neutrophil-IL-8 axis as a promising therapeutic target in severe SARS-CoV-2 infection.


Subject(s)
COVID-19/metabolism , Interleukin-8/metabolism , Lung/immunology , Neutrophils/immunology , SARS-CoV-2 , Thrombosis/etiology , Animals , COVID-19/complications , COVID-19/pathology , Humans , Lung/pathology , Mice , Neutrophil Activation , Neutrophils/pathology , Phenotype , Thrombosis/pathology
2.
GMS J Med Educ ; 38(1): Doc25, 2021.
Article in English | MEDLINE | ID: covidwho-1110244

ABSTRACT

Background: In light of the COVID-19 pandemic and resulting demand for innovative hospital management we organized an interactive online discussion for medical students and healthcare professionals about hospital management during the crisis. Objective: The event offered an opportunity to learn from a hospital crisis management. We looked at how this new online format compares to a traditional discussion event. Methods: We used an online platform with four guests, a moderator and about 100 attendees. During the event we gathered demographic facts through an interactive questionnaire tool and an extensive evaluation afterwards. Results: The event was rated with an overall grade of 1.4 (Likert from 1 to 6, 1 best grade; SD 0.5) and participants agreed that this format should be organized again (1.2; SD 0.5). 70% of audience members preferred the online format of the event. Due to the high volume, only about 30% (total n~35) of the questions posed by the audience were addressed. Conclusion: Firstly, most participants preferred the event to be online, contrary to our expectation. Secondly, the handling of the amount of individual questions posed significant challenges. Finally, the number of attendees and questions suggested a continuing demand among students and physicians for further education regarding hospital management, especially regarding COVID-19. These findings also require a critical look at future formats and topics of podium discussions in medical education. The online format might be a good alternative to face-to-face lectures.


Subject(s)
COVID-19/epidemiology , Education, Distance/organization & administration , Education, Medical/organization & administration , Emergencies , Hospital Administration/education , Adult , Female , Humans , Male , Pandemics , SARS-CoV-2
3.
J Thromb Haemost ; 19(2): 574-581, 2021 02.
Article in English | MEDLINE | ID: covidwho-939789

ABSTRACT

OBJECTIVE: Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to severe pneumonia, but also thrombotic complications and non-pulmonary organ failure. Recent studies suggest intravascular neutrophil activation and subsequent immune cell-triggered immunothrombosis as a central pathomechanism linking the heterogenous clinical picture of coronavirus disease 2019 (COVID-19). We sought to study whether immunothrombosis is a pathognomonic factor in COVID-19 or a general feature of (viral) pneumonia, as well as to better understand its upstream regulation. APPROACH AND RESULTS: By comparing histopathological specimens of SARS-CoV-2 with influenza-affected lungs, we show that vascular neutrophil recruitment, NETosis, and subsequent immunothrombosis are typical features of severe COVID-19, but less prominent in influenza pneumonia. Activated neutrophils were typically found in physical association with monocytes. To explore this further, we combined clinical data of COVID-19 cases with comprehensive immune cell phenotyping and bronchoalveolar lavage fluid scRNA-seq data. We show that a HLADRlow CD9low monocyte population expands in severe COVID-19, which releases neutrophil chemokines in the lungs, and might in turn explain neutrophil expansion and pulmonary recruitment in the late stages of severe COVID-19. CONCLUSIONS: Our data underline an innate immune cell axis causing vascular inflammation and immunothrombosis in severe SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , Immunity, Innate , Influenza, Human/immunology , Lung/immunology , Neutrophils/immunology , Thrombosis/immunology , Vasculitis/immunology , COVID-19/diagnosis , COVID-19/virology , Diagnosis, Differential , Host-Pathogen Interactions , Humans , Influenza, Human/diagnosis , Influenza, Human/virology , Lung/pathology , Lung/virology , Neutrophils/virology , Predictive Value of Tests , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Thrombosis/virology , Vasculitis/virology
4.
Circulation ; 142(12): 1176-1189, 2020 09 22.
Article in English | MEDLINE | ID: covidwho-696368

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome corona virus 2 infection causes severe pneumonia (coronavirus disease 2019 [COVID-19]), but the mechanisms of subsequent respiratory failure and complicating renal and myocardial involvement are poorly understood. In addition, a systemic prothrombotic phenotype has been reported in patients with COVID-19. METHODS: A total of 62 subjects were included in our study (n=38 patients with reverse transcriptase polymerase chain reaction-confirmed COVID-19 and n=24 non-COVID-19 controls). We performed histopathologic assessment of autopsy cases, surface marker-based phenotyping of neutrophils and platelets, and functional assays for platelet, neutrophil functions, and coagulation tests, as well. RESULTS: We provide evidence that organ involvement and prothrombotic features in COVID-19 are linked by immunothrombosis. We show that, in COVID-19, inflammatory microvascular thrombi are present in the lung, kidney, and heart, containing neutrophil extracellular traps associated with platelets and fibrin. Patients with COVID-19 also present with neutrophil-platelet aggregates and a distinct neutrophil and platelet activation pattern in blood, which changes with disease severity. Whereas cases of intermediate severity show an exhausted platelet and hyporeactive neutrophil phenotype, patients severely affected with COVID-19 are characterized by excessive platelet and neutrophil activation in comparison with healthy controls and non-COVID-19 pneumonia. Dysregulated immunothrombosis in severe acute respiratory syndrome corona virus 2 pneumonia is linked to both acute respiratory distress syndrome and systemic hypercoagulability. CONCLUSIONS: Taken together, our data point to immunothrombotic dysregulation as a key marker of disease severity in COVID-19. Further work is necessary to determine the role of immunothrombosis in COVID-19.


Subject(s)
Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , Respiratory Insufficiency/etiology , Betacoronavirus/genetics , Betacoronavirus/isolation & purification , Blood Coagulation Disorders/diagnosis , Blood Coagulation Disorders/etiology , Blood Platelets/cytology , Blood Platelets/metabolism , Blood Platelets/pathology , COVID-19 , Case-Control Studies , Coronavirus Infections/complications , Coronavirus Infections/pathology , Coronavirus Infections/virology , Extracellular Traps/metabolism , Humans , Kidney/pathology , Lung/pathology , Neutrophils/cytology , Neutrophils/metabolism , Neutrophils/pathology , Pandemics , Phenotype , Platelet Activation , Pneumonia, Viral/complications , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Respiratory Insufficiency/diagnosis , SARS-CoV-2 , Severity of Illness Index , Thrombosis/complications , Thrombosis/diagnosis
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