9
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      COVID-19 Sepsis: Pathogenesis and Endothelial Molecular Mechanisms Based on “Two-Path Unifying Theory” of Hemostasis and Endotheliopathy-Associated Vascular Microthrombotic Disease, and Proposed Therapeutic Approach with Antimicrothrombotic Therapy

      review-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          COVID-19 sepsis is characterized by acute respiratory distress syndrome (ARDS) as a consequence of pulmonary tropism of the virus and endothelial heterogeneity of the host. ARDS is a phenotype among patients with multiorgan dysfunction syndrome (MODS) due to disseminated vascular microthrombotic disease (VMTD). In response to the viral septicemia, the host activates the complement system which produces terminal complement complex C5b-9 to neutralize pathogen. C5b-9 causes pore formation on the membrane of host endothelial cells (ECs) if CD59 is underexpressed. Also, viral S protein attraction to endothelial ACE2 receptor damages ECs. Both affect ECs and provoke endotheliopathy. Disseminated endotheliopathy activates two molecular pathways: inflammatory and microthrombotic. The former releases inflammatory cytokines from ECs, which lead to inflammation. The latter initiates endothelial exocytosis of unusually large von Willebrand factor (ULVWF) multimers and FVIII from Weibel–Palade bodies. If ADAMTS13 is insufficient, ULVWF multimers activate intravascular hemostasis of ULVWF path. In activated ULVWF path, ULVWF multimers anchored to damaged endothelial cells recruit circulating platelets and trigger microthrombogenesis. This process produces “microthrombi strings” composed of platelet-ULVWF complexes, leading to endotheliopathy-associated VMTD (EA-VMTD). In COVID-19, microthrombosis initially affects the lungs per tropism causing ARDS, but EA-VMTD may orchestrate more complex clinical phenotypes, including thrombotic thrombocytopenic purpura (TTP)-like syndrome, hepatic coagulopathy, MODS and combined micro-macrothrombotic syndrome. In this pandemic, ARDS and pulmonary thromboembolism (PTE) have often coexisted. The analysis based on two hemostatic theories supports ARDS caused by activated ULVWF path is EA-VMTD and PTE caused by activated ULVWF and TF paths is macrothrombosis. The thrombotic disorder of COVID-19 sepsis is consistent with the notion that ARDS is virus-induced disseminated EA-VMTD and PTE is in-hospital vascular injury-related macrothrombosis which is not directly  related to viral pathogenesis. The pathogenesis-based therapeutic approach is discussed for the treatment of EA-VMTD with antimicrothrombotic regimen and the potential need of anticoagulation therapy for coinciding macrothrombosis in comprehensive COVID-19 care.

          Related collections

          Most cited references157

          • Record: found
          • Abstract: found
          • Article: not found

          Pulmonary Vascular Endothelialitis, Thrombosis, and Angiogenesis in Covid-19

          Progressive respiratory failure is the primary cause of death in the coronavirus disease 2019 (Covid-19) pandemic. Despite widespread interest in the pathophysiology of the disease, relatively little is known about the associated morphologic and molecular changes in the peripheral lung of patients who die from Covid-19.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: found
            Is Open Access

            Clinical characteristics of 113 deceased patients with coronavirus disease 2019: retrospective study

            Abstract Objective To delineate the clinical characteristics of patients with coronavirus disease 2019 (covid-19) who died. Design Retrospective case series. Setting Tongji Hospital in Wuhan, China. Participants Among a cohort of 799 patients, 113 who died and 161 who recovered with a diagnosis of covid-19 were analysed. Data were collected until 28 February 2020. Main outcome measures Clinical characteristics and laboratory findings were obtained from electronic medical records with data collection forms. Results The median age of deceased patients (68 years) was significantly older than recovered patients (51 years). Male sex was more predominant in deceased patients (83; 73%) than in recovered patients (88; 55%). Chronic hypertension and other cardiovascular comorbidities were more frequent among deceased patients (54 (48%) and 16 (14%)) than recovered patients (39 (24%) and 7 (4%)). Dyspnoea, chest tightness, and disorder of consciousness were more common in deceased patients (70 (62%), 55 (49%), and 25 (22%)) than in recovered patients (50 (31%), 48 (30%), and 1 (1%)). The median time from disease onset to death in deceased patients was 16 (interquartile range 12.0-20.0) days. Leukocytosis was present in 56 (50%) patients who died and 6 (4%) who recovered, and lymphopenia was present in 103 (91%) and 76 (47%) respectively. Concentrations of alanine aminotransferase, aspartate aminotransferase, creatinine, creatine kinase, lactate dehydrogenase, cardiac troponin I, N-terminal pro-brain natriuretic peptide, and D-dimer were markedly higher in deceased patients than in recovered patients. Common complications observed more frequently in deceased patients included acute respiratory distress syndrome (113; 100%), type I respiratory failure (18/35; 51%), sepsis (113; 100%), acute cardiac injury (72/94; 77%), heart failure (41/83; 49%), alkalosis (14/35; 40%), hyperkalaemia (42; 37%), acute kidney injury (28; 25%), and hypoxic encephalopathy (23; 20%). Patients with cardiovascular comorbidity were more likely to develop cardiac complications. Regardless of history of cardiovascular disease, acute cardiac injury and heart failure were more common in deceased patients. Conclusion Severe acute respiratory syndrome coronavirus 2 infection can cause both pulmonary and systemic inflammation, leading to multi-organ dysfunction in patients at high risk. Acute respiratory distress syndrome and respiratory failure, sepsis, acute cardiac injury, and heart failure were the most common critical complications during exacerbation of covid-19.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Complement associated microvascular injury and thrombosis in the pathogenesis of severe COVID-19 infection: A report of five cases

              Acute respiratory failure and a systemic coagulopathy are critical aspects of the morbidity and mortality characterizing infection with severe acute respiratory distress syndrome-associated coronavirus-2 (SARS-CoV-2), the etiologic agent of Coronavirus disease 2019 (COVID-19). We examined skin and lung tissues from 5 patients with severe COVID-19 characterized by respiratory failure (n=5) and purpuric skin rash (n=3). The pattern of COVID-19 pneumonitis was predominantly a pauci-inflammatory septal capillary injury with significant septal capillary mural and luminal fibrin deposition and permeation of the inter-alveolar septa by neutrophils. No viral cytopathic changes were observed and the diffuse alveolar damage (DAD) with hyaline membranes, inflammation, and type II pneumocyte hyperplasia, hallmarks of classic ARDS, were not prominent. These pulmonary findings were accompanied by significant deposits of terminal complement components C5b-9 (membrane attack complex), C4d, and mannose binding lectin (MBL)-associated serine protease (MASP)2, in the microvasculature, consistent with sustained, systemic activation of the alternative and lectin-based complement pathways. The purpuric skin lesions similarly showed a pauci-inflammatory thrombogenic vasculopathy, with deposition of C5b-9 and C4d in both grossly involved and normally-appearing skin. In addition, there was co-localization of COVID-19 spike glycoproteins with C4d and C5b-9 in the inter-alveolar septa and the cutaneous microvasculature of two cases examined. In conclusion, at least a subset of sustained, severe COVID-19 may define a type of catastrophic microvascular injury syndrome mediated by activation of complement pathways and an associated procoagulant state. It provides a foundation for further exploration of the pathophysiologic importance of complement in COVID-19, and could suggest targets for specific intervention.
                Bookmark

                Author and article information

                Journal
                Vasc Health Risk Manag
                Vasc Health Risk Manag
                vhrm
                vhriskman
                Vascular Health and Risk Management
                Dove
                1176-6344
                1178-2048
                01 June 2021
                2021
                : 17
                : 273-298
                Affiliations
                [1 ]Department of Medicine, University of California Irvine School of Medicine , Irvine, CA, USA
                Author notes
                Correspondence: Jae C Chang 6 Via Castilla Unit B, Laguna Woods, CA, 92637, USATel +1-949-943-9988 Email jaec@uci.edu
                Author information
                http://orcid.org/0000-0002-9401-7684
                Article
                299357
                10.2147/VHRM.S299357
                8179800
                34103921
                b7489146-d06b-4735-91eb-36c8ea29645d
                © 2021 Chang.

                This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License ( http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms ( https://www.dovepress.com/terms.php).

                History
                : 27 December 2020
                : 24 March 2021
                Page count
                Figures: 6, Tables: 12, References: 157, Pages: 26
                Funding
                Funded by: no support of funding;
                There is no support of funding in research, preparation and publication of this article.
                Categories
                Review

                Cardiovascular Medicine
                acute respiratory distress syndrome; ards,adamts13,endotheliopathy,macrothrombosis; microthrombosis,multiorgan dysfunction syndrome; mods

                Comments

                Comment on this article