The vascular endothelium: the cornerstone of organ dysfunction in severe SARS-CoV-2 infection.
TL;DR: In this article, the role of endothelial cells (ECs) in vascular dysfunction, immunothrombosis, and inflammation in severe SARS-CoV-2 infections has been emphasized.
Abstract: In severe SARS-CoV-2 infections, emerging data including recent histopathological studies have emphasized the crucial role of endothelial cells (ECs) in vascular dysfunction, immunothrombosis, and inflammation.Histopathological studies have evidenced direct viral infection of ECs, endotheliitis with diffuse endothelial inflammation, and micro- and macrovascular thrombosis both in the venous and arterial circulations. Venous thrombotic events, particularly pulmonary embolism, with elevated D-dimer and coagulation activation are highly prevalent in COVID-19 patients. The pro-inflammatory cytokine storm, with elevated levels of interleukin-6 (IL-6), IL-2 receptor, and tumor necrosis factor-α, could also participate in endothelial dysfunction and leukocyte recruitment in the microvasculature. COVID-19-induced endotheliitis may explain the systemic impaired microcirculatory function in different organs in COVID-19 patients. Ongoing trials directly and indirectly target COVID-19-related endothelial dysfunctions: i.e., a virus-cell entry using recombinant angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS-2) blockade, coagulation activation, and immunomodulatory therapies, such as anti-IL-6 strategies. Studies focusing on endothelial dysfunction in COVID-19 patients are warranted as to decipher their precise role in severe SARS-CoV-2 infection and organ dysfunction and to identify targets for further interventions.
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TL;DR: The vascular endothelium is an active paracrine, endocrine, and Endothelial cell infection and endotheliitis in COVID-19 and recruitment of immune cells can result in widespread endothelial dysfunction associated with apoptosis.
4,855 citations
Baylor College of Medicine1, Veterans Health Administration2, Icahn School of Medicine at Mount Sinai3, Primary Children's Hospital4, Royal Free Hospital5, University of Massachusetts Boston6, Rush University Medical Center7, Imperial College London8, University of Colorado Denver9, Leeds Teaching Hospitals NHS Trust10, University Health Network11, University of Miami12, Genentech13, Hoffmann-La Roche14, University of California, San Diego15
TL;DR: In this paper, a randomized trial involving hospitalized patients with severe Covid-19 pneumonia, the use of tocilizumab did not result in significantly better clinical status or lower mortality than placebo at 28 days.
Abstract: Background Coronavirus disease 2019 (Covid-19) is associated with immune dysregulation and hyperinflammation, including elevated interleukin-6 levels. The use of tocilizumab, a monoclonal antibody against the interleukin-6 receptor, has resulted in better outcomes in patients with severe Covid-19 pneumonia in case reports and retrospective observational cohort studies. Data are needed from randomized, placebo-controlled trials. Methods In this phase 3 trial, we randomly assigned patients who were hospitalized with severe Covid-19 pneumonia in a 2:1 ratio receive a single intravenous infusion of tocilizumab (at a dose of 8 mg per kilogram of body weight) or placebo. Approximately one quarter of the participants received a second dose of tocilizumab or placebo 8 to 24 hours after the first dose. The primary outcome was clinical status at day 28 on an ordinal scale ranging from 1 (discharged or ready for discharge) to 7 (death) in the modified intention-to-treat population, which included all the patients who had received at least one dose of tocilizumab or placebo. Results Of the 452 patients who underwent randomization, 438 (294 in the tocilizumab group and 144 in the placebo group) were included in the primary and secondary analyses. The median value for clinical status on the ordinal scale at day 28 was 1.0 (95% confidence interval [CI], 1.0 to 1.0) in the tocilizumab group and 2.0 (non-ICU hospitalization without supplemental oxygen) (95% CI, 1.0 to 4.0) in the placebo group (between-group difference, -1.0; 95% CI, -2.5 to 0; P = 0.31 by the van Elteren test). In the safety population, serious adverse events occurred in 103 of 295 patients (34.9%) in the tocilizumab group and in 55 of 143 patients (38.5%) in the placebo group. Mortality at day 28 was 19.7% in the tocilizumab group and 19.4% in the placebo group (weighted difference, 0.3 percentage points (95% CI, -7.6 to 8.2; nominal P = 0.94). Conclusions In this randomized trial involving hospitalized patients with severe Covid-19 pneumonia, the use of tocilizumab did not result in significantly better clinical status or lower mortality than placebo at 28 days. (Funded by F. Hoffmann-La Roche and the Department of Health and Human Services; COVACTA ClinicalTrials.gov number, NCT04320615.).
666 citations
Posted Content•
TL;DR: Nearly 50% COVID-19 patients could not reach obvious clinical and radiological remission within 10 days after hospitalization, and the patients with male sex, anorexia and no fever on admission predicted poor efficacy.
Abstract: South Australia is presently in the throes of major changes to its regulatory system governing land use, development of land and the development of planning policy against which development assessment decisions are to be made. Eventually the planning and development control system established under the Development Act 1993 (SA) will be replaced by a new system implemented by the Planning, Development and Infrastructure Act 2016 (SA) (the new Act).
568 citations
25 Sep 2020
TL;DR: Venous thromboembolism is frequently observed in patients with coronavirus disease 2019 (COVID‐19), however, reported VTE rates differ substantially.
Abstract: Background Venous thromboembolism (VTE) is frequently observed in patients with coronavirus disease 2019 (COVID-19). However, reported VTE-rates differ substantially. Objectives We aimed at evaluating available data and estimating the prevalence of VTE in COVID-19 patients. Methods We conducted a systematic literature search (MEDLINE, EMBASE, WHO COVID-19 database) to identify studies reporting VTE-rates in COVID-19 patients. Studies with suspected high risk of bias were excluded from quantitative synthesis. Pooled outcome rates were obtained within a random effects meta-analysis. Subgroup analyses were performed for different settings (intensive care unit (ICU) vs. non-ICU hospitalization and screening vs. no screening) and the association of D-dimer levels and VTE-risk was explored. Results Eighty-six studies (33,970 patients) were identified and 66 (28,173 patients, mean age: 62.6 years, 60% men, 20% ICU-patients) were included in quantitative analysis. The overall VTE-prevalence estimate was 14.1% (95%CI 11.6-16.9), 40.3% (95%CI 27.0-54.3) with ultrasound-screening and 9.5% (95%CI 7.5-11.7) without screening. Subgroup analysis revealed high heterogeneity, with a VTE-prevalence of 7.9% (95%CI 5.1-11.2) in non-ICU and 22.7% (95%CI 18.1-27.6) in ICU patients. Prevalence of pulmonary embolism (PE) in non-ICU and ICU patients was 3.5% (95%CI 2.2-5.1) and 13.7% (95%CI 10.0-17.9). Patients developing VTE had higher D-dimer levels (weighted mean difference 3.26 µg/ml (95%CI 2.76-3.77) than non-VTE patients. Conclusion VTE occurs in 22.7% of patients with COVID-19 in the ICU, but VTE risk is also increased in non-ICU hospitalized patients. Patients developing VTE had higher D-dimer levels. Studies evaluating thromboprophylaxis strategies in patients with COVID-19 are needed to improve prevention of VTE.
322 citations
TL;DR: The literature on the association between COVID-19 and neurological manifestations is reviewed, evidence from preclinical research suggesting that SARS-CoV-2 could be responsible for many of these manifestations is presented, and the biological pathways that could underlie each neurological symptom are summarized.
Abstract: As the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic spreads, it is becoming increasingly evident that coronavirus disease 2019 (COVID-19) is not limited to the respiratory system, and that other organs can be affected. In particular, virus-related neurological manifestations are being reported more and more frequently in the scientific literature. In this article, we review the literature on the association between COVID-19 and neurological manifestations, present evidence from preclinical research suggesting that SARS-CoV-2 could be responsible for many of these manifestations, and summarize the biological pathways that could underlie each neurological symptom. Understanding the mechanisms that lead to neurological manifestations in patients with COVID-19 and how these manifestations correlate with clinical outcomes will be instrumental in guiding the optimal use of targeted therapeutic strategies.
318 citations
References
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TL;DR: The epidemiological and clinical characteristics of novel coronavirus (2019-nCoV)-infected pneumonia in Wuhan, China, and hospital-associated transmission as the presumed mechanism of infection for affected health professionals and hospitalized patients are described.
Abstract: Importance In December 2019, novel coronavirus (2019-nCoV)–infected pneumonia (NCIP) occurred in Wuhan, China. The number of cases has increased rapidly but information on the clinical characteristics of affected patients is limited. Objective To describe the epidemiological and clinical characteristics of NCIP. Design, Setting, and Participants Retrospective, single-center case series of the 138 consecutive hospitalized patients with confirmed NCIP at Zhongnan Hospital of Wuhan University in Wuhan, China, from January 1 to January 28, 2020; final date of follow-up was February 3, 2020. Exposures Documented NCIP. Main Outcomes and Measures Epidemiological, demographic, clinical, laboratory, radiological, and treatment data were collected and analyzed. Outcomes of critically ill patients and noncritically ill patients were compared. Presumed hospital-related transmission was suspected if a cluster of health professionals or hospitalized patients in the same wards became infected and a possible source of infection could be tracked. Results Of 138 hospitalized patients with NCIP, the median age was 56 years (interquartile range, 42-68; range, 22-92 years) and 75 (54.3%) were men. Hospital-associated transmission was suspected as the presumed mechanism of infection for affected health professionals (40 [29%]) and hospitalized patients (17 [12.3%]). Common symptoms included fever (136 [98.6%]), fatigue (96 [69.6%]), and dry cough (82 [59.4%]). Lymphopenia (lymphocyte count, 0.8 × 109/L [interquartile range {IQR}, 0.6-1.1]) occurred in 97 patients (70.3%), prolonged prothrombin time (13.0 seconds [IQR, 12.3-13.7]) in 80 patients (58%), and elevated lactate dehydrogenase (261 U/L [IQR, 182-403]) in 55 patients (39.9%). Chest computed tomographic scans showed bilateral patchy shadows or ground glass opacity in the lungs of all patients. Most patients received antiviral therapy (oseltamivir, 124 [89.9%]), and many received antibacterial therapy (moxifloxacin, 89 [64.4%]; ceftriaxone, 34 [24.6%]; azithromycin, 25 [18.1%]) and glucocorticoid therapy (62 [44.9%]). Thirty-six patients (26.1%) were transferred to the intensive care unit (ICU) because of complications, including acute respiratory distress syndrome (22 [61.1%]), arrhythmia (16 [44.4%]), and shock (11 [30.6%]). The median time from first symptom to dyspnea was 5.0 days, to hospital admission was 7.0 days, and to ARDS was 8.0 days. Patients treated in the ICU (n = 36), compared with patients not treated in the ICU (n = 102), were older (median age, 66 years vs 51 years), were more likely to have underlying comorbidities (26 [72.2%] vs 38 [37.3%]), and were more likely to have dyspnea (23 [63.9%] vs 20 [19.6%]), and anorexia (24 [66.7%] vs 31 [30.4%]). Of the 36 cases in the ICU, 4 (11.1%) received high-flow oxygen therapy, 15 (41.7%) received noninvasive ventilation, and 17 (47.2%) received invasive ventilation (4 were switched to extracorporeal membrane oxygenation). As of February 3, 47 patients (34.1%) were discharged and 6 died (overall mortality, 4.3%), but the remaining patients are still hospitalized. Among those discharged alive (n = 47), the median hospital stay was 10 days (IQR, 7.0-14.0). Conclusions and Relevance In this single-center case series of 138 hospitalized patients with confirmed NCIP in Wuhan, China, presumed hospital-related transmission of 2019-nCoV was suspected in 41% of patients, 26% of patients received ICU care, and mortality was 4.3%.
16,635 citations
TL;DR: It is demonstrated that SARS-CoV-2 uses the SARS -CoV receptor ACE2 for entry and the serine protease TMPRSS2 for S protein priming, and it is shown that the sera from convalescent SARS patients cross-neutralized Sars-2-S-driven entry.
15,362 citations
"The vascular endothelium: the corne..." refers background in this paper
...Therefore, cell invasion depends on both ACE2 expression and the availability of the protease transmembrane protease serine 2 (TMPRSS-2), or other proteases, to cleave the viral spike [23]....
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...in vitro and is efficient to block SARS-CoV-2 entry into the cells [23]....
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TL;DR: Although high fever was associated with the development of ARDS, it was also associated with better outcomes among patients with ARDS and treatment with methylprednisolone may be beneficial for patients who develop ARDS.
Abstract: Importance Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that was first reported in Wuhan, China, and has subsequently spread worldwide. Risk factors for the clinical outcomes of COVID-19 pneumonia have not yet been well delineated. Objective To describe the clinical characteristics and outcomes in patients with COVID-19 pneumonia who developed acute respiratory distress syndrome (ARDS) or died. Design, Setting, and Participants Retrospective cohort study of 201 patients with confirmed COVID-19 pneumonia admitted to Wuhan Jinyintan Hospital in China between December 25, 2019, and January 26, 2020. The final date of follow-up was February 13, 2020. Exposures Confirmed COVID-19 pneumonia. Main Outcomes and Measures The development of ARDS and death. Epidemiological, demographic, clinical, laboratory, management, treatment, and outcome data were also collected and analyzed. Results Of 201 patients, the median age was 51 years (interquartile range, 43-60 years), and 128 (63.7%) patients were men. Eighty-four patients (41.8%) developed ARDS, and of those 84 patients, 44 (52.4%) died. In those who developed ARDS, compared with those who did not, more patients presented with dyspnea (50 of 84 [59.5%] patients and 30 of 117 [25.6%] patients, respectively [difference, 33.9%; 95% CI, 19.7%-48.1%]) and had comorbidities such as hypertension (23 of 84 [27.4%] patients and 16 of 117 [13.7%] patients, respectively [difference, 13.7%; 95% CI, 1.3%-26.1%]) and diabetes (16 of 84 [19.0%] patients and 6 of 117 [5.1%] patients, respectively [difference, 13.9%; 95% CI, 3.6%-24.2%]). In bivariate Cox regression analysis, risk factors associated with the development of ARDS and progression from ARDS to death included older age (hazard ratio [HR], 3.26; 95% CI 2.08-5.11; and HR, 6.17; 95% CI, 3.26-11.67, respectively), neutrophilia (HR, 1.14; 95% CI, 1.09-1.19; and HR, 1.08; 95% CI, 1.01-1.17, respectively), and organ and coagulation dysfunction (eg, higher lactate dehydrogenase [HR, 1.61; 95% CI, 1.44-1.79; and HR, 1.30; 95% CI, 1.11-1.52, respectively] and D-dimer [HR, 1.03; 95% CI, 1.01-1.04; and HR, 1.02; 95% CI, 1.01-1.04, respectively]). High fever (≥39 °C) was associated with higher likelihood of ARDS development (HR, 1.77; 95% CI, 1.11-2.84) and lower likelihood of death (HR, 0.41; 95% CI, 0.21-0.82). Among patients with ARDS, treatment with methylprednisolone decreased the risk of death (HR, 0.38; 95% CI, 0.20-0.72). Conclusions and Relevance Older age was associated with greater risk of development of ARDS and death likely owing to less rigorous immune response. Although high fever was associated with the development of ARDS, it was also associated with better outcomes among patients with ARDS. Moreover, treatment with methylprednisolone may be beneficial for patients who develop ARDS.
6,335 citations
"The vascular endothelium: the corne..." refers background in this paper
...However, in a cohort observational study including 201 patients in China, treatment with methylprednisone was beneficial to patients with ARDS [78]....
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...However, as noticed by Leisman et al. [29], in COVID-19 patients, plasmatic concentrations of cytokines, especially IL-6, are much lower than in typical hyper-inflammatory ARDS or in CRS and should be distinguished from them [30, 31]....
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...A recent observational Chinese study of 31 severe COVID-19 patients including 11 treated by corticosteroids found no association between therapy and outcomes in patients without ARDS [77]....
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...ACE2: Angiotensin-converting enzyme 2; Ag: Antigen; ARDS: Acute respiratory distress syndrome; CRS: Cytokine release syndrome; DIC: Disseminated intravascular coagulation; ECs: Endothelial cells; FDP: Fibrin degradation product; ICU: Intensive care unit; IL-1β : Interleukin 1β; IL2R: Interleukin 2 receptor; IL-6: Interleukin 6; IL-6R: Interleukin 6 receptor; ISTH: International Society on Thrombosis and Haemostasis; MCP1: Monocyte chemoattractant; MERS-CoV: Middle East respiratory syndrome coronavirus; PAI 1: Plasminogen activator inhibitor 1; rACE2: Recombinant angiotensin-converting enzyme 2; SARS-CoV: Severe acute respiratory syndrome coronavirus; SARS-Cov-2: Severe acute respiratory syndrome coronavirus 2; TMPRSS-2: Transmembrane protease serine 2; TNF- α: Tumor necrosis factor-α; vWF: von Willebrand factor; vWF Ag: von Willebrand factor antigen...
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...Given the fundamental role of ECs in maintaining homeostasis, vascular permeability, and blood rheology, EC dysfunction may actively participate in thrombo-inflammatory processes that ultimately result in COVID-19 vasculopathy, ventilation-perfusion mismatch, and a clinical phenotype of refractory ARDS [18]....
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TL;DR: The vascular endothelium is an active paracrine, endocrine, and Endothelial cell infection and endotheliitis in COVID-19 and recruitment of immune cells can result in widespread endothelial dysfunction associated with apoptosis.
4,855 citations
"The vascular endothelium: the corne..." refers background in this paper
...Authors suggest that COVID-19-induced endotheliitis may explain the systemic impaired microcirculatory function in different organs in COVID-19 patients [14]....
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...the crucial role of ECs in vascular dysfunction, inflammation, and (immuno) thrombosis [14, 15]....
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TL;DR: ACE2 is abundantly present in humans in the epithelia of the lung and small intestine, which might provide possible routes of entry for the SARS‐CoV.
Abstract: Severe acute respiratory syndrome (SARS) is an acute infectious disease that spreads mainly via the respiratory route. A distinct coronavirus (SARS-CoV) has been identified as the aetiological agent of SARS. Recently, a metallopeptidase named angiotensin-converting enzyme 2 (ACE2) has been identified as the functional receptor for SARS-CoV. Although ACE2 mRNA is known to be present in virtually all organs, its protein expression is largely unknown. Since identifying the possible route of infection has major implications for understanding the pathogenesis and future treatment strategies for SARS, the present study investigated the localization of ACE2 protein in various human organs (oral and nasal mucosa, nasopharynx, lung, stomach, small intestine, colon, skin, lymph nodes, thymus, bone marrow, spleen, liver, kidney, and brain). The most remarkable finding was the surface expression of ACE2 protein on lung alveolar epithelial cells and enterocytes of the small intestine. Furthermore, ACE2 was present in arterial and venous endothelial cells and arterial smooth muscle cells in all organs studied. In conclusion, ACE2 is abundantly present in humans in the epithelia of the lung and small intestine, which might provide possible routes of entry for the SARS-CoV. This epithelial expression, together with the presence of ACE2 in vascular endothelium, also provides a first step in understanding the pathogenesis of the main SARS disease manifestations.
4,714 citations
"The vascular endothelium: the corne..." refers background in this paper
...ACE2 has been found in arterial and venous endothelial cells in various human tissues, including the oral and nasal mucosa, lung, small intestine, colon, skin, lymph nodes, thymus, bone marrow, spleen, kidney, and brain [21]....
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