Mechanisms of severe acute respiratory syndrome coronavirus-induced acute lung injury

D-dimer level is associated with the severity of COVID-19

INTRODUCTION

Abnormal coagulation function has been demonstrated to be involved in the disease progression of COVID-19. However, the association between D-dimer levels and the severity of COVID-19 is not clear. The study was aimed to investigate the association between D-dimer levels and the severity of COVID-19 based on a cohort study and meta-analysis.

MATERIALS AND METHODS

Demographic and clinical data of all confirmed cases with COVID-19 on admission to Tongji Hospital from January 27 to March 5, 2020, were collected and analyzed, and coagulation function parameters were described and compared between patients with severe infection and those with non-severe infection. Cohort studies reporting risk estimates for the D-dimer and severity of COVID-19 association were searched and included to perform a meta-analysis.

RESULTS

In our cohort study, patients with severe disease were more likely to exhibit dysregulated coagulation function, and a significantly higher D-dimer level (median 1.8 μg/ml [interquartile range 0.9-4.6] vs 0.5 [0.3-1.1], p < 0.001) was found in severe cases than the mild ones, on admission. In the meta-analysis of 13 cohort studies (including the current study), patients with severe disease had an increase in mean D-dimer value by 0.91 (95% confidence interval, 0.51-1.31, p < 0.001) μg/ml compared to those with non-severe disease, and odds of severe infection was associated with D-dimer greater than 0.5 μg/ml (odds ratio = 5.78, 95% confidence interval, 2.16-15.44, p < 0.001) on admission.

CONCLUSIONS

Patients with severe COVID-19 have a higher level of D-dimer than those with non-severe disease, and D-dimer greater than 0.5 μg/ml is associated with severe infection in patients with COVID-19.

Clinical characteristics and outcomes of critically ill patients with COVID-19 in a tertiary community hospital in upstate New York

Background: There are limited reports describing critically ill COVID-19 patients in the state of New York. Methods: We conducted a retrospective analysis of 32 adult critically ill patients admitted to a community hospital in upstate New York, between 14 March and 12 April 2020. We collected demographic, laboratory, ventilator and treatment data, which were analyzed and clinical outcomes tabulated. Results: 32 patients admitted to the intensive care unit (ICU) were included, with mean (±SD) follow-up duration 21 ± 7 days. Mean (±SD) age was 62.2 ± 11.2 years, and 62.5% were men. 27 (84.4%) of patients had one or more medical co-morbidities. The mean (±SD) duration of symptoms was 6.6 (±4.4) days before presentation, with cough (81.3%), dyspnea (68.7%), and fever (65.6%) being the most common. 23 (71.9%) patients received invasive mechanical ventilation. 5 (15.6%) died, 11 (34.4%) were discharged home, and 16 (50%) remained hospitalized, 8 (25%) of which were still in ICU. Mean (±SD) length of ICU stay was 10.2 (±7.7) days, and mean (±SD) length of hospital stay was 14.8 (±7.7) days. Conclusion: Majority of patients were of older age and with medical comorbidities. With adequate resource utilization, mortality of critically ill COVID-19 patients may not be as high as previously suggested. Abbreviations: ACE-i: Angiotensin converting enzyme inhibitor; ARB: Angiotensin receptor blocker; ARDS: Acute Respiratory Distress Syndrome; BiPAP: Bilevel positive airway pressure; CABG: Coronary artery bypass graft; CFR: Case fatality rate; COVID-19: Coronavirus disease 19; CPAP: Continuous positive airway pressure; CRP: C - Reactive Protein; CT: Computed tomography; DVT: Deep vein thrombosis; ECMO: Extra Corporeal Membrane Oxygenation; ESICM: European Society of Intensive Care Medicine; FiO2: Fraction of inspired O2; HFNC: High Flow Nasal Cannula; HITF: Hypoxia-Inducible Transcription Factor; IBM: International Business Machines; ICU: Intensive Care Unit; IL: Interleukin; IMV: Invasive Mechanical Ventilation; IQR: Interquartile Range; ISTH: International Society of Thrombosis Hemostasis; NIV: Non Invasive Ventilation; NY: New York; PAI: Plasminogen activator inhibitor; PaO2: partial pressure of arterial oxygen; PCV: Pressure Control Ventilation; PEEP: Positive End Expiratory Pressure; RGH: Rochester General Hospital; RRH: Rochester Regional Health; RT-PCR: Reverse transcriptase polymerase chain reaction; RSV: Respiratory Syncytial virus; SARS-CoV-2: Severe Acute Respiratory Syndrome Coronavirus 2; SD: Standard Deviation; STEMI: ST segment elevation myocardial infarction; TNF: Tumor necrosis factor; USA: USA; VTE: Venous thromboembolism.

Coronavirus Historical Perspective, Disease Mechanisms, and Clinical Outcomes: JACC Focus Seminar

The emergence of a new coronavirus disease (coronavirus disease 2019 [COVID-19]) has raised global concerns regarding the health and safety of a vulnerable population. Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) incites a profound inflammatory response leading to tissue injury and organ failure. COVID-19 is characterized by the bidirectional relationship between inflammation and thrombosis. The clinical syndrome is propelled by inflammation producing acute lung injury, large-vessel thrombosis, and in situ microthrombi that may contribute to organ failure. Myocardial injury is common, but true myocarditis is rare. Elderly patients, those with established cardiovascular disease, and mechanically ventilated patients face the highest mortality risk. Therapies for COVID-19 are evolving. The antiviral drug remdesivir, dexamethasone, transfusion of convalescent plasma, and use of antithrombotic therapy are promising. Most require additional prospective studies. Although most patients recover, those who survive severe illness may experience persistent physical and psychological disabilities.

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Severe acute respiratory syndrome coronavirus 2 infection (COVID-19) is a global pandemic affecting millions of people worldwide.

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Clinical sequelae result largely from an intense inflammatory response triggering large-vessel and microvascular thrombosis.

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No therapy has been universally effective for COVID-19, but systemic anticoagulation, remdesivir, and corticosteroids hold promise.

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Long-term sequelae of COVID-19 are variable and incompletely defined, but physical and psychological disabilities can persist.

Severe COVID-19 Pneumonia in a 30-Year-Old Woman in the 36th Week of Pregnancy Treated with Postpartum Extracorporeal Membrane Oxygenation

Patient: Female, 30-year-old

Final Diagnosis: Severe COVID-19 pneumonia

Symptoms: Dyspena

Medication: —

Clinical Procedure: Extracorporeal membrane oxygenation

Specialty: Critical Care Medicine • Infectious Diseases

COVID-19 Infection-Related Coagulopathy and Viscoelastic Methods: A Paradigm for Their Clinical Utility in Critical Illness

Hypercoagulability and thrombosis remain a challenge to diagnose and treat in severe COVID-19 infection. The ability of conventional global coagulation tests to accurately reflect in vivo hypo- or hypercoagulability is questioned. The currently available evidence suggests that markedly increased D-dimers can be used in identifying COVID-19 patients who may need intensive care unit (ICU) admission and close monitoring or not. Viscoelastic methods (VMs), like thromboelastography (TEG) and rotational thromboelastometry (ROTEM), estimate the dynamics of blood coagulation. The evaluation of coagulopathy by VMs in severe COVID-19 infection seems an increasingly attractive option. Available evidence supports that COVID-19 patients with acute respiratory failure suffer from severe hypercoagulability rather than consumptive coagulopathy often associated with fibrinolysis shutdown. However, the variability in definitions of both the procoagulant profile and the clinical outcome assessment, in parallel with the small sample sizes in most of these studies, do not allow the establishment of a clear association between the hypercoagulable state and thrombotic events. VMs can effectively provide insight into the pathophysiology of coagulopathy, detecting the presence of hypercoagulability in critically ill COVID-19 patients. However, it remains unknown whether the degree of coagulopathy can be used in order to predict the outcome, establish a diagnosis or guide anticoagulant therapy.

Prolonged prothrombin time at admission predicts poor clinical outcome in COVID-19 patients

BACKGROUND

The prognostic value of coagulation disorder in coronavirus disease 2019 (COVID-19) patients should be demonstrated.

AIM

To investigate the abnormalities of coagulation parameters in the patients with COVID-19 and their prognostic values.

METHODS

Consecutive patients admitted in the isolation ward of Renmin Hospital of Wuhan University from January 31 to February 5, 2020 with confirmed COVID-19 were included. The primary outcomes were death and survival as of March 11. Demographics, vital signs, comorbidities and laboratory tests were collected and compared between those who died and survivors. Logistic regression analysis for prognostic factors was performed. Kaplan-Meier analysis was used to compare the estimated survival rate between patients with prolonged prothrombin time and normal prothrombin time.

RESULTS

The total number of patients with confirmed COVID-19 who were enrolled was 213. The median age was 62 years, and 95 patients (44.6%) were men. Fifty-one patients were critical (23.9%), 79 patients were severe (37.1%) and 83 patients were moderate (39%). As of March 11, 2020, 99 patients were discharged (46.5%), 79 patients (37.1%) stayed in the hospital and 35 patients (16.2%) died. Median time to death was 6 (4-8) d, while median hospital stay was 32 (22-36) d in survivors (P < 0.001). More men (P = 0.002) and elderly patients (P < 0.001) were found in the group of those who died. The respiration rate at admission was higher in the group of those who died (P < 0.001). The incidences of hypertension (P = 0.028), cerebrovascular disease (P < 0.001), chronic kidney disease (P = 0.02) and chronic obstructive pulmonary disease (P < 0.001) were higher in the group of those who died. Platelet count was decreased in the group of those who died (P = 0.002) whereas prothrombin time (P < 0.001), activated partial thromboplastin time (P = 0.033), concentration of D-dimer (P < 0.001) and fibrin degradation products (P < 0.001) were increased in the group of those who died. Prothrombin time [odds ratio (OR): 2.19, P = 0.004], respiration rate (OR: 1.223, P < 0.001), age (OR: 1.074, P < 0.001) and fibrin degradation products concentration (OR: 1.02, P = 0.014) were predictors of death. The survival rate was significantly lower in patients with prolonged prothrombin time compare to those with normal prothrombin time (P < 0.001).

CONCLUSION

Prothrombin time, concentration of fibrin degradation products, respiration rate and age were predictive factors for clinical outcomes of COVID-19 patients.

COVID-19 Patients: A Systematic Review and Meta-Analysis of Laboratory Findings, Comorbidities, and Clinical Outcomes Comparing Medical Staff versus the General Population

This review compared coronavirus disease 2019 (COVID-19) laboratory findings, comorbidities, and clinical outcomes in patients from the general population versus medical staff to aid diagnosis of COVID-19 in a more timely, efficient, and accurate way. Electronic databases were searched up to 23rd March, 2020. The initial search yielded 6,527 studies. Following screening, 24 studies were included [18 studies (11,564 cases) of confirmed COVID-19 cases in the general public, and 6 studies (394 cases) in medical staff] in this review. Significant differences were observed in white blood cell counts (p < 0.001), lymphocyte counts (p < 0.001), platelet counts (p = 0.04), procalcitonin levels (p < 0.001), lactate dehydrogenase levels (p < 0.001), and creatinine levels (p = 0.03) when comparing infected medical staff with the general public. The mortality rate was higher in the general population than in medical staff (8% versus 2%). This review showed that during the early stages of COVID-19, laboratory findings alone may not be significant predictors of infection and may just accompany increasing C-reactive protein levels, erythrocyte sedimentation rates, and lactate dehydrogenase levels. In the symptomatic stage, the lymphocyte and platelet counts tended to decrease. Elevated D-dimer fibrin degradation product was associated with poor prognosis.

Preceding infection and risk of stroke: An old concept revived by the COVID-19 pandemic

Anecdotal reports and clinical observations have recently emerged suggesting a relationship between COVID-19 disease and stroke, highlighting the possibility that infected individuals may be more susceptible to cerebrovascular events. In this review we draw on emerging studies of the current pandemic and data from earlier, viral epidemics, to describe possible mechanisms by which SARS-CoV-2 may influence the prevalence of stroke, with a focus on the thromboinflammatory pathways, which may be perturbed. Some of these potential mechanisms are not novel but are, in fact, long-standing hypotheses linking stroke with preceding infection that are yet to be confirmed. The current pandemic may present a renewed opportunity to better understand the relationship between infection and stroke and possible underlying mechanisms.

Hypoxemia in COVID-19 patients: An hypothesis

The current SARS-Cov-2 virus pandemic challenges critical care physicians and other caregivers to find effective treatment for desperately ill patients - especially those with sudden and extreme hypoxemia. Unlike patients with other forms of Acute Respiratory Distress Syndrome, these patients do not exhibit increased lung stiffness or dramatic dyspnea., even in the presence of arterial blood oxygen levels lower than that seen normally in mixed venous blood. Urgent intubation and mechanical ventilation with high inflation pressures and raised inhaled oxygen concentration have proved unhelpful or worse, but why? Our Hypothesis is that sudden opening of a previously undetected probe-patent foramen ovale (PPFO) may explain this mystery. As hypoxemia without acidosis is a rather weak stimulus of dyspnea or increased ventilation, and opening of such an intracardiac shunt would not worsen lung mechanical properties, the absence of dramatic symptom changes would not be surprising. We point out the high frequency of PFO both in life and at autopsy, and the physiological evidence of large shunt fractions found in Covid-19 patients. Published evidence of hypercoagulability and abundant evidence of pulmonary emboli found at autopsy are in accord with our hypothesis, as they would contribute to raised pressure in the pulmonary arteries and right heart chambers, potentially causing a shunt to open. We review the interaction between viral corona spike protein and ACE-2 receptors present on the surface of alveolar lining cells, and contribution to hypercoagulabilty caused by the spike protein. Search for an open PFO after a large drop in arterial oxygen saturation can be performed at the bedside with a variety of well-established techniques including bedside echocardiography, nitrogen washout test, and imaging studies. Potential treatments might include balloon or patch closure of the shunt, and various drug treatments to lower pulmonary vascular resistance.

COVID-19-associated coagulopathy: An exploration of mechanisms

An ongoing global pandemic of viral pneumonia (coronavirus disease [COVID-19]), due to the virus SARS-CoV-2, has infected millions of people and remains a threat to many more. Most critically ill patients have respiratory failure and there is an international effort to understand mechanisms and predictors of disease severity. Coagulopathy, characterized by elevations in D-dimer and fibrin(ogen) degradation products (FDPs), is associated with critical illness and mortality in patients with COVID-19. Furthermore, increasing reports of microvascular and macrovascular thrombi suggest that hemostatic imbalances may contribute to the pathophysiology of SARS-CoV-2 infection. We review the laboratory and clinical findings of patients with COVID-19-associated coagulopathy, and prior studies of hemostasis in other viral infections and acute respiratory distress syndrome. We hypothesize that an imbalance between coagulation and inflammation may result in a hypercoagulable state. Although thrombosis initiated by the innate immune system is hypothesized to limit SARS-CoV-2 dissemination, aberrant activation of this system can cause endothelial injury resulting in loss of thromboprotective mechanisms, excess thrombin generation, and dysregulation of fibrinolysis and thrombosis. The role various components including neutrophils, neutrophil extracellular traps, activated platelets, microparticles, clotting factors, inflammatory cytokines, and complement play in this process remains an area of active investigation and ongoing clinical trials target these different pathways in COVID-19.

Evaluation of variation in D-dimer levels among COVID-19 and bacterial pneumonia: a retrospective analysis

In the recent outbreak of novel coronavirus infection worldwide, the risk of thrombosis and bleeding should be concerned. We aimed to observe the dynamic changes of D-dimer levels during disease progression to evaluate their value for thrombosis. In this study, we report the clinical and laboratory results of 57 patients with confirmed COVID-19 pneumonia and 46 patients with confirmed community-acquired bacterial pneumonia (CAP). And their concentrations of D-dimer, infection-related biomarkers, and conventional coagulation were retrospectively analyzed. The Padua prediction score is used to identify patients at high risk for venous thromboembolism (VTE). The results found that, on admission, both in COVID-19 patients and CAP patients, D-dimer levels were significantly increased, and compared with CAP patients, D-dimer levels were higher in COVID-19 patients (P  < 0.05). Besides, we found that in COVID-19 patients, D-dimer were related with markers of inflammation, especially with hsCRP (R = 0.426, P < 0.05). However, there was low correlation between VTE score and D-dimer levels (Spearman’s R = 0.264, P > 0.05) weakened the role of D-dimer in the prediction of thrombosis. After treatments, D-dimer levels decreased which was synchronous with hsCRP levels in patients with good clinical prognosis, but there were still some patients with anomalous increasing D-dimer levels after therapy. In conclusion, elevated baseline D-dimer levels are associated with inflammation but not with VTE score in COVID-19 patients, suggesting that it is unreasonable to judge whether anticoagulation is needed only according to D-dimer levels. However, the abnormal changes of D-dimer and inflammatory factors suggest that anticoagulant therapy might be needed.

Inflammation, Thrombosis, and Destruction: The Three-Headed Cerberus of Trauma- and SARS-CoV-2-Induced ARDS

Physical trauma can be considered an unrecognized "pandemic" because it can occur anywhere and affect anyone and represents a global burden. Following severe tissue trauma, patients frequently develop acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS) despite modern surgical and intensive care concepts. The underlying complex pathophysiology of life-threatening ALI/ARDS has been intensively studied in experimental and clinical settings. However, currently, the coronavirus family has become the focus of ALI/ARDS research because it represents an emerging global public health threat. The clinical presentation of the infection is highly heterogeneous, varying from a lack of symptoms to multiple organ dysfunction and mortality. In a particular subset of patients, the primary infection progresses rapidly to ALI and ARDS. The pathophysiological mechanisms triggering and driving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced ALI/ARDS are still poorly understood. Although it is also generally unknown whether insights from trauma-induced ARDS may be readily translated to SARS-CoV-2-associated ARDS, it was still recommended to treat coronavirus-positive patients with ALI/ARDS with standard protocols for ALI/ARDS. However, this strategy was questioned by clinical scientists, because it was documented that some severely hypoxic SARS-CoV-2-infected patients exhibited a normal respiratory system compliance, a phenomenon rarely observed in ARDS patients with another underlying etiology. Therefore, coronavirus-induced ARDS was defined as a specific ARDS phenotype, which accordingly requires an adjusted therapeutic approach. These suggestions reflect previous attempts of classifying ARDS into different phenotypes that might overall facilitate ARDS diagnosis and treatment. Based on the clinical data from ARDS patients, two major phenotypes have been proposed: hyper- and hypo-inflammatory. Here, we provide a comparative review of the pathophysiological pathway of trauma-/hemorrhagic shock-induced ARDS and coronavirus-induced ARDS, with an emphasis on the crucial key points in the pathogenesis of both these ARDS forms. Therefore, the manifold available data on trauma-/hemorrhagic shock-induced ARDS may help to better understand coronavirus-induced ARDS.

COVID-19 and Respiratory System Disorders: Current Knowledge, Future Clinical and Translational Research Questions

The severe acute respiratory syndrome coronavirus-2 emerged as a serious human pathogen in late 2019, causing the disease coronavirus disease 2019 (COVID-19). The most common clinical presentation of severe COVID-19 is acute respiratory failure consistent with the acute respiratory distress syndrome. Airway, lung parenchymal, pulmonary vascular, and respiratory neuromuscular disorders all feature in COVID-19. This article reviews what is known about the effects of severe acute respiratory syndrome coronavirus-2 infection on different parts of the respiratory system, clues to understanding the underlying biology of respiratory disease, and highlights current and future translation and clinical research questions.

Coagulopathie associée au COVID-19 : les éléments essentiels pour l’anesthésiste-réanimateur

Coagulation disorders are commonly reported in patients suffering from COVID-19 pneumonia. These are associated to an increase incidence of thrombotic disorders associated with an increase mortality rate. D-Dimers concentrations > 3 μg/L, fibrinogen > 8 g/L and decreased platelets count are associated with an increased thrombotic risk. These biological markers have to be closely monitored during ICU stay. The diagnosis of pulmonary embolism could be difficult in this setting. However, it has to be evoked in case of worsening hypoxemia unexplained by other reason and/or right ventricular failure. The thrombotic risk can be scored to adapt the thromboprophylactic treatment, impaired renal function and overweight making it even more difficult.

Coagulopathy in COVID-19

The COVID-19 pandemic has become an urgent issue in every country. Based on recent reports, the most severely ill patients present with coagulopathy, and disseminated intravascular coagulation (DIC)-like massive intravascular clot formation is frequently seen in this cohort. Therefore, coagulation tests may be considered useful to discriminate severe cases of COVID-19. The clinical presentation of COVID-19-associated coagulopathy is organ dysfunction primarily, whereas hemorrhagic events are less frequent. Changes in hemostatic biomarkers represented by increase in D-dimer and fibrin/fibrinogen degradation products indicate the essence of coagulopathy is massive fibrin formation. In comparison with bacterial-sepsis-associated coagulopathy/DIC, prolongation of prothrombin time, and activated partial thromboplastin time, and decrease in antithrombin activity is less frequent and thrombocytopenia is relatively uncommon in COVID-19. The mechanisms of the coagulopathy are not fully elucidated, however. It is speculated that the dysregulated immune responses orchestrated by inflammatory cytokines, lymphocyte cell death, hypoxia, and endothelial damage are involved. Bleeding tendency is uncommon, but the incidence of thrombosis in COVID-19 and the adequacy of current recommendations regarding standard venous thromboembolic dosing are uncertain.

Coagulopathy and thromboembolic events in patients with SARS-CoV-2 infection: pathogenesis and management strategies

In October 2019, a viral infectious disease appeared in the city of Wuhan in China. A new betacoronavirus, SARS-CoV-2, has been recognized as the responsible pathogen in this infection. Although coronavirus disease is principally expressed as a pulmonary infection, critical SARS-CoV-2 infection is frequently complicated with coagulopathy, and thromboembolic events are recognizable in several patients. Dehydration, acute inflammatory condition, protracted immobilization during disease, existence of multiple cardiovascular risk factors such as diabetes, obesity or hypertension, previous coronary artery disease, ischemic stroke, peripheral artery disease are frequent comorbidities in SARS-CoV-2 hospitalized subjects, which possibly augment thrombo-embolic risk. However, other causal factors can still be identified such as unrestricted angiotensin II action, the use of immunoglobulins, an increased production of adhesion molecules able to induce vascular inflammation and endothelial activation, complement stimulation, excessive production of neutrophil extracellular traps (NETs), and increased platelet count. Low-molecular-weight heparin should be chosen as early treatment because of its anti-inflammatory action and its ability to antagonize histones and so defend the endothelium. However, several therapeutic possibilities have also been proposed such as fibrinolytic treatment, drugs that target NETs, and complement inhibition. Nevertheless, although the violence of the pandemic may suggest the use of heroic treatments to reduce the frightening mortality that accompanies SARS-CoV-2 infection, we believe that experimental treatments should only be used within approved and controlled protocols, the only ones that can provide useful and specify information on the validity of the treatments.

Coagulation Abnormalities and Thrombosis in Patients Infected With SARS-CoV-2 and Other Pandemic Viruses

The world is amid a pandemic caused by severe acute respiratory syndrome-coronavirus 2. Severe acute respiratory syndrome-coronavirus causes serious respiratory tract infections that can lead to viral pneumonia, acute respiratory distress syndrome, and death. Some patients with coronavirus disease 2019 (COVID-19) have an activated coagulation system characterized by elevated plasma levels of d-dimer-a biomarker of fibrin degradation. Importantly, high levels of D-dimer on hospital admission are associated with increased risk of mortality. Venous thromboembolism is more common than arterial thromboembolism in hospitalized COVID-19 patients. Pulmonary thrombosis and microvascular thrombosis are observed in autopsy studies, and this may contribute to the severe hypoxia observed in COVID-19 patients. It is likely that multiple systems contribute to thrombosis in COVID-19 patients, such as activation of coagulation, platelet activation, hypofibrinolysis, endothelial cell dysfunction, inflammation, neutrophil extracellular traps, and complement. Targeting these different pathways may reduce thrombosis and improve lung function in COVID-19 patients.

Coagulopathy in COVID-19: Focus on vascular thrombotic events

SARS-CoV-2 causes a phenotype of pneumonia with diverse manifestation, which is termed as coronavirus disease 2019 (COVID-19). An impressive high transmission rate allows COVID-19 conferring enormous challenge for clinicians worldwide, and developing to a pandemic level. Combined with a series of complications, a part of COVID-19 patients progress into severe cases, which critically contributes to the risk of fatality. To date, coagulopathy has been found as a prominent feature of COVID-19 and severe coagulation dysfunction may be associated with poor prognosis. Coagulopathy in COVID-19 may predispose patients to hypercoagulability-related disorders including thrombosis and even fatal vascular events. Inflammatory storm, uncontrolled inflammation-mediated endothelial injury and renin angiotensin system (RAS) dysregulation are the potential mechanisms. Ongoing efforts made to develop promising therapies provide several potential strategies for hypercoagulability in COVID-19. In this review, we introduce the clinical features of coagulation and the increased vascular thrombotic risk conferred by coagulopathy according to present reports about COVID-19. The potential underlying mechanisms and emerging therapeutic avenues are discussed, emphasizing an urgent need for effective interventions.

Coagulopathy of Coronavirus Disease 2019

OBJECTIVES

Recent studies have reported a high prevalence of thrombotic events in coronavirus disease 2019. However, the significance of thromboembolic complications has not been widely appreciated. The purpose of this review is to provide current knowledge of this serious problem.

DESIGN

Narrative review.

DATA SOURCES

Online search of published medical literature through PubMed using the term "COVID-19," "SARS," "acute respiratory distress syndrome," "coronavirus," "coagulopathy," "thrombus," and "anticoagulants."

STUDY SELECTION AND DATA EXTRACTION

Articles were chosen for inclusion based on their relevance to coagulopathy and thrombosis in coronavirus disease 2019, and anticoagulant therapy. Reference lists were reviewed to identify additional relevant articles.

DATA SYNTHESIS

Coronavirus disease 2019 is associated with a strikingly high prevalence of coagulopathy and venous thromboembolism that may contribute to respiratory deterioration. Monitoring coagulation variables is important, as abnormal coagulation tests are related to adverse outcomes and may necessitate adjuvant antithrombotic interventions. In the initial phase of the infection, D-dimer and fibrinogen levels are increased, while activated partial prothrombin time, prothrombin time, and platelet counts are often relatively normal. Increased D-dimer levels three times the upper limit of normal may trigger screening for venous thromboembolism. In all hospitalized patients, thromboprophylaxis using low-molecular-weight heparin is currently recommended. The etiology of the procoagulant responses is complex and thought to be a result of specific interactions between host defense mechanisms and the coagulation system. Although the coagulopathy is reminiscent of disseminated intravascular coagulation and thrombotic microangiopathy, it has features that are markedly distinct from these entities.

CONCLUSIONS

Severe acute respiratory syndrome coronavirus 2/coronavirus disease 2019 frequently induces hypercoagulability with both microangiopathy and local thrombus formation, and a systemic coagulation defect that leads to large vessel thrombosis and major thromboembolic complications, including pulmonary embolism in critically ill hospitalized patients. D-dimers and fibrinogen levels should be monitored, and all hospitalized patients should undergo thromboembolism prophylaxis with an increase in therapeutic anticoagulation in certain clinical situations.

A Pathophysiological Perspective on COVID-19's Lethal Complication: From Viremia to Hypersensitivity Pneumonitis-like Immune Dysregulation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the coronavirus responsible for our recent coronavirus disease 2019 pandemic, is driving a lung immunopathology that strongly resembles a severe form of hypersensitivity pneumonitis (HP). A review of recent Severe acute respiratory syndrome-related coronavirus (SARS-CoV) and SARS-CoV-2 medical reports, as well as described characteristics of HP, lead us to postulate a theory for SARS-CoV-2 severe disease. We propose that the novel SARS-CoV-2 can act as a trigger and substrate of an HP-like severe immune reaction especially in genetically vulnerable individuals in addition to those with immune senescence and dysregulation. Accordingly, the purpose of our letter is to shift the emphasis of concern surrounding immune activity from viral infection to an HP-like severe immune reaction. We review similarities in disease presentation between infection and allergy, relevant immunopathology, and outline phases of SARS-CoV-2 disease with perspectives on therapy and critical care. Altogether, the favored course is to begin treatments that address the disease at the earliest phase before immune dysregulation leading to uncontrolled pulmonary inflammation.

Fibrinolysis and COVID-19: A plasmin paradox

The COVID-19 pandemic has provided many challenges in the field of thrombosis and hemostasis. Among these is a novel form of coagulopathy that includes exceptionally high levels of D-dimer. D-dimer is a marker of poor prognosis, but does this also imply a causal relationship? These spectacularly raised D-dimer levels may actually signify the failing attempt of the fibrinolytic system to remove fibrin and necrotic tissue from the lung parenchyma, being consumed or overwhelmed in the process. Indeed, recent studies suggest that increasing fibrinolytic activity might offer hope for patients with critical disease and severe respiratory failure. However, the fibrinolytic system can also be harnessed by coronavirus to promote infectivity and where antifibrinolytic measures would also seem appropriate. Hence, there is a clinical paradox where plasmin formation can be either deleterious or beneficial in COVID-19, but not at the same time. Hence, it all comes down to timing.

ANDC: an early warning score to predict mortality risk for patients with Coronavirus Disease 2019

Background

Patients with severe Coronavirus Disease 2019 (COVID-19) will progress rapidly to acute respiratory failure or death. We aimed to develop a quantitative tool for early predicting mortality risk of patients with COVID-19.

Methods

301 patients with confirmed COVID-19 admitted to Main District and Tumor Center of the Union Hospital of Huazhong University of Science and Technology (Wuhan, China) between January 1, 2020 to February 15, 2020 were enrolled in this retrospective two-centers study. Data on patient demographic characteristics, laboratory findings and clinical outcomes was analyzed. A nomogram was constructed to predict the death probability of COVID-19 patients.

Results

Age, neutrophil-to-lymphocyte ratio, d-dimer and C-reactive protein obtained on admission were identified as predictors of mortality for COVID-19 patients by LASSO. The nomogram demonstrated good calibration and discrimination with the area under the curve (AUC) of 0.921 and 0.975 for the derivation and validation cohort, respectively. An integrated score (named ANDC) with its corresponding death probability was derived. Using ANDC cut-off values of 59 and 101, COVID-19 patients were classified into three subgroups. The death probability of low risk group (ANDC < 59) was less than 5%, moderate risk group (59 ≤ ANDC ≤ 101) was 5% to 50%, and high risk group (ANDC > 101) was more than 50%, respectively.

Conclusion

The prognostic nomogram exhibited good discrimination power in early identification of COVID-19 patients with high mortality risk, and ANDC score may help physicians to optimize patient stratification management.

Endothelial Dysfunction in COVID-19: Lessons Learned from Coronaviruses

Purpose of Review

To review current literature on endothelial dysfunction with previous coronaviruses, and present available data on the role of endothelial dysfunction in coronavirus disease-2019 (COVID-19) infection in terms of pathophysiology and clinical phenotype

Recent Findings

Recent evidence suggests that signs and symptoms of severe COVID-19 infection resemble the clinical phenotype of endothelial dysfunction, implicating mutual pathophysiological pathways. Dysfunction of endothelial cells is believed to mediate a variety of viral infections, including those caused by previous coronaviruses. Experience from previous coronaviruses has triggered hypotheses on the role of endothelial dysfunction in the pathophysiology of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), which are currently being tested in preclinical and clinical studies.

Summary

Endothelial dysfunction is the common denominator of multiple clinical aspects of severe COVID-19 infection that have been problematic for treating physicians. Given the global impact of this pandemic, better understanding of the pathophysiology could significantly affect management of patients.

Hemostatic abnormalities in COVID-19: A guided review

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has already taken on pandemic proportions, affecting over 213 countries in a matter of weeks. In this context, several studies correlating hemostatic disorders with the infection dynamics of the new coronavirus have emerged. These studies have shown that a portion of the patients affected by Coronavirus Disease 2019 (COVID-19) have prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT), elevated D-dimer levels and other fibrinolytic products, antithrombin (AT) activity reduced and decrease of platelet count. Based on these hallmarks, this review proposes to present possible pathophysiological mechanisms involved in the hemostatic changes observed in the pathological progression of COVID-19. In this analysis, it is pointed the relationship between the downregulation of angiotensin-converting enzyme 2 (ACE2) and storm cytokines action with the onset of hypercoagulability state, other than the clinical events involved in thrombocytopenia and hyperfibrinolysis progression.

Coagulation dysfunction in COVID-19: The interplay between inflammation, viral infection and the coagulation system

COVID-19 is a new pandemic, caused by Severe Acute Respiratory Syndrome-CoronaVirus-2 (SARS-Cov2) infection and characterized by a broad spectrum of clinical manifestations.

Inflammation and the innate immune system have been recently recognized as pivotal players in the most severe forms, characterized by significantly elevated levels of pro-inflammatory cytokines. In this setting, several studies have also reported the presence of abnormalities in coagulation parameters and platelets count, possibly identifying a subgroup of patients with poor prognosis. Some reports of full-blown thromboembolic events are emerging.

Among the possible mechanisms underlying coagulation dysfunction, the so-called "cytokine storm" seems to play a pivotal role. Other candidate factors include virus-specific mechanisms, related to the virus interaction with renin angiotensin system (RAS) and the fibrinolytic pathway, but also comorbidities affecting these patients.

Coagulation dysfunction is therefore a candidate risk factor for adverse outcomes in COVID-19 and should be carefully addressed in clinical practice.

COVID-19 coagulopathy: An in-depth analysis of the coagulation system

Background

Abnormal coagulation parameters have been reported in COVID‐19‐infected patients. Although the underlying mechanism of COVID‐19 coagulopathy remains unknown, it has been suggested to be a form of disseminated intravascular coagulation (DIC).

Objectives

The aim of our study was to analyze the coagulation parameters of patients with COVID‐19, determine whether coagulation factors consumption occurs and identify potential prognostic biomarkers of the disease.

Patients/Methods

Blood samples from hospitalized patients with COVID‐19 pneumonia were collected. We performed basic coagulation tests and quantification of coagulation factors and physiological inhibitor proteins. Laboratory data were compared with clinical data and outcomes.

Results

The study involved 206 patients (63.6% male). D‐dimer was particularly elevated (median 450 ng/mL; IQR 222.5‐957.3). Free protein S levels were below the normal range (median 56.6%; IQR: 43.6‐68.9), and factor VIII showed an increasing trend (median 173.4%; IQR: 144.1‐214.9). However, all coagulation factors were within normal limits. We found no correlation between abnormal coagulation parameters and thrombosis, except for higher D‐dimer (HR 1.99; 95% CI 1.3‐3.1; P = .002).

Conclusions

COVID‐19 is associated with coagulopathy that correlates with poor prognosis. However, we did not demonstrate a consumption of coagulation factors, as seen in DIC.

A current review of COVID-19 for the cardiovascular specialist

Although coronavirus disease 2019 (COVID-19) predominantly disrupts the respiratory system, there is accumulating experience that the disease, particularly in its more severe manifestations, also affects the cardiovascular system. Cardiovascular risk factors and chronic cardiovascular conditions are prevalent among patients affected by COVID-19 and associated with adverse outcomes. However, whether pre-existing cardiovascular disease is an independent determinant of higher mortality risk with COVID-19 remains uncertain. Acute cardiac injury, manifest by increased blood levels of cardiac troponin, electrocardiographic abnormalities, or myocardial dysfunction, occurs in up to ~60% of hospitalized patients with severe COVID-19. Potential contributors to acute cardiac injury in the setting of COVID-19 include (1) acute changes in myocardial demand and supply due to tachycardia, hypotension, and hypoxemia resulting in type 2 myocardial infarction; (2) acute coronary syndrome due to acute atherothrombosis in a virally induced thrombotic and inflammatory milieu; (3) microvascular dysfunction due to diffuse microthrombi or vascular injury; (4) stress-related cardiomyopathy (Takotsubo syndrome); (5) nonischemic myocardial injury due to a hyperinflammatory cytokine storm; or (6) direct viral cardiomyocyte toxicity and myocarditis. Diffuse thrombosis is emerging as an important contributor to adverse outcomes in patients with COVID-19. Practitioners should be vigilant for cardiovascular complications of COVID-19. Monitoring may include serial cardiac troponin and natriuretic peptides, along with fibrinogen, D-dimer, and inflammatory biomarkers. Management decisions should rely on the clinical assessment for the probability of ongoing myocardial ischemia, as well as alternative nonischemic causes of injury, integrating the level of suspicion for COVID-19.

Acute Pulmonary Embolism in COVID-19: A Report of Two Cases

Coronavirus disease 2019 (COVID-19), which is currently causing a global pandemic, is found to be associated with abnormal coagulation parameters and hyper-coagulable state with increased risk of venous thromboembolism (VTE). Here, we present two non-ICU cases of COVID-19, complicated with acute pulmonary embolism (PE). As of now, there are no proper guidelines established on anticoagulation in these patients. We discuss the pathophysiology and management strategy based on recently published studies on anticoagulation in COVID-19 patients. 

Pulmonary and systemic involvement in COVID-19 patients assessed with ultrasound-guided minimally invasive autopsy

Aims

Brazil ranks high in the number of coronavirus disease 19 (COVID‐19) cases and the COVID‐19 mortality rate. In this context, autopsies are important to confirm the disease, determine associated conditions, and study the pathophysiology of this novel disease. The aim of this study was to assess the systemic involvement of COVID‐19. In order to follow biosafety recommendations, we used ultrasound‐guided minimally invasive autopsy (MIA‐US), and we present the results of 10 initial autopsies.

Methods and results

We used MIA‐US for tissue sampling of the lungs, liver, heart, kidneys, spleen, brain, skin, skeletal muscle and testis for histology, and reverse transcription polymerase chain reaction to detect severe acute respiratory syndrome coronavirus 2 RNA. All patients showed exudative/proliferative diffuse alveolar damage. There were intense pleomorphic cytopathic effects on the respiratory epithelium, including airway and alveolar cells. Fibrinous thrombi in alveolar arterioles were present in eight patients, and all patients showed a high density of alveolar megakaryocytes. Small thrombi were less frequently observed in the glomeruli, spleen, heart, dermis, testis, and liver sinusoids. The main systemic findings were associated with comorbidities, age, and sepsis, in addition to possible tissue damage due to the viral infection, such as myositis, dermatitis, myocarditis, and orchitis.

Conclusions

MIA‐US is safe and effective for the study of severe COVID‐19. Our findings show that COVID‐19 is a systemic disease causing major events in the lungs and with involvement of various organs and tissues. Pulmonary changes result from severe epithelial injury and microthrombotic vascular phenomena. These findings indicate that both epithelial and vascular injury should be addressed in therapeutic approaches.

Acute aortic thrombosis in COVID-19

Acute aortic occlusion is an infrequent disease but with significant mortality. The new pandemic of the SARS-CoV-2 coronavirus disease (COVID-19) represents a great challenge for health systems. This contagious disease is generating high infection and mortality rates in several countries. It is speculated that the inflammatory process accompanying the infection is triggered by massive macrophage activation and is associated with the development of coagulopathy. We present three cases of COVID-19 patients, treated in our hospital during a period of 2 weeks, who presented with an acute thrombosis of the infrarenal abdominal aorta.

High D dimers and low global fibrinolysis coexist in COVID19 patients: what is going on in there?

BACKGROUD

COVID-19 coagulopathy linked to increased D-dimer levels has been associated with high mortality (Fei Z et al. in Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet (London, England) 395(10229):1054-62, 2020). While D-dimer is accepted as a disseminated intravascular coagulation marker, rotational thromboelastometry (ROTEM) also detects fibrinolysis (Wright FL et al. in Fibrinolysis shutdown correlates to thromboembolic events in severe COVID-19 infection. J Am Coll Surg (2020). Available from https://pubmed.ncbi.nlm.nih.gov/32422349/ [cited 14 Jun 2020]; Schmitt FCF et al. in Acute fibrinolysis shutdown occurs early in septic shock and is associated with increased morbidity and mortality: results of an observational pilot study. Ann Intensive Care 9(1):19, 2019). We describe the ROTEM profile in severely ill COVID-19 patients and compare it with the standard laboratory coagulation test.

METHODS

Adult patients diagnosed with COVID-19 admitted to the ICU were prospectively enrolled after Ethics Committee approval (HCB/2020/0371). All patients received venous thromboembolism prophylaxis; those on therapeutic anticoagulation were excluded. The standard laboratory coagulation test and ROTEM were performed simultaneously at 24-48 h after ICU admission. Sequential organ failure assessment (SOFA), disseminated intravascular coagulation (DIC) and sepsis-induced coagulopathy (SIC) scores were calculated at sample collection.

RESULTS

Nineteen patients were included with median SOFA-score of 4 (2-6), DIC-score of 1 (0-3) and SIC-score of 1.8 (0.9). Median fibrinogen, D-dimer levels and platelet count were 6.2 (4.8-7.6 g/L), 1000 (600-4200 ng/ml) and 236 (136-364 10⁹/L), respectively. Clot firmness was above the normal range in the EXTEM and FIBTEM tests while clot lysis was decreased. There was no significant correlation between ROTEM or D-dimer parameters and the SOFA score.

CONCLUSION

In COVID-19 patients, the ROTEM pattern was characterized by a hypercoagulable state with decreased fibrinolytic capacity despite a paradoxical increase in D-dimer levels. We suggest that, in COVID-19 patients, the lungs could be the main source of D-dimer, while a systemic hypofibrinolytic state coexists. This hypothesis should be confirmed by future studies.

Histopathological findings in a COVID-19 patient affected by ischemic gangrenous cholecystitis

BACKGROUND

Since its first documentation, a novel coronavirus (SARS-CoV-2) infection has emerged worldwide, with the consequent declaration of a pandemic disease (COVID-19). Severe forms of acute respiratory failure can develop. In addition, SARS-CoV-2 may affect organs other than the lung, such as the liver, with frequent onset of late cholestasis. We here report the histological findings of a COVID-19 patient, affected by a tardive complication of acute ischemic and gangrenous cholecystitis with a perforated and relaxed gallbladder needing urgent surgery.

CASE PRESENTATION

A 59-year-old Caucasian male, affected by acute respiratory failure secondary to SARS-CoV-2 infection was admitted to our intensive care unit (ICU). Due to the severity of the disease, invasive mechanical ventilation was instituted and SARS-CoV-2 treatment (azithromycin 250 mg once-daily and hydroxychloroquine 200 mg trice-daily) started. Enoxaparin 8000 IU twice-daily was also administered subcutaneously. At day 8 of ICU admission, the clinical condition improved and patient was extubated. At day 32, patient revealed abdominal pain without signs of peritonism at examination, with increased inflammatory and cholestasis indexes at blood tests. At a first abdominal CT scan, perihepatic effusion and a relaxed gallbladder with dense content were detected. The surgeon decided to wait and see the evolution of clinical conditions. The day after, conditions further worsened and a laparotomic cholecystectomy was performed. A relaxed and perforated ischemic gangrenous gallbladder, with a local tissue inflammation and perihepatic fluid, was intraoperatively met. The gallbladder and a sample of omentum, adherent to the gallbladder, were also sent for histological examination. Hematoxylin-eosin-stained slides display inflammatory infiltration and endoluminal obliteration of vessels, with wall breakthrough, hemorrhagic infarction, and nerve hypertrophy of the gallbladder. The mucosa of the gallbladder appears also atrophic. Omentum vessels also appear largely thrombosed. Immunohistochemistry demonstrates an endothelial overexpression of medium-size vessels (anti-CD31), while not in micro-vessels, with a remarkable activity of macrophages (anti-CD68) and T helper lymphocytes (anti-CD4) against gallbladder vessels. All these findings define a histological diagnosis of vasculitis of the gallbladder.

CONCLUSIONS

Ischemic gangrenous cholecystitis can be a tardive complication of COVID-19, and it is characterized by a dysregulated host inflammatory response and thrombosis of medium-size vessels.

Thrombosis and coagulopathy in COVID-19: An illustrated review

This illustrated review discusses the haemostatic changes seen in patients with severe coronavirus disease 2019 (COVID-19) infection and their possible causes. We discuss the crosstalk between inflammation and coagulation resulting in high levels of acute-phase proteins, very high levels of D-dimers, and absence of disseminated intravascular coagulation seen in patients with severe COVID-19. There appear to be high rates of venous thromboembolism and also, what has been poorly described before in acute lung injury, a high rate of pulmonary immunothrombosis (thrombosis secondary to inflammation).

Thoughts on the alveolar phase of COVID-19

COVID-19 can be divided into three clinical stages, and one can speculate that these stages correlate with where the infection resides. For the asymptomatic phase, the infection mostly resides in the nose, where it elicits a minimal innate immune response. For the mildly symptomatic phase, the infection is mostly in the pseudostratified epithelium of the larger airways and is accompanied by a more vigorous innate immune response. In the conducting airways, the epithelium can recover from the infection, because the keratin 5 basal cells are spared and they are the progenitor cells for the bronchial epithelium. There may be more severe disease in the bronchioles, where the club cells are likely infected. The devastating third phase is in the gas exchange units of the lung, where ACE2-expressing alveolar type II cells and perhaps type I cells are infected. The loss of type II cells results in respiratory insufficiency due to the loss of pulmonary surfactant, alveolar flooding, and possible loss of normal repair, since type II cells are the progenitors of type I cells. The loss of type I and type II cells will also block normal active resorption of alveolar fluid. Subsequent endothelial damage leads to transudation of plasma proteins, formation of hyaline membranes, and an inflammatory exudate, characteristic of ARDS. Repair might be normal, but if the type II cells are severely damaged alternative pathways for epithelial repair may be activated, which would result in some residual lung disease.

COVID-19 pneumonia with hemoptysis: Acute segmental pulmonary emboli associated with novel coronavirus infection

Recent retrospective studies from Wuhan, China suggest Novel Coronavirus Disease 2019 (COVID-19) may be associated with a hypercoagulable state and increased risk for venous thromboembolism. The overlap in the signs and symptoms of COVID-19 associated Acute Respiratory Distress Syndrome (ARDS) and COVID-19 with concurrent pulmonary embolism creates a diagnostic challenge for emergency medicine physicians in patients already at risk for renal impairment. However, identifying features atypical for COVID-19 alone may play a role in the judicious use of Computed Tomography Angiography among these patients. Hemoptysis is seen in roughly 13% of pulmonary embolism cases and infrequently reported among COVID-19 infections. Additionally, the presence of right heart strain on electrocardiography (EKG) is a well described clinical presentations of pulmonary embolism not reported commonly with COVID-19 infections.

Fibrinolytic abnormalities in acute respiratory distress syndrome (ARDS) and versatility of thrombolytic drugs to treat COVID-19

The global pandemic of coronavirus disease 2019 (COVID-19) is associated with the development of acute respiratory distress syndrome (ARDS), which requires ventilation in critically ill patients. The pathophysiology of ARDS results from acute inflammation within the alveolar space and prevention of normal gas exchange. The increase in proinflammatory cytokines within the lung leads to recruitment of leukocytes, further propagating the local inflammatory response. A consistent finding in ARDS is the deposition of fibrin in the air spaces and lung parenchyma. COVID-19 patients show elevated D-dimers and fibrinogen. Fibrin deposits are found in the lungs of patients due to the dysregulation of the coagulation and fibrinolytic systems. Tissue factor (TF) is exposed on damaged alveolar endothelial cells and on the surface of leukocytes promoting fibrin deposition, while significantly elevated levels of plasminogen activator inhibitor 1 (PAI-1) from lung epithelium and endothelial cells create a hypofibrinolytic state. Prophylaxis treatment of COVID-19 patients with low molecular weight heparin (LMWH) is important to limit coagulopathy. However, to degrade pre-existing fibrin in the lung it is essential to promote local fibrinolysis. In this review, we discuss the repurposing of fibrinolytic drugs, namely tissue-type plasminogen activator (tPA), to treat COVID-19 associated ARDS. tPA is an approved intravenous thrombolytic treatment, and the nebulizer form has been shown to be effective in plastic bronchitis and is currently in Phase II clinical trial. Nebulizer plasminogen activators may provide a targeted approach in COVID-19 patients to degrade fibrin and improving oxygenation in critically ill patients.

A Comprehensive Review of Manifestations of Novel Coronaviruses in the Context of Deadly COVID-19 Global Pandemic

Since December 2019, the global pandemic caused by the highly infectious novel coronavirus 2019-nCoV (COVID-19) has been rapidly spreading. As of April 2020, the outbreak has spread to over 210 countries, with over 2,400,000 confirmed cases and over 170,000 deaths.1 COVID-19 causes a severe pneumonia characterized by fever, cough and shortness of breath. Similar coronavirus outbreaks have occurred in the past causing severe pneumonia like COVID-19, most recently, severe acute respiratory syndrome coronavirus (SARS-CoV) and middle east respiratory syndrome coronavirus (MERS-CoV). However, over time, SARS-CoV and MERS-CoV were shown to cause extrapulmonary signs and symptoms including hepatitis, acute renal failure, encephalitis, myositis and gastroenteritis. Similarly, sporadic reports of COVID-19 related extrapulmonary manifestations emerge. Unfortunately, there is no comprehensive summary of the multiorgan manifestations of COVID-19, making it difficult for clinicians to quickly educate themselves about this highly contagious and deadly pathogen. What is more, is that SARS-CoV and MERS-CoV are the closest humanity has come to combating something similar to COVID-19, however, there exists no comparison between the manifestations of any of these novel coronaviruses. In this review, we summarize the current knowledge of the manifestations of the novel coronaviruses SARS-CoV, MERS-CoV and COVID-19, with a particular focus on the latter, and highlight their differences and similarities.

Endotheliopathy in COVID-19-associated coagulopathy: evidence from a single-centre, cross-sectional study

BACKGROUND

An important feature of severe acute respiratory syndrome coronavirus 2 pathogenesis is COVID-19-associated coagulopathy, characterised by increased thrombotic and microvascular complications. Previous studies have suggested a role for endothelial cell injury in COVID-19-associated coagulopathy. To determine whether endotheliopathy is involved in COVID-19-associated coagulopathy pathogenesis, we assessed markers of endothelial cell and platelet activation in critically and non-critically ill patients admitted to the hospital with COVID-19.

METHODS

In this single-centre cross-sectional study, hospitalised adult (≥18 years) patients with laboratory-confirmed COVID-19 were identified in the medical intensive care unit (ICU) or a specialised non-ICU COVID-19 floor in our hospital. Asymptomatic, non-hospitalised controls were recruited as a comparator group for biomarkers that did not have a reference range. We assessed markers of endothelial cell and platelet activation, including von Willebrand Factor (VWF) antigen, soluble thrombomodulin, soluble P-selectin, and soluble CD40 ligand, as well as coagulation factors, endogenous anticoagulants, and fibrinolytic enzymes. We compared the level of each marker in ICU patients, non-ICU patients, and controls, where applicable. We assessed correlations between these laboratory results with clinical outcomes, including hospital discharge and mortality. Kaplan-Meier analysis was used to further explore the association between biochemical markers and survival.

FINDINGS

68 patients with COVID-19 were included in the study from April 13 to April 24, 2020, including 48 ICU and 20 non-ICU patients, as well as 13 non-hospitalised, asymptomatic controls. Markers of endothelial cell and platelet activation were significantly elevated in ICU patients compared with non-ICU patients, including VWF antigen (mean 565% [SD 199] in ICU patients vs 278% [133] in non-ICU patients; p<0·0001) and soluble P-selectin (15·9 ng/mL [4·8] vs 11·2 ng/mL [3·1]; p=0·0014). VWF antigen concentrations were also elevated above the normal range in 16 (80%) of 20 non-ICU patients. We found mortality to be significantly correlated with VWF antigen (r = 0·38; p=0·0022) and soluble thrombomodulin (r = 0·38; p=0·0078) among all patients. In all patients, soluble thrombomodulin concentrations greater than 3·26 ng/mL were associated with lower rates of hospital discharge (22 [88%] of 25 patients with low concentrations vs 13 [52%] of 25 patients with high concentrations; p=0·0050) and lower likelihood of survival on Kaplan-Meier analysis (hazard ratio 5·9, 95% CI 1·9-18·4; p=0·0087).

INTERPRETATION

Our findings show that endotheliopathy is present in COVID-19 and is likely to be associated with critical illness and death. Early identification of endotheliopathy and strategies to mitigate its progression might improve outcomes in COVID-19.

FUNDING

This work was supported by a gift donation from Jack Levin to the Benign Hematology programme at Yale, and the National Institutes of Health.

Pulmonary Embolism in COVID-19 Pneumonia: Random Association or Causality?

Coronavirus disease 2019 (COVID-19) is an ongoing pandemic. COVID-19 leads to a plethora of clinical syndromes, most commonly affecting the pulmonary system but also the cardiovascular, hematologic, and gastrointestinal systems. There is emerging evidence of an association between COVID-19 and venous thromboembolism (VTE). In this report, we have discussed three cases with a COVID-19 infection, whose clinical course was complicated by the presence of pulmonary embolism (PE) without evident risk factors for VTE. All three patients presented with hypoxia and were found to have elevated D-dimer levels. Subsequently, the patients underwent computed tomography (CT) angiography of the chest, which confirmed the presence of pulmonary embolism. Anticoagulation was initiated per guidelines. There is a need to have a low threshold for suspecting pulmonary embolism in patients with COVID-19 infection who present with a sudden onset of severe hypoxia. There is a dire need to increase awareness among health care providers regarding this manifestation of the virus.

Antirheumatic drugs for COVID-19 treatment based on the phases of the disease: Current concept

COVID-19 disease is the most recent pandemic, since it has affected more than four and a half million people and caused more than 300,000 deaths. It is a very complex systemic disease in terms of pathogenesis, treatment, and prognosis. Pharmacological treatment may include antiviral and antimalarial drugs, antibiotics, monoclonal antibodies, corticosteroids as well as low-molecular-weight heparins to prevent the evolution of the disease from reaching the severe inflammatory phase that can lead to respiratory complications, multiple organ failure, disseminated intravascular coagulation (DIC), and finally death. Therefore, pending the development of the much sought-after vaccine, there needs to be a multidisciplinary approach to tackling this disease, and it is essential to use different medical treatments at the correct pathogenic moment. The aim of this article is to evaluate the rationale and reason behind the use of antirheumatic drugs, by expert point of view, in the various phases of the disease. Another important aspect in the management of the disease is to identify patients at high risk, both to change their lifestyle and to correct the state of their health through non-pharmacological measures for improving their immuno-balance. Our literature review reveals the important role and the therapeutic potential of antirheumatic agents in preventing the progression of the disease and aiding recovery from the disease. However, there is a lack of clinical evidence to support the use of these agents, indicating that further randomized controlled studies are required.

COVID-19: The Potential Treatment of Pulmonary Fibrosis Associated with SARS-CoV-2 Infection

In December 2019, a novel coronavirus, SARS-CoV-2, appeared, causing a wide range of symptoms, mainly respiratory infection. In March 2020, the World Health Organization (WHO) declared Coronavirus Disease 2019 (COVID-19) a pandemic, therefore the efforts of scientists around the world are focused on finding the right treatment and vaccine for the novel disease. COVID-19 has spread rapidly over several months, affecting patients across all age groups and geographic areas. The disease has a diverse course; patients may range from asymptomatic to those with respiratory failure, complicated by acute respiratory distress syndrome (ARDS). One possible complication of pulmonary involvement in COVID-19 is pulmonary fibrosis, which leads to chronic breathing difficulties, long-term disability and affects patients' quality of life. There are no specific mechanisms that lead to this phenomenon in COVID-19, but some information arises from previous severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS) epidemics. The aim of this narrative review is to present the possible causes and pathophysiology of pulmonary fibrosis associated with COVID-19 based on the mechanisms of the immune response, to suggest possible ways of prevention and treatment.

The unique characteristics of COVID-19 coagulopathy

Thrombotic complications and coagulopathy frequently occur in COVID-19. However, the characteristics of COVID-19-associated coagulopathy (CAC) are distinct from those seen with bacterial sepsis-induced coagulopathy (SIC) and disseminated intravascular coagulation (DIC), with CAC usually showing increased D-dimer and fibrinogen levels but initially minimal abnormalities in prothrombin time and platelet count. Venous thromboembolism and arterial thrombosis are more frequent in CAC compared to SIC/DIC. Clinical and laboratory features of CAC overlap somewhat with a hemophagocytic syndrome, antiphospholipid syndrome, and thrombotic microangiopathy. We summarize the key characteristics of representative coagulopathies, discussing similarities and differences so as to define the unique character of CAC.

The vascular endothelium: the cornerstone of organ dysfunction in severe SARS-CoV-2 infection

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.

Doxycycline as a potential partner of COVID-19 therapies

Coronavirus disease 2019 (COVID-19) is a major public health challenge, and the current antiviral arsenal for treatment is limited, with questionable efficacy. Major efforts are under way for discovery of new effective agents, but the validation of new potential treatments for COVID-19 may take a long time. Therefore, the repurposing of existing drugs for new indications is needed. In this article, we argue for the potential benefits of using doxycycline with either hydroxycholoroquine or other putative agents for COVID-19 treatment, as doxycycline has antiviral and anti-inflammatory activities by dampening the cytokine storm and to prevent lung damage.