COVID-19 update: Covid-19-associated coagulopathy

A systematic review on neutrophil extracellular traps and its prognostication role in COVID-19 patients

Neutrophil extracellular traps (NETs) are extracellular webs composed of neutrophil granular and nuclear elements. Because of the potentially dangerous amplification circuit between inflammation and tissue damage, NETs are becoming one of the investigated components in the current Coronavirus Disease 2019 (COVID-19) pandemic. The purpose of this systematic review is to summarize studies on the role of NETs in determining the prognosis of COVID-19 patients. The study used six databases: PubMed, Science Direct, EBSCOHost, Europe PMC, ProQuest, and Scopus. This literature search was implemented until October 31, 2021. The search terms were determined specifically for each databases, generally included the Neutrophil Extracellular Traps, COVID-19, and prognosis. The Newcastle Ottawa Scale (NOS) was then used to assess the risk of bias. Ten studies with a total of 810 participants were chosen based on the attainment of the prerequisite. Two were of high quality, seven were of moderate quality, and the rest were of low quality. The majority of studies compared COVID-19 to healthy control. Thrombosis was observed in three studies, while four studies recorded the need for mechanical ventilation. In COVID-19 patients, the early NETs concentration or the evolving NETs degradations can predict patient mortality. Based on their interactions with inflammatory and organ dysfunction markers, it is concluded that NETs play a significant role in navigating the severity of COVID-19 patients and thus impacting their prognosis.

Hormonal therapies and venous thrombosis: Considerations for prevention and management

Background

Venous thromboses are well-established complications of hormonal therapy. Thrombosis risk is seen with both hormonal contraceptive agents and with hormone replacement therapy for menopause and gender transition. Over the past several decades, large epidemiological studies have helped better define these risks.

Objectives

To review and discuss the differences in thrombosis risk of the many of hormonal preparations available as well as their interaction with patient-specific factors.

Methods

We conducted a narrative review of the available literature regarding venous thrombosis and hormonal therapies including for contraception, menopausal symptoms, and gender transition.

Results

Thrombosis risk with estrogen-containing compounds increases with increasing systemic dose of estrogen. While progesterone-only-containing products are not associated with thrombosis, when paired with estrogen in combined oral contraceptives, the formulation of progesterone does impact the risk. These components, along with patient-specific factors, may influence the choice of hormonal preparation. For patients who develop thrombosis on hormonal treatment, anticoagulation is protective against future thrombosis. Duration of anticoagulation is dependent on ongoing and future hormone therapy choice. Finally, the optimal management of hormone therapy for individuals diagnosed with prothrombotic illnesses such as COVID-19 remains unclear.

Conclusions

When contemplating hormonal contraception or hormone replacement therapy, clinicians must consider a variety of factors including hormone type, dose, route, personal and family history of thrombosis, and other prothrombotic risk factors to make informed, personalized decisions regarding the risk of venous thrombosis.

Epidemiology and Management of Cerebral Venous Thrombosis during the COVID-19 Pandemic

Cerebral venous thrombosis (CVT) is a rare type of stroke that may cause an intracranial hypertension syndrome as well as focal neurological deficits due to venous infarcts. MRI with venography is the method of choice for diagnosis, and treatment with anticoagulants should be promptly started. CVT incidence has increased in COVID-19-infected patients due to a hypercoagulability state and endothelial inflammation. CVT following COVID-19 vaccination could be related to vaccine-induced immune thrombotic thrombocytopenia (VITT), a rare but severe complication that should be promptly identified because of its high mortality rate. Platelet count, D-dimer and PF4 antibodies should be dosed. Treatment with non-heparin anticoagulants and immunoglobulin could improve recuperation. Development of headache associated with seizures, impaired consciousness or focal signs should raise immediate suspicion of CVT. In patients who received a COVID-19 adenovirus-vector vaccine presenting thromboembolic events, VITT should be suspected and rapidly treated. Nevertheless, vaccination benefits clearly outweigh risks and should be continued.

Clinical Significance of Antineutrophil Cytoplasmic Antibody Positivity in Patients Infected with SARS-CoV-2

Objectives: To investigate the rate of antineutrophil cytoplasmic antibody (ANCA) positivity and its clinical significance in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: This study included 178 patients infected with SARS-CoV-2 who were enrolled in a cohort at a single centre. Myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA levels in stored blood sera were measured using immunoassay kits. Mortality, mechanical ventilator care, and severe infection were assessed as three poor outcomes. The 2022 American College of Rheumatology and the European Alliance of Associations for Rheumatology (ACR/EULAR) classification criteria for the three subtypes of AAV were applied only to patients who had MPO-ANCA or PR3-ANCA among study subjects. Results: The detection rate of ANCA positivity was 18.5%. MPO-ANCA and PR3-ANCA were found in 22 (12.4%) and 14 (7.9%) patients, respectively. However, neither MPO-ANCA nor PR3-ANCA affected the three poor outcomes. According to the new criteria, 12 (6.7%) and 21 (11.8%) patients were classified as having granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), respectively. Conclusions: SARS-CoV-2 infection may increase the rate of ANCA positivity. Although it might not affect poor outcomes, it might contribute to the classification of GPA and MPA despite uncertain clinical significance.

Role of Acute Thrombosis in Coronavirus Disease 2019

Patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are prone to venous, cerebrovascular, and coronary thrombi, particularly those with severe coronavirus disease 2019 (COVID-19). The pathogenesis is multifactorial and likely involves proinflammatory cascades, development of coagulopathy, and neutrophil extracellular traps, although further investigations are needed. Elevated levels of D-dimers are common in patients with COVID-19 and cannot be used in isolation to predict venous thromboembolism in people with SARS-CoV-2. If given early in hospital admission, therapeutic-dose heparin improves clinical outcomes in patients with moderate COVID-19. To date, antithrombotics have not improved outcomes in patients with severe COVID-19.

COVID-19 and the injured patient: A multicenter review

Introduction

Coronavirus disease 2019 (COVID-19) has been shown to affect outcomes among surgical patients. We hypothesized that COVID-19 would be linked to higher mortality and longer length of stay of trauma patients regardless of the injury severity score (ISS).

Methods

We performed a retrospective analysis of trauma registries from two level 1 trauma centers (suburban and urban) from March 1, 2019, to June 30, 2019, and March 1, 2020, to June 30, 2020, comparing baseline characteristics and cumulative adverse events. Data collected included ISS, demographics, and comorbidities. The primary outcome was time from hospitalization to in-hospital death. Outcomes during the height of the first New York COVID-19 wave were also compared with the same time frame in the prior year. Kaplan–Meier method with log-rank test and Cox proportional hazard models were used to compare outcomes.

Results

There were 1180 trauma patients admitted during the study period from March 2020 to June 2020. Of these, 596 were never tested for COVID-19 and were excluded from the analysis. A total of 148 COVID+ patients and 436 COVID− patients composed the 2020 cohort for analysis. Compared with the 2019 cohort, the 2020 cohort was older with more associated comorbidities, more adverse events, but lower ISS. Higher rates of historical hypertension, diabetes, neurologic events, and coagulopathy were found among COVID+ patients compared with COVID− patients. D-dimer and ferritin were unreliable indicators of COVID-19 severity; however, C-reactive protein levels were higher in COVID+ relative to COVID− patients. Patients who were COVID+ had a lower median ISS compared with COVID− patients, and COVID+ patients had higher rates of mortality and longer length of stay.

Conclusions

COVID+ trauma patients admitted to our two level 1 trauma centers had increased morbidity and mortality compared with admitted COVID− trauma patients despite age and lower ISS. C-reactive protein may play a role in monitoring COVID-19 activity in trauma patients. A better understanding of the physiological impact of COVID-19 on injured patients warrants further investigation.

MECHANICAL VENTILATION NEED AND GLYCEMIC STATUS IN PATIENTS WITH COVID -19: A FOLLOW-UP STUDY

Context

Diabetes mellitus is a well known risk factor for COVID-19 patients. However, There is limited data to investigate the association between prediabetes and COVID-19.

Objective

We aimed to evaluate the effect of prediabetes and mechanical ventilation on the course of COVID-19 and determine whether patients who recover from COVID-19 infection show changes in cardiac function and laboratory findings during follow-up.

Patients and Methods

This study included 87 adult patients who were diagnosed with COVID-19 according to the WHO definition and were admitted for inpatient treatment between April 2021 and August 2021. They were classified into 3 groups, normoglycemia (n=40), prediabetes (n=25), and diabetes (n=22), and then divided into groups according to need for mechanical ventilation. Statistical analyses were performed to compare laboratory, echocardiographic findings and COVID-19 outcomes among the groups.

Results

The need of mechanical ventilation was significantly higher in both diabetes and prediabetes groups than the normoglycemic group. Patients with diabetes and prediabetes had significantly higher LV E/Em (p=0.003, p=0.045) and RV MPI (p=0.032, p=0.021) and significantly shorter PAT (p=0.001, p=0.036) and significantly longer RV IVRT (p=0.021, p=0.017), respectively, compared to the normoglycemia group. Patients who required mechanical ventilation had significantly higher CRP (p=0.043), troponin (p<0.001), ferritin (p<0.001), HBA1C (P<0.001), glucose (p=0.019), monocytes (p<0.001), and monocytes-HDL ratio (MHR) (p<0.001) and significantly lower levels of HDL-C (p<0.001). Glucose, HDL-C, troponin, MPV, NLR, PLR level and RV and E/Em were found independently associated with the RVMPI.

Conclusion

Prediabetes was associated with more impaired LV and RV diastolic functions compared to normoglycemic patients, comparable to those seen in diabetes. Our observations suggest that prediabetes should be considered as diabetes in the risk stratification of patients with COVID-19.

Hypercoagulability in COVID-19: from an unknown beginning to future therapies

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global public health concern and is characterized by an exaggerated inflammatory response that can lead to a large variety of clinical manifestations such as respiratory distress, sepsis, coagulopathy, and death. While it was initially considered primarily a respiratory illness, different data suggests that COVID-19 can lead to a pro-inflammatory milieu and a hypercoagulable state. Several mechanisms attempt to explain the pro-coagulant state seen in COVID-19 patients, including increased fibrinogen concentration, different receptor binding, exhausted fibrinolysis, cytokine storm, and endothelial dysfunction. Some hematological parameters, such as elevated D-dimers and other fibrinolytic products, indicate that the essence of coagulopathy is massive fibrin formation. Moreover, elevated D-dimer levels have emerged as an independent risk factor for a worse outcome, including death, indicating a potential risk for deep vein thrombosis and pulmonary thromboembolism. Prophylactic anticoagulation is recommended in all in-patients with COVID-19 to reduce the incidence of thrombosis. Those with elevated D-dimer values or with a higher risk of developing thromboembolic events should be treated with higher doses of anticoagulant. Anticoagulation may not be enough in some circumstances, highlighting the need for alternative therapies. An understanding of the complex cross-talk between inflammation and coagulopathy is necessary for developing direct appropriate interventional strategies.

Correlación entre el aumento del dímero D en sangre con el espacio muerto en pacientes con COVID-19 y síndrome de dificultad respiratoria aguda

Introducción

Desde diciembre de 2019, un número de casos de neumonía por síndrome respiratorio agudo severo (SARS) CoV2/COVID-19 en Wuhan, China, se identificaron como causa de insuficiencia respiratoria aguda, y se propagaron por el mundo a gran velocidad. Debido al gran número de casos y a la necesidad de entender más esta condición, surge la necesidad de identificar herramientas que gradúen la intensidad y el pronóstico vital de los pacientes. El objetivo de este estudio es determinar la relación entre el espacio muerto medido por capnografía volumétrica o por ventilatory ratio y el aumento de los niveles de dímero D en los pacientes con diagnóstico de neumonía por COVID-19 y que cumplan los criterios de Berlín para síndrome de dificultad respiratoria aguda (SDRA).

Materiales y métodos

Se realizó un estudio observacional de una cohorte prospectiva, monocéntrico, sobre el uso de dímero D y la correlación con el espacio muerto. Se incluyeron adultos mayores de 18 años con diagnóstico de neumonía por COVID-19 y SDRA hospitalizados en las unidades de cuidados intensivos del Hospital Santa Clara en Bogotá, Colombia, desde agosto de 2020 hasta julio de 2021.

Resultados

El estudio incluyó 67 pacientes, con diagnóstico de SARS-CoV-2 confirmado en todos ellos, no se encontró asociación entre dímero D y espacio muerto en el día 1 y 3 de la hospitalización en la UCI.

Conclusión

El dímero D no se correlaciona con el aumento del espacio muerto en nuestro estudio y tampoco se asoció con los desenlaces clínicos relevantes en los pacientes con SDRA.

Bleeding and thrombosis outcomes in hospitalised COVID-19 patients on low-molecular-weight heparin and antiplatelet therapy

Background. An increased incidence of thromboembolic events in hospitalised COVID‐19 patients has been demonstrated despite the use of low‐molecular‐weight heparin (LMWH). Antiplatelet therapy prior to admission and early in the disease course has been hypothesised to be protective against thrombosis.Objectives. To describe the bleeding and thrombosis outcomes in hospitalised patients with confirmed COVID‐19 receiving LMWH, with and without concomitant antiplatelet therapy. Secondary objectives were to explore predictors of bleeding and thrombosis outcomes, and dosing practices of antiplatelet therapy and LMWH. Methods. We conducted a descriptive, cross‐sectional study of bleeding and thrombosis outcomes at Tygerberg Academic Hospital, Cape Town, South Africa, during the first COVID‐19 wave, in 808 hospitalised patients with confirmed COVID‐19 receiving LMWH with and without concomitant antiplatelet therapy. Multivariate logistic regression analysis was performed if predictors were deemed statistically and clinically significant. Results. Patients receiving both LMWH and antiplatelet therapy had similar bleeding outcomes compared with patients only receiving LMWH (odds ratio (OR) 1.5; 95% confidence interval (CI) 0.6 ‐ 4.0). Patients receiving both LMWH and antiplatelet therapy had increased odds of developing thrombosis compared with patients only receiving LMWH (OR 4.8; 95% CI 2.1 ‐ 10.7).Conclusion. The bleeding risk in COVID‐19 patients receiving both LMWH and antiplatelet therapy was not significantly increased. A potentially higher risk of thrombosis in patients receiving LMWH and antiplatelet therapy was observed. However, this could reflect confounding by indication. Randomised studies are required to further evaluate the use of antiplatelet therapy to treat hospitalised patients with COVID‐19.

Epidemiology, Clinico-Pathological Characteristics, and Comorbidities of SARS-CoV-2-Infected Pakistani Patients

SARS-CoV-2 is a causative agent for COVID-19 disease, initially reported from Wuhan, China. The infected patients experienced mild to severe symptoms, resulting in several fatalities due to a weak understanding of its pathogenesis, which is the same even to date. This cross-sectional study has been designed on 452 symptomatic mild-to-moderate and severe/critical patients to understand the epidemiology and clinical characteristics of COVID-19 patients with their comorbidities and response to treatment. The mean age of the studied patients was 58 ± 14.42 years, and the overall male to female ratio was 61.7 to 38.2%, respectively. In total, 27.3% of the patients had a history of exposure, and 11.9% had a travel history, while for 60% of patients, the source of infection was unknown. The most prevalent signs and symptoms in ICU patients were dry cough, myalgia, shortness of breath, gastrointestinal discomfort, and abnormal chest X-ray (p < 0.001), along with a high percentage of hypertension (p = 0.007) and chronic obstructive pulmonary disease (p = 0.029) as leading comorbidities. The complete blood count indicators were significantly disturbed in severe patients, while the coagulation profile and D-dimer values were significantly higher in mild-to-moderate (non-ICU) patients (p < 0.001). The serum creatinine (1.22 μmol L^-1; p = 0.016) and lactate dehydrogenase (619 μmol L^-1; p < 0.001) indicators were significantly high in non-ICU patients, while raised values of total bilirubin (0.91 μmol L^-1; p = 0.054), C-reactive protein (84.68 mg L^-1; p = 0.001), and ferritin (996.81 mg L^-1; p < 0.001) were found in ICU patients. The drug dexamethasone was the leading prescribed and administrated medicine to COVID-19 patients, followed by remdesivir, meropenem, heparin, and tocilizumab, respectively. A characteristic pattern of ground glass opacities, consolidation, and interlobular septal thickening was prominent in severely infected patients. These findings could be used for future research, control, and prevention of SARS-CoV-2-infected patients.

Retinal vascular occlusion in patients with the Covid-19 virus

Background

The coronavirus disease (COVID-19) can cause acute respiratory distress syndrome with dyspnea, anosmia, fever, and cough. Few studies describing ocular findings have been reported. The current case series, reports the clinical findings and natural history of patients with retinal vascular occlusion after COVID-19 infection.

Case presentations

Patients from multiple Brazilian hospitals who had clinical and laboratory diagnoses of COVID-19 with retinal vein or arterial occlusion were analyzed retrospectively. The baseline demographics, clinical presentations of COVID-19, comorbidities, risk factors for thromboembolic events, and use of anticoagulant drugs were reviewed. The relevant clinical findings associated with the retinal vascular occlusive event, management, and outcomes were reported. Fourteen cases of retinal vascular occlusion within 3 months of the laboratory confirmed COVID-19 infection were identified. Three of which required hospitalization for COVID-19 management. Eight cases had central retinal vein occlusion, three branch retinal vein occlusion, one hemispheric retinal vein occlusion, and two central arterial occlusion. The mean patient age at presentation was 48 years; the visual acuity ranged from light perception to 20/20. Nine patients received intravitreal injections of anti-angiogenic drugs and one received ketorolac tromethamine drops for the management of secondary macular edema; four were untreated.

Conclusions

COVID-19 patients may rarely have ocular manifestations of the disease. It was presented a case series of vascular occlusion events that may be related to COVID-19 infection, since these thrombotic events are actively involved in the disease pathophysiology. These cases emphasize the need for further investigation of ocular complications associated with this disease.

Assessment of Jordanian physicians’ knowledge about venous thromboembolism risk and management among COVID-19 patients

Objectives

The aim of this study was to assess Jordanian physicians’ awareness about venous thromboembolism (VTE) risk among COVID-19 patients and its treatment protocol.

Methods

This was a cross-sectional-based survey that was conducted in Jordan in 2020. During the study period, a convenience sample of physicians working in various Jordanian hospitals were invited to participate in this study. Physicians’ knowledge was evaluated and physicians gained one point for each correct answer. Then, a knowledge score out of 23 was calculated for each.

Key findings

In this study, 102 physicians were recruited. Results from this study showed that most of the physicians realize that all COVID-19 patients need VTE risk assessment (n = 69, 67.6%). Regarding VTE prophylaxis, the majority of physicians (n = 91, 89.2%) agreed that low molecular weight heparin (LMWH) is the best prophylactic option for mild-moderate COVID-19 patients with high VTE risk. Regarding severe/critically ill COVID-19 patients, 75.5% of physicians (n = 77) recognized that LMWH is the correct prophylactic option in this case, while 80.4% of them (n = 82) knew that mechanical prevention is the preferred prophylactic option for severe/critically ill COVID-19 patients with high bleeding risk. Moreover, 77.5% of physicians (n = 79) knew that LMWH is the treatment of choice for COVID-19 patients diagnosed with VTE. Finally, linear regression analysis showed that consultants had an overall higher knowledge score about VTE prevention and treatment in COVID-19 patients compared with residents (P = 0.009).

Conclusion

All physicians knew about VTE risk factors for COVID-19 patients. However, consultants showed better awareness of VTE prophylaxis and treatment compared with residents. We recommend educational workshops be conducted to enhance physicians’ knowledge and awareness about VTE thromboprophylaxis and management in COVID-19 patients.

Engineering viral genomics and nano-liposomes in microfluidic platforms for patient-specific analysis of SARS-CoV-2 variants

New variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are continuing to spread globally, contributing to the persistence of the COVID-19 pandemic. Increasing resources have been focused on developing vaccines and therapeutics that target the Spike glycoprotein of SARS-CoV-2. Recent advances in microfluidics have the potential to recapitulate viral infection in the organ-specific platforms, known as organ-on-a-chip (OoC), in which binding of SARS-CoV-2 Spike protein to the angiotensin-converting enzyme 2 (ACE2) of the host cells occurs. As the COVID-19 pandemic lingers, there remains an unmet need to screen emerging mutations, to predict viral transmissibility and pathogenicity, and to assess the strength of neutralizing antibodies following vaccination or reinfection. Conventional detection of SARS-CoV-2 variants relies on two-dimensional (2-D) cell culture methods, whereas simulating the micro-environment requires three-dimensional (3-D) systems. To this end, analyzing SARS-CoV-2-mediated pathogenicity via microfluidic platforms minimizes the experimental cost, duration, and optimization needed for animal studies, and obviates the ethical concerns associated with the use of primates. In this context, this review highlights the state-of-the-art strategy to engineer the nano-liposomes that can be conjugated with SARS-CoV-2 Spike mutations or genomic sequences in the microfluidic platforms; thereby, allowing for screening the rising SARS-CoV-2 variants and predicting COVID-19-associated coagulation. Furthermore, introducing viral genomics to the patient-specific blood accelerates the discovery of therapeutic targets in the face of evolving viral variants, including B1.1.7 (Alpha), B.1.351 (Beta), B.1.617.2 (Delta), c.37 (Lambda), and B.1.1.529 (Omicron). Thus, engineering nano-liposomes to encapsulate SARS-CoV-2 viral genomic sequences enables rapid detection of SARS-CoV-2 variants in the long COVID-19 era.

The Role of Exposomes in the Pathophysiology of Autoimmune Diseases II: Pathogens

In our continuing examination of the role of exposomes in autoimmune disease, we use this review to focus on pathogens. Infections are major contributors to the pathophysiology of autoimmune diseases through various mechanisms, foremost being molecular mimicry, when the structural similarity between the pathogen and a human tissue antigen leads to autoimmune reactivity and even autoimmune disease. The three best examples of this are oral pathogens, SARS-CoV-2, and the herpesviruses. Oral pathogens reach the gut, disturb the microbiota, increase gut permeability, cause local inflammation, and generate autoantigens, leading to systemic inflammation, multiple autoimmune reactivities, and systemic autoimmunity. The COVID-19 pandemic put the spotlight on SARS-CoV-2, which has been called “the autoimmune virus.” We explore in detail the evidence supporting this. We also describe how viruses, in particular herpesviruses, have a role in the induction of many different autoimmune diseases, detailing the various mechanisms involved. Lastly, we discuss the microbiome and the beneficial microbiota that populate it. We look at the role of the gut microbiome in autoimmune disorders, because of its role in regulating the immune system. Dysbiosis of the microbiota in the gut microbiome can lead to multiple autoimmune disorders. We conclude that understanding the precise roles and relationships shared by all these factors that comprise the exposome and identifying early events and root causes of these disorders can help us to develop more targeted therapeutic protocols for the management of this worldwide epidemic of autoimmunity.

Stroke in the COVID-19 pandemic era

Purpose

The aim of this article is to outline the impact of COVID-19 on the frequency of occurrence, course of stroke treatment, and to highlight the cause-effect relationship between SARS-CoV-2 infection and stroke on the basis of a literature overview.

Views

Since the end of 2019, the whole world has been struggling with the effects of the pandemic caused by the coronavirus SARS-CoV-2. The virus induces a wide spectrum of symptoms, ranging from mild or serious ones, which may lead to a severe multiorgan failure. Acute ischaemic stroke (AIS) might be associated with COVID-19 as a potentially fatal complication, while hemorrhagic stroke is less frequent. In most cases, stroke is caused by large artery occlusion. One of its reasons is hypercoagulation with a complex mechanism, which has not been fully explained. Research has shown that during COVID-19 pandemic, the number of patients admitted to hospitals due to AIS decreased. During the first pandemic wave there was no change regarding the proportion of patients with cerebral vessel obstruction who received endovascular treatment.

Conclusions

In the COVID-19 pandemic era, rapid intravenous administration of tissue plasminogen activator remains the main treatment for acute ischaemic stroke. Patients often fail to report to hospital for the fear of SARS-CoV-2 infection. It is of the utmost importance to raise society's awareness of the necessity to report to hospital when experiencing serious symptoms, including stroke.

Impact of the withdrawal of renin-angiotensin-aldosterone inhibitors on mortality in COVID-19 patients

Background

Methods

Results

Conclusion

Venous and arterial thrombosis in COVID-19: An updated narrative review

Hospitalized patients with coronavirus disease 2019 (COVID-19), particularly those admitted to the intensive care unit (ICU) are at high risk of morbidity and mortality. Several observational studies have described hemostatic derangements and thrombotic complications in patients with COVID-19. The aim of this review article is to summarize the current evidence on pathologic findings, pathophysiology, coagulation and hemostatic abnormalities, D-dimer's role in prognostication epidemiology and risk factors of thrombotic complications, and the role of prophylactic and therapeutic anticoagulation in patients with COVID-19. While existing evidence is limited in quality, COVID-19 appears to increase micro-and macro-vascular thrombosis rates in hospitalized and critically ill patients, which may contribute to the burden of disease. D-dimer can be used for risk stratification of hospitalized patients, but its role to guide anticoagulation therapy remains unclear. Evidence of higher quality is needed to address the role of therapeutic anticoagulation or high-intensity venous thromboembolism prophylaxis in COVID-19 patients. TAKE-HOME POINTS.

Critical role of nitric oxide in impeding COVID-19 transmission and prevention: a promising possibility

COVID-19 is a serious respiratory infection caused by a beta-coronavirus that is closely linked to SARS. Hypoxemia is a symptom of infection, which is accompanied by acute respiratory distress syndrome (ARDS). Augmenting supplementary oxygen may not always improve oxygen saturation; reversing hypoxemia in COVID-19 necessitates sophisticated means to promote oxygen transfer from alveoli to blood. Inhaled nitric oxide (iNO) has been shown to inhibit the multiplication of the respiratory coronavirus, a property that distinguishes it from other vasodilators. These findings imply that NO may have a crucial role in the therapy of COVID-19, indicating research into optimal methods to restore pulmonary physiology. According to clinical and experimental data, NO is a selective vasodilator proven to restore oxygenation by helping to normalize shunts and ventilation/perfusion mismatches. This study examines the role of NO in COVID-19 in terms of its specific physiological and biochemical properties, as well as the possibility of using inhaled NO as a standard therapy. We have also discussed how NO could be used to prevent and cure COVID-19, in addition to the limitations of NO.

Possible Role of Matrix Metalloproteinases and TGF-β in COVID-19 Severity and Sequelae

The costs of coronavirus disease 2019 (COVID-19) are devastating. With millions of deaths worldwide, specific serological biomarkers, antiviral agents, and novel therapies are urgently required to reduce the disease burden. For these purposes, a profound understanding of the pathobiology of COVID-19 is mandatory. Notably, the study of immunity against other respiratory infections has generated reference knowledge to comprehend the paradox of the COVID-19 pathogenesis. Past studies point to a complex interplay between cytokines and other factors mediating wound healing and extracellular matrix (ECM) remodeling that results in exacerbated inflammation, tissue injury, severe manifestations, and a sequela of respiratory infections. This review provides an overview of the immunological process elicited after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Also, we analyzed available data about the participation of matrix metalloproteinases (MMPs) and transforming growth factor-beta (TGF-β) in immune responses of the lungs. Furthermore, we discuss their possible implications in severe COVID-19 and sequela, including pulmonary fibrosis, and remark on the potential of these molecules as biomarkers for diagnosis, prognosis, and treatment of convalescent COVID-19 patients. Our review provides a theoretical framework for future research aimed to discover molecular hallmarks that, combined with clinical features, could serve as therapeutic targets and reliable biomarkers of the different clinical forms of COVID-19, including convalescence.

Exploring Endothelial Colony-Forming Cells to Better Understand the Pathophysiology of Disease: An Updated Review

Endothelial cell (EC) dysfunction has been implicated in a variety of pathological conditions. The collection of ECs from patients is typically conducted postmortem or through invasive procedures, such as surgery and interventional procedures, hampering efforts to clarify the role of ECs in disease onset and progression. In contrast, endothelial colony-forming cells (ECFCs), also termed late endothelial progenitor cells, late outgrowth endothelial cells, blood outgrowth endothelial cells, or endothelial outgrowth cells, are obtained in a minimally invasive manner, namely, by the culture of human peripheral blood mononuclear cells in endothelial growth medium. ECFCs resemble mature ECs phenotypically, genetically, and functionally, making them excellent surrogates for ECs. Numerous studies have been performed that examined ECFC function in conditions such as coronary artery disease, diabetes mellitus, hereditary hemorrhagic telangiectasia, congenital bicuspid aortic valve disease, pulmonary arterial hypertension, venous thromboembolic disease, and von Willebrand disease. Here, we provide an updated review of studies using ECFCs that were performed to better understand the pathophysiology of disease. We also discuss the potential of ECFCs as disease biomarkers and the standardized methods to culture, quantify, and evaluate ECFCs and suggest the future direction of research in this field.

Scrub Typhus and COVID-19 Coinfection Unmasking Antiphospholipid Antibody Syndrome

Scrub typhus is an acute febrile disease caused by Orientia tsutsugamushi with a clinical course varying from mild to fatal. Vascular thrombosis is rare in scrub typhus. There is an increased risk of thrombotic events in Coronavirus disease 19 (COVID-19). We report a young diabetic female who presented with pulmonary embolism, followed by deep venous thrombosis (DVT) and was found to have coinfection with scrub typhus and COVID-19 with underlying antiphospholipid antibody syndrome.

Acute Pulmonary Artery Thrombosis despite Anticoagulation in Patients with COVID-19 Pneumonia: A Single-Center Retrospective Cohort Study

(1) Background: We aimed to describe the clinical and imaging characteristics of patients diagnosed with pulmonary artery thrombosis (PAT) despite receiving anticoagulation with low-molecular-weight heparin (LMWH). (2) Methods: We retrospectively studied all hospitalized COVID-19 adult patients diagnosed with PAT between March 2020 and December 2021, who received LMWH for ≥72 h until the diagnosis of PAT. Acute PAT was confirmed by a CT pulmonary angiogram. (3) Results: We included 30 severe and critical COVID-19 patients. Median age was 62 (54–74) years, with 83.3% males, and comorbidities seen in 73.3%. PAT was diagnosed despite prophylactic (23.3%), intermediate (46.6%) or therapeutic (30%) doses of LMWH for a median time of 8 (4.7–12) days. According to their Wells score, 80% of patients had a low probability of pulmonary embolism diagnosis. PAT was localized in the lower lobes of the lungs in 76.6% of cases with 33.3% having bilateral involvement, with the distal, peripheral arteries being the most affected. At the PAT diagnosis we found a worsening of respiratory function, with seven patients progressing to mechanical ventilation (p = 0.006). The in-hospital mortality was 30%. (4) Conclusions: PAT should be considered in patients with severe and critical COVID-19, mainly in elderly male patients with comorbidities, irrespective of Wells score and LMWH anticoagulation.

Influence of sex on development of thrombosis in patients with COVID-19: From the CLOT-COVID study

Introduction

There has been limited data on the influence of sex on development of thrombosis in patients with coronavirus disease 2019 (COVID-19).

Materials and methods

The CLOT-COVID Study was a retrospective, multicenter cohort study enrolling 2894 consecutive hospitalized patients with COVID-19 among 16 centers in Japan from April 2021 to September 2021. We divided the entire cohort into the men (N = 1885) and women (N = 1009) groups.

Results

There were no significant differences in D-dimer levels at admission between men and women. Men had more severe status of the COVID-19 at admission compared with women (Mild: 57% versus 66%, Moderate: 34% versus 29%, and Severe: 9.1% versus 5.7%, P < 0.001). Men more often received pharmacological thromboprophylaxis than women (47% versus 35%, P < 0.001). During the hospitalization, men more often developed thrombosis than women (2.5% [95%CI, 1.9–3.3%] versus 0.8% [95%CI, 0.4–1.6%], P = 0.001). Men had numerically higher incidences of thrombosis than women in all subgroups of the worst severity of COVID-19 during the hospitalization (Mild: 0.3% versus 0.0%, Moderate: 1.6% versus 1.0%, and Severe: 11.1% versus 4.3%). Even after adjusting confounders in the multivariable logistic regression model, the excess risk of men relative to women remained significant for thrombosis (adjusted OR, 2.51; 95%CI, 1.16–5.43, P = 0.02).

Conclusions

In the current large observational study of patients with COVID-19, men had more severe status of the COVID-19 than women, and the risk of development of thrombosis was higher in men compared with women, which could be helpful in determining the patient-specific optimal management strategies for COVID-19.

Platelet activation by SARS-CoV-2 implicates the release of active tissue factor by infected cells

Platelets are hyperactivated in coronavirus disease 2019 (COVID-19). However, the mechanisms promoting platelet activation by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are not well understood. This may be due to inherent challenges in discriminating the contribution of viral vs host components produced by infected cells. This is particularly true for enveloped viruses and extracellular vesicles (EVs), as they are concomitantly released during infection and share biophysical properties. To study this, we evaluated whether SARS-CoV-2 itself or components derived from SARS-CoV-2-infected human lung epithelial cells could activate isolated platelets from healthy donors. Activation was measured by the surface expression of P-selectin and the activated conformation of integrin αIIbβ3, degranulation, aggregation under flow conditions, and the release of EVs. We find that neither SARS-CoV-2 nor purified spike activates platelets. In contrast, tissue factor (TF) produced by infected cells was highly potent at activating platelets. This required trace amounts of plasma containing the coagulation factors FX, FII, and FVII. Robust platelet activation involved thrombin and the activation of protease-activated receptor (PAR)-1 and -4 expressed by platelets. Virions and EVs were identified by electron microscopy. Through size-exclusion chromatography, TF activity was found to be associated with a virus or EVs, which were indistinguishable. Increased TF messenger RNA (mRNA) expression and activity were also found in lungs in a murine model of COVID-19 and plasma of severe COVID-19 patients, respectively. In summary, TF activity from SARS-CoV-2–infected cells activates thrombin, which signals to PARs on platelets. Blockade of molecules in this pathway may interfere with platelet activation and the coagulation characteristic of COVID-19.

A Pediatric COVID-19 Study: Retinal Nerve Fiber Layer, Ganglion Cell Layer, and Alterations in Choroidal Thickness in Swept-Source OCT Measurements

Purpose To investigate early covid measurements of central macular thickness (CMT), retinal nerve fiber layer (RNFL), ganglion cell layer (GCL) thickness, and choroidal thickness (ChT) in children recovered from coronavirus disease 2019 (COVID-19).

Methods This cross-sectional study was carried out 4 weeks after completed COVID-19 treatment. The diagnosis of the Alpha variant COVID-19 was made by the polymerase chain reaction test after prediagnosis with clinical, laboratory, and radiological findings. A total of 46 children were included in the study. Pediatric patients who received COVID-19 treatment comprised the COVID-19 group (24 children), and healthy children were enrolled in the control group (22 children). Only the right eyes of the participants were enrolled in the study. All pediatric patients in the COVID-19 group required hospitalization without the need for intubation. Swept-source optical coherence tomography (SS-OCT) was used to measure CMT, RNFL, and GCL thickness, and ChT measurements.

Results The COVID-19 and control groups had similar mean values of visual acuity, intraocular pressure, spherical equivalent, axial length, and CMT (p > 0.05 for all). RNFL thickening, GCL, and choroidal thinning were observed in all SS-OCT measurements of COVID-19 children. However, RNFL thickening was significant only in the global and nasal peripapillary quadrants. GCL thinning was significant in the nasal/inferior sector (p < 0.002 for all). Some significant correlations were observed between the mean levels of inflammatory markers and OCT measurements (p < 0.002).

Conclusion This study may be among the first reports of SS-OCT examination of COVID-19 children. OCT measurements showed changes in retinal and ChT in the COVID-19 children as in adult patients.

Virtual Screening for the Discovery of Microbiome β-Glucuronidase Inhibitors to Alleviate Cancer Drug Toxicity

Despite the potency of most first-line anti-cancer drugs, nonadherence to these drug regimens remains high and is attributable to the prevalence of "off-target" drug effects that result in serious adverse events (SAEs) like hair loss, nausea, vomiting, and diarrhea. Some anti-cancer drugs are converted by liver uridine 5'-diphospho-glucuronosyltransferases through homeostatic host metabolism to form drug-glucuronide conjugates. These sugar-conjugated metabolites are generally inactive and can be safely excreted via the biliary system into the gastrointestinal tract. However, β-glucuronidase (βGUS) enzymes expressed by commensal gut bacteria can remove the glucuronic acid moiety, producing the reactivated drug and triggering dose-limiting side effects. Small-molecule βGUS inhibitors may reduce this drug-induced gut toxicity, allowing patients to complete their full course of treatment. Herein, we report the discovery of novel chemical series of βGUS inhibitors by structure-based virtual high-throughput screening (vHTS). We developed homology models for βGUS and applied them to large-scale vHTS against nearly 400,000 compounds within the chemical libraries of the National Center for Advancing Translational Sciences at the National Institutes of Health. From the vHTS results, we cherry-picked 291 compounds via a multifactor prioritization procedure, providing 69 diverse compounds that exhibited positive inhibitory activity in a follow-up βGUS biochemical assay in vitro. Our findings correspond to a hit rate of 24% and could inform the successful downstream development of a therapeutic adjunct that targets the human microbiome to prevent SAEs associated with first-line, standard-of-care anti-cancer drugs.

Skin manifestations in patients with coronavirus disease 2019

PURPOSE OF REVIEW

Coronavirus disease 2019 (COVID-19) is a well established respiratory tract illness. Recent studies in adults and children have shown an increasing number of patients reporting polymorphic cutaneous manifestations during COVID-19, including different types of rashes, from maculopapular, vascular, vesicular to atypical forms.

RECENT FINDINGS

Although pathogenesis of skin manifestations is still not fully understood, it has been proposed that cutaneous involvement during COVID-19 may be the results of the activation of the immune response against severe acute respiratory syndrome coronavirus-2, the reactivation or co-infection of herpesviruses or drug hypersensitivity.

SUMMARY

According to available literature, skin manifestations in patients with COVID-19 may be categorized on the basis of their clinical presentations as follows: erythematous rashes, lesions of vascular origin, vesicular rash, urticarial rash and acute generalized exanthematous pustulosis (AGEP), erythema multiforme and other polymorphic erythema/atypical reactions. Prompt recognition of these cutaneous manifestations represents a crucial point to facilitate diagnosis and management of COVID-19 patients.

[Diagnosis and treatment of COVID-19 in intensive care units]

Treatment of coronavirus disease 2019 (COVID-19) is particularly challenging due to the rapid scientific advances and the often significant hypoxemia. Use of high-flow oxygen, noninvasive mask ventilation, and the technique of awake proning can sometimes avoid the need for intubation. Mechanical ventilation follows the principles of ventilation for acute respiratory distress syndrome (ARDS; lung protective ventilation) and is generally supplemented by consequent positioning therapy (with at least 16 h in prone position in multiple cycles). Antiviral therapy options such as remdesivir usually come too late for patients with COVID-19 in the ICU, the only exception being the administration of monoclonal antibodies for patients without seroconversion. The value of immunomodulatory therapy such as dexamethasone is undisputed. Interleukin‑6 antagonists, on the other hand, are rather problematic for ICU patients, and for Janus kinase inhibitors, data and experience are still insufficient in this context.

Neurologic Manifestations of Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Hospitalized Patients During the First Year of the COVID-19 Pandemic

To describe the prevalence, associated risk factors, and outcomes of serious neurologic manifestations (encephalopathy, stroke, seizure, and meningitis/encephalitis) among patients hospitalized with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

DESIGN

Prospective observational study.

SETTING

One hundred seventy-nine hospitals in 24 countries within the Society of Critical Care Medicine Discovery Viral Infection and Respiratory Illness Universal Study COVID-19 Registry.

PATIENTS

Hospitalized adults with laboratory-confirmed SARS-CoV-2 infection.

INTERVENTIONS

None.

RESULTS

Of 16,225 patients enrolled in the registry with hospital discharge status available, 2,092 (12.9%) developed serious neurologic manifestations including 1,656 (10.2%) with encephalopathy at admission, 331 (2.0%) with stroke, 243 (1.5%) with seizure, and 73 (0.5%) with meningitis/encephalitis at admission or during hospitalization. Patients with serious neurologic manifestations of COVID-19 were older with median (interquartile range) age 72 years (61.0-81.0 yr) versus 61 years (48.0-72.0 yr) and had higher prevalence of chronic medical conditions, including vascular risk factors. Adjusting for age, sex, and time since the onset of the pandemic, serious neurologic manifestations were associated with more severe disease (odds ratio [OR], 1.49; p < 0.001) as defined by the World Health Organization ordinal disease severity scale for COVID-19 infection. Patients with neurologic manifestations were more likely to be admitted to the ICU (OR, 1.45; p < 0.001) and require critical care interventions (extracorporeal membrane oxygenation: OR, 1.78; p = 0.009 and renal replacement therapy: OR, 1.99; p < 0.001). Hospital, ICU, and 28-day mortality for patients with neurologic manifestations was higher (OR, 1.51, 1.37, and 1.58; p < 0.001), and patients had fewer ICU-free, hospital-free, and ventilator-free days (estimated difference in days, -0.84, -1.34, and -0.84; p < 0.001).

CONCLUSIONS

Encephalopathy at admission is common in hospitalized patients with SARS-CoV-2 infection and is associated with worse outcomes. While serious neurologic manifestations including stroke, seizure, and meningitis/encephalitis were less common, all were associated with increased ICU support utilization, more severe disease, and worse outcomes.

Rationale and design of a study to assess the safety and efficacy of rNAPc2 in COVID-19: the Phase 2b ASPEN-COVID-19 trial

Background

The interaction between thrombosis and inflammation appears central to COVID-19-associated coagulopathy and likely contributes to poor outcomes. Tissue factor is a driver of disordered coagulation and inflammatory signaling in viral infections and is important for viral replication; therefore, tissue factor may be an important therapeutic target in COVID-19.

Study Design

ASPEN-COVID-19 (NCT04655586) is a randomized, prospective open-label blinded endpoint (PROBE), active comparator Phase 2b trial to evaluate the safety and efficacy of recombinant Nematode Anticoagulant Protein c2 (rNAPc2), a potent tissue factor inhibitor, in patients hospitalized with COVID-19 with elevated D-dimer levels. This report describes the design of the Phase 2b dose ranging and proof of concept study. Participants are randomly assigned, in a 1:1:2 ratio, to lower or higher dose rNAPc2 by subcutaneous injection on days 1, 3, and 5 or to heparin according to local standard of care; randomization is stratified by baseline D-dimer level (at 2X upper limit of normal). The primary efficacy endpoint for Phase 2b is proportional change in D-dimer concentration from baseline to Day 8 or day of discharge, whichever is earlier. The primary safety endpoint is major or non-major clinically relevant bleeding through Day 8. Phase 2b enrollment began in December 2020 and is projected to complete ∼160 participants by Q4 2021.

Conclusions

ASPEN-COVID-19 will provide important data on a novel therapeutic approach that may improve outcomes in hospitalized COVID-19 patients beyond available anticoagulants by targeting tissue factor, with potential effects on not only thrombosis but also inflammation and viral propagation.

COVID-19 and the Brain

Entering the third year into the pandemic, overwhelming evidence demonstrates that Coronavirus disease 2019 (COVID-19) infection is a systemic illness, often with involvement of the central nervous system. Multiple mechanisms may underlie the development of neurologic manifestations of illness, including hypoxia, systemic illness, hypercoagulability, endothelial dysfunction, general critical illness, inflammatory response, and neurotropism of the severe acute respiratory syndrome coronavirus 2 (SARS-Co-V2) virus. COVID-19 infection is associated with neurologic involvement in all stages; acute infection, subacute/post-infection, and growing evidence also suggests during a chronic phase, the post-acute sequalae of COVID-19 (PASC). With over 20,000 published articles on COVID and the brain at the time of writing, it is virtually impossible to present an unbiased comprehensive review of how SARS-Co-V2 impacts the nervous system. In this review, we will present an overview of common neurologic manifestations, in particular focusing on the cerebrovascular complications, and proposed pathophysiology.

Human placenta-derived amniotic epithelial cells as a new therapeutic hope for COVID-19-associated acute respiratory distress syndrome (ARDS) and systemic inflammation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has become in the spotlight regarding the serious early and late complications, including acute respiratory distress syndrome (ARDS), systemic inflammation, multi-organ failure and death. Although many preventive and therapeutic approaches have been suggested for ameliorating complications of COVID-19, emerging new resistant viral variants has called the efficacy of current therapeutic approaches into question. Besides, recent reports on the late and chronic complications of COVID-19, including organ fibrosis, emphasize a need for a multi-aspect therapeutic method that could control various COVID-19 consequences. Human amniotic epithelial cells (hAECs), a group of placenta-derived amniotic membrane resident stem cells, possess considerable therapeutic features that bring them up as a proposed therapeutic option for COVID-19. These cells display immunomodulatory effects in different organs that could reduce the adverse consequences of immune system hyper-reaction against SARS-CoV-2. Besides, hAECs would participate in alveolar fluid clearance, renin-angiotensin-aldosterone system regulation, and regeneration of damaged organs. hAECs could also prevent thrombotic events, which is a serious complication of COVID-19. This review focuses on the proposed early and late therapeutic mechanisms of hAECs and their exosomes to the injured organs. It also discusses the possible application of preconditioned and genetically modified hAECs as well as their promising role as a drug delivery system in COVID-19. Moreover, the recent advances in the pre-clinical and clinical application of hAECs and their exosomes as an optimistic therapeutic hope in COVID-19 have been reviewed.

Antioxidant, anti-inflammatory and immunomodulatory roles of vitamins in COVID-19 therapy

oxidative stress is caused by an abundant generation of reactive oxygen species, associated to a diminished capacity of the endogenous systems of the organism to counteract them. Activation of pro-oxidative pathways and boosting of inflammatory cytokines are always encountered in viral infections, including SARS-CoV-2. So, the importance of counteracting cytokine storm in COVID-19 pathology is highly important, to hamper the immunogenic damage of the endothelium and alveolar membranes. Antioxidants prevent oxidative processes, by impeding radical species generation. It has been proved that vitamin intake lowers oxidative stress markers, alleviates cytokine storm and has a potential role in reducing disease severity, by lowering pro-inflammatory cytokines, hampering hyperinflammation and organ failure. For the approached compounds, direct antiviral roles are also discussed in this review, as these activities encompass secretion of antiviral peptides, modulation of angiotensin-converting enzyme 2 receptor expression and interaction with spike protein, inactivation of furin protease, or inhibition of pathogen replication by nucleic acid impairment induction. Vitamin administration results in beneficial effects. Nevertheless, timing, dosage and mutual influences of these micronutrients should be carefullly regarded.

Vasculature-on-a-chip platform with innate immunity enables identification of angiopoietin-1 derived peptide as a therapeutic for SARS-CoV-2 induced inflammation

Coronavirus disease 2019 (COVID-19) was primarily identified as a novel disease causing acute respiratory syndrome. However, as the pandemic progressed various cases of secondary organ infection and damage by severe respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported, including a breakdown of the vascular barrier. As SARS-CoV-2 gains access to blood circulation through the lungs, the virus is first encountered by the layer of endothelial cells and immune cells that participate in host defense. Here, we developed an approach to study SARS-CoV-2 infection using vasculature-on-a-chip. We first modeled the interaction of virus alone with the endothelialized vasculature-on-a-chip, followed by the studies of the interaction of the virus exposed-endothelial cells with peripheral blood mononuclear cells (PBMCs). In an endothelial model grown on a permeable microfluidic bioscaffold under flow conditions, both human coronavirus (HCoV)-NL63 and SARS-CoV-2 presence diminished endothelial barrier function by disrupting VE-cadherin junctions and elevating the level of pro-inflammatory cytokines such as interleukin (IL)-6, IL-8, and angiopoietin-2. Inflammatory cytokine markers were markedly more elevated upon SARS-CoV-2 infection compared to HCoV-NL63 infection. Introduction of PBMCs with monocytes into the vasculature-on-a-chip upon SARS-CoV-2 infection further exacerbated cytokine-induced endothelial dysfunction, demonstrating the compounding effects of inter-cellular crosstalk between endothelial cells and monocytes in facilitating the hyperinflammatory state. Considering the harmful effects of SARS-CoV-2 on endothelial cells, even without active virus proliferation inside the cells, a potential therapeutic approach is critical. We identified angiopoietin-1 derived peptide, QHREDGS, as a potential therapeutic capable of profoundly attenuating the inflammatory state of the cells consistent with the levels in non-infected controls, thereby improving the barrier function and endothelial cell survival against SARS-CoV-2 infection in the presence of PBMC.

Sustained right ventricular dysfunction in severe COVID-19: The role of disseminated intravascular coagulation

BACKGROUND

Acute right ventricular (RV) failure is common in patients hospitalized with COVID-19. Compared to the conventional echocardiographic parameters, right ventricular longitudinal strain (RVLS) is more sensitive and accurate for the diagnosis of RV systolic dysfunction.

OBJECTIVE

Our purpose was to investigate the sustained RV dysfunction echo-quantified by RVLS in patients recovered from severe COVID-19. Furthermore, we aimed to assess whether disseminated intravascular coagulation (DIC) has a key role to predict the impaired RV strain.

METHODS

Of 198 consecutive COVID-19 patients hospitalized from March 1, 2020, to April 15, 2020, 45 selected patients who survived from severe COVID-19 were enrolled in the study and referred to our echo-lab for transthoracic echocardiography 6-months after discharge. RVLS was calculated as the mean of the strain values of RV free wall. DIC was defined with a validated scoring system: DIC score equal to or more than 5 is compatible with overt-DIC. Categories of acute respiratory distress syndrome (ARDS) were defined based on PaO₂ /FiO₂ ratio.

RESULTS

A total 26 of 45 patients showed impaired RVLS at 6-months' follow-up. DIC score was significantly higher in patients with worse RVLS than in those with better RVLS (4.8 ± .5 vs. 3.6 ± .6, p =.03). Stages of ARDS did not modulate this relationship. Finally, overt-DIC results the only independent predictor of sustained RV dysfunction (OR 1.233, 95% CI 1.041-1.934, p =.043).

CONCLUSIONS

Sustained RV impairment frequently occurs in patients recovered from severe COVID-19. DIC plays a key role, resulting in an independent predictor of sustained RV dysfunction.

The Immediate Effect of COVID-19 Vaccination on Anticoagulation Control in Patients Using Vitamin K Antagonists

Background  In January 2021, the Dutch vaccination program against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was started. Clinical studies have shown that systemic reactions occur in up to 50% of vaccine recipients. Therefore, COVID-19 vaccination could affect anticoagulation control, potentially leading to an increased risk of thrombotic events and bleeding complications.

Aims  This article investigates whether the BNT162b2 vaccine affects anticoagulation control in outpatients using vitamin K antagonists (VKAs).

Methods  A case-crossover study was performed in a cohort of outpatient VKA users from four Dutch anticoagulation clinics who received a BNT162b2 vaccine. International normalized ratio (INR) results and VKA dosages before the first vaccination, the reference period, were compared with those after the first and second vaccination.

Results  A total of 3,148 outpatient VKA users were included, with a mean age (standard deviation) of 86.7 (8.7) years, of whom 43.8% were male, 67.0% used acenocoumarol, and 33.0% phenprocoumon. We observed a decrease of 8.9% of INRs within range in the standard intensity group (target INR 2.0–3.0). There was both an increased risk of supratherapeutic (odds ratio [OR] = 1.34 [95% confidence interval [CI] 1.08–1.67]) and subtherapeutic levels (OR = 1.40 [95% CI 1.08–1.83]) after first vaccination. In the high-intensity group (target INR 2.5–3.5), the risk of a supratherapeutic INR was 2.3 times higher after first vaccination (OR = 2.29 [95% CI 1.22–4.28]) and 3.3 times higher after second vaccination (OR = 3.25 [95% CI 1.06–9.97]).

Conclusion  BNT162b2 was associated with an immediate negative effect on anticoagulation control in patients treated with VKAs, so it is advisable to monitor the INR shortly after vaccination, even in stable patients.

Anticoagulants for people hospitalised with COVID-19

BACKGROUND

The primary manifestation of coronavirus disease 2019 (COVID-19) is respiratory insufficiency that can also be related to diffuse pulmonary microthrombosis and thromboembolic events, such as pulmonary embolism, deep vein thrombosis, or arterial thrombosis. People with COVID-19 who develop thromboembolism have a worse prognosis. Anticoagulants such as heparinoids (heparins or pentasaccharides), vitamin K antagonists and direct anticoagulants are used for the prevention and treatment of venous or arterial thromboembolism. Besides their anticoagulant properties, heparinoids have an additional anti-inflammatory potential. However, the benefit of anticoagulants for people with COVID-19 is still under debate.

OBJECTIVES

To assess the benefits and harms of anticoagulants versus active comparator, placebo or no intervention in people hospitalised with COVID-19.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, LILACS and IBECS databases, the Cochrane COVID-19 Study Register and medRxiv preprint database from their inception to 14 April 2021. We also checked the reference lists of any relevant systematic reviews identified, and contacted specialists in the field for additional references to trials.

SELECTION CRITERIA

Eligible studies were randomised controlled trials (RCTs), quasi-RCTs, cluster-RCTs and cohort studies that compared prophylactic anticoagulants versus active comparator, placebo or no intervention for the management of people hospitalised with COVID-19. We excluded studies without a comparator group and with a retrospective design (all previously included studies) as we were able to include better study designs. Primary outcomes were all-cause mortality and necessity for additional respiratory support. Secondary outcomes were mortality related to COVID-19, deep vein thrombosis, pulmonary embolism, major bleeding, adverse events, length of hospital stay and quality of life.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We used Cochrane RoB 1 to assess the risk of bias for RCTs, ROBINS-I to assess risk of bias for non-randomised studies (NRS) and GRADE to assess the certainty of evidence. We meta-analysed data when appropriate.

MAIN RESULTS

We included seven studies (16,185 participants) with participants hospitalised with COVID-19, in either intensive care units, hospital wards or emergency departments. Studies were from Brazil (2), Iran (1), Italy (1), and the USA (1), and two involved more than country. The mean age of participants was 55 to 68 years and the follow-up period ranged from 15 to 90 days. The studies assessed the effects of heparinoids, direct anticoagulants or vitamin K antagonists, and reported sparse data or did not report some of our outcomes of interest: necessity for additional respiratory support, mortality related to COVID-19, and quality of life. Higher-dose versus lower-dose anticoagulants (4 RCTs, 4647 participants) Higher-dose anticoagulants result in little or no difference in all-cause mortality (risk ratio (RR) 1.03, 95% CI 0.92 to 1.16, 4489 participants; 4 RCTs) and increase minor bleeding (RR 3.28, 95% CI 1.75 to 6.14, 1196 participants; 3 RCTs) compared to lower-dose anticoagulants up to 30 days (high-certainty evidence). Higher-dose anticoagulants probably reduce pulmonary embolism (RR 0.46, 95% CI 0.31 to 0.70, 4360 participants; 4 RCTs), and slightly increase major bleeding (RR 1.78, 95% CI 1.13 to 2.80, 4400 participants; 4 RCTs) compared to lower-dose anticoagulants up to 30 days (moderate-certainty evidence). Higher-dose anticoagulants may result in little or no difference in deep vein thrombosis (RR 1.08, 95% CI 0.57 to 2.03, 3422 participants; 4 RCTs), stroke (RR 0.91, 95% CI 0.40 to 2.03, 4349 participants; 3 RCTs), major adverse limb events (RR 0.33, 95% CI 0.01 to 7.99, 1176 participants; 2 RCTs), myocardial infarction (RR 0.86, 95% CI 0.48 to 1.55, 4349 participants; 3 RCTs), atrial fibrillation (RR 0.35, 95% CI 0.07 to 1.70, 562 participants; 1 study), or thrombocytopenia (RR 0.94, 95% CI 0.71 to 1.24, 2789 participants; 2 RCTs) compared to lower-dose anticoagulants up to 30 days (low-certainty evidence). It is unclear whether higher-dose anticoagulants have any effect on necessity for additional respiratory support, mortality related to COVID-19, and quality of life (very low-certainty evidence or no data). Anticoagulants versus no treatment (3 prospective NRS, 11,538 participants) Anticoagulants may reduce all-cause mortality but the evidence is very uncertain due to two study results being at critical and serious risk of bias (RR 0.64, 95% CI 0.55 to 0.74, 8395 participants; 3 NRS; very low-certainty evidence). It is uncertain if anticoagulants have any effect on necessity for additional respiratory support, mortality related to COVID-19, deep vein thrombosis, pulmonary embolism, major bleeding, stroke, myocardial infarction and quality of life (very low-certainty evidence or no data). Ongoing studies We found 62 ongoing studies in hospital settings (60 RCTs, 35,470 participants; 2 prospective NRS, 120 participants) in 20 different countries. Thirty-five ongoing studies plan to report mortality and 26 plan to report necessity for additional respiratory support. We expect 58 studies to be completed in December 2021, and four in July 2022. From 60 RCTs, 28 are comparing different doses of anticoagulants, 24 are comparing anticoagulants versus no anticoagulants, seven are comparing different types of anticoagulants, and one did not report detail of the comparator group.

AUTHORS' CONCLUSIONS

When compared to a lower-dose regimen, higher-dose anticoagulants result in little to no difference in all-cause mortality and increase minor bleeding in people hospitalised with COVID-19 up to 30 days. Higher-dose anticoagulants possibly reduce pulmonary embolism, slightly increase major bleeding, may result in little to no difference in hospitalisation time, and may result in little to no difference in deep vein thrombosis, stroke, major adverse limb events, myocardial infarction, atrial fibrillation, or thrombocytopenia.  Compared with no treatment, anticoagulants may reduce all-cause mortality but the evidence comes from non-randomised studies and is very uncertain. It is unclear whether anticoagulants have any effect on the remaining outcomes compared to no anticoagulants (very low-certainty evidence or no data). Although we are very confident that new RCTs will not change the effects of different doses of anticoagulants on mortality and minor bleeding, high-quality RCTs are still needed, mainly for the other primary outcome (necessity for additional respiratory support), the comparison with no anticoagulation, when comparing the types of anticoagulants and giving anticoagulants for a prolonged period of time.

Late retinal and optic nerve vascular complications due to COVID-19 in young individuals

Purpose

This study aims to describe the late retinal and optic nerve vascular complications due Coronavirus disease 2019 (COVID-19) in a Spanish young population.

Methods

We describe 15 eyes of 15 young patients without any other systemic risk factors, except controlled arterial hypertension in 5 of them, with the diagnosis of Central retinal vein occlusion (CRVO), Branch retinal vein occlusion (BRVO), Central retinal artery occlusion (CRAO), Branch retinal artery occlusion (BRAO), Mixed occlusions (Artery and Vein) and Non-arteritic ischemic optic neuropathy (NAION) with a previous COVID-19 infection demonstrated with a positive COVID-19 IgG Test (COVID-19 IgG/IgM Rapid Test Cassette, Lambra Laboratories, Madrid, Spain.

Results

9 males and 6 females, with a mean age of presentation of 49.7 ± 9 years old were included. The mean time between infection and diagnosis of the disease was 3.5 ± 1.2 months. The most common retinal or optic nerve vascular complication was CRVO (6 cases), following by CRAO (4 cases), Mixed arterial and venous occlusions (2 cases), NAION (2 cases) and BRAO (1 case).

Conclusions

The presence of a retinal or optic nerve vascular event in a young patient without any other hypercoagulable or genetic thrombophilic disorder, should make us rule out a previous COVID-19 infection. Ophthalmologists must be awared that retinal circulation could be another potential site for thromboembolic and optic nerve circulatory insufficiency complications of COVID-19. To our knowledge, this is the longest case series of retinal or optic nerve vascular events described after COVID-19 infection.

Investigation of CYP2E1 and Caspase-3 Gene Expressions in COVID-19 patients

Background

COVID-19 pandemic spread around the world like an infectious disease that presents waved effects on patients. Some patients needed ICU and respiratory support. Some patients only had flu-like symptoms. Cytokine storm and elevated ROS were serious problems for treatment. Apoptotic genes and CYP Family are part of these mechanisms.

Aim

In this study, our aim was to examine the gene expression CYP2E1 and Caspase-3 in patients with COVID-19 infection.

Method

60 COVID-19(+) patients (ICU and non-ICU patients) and 30 healthy volunteers were enrolled to study. To measure the level of gene expression qPCR was used. The 2-ΔΔCt method was utilized to analyze gene expression.

Results

The expression of CYP2E1 and Caspase-3 genes showed a significant discrepancy between patients and healthy individuals. Caspase-3 expression increased (p=0,0041) but CYP2E1 expression decreased (p=0,0214) in COVID-19 patients compared to healthy individuals. Both levels of gene expression were lower in patients with affected lungs than patients with unaffected lungs (p<0,05). Laboratory findings including d-Dimer, LDH, platelet count, lymphocyte count were related to both gene expressions (p<0,05). We found no correlation between CYP2E1 and Caspase-3 expressions.

Conclusion

The expression of Caspase-3 demonstrated apoptotic situations of patients but was not related to the CYP2E1 expression level. CYP2E1 gene expression is an important actor to metabolize endogens and xenobiotics however, COVID-19 patients demonstrated decreased CYP2E1 expression. CYP2E1 and Caspase-3 gene expression levels may be used as a diagnostic tool for COVID-19 patients.

A Deadly Embrace: Hemagglutination Mediated by SARS-CoV-2 Spike Protein at Its 22 N-Glycosylation Sites, Red Blood Cell Surface Sialoglycoproteins, and Antibody

Rouleaux (stacked clumps) of red blood cells (RBCs) observed in the blood of COVID-19 patients in three studies call attention to the properties of several enveloped virus strains dating back to seminal findings of the 1940s. For COVID-19, key such properties are: (1) SARS-CoV-2 binds to RBCs in vitro and also in the blood of COVID-19 patients; (2) although ACE2 is its target for viral fusion and replication, SARS-CoV-2 initially attaches to sialic acid (SA) terminal moieties on host cell membranes via glycans on its spike protein; (3) certain enveloped viruses express hemagglutinin esterase (HE), an enzyme that releases these glycan-mediated bindings to host cells, which is expressed among betacoronaviruses in the common cold strains but not the virulent strains, SARS-CoV, SARS-CoV-2 and MERS. The arrangement and chemical composition of the glycans at the 22 N-glycosylation sites of SARS-CoV-2 spike protein and those at the sialoglycoprotein coating of RBCs allow exploration of specifics as to how virally induced RBC clumping may form. The in vitro and clinical testing of these possibilities can be sharpened by the incorporation of an existing anti-COVID-19 therapeutic that has been found in silico to competitively bind to multiple glycans on SARS-CoV-2 spike protein.

Emerging Insights on Caspases in COVID-19 Pathogenesis, Sequelae, and Directed Therapies

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a significant global health emergency with new variants in some cases evading current therapies and approved vaccines. COVID-19 presents with a broad spectrum of acute and long-term manifestations. Severe COVID-19 is characterized by dysregulated cytokine release profile, dysfunctional immune responses, and hypercoagulation with a high risk of progression to multi-organ failure and death. Unraveling the fundamental immunological processes underlying the clinical manifestations of COVID-19 is vital for the identification and design of more effective therapeutic interventions for individuals at the highest risk of severe outcomes. Caspases are expressed in both immune and non-immune cells and mediate inflammation and cell death, including apoptosis and pyroptosis. Here we review accumulating evidence defining the importance of the expression and activity of caspase family members following SARS-CoV-2 infection and disease. Research suggests SARS-CoV-2 infection is linked to the function of multiple caspases, both mechanistically in vitro as well as in observational studies of individuals with severe COVID-19, which may further the impact on disease severity. We also highlight immunological mechanisms that occur in severe COVID-19 pathology upstream and downstream of activated caspase pathways, including innate recognition receptor signaling, inflammasomes, and other multiprotein complex assembly, inflammatory mediators IL-1β and IL-18, and apoptotic and pyroptotic cell death. Finally, we illuminate discriminate and indiscriminate caspase inhibitors that have been identified for clinical use that could emerge as potential therapeutic interventions that may benefit clinical efforts to prevent or ameliorate severe COVID-19.

Upper Limb Ischemia Following COVID-19 Infection: A Case Report

Introduction: COVID-19 infection can cause a wide range of complications, from respiratory infection to skin rashes. Case Presentation: Here, we report a case of a 73-year-old woman with left brachial artery thrombosis 2 weeks after the onset of COVID-19 infection, leading to left upper limb ischemia. Conclusions: Given the life-changing nature of limb ischemia that can lead to amputation, it is crucial to consider it from the beginning of COVID-19 infection and think of preventive measures in this pandemic.

Impact of Right Ventricular‐Pulmonary Circulation Coupling on Mortality in SARS‐CoV‐2 Infection

Background

The COVID‐19–related pulmonary effects may negatively impact pulmonary hemodynamics and right ventricular function. We examined the prognostic relevance of right ventricular function and right ventricular‐to‐pulmonary circulation coupling assessed by bedside echocardiography in patients hospitalized with COVID‐19 pneumonia and a large spectrum of disease independently of indices of pneumonia severity and left ventricular function.

Methods and Results

Consecutive COVID‐19 subjects who underwent full cardiac echocardiographic evaluation along with gas analyses and computed tomography scans were included in the study. Measurements were performed offline, and quantitative analyses were obtained by an operator blinded to the clinical data. We analyzed 133 patients (mean age 69±12 years, 57% men). During a mean hospital stay of 26±16 days, 35 patients (26%) died. The mean tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio was 0.48±0.18 mm/Hg in nonsurvivors and 0.72±0.32 mm/Hg in survivors (P=0.002). For each 0.1 mm/mm Hg increase in TAPSE/PASP, there was a 27% lower risk of in‐hospital death (hazard ratio [HR], 0.73 [95% CI, 0.59–0.89]; P=0.003). At multivariable analysis, TAPSE/PASP ratio remained a predictor of in‐hospital death after adjustments for age, oxygen partial pressure at arterial gas analysis/fraction of inspired oxygen, left ventricular ejection fraction, and computed tomography lung score. Receiver operating characteristic analysis was used to identify the cutoff value of the TAPSE/PASP ratio, which best specified high‐risk from lower‐risk patients. The best cutoff for predicting in‐hospital mortality was TAPSE/PASP <0.57 mm/mm Hg (75% sensitivity and 70% specificity) and was associated with a >4‐fold increased risk of in‐hospital death (HR, 4.8 [95% CI, 1.7–13.1]; P=0.007).

Conclusions

In patients hospitalized with COVID‐19 pneumonia, the assessment of right ventricular to pulmonary circulation coupling appears central to disease evolution and prediction of events. TAPSE/PASP ratio plays a mainstay role as prognostic determinant beyond markers of lung injury.