COVID-19-associated coagulopathy: An exploration of mechanisms

Acute and Chronic Effects of COVID-19 on the Cardiovascular System

COVID-19 has shown significant morbidity with the involvement of multiple systems, including the cardiovascular system. Cardiovascular manifestations in the acute phase can include myocardial injury itself, myocardial infarction, venous thromboembolic events, myocarditis, Takotsubo syndrome, and different arrhythmic events. Myocardial injury defined by the rise of cardiac biomarkers in blood has been found in multiple studies with a prevalence of about 20%. Its presence is related to worse clinical outcomes and in-hospital mortality. The mechanisms of myocardial injury have been the subject of intense research but still need to be clarified. The characterization of the cardiac affectation with echocardiography and cardiac magnetic resonance has found mixed results in different studies, with a striking incidence of imaging criteria for myocarditis. Regarding post-acute and chronic follow-up results, the persistence of symptoms and imaging changes in recovered COVID-19 patients has raised concerns about the duration and the possible significance of these findings. Even though the knowledge about this disease has increased incredibly in the last year, many aspects are still unclear and warrant further research.

Gender Characteristics of the Novel Coronavirus Infection (COVID-19) in Middle-Aged Adults

The aim of the study is to assess the gender-related specifics of the COVID-19 course in patients under 55 years of age.

Post-infection pulmonary sequelae after COVID-19 among patients with lung transplantation

BACKGROUND

There is limited data on outcomes among lung transplant (LT) patients who survive Coronavirus disease 2019 (COVID-19).

METHODS

Any single or bilateral LT patients who tested positive for SARS-CoV-2 between March 1, 2020, to February 15, 2021 (n = 54) and survived the acute illness were included (final n = 44). Each patient completed at least 3 months of follow-up (median: 4.5; range 3-12 months) after their index hospitalization for COVID-19. The primary endpoint was a significant loss of lung functions (defined as > 10% decline in forced vital capacity (FVC) or forced expiratory volume in 1 s (FEV₁ ) on two spirometries, at least 3 weeks apart compared to the pre-infection baseline).

RESULTS

A majority of the COVID-19 survivors had persistent parenchymal opacities (n = 29, 65.9%) on post-infection CT chest. Patients had significantly impaired functional status, with the majority reporting residual disabilities (Karnofsky performance scale score of 70% or worse; n = 32, 72.7%). A significant loss of lung function was observed among 18 patients (40.9%). Three patients met the criteria for new chronic lung allograft dysfunction (CLAD) following COVID-19 (5.6%), with all three demonstrating restrictive allograft syndrome phenotype. An absolute lymphocyte count < 0.6 × 10³ /dl and ferritin > 150 ng/ml at the time of hospital discharge was independently associated with significant lung function loss.

CONCLUSIONS

A significant proportion of COVID-19 survivors suffer persistent allograft injury. Low absolute lymphocyte counts (ALC) and elevated ferritin levels at the conclusion of the hospital course may provide useful prognostic information and form the basis of a customized strategy for ongoing monitoring and management of allograft dysfunction.

TWEET

Twitter handle: @AmitBangaMD Lung transplant patients who survive COVID-19 suffer significant morbidity with persistent pulmonary opacities, loss of lung functions, and functional deficits. Residual elevation of the inflammatory markers is predictive.

Pulmonary Thrombosis and Thromboembolism in COVID-19

COVID-19, the disease responsible for the devastating pandemic that began at the end of 2019, has been associated with a significantly increased risk of pulmonary thrombosis, even in patients receiving prophylactic anticoagulation. The predilection for thrombosis in COVID-19 may be driven by at least two distinct, but interrelated, processes: a hypercoagulable state responsible for large-vessel thrombosis and thromboembolism and direct vascular and endothelial injury responsible for in situ microvascular thrombosis. The presence of pulmonary thrombosis may explain why hypoxemia is out of proportion to impairment in lung compliance in some patients with COVID-19 pneumonia. Because pulmonary embolism (PE) and COVID-19 pneumonia share many signs and symptoms, diagnosing PE in patients with COVID-19 can be challenging. Given the high mortality and morbidity associated with severe COVID-19 and the concern that aspects of the disease may be driven by thrombosis, many hospital systems have instituted aggressive anticoagulation protocols above standard VTE prophylaxis. In this review, the epidemiologic and pathophysiologic features, diagnosis, and treatment of COVID-19 pulmonary thrombosis and thromboembolism are discussed.

Cardiovascular and Renal Risk Factors and Complications Associated With COVID-19

The current COVID-19 pandemic, caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) virus, represents the largest medical challenge in decades. It has exposed unexpected cardiovascular vulnerabilities at all stages of the disease (pre-infection, acute phase, and subsequent chronic phase). The major cardiometabolic drivers identified as having epidemiologic and mechanistic associations with COVID-19 are abnormal adiposity, dysglycemia, dyslipidemia, and hypertension. Hypertension is of particular interest, because components of the renin-angiotensin system (RAS), which are critically involved in the pathophysiology of hypertension, are also implicated in COVID-19. Specifically, angiotensin-converting enzyme-2 (ACE2), a multifunctional protein of the RAS, which is part of the protective axis of the RAS, is also the receptor through which SARS-CoV-2 enters host cells, causing viral infection. Cardiovascular and cardiometabolic comorbidities not only predispose people to COVID-19, but also are complications of SARS-CoV-2 infection. In addition, increasing evidence indicates that acute kidney injury is common in COVID-19, occurs early and in temporal association with respiratory failure, and is associated with poor prognosis, especially in the presence of cardiovascular risk factors. Here, we discuss cardiovascular and kidney disease in the context of COVID-19 and provide recent advances on putative pathophysiological mechanisms linking cardiovascular disease and COVID-19, focusing on the RAS and ACE2, as well as the immune system and inflammation. We provide up-to-date information on the relationships among hypertension, diabetes, and COVID-19 and emphasize the major cardiovascular diseases associated with COVID-19. We also briefly discuss emerging cardiovascular complications associated with long COVID-19, notably postural tachycardia syndrome (POTS).

Coronary microvascular dysfunction pathophysiology in COVID-19

Recently, accumulating evidence has highlighted the role of endothelial dysfunction in COVID-19 progression. Coronary microvascular dysfunction (CMD) plays a pivotal role in cardiovascular disease (CVD) and CVD-related risk factors (eg, age, gender, hypertension, diabetes mellitus, and obesity). Equally, these are also risk factors for COVID-19. The purpose of this review was to explore CMD pathophysiology in COVID-19, based on recent evidence. COVID-19 mechanisms were reviewed in terms of imbalanced renin-angiotensin-aldosterone-systems (RAAS), systemic inflammation and immune responses, endothelial dysfunction, and coagulatory disorders. Based on these mechanisms, we addressed CMD pathophysiology within the context of COVID-19, from five perspectives. The first was the disarrangement of local RAAS and Kallikrein-kinin-systems attributable to SARS-Cov-2 entry, and the concomitant decrease in coronary microvascular endothelial angiotensin I converting enzyme 2 (ACE2) levels. The second was related to coronary microvascular obstruction, induced by COVID-19-associated systemic hyper-inflammation and pro-thrombotic state. The third was focused on how pneumonia/acute respiratory distress syndrome (ARDS)-related systemic hypoxia elicited oxidative stress in coronary microvessels and cardiac sympathetic nerve activation. Fourthly, we discussed how autonomic nerve dysfunction mediated by COVID-19-associated mental, physical, or physiological factors could elicit changes in coronary blood flow, resulting in CMD in COVID-19 patients. Finally, we analyzed reciprocity between the coronary microvascular endothelium and perivascular cellular structures due to viremia, SARS-CoV-2 dissemination, and systemic inflammation. These mechanisms may function either consecutively or intermittently, finally culminating in CMD-mediated cardiovascular symptoms in COVID-19 patients. However, the underlying molecular pathogenesis remains to be clarified.

Potential Effects of Coronaviruses on the Liver: An Update

The coronaviruses that cause notable diseases, namely, severe acute respiratory syndrome (SARS), middle east respiratory syndrome (MERS) and coronavirus disease 2019 (COVID-19), exhibit remarkable similarities in genomic components and pathogenetic mechanisms. Although coronaviruses have widely been studied as respiratory tract pathogens, their effects on the hepatobiliary system have seldom been reported. Overall, the manifestations of liver injury caused by coronaviruses typically involve decreased albumin and elevated aminotransferase and bilirubin levels. Several pathophysiological hypotheses have been proposed, including direct damage, immune-mediated injury, ischemia and hypoxia, thrombosis and drug hepatotoxicity. The interaction between pre-existing liver disease and coronavirus infection has been illustrated, whereby coronaviruses influence the occurrence, severity, prognosis and treatment of liver diseases. Drugs and vaccines used for treating and preventing coronavirus infection also have hepatotoxicity. Currently, the establishment of optimized therapy for coronavirus infection and liver disease comorbidity is of significance, warranting further safety tests, animal trials and clinical trials.

Molecular Profiling of Coronavirus Disease 2019 (COVID-19) Autopsies Uncovers Novel Disease Mechanisms

Current understanding of coronavirus disease 2019 (COVID-19) pathophysiology is limited by disease heterogeneity, complexity, and a paucity of studies assessing patient tissues with advanced molecular tools. Rapid autopsy tissues were evaluated using multiscale, next-generation RNA-sequencing methods (bulk, single-nuclei, and spatial transcriptomics) to provide unprecedented molecular resolution of COVID-19-induced damage. Comparison of infected/uninfected tissues revealed four major regulatory pathways. Effectors within these pathways could constitute novel therapeutic targets, including the complement receptor C3AR1, calcitonin receptor–like receptor, or decorin. Single-nuclei RNA sequencing of olfactory bulb and prefrontal cortex highlighted remarkable diversity of coronavirus receptors. Angiotensin-converting enzyme 2 was rarely expressed, whereas basigin showed diffuse expression, and alanyl aminopeptidase, membrane, was associated with vascular/mesenchymal cell types. Comparison of lung and lymph node tissues from patients with different symptoms (one had died after a month-long hospitalization with multiorgan involvement, and the other had died after a few days of respiratory symptoms) with digital spatial profiling resulted in distinct molecular phenotypes. Evaluation of COVID-19 rapid autopsy tissues with advanced molecular techniques can identify pathways and effectors, map diverse receptors at the single-cell level, and help dissect differences driving diverging clinical courses among individual patients. Extension of this approach to larger data sets will substantially advance the understanding of the mechanisms behind COVID-19 pathophysiology.

Seaweeds and Their Natural Products for Preventing Cardiovascular Associated Dysfunction

Cardiovascular disease (CVD), which involves the onset and exacerbation of various conditions including dyslipidemia, activation of the renin-angiotensin system, vascular endothelial cell damage, and oxidative stress, is a leading cause of high mortality rates and accounts for one-third of deaths worldwide. Accordingly, as dietary changes in daily life are thought to greatly reduce the prevalence of CVD, numerous studies have been conducted to examine the potential use of foods and their bioactive components for preventing and treating CVD. In particular, seaweeds contain unique bioactive metabolites that are not found in terrestrial plants because of the harsh environment in which they survive, leading to in vitro and in vivo studies of their prevention and treatment effects. This review summarizes studies that focused on the beneficial effects of seaweeds and their natural products targeting markers involved in a cascade of mechanisms related to CVD pathogenesis. The purpose of this review is to describe the potential of seaweeds and their natural products for preventing and treating CVD based on in vivo and in vitro studies. This review provides a basis for future research in the field of marine drugs.

Role of Serum E-Selectin as a Biomarker of Infection Severity in Coronavirus Disease 2019

INTRODUCTION

E-selectin is a recognized marker of endothelial activation; however, its place in Coronavirus Disease 2019 (COVID-19) has not been fully explored. Aims of the study are to compare sE-selectin values among the Intensive Care Unit (ICU)-admitted and non-admitted, survived and non-survived patients and those with or without thrombosis.

METHODS

A single-center study of patients with COVID-19 hospitalized at Policlinico Umberto I (Rome) from March to May 2020 was performed. Simple and multiple logistic regression models were developed.

RESULTS

One hundred patients were included, with a median age (IQR) of 65 years (58-78). Twenty-nine (29%) were admitted to ICU, twenty-eight (28%) died and nineteen (19%) had a thrombotic event. The median value (IQR) of sE-selectin was 26.1 ng/mL (18.1-35). sE-selectin values did not differ between deceased and survivors (p = 0.06) and among patients with or without a thrombotic event (p = 0.22). Compared with patients who did not receive ICU treatments, patients requiring ICU care had higher levels of sE-selectin (36.6 vs. 24.1 ng/mL; p < 0.001). In the multiple logistic regression model, sE-selectin levels > 33 ng/mL, PaO2/FiO2 < 200 and PaO2/FiO2 200-300 were significantly associated with an increased risk of ICU admission. sE-selectin values significantly correlated with a neutrophil count (R = 0.32 (p = 0.001)) and the number of days from the symptoms onset to hospitalization (R = 0.28 (p = 0.004)).

CONCLUSIONS

sE-selectin levels are predictive of ICU admission in COVID-19 patients. Since data on the relation between sE-selectin and COVID-19 are scarce, this study aims to contribute toward the comprehension of the pathogenic aspects of COVID-19 disease, giving a possible clinical marker able to predict its severity.

COVID-19 susceptibility variants associate with blood clots, thrombophlebitis and circulatory diseases

Epidemiological studies suggest that individuals with comorbid conditions including diabetes, chronic lung, inflammatory and vascular disease, are at higher risk of adverse COVID-19 outcomes. Genome-wide association studies have identified several loci associated with increased susceptibility and severity for COVID-19. However, it is not clear whether these associations are genetically determined or not. We used a Phenome-Wide Association (PheWAS) approach to investigate the role of genetically determined COVID-19 susceptibility on disease related outcomes. PheWAS analyses were performed in order to identify traits and diseases related to COVID-19 susceptibility and severity, evaluated through a predictive COVID-19 risk score. We utilised phenotypic data in up to 400,000 individuals from the UK Biobank, including Hospital Episode Statistics and General Practice data. We identified a spectrum of associations between both genetically determined COVID-19 susceptibility and severity with a number of traits. COVID-19 risk was associated with increased risk for phlebitis and thrombophlebitis (OR = 1.11, p = 5.36e-08). We also identified significant signals between COVID-19 susceptibility with blood clots in the leg (OR = 1.1, p = 1.66e-16) and with increased risk for blood clots in the lung (OR = 1.12, p = 1.45 e-10). Our study identifies significant association of genetically determined COVID-19 with increased blood clot events in leg and lungs. The reported associations between both COVID-19 susceptibility and severity and other diseases adds to the identification and stratification of individuals at increased risk, adverse outcomes and long-term effects.

Evaluation of 3D-printer settings for producing personal protective equipment

Aim: COVID-19 resulted in a shortage of personal protective equipment. Community members united to 3D-print face shield headbands to support local healthcare workers. This study examined factors altering print time and strength. Materials & methods: Combinations of infill density (50%, 100%), shell thickness (0.8, 1.2 mm), line width (0.2 mm, 0.4 mm), and layer height (0.1 mm, 0.2 mm) were evaluated through tensile testing, finite element analysis, and printing time. Results: Strength increased with increased infill (p < 0.001) and shell thickness (p < 0.001). Layer height had no effect on strength. Increasing line width increased strength (p < 0.001). Discussion: Increasing layer height and line width decreased print time by 50 and 39%, respectively. Increased shell thickness did not alter print time. These changes are recommended for printing.

Acute respiratory distress syndrome: focusing on secondary injury

Acute respiratory distress syndrome (ARDS) is one of the most common severe diseases seen in the clinical setting. With the continuous exploration of ARDS in recent decades, the understanding of ARDS has improved. ARDS is not a simple lung disease but a clinical syndrome with various etiologies and pathophysiological changes. However, in the intensive care unit, ARDS often occurs a few days after primary lung injury or after a few days of treatment for other severe extrapulmonary diseases. Under such conditions, ARDS often progresses rapidly to severe ARDS and is difficult to treat. The occurrence and development of ARDS in these circumstances are thus not related to primary lung injury; the real cause of ARDS may be the “second hit” caused by inappropriate treatment. In view of the limited effective treatments for ARDS, the strategic focus has shifted to identifying potential or high-risk ARDS patients during the early stages of the disease and implementing treatment strategies aimed at reducing ARDS and related organ failure. Future research should focus on the prevention of ARDS.

The Trilogy of SARS-CoV-2 in Pediatrics (Part 3): Thrombosis, Anticoagulant, and Antiplatelet Considerations

The hypercoagulable state induced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects all patients regardless of age. The incidence of venous thromboembolism in pediatric patients with SARS-CoV-2-related illnesses is not well established. Although deep vein thrombosis is rare in children in the absence of risk factors, coagulopathy and the development of thromboses have been described in pediatric patients with acute COVID-19 and multisystem inflammatory syndrome. This comprehensive review provides a detailed overview of SARS-CoV-2-associated coagulopathy as well as strategies for optimizing the evaluation, management, and prevention of thrombosis in pediatric patients.

Nebulization with alkaline hipertonic ibuprofen induces a rapid increase in platelets circulating in COVID-19 patients but not in healthy subjects

We analyze changes in circulating platelets in COVID-19 positive patients who received conventional treatment Dexamethasone and Enoxaparin (Dexa-Enoxa) compared to patients treated with conventional therapy plus nebulization with alkaline hypertonic ibuprofenate (AHI). Results show that after 24 h of nebulization with AHI, circulating platelets shows an increase about 40% at 24 h and reach 65% at 96 h. In patients with platelets content below 200,000 by microliter the increase was 49% and 79% at 24 and 96 h respectively. In patients with platelets above 200,000 by microliter the increase was 24% and 31% at 24 and 96 h, respectively. The increase of platelets via AHI was similar in both, men and women.To evaluate whether this action of AHI was related to platelets from COVID-19 positive patients or also for healthy people, two controls were included: one of them with 10 healthy volunteers and another one with COVID-19 positive patients hospitalized and treated only with Dexa-Enoxa. Results show that, in healthy volunteers, the number of circulating platelets remains unchanged even after 7 days of treatment with AHI. In COVID-19 positive patients treated only with Dexa-Enoxa for 4 days, platelets increased only 16%.

C1-Inhibitor: Structure, Functional Diversity and Therapeutic Development

Human C1-Inhibitor (C1INH), also known as C1-esterase inhibitor, is an important multifunctional plasma glycoprotein that is uniquely involved in a regulatory network of complement, contact, coagulation, and fibrinolytic systems. C1INH belongs to a superfamily of serine proteinase inhibitor (serpins) and exhibits its inhibitory activities towards several target proteases of plasmatic cascades, operating as a major anti-inflammatory protein in the circulation. In addition to its inhibitory activities, C1INH is also involved in non-inhibitory interactions with some endogenous proteins, polyanions, cells and infectious agents. While C1INH is essential for multiple physiological processes, it is better known for its deficiency with regards to Hereditary Angioedema (HAE), a rare autosomal dominant disease clinically manifested by recurrent acute attacks of increased vascular permeability and edema. Since the link was first established between functional C1INH deficiency in plasma and HAE in the 1960s, tremendous progress has been made in the biochemical characterization of C1INH and its therapeutic development for replacement therapies in patients with C1INH-dependent HAE. Various C1INH biological activities, recent advances in the HAE-targeted therapies, and availability of C1INH commercial products have prompted intensive investigation of the C1INH potential for treatment of clinical conditions other than HAE. This article provides an updated overview of the structure and biological activities of C1INH, its role in HAE pathogenesis, and recent advances in the research and therapeutic development of C1INH; it also considers some trends for using C1INH therapeutic preparations for applications other than angioedema, from sepsis and endotoxin shock to severe thrombotic complications in COVID-19 patients.

Pulmonary Embolism Response Team utilization during the COVID-19 pandemic

Coronavirus disease 2019 (COVID-19) may predispose patients to venous thromboembolism (VTE). Limited data are available on the utilization of the Pulmonary Embolism Response Team (PERT) in the setting of the COVID-19 global pandemic. We performed a single-center study to evaluate treatment, mortality, and bleeding outcomes in patients who received PERT consultations in March and April 2020, compared to historical controls from the same period in 2019. Clinical data were abstracted from the electronic medical record. The primary study endpoints were inpatient mortality and GUSTO moderate-to-severe bleeding. The frequency of PERT utilization was nearly threefold higher during March and April 2020 (n = 74) compared to the same period in 2019 (n = 26). During the COVID-19 pandemic, there was significantly less PERT-guided invasive treatment (5.5% vs 23.1%, p = 0.02) with a numerical but not statistically significant trend toward an increase in the use of systemic fibrinolytic therapy (13.5% vs 3.9%, p = 0.3). There were nonsignificant trends toward higher in-hospital mortality or moderate-to-severe bleeding in patients receiving PERT consultations during the COVID-19 period compared to historical controls (mortality 14.9% vs 3.9%, p = 0.18 and moderate-to-severe bleeding 35.1% vs 19.2%, p = 0.13). In conclusion, PERT utilization was nearly threefold higher during the COVID-19 pandemic than during the historical control period. Among patients evaluated by PERT, in-hospital mortality or moderate-to-severe bleeding were not significantly different, despite being numerically higher, while invasive therapy was utilized less frequently during the COVID-19 pandemic.

Multiorgan thrombosis as a complication of COVID-19 pneumonia

A 47-year-old man, positive for SARS-CoV-2, was diagnosed with acute coronary syndrome (ACS) complicated by myocarditis on a background of COVID-19 pneumonia. He was medically treated for ACS; however, 3 days into his admission, the patient developed neurological complications confirmed on MRI of the brain. MRI showed established infarcts involving a large part of the left temporal lobe and right occipital lobe, with minor foci of micro-haemorrhagic transformation in the left temporal lobe. A left ventricular mural thrombus was then confirmed on echocardiogram, and this was attributed as the cause of his neurological infarct. Further infarctions in the kidneys and spleen, and thrombi in the superior mesenteric and left femoral artery were also identified on imaging of the abdomen. The left ventricular mural thrombus was removed surgically via a midline sternotomy incision under general anaesthesia. Surgery was successful and the patient was discharged to a rehabilitation centre.

Role of lungs in the hemostasis system (review of literature)

The lung tissue contains various hemostatic system elements, which can be released from the lungs, both under physiological and pathological conditions. The COVID-19 pandemic has led to an increase in the number of patients with acute respiratory distress syndrome (ARDS) in intensive care units worldwide. When the lungs are damaged, coagulation disorders are mediated by tissue factor (TF) - factor VIIa (F VIIa), and inhibition of this pathway completely eliminates intrapulmonary fibrin deposition. A tissue factor pathway inhibitor TFPI also contributes to pulmonary coagulationdisturbance in ARDS. Pulmonary coagulationdisturbance caused by pneumonia can worsen the damage to the lungs and thus contribute to the progression of the disease. Cytokines are the main linking factors between inflammation and changes in blood clotting and fibrinolysis. The sources of proinflammatory cytokines in the lungs are probably alveolar macrophages. The activation of alveolar macrophages occurs through the nuclear factor kappa-bi (NF-κB), which controls thetranscription of the expression of immune response genes, cell apoptosis, which leads to the development of inflammation and autoimmune diseases as a result of direct stimulation of TF activation. Conversely,coagulation itself can affect bronchoalveolar inflammation. Coagulation leads to the formation of proteases that interact with specific cellular receptors, activating intracellular signaling pathways. The use of anticoagulant therapy, which also has an anti-inflammatory effect, perhaps one of the therapeutic targets for coronavirus infection.The difficulty here is that it seems appropriate to study anticoagulant interventions' influence on clinically significant cardio-respiratory parameters.

Cardiovascular risk factors, cardiovascular disease, and COVID-19: an umbrella review of systematic reviews

AIMS

To consolidate evidence to determine (i) the association between cardiovascular risk factors and health outcomes with coronavirus 2019 (COVID-19); and (ii) the impact of COVID-19 on cardiovascular health.

METHODS AND RESULTS

An umbrella review of systematic reviews was conducted. Fourteen medical databases and pre-print servers were searched from 1 January 2020 to 5 November 2020. The review focused on reviews rated as moderate or high-quality using the AMSTAR 2 tool. Eighty-four reviews were identified; 31 reviews were assessed as moderate quality and one was high-quality. The following risk factors were associated with higher mortality and severe COVID-19: renal disease [odds ratio (OR) (95% confidence interval) for mortality 3.07 (2.43-3.88)], diabetes mellitus [OR 2.09 (1.80-2.42)], hypertension [OR 2.50 (2.02-3.11)], smoking history [risk ratio (RR) 1.26 (1.20-1.32)], cerebrovascular disease [RR 2.75 (1.54-4.89)], and cardiovascular disease [OR 2.65 (1.86-3.78)]. Liver disease was associated with higher odds of mortality [OR 2.81 (1.31-6.01)], but not severe COVID-19. Current smoking was associated with a higher risk of severe COVID-19 [RR 1.80 (1.14-2.85)], but not mortality. Obesity associated with higher odds of mortality [OR 2.18 (1.10-4.34)], but there was an absence of evidence for severe COVID-19. In patients hospitalized with COVID-19, the following incident cardiovascular complications were identified: acute heart failure (2%), myocardial infarction (4%), deep vein thrombosis (7%), myocardial injury (10%), angina (10%), arrhythmias (18%), pulmonary embolism (19%), and venous thromboembolism (25%).

CONCLUSION

Many of the risk factors identified as associated with adverse outcomes with COVID-19 are potentially modifiable. Primary and secondary prevention strategies that target cardiovascular risk factors may improve outcomes for people following COVID-19.

The Link between SARS-CoV-2 Infection, Inflammation and Hypercoagulability-Impact of Hemorheologic Alterations on Cardiovascular Mortality

The link between severe forms of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and cardiovascular diseases has been well documented by various studies that indicated a higher risk of cardiovascular complications in COVID-19 patients, in parallel with a higher risk of mortality in COVID-19 patients with underlying cardiovascular diseases. It seems that inflammation, which is a major pathophysiological substrate for both acute myocardial infarction and severe forms of COVID-19, may play a pivotal role in the interrelation between these two critical conditions, and hypercoagulability associated with SARS-CoV-2 infection could be responsible for acute cardiovascular complications. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) proved to be independent predictors for prognosis in acute coronary syndromes and systemic inflammatory diseases; therefore, they may be used as independent prognostic markers of disease severity in COVID-19 infection. The aim of this review is to present the most recent advances in understanding the complex link between SARS-CoV-2 infection, inflammation and alteration of blood coagulability and hemorheology, leading to major cardiovascular events.

B. Association of hypercoagulation with severe acute respiratory syndrome coronavirus 2 infection

The coronavirus disease 2019 (COVID-19) pandemic has emerged as a major threat to all healthcare systems across the globe, and it was declared a public health emergency of international concern by the World Health Organization (WHO). The novel coronavirus affects the respiratory system, producing symptoms such as fever, cough, dyspnea, and pneumonia. The association between COVID-19 and coagulation has been previously reported. Due to several inflammatory changes that occur in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections such as alterations in the levels of clotting factors, platelet activation leads to thrombus formation in coronary and cerebral vessels, leading to myocardial infarction and cerebrovascular accidents, respectively. Unfortunately, the progression of hypercoagulability in COVID-19 is rapid in patients with and without comorbidities. Hence, the proper monitoring of thrombotic complications in patients with COVID-19 is essential to avoid further complications. The implementation of guidelines for antithrombotic treatments based on the presentation of the disease is recommended. This review discusses the symptoms and mechanisms of upregulated coagulation in patients with COVID-19.

Acute upper limb arterial ischemia in patients diagnosed with COVID-19: case series

Infection by coronavirus 2, cause of the severe acute respiratory syndrome (SARS-CoV-2) in humans, was detected for the first time in Wuhan, China, in 2019, and spread globally over the course of 2020. Its different clinical manifestations are challenging, with a wide spectrum of presentations, ranging from asymptomatic infections to severe forms that can result in death. The objective of this study is to describe a series of four cases of acute arterial ischemia involving the upper limbs in patients diagnosed with COVID-19, which were managed clinically with anticoagulation, platelet antiaggregation, and prostanoids. Two patients were discharged from hospital with regression and delimitation of the ischemic zone, without needing surgical intervention, while two patients died from pulmonary complications. Adequate understanding of the pathophysiology of this disease could support better clinical management of its complications.

Broad auto-reactive IgM responses are common in critically ill patients, including those with COVID-19

The pathogenesis of severe coronavirus disease 2019 (COVID-19) remains poorly understood. While several studies suggest that immune dysregulation plays a central role, the key mediators of this process are yet to be defined. Here, we demonstrate that plasma from a high proportion (93%) of critically ill COVID-19 patients, but not healthy controls, contains broadly auto-reactive immunoglobulin M (IgM) and less frequently auto-reactive IgG or IgA. Importantly, these auto-IgMs preferentially recognize primary human lung cells in vitro, including pulmonary endothelial and epithelial cells. By using a combination of flow cytometry, analytical proteome microarray technology, and lactose dehydrogenase (LDH)-release cytotoxicity assays, we identify high-affinity, complement-fixing, auto-reactive IgM directed against 260 candidate autoantigens, including numerous molecules preferentially expressed on the cellular membranes of pulmonary, vascular, gastrointestinal, and renal tissues. These findings suggest that broad IgM-mediated autoimmune reactivity may be involved in the pathogenesis of severe COVID-19, thereby identifying a potential target for therapeutic interventions.

Preventive effects of Pycnogenol® on cardiovascular risk factors (including endothelial function) and microcirculation in subjects recovering from coronavirus disease 2019 (COVID-19)

BACKGROUND

The aim of this open supplement study was to evaluate the effects of Pycnogenol® in comparison with controls on symptoms of post-COVID-19 syndrome and in improving endothelial function, microcirculation, inflammatory markers and oxidative stress over 3 months in symptomatic subjects recovering from COVID-19.

METHODS

Sixty subjects recovering from symptomatic COVID-19 were included. One group of 30 followed a standard recovery management while 30 comparable subjects received a supplement of 150 mg Pycnogenol® daily (in 3 doses of 50 mg) in addition to standard management.

RESULTS

Two groups of selected subjects were comparable at baseline. The groups progressively improved both with the SM (standard management) and with the SM in combination with the supplement. Patients, supplemented with Pycnogenol® showed significantly better improvement compared to the control group patients. No side effects from the supplementation were observed; tolerability was optimal. The progressive evolution over time was visible in all target measurements. Physiological tests. Endothelial function, low in all subjects at inclusion was assessed by flow mediated dilation (FMD) and finger reactive hyperemia in the microcirculation (laser Doppler measurements) after the release of an occluding suprasystolic cuff). It was significantly improved in the Pycnogenol® group after one month and after 3 months (p<0.05 vs controls). The rate of ankle swelling (RAS) by strain gauge decreased significantly in the supplemented group (p<0.05) in comparison with controls showing an improvement of the capillary filtration rate. At inclusion, the kidney cortical flow velocity indicated a decrease in perfusion (lower systolic and diastolic flow velocity) in all patients. Kidney cortical flow velocity increased significantly with the supplement (p<0.05) in comparison with controls with improvement in systolic velocity and in diastolic component. High sensitivity CRP (hs-CRP) and Il-6 plasma levels decreased progressively over 3 months with a significant more pronounced decrease in the supplement group (p<0.05). The number of patients with normal plasma IL-6 levels at the end of the study was higher (p<0,05) with the supplement. ESR followed the same pattern with a progressive and a more significant decrease in the supplemented subjects (p<0.02). Oxidative stress decreased significantly in the supplemented group (p<0.05) compared with the control group. Blood pressure and heart rate were normalized in all subjects in the supplement group; systolic pressure was significantly lower in the supplemented group (p<0,05) at the end of the study. Finally, the scores of Quality-of-life, mood and fatigue questionnaire and the Karnofsky scale performance index significantly improved in the supplement group (p<0.05) compared to controls after 1 and 3 months. All other blood parameters (including platelets and clotting factors) were within normal values at the end of the study.

CONCLUSIONS

In conclusion, Pycnogenol® may offer a significant option for managing some of the signs and symptoms associated with post-COVID-19 syndrome. This pilot evaluation offers some potential rationale for the use of Pycnogenol® in this condition that will have significant importance in the coming years.

A potential association between immunosenescence and high COVID-19 related mortality among elderly patients with cardiovascular diseases

Elderly patients with cardiovascular diseases account for a large proportion of Corona virus Disease 2019(COVID-19)related deaths. COVID-19, as a new coronavirus, mainly targets the patient's lung triggering a cascade of innate and adaptive immune responses in the host. The principal causes of death among COVID-19 patients, especially elderly subjects with cardiovascular diseases, are acute respiratory distress syndrome(ARDS), multiple organ dysfunction syndrome (MODS), and microvascular thrombosis. All prompted by an excessive uncontrolled systemic inflammatory response. Immunosenescence, characterized by systemic and chronic inflammation as well as innate/adaptive immune imbalance, presents both in the elderly and cardiovascular patients. COVID-19 infection further aggravates the existing inflammatory process and lymphocyte depletion leading to uncontrollable systemic inflammatory responses, which is the primary cause of death. Based on the higher mortality, this study attempts to elucidate the pathophysiological mechanisms of COVID-19 in elderly subjects with cardiovascular diseases as well as the cause of the high mortality result from COVID-19.

The Notch Pathway: A Link Between COVID-19 Pathophysiology and Its Cardiovascular Complications

COVID-19 is associated with a large number of cardiovascular sequelae, including dysrhythmias, myocardial injury, myocarditis and thrombosis. The Notch pathway is one likely culprit leading to these complications due to its direct role in viral entry, inflammation and coagulation processes, all shown to be key parts of COVID-19 pathogenesis. This review highlights links between the pathophysiology of SARS-CoV2 and the Notch signaling pathway that serve as primary drivers of the cardiovascular complications seen in COVID-19 patients.

Neuroimaging Patterns in Patients with COVID-19-Associated Neurological Complications: A Review

Background

A variety of neuroimaging abnormalities in COVID-19 have been described.

Objectives

In this article, we reviewed the varied neuroimaging patterns in patients with COVID-19-associated neurological complications.

Methods

We searched PubMed, Google Scholar, Scopus and preprint databases (medRxiv and bioRxiv). The search terms we used were "COVID -19 and encephalitis, encephalopathy, neuroimaging or neuroradiology" and "SARS-CoV-2 and encephalitis, encephalopathy, neuroimaging or neuroradiology".

Results

Neuroimaging abnormalities are common in old age and patients with comorbidities. Neuroimaging abnormalities are largely vascular in origin. COVID-19-associated coagulopathy results in large vessel occlusion and cerebral venous thrombosis. COVID-19-associated intracerebral hemorrhage resembles anticoagulant associated intracerebral hemorrhage. On neuroimaging, hypoxic-ischemic damage along with hyperimmune reaction against the SARS-COV-2 virus manifests as small vessel disease. Small vessel disease appears as diffuse leukoencephalopathy and widespread microbleeds, and subcortical white matter hyperintensities. Occasionally, gray matter hyperintensity, similar to those observed seen in autoimmune encephalitis, has been noted. In many cases, white matter lesions similar to that in acute disseminated encephalomyelitis have been described. Acute disseminated encephalomyelitis in COVID-19 seems to be a parainfectious event and autoimmune in origin. Many cases of acute necrotizing encephalitis resulting in extensive damage to thalamus and brain stem have been described; cytokine storm has been considered a pathogenic mechanism behind this. None of the neuroimaging abnormalities can provide a clue to the possible pathogenic mechanism.

Conclusions

Periventricular white-matter MR hyperintensity, microbleeds, arterial and venous infarcts, and hemorrhages are apparently distinctive neuroimaging abnormalities in patients with COVID-19.

Tie2 activation protects against prothrombotic endothelial dysfunction in COVID-19

Profound endothelial dysfunction accompanies the microvascular thrombosis commonly observed in severe COVID-19. In the quiescent state, the endothelial surface is anticoagulant, a property maintained at least in part via constitutive signaling through the Tie2 receptor. During inflammation, the Tie2 antagonist angiopoietin-2 (Angpt-2) is released from activated endothelial cells and inhibits Tie2, promoting a prothrombotic phenotypic shift. We sought to assess whether severe COVID-19 is associated with procoagulant dysfunction of the endothelium and alterations in the Tie2-angiopoietin axis. Primary human endothelial cells treated with plasma from patients with severe COVID-19 upregulated the expression of thromboinflammatory genes, inhibited expression of antithrombotic genes, and promoted coagulation on the endothelial surface. Pharmacologic activation of Tie2 with the small molecule AKB-9778 reversed the prothrombotic state induced by COVID-19 plasma in primary endothelial cells. On lung autopsy specimens from COVID-19 patients, we found a prothrombotic endothelial signature as evidenced by increased von Willebrand Factor and loss of anticoagulant proteins. Assessment of circulating endothelial markers in a cohort of 98 patients with mild, moderate, or severe COVID-19 revealed profound endothelial dysfunction indicative of a prothrombotic state. Angpt-2 concentrations rose with increasing disease severity and highest levels were associated with worse survival. These data highlight the disruption of Tie2-angiopoietin signaling and procoagulant changes in endothelial cells in severe COVID-19. Moreover, our findings provide novel rationale for current trials of Tie2 activating therapy with AKB-9778 in severe COVID-19 disease.

COVID-19-related Multisystem Inflammatory Syndrome in a Young Adult

Introduction

A condition called multisystem inflammatory syndrome in children (MIS-C), related to past SARS-CoV-2 infection, has been described in a series of cases. There is a growing body of evidence suggesting a similar entity in adults (MIS-A). We report a case of a young adult with a hyperinflammatory systemic syndrome with end-organ lesions and a recent SARS-CoV-2 infection.

Methods and Procedures

The patient developed end-organ lesions in the respiratory, cardiovascular, digestive, haematological and mucocutaneous systems. A wide diagnostic work-up did not find any specific aetiology (autoimmunity, neoplastic or infectious). There was evidence of past SARS-CoV-2 infection with positive autoimmune titres (positive IgG). A presumptive diagnosis of MIS-A was made and treatment with corticosteroids was introduced with improvement.

Discussion

COVID-19-related multisystem inflammatory syndrome in adults is still an unknown entity with no diagnostic criteria or treatment guidelines. Much of what is known is inferred from what we already know about MIS-C. There have been several reported cases with severity ranging from mild to severe. The mechanisms behind this condition are still largely unknown. More evidence is needed to establish diagnosis and treatment.

LEARNING POINTS

COVID-19-related multisystem inflammatory syndrome in adults is a new entity with few case reports.Awareness is important for early diagnosis and treatment.

2019 Coronavirus disease (COVID-19): contribution of rheumatology

The 2019 coronavirus disease (COVID-19) pandemic become a major challenge for humanity and a unique opportunity to get an idea of the real achievements of modern biology and medicine. In the course of the pandemic, a large number of new fundamental and medical issues have been revealed regarding the relationship between viral infection and many common chronic non-infectious diseases, among which immune-mediated rheumatic diseases (IMRD) occupy an important position. It is now well known that SARS-CoV-2 infection is accompanied by a wide range of extrapulmonary clinical and laboratory disorders, some of which are characteristic of IMRD and other autoimmune and autoinflammatory diseases in humans. The most severe consequence of alterations in regulation of the immunity in COVID-19 and IMRD is the so-called cytokine storm syndrome, which is defined as COVID-19-associated hyperinflammatory syndrome in COVID-19, and as macrophage activation syndrome in IMRD. The COVID-19-associated hyperinflammatory syndrome was used as a reason for drug repurposing and off-label use of a wide range of anti-inflammatory drugs, which have been specially developed for the treatment of IMRD over the past 20 years. Common immunopathological mechanisms and approaches to pharmacotherapy in COVID-19 and IMRD determined the unique place of rheumatology among medical specialties contributing to combat the COVID-19 pandemic. The article provides the basic provisions of the International and National Association of Rheumatologists and the Association of Rheumatologists of Russia (ARR) recommendations for management of patients with IMRD during the COVID-19 pandemic.

Endothelial Dysfunction and SARS-CoV-2 Infection: Association and Therapeutic Strategies

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), has been recently considered a systemic disorder leading to the procoagulant state. Preliminary studies have shown that SARS-CoV-2 can infect endothelial cells, and extensive evidence of inflammation and endothelial dysfunction has been found in advanced COVID-19. Endothelial cells play a critical role in many physiological processes, such as controlling blood fluidity, leukocyte activation, adhesion, platelet adhesion and aggregation, and transmigration. Therefore, it is reasonable to think that endothelial dysfunction leads to vascular dysfunction, immune thrombosis, and inflammation associated with COVID-19. This article summarizes the association of endothelial dysfunction and SARS-CoV-2 infection and its therapeutic strategies.

Endothelial Dysfunction in the Brain: Setting the Stage for Stroke and Other Cerebrovascular Complications of COVID-19

The Coronavirus disease 2019 (COVID)-19 pandemic has already affected millions worldwide, with a current mortality rate of 2.2%. While it is well-established that severe acute respiratory syndrome-coronavirus-2 causes upper and lower respiratory tract infections, a number of neurological sequelae have now been reported in a large proportion of cases. Additionally, the disease causes arterial and venous thromboses including pulmonary embolism, myocardial infarction, and a significant number of cerebrovascular complications. The increasing incidence of large vessel ischemic strokes as well as intracranial hemorrhages, frequently in younger individuals, and associated with increased morbidity and mortality, has raised questions as to why the brain is a major target of the disease. COVID-19 is characterized by hypercoagulability with alterations in hemostatic markers including high D-dimer levels, which are a prognosticator of poor outcome. Together with findings of fibrin-rich microthrombi, widespread extracellular fibrin deposition in affected various organs and hypercytokinemia, this suggests that COVID-19 is more than a pulmonary viral infection. Evidently, COVID-19 is a thrombo-inflammatory disease. Endothelial cells that constitute the lining of blood vessels are the primary targets of a thrombo-inflammatory response, and severe acute respiratory syndrome coronavirus 2 also directly infects endothelial cells through the ACE2 (angiotensin-converting enzyme 2) receptor. Being highly heterogeneous in their structure and function, differences in the endothelial cells may govern the susceptibility of organs to COVID-19. Here, we have explored how the unique characteristics of the cerebral endothelium may be the underlying reason for the increased rates of cerebrovascular pathology associated with COVID-19.

Treatment of COVID-19 by stage: any space left for mesenchymal stem cell therapy?

In many countries, COVID-19 now accounts for more deaths per year than car accidents and even the deadliest wars. Combating the viral pandemics requires a coordinated effort to develop therapeutic protocols adaptable to the disease severity. In this review article, we summarize a graded approach aiming to shield cells from SARS-CoV-2 entry and infection, inhibit excess inflammation and evasion of the immune response, and ultimately prevent systemic organ failure. Moreover, we focus on mesenchymal stem cell therapy, which has shown safety and efficacy as a treatment of inflammatory and immune diseases. The cell therapy approach is now repurposed in patients with severe COVID-19. Numerous trials of mesenchymal stem cell therapy are ongoing, especially in China and the USA. Leader companies in cell therapy have also started controlled trials utilizing their quality assessed cell products. Results are too premature to reach definitive conclusions.

Prevalence of Venous Thromboembolism in Critically Ill Patients With Coronavirus Disease 2019: A Meta-Analysis

Background: Accumulating evidence suggests that coronavirus disease 2019 (COVID-19) is associated with hypercoagulative status, particularly for critically ill patients in the intensive care unit. However, the prevalence of venous thromboembolism (VTE) in these patients under routine prophylactic anticoagulation remains unknown. A meta-analysis was performed to evaluate the prevalence of VTE in these patients by pooling the results of these observational studies. Methods: Observational studies that reported the prevalence of VTE in critically ill patients with COVID-19 were identified by searching the PubMed and Embase databases. A random-effect model was used to pool the results by incorporating the potential heterogeneity. Results: A total of 19 studies with 1,599 patients were included. The pooled results revealed that the prevalence of VTE, deep venous thrombosis (DVT), and pulmonary embolism (PE) in critically ill patients with COVID-19 was 28.4% [95% confidence interval (CI): 20.0-36.8%], 25.6% (95% CI: 17.8-33.4%), and 16.4% (95% CI: 10.1-22.7%), respectively. Limited to studies, in which all patients received routine prophylactic anticoagulation, and the prevalence for VTE, DVT, and PE was 30.1% (95% CI: 19.4-40.8%), 27.2% (95% CI: 16.5-37.9%), and 18.3% (95% CI: 9.8%-26.7%), respectively. The prevalence of DVT was higher in studies with routine screening for all patients, when compared to studies with screening only in clinically suspected patients (47.5% vs. 15.1%, P < 0.001). Conclusion: Critically ill patients with COVID-19 have a high prevalence of VTE, despite the use of present routine prophylactic anticoagulation.

Unilateral common carotid artery dissection in a patient with recent COVID-19: An association or a coincidence?

The "Corona Virus Disease 2019 (COVID-19)", caused by severe acute respiratory coronavirus 2 (SARS-CoV-2), progressed rapidly since its first outbreak, and quickly developed into a pandemic. Although COVID-19 mostly presents with respiratory symptoms, researchers have started reporting neurologic manifestations such as cerebrovascular diseases in patients, with COVID-19 as the pandemic has progressed. Herein, we report a case of 38-year-old female patient identified with a left common carotid artery dissection, with COVID-19. Clinicians must keep in mind that COVID-19 can cause vascular complications such as carotid artery dissections in the ensuing period, even after the acute phase, although there is currently a lack of sufficient evidence to identify any causal association between COVID-19 and arterial dissections.

Transcriptional Regulation of Thrombin-Induced Endothelial VEGF Induction and Proangiogenic Response

Thrombin, the ligand of the protease-activated receptor 1 (PAR1), is a well-known stimulator of proangiogenic responses in vascular endothelial cells (ECs), which are mediated through the induction of vascular endothelial growth factor (VEGF). However, the transcriptional events underlying this thrombin-induced VEGF induction and angiogenic response are less well understood at present. As reported here, we conducted detailed promotor activation and signal transduction pathway studies in human microvascular ECs, to decipher the transcription factors and the intracellular signaling events underlying the thrombin and PAR-1-induced endothelial VEGF induction. We found that c-FOS is a key transcription factor controlling thrombin-induced EC VEGF synthesis and angiogenesis. Upon the binding and internalization of its G-protein-coupled PAR-1 receptor, thrombin triggers ERK1/2 signaling and activation of the nuclear AP-1/c-FOS transcription factor complex, which then leads to VEGF transcription, extracellular secretion, and concomitant proangiogenic responses of ECs. In conclusion, exposure of human microvascular ECs to thrombin triggers signaling through the PAR-1–ERK1/2–AP-1/c-FOS axis to control VEGF gene transcription and VEGF-induced angiogenesis. These observations offer a greater understanding of endothelial responses to thromboinflammation, which may help to interpret the results of clinical trials tackling the conditions associated with endothelial injury and thrombosis.

Prognostic value of thrombin generation parameters in hospitalized COVID-19 patients

SARS-CoV-2 infection increases the risk of thrombosis by different mechanisms not fully characterized. Although still debated, an increase in D-dimer has been proposed as a first-line hemostasis test associated with thromboembolic risk and unfavorable prognosis. We aim to systematically and comprehensively evaluate the association between thrombin generation parameters and the inflammatory and hypercoagulable state, as well as their prognostic value in COVID-19 patients. A total of 127 hospitalized patients with confirmed COVID-19, 24 hospitalized patients with SARS-CoV-2-negative pneumonia and 12 healthy subjects were included. Clinical characteristics, thrombin generation triggered by tissue factor with and without soluble thrombomodulin, and also by silica, as well as other biochemical parameters were assessed. Despite the frequent use of heparin, COVID-19 patients had similar thrombin generation to healthy controls. In COVID-19 patients, the thrombin generation lag-time positively correlated with markers of cell lysis (LDH), inflammation (CRP, IL-6) and coagulation (D-dimer), while the endogenous thrombin potential (ETP) inversely correlated with D-dimer and LDH, and positively correlated with fibrinogen levels. Patients with more prolonged lag-time and decreased ETP had higher peak ISTH-DIC scores, and had more severe disease (vascular events and death). The ROC curve and Kaplan Meier estimate indicated that the D-dimer/ETP ratio was associated with in-hospital mortality (HR 2.5; p = 0.006), and with the occurrence of major adverse events (composite end-point of vascular events and death) (HR 2.38; p = 0.004). The thrombin generation ETP and lag-time variables correlate with thromboinflammatory markers, and the D-dimer/ETP ratio can predict major adverse events in COVID-19.

The SARS-CoV-2 as an instrumental trigger of autoimmunity

Autoimmunity may be generated by a variety of factors by creating a hyper-stimulated state of the immune system. It had been established long ago that viruses are a substantial component of environmental factors that contribute to the production of autoimmune antibodies, as well as autoimmune diseases. Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human immunodeficiency virus (HIV) are viruses that withhold these autoimmune abilities. In a similar manner, SARS-CoV-2 may be counted to similar manifestations, as numerous records demonstrating the likelihood of COVID-19 patients to develop multiple types of autoantibodies and autoimmune diseases. In this review, we focused on the association between COVID-19 and the immune system concerning the tendency of patients to develop over 15 separate types of autoantibodies and above 10 distinct autoimmune diseases. An additional autoimmunity manifestation may be one of the common initial symptoms in COVID-19 patients, anosmia, the complete loss of the ability to sense smell, and other olfactory alterations. We summarize current knowledge on principal mechanisms that may contribute to the development of autoimmunity in the disease: the ability of SARS-CoV-2 to hyper-stimulate the immune system, induce excessive neutrophil extracellular traps formation with neutrophil-associated cytokine responses and the molecular resemblance between self-components of the host and the virus. Additionally, we will examine COVID-19 potential risk on the new-onsets of autoimmune diseases, such as antiphospholipid syndrome, Guillain-Barré syndrome, Kawasaki disease and numerous others. It is of great importance to recognize those autoimmune manifestations of COVID-19 in order to properly cope with their outcomes in the ongoing pandemic and the long-term post-pandemic period. Lastly, an effective vaccine against SARS-CoV-2 may be the best solution in dealing with the ongoing pandemic. We will discuss the new messenger RNA vaccination strategy with an emphasis on autoimmunity implications.

Fibrinolytic Serine Proteases, Therapeutic Serpins and Inflammation: Fire Dancers and Firestorms

The making and breaking of clots orchestrated by the thrombotic and thrombolytic serine protease cascades are critical determinants of morbidity and mortality during infection and with vascular or tissue injury. Both the clot forming (thrombotic) and the clot dissolving (thrombolytic or fibrinolytic) cascades are composed of a highly sensitive and complex relationship of sequentially activated serine proteases and their regulatory inhibitors in the circulating blood. The proteases and inhibitors interact continuously throughout all branches of the cardiovascular system in the human body, representing one of the most abundant groups of proteins in the blood. There is an intricate interaction of the coagulation cascades with endothelial cell surface receptors lining the vascular tree, circulating immune cells, platelets and connective tissue encasing the arterial layers. Beyond their role in control of bleeding and clotting, the thrombotic and thrombolytic cascades initiate immune cell responses, representing a front line, "off-the-shelf" system for inducing inflammatory responses. These hemostatic pathways are one of the first response systems after injury with the fibrinolytic cascade being one of the earliest to evolve in primordial immune responses. An equally important contributor and parallel ancient component of these thrombotic and thrombolytic serine protease cascades are the serine protease inhibitors, termed serpins. Serpins are metastable suicide inhibitors with ubiquitous roles in coagulation and fibrinolysis as well as multiple central regulatory pathways throughout the body. Serpins are now known to also modulate the immune response, either via control of thrombotic and thrombolytic cascades or via direct effects on cellular phenotypes, among many other functions. Here we review the co-evolution of the thrombolytic cascade and the immune response in disease and in treatment. We will focus on the relevance of these recent advances in the context of the ongoing COVID-19 pandemic. SARS-CoV-2 is a "respiratory" coronavirus that causes extensive cardiovascular pathogenesis, with microthrombi throughout the vascular tree, resulting in severe and potentially fatal coagulopathies.

Fibrinolysis Shutdown in COVID-19: Clinical Manifestations, Molecular Mechanisms, and Therapeutic Implications

The COVID-19 pandemic has introduced a global public health threat unparalleled in our history. The most severe cases are marked by ARDS attributed to microvascular thrombosis. Hypercoagulability, resulting in a profoundly prothrombotic state, is a distinct feature of COVID-19 and is accentuated by a high incidence of fibrinolysis shutdown. The aims of this review were to describe the manifestations of fibrinolysis shutdown in COVID-19 and its associated outcomes, review the molecular mechanisms of dysregulated fibrinolysis associated with COVID-19, and discuss potential implications and therapeutic targets for patients with severe COVID-19.

Possible role of purinergic signaling in COVID-19

The coronavirus disease (COVID-19), caused by SARS-CoV-2 infection, accounts for more than 2.4 million deaths worldwide, making it the main public health problem in 2020. Purinergic signaling is involved in the pathophysiology of several viral infections which makes the purinergic system a potential target of investigation in COVID-19. During viral infections, the ATP release initiates a cascade that activates purinergic receptors. This receptor activation enhances the secretion of pro-inflammatory cytokines and performs the chemotaxis of macrophages and neutrophils, generating an association between the immune and the purinergic systems. This review was designed to cover the possible functions of purinergic signaling in COVID-19, focusing on the possible role of purinergic receptors such as P2X7 which contributes to cytokine storm and inflammasome NLRP3 activation and P2Y1 that activates the blood coagulation pathway. The possible role of ectonucleotidases, such as CD39 and CD73, which have the function of dephosphorylating ATP in an immunosuppressive component, adenosine, are also covered in detail. Moreover, therapeutic combination or association possibilities targeting purinergic system components are also suggested as a possible useful tool to be tested in future researches, aiming to unveil a novel option to treat COVID-19 patients.

A Comprehensive Analysis of Maternal and Newborn Disease and Related Control for COVID-19

The maternal-fetal/newborn unit is established at risk for COVID-19 infection. This narrative review summarizes the contemporary and cumulative publications which detail maternal infection, antenatal and newborn infections, and maternal/fetal/newborn management and prevention. There is a wide spectrum of maternal disease, but the potential for severe disease albeit in a minority is confirmed. COVID-19 carries risk for preterm delivery. Pregnant females can suffer multisystem disease, and co-morbidities play a significant role in risk. Congenital infection has been supported by several anecdotal reports, but strong confirmatory data are few. No typical congenital dysmorphisms are evident. Nevertheless, placental vascular compromise must be considered a risk for the fetus during advanced maternal infections. Clinical manifestations of newborn infection have been mild to moderate and relatively uncommon. Proven antiviral therapy is of yet lacking. The mode of delivery is a medical decision that must include patient risk assessment and patient directives. Both presymptomatic and asymptomatic mothers and offspring can complicate infection control management with the potential for spread to others in several regards. In the interim, infections of the maternal-fetal-newborn unit must be taken seriously both for the disease so caused and the potential for further dissemination of disease.

Bidirectional link between diabetes mellitus and coronavirus disease 2019 leading to cardiovascular disease: A narrative review

Coronavirus disease 2019 (COVID-19) is a global pandemic where several comorbidities have been shown to have a significant effect on mortality. Patients with diabetes mellitus (DM) have a higher mortality rate than non-DM patients if they get COVID-19. Recent studies have indicated that patients with a history of diabetes can increase the risk of severe acute respiratory syndrome coronavirus 2 infection. Additionally, patients without any history of diabetes can acquire new-onset DM when infected with COVID-19. Thus, there is a need to explore the bidirectional link between these two conditions, confirming the vicious loop between "DM/COVID-19". This narrative review presents (1) the bidirectional association between the DM and COVID-19, (2) the manifestations of the DM/COVID-19 loop leading to cardiovascular disease, (3) an understanding of primary and secondary factors that influence mortality due to the DM/COVID-19 loop, (4) the role of vitamin-D in DM patients during COVID-19, and finally, (5) the monitoring tools for tracking atherosclerosis burden in DM patients during COVID-19 and "COVID-triggered DM" patients. We conclude that the bidirectional nature of DM/COVID-19 causes acceleration towards cardiovascular events. Due to this alarming condition, early monitoring of atherosclerotic burden is required in "Diabetes patients during COVID-19" or "new-onset Diabetes triggered by COVID-19 in Non-Diabetes patients".