Coagulopathy, thromboembolic complications, and the use of heparin in COVID-19 pneumonia

Control of tissue homeostasis by the extracellular matrix: Synthetic heparan sulfate as a promising therapeutic for periodontal health and bone regeneration

Proteoglycans are core proteins associated with carbohydrate/sugar moieties that are highly variable in disaccharide composition, which dictates their function. These carbohydrates are named glycosaminoglycans, and they can be attached to proteoglycans or found free in tissues or on cell surfaces. Glycosaminoglycans such as hyaluronan, chondroitin sulfate, dermatan sulfate, keratan sulfate, and heparin/heparan sulfate have multiple functions including involvement in inflammation, immunity and connective tissue structure, and integrity. Heparan sulfate is a highly sulfated polysaccharide that is abundant in the periodontium including alveolar bone. Recent evidence supports the contention that heparan sulfate is an important player in modulating interactions between damage associated molecular patterns and inflammatory receptors expressed by various cell types. The structure of heparan sulfate is reported to dictate its function, thus, the utilization of a homogenous and structurally defined heparan sulfate polysaccharide for modulation of cell function offers therapeutic potential. Recently, a chemoenzymatic approach was developed to allow production of many structurally defined heparan sulfate carbohydrates. These oligosaccharides have been studied in various pathological inflammatory conditions to better understand their function and their potential application in promoting tissue homeostasis. We have observed that specific size and sulfation patterns can modulate inflammation and promote tissue maintenance including an anabolic effect in alveolar bone. Thus, new evidence provides a strong impetus to explore heparan sulfate as a potential novel therapeutic agent to treat periodontitis, support alveolar bone maintenance, and promote bone formation.

Drugs for COVID-19: An Update

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was the seventh known human coronavirus, and it was identified in Wuhan, Hubei province, China, in 2020. It caused the highly contagious disease called coronavirus disease 2019 (COVID-19), declared a global pandemic by the World Health Organization (WHO) on 11 March 2020. A great number of studies in the search of new therapies and vaccines have been carried out in these three long years, producing a series of successes; however, the need for more effective vaccines, therapies and other solutions is still being pursued. This review represents a tracking shot of the current pharmacological therapies used for the treatment of COVID-19.

Low molecular weight heparin is associated with better outcomes than unfractionated heparin for thromboprophylaxis in hospitalized COVID-19 patients: a meta-analysis

AIMS

This study aimed to compare the outcomes of the administration of LMWH and UFH in hospitalized COVID-19 patients.

METHODS AND RESULTS

We systematically searched several databases and included observational studies or clinical trials that compared the outcomes of the administration of LMWH and UFH in hospitalized COVID-19 patients. A total of nine studies comprising 9637 patients were included. Metanalysis showed that LMWH administration was associated with a lower in-hospital mortality and 28/30-day mortality compared with UFH administration {[relative risk (RR) 0.44; 95% confidence interval (95% CI) 0.32-0.61; I2: 87.9%] and (RR 0.45; 95% CI 0.24-0.86; I2: 78.4%), respectively}. Patient with LMWH had shorter duration of hospital and ICU length of stay compared with UFH {[weighted mean difference (WMD) -2.20; 95% CI -3.01 to -1.40; I2:0%] and (WMD -1.41; 95% CI -2.20 to -0.63; I2: 0%), respectively}. The risk of ICU admission or mechanical ventilation was lower in patients who received LMWH than in those who received UFH (RR 0.67; 95% CI 0.55-0.81; I2: 67.3%). However, there was no difference in the incidence of bleeding with LMWH compared with UFH (RR 0.27; 95% CI 0.07-1.01; I2: 64.6%).

CONCLUSION

Our meta-analysis showed that administration of LMWH was associated with better outcomes compared with UFH in hospitalized COVID-19 patients. Prospective cohorts and RCTs are urgently needed to explore the definitive effect of LMWH to provide direct high-certainty evidence. PROSPERO registration number: CRD42021271977.

The Role of Heparin in COVID-19: An Update after Two Years of Pandemics

Coronavirus disease 2019 (COVID-19) is associated with an increased risk of venous thromboembolism (VTE) and coagulopathy, especially in critically ill patients. Endothelial damage induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is emerging as a crucial pathogenetic mechanism for the development of complications in an acute phase of the illness and for several postdischarge sequalae. Heparin has been shown to have a positive impact on COVID-19 due to its anticoagulant function. Moreover, several other biological actions of heparin were postulated: a potential anti-inflammatory and antiviral effect through the main protease (Mpro) and heparansulfate (HS) binding and a protection from the damage of vascular endothelial cells. In this paper, we reviewed available evidence on heparin treatment in COVID-19 acute illness and chronic sequalae, focusing on the difference between prophylactic and therapeutic dosage.

Occurrence, Fate, Effects, and Risks of Dexamethasone: Ecological Implications Post-COVID-19

The recent outbreak of respiratory syndrome-coronavirus-2 (SARS-CoV-2), which causes coronavirus disease (COVID-19), has led to the widespread use of therapeutics, including dexamethasone (DEXA). DEXA, a synthetic glucocorticoid, is among the widely administered drugs used to treat hospitalized COVID-19 patients. The global COVID-19 surge in infections, consequent increasing hospitalizations, and other DEXA applications have raised concerns on eminent adverse ecological implications to aquatic ecosystems. Here, we aim to summarize published studies on DEXA occurrence, fate, and effects on organisms in natural and engineered systems as, pre-COVID, the drug has been identified as an emerging environmental contaminant. The results demonstrated a significant reduction of DEXA in wastewater treatment plants, with a small portion, including its transformation products (TPs), being released into downstream waters. Fish and crustaceans are the most susceptible species to DEXA exposure in the parts-per-billion range, suggesting potential deleterious ecological effects. However, there are data deficits on the implications of DEXA to marine and estuarine systems and wildlife. To improve DEXA management, toxicological outcomes of DEXA and formed TPs should entail long-term studies from whole organisms to molecular effects in actual environmental matrices and at realistic exposure concentrations. This can aid in striking a fine balance of saving human lives and protecting ecological integrity.

Inhaled Edoxaban dry powder inhaler formulations: Development, characterization and their effects on the coagulopathy associated with COVID-19 infection

Herein, we demonstrated the development and characterization of a dry powder inhaler (DPI) formulation of edoxaban (EDX); and investigated the in-vitro anticoagulation effect for the management of pulmonary or cerebral coagulopathy associated with COVID-19 infection. The formulations were prepared by mixing the inhalable micronized drug with a large carrier lactose and dispersibility enhancers, leucine, and magnesium stearate. The drug-excipient interaction was studied using X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) methods. The drug and excipients showed no physical inter particulate interaction. The in-vitro drug aerosolization from the developed formulation was determined by a Twin Stage Impinger (TSI) at a flow rate of 60 ± 5 L /min. The amount of drug deposition was quantified by an established HPLC-UV method. The fine particle fraction (FPF) of EDX API from drug alone formulation was 7%, whereas the formulations with excipients increased dramatically to almost 7-folds up to 47%. The developed DPI formulation of EDX showed a promising in-vitro anticoagulation effect at a very low concentration. This novel DPI formulation of EDX could be a potential and effective inhalation therapy for managing pulmonary venous thromboembolism (VTE) associated with COVID-19 infection. Further studies are warranted to investigate the toxicity and clinical application of the inhaled EDX DPI formulation.

COVID-19-associated venous thromboembolism portends worse survival

Patients with coronavirus disease 2019 (COVID-19) seem to be at high risk for venous thromboembolism (VTE) development, but there is a paucity of data exploring both the natural history of COVID-19-associated VTE and the risk for poor outcomes after VTE development. This investigation aims to explore the relationship between COVID-19-associated VTE development and mortality. A prospectively maintained registry of patients older than 18 years admitted for COVID-19-related illnesses within an academic health care network between March and September 2020 was reviewed. Codes from the tenth revision of the International Classification of Diseases for VTE were collected. The charts of those patients with a code for VTE were manually reviewed to confirm VTE diagnosis. There were 2,552 patients admitted with COVID-19-related illnesses. One hundred and twenty-six patients (4.9%) developed a VTE. A disproportionate percentage of patients of Black race developed a VTE (70.9% VTE v 57.8% non-VTE; P = .012). A higher proportion of patients with VTE expired during their index hospitalization (22.8% VTE v 8.4% non-VTE; P < .001). On multivariable logistic regression analysis, VTE was independently associated with mortality (odds ratio = 3.17; 95% confidence interval, 1.9-5.2; P < .001). Hispanic/Latinx ethnicity was associated with decreased mortality (odds ratio = 0.45; 95% confidence interval, 0.21-1.00; P = .049). Hospitalized patients of Black race with COVID-19 were more prone to VTE development, and patients with COVID-19 who developed in-hospital VTE had roughly nearly threefold higher odds of mortality. Further emphasis should be placed on optimizing COVID-19 anticoagulation protocols to reduce mortality in this high-risk cohort.

Heparin and Its Derivatives: Challenges and Advances in Therapeutic Biomolecules

Heparin has been extensively studied as a safe medicine and biomolecule over the past few decades. Heparin derivatives, including low-molecular-weight heparins (LMWH) and heparin pentasaccharide, are effective anticoagulants currently used in clinical settings. They have also been studied as functional biomolecules or biomaterials for various therapeutic uses to treat diseases. Heparin, which has a similar molecular structure to heparan sulfate, can be used as a remarkable biomedicine due to its uniquely high safety and biocompatibility. In particular, it has recently drawn attention for use in drug-delivery systems, biomaterial-based tissue engineering, nanoformulations, and new drug-development systems through molecular formulas. A variety of new heparin-based biomolecules and conjugates have been developed in recent years and are currently being evaluated for use in clinical applications. This article reviews heparin derivatives recently studied in the field of drug development for the treatment of various diseases.

Follow-up after acute thrombotic events following COVID-19 infection

Objective

COVID-19 infection results in a hypercoagulable state predisposing patients to thrombotic events. We report the 3- and 6-month follow-up of 27 patients who experienced acute arterial thrombotic events in the setting of COVID-19 infection.

Methods

Data were prospectively collected and maintained for all vascular surgery consultations in the Mount Sinai Health System from patients who presented between March 16 and May 5, 2020.

Results

Twenty-seven patients experienced arterial thrombotic events. The average length of stay was 13.3 ± 15.4 days. Fourteen patients were treated with open surgical intervention, six were treated with endovascular intervention, and seven were treated with anticoagulation only. At 3-month follow-up, 11 patients (40.7%) were deceased. Nine patients who expired did so during the initial hospital stay. The 3-month cumulative primary patency rate for all interventions was 72.2%, and the 3-month primary patency rates for open surgical and endovascular interventions were 66.7 and 83.3, respectively. There were 9 (33.3%) readmissions within 3 months. Six-month follow-up was available in 25 (92.6%) patients. At 6-month follow-up, 12 (48.0%) patients were deceased, and the cumulative primary patency rate was 61.9%. The 6-month primary patency rates of open surgical and endovascular interventions were 66.7% and 55.6%, respectively. The limb-salvage rate at both 3 and 6 months was 89.2%.

Conclusions

Patients with COVID-19 infections who experienced thrombotic events saw high complication and mortality rates with relatively low patency rates.

The Platelet Role in Severe and Fatal Forms of COVID-19

On December 31, 2019, the World Health Organization received a report of several pneumonia cases in Wuhan, China. The causative agent was later confirmed as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Since then, the SARS-CoV-2 virus has spread throughout the world, giving rise in 2020 to the 2019 coronavirus (COVID-19) pandemic, which, according to the world map of the World Health Organization, has, until May 18, 2021, infected 163,312,429 people and caused 3,386,825 deaths throughout the world. Most critical patients progress rapidly to acute respiratory distress syndrome (ARDS) and, in underlying form, to septic shock, irreversible metabolic acidosis, blood coagulation dysfunction, or hemostatic and thrombotic anomalies have been reported as the leading causes of death due to COVID-19. The main findings in severe and fatal COVID-19 patients make it clear that platelets play a crucial role in developing severe disease cases. Platelets are the enucleated cells responsible for hemostasis and thrombi formation; thus, platelet hyperreactivity induced by pro-inflammatory microenvironments contributes to the "cytokine storm" that characterizes the more aggressive course of COVID- 19.

Long-chain polyphosphates impair SARS-CoV-2 infection and replication

Long-chain, inorganic polyphosphates (polyPs), which are found in many cells in the blood, have cytoprotective and antiviral activities, particularly against HIV-1 infection. Ferrucci et al. tested the effects of polyPs of various lengths on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. Molecular docking and binding analyses showed that polyPs bound to the host receptor ACE2, which facilitates viral entry, and a viral RNA polymerase required for replication. Both proteins underwent proteasomal degradation in cells incubated with polyP120, the optimal species tested, resulting in inhibition of SARS-CoV-2 replication and a reduced inflammatory response. Given that polyPs have low toxicity, these results suggest that their potential therapeutic use should be further explored.

Inorganic polyphosphates (polyPs) are linear polymers composed of repeated phosphate (PO₄³⁻) units linked together by multiple high-energy phosphoanhydride bonds. In addition to being a source of energy, polyPs have cytoprotective and antiviral activities. Here, we investigated the antiviral activities of long-chain polyPs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In molecular docking analyses, polyPs interacted with several conserved amino acid residues in angiotensin-converting enzyme 2 (ACE2), the host receptor that facilitates virus entry, and in viral RNA-dependent RNA polymerase (RdRp). ELISA and limited proteolysis assays using nano– LC-MS/MS mapped polyP120 binding to ACE2, and site-directed mutagenesis confirmed interactions between ACE2 and SARS-CoV-2 RdRp and identified the specific amino acid residues involved. PolyP120 enhanced the proteasomal degradation of both ACE2 and RdRp, thus impairing replication of the British B.1.1.7 SARS-CoV-2 variant. We thus tested polyPs for functional interactions with the virus in SARS-CoV-2–infected Vero E6 and Caco2 cells and in primary human nasal epithelial cells. Delivery of a nebulized form of polyP120 reduced the amounts of viral positive-sense genomic and subgenomic RNAs, of RNA transcripts encoding proinflammatory cytokines, and of viral structural proteins, thereby presenting SARS-CoV-2 infection in cells in vitro.

Prophylactic heparin and risk of orotracheal intubation or death in patients with mild or moderate COVID-19 pneumonia

Prophylactic low molecular weight heparin (pLMWH) is currently recommended in COVID-19 to reduce the risk of coagulopathy. The aim of this study was to evaluate whether the antinflammatory effects of pLMWH could translate in lower rate of clinical progression in patients with COVID-19 pneumonia. Patients admitted to a COVID-hospital in Rome with SARS-CoV-2 infection and mild/moderate pneumonia were retrospectively evaluated. The primary endpoint was the time from hospital admission to orotracheal intubation/death (OTI/death). A total of 449 patients were included: 39% female, median age 63 (IQR, 50–77) years. The estimated probability of OTI/death for patients receiving pLMWH was: 9.5% (95% CI 3.2–26.4) by day 20 in those not receiving pLMWH vs. 10.4% (6.7–15.9) in those exposed to pLMWH; p-value = 0.144. This risk associated with the use of pLMWH appeared to vary by PaO₂/FiO₂ ratio: aHR 1.40 (95% CI 0.51–3.79) for patients with an admission PaO₂/FiO₂ ≤ 300 mmHg and 0.27 (0.03–2.18) for those with PaO₂/FiO₂ > 300 mmHg; p-value at interaction test 0.16. pLMWH does not seem to reduce the risk of OTI/death mild/moderate COVID-19 pneumonia, especially when respiratory function had already significantly deteriorated. Data from clinical trials comparing the effect of prophylactic vs. therapeutic dosage of LMWH at various stages of COVID-19 disease are needed.

Management of therapeutic unfractionated heparin in COVID-19 patients: A retrospective cohort study

Background

Patients hospitalized with severe acute respiratory syndrome coronavirus 2 infection are at risk for thrombotic complications necessitating use of therapeutic unfractionated heparin (UFH). Full-dose anticoagulation limits requirements for organ support interventions in moderately ill patients with coronavirus disease 2019 (COVID-19). Given this benefit, it is important to evaluate response to therapeutic anticoagulation in this population.

Objectives

The aim of this study was to assess therapeutic UFH infusions and associated bleeding risk in patients with COVID-19.

Patients/Methods

This retrospective cohort study includes patients at Brigham and Women's Hospital, Boston, Massachusetts, receiving weight-based nursing-nomogram titrated UFH infusion during a 10-week surge in COVID-19 hospitalizations. Of 358 patients on therapeutic UFH during this interval, 97 (27.1%) had confirmed COVID-19. Patient characteristics, laboratory values, and information regarding UFH infusion and bleeding events were obtained from the electronic medical record.

Results

Patients who were COVID-19 positive had fewer therapeutic activatrd partial thromboplastin times (aPTTs) compared to COVID-19-negative patients (median rate, 40.0% vs 53.1%; P < .0005). Both major and clinically relevant nonmajor bleeding were increased in COVID-19-positive patients, with major bleeding observed in 10.3% (95% confidence interval [CI], 5.7%-17.9%) of patients who were COVID-19 positive and 3.1% (95% CI, 1.6%-5.9%) of patients who were COVID-19 negative (P < .005). In logistic regression, bleeding events were associated with receiving UFH for longer than 7 days, but not platelet count, coagulation, or inflammatory measurements.

Conclusions

Our data indicate a higher incidence of bleeding complications in patients with COVID-19 receiving weight-based nursing-nomogram titrated UFH infusions despite a higher prevalence of subtherapeutic aPTTs in this population. These data underscore the need for prospective studies aimed at improving the quality and safety of therapeutic anticoagulation in patients with COVID-19.

Therapeutic approaches for SARS-CoV-2 infection

Therapeutic approaches to COVID-19 treatment require appropriate inhibitors to target crucial proteins of SARS-CoV-2 replication machinery. It’s been approximately 12 months since the pandemic started, yet no known specific drugs are available. However, research progresses with time in terms of high throughput virtual screening (HTVS) and rational design of repurposed, novel synthetic and natural products discovery by understanding the viral life cycle, immuno-pathological and clinical outcomes in patients based on host’s nutritional, metabolic, and lifestyle status. Further, complementary and alternative medicine (CAM) approaches have also improved resiliency and immune responses. In this article, we summarize all the therapeutic antiviral strategies for COVID-19 drug discovery including computer aided virtual screening, repurposed drugs, immunomodulators, vaccines, plasma therapy, various adjunct therapies, and phage technology to unravel insightful mechanistic pathways of targeting SARS-CoV-2 and host’s intrinsic, innate immunity at multiple checkpoints that aid in the containment of the disease.

The Coronavirus Network Explorer: mining a large-scale knowledge graph for effects of SARS-CoV-2 on host cell function

BACKGROUND

Leveraging previously identified viral interactions with human host proteins, we apply a machine learning-based approach to connect SARS-CoV-2 viral proteins to relevant host biological functions, diseases, and pathways in a large-scale knowledge graph derived from the biomedical literature. Our goal is to explore how SARS-CoV-2 could interfere with various host cell functions, and to identify drug targets amongst the host genes that could potentially be modulated against COVID-19 by repurposing existing drugs. The machine learning model employed here involves gene embeddings that leverage causal gene expression signatures curated from literature. In contrast to other network-based approaches for drug repurposing, our approach explicitly takes the direction of effects into account, distinguishing between activation and inhibition.

RESULTS

We have constructed 70 networks connecting SARS-CoV-2 viral proteins to various biological functions, diseases, and pathways reflecting viral biology, clinical observations, and co-morbidities in the context of COVID-19. Results are presented in the form of interactive network visualizations through a web interface, the Coronavirus Network Explorer (CNE), that allows exploration of underlying experimental evidence. We find that existing drugs targeting genes in those networks are strongly enriched in the set of drugs that are already in clinical trials against COVID-19.

CONCLUSIONS

The approach presented here can identify biologically plausible hypotheses for COVID-19 pathogenesis, explicitly connected to the immunological, virological and pathological observations seen in SARS-CoV-2 infected patients. The discovery of repurposable drugs is driven by prior knowledge of relevant functional endpoints that reflect known viral biology or clinical observations, therefore suggesting potential mechanisms of action. We believe that the CNE offers relevant insights that go beyond more conventional network approaches, and can be a valuable tool for drug repurposing. The CNE is available at https://digitalinsights.qiagen.com/coronavirus-network-explorer .

Towards better understanding of the heparin role in NETosis: feasibility of using native mass spectrometry to monitor interactions of neutrophil elastase with heparin oligomers

Neutrophil elastase is a serine protease released by neutrophils, and its dysregulation has been associated with a variety of debilitating pathologies, most notably cystic fibrosis. This protein is also a prominent component of the so-called neutrophil extracellular traps (NETs), whose formation is a part of the innate immunity response to invading pathogens, but also contributes to a variety of pathologies ranging from autoimmune disorders and inflammation to cancer to thrombotic complications in COVID-19. Retention of neutrophil elastase within NETs is provided by ejected DNA chains, although this protein is also capable of interacting with a range of other endogenous polyanions, such as heparin and heparan sulfate. In this work, we evaluate the feasibility of using native mass spectrometry (MS) as a means of studying interactions of neutrophil elastase with heparin oligomers ranging from structurally homogeneous synthetic pentasaccharide fondaparinux to relatively long (up to twenty saccharide units) and structurally heterogeneous chains produced by partial depolymerization of heparin. The presence of heterogeneous glycan chains on neutrophil elastase and the structural heterogeneity of heparin oligomers render the use of standard MS to study their complexes impractical. However, supplementing MS with limited charge reduction in the gas phase allows meaningful data to be extracted from MS measurements. In contrast to earlier molecular modeling studies where a single heparin-binding site was identified, our work reveals the existence of multiple binding sites, with a single protein molecule being able to accommodate up to three decasaccharides. The measurements also reveal the ability of even relatively short heparin oligomers to bridge two protein molecules, suggesting that characterization of these complexes using native MS can shed light on the structural properties of NETs. Lastly, the use of MS allows the binding preferences of heparin oligomers to neutrophil elastase to be studied with respect to specific structural properties of heparin, such as the level of sulfation (i.e., charge density). All experimental measurements are carried out in parallel with molecular dynamics simulations of the protein/heparin oligomer systems, which are in remarkable agreement with the experimental data and highlight the role of electrostatic interactions as dominant forces governing the formation of these complexes.

A comprehensive guide to the pharmacologic regulation of angiotensin converting enzyme 2 (ACE2), the SARS-CoV-2 entry receptor

The recent emergence of coronavirus disease-2019 (COVID-19) as a global pandemic has prompted scientists to address an urgent need for defining mechanisms of disease pathology and treatment. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent for COVID-19, employs angiotensin converting enzyme 2 (ACE2) as its primary target for cell surface attachment and likely entry into the host cell. Thus, understanding factors that may regulate the expression and function of ACE2 in the healthy and diseased body is critical for clinical intervention. Over 66% of all adults in the United States are currently using a prescription drug and while earlier findings have focused on possible upregulation of ACE2 expression through the use of renin angiotensin system (RAS) inhibitors, mounting evidence suggests that various other widely administered drugs used in the treatment of hypertension, heart failure, diabetes mellitus, hyperlipidemias, coagulation disorders, and pulmonary disease may also present a varied risk for COVID-19. Specifically, we summarize mechanisms on how heparin, statins, steroids and phytochemicals, besides their established therapeutic effects, may also interfere with SARS-CoV-2 viral entry into cells. We also describe evidence on the effect of several vitamins, phytochemicals, and naturally occurring compounds on ACE2 expression and activity in various tissues and disease models. This comprehensive review aims to provide a timely compendium on the potential impact of commonly prescribed drugs and pharmacologically active compounds on COVID-19 pathology and risk through regulation of ACE2 and RAS signaling.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): a Systemic Infection

To date, seven identified coronaviruses (CoVs) have been found to infect humans; of these, three highly pathogenic variants have emerged in the 21st century. The newest member of this group, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first detected at the end of 2019 in Hubei province, China. Since then, this novel coronavirus has spread worldwide, causing a pandemic; the respiratory disease caused by the virus is called coronavirus disease 2019 (COVID-19). The clinical presentation ranges from asymptomatic to mild respiratory tract infections and influenza-like illness to severe disease with accompanying lung injury, multiorgan failure, and death. Although the lungs are believed to be the site at which SARS-CoV-2 replicates, infected patients often report other symptoms, suggesting the involvement of the gastrointestinal tract, heart, cardiovascular system, kidneys, and other organs; therefore, the following question arises: is COVID-19 a respiratory or systemic disease? This review aims to summarize existing data on the replication of SARS-CoV-2 in different tissues in both patients and ex vivo models.

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.

A rapid review of recent advances in diagnosis, treatment and vaccination for COVID-19

COVID-19 is caused by SARS-CoV-2, which originated in Wuhan, Hubei province, Central China, in December 2019 and since then has spread rapidly, resulting in a severe pandemic. The infected patient presents with varying non-specific symptoms requiring an accurate and rapid diagnostic tool to detect SARS-CoV-2. This is followed by effective patient isolation and early treatment initiation ranging from supportive therapy to specific drugs such as corticosteroids, antiviral agents, antibiotics, and the recently introduced convalescent plasma. The development of an efficient vaccine has been an on-going challenge by various nations and research companies. A literature search was conducted in early December 2020 in all the major databases such as Medline/PubMed, Web of Science, Scopus and Google Scholar search engines. The findings are discussed in three main thematic areas namely diagnostic approaches, therapeutic options, and potential vaccines in various phases of development. Therefore, an effective and economical vaccine remains the only retort to combat COVID-19 successfully to save millions of lives during this pandemic. However, there is a great scope for further research in discovering cost-effective and safer therapeutics, vaccines and strategies to ensure equitable access to COVID-19 prevention and treatment services.

SARS-CoV-2: Pathogenic Mechanisms and Host Immune Response

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an enveloped, positive-sense RNA coronavirus responsible for the COVID-19 pandemic. Since December 2019, coronavirus disease 2019 (COVID-19) has affected more than 127 million people, 2.7 million deaths globally (as per WHO dashboard, dated 31 March, 2020), the virus is capable of transmitting from human to human via inhalation of infected respiratory droplets or aerosols or contact with infected fomites. Clinically, patients with COVID-19 present with severe respiratory distress syndrome, which is very similar to the presentation of other respiratory viral infections. A huge variation in the host response exists, with the resulting symptoms varying from mild to moderate. Comorbidities such as cardiovascular disease, hypertension, diabetes, coagulation dysfunction, stroke, malignant tumor and multiple organ dysfunction syndrome, as well as age and sex, are associated with severe COVID-19 cases. So far, no targeted therapies have been developed to treat this disease and existing drugs are being investigated for repurposing. This chapter discusses the epidemiology, clinical features of COVID-19, pathogenesis and the innate and adaptive immune response mounted by the host to the SARS-CoV-2 infection. A deeper understanding of the host-pathogen interaction is fundamental to the development of a vaccine.

A 61-Year-Old Man with SARS-CoV-2 Infection and Venous Thrombosis Presenting with Painful Swelling and Gangrene of the Lower Limb Consistent with Phlegmasia Cerulea Dolens

Patient: Male, 61-year-old

Final Diagnosis: Phlegmasia cerulea dolens

Symptoms: Bilateral leg swelling • breathlessness • cough • fever

Medication: —

Clinical Procedure: —

Specialty: Cardiology • Infectious Diseases • Medicine, General and Internal

Systematic review and meta-analysis of the prevalence of venous thromboembolic events in novel coronavirus disease-2019 patients

Background

Emerging clinical evidence has shown that patients with the novel coronavirus disease-2019 (COVID-19) have complications that include venous thromboembolism (VTE), consisting of deep vein thrombosis (DVT) and pulmonary embolism (PE). The prevalence of VTE in patients hospitalized with COVID-19 is unclear.

Methods

Eligible studies on COVID-19 were collected from PubMed, Web of Science, and Embase. Patient characteristics and information were extracted for three categories of patients: consecutive, ICU, and non-ICU group. All PEs and DVTs were diagnosed by computed tomographic pulmonary arteriography and duplex ultrasound examination, respectively. A subgroup analysis of testing strategies in ICU and non-ICU patients for PE and DVT was also performed.

Results

Forty clinical studies involving 7966 patients hospitalized with COVID-19 were included. Pooled VTE prevalence was 13% in consecutive patients (95% confidence interval [CI], 0.05-0.24; I² = 97%), 7% in non-ICU patients (95% CI, 0.01-0.18; I² = 93%), and 31% in ICU patients (95% CI, 0.22-0.42; I² = 91%). ICU patients had the highest prevalence of PE among the three groups (17% [95% CI, 0.12-0.23] vs 8% in consecutive patients [95% CI, 0.04-0.13], 4% in non-ICU patients [95% CI, 0.01-0.08]). ICU patients also had the highest DVT prevalence (25% [95% CI, 0.14-0.37] vs 7% in consecutive patients [95% CI, 0.03-0.14], and 7% in non-ICU [95% CI, 0.02-0.14]). The subgroup analysis showed a three-fold improvement in the PE and DVT detection rates in both ICU and non-ICU patients with COVID-19 when the screening test for VTE was applied. In the settings of screening tests for VTE, ICU patients have a significantly higher prevalence of PE (37% vs 10%; P < .0001) and DVT (40% vs 12%; P = .0065) compared with non-ICU patients.

Conclusions

VTE is common in patients hospitalized with COVID-19, especially among ICU patients. Screening tests for PE and DVT may significantly improve detection rates in both ICU and non-ICU patients with COVID-19 than tests based on clinical suspicion.

Covid-19-Associated Coagulopathy: Biomarkers of Thrombin Generation and Fibrinolysis Leading the Outcome

Background: Coronavirus Disease 2019 (COVID-19)-associated coagulopathy is characterized by a prothrombotic state not yet comprehensively studied. We investigated the coagulation pattern of patients with COVID-19 acute respiratory distress syndrome (ARDS), comparing patients who survived to those who did not. Methods: In this prospective cohort study on 20 COVID-19 ARDS patients, the following biomarkers were measured: thrombin generation (prothrombin fragment 1 + 2 (PF 1 + 2)), fibrinolysis activation (tissue plasminogen activator (tPA)) and inhibition (plasminogen activator inhibitor 2 (PAI-2)), fibrin synthesis (fibrinopeptide A) and fibrinolysis magnitude (plasmin–antiplasmin complex (PAP) and D-dimers). Measurements were done upon intensive care unit (ICU) admission and after 10–14 days. Results: There was increased thrombin generation; modest or null release of t-PA; and increased levels of PAI-2, fibrinopeptide A, PAP and D-dimers. At baseline, nonsurvivors had a significantly (p = 0.014) higher PAI-2/PAP ratio than survivors (109, interquartile range (IQR) 18.1–216, vs. 8.7, IQR 2.9–12.6). At follow-up, thrombin generation was significantly (p = 0.025) reduced in survivors (PF 1 + 2 from 396 pg/mL, IQR 185–585 to 237 pg/mL, IQR 120–393), whereas it increased in nonsurvivors. Fibrinolysis inhibition at follow-up remained stable in survivors and increased in nonsurvivors, leading to a significant (p = 0.026) difference in PAI-2 levels (161 pg/mL, IQR 50–334, vs. 1088 pg/mL, IQR 177–1565). Conclusion: Severe patterns of COVID-19 ARDS are characterized by a thrombin burst and the consequent coagulation activation. Mechanisms of fibrinolysis regulation appear unbalanced toward fibrinolysis inhibition. This pattern ameliorates in survivors, whereas it worsens in nonsurvivors.

The vascular side of COVID-19 disease. Position paper of the International Union of Angiology

The SARS-CoV-2 infection (COVID-19) is causing an ongoing pandemic and potentially fatal disease. Development of coagulopathy with thrombotic complications such as deep vein thrombosis and pulmonary embolism are emerging as factors for progression to severe disease and death. Also, a markedly increased level of D-dimer, a protein product of fibrin degradation, has been associated to mortality. Furthermore, activation of immune response due to virus infection may led to uncontrolled severe inflammation with damage to host cells and induction of endotheliitis and cellular apoptosis and pyroptosis. The use of low molecular weight heparin in early stage of the disease could prevent vascular complications and reduce the progression to severe stage of the disease. Aim of this paper was to summarize current evidence about vascular involvement in COVID-19 disease and potential antithrombotic therapy.