Potential Therapeutic Roles for Direct Factor Xa Inhibitors in Coronavirus Infections.

Human factor Xa (FXa) is a serine protease of the common coagulation pathway. FXa is known to activate prothrombin to thrombin, which eventually leads to the formation of cross-linked blood clots. While this process is important in maintaining hemostasis, excessive thrombin generation results in a host of thrombotic conditions. FXa has also been linked to inflammation via protease-activated receptors. Together, coagulopathy and inflammation have been implicated in the pathogenesis of viral infections, including the current coronavirus pandemic. Direct FXa inhibitors have been shown to possess anti-inflammatory and antiviral effects, in addition to their established anticoagulant activity. This review summarizes the pharmacological activities of direct FXa inhibitors, their pharmacokinetics, potential drug-drug interactions and adverse effects, and the details of clinical trials involving direct FXa inhibitors in coronavirus disease 2019 (COVID-19) patients.

Prognostic Value of Antithrombin Levels in COVID-19 Patients and Impact of Fresh Frozen Plasma Treatment: A Retrospective Study

Objective: The defective interplay between coagulation and inflammation may be the leading cause of intravascular coagulation and organ dysfunction in coronavirus disease-19 (COVID-19) patients. Abnormal coagulation profiles were reported to be associated with poor outcomes. In this study, we assessed the prognostic values of antithrombin (AT) activity levels and the impact of fresh frozen plasma (FFP) treatment on outcome. Materials and Methods: Conventional coagulation parameters as well as AT activity levels and outcomes of 104 consecutive critically ill acute respiratory distress syndrome (ARDS) patients with laboratory-confirmed COVID-19 disease were retrospectively analyzed. Patients with AT activity below 75% were treated with FFP. Maximum AT activity levels achieved in those patients were recorded. Results: AT activity levels at admission were significantly lower in nonsurvivors than survivors (73% vs. 81%). The cutoff level for admission AT activity was 79% and 58% was the lowest AT for survival. The outcome in those patients who had AT activity levels above 75% after FFP treatment was better than that of the nonresponding group. As well as AT, admission values of D-dimer, C-reactive protein, and procalcitonin were coagulation and inflammatory parameters among the mortality risk factors. Conclusion: AT activity could be used as a prognostic marker for survival and organ failure in COVID-19-associated ARDS patients. AT supplementation therapy with FFP in patients with COVID-19-induced hypercoagulopathy may improve thrombosis prophylaxis and thus have an impact on survival.

Mesenchymal stromal cells to fight SARS-CoV-2: Taking advantage of a pleiotropic therapy.

The devastating global impact of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has prompted scientists to develop novel strategies to fight Coronavirus Disease of 2019 (COVID-19), including the examination of pre-existing treatments for other viral infections in COVID-19 patients. This review provides a reasoned discussion of the possible use of Mesenchymal Stromal Cells (MSC) or their products as a treatment in SARS-CoV-2-infected patients. The main benefits and concerns of using this cellular therapy, guided by preclinical and clinical data obtained from similar pathologies will be reviewed. MSC represent a highly immunomodulatory cell population and their use may be safe according to clinical studies developed in other pathologies. Notably, four clinical trials and four case reports that have already been performed in COVID-19 patients obtained promising results. The clinical application of MSC in COVID-19 is very preliminary and further investigational studies are required to determine the efficacy of the MSC therapy. Nevertheless, these preliminary studies were important to understand the therapeutic potential of MSC in COVID-19. Based on these encouraging results, the United States Food and Drug Administration (FDA) authorized the compassionate use of MSC, but only in patients with Acute Respiratory Distress Syndrome (ARDS) and a poor prognosis. In fact, patients with severe SARS-CoV-2 can present infection and tissue damage in different organs, such as lung, heart, liver, kidney, gut and brain, affecting their function. MSC may have pleiotropic activities in COVID-19, with the capacity to fight inflammation and repair lesions in several organs.

Long-acting nanoparticulate DNase-1 for effective suppression of SARS-CoV-2-mediated neutrophil activities and cytokine storm.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new strain of coronavirus not previously identified in humans. Globally, the number of confirmed cases and mortality rates of coronavirus disease 2019 (COVID-19) have risen dramatically. Currently, there are no FDA-approved antiviral drugs and there is an urgency to develop treatment strategies that can effectively suppress SARS-CoV-2-mediated cytokine storms, acute respiratory distress syndrome (ARDS), and sepsis. As symptoms progress in patients with SARS-CoV-2 sepsis, elevated amounts of cell-free DNA (cfDNA) are produced, which in turn induce multiple organ failure in these patients. Furthermore, plasma levels of DNase-1 are markedly reduced in SARS-CoV-2 sepsis patients. In this study, we generated recombinant DNase-1-coated polydopamine-poly(ethylene glycol) nanoparticulates (named long-acting DNase-1), and hypothesized that exogenous administration of long-acting DNase-1 may suppress SARS-CoV-2-mediated neutrophil activities and the cytokine storm. Our findings suggest that exogenously administered long-acting nanoparticulate DNase-1 can effectively reduce cfDNA levels and neutrophil activities and may be used as a potential therapeutic intervention for life-threatening SARS-CoV-2-mediated illnesses.

Tocilizumab use in patients with moderate to severe COVID-19: A retrospective cohort study.

WHAT IS KNOWN AND OBJECTIVE: The coronavirus disease 2019 (COVID-19) associated cytokine activation can lead to a rapid progression into respiratory failure, shock and multiorgan failure. Interleukin-6 (IL-6) is a pro-inflammatory cytokine that likely contributes to the pathogenesis of cytokine release syndrome. It is hypothesized that modulating IL-6 levels or its effects with tocilizumab, a recombinant humanized anti-IL-6 receptor monoclonal antibody, may alter the course of disease. METHODS: We examined the association between tocilizumab use and intubation or death at a community hospital in New York City. Data were obtained regarding consecutive patients hospitalized with COVID-19. The primary end point was a composite of intubation or death in a time-to-event analysis. We compared outcomes in patients who received tocilizumab with those in patients who did not, using a multivariable Cox model with inverse probability weighting according to the propensity score. RESULTS AND DISCUSSION: In this single-centre retrospective cohort study involving 1225 hospitalized patients with SARS-CoV-2 infection, the probability to respiratory failure, which was measured as intubation or death, was less frequent in patients who received tocilizumab. WHAT IS NEW AND CONCLUSION: Tocilizumab and other IL-6 receptor monoclonal antibodies may evolve as a viable option in treating patients with moderate and severe COVID-19.

A novel role of nifuroxazide in attenuation of sepsis-associated acute lung and myocardial injuries; role of TLR4/NLPR3/IL-1ß signaling interruption.

Acute lung injury (ALI) and the subsequent multi-system organ failure is a serious health problem with devastating impacts on the health care systems. Indeed, the world has been facing an un-preceded situation in the past couple of months following COVID-19 infestation and the associated high-mortality rates mainly attributed to sepsis and the associated multiple organ failures of particular concern; acute respiratory distress syndrome post lung injury. The current study provides evidence on the ameliorative impact of nifuroxazide, and FDA approved antidiarrheal drug in attenuation of lipopolysaccharide (LPS)-induced ALI and myocarditis when administrated either in prophylactic or curative regimens. Nifuroxazide administration was associated with a significant improvement in lung and heart histopathological characteristics and architecture with retraction of LPS-induced inflammatory-infiltration. This was associated with retraction in serum biomarkers of cellular injury of which; LDH, CK-MB, and ALP. Nifuroxazide administration was associated with a significant improvement in both lung and heart oxidative status. Such positive outcomes were underlined by a significant inhibitory effect of nifuroxazide on lung and heart contents of toll-like receptor (4) (TLR4)/the inflammasome NALPR3/interleukin- 1ß (IL-1ß). In conclusion: Nifuroxazide attenuates LPS-induced ALI and myocardial injury via interruption of TLR4/NALPR3/IL-1ß signaling. Thus it can offer a potential approach for attenuation of sepsis in critically ill patients.

Mesenchymal stem cell therapy for acute respiratory distress syndrome: from basic to clinics.

The 2019 novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has occurred in China and around the world. SARS-CoV-2-infected patients with severe pneumonia rapidly develop acute respiratory distress syndrome (ARDS) and die of multiple organ failure. Despite advances in supportive care approaches, ARDS is still associated with high mortality and morbidity. Mesenchymal stem cell (MSC)-based therapy may be an potential alternative strategy for treating ARDS by targeting the various pathophysiological events of ARDS. By releasing a variety of paracrine factors and extracellular vesicles, MSC can exert anti-inflammatory, anti-apoptotic, anti-microbial, and pro-angiogenic effects, promote bacterial and alveolar fluid clearance, disrupt the pulmonary endothelial and epithelial cell damage, eventually avoiding the lung and distal organ injuries to rescue patients with ARDS. An increasing number of experimental animal studies and early clinical studies verify the safety and efficacy of MSC therapy in ARDS. Since low cell engraftment and survival in lung limit MSC therapeutic potentials, several strategies have been developed to enhance their engraftment in the lung and their intrinsic, therapeutic properties. Here, we provide a comprehensive review of the mechanisms and optimization of MSC therapy in ARDS and highlighted the potentials and possible barriers of MSC therapy for COVID-19 patients with ARDS.

The cytokine storm of COVID-19: a spotlight on prevention and protection.

INTRODUCTION: The cytokine release syndrome (CRS) of COVID-19 is associated with the development of critical illness requiring multi-organ support. Further research is required to halt progression of multi-organ injury induced by hyper-inflammation. AREAS COVERED: PubMed/MEDLINETM databases were accessed between May 9th-June 9th, 2020, to review the latest perspectives on the treatment and pathogenesis of CRS. EXPERT OPINION: Over-activity of chemotaxis triggers a macrophage activation syndrome (MAS) resulting in the release of pro-inflammatory cytokines. IL-6 and TNF- α are at the forefront of hyper-inflammation. The inflammatory cascade induces endothelial activation and capillary leak, leading to circulatory collapse and shock. As endothelial dysfunction persists, there is activation of the clotting cascade and microvascular obstruction. Continued endothelial activation results in multi-organ failure, regardless of pulmonary tissue damage. We propose that targeting the endothelium may interrupt this cycle. Immuno-modulating therapies have been suggested, however, further data is necessary to confirm that they do not jeopardize adaptive immunity. Inhibition of IL-6 and the Janus Kinase, signal transducer and activator of transcription proteins pathway (JAK/STAT), are favorable targets. Remote ischemic conditioning (RIC) reduces the inflammation of sepsis in animal models and should be considered as a low risk intervention, in combination with cardiovascular protection.