Hyperinflammation and derangement of renin-angiotensin-aldosterone system in COVID-19: A novel hypothesis for clinically suspected hypercoagulopathy and microvascular immunothrombosis

COVID-19, coagulopathy and venous thromboembolism: more questions than answers

The acute respiratory illnesses caused by severe acquired respiratory syndrome corona Virus-2 (SARS-CoV-2) is a global health emergency, involving more than 8.6 million people worldwide with more than 450,000 deaths. Among the clinical manifestations of COVID-19, the disease that results from SARS-CoV-2 infection in humans, a prominent feature is a pro-thrombotic derangement of the hemostatic system, possibly representing a peculiar clinicopathologic manifestation of viral sepsis. The severity of the derangement of coagulation parameters in COVID-19 patients has been associated with a poor prognosis, and the use of low molecular weight heparin (LMWH) at doses registered for prevention of venous thromboembolism (VTE) has been endorsed by the World Health Organization and by Several Scientific societies. However, some relevant issues on the relationships between COVID-19, coagulopathy and VTE have yet to be fully elucidated. This review is particularly focused on four clinical questions: What is the incidence of VTE in COVID-19 patients? How do we frame the COVID-19 associated coagulopathy? Which role, if any, do antiphospolipid antibodies have? How do we tackle COVID-19 coagulopathy? In the complex scenario of an overwhelming pandemic, most everyday clinical decisions have to be taken without delay, although not yet supported by a sound scientific evidence. This review discusses the most recent findings of basic and clinical research about the COVID-associated coagulopathy, to foster a more thorough knowledge of the mechanisms underlying this compelling disease.

Early Brain Imaging Shows Increased Severity of Acute Ischemic Strokes With Large Vessel Occlusion in COVID-19 Patients

BACKGROUND AND PURPOSE

Reports are emerging regarding the association of acute ischemic strokes with large vessel occlusion and coronavirus disease 2019 (COVID-19). While a higher severity of these patients could be expected from the addition of both respiratory and neurological injury, COVID-19 patients with strokes can present with mild or none respiratory symptoms. We aimed to compare anterior circulation large vessel occlusion strokes severity between patients with and without COVID-19.

METHODS

We performed a comparative cohort study between patients with COVID-19 who had anterior circulation large vessel occlusion and early brain imaging within 3 hours from onset, in our institution during the 6 first weeks of the COVID-19 outbreak and a control group admitted during the same calendar period in 2019.

RESULTS

Twelve COVID-19 patients with anterior circulation large vessel occlusion and early brain imaging were included during the study period and compared with 34 control patients with anterior circulation large vessel occlusion and early brain imaging in 2019. Patients in the COVID-19 group were younger (P=0.032) and had a history of diabetes mellitus more frequently (P=0.039). Patients did not significantly differ on initial National Institutes of Health Stroke Scale nor time from onset to imaging (P=0.18 and P=0.6, respectively). Patients with COVID-19 had more severe strokes than patients without COVID-19, with a significantly lower clot burden score (median: 6.5 versus 8, P=0.016), higher rate of multivessel occlusion (50% versus 8.8%, P=0.005), lower DWI-ASPECTS (Diffusion-Weighted Imaging-Alberta Stroke Program Early CT Scores; median: 5 versus 8, P=0.006), and higher infarct core volume (median: 58 versus 6 mL, P=0.004). Successful recanalization rate was similar in both groups (P=0.767). In-hospital mortality was higher in the COVID-19 patients' group (41.7% versus 11.8%, P=0.025).

CONCLUSIONS

Early brain imaging showed higher severity large vessel occlusion strokes in patients with COVID-19. Given the massive number of infected patients, concerns should be raised about the coming neurovascular impact of the pandemic worldwide.

A meta-analysis of the incidence of venous thromboembolic events and impact of anticoagulation on mortality in patients with COVID-19

BACKGROUND

The incidence of venous thromboembolic events (VTE) in patients with COVID-19 is generally high but varies markedly. However, the relationship between anticoagulation and mortality in patients with COVID-19 is still unclear.

METHODS

We performed a systematic review and meta-analysis to determine the incidence of VTE and evaluate the role of anticoagulation in patients with COVID-19. Random effects models were used to determine overall pooled estimates and 95% confidence intervals (CIs).

RESULTS

After a database search, 25 observational studies (20 on VTE incidence and 5 on the relationship between anticoagulation and mortality) were included. The pooled incidence rates of VTE, pulmonary embolism (PE), and deep vein thrombosis (DVT) in hospitalised COVID-19 patients were 21% (95% CI 15-27%), 15% (95% CI 10-20%), and 27% (95% CI 19-36%), respectively. A meta-analysis of five studies found that anticoagulation was not associated with an increased risk of mortality in hospitalised COVID-19 patients (RR = 0.86, 95% CI, 0.69-1.09, P = 0.218; I2 = 47.4%).

CONCLUSIONS

In conclusion, the incidence of VTE among hospitalised COVID-19 patients was high. Clinical trials are urgently needed to evaluate the roles of prophylactic and therapeutic anticoagulation in COVID-19.

COVID-19 vaccine-readiness for anti-CD20-depleting therapy in autoimmune diseases

Although most autoimmune diseases are considered to be CD4 T cell- or antibody-mediated, many respond to CD20-depleting antibodies that have limited influence on CD4 and plasma cells. This includes rituximab, oblinutuzumab and ofatumumab that are used in cancer, rheumatoid arthritis and off-label in a large number of other autoimmunities and ocrelizumab in multiple sclerosis. Recently, the COVID-19 pandemic created concerns about immunosuppression in autoimmunity, leading to cessation or a delay in immunotherapy treatments. However, based on the known and emerging biology of autoimmunity and COVID-19, it was hypothesised that while B cell depletion should not necessarily expose people to severe SARS-CoV-2-related issues, it may inhibit protective immunity following infection and vaccination. As such, drug-induced B cell subset inhibition, that controls at least some autoimmunities, would not influence innate and CD8 T cell responses, which are central to SARS-CoV-2 elimination, nor the hypercoagulation and innate inflammation causing severe morbidity. This is supported clinically, as the majority of SARS-CoV-2-infected, CD20-depleted people with autoimmunity have recovered. However, protective neutralizing antibody and vaccination responses are predicted to be blunted until naive B cells repopulate, based on B cell repopulation kinetics and vaccination responses, from published rituximab and unpublished ocrelizumab (NCT00676715, NCT02545868) trial data, shown here. This suggests that it may be possible to undertake dose interruption to maintain inflammatory disease control, while allowing effective vaccination against SARS-CoV-29, if and when an effective vaccine is available.

Systems Biology Approaches for Therapeutics Development Against COVID-19

Understanding the systems biology approaches for promoting the development of new therapeutic drugs is attaining importance nowadays. The threat of COVID-19 outbreak needs to be vanished for global welfare, and every section of research is focusing on it. There is an opportunity for finding new, quick, and accurate tools for developing treatment options, including the vaccine against COVID-19. The review at this moment covers various aspects of pathogenesis and host factors for exploring the virus target and developing suitable therapeutic solutions through systems biology tools. Furthermore, this review also covers the extensive details of multiomics tools i.e., transcriptomics, proteomics, genomics, lipidomics, immunomics, and in silico computational modeling aiming towards the study of host-virus interactions in search of therapeutic targets against the COVID-19.

Bilateral Popliteal Vein Thrombosis, Acute Pulmonary Embolism and Mild COVID-19

In 2020, the coronavirus disease 2019 (COVID-19) has become a global health disaster. Patients with COVID-19 have variable clinical features and unpredictable prognoses; the infectious complication may occur in many organs, causing a broad spectrum of symptoms and severity. Pulmonary embolism (PE) is a fatal urgent complication, which may occur following a severe infection. While the pathogenesis of PE in COVID-19 remains uncertain, it has mainly occurred in patients with severe disease. PE, as an initial presentation of COVID-19 in a patient with mild diseases, is rare and understudied. Here, we describe a young woman with mild COVID-19 illness and no significant risk factors for PE, except obesity, but had developed bilateral popliteal vein thrombosis and submassive PE. Our case emphasizes that thrombotic complications can occur in any COVID-19 patients regardless of the disease severity, questioning the role of preventive anticoagulants in mild COVID-19 cases with certain risk factors. 

Vascular Manifestations of COVID-19 - Thromboembolism and Microvascular Dysfunction

The coronavirus pandemic has reportedly infected over 31.5 million individuals and caused over 970,000 deaths worldwide (as of 22nd Sept 2020). This novel coronavirus, officially named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), although primarily causes significant respiratory distress, can have significant deleterious effects on the cardiovascular system. Severe cases of the virus frequently result in respiratory distress requiring mechanical ventilation, often seen, but not confined to, individuals with pre-existing hypertension and cardiovascular disease, potentially due to the fact that the virus can enter the circulation via the lung alveoli. Here the virus can directly infect vascular tissues, via TMPRSS2 spike glycoprotein priming, thereby facilitating ACE-2-mediated viral entry. Clinical manifestations, such as vasculitis, have been detected in a number of vascular beds (e.g., lungs, heart, and kidneys), with thromboembolism being observed in patients suffering from severe coronavirus disease (COVID-19), suggesting the virus perturbs the vasculature, leading to vascular dysfunction. Activation of endothelial cells via the immune-mediated inflammatory response and viral infection of either endothelial cells or cells involved in endothelial homeostasis, are some of the multifaceted mechanisms potentially involved in the pathogenesis of vascular dysfunction within COVID-19 patients. In this review, we examine the evidence of vascular manifestations of SARS-CoV-2, the potential mechanism(s) of entry into vascular tissue and the contribution of endothelial cell dysfunction and cellular crosstalk in this vascular tropism of SARS-CoV-2. Moreover, we discuss the current evidence on hypercoagulability and how it relates to increased microvascular thromboembolic complications in COVID-19.

Vascular Manifestations of COVID-19 - Thromboembolism and Microvascular Dysfunction

The coronavirus pandemic has reportedly infected over 31.5 million individuals and caused over 970,000 deaths worldwide (as of 22nd Sept 2020). This novel coronavirus, officially named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), although primarily causes significant respiratory distress, can have significant deleterious effects on the cardiovascular system. Severe cases of the virus frequently result in respiratory distress requiring mechanical ventilation, often seen, but not confined to, individuals with pre-existing hypertension and cardiovascular disease, potentially due to the fact that the virus can enter the circulation via the lung alveoli. Here the virus can directly infect vascular tissues, via TMPRSS2 spike glycoprotein priming, thereby facilitating ACE-2-mediated viral entry. Clinical manifestations, such as vasculitis, have been detected in a number of vascular beds (e.g., lungs, heart, and kidneys), with thromboembolism being observed in patients suffering from severe coronavirus disease (COVID-19), suggesting the virus perturbs the vasculature, leading to vascular dysfunction. Activation of endothelial cells via the immune-mediated inflammatory response and viral infection of either endothelial cells or cells involved in endothelial homeostasis, are some of the multifaceted mechanisms potentially involved in the pathogenesis of vascular dysfunction within COVID-19 patients. In this review, we examine the evidence of vascular manifestations of SARS-CoV-2, the potential mechanism(s) of entry into vascular tissue and the contribution of endothelial cell dysfunction and cellular crosstalk in this vascular tropism of SARS-CoV-2. Moreover, we discuss the current evidence on hypercoagulability and how it relates to increased microvascular thromboembolic complications in COVID-19.

COVID-19 and Major Organ Thromboembolism: Manifestations in Neurovascular and Cardiovascular Systems

COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been shown to cause multisystemic damage. We undertook a systematic literature review and comprehensive analysis of a total of 55 articles on arterial and venous thromboembolism in COVID-19 and articles on previous pandemics with respect to thromboembolism and compared the similarities and differences between them. The presence of thrombosis in multiple organ systems points to thromboembolism being an integral component in the pathogenesis of this disease. Thromboembolism is likely to be the main player in the morbidity and mortality of COVID -19 in which the pulmonary system is most severely affected. We also hypothesize that D-dimer values could be used as an early marker for prognostication of disease as it has been seen to be raised even in the pre-symptomatic stage. This further strengthens the notion that thromboembolism prevention is necessary. We also examined literature on the neurovascular and cardiovascular systems, as the manifestation of thromboembolic phenomenon in these two systems varied, suggesting different pathophysiology of damage. Further research into the role of thromboembolism in COVID-19 is important to advance the understanding of the virus, its effects and to tailor treatment accordingly to prevent further casualties from this pandemic.

COVID-19-Induced Neurovascular Injury: a Case Series with Emphasis on Pathophysiological Mechanisms

Coronavirus disease 2019 (COVID-19) is associated with a high inflammatory burden that can induce severe respiratory disease among other complications; vascular and neurological damage has emerged as a key threat to COVID-19 patients. Risk of severe infection and mortality increases with age, male sex, and comorbidities including cardiovascular disease, hypertension, obesity, diabetes, and chronic pulmonary disease. We review clinical and neuroradiological findings in five patients with COVID-19 who suffered severe neurological disease and illustrate the pathological findings in a 7-year-old boy with COVID-19-induced encephalopathy whose brain tissue sample showed angiocentric mixed mononuclear inflammatory infiltrate. We summarize the structural and functional properties of the virus including the molecular processes that govern the binding to its membrane receptors and cellular entry. In addition, we review clinical and experimental evidence in patients and animal models that suggests coronaviruses enter into the central nervous system (CNS), either via the olfactory bulb or through hematogenous spread. We discuss suspected pathophysiological mechanisms including direct cellular infection and associated recruitment of immune cells and neurovirulence, at least in part, mediated by cytokine secretion. Moreover, contributing to the vascular and neurological injury, coagulopathic disorders play an important pathogenic role. We survey the molecular events that contribute to the thrombotic microangiopathy. We describe the neurological complications associated with COVID-19 with a focus on the potential mechanisms of neurovascular injury. Our thesis is that following infection, three main pathophysiological processes-inflammation, thrombosis, and vascular injury-are responsible for the neurological damage and diverse pathology seen in COVID-19 patients.

From COVID-19 to clot: the involvement of the complement system

In December 2019, the world observed an unexpected outbreak of an emerging disease named coronavirus (COVID-19) that was first reported in Wuhan city of Hubei province of China. Recent literature has shown the association between COVID-19 infection and derangement in the coagulation profile. In this paper, we are discussing thrombo-genesis, especially the role of the complement system in the immune response against COVID-19 and the pathogenesis associated with tissue inflammation and thrombosis. This role can stipulate a groundwork for further investigation of the pathophysiologic importance of complement in COVID-19, and could propose targets for specific intervention. In addition, we delineated current treatments for thrombosis and the potential therapies by using agents to block the terminal complement pathway. Low molecular weight heparin for all (unless contraindicated) hospitalized COVID-19 patients can be lifesaving. Agents that inhibit the terminal events of the complement cascade might be crucial for ensuring an efficient treatment, decrease clots and permit early discharge in relation to COVID-19.Communicated by Ramaswamy H. Sarma.

Coagulopathy associated with COVID-19 - Perspectives & Preventive strategies using a biological response modifier Glucan

Direct endothelial injury by viruses and dysregulation of clotting mechanisms due to cytokine storm are the major precipitating factors of mortality in COVID-19; both are attributed to a fundamental dysregulation of the immune system. While immune dysregulation can be attributed to several factors, the risk of associated thrombogenic disruption varies across individuals. This variation depends on several factors, such as comorbidities, including diabetes, hypertension, and cardiovascular diseases. When considering ethnic variations, the vulnerability of Caucasians, African Americans and Hispanics needs to be addressed before arriving at strategies to handle thromboembolic complications, which have been identified in recent reports as the leading causes of mortality in COVID-19. Although evaluation of D-dimer and prothrombin during admission is considered to predict prognosis and mortality, there are no preventive or prophylactic strategies before hospital admission. Herein, we present our perspectives on the effect of regular supplementation with the biological response modifier beta glucan based on its relevance to immune modulation. This effect is of paramount importance in decreasing the development of severe COVID-19 and reducing mortality against the background of coagulopathy, especially in vulnerable populations.

Approaching coronavirus disease 2019: Mechanisms of action of repurposed drugs with potential activity against SARS-CoV-2

On March 11, 2020, the World Health Organization (WHO) declared the severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2) a global pandemic. As of July 2020, SARS-CoV-2 has infected more than 14 million people and provoked more than 590,000 deaths, worldwide. From the beginning, a variety of pharmacological treatments has been empirically used to cope with the life-threatening complications associated with Corona Virus Disease 2019 (COVID-19). Thus far, only a couple of them and not consistently across reports have been shown to further decrease mortality, respect to what can be achieved with supportive care. In most cases, and due to the urgency imposed by the number and severity of the patients' clinical conditions, the choice of treatment has been limited to repurposed drugs, approved for other indications, or investigational agents used for other viral infections often rendered available on a compassionate-use basis. The rationale for drug selection was mainly, though not exclusively, based either i) on the activity against other coronaviruses or RNA viruses in order to potentially hamper viral entry and replication in the epithelial cells of the airways, and/or ii) on the ability to modulate the excessive inflammatory reaction deriving from dysregulated host immune responses against the SARS-CoV-2. In several months, an exceptionally large number of clinical trials have been designed to evaluate the safety and efficacy of anti-COVID-19 therapies in different clinical settings (treatment or pre- and post-exposure prophylaxis) and levels of disease severity, but only few of them have been completed so far. This review focuses on the molecular mechanisms of action that have provided the scientific rationale for the empirical use and evaluation in clinical trials of structurally different and often functionally unrelated drugs during the SARS-CoV-2 pandemic.

Rate of venous thromboembolism in a prospective all-comers cohort with COVID-19

COVID-19 is associated with a variety of clinical complications including coagulopathy, which frequently results in venous thromboembolism (VTE). Retrospective analyses reported a markedly increased rate of VTEs in COVID-19. However, most recent studies on coagulopathy in COVID-19 were only focused on critically ill patients, and without suitable control groups. We aimed to evaluate the rate of VTEs in an all-comers cohort with suspected COVID-19 during a 30-days follow-up period. We also studied the level of D-dimers and their association with the course of disease. In our prospective single-center study (DRKS00021206, 03/30/2020), we analyzed 190 patients with suspected COVID-19 admitted to the emergency department between March and April 2020. Forty-nine patients were SARS-CoV-2 positive (25.8%). The 141 SARS-CoV-2-negative patients served as control group. After completion of a 30-days follow-up, VTE was diagnosed in 3 patients of the SARS-CoV-2-positive group (6.1%, amongst these 2 ICU cases) versus 5 patients in the SARS-CoV-2-negative group (3.5%), however the difference was not statistically significant (p = 0.427). 30-days mortality was similar in both groups (6.1% vs. 5%, p = 0.720). Disease severity correlated with the maximum level of D-dimers during follow-up in COVID-19. The rate of VTE was numerically higher in SARS-CoV-2 positive all-comers presenting with suspected COVID-19 as compared to well-matched controls suffering from similar symptoms. VTEs in the COVID-19 group predominantly occurred in ICU courses. The maximum level of D-dimers during follow-up was associated with disease severity in COVID-19, whereas the level of D-dimers at admission was not.

The morbidity and mortality of COVID-19 are correlated with the Ile105Val glutathione S-transferase P1 polymorphism

Background

Oxidative stress is an important issue in coronavirus disease 2019 (COVID-19). Considering that glutathione S-transferase P1 (GSTP1) is involved in cellular detoxification, it may play an important role in susceptibility to infection with SARS-CoV-2 and/or its outcome. In the present study, the association between the Ile105Val GSTP1 polymorphism (rs1695) and susceptibility to SARS-CoV-2 infection, as well as its outcome was investigated. Data on the prevalence (per 106 people), case-fatality (per 100 infected cases), and mortality (per 106 people) of COVID-19 and various potential confounders (the life expectancy at birth, density of medical doctors, density of nursing and midwifery personnel, and the gross national income per capita) were used. The latest data available for 45 countries were used for the study.

Results

In multivariate linear regression analyses, the Val105 allelic frequency showed positive association with the log-prevalence (partial r = 0.308, p = 0.042) and log-mortality of COVID-19 (partial r = 0.316, p = 0.037). The log-fatality did not show association with the allelic frequency. In the next step, only countries with the gross national income per capita more than $15,000 were included in the analysis. In the selected countries, the frequency of Val105 was positively associated with the log-prevalence (partial r = 0.456, p = 0.009) and log-mortality of COVID-19 (partial r = 0.544, p = 0.001).

Conclusions

The present findings indicate that countries with higher Val105 allelic frequency of the rs1695 polymorphism showed higher prevalence and mortality of COVID-19.

COVID-19 - Endothelial Axis and Coronary Artery Bypass Graft Patency: a Target for Therapeutic Intervention?

It has been reported that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces endothelial inflammation, therefore facilitating the progression of endothelial and vascular dysfunction in coronavirus disease 2019 (COVID-19) patients. Coronary artery bypass grafting (CABG) involves mainly the use of the saphenous vein (SV) and internal mammary artery as graft material in the stenosed coronary arteries. Unfortunately, graft patency of the SV is low due to endothelial dysfunction and inflammation. We propose that SARS-CoV-2 might cause vascular inflammation, endothelial dysfunction, and thrombosis in coronary artery bypass graft vessels by binding angiotensin-converting enzyme 2 receptor. Therefore, in this Special Article, we consider the potential influence of COVID-19 on the patency rates of coronary artery bypass graft vessels, mainly with reference to the SV. Moreover, we discuss the technique of SV graft harvesting and the therapeutic potential of focusing on endothelial dysfunction, vascular inflammation, and thrombosis for protecting coronary artery bypass grafts in COVID-19 infected CABG patients.

Angiotensin-converting enzyme 2, the complement system, the kallikrein-kinin system, type-2 diabetes, interleukin-6, and their interactions regarding the complex COVID-19 pathophysiological crossroads

Because of the current COVID-19-pandemic, the world is currently being held hostage in various lockdowns. ACE2 facilitates SARS-CoV-2 cell-entry, and is at the very center of several pathophysiological pathways regarding the RAAS, CS, KKS, T2DM, and IL-6. Their interactions with severe COVID-19 complications (e.g. ARDS and thrombosis), and potential therapeutic targets for pharmacological intervention, will be reviewed.

Is Toll-like receptor 4 involved in the severity of COVID-19 pathology in patients with cardiometabolic comorbidities?

The severe form of COVID-19 is marked by an abnormal and exacerbated immunological host response favoring to a poor outcome in a significant number of patients, especially those with obesity, diabetes, hypertension, and atherosclerosis. The chronic inflammatory process found in these cardiometabolic comorbidities is marked by the overexpression of pro-inflammatory cytokines such as interleukin-6 (IL-6) and tumoral necrosis factor-alpha (TNF-α), which are products of the Toll-Like receptors 4 (TLR4) pathway. The SARS-CoV-2 initially infects cells in the upper respiratory tract and, in some patients, spread very quickly, needing respiratory support and systemically, causing collateral damage in tissues. We hypothesize that this happens because the SARS-CoV-2 spike protein interacts strongly with TLR4, causing an intensely exacerbated immune response in the host's lungs, culminating with the cytokine storm, accumulating secretions and hindering blood oxygenation, along with the immune system attacks the body, leading to multiple organ failure.

Risk of venous thromboembolism in users of contraception and menopausal hormone therapy during the COVID-19 pandemic

OBJECTIVES

The outbreak of coronavirus disease (COVID-19) is a public health emergency of international concern. Inflammatory changes are part of COVID-19 pathophysiology and this might generate a higher thromboembolic risk in patients using combined hormonal contraception and menopausal hormone therapy. We aimed to discuss the main aspects related to this issue and propose management strategies for women affected by COVID-19.

METHODS

This narrative review collected information from several articles published since the beginning of the outbreak of the new coronavirus disease about the pathophysiology, stage of the disease, the occurrence of thrombotic events, and the risk of thromboembolism in users of contraception and hormonal therapy.

RESULTS

This article consolidates clinical parameters about the risk of venous thromboembolism in users of contraception and menopausal hormone therapy emphasizing the probable increase of that risk in women with suspected or confirmed COVID-19 and bringing safer recommendations.

CONCLUSIONS

In this scenario, apart from the fundamental orientations of preventive measures, like social isolation and hygiene, it is important that all female health professionals have knowledge of the new rules and adopt safety measures, especially on the prescription of hormonal therapy and contraception.

Mast Cells in Alveolar Septa of COVID-19 Patients: A Pathogenic Pathway That May Link Interstitial Edema to Immunothrombosis

It is currently believed that innate immunity is unable to prevent the spread of SARS-CoV-2 from the upper airways to the alveoli of high-risk groups of patients. SARS-CoV-2 replication in ACE-2-expressing pneumocytes can drive the diffuse alveolar injury through the cytokine storm and immunothrombosis by upregulating the transcription of chemokine/cytokines, unlike several other respiratory viruses. Here we report histopathology data obtained in post-mortem lung biopsies of COVID-19, showing the increased density of perivascular and septal mast cells (MCs) and IL-4-expressing cells (n = 6), in contrast to the numbers found in pandemic H1N1-induced pneumonia (n = 10) or Control specimens (n = 10). Noteworthy, COVID-19 lung biopsies showed a higher density of CD117+ cells, suggesting that c-kit positive MCs progenitors were recruited earlier to the alveolar septa. These findings suggest that MC proliferation/differentiation in the alveolar septa might be harnessed by the shift toward IL-4 expression in the inflamed alveolar septa. Future studies may clarify whether the fibrin-dependent generation of the hyaline membrane, processes that require the diffusion of procoagulative plasma factors into the alveolar lumen and the endothelial dysfunction, are preceded by MC-driven formation of interstitial edema in the alveolar septa.

Update on therapeutic approaches and emerging therapies for SARS-CoV-2 virus

The global pandemic of coronavirus disease 2019 (COVID-19), caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in over 7,273,958 cases with almost over 413,372 deaths worldwide as per the WHO situational report 143 on COVID-19. There are no known treatment regimens with proven efficacy and vaccines thus far, posing an unprecedented challenge to identify effective drugs and vaccines for prevention and treatment. The urgency for its prevention and cure has resulted in an increased number of proposed treatment options. The high rate and volume of emerging clinical trials on therapies for COVID-19 need to be compared and evaluated to provide scientific evidence for effective medical options. Other emerging non-conventional drug discovery techniques such as bioinformatics and cheminformatics, structure-based drug design, network-based methods for prediction of drug-target interactions, artificial intelligence (AI) and machine learning (ML) and phage technique could provide alternative routes to discovering potent Anti-SARS-CoV2 drugs. While drugs are being repurposed and discovered for COVID-19, novel drug delivery systems will be paramount for efficient delivery and avoidance of possible drug resistance. This review describes the proposed drug targets for therapy, and outcomes of clinical trials that have been reported. It also identifies the adopted treatment modalities that are showing promise, and those that have failed as drug candidates. It further highlights various emerging therapies and future strategies for the treatment of COVID-19 and delivery of Anti-SARS-CoV2 drugs.

Venous thromboembolism in the era of COVID-19

Coronavirus disease 2019 (COVID-19) does not only affect the respiratory system but appears to be a systemic disease. Venous thromboembolism is a common manifestation in hospitalized patients with COVID-19 with a reported incidence that is significantly higher compared to other acute viral infections. The pathophysiology mechanisms have not been fully explored and autopsy studies might enhance our understanding on this topic. Microthrombi formation occurs mainly in the pulmonary vasculature but can also occur in other organs. The high inflammatory burden related to COVID-19 seems to be associated with the coexisting coagulopathy. Concomitant manifestations of COVID-19, such as severe pneumonia, which has similar clinical presentation with pulmonary embolism (PE), and barriers related to strict isolation protocols are the two main reasons why PE diagnosis might be more challenging in patients with COVID-19. Medical societies have published guidance reports suggesting the administration of prophylactic anticoagulant therapy in hospitalized patients with COVID-19, but several questions regarding the optimal acute and long-term treatment of these patients remain unanswered.

Coagulation disorders in SARS-CoV-2 infection

A better understanding of the pathogenetic mechanisms triggered by SARS-CoV-2 infection may contribute to a more effective management of patients with COVID-19. Coagulation dysfunction is a key pathogenetic element of this disease as well as a challenge for practitioners. Marked inflammatory process found in severe forms of COVID-19, the complement activation, the cytokine storm, and disruption of the renin-angiotensin-aldosterone system are involved in the onset of thrombotic microangiopathy and large vessel coagulopathy. Virus-induced procoagulant activity occurs at the systemic level. Intravascular microthrombi disrupt vascularization in various tissues and organs, contributing to the occurrence of multiorgan failure and explain the higher morbidity and all-cause mortality of patients. It is estimated that almost 20% of patients with COVID-19 have significant coagulation disorders, and about a quarter of those hospitalized in intensive care units are prone to develop thrombosis events under prophylactic anticoagulant treatment. Some of patients who have been immunized after healing from the SARS-CoV-2 infection have a hypercoagulable state and are prone to develop thrombosis. Hypercoagulability is supported by thrombelastographic analysis: patients have an acceleration of the propagation phase of blood clot formation and higher clot strength. Markers of coagulation dysfunction in SARS-CoV2 are: decreased platelet count, increased INR, presence of fibrin degradation products, and especially higher plasma levels of D-dimers, which predict unfavorable outcome in these patients. Age, pre-existing diseases and associated risk factors, together with careful monitoring of clinical evolution and laboratory parameters allow the choice of the best personalized prophylactic or curative anticoagulant treatment.

A Clinical Pathway for Hospitalized Pediatric Patients With Initial SARS-CoV-2 Infection

The novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread quickly across the globe, creating unique and pressing challenges for today's physicians. Although this virus disproportionately affects adults, initial SARS-CoV-2 infection can present a significant disease burden for the pediatric population. A review of the literature yields descriptive studies in pediatric patients; however, no evidence-based or evidence-informed guidelines for the diagnosis and treatment of the hospitalized pediatric patient have been published in peer-reviewed journals. The authors, working at a quaternary care children's hospital in the national epicenter of the SARS-CoV-2 pandemic, found an urgent need to create a unified, multidisciplinary, evidence-informed set of guidelines for the diagnosis and management of coronavirus disease 2019 in children. In this article, the authors describe our institutional practices for the hospitalized pediatric patient with confirmed or suspected initial SARS-CoV-2 infection. The authors anticipate that developing evidence-informed and institution-specific guidelines will lead to improvements in care quality, efficiency, and consistency; minimization of staff risk of exposure to SARS-CoV-2; and increased provider comfort in caring for pediatric patients with SARS-CoV-2 infection.

Predictors of COVID-19 severity: a systematic review and meta-analysis

Background: The unpredictability of the progression of coronavirus disease 2019 (COVID-19) may be attributed to the low precision of the tools used to predict the prognosis of this disease. Objective: To identify the predictors associated with poor clinical outcomes in patients with COVID-19. Methods: Relevant articles from PubMed, Embase, Cochrane, and Web of Science were searched as of April 5, 2020. The quality of the included papers was appraised using the Newcastle-Ottawa scale (NOS). Data of interest were collected and evaluated for their compatibility for the meta-analysis. Cumulative calculations to determine the correlation and effect estimates were performed using the Z test. Results: In total, 19 papers recording 1,934 mild and 1,644 severe cases of COVID-19 were included. Based on the initial evaluation, 62 potential risk factors were identified for the meta-analysis. Several comorbidities, including chronic respiratory disease, cardiovascular disease, diabetes mellitus, and hypertension were observed more frequent among patients with severe COVID-19 than with the mild ones. Compared to the mild form, severe COVID-19 was associated with symptoms such as dyspnea, anorexia, fatigue, increased respiratory rate, and high systolic blood pressure. Lower levels of lymphocytes and hemoglobin; elevated levels of leukocytes, aspartate aminotransferase, alanine aminotransferase, blood creatinine, blood urea nitrogen, high-sensitivity troponin, creatine kinase, high-sensitivity C-reactive protein, interleukin 6, D-dimer, ferritin, lactate dehydrogenase, and procalcitonin; and a high erythrocyte sedimentation rate were also associated with severe COVID-19. Conclusion: More than 30 risk factors are associated with a higher risk of severe COVID-19. These may serve as useful baseline parameters in the development of prediction tools for COVID-19 prognosis.

Predictors of COVID-19 severity: a systematic review and meta-analysis

Background: The unpredictability of the progression of coronavirus disease 2019 (COVID-19) may be attributed to the low precision of the tools used to predict the prognosis of this disease. Objective: To identify the predictors associated with poor clinical outcomes in patients with COVID-19. Methods: Relevant articles from PubMed, Embase, Cochrane, and Web of Science were searched and extracted as of April 5, 2020. Data of interest were collected and evaluated for their compatibility for the meta-analysis. Cumulative calculations to determine the correlation and effect estimates were performed using the Z test. Results: In total, 19 papers recording 1,934 mild and 1,644 severe cases of COVID-19 were included. Based on the initial evaluation, 62 potential risk factors were identified for the meta-analysis. Several comorbidities, including chronic respiratory disease, cardiovascular disease, diabetes mellitus, and hypertension were observed more frequent among patients with severe COVID-19 than with the mild ones. Compared to the mild form, severe COVID-19 was associated with symptoms such as dyspnea, anorexia, fatigue, increased respiratory rate, and high systolic blood pressure. Lower levels of lymphocytes and hemoglobin; elevated levels of leukocytes, aspartate aminotransferase, alanine aminotransferase, blood creatinine, blood urea nitrogen, high-sensitivity troponin, creatine kinase, high-sensitivity C-reactive protein, interleukin 6, D-dimer, ferritin, lactate dehydrogenase, and procalcitonin; and a high erythrocyte sedimentation rate were also associated with severe COVID-19. Conclusion: More than 30 risk factors are associated with a higher risk of severe COVID-19. These may serve as useful baseline parameters in the development of prediction tools for COVID-19 prognosis.

Lymphopenia and neutrophilia at admission predicts severity and mortality in patients with COVID-19: a meta-analysis

BACKGROUND

There is a compelling need to identify clinical and laboratory predictors of unfavorable clinical course and death in patients with coronavirus disease (COVID-19). A trend towards low lymphocyte count and high neutrophil counts in patients with poor outcomes has been reported by earlier studies. We aim to synthesize existing data evaluating the relationship between clinical outcomes and abnormal neutrophil and lymphocyte counts at admission in COVID-19 patients.

METHODS

An electronic search was carried out in PubMed, China National Knowledge Infrastructure (CNKI) and Cochrane Central Register of Controlled Trials (CENTRAL) to identify eligible studies reporting frequency data on neutrophilia and lymphopenia at admission in hospitalization in COVID-19 patients. Pooled odds ratios of clinical outcomes for each parameter were calculated using Comprehensive Meta-Analysis.

RESULTS

A total of 22 studies (4,969 patients) were included in this meta-analysis. Lymphopenia at admission was found to be significantly associated with increased odd of progression to severe disease (odds ratio [OR], 4.20; 95% confidence interval [95CI%], 3.46-5.09) and death (OR, 3.71; 95%CI, 1.63-8.44). Neutrophilia at admission was also found to be significantly associated with increased odd of progression to severe disease (OR, 7.99; 95%CI, 1.77-36.14) and death (OR, 7.87; 95%CI, 1.75-35.35). Subgroup analysis revealed that COVID-19 patients with severe lymphopenia (<0.5 x10×9/L) had 12-fold increased odds of in-hospital mortality.

CONCLUSION

Admission lymphopenia and neutrophilia are associated with poor outcomes in patients with COVID-19. Regular monitoring and early and even more aggressive intervention shall hence be advisable in patients with low lymphocyte and high neutrophil counts. These variables may be useful in risk stratification models.

Coronavirus disease 2019 (COVID-19) and immune-mediated inflammatory rheumatic diseases: at the crossroads of thromboinflammation and autoimmunity

Inflammation and coagulation are key basic mechanism of protection against all potentially pathogenic mechanical and biological factors targeting human organism from inner and outer environment. On the other hand, uncontrolled inflammation results in hypercoagulation, inhibition of anticoagulation and alteration of mechanisms responsible for resolution of inflammation, while production of “procoagulant” mediators (thrombin, tissue factor and others), activation of platelets and of vascular endothelial cells maintains inflammation. All factors taken together serve as the basis for a pathological process called thromboinflammation or immunothrombosis. Currently thromboinflammation is considered in the broad sense as a universal pathogenetic mechanism of numerous widespread acute and chronic conditions, including immune-mediated (autoimmune) inflammatory rheumatic diseases, oftentimes complicated by severe irreversible damage to vital organs. Thromboinflammation gained specific attention during СОVID-19 (coronavirus disease 2019) pandemic, caused by SARS-Cov-2 (severe acute respiratory syndrome Coronavirus-2). COVID-19 is considered currently as systemic thromboinflammation syndrome, manifesting via generalized thrombosis of arterial and venous macro- and microvasculature, termed as COVID-19-coagulopathy. The paper discusses common pathogenetic coagulopathy mechanisms in COVID-19 and immune-mediated (autoimmune) inflammatory rheumatic diseases (IMRDs), associated with overproduction of antiphospholipid antibodies, activation of the complement system, and dis-regulated synthesis of proinflammatory cytokines, etc. Delineating the autoimmune subtype of thromboinflammation, identification of genetic (i.e., genes encoding the complement system and others) and molecular-biologic biomarkers associated with higher occurrence of COVID-19-coagulopathy are the most relevant undertakings for the current practice. Gaining insights into mechanisms of thromboinflammation and converting them into potential pharmacotherapies of IMDs would facilitate and accelerate the drafting of effective therapeutic strategies for COVID-19. 

The Critical Roles and Mechanisms of Immune Cell Death in Sepsis

Sepsis was first described by the ancient Greek physicians over 2000 years ago. The pathophysiology of the disease, however, is still not fully understood and hence the mortality rate is still unacceptably high due to lack of specific therapies. In the last decade, great progress has been made by shifting the focus of research from systemic inflammatory response syndrome (SIRS) to multiple organ dysfunction syndrome (MODS). Sepsis has been re-defined as infection-induced MODS in 2016. How infection leads to MODS is not clear, but what mediates MODS becomes the major topic in understanding the molecular mechanisms and developing specific therapies. Recently, the mechanism of infection-induced extensive immune cell death which releases a large quantity of damage-associated molecular patterns (DAMPs) and their roles in the development of MODS as well as immunosuppression during sepsis have attracted much attention. Growing evidence supports the hypothesis that DAMPs, including high-mobility group box 1 protein (HMGB1), cell-free DNA (cfDNA) and histones as well as neutrophil extracellular traps (NETs), may directly or indirectly contribute significantly to the development of MODS. Here, we provide an overview of the mechanisms and consequences of infection-induced extensive immune cell death during the development of sepsis. We also propose a pivotal pathway from a local infection to eventual sepsis and a potential combined therapeutic strategy for targeting sepsis.

Red Blood Cell Distribution Is a Significant Predictor of Severe Illness in Coronavirus Disease 2019

INTRODUCTION

As red blood cell distribution width (RDW) significantly predicts clinical outcomes in patients with respiratory tract infections and in those with critical illnesses, we performed a critical analysis of the literature to explore the potential prognostic role of this laboratory parameter in coronavirus disease 2019 (COVID-19).

METHODS

An electronic search was conducted in Medline, Scopus and Web of Science, using the keywords "coronavirus disease 2019" OR "COVID-19" AND "red blood cell distribution width" OR "RDW" in all fields, up to the present time, with no language restriction. Studies reporting the value of RDW-CV in CO-VID-19 patients with or without severe illness were included in a pooled analysis.

RESULTS

The pooled analysis included 3 studies, totaling 11,445 COVID-19 patients' samples (2,654 with severe disease; 23.2%). In all investigations RDW-CV was higher in COVID-19 patients with severe illness than in those with mild disease, with differences between 0.30 and 0.70%. The pooled analysis, despite consistent heterogeneity (I2: 88%), revealed that the absolute RDW-CV value was 0.69% higher (95% CI 0.40-0.98%; p < 0.001) in COVID-19 patients with severe illness compared to those with mild disease.

CONCLUSION

These results, along with data published in other studies, support the use of RDW for assessing the risk of unfavorable COVID-19 progression.

COVID-19: An up-to-date review - from morphology to pathogenesis

The entire world is under a devastating pandemic caused by COVID-19 with a high mortality rate. Knowledge of the viral structure, factors that help in its progression and spread, pathological findings, diagnostic methods and, treatment modalities helps in understanding the viral disease and also in treating the patients in a better way besides preventing the community spread of this deadly infection. The causative agent is a single- stranded RNA virus. The clinical spectrum varies in symptomatic and asymptomatic patients, who later become potential silent carriers, thus unknowingly spreading the virus. The virus constantly undergoes recombination, with reports of cross-species infections. Studies have indicated a strong immunological basis of COVID-19 infection. Not only does it weaken the immune system causing multi-organ involvement but also helps in its progression and spread to others.Multiple organs especially lungs, heart, kidney, gastrointestinal and hepatic system, brain and skin are affected varying in their severity. Similarly, persons with associated co-morbidities are likely to be affected more in terms of the number as well as in the severity. Real- time reverse transcription polymerase chain reaction confirms the presence of COVID-19 infection. Serological diagnosis helps in diagnosing an ongoing outbreak or retrospective infection. Furthermore, it also identifies individuals who have been infected or have recovered from the disease especially the asymptomatic. This helps in the development of an effective vaccine indicating the status of herd immunity in the community. Different treatment modalities are being tried and under trial. This review article thus highlights the global epidemiological status, characteristic of the virus, symptomatology of the patients, role of diagnostic tests available, organs affected including their morphological changes and the latest line of treatment of COVID-19.

Endothelial Dysfunction and Thrombosis in Patients With COVID-19-Brief Report

Supplemental Digital Content is available in the text.

Objective:

Alveolar-capillary endothelial cells can be activated by severe acute respiratory syndrome coronavirus 2 infection leading to cytokine release. This could trigger endothelial dysfunction, pyroptosis, and thrombosis, which are the vascular changes, commonly referred to as coronavirus disease 2019 (COVID-19) endotheliopathy. Thus, this study aimed to identify tissue biomarkers associated with endothelial activation/dysfunction and the pyroptosis pathway in the lung samples of patients with COVID-19 and to compare them to pandemic influenza A virus H1N1 subtype 2009 and control cases.

Approach and Results:

Postmortem lung samples (COVID-19 group =6 cases; H1N1 group =10 cases, and control group =11 cases) were analyzed using immunohistochemistry and the following monoclonal primary antibodies: anti-IL (interleukin)-6, anti-TNF (tumor necrosis factor)-α, anti-ICAM-1 (intercellular adhesion molecule 1), and anticaspase-1. From the result, IL-6, TNF-α, ICAM-1, and caspase-1 showed higher tissue expression in the COVID-19 group than in the H1N1 and control groups.

Conclusions:

Our results demonstrated endothelial dysfunction and suggested the participation of the pyroptosis pathway in the pulmonary samples. These conditions might lead to systemic thrombotic events that could impair the clinical staff’s efforts to avoid fatal outcomes. One of the health professionals’ goals should be to identify the high risk of thrombosis patients early to block endotheliopathy and its consequences.

More than Just Pneumonia: Acute Pulmonary Embolism in Two Middle-Aged Patients with COVID-19

Background

Although severe pneumonia and respiratory compromise have remained the predominant complications of coronavirus disease 19, we are now learning this virus is much more varied in its presentation. In particular, there are increasingly reported cases of thromboembolic events occurring in infected patients. Case Report. In this report, we present two patients, both under the age of 40 with known risk factors for venous thromboembolism, who presented with respiratory distress. Both patients were diagnosed with SARS-CoV-2 pneumonia and pulmonary embolism requiring management with anticoagulation. Both patients were discharged after a short course in the hospital.

Conclusion

The discussion of a hypercoagulable state induced by coronavirus disease 19 has been well documented; however, the exact mechanisms remain unknown. We suspect that a prothrombotic inflammatory response provoked by coronavirus disease could be the culprit, acting as an additive effect on middle-aged patients with known risk factors for venous thromboembolism. We recommend clinicians closely monitor those with known risk factors for pulmonary embolism.

The renin angiotensin aldosterone system and COVID-19

The ongoing pandemic has stimulated study of the Renin Angiotensin Aldosterone System (RAAS), and how it can be manipulated to treat COVID-19. Studies are examining whether drugs that act on the RAAS system might be useful to treat COVID-19. COVID-19 and the RAAS are closely linked both in infection and in possible post-infection inflammatory cascades. We detail the Physiology and Pharmacology of the RAAS including the effects of aldosterone and atrial natriuretic peptide. It is appropriate that the theoretical benefits of modulation of the RAAS should be considered based on available knowledge of the complexity of the system. In this short review we have tried to explain the actions of the angiotensin family of peptides and produce a relatively simple model and diagrammatic summary of the RAAS and the possible sites of intervention.

Laboratory abnormalities in children with mild and severe coronavirus disease 2019 (COVID-19): A pooled analysis and review

Limited data exists to-date on the laboratory findings in children with COVID-19, warranting the conduction of this study, in which we pool the currently available literature data on the laboratory findings seen in children with mild and severe COVID-19. Following an extensive literature search, we identified 24 eligible studies, including a total of 624 pediatric cases with laboratory-confirmed COVID-19, which report data on 27 different biomarkers. We then performed a meta-analysis to calculate the pooled prevalence estimates (PPE) for these laboratory abnormalities in mild COVID-19. As data was too limited for children with severe COVID-19 to allow pooling, results were presented descriptively in a summary of findings table. Our data show an inconsistent pattern of change in the leukocyte index of mild and severe cases of COVID-19 in children. Specifically, changes in leukocyte counts were only observed in 32% of the mild pediatric cases (PPE: 13% increase, 19% decrease). In mild disease, creatine kinase-MB (CK-MB) was frequently elevated, with a PPE of 33%. In severe disease, c-reactive protein (CRP), procalcitonin (PCT), and lactate dehydrogenase (LDH) were frequently elevated. Based on data obtained from early COVID-19 studies, leukocyte indices in children appear inconsistent, differing from those reported in adults that highlight specific leukocyte trends. This brings into question the utility and reliability of such parameters in monitoring disease severity in the pediatric population. Instead, we suggest physicians to serially monitor CRP, PCT, and LDH to track the course of illness in hospitalized children. Finally, elevated CK-MB in mild pediatric COVID-19 cases is indicative of possible cardiac injury. This highlights the importance of monitoring cardiac biomarkers in hospitalized patients and the need for further investigation of markers such as cardiac troponin in future studies.

Molecular, serological, and biochemical diagnosis and monitoring of COVID-19: IFCC taskforce evaluation of the latest evidence

The global coronavirus disease 2019 (COVID-19) has presented major challenges for clinical laboratories, from initial diagnosis to patient monitoring and treatment. Initial response to this pandemic involved the development, production, and distribution of diagnostic molecular assays at an unprecedented rate, leading to minimal validation requirements and concerns regarding their diagnostic accuracy in clinical settings. In addition to molecular testing, serological assays to detect antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are now becoming available from numerous diagnostic manufacturers. In both cases, the lack of peer-reviewed data and regulatory oversight, combined with general misconceptions regarding their appropriate use, have highlighted the importance of laboratory professionals in robustly validating and evaluating these assays for appropriate clinical use. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Task Force on COVID-19 has been established to synthesize up-to-date information on the epidemiology, pathogenesis, and laboratory diagnosis and monitoring of COVID-19, as well as to develop practical recommendations on the use of molecular, serological, and biochemical tests in disease diagnosis and management. This review summarizes the latest evidence and status of molecular, serological, and biochemical testing in COVID-19 and highlights some key considerations for clinical laboratories operating to support the global fight against this ongoing pandemic. Confidently this consolidated information provides a useful resource to laboratories and a reminder of the laboratory's critical role as the world battles this unprecedented crisis.

IMMUNOPATHOLOGY AND IMMUNOPHARMACOTHERAPY OF CORONAVIRUS DISEASE 2019 (COVID-19): FOCUS ON INTERLEUKIN 6

The Coronavirus Disease 2019 (COVID-19) pandemic has drawn closer attention than ever before to the problems of the immunopathology of human diseases, many of which have been reflected when studying immune-mediated inflammatory rheumatic diseases (IIRDs). The hyperimmune response called a cytokine storm, the pathogenetic subtypes of which include hemophagocytic lymphohistiocytosis, macrophage activation syndrome, and cytokine release syndrome, is among the most serious complications of IIRDs or treatment for malignant neoplasms and may be a stage of COVID-19 progression. A premium is placed to interleukin-6 (IL-6) in the spectrum of cytokines involved in the pathogenesis of the cytokine storm syndrome. The clinical introduction of monoclonal antibodies (mAbs) that inhibit the activity of this cytokine (tocilizumab, sarilumab, etc.) is one of the major advances in the treatment of IIRDs and critical conditions within the cytokine storm syndrome in COVID-19. The review discusses data on the clinical and prognostic value of IL-6 and the effectiveness of anti-IL-6 receptor and anti-IL-6 mAbs, as well as prospects for personalized therapy of the cytokine storm syndrome in COVID-19.