A comprehensive review on potential therapeutics interventions for COVID-19

In Silico and In Vitro Evaluation of the Molecular Mimicry of the SARS-CoV-2 Spike Protein by Common Short Constituent Sequences (cSCSs) in the Human Proteome: Toward Safer Epitope Design for Vaccine Development

Spike protein sequences in SARS-CoV-2 have been employed for vaccine epitopes, but many short constituent sequences (SCSs) in the spike protein are present in the human proteome, suggesting that some anti-spike antibodies induced by infection or vaccination may be autoantibodies against human proteins. To evaluate this possibility of "molecular mimicry" in silico and in vitro, we exhaustively identified common SCSs (cSCSs) found both in spike and human proteins bioinformatically. The commonality of SCSs between the two systems seemed to be coincidental, and only some cSCSs were likely to be relevant to potential self-epitopes based on three-dimensional information. Among three antibodies raised against cSCS-containing spike peptides, only the antibody against EPLDVL showed high affinity for the spike protein and reacted with an EPLDVL-containing peptide from the human unc-80 homolog protein. Western blot analysis revealed that this antibody also reacted with several human proteins expressed mainly in the small intestine, ovary, and stomach. Taken together, these results showed that most cSCSs are likely incapable of inducing autoantibodies but that at least EPLDVL functions as a self-epitope, suggesting a serious possibility of infection-induced or vaccine-induced autoantibodies in humans. High-risk cSCSs, including EPLDVL, should be excluded from vaccine epitopes to prevent potential autoimmune disorders.

Can Probiotics, Particularly Limosilactobacillus fermentum UCO-979C and Lacticaseibacillus rhamnosus UCO-25A, Be Preventive Alternatives against SARS-CoV-2?

COVID-19, an infection produced by the SARS-CoV-2 virus in humans, has rapidly spread to become a high-mortality pandemic. SARS-CoV-2 is a single-stranded RNA virus characterized by infecting epithelial cells of the intestine and lungs, binding to the ACE2 receptor present on epithelial cells. COVID-19 treatment is based on antivirals and antibiotics against symptomatology in addition to a successful preventive strategy based on vaccination. At this point, several variants of the virus have emerged, altering the effectiveness of treatments and thereby attracting attention to several alternative therapies, including immunobiotics, to cope with the problem. This review, based on articles, patents, and an in silico analysis, aims to address our present knowledge of the COVID-19 disease, its symptomatology, and the possible beneficial effects for patients if probiotics with the characteristics of immunobiotics are used to confront this disease. Moreover, two probiotic strains, L. fermentum UCO-979C and L. rhamnosus UCO-25A, with different effects demonstrated at our laboratory, are emphasized. The point of view of this review highlights the possible benefits of probiotics, particularly those associated with immunomodulation as well as the production of secondary metabolites, and their potential targets during SARS-CoV-2 infection.

A review on structural, non-structural, and accessory proteins of SARS-CoV-2: Highlighting drug target sites

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, is a highly transmittable and pathogenic human coronavirus that first emerged in China in December 2019. The unprecedented outbreak of SARS-CoV-2 devastated human health within a short time leading to a global public health emergency. A detailed understanding of the viral proteins including their structural characteristics and virulence mechanism on human health is very crucial for developing vaccines and therapeutics. To date, over 1800 structures of non-structural, structural, and accessory proteins of SARS-CoV-2 are determined by cryo-electron microscopy, X-ray crystallography, and NMR spectroscopy. Designing therapeutics to target the viral proteins has several benefits since they could be highly specific against the virus while maintaining minimal detrimental effects on humans. However, for ongoing and future research on SARS-CoV-2, summarizing all the viral proteins and their detailed structural information is crucial. In this review, we compile comprehensive information on viral structural, non-structural, and accessory proteins structures with their binding and catalytic sites, different domain and motifs, and potential drug target sites to assist chemists, biologists, and clinicians finding necessary details for fundamental and therapeutic research.

Prophylactic and therapeutic insights into trained immunity: A renewed concept of innate immune memory

Trained immunity is a renewed concept of innate immune memory that facilitates the innate immune system to have the capacity to remember and train cells via metabolic and transcriptional events to enable them to provide nonspecific defense against the subsequent encounters with a range of pathogens and acquire a quicker and more robust immune response, but different from the adaptive immune memory. Reversing the epigenetic changes or targeting the immunological pathways may be considered potential therapeutic approaches to counteract the hyper-responsive or hypo-responsive state of trained immunity. The efficient regulation of immune homeostasis and promotion or inhibition of immune responses is required for a balanced response. Trained immunity-based vaccines can serve as potent immune stimuli and help in the clearance of pathogens in the body through multiple or heterologous effects and confer protection against nonspecific and specific pathogens. This review highlights various features of trained immunity and its applications in developing novel therapeutics and vaccines, along with certain detrimental effects, challenges as well as future perspectives.

What the American Journal of Critical Care Junior Peer Reviewers Were Reading During Year 2 of the Program

The American Journal of Critical Care's Junior Peer Reviewer program aims to mentor novice reviewers in the peer review process. To grow their critical appraisal skills, the participants take part in discussion sessions in which they review articles published in other journals. Here we summarize the articles reviewed during the second year of the program, which again focused on the care of critically ill patients with COVID-19. This article aims to share these reviews and the reviewers' thoughts regarding the relevance, design, and applicability of the findings from the selected studies. High rates of delirium associated with COVID-19 may be impacted by optimizing sedation strategies and allowing safe family visitation. Current methodology in crisis standards of care may result in inequity and further research is needed. The use of extracorporeal carbon dioxide removal to facilitate super low tidal volume ventilation does not improve 90-day mortality outcomes. Continued research to better understand the natural history of COVID-19 and interventions useful for improving outcomes is imperative.

Development of extra-fine particles containing nanosized meloxicam for deep pulmonary delivery: in vitro aerodynamic and cell line measurements

Pulmonary drug administration provides a platform for the effective local treatment of various respiratory diseases. Application of nano-sized active ingredients results in higher bioavailability because of their large specific surface area. Extra-fine dry powder inhalers reach the smaller airways, further improving therapeutic efficiency. Poorly water-soluble meloxicam was the selected active ingredient. We aimed to decrease the particle size into the nano range by wet milling and producing extra-fine inhalable particles via nano spray-drying. The diameter of the drug was reduced to 138 nm. The particle size of the dry products was between 1.1-1.5 µm, and the dispersed diameter was between 500-800 nm. Owing to the excipients (poly-vinyl-alcohol, leucine), the spray-dried particles presented nearly spherical morphology. The drug became partially amorphous. Thanks to the improved surface area, the solubility and the released and the diffused amount of the meloxicam increased in artificial lung media. The in vitro aerodynamic measurements showed that the leucine-containing formulations had outstanding fine particle fraction (FPF) deposition with 1.3 µm mass median aerodynamic diameter (MMAD). The aerodynamic particle counter test also proved the extra-fine aerodynamic particle size. The in vitro cell line experiments revealed the non-cytotoxicity of the products and the suppression of the interleukin concentration. Overall, the powders are suitable for deep pulmonary delivery and the local treatment of lung inflammations.

Impact of Coronavirus Disease 2019 on the Pediatric Population with Aerodigestive Disease

OBJECTIVE

To determine the impact of the coronavirus disease 2019 (COVID-19) quarantine on baseline health, medication use, health anxiety, and healthcare use in pediatric patients with aerodigestive disease and to evaluate for associations of commonly prescribed medications with the risk of COVID-19 illness.

STUDY DESIGN

Prospective study of patients presenting in person to pediatric neurogastroenterology clinics between July 2020 and March 2021.

RESULTS

Of 202 recruited patients, 71.3% were seen in the aerodigestive diseases center and 28.7% in the functional abdominal pain (FAP)/motility clinic. Of all patients, 25.1% reported improved overall health during quarantine; patients with aerodigestive disease (35.3%) reported higher rates of improved overall health compared with patients with FAP/motility disorders (3.6%, P = .0001). Patients with aerodigestive disease had fewer airway symptoms (P < .05) and less medication use during quarantine (inhaled steroids, P < .05 and albuterol, P < .05). Despite objective improvement, there was significant health-related anxiety, with greater anxiety scores reported during and at the end of quarantine (P < .05), with no difference between patient groups (P > .11). Patients continued to access healthcare during quarantine. In total, 28.7% of patients were seen in the emergency department (patients with FAP more than patients with aerodigestive disease, P = .02), and 19.8% were hospitalized. COVID-19 testing was performed in 58.4% of patients and 2.0% (n = 4) of the entire cohort tested positive.

CONCLUSIONS

Patients with aerodigestive disease show improvement of airway symptoms and decreased use of medications during the pandemic, despite increased health-related anxiety. Despite complexities of accessing care due to the widespread lockdown, all patient groups continued to access healthcare.

Hydrogen-oxygen therapy alleviates clinical symptoms in twelve patients hospitalized with COVID-19: A retrospective study of medical records

A global public health crisis caused by the 2019 novel coronavirus disease (COVID-19) leads to considerable morbidity and mortality, which bring great challenge to respiratory medicine. Hydrogen-oxygen therapy contributes to treat severe respiratory diseases and improve lung functions, yet there is no information to support the clinical use of this therapy in the COVID-19 pneumonia.A retrospective study of medical records was carried out in Shishou Hospital of Traditional Chinese Medicine in Hubei, China. COVID-19 patients (aged ≥ 30 years) admitted to the hospital from January 29 to March 20, 2020 were subjected to control group (n = 12) who received routine therapy and case group (n = 12) who received additional hydrogen-oxygen therapy. The clinical characteristics of COVID-19 patients were analyzed. The physiological and biochemical indexes, including immune inflammation indicators, electrolytes, myocardial enzyme profile, and functions of liver and kidney, were examined and investigated before and after hydrogen-oxygen therapy.The results showed significant decreases in the neutrophil percentage and the concentration and abnormal proportion of C-reactive protein in COVID-19 patients received additional hydrogen-oxygen therapy.This novel therapeutic may alleviate clinical symptoms of COVID-19 patients by suppressing inflammation responses.

Survival of COVID-19 Patients Who Received Antiviral and Antiviral Therapy Combined with Anti-inflammation Therapy in a National Referral Hospital, Indonesia

Background: COVID-19 has infected and spread over the whole earth. For the time being, there is no cure for COVID 19. Although several medications have the potential to be utilized at various stages of the disease, no therapy has yet been demonstrated to be completely successful. Aim: This study aims to determine survival of COVID-19 patients who received antiviral and antiviral therapy combined with anti-inflammation therapy in a national referral hospital Indonesia. Methods: COVID-19 patients treated at Dr. M Djamil General Hospital in Padang, Indonesia were the subject of an analytic investigation using a retrospective cohort design. From January to June 2021, data was gathered from patient medical records. Independent sample T test and Chi-square test were used to analyze subject characteristics data. The median survival and survival rates were calculated using Kaplan-Meier survival analysis. It is also subjected to cox-regression analysis in order to answer the study hypothesis. Results: The mean age of the subjects who received antiviral and anti-inflammatory medication was 60.95 12.11 years, while the average age of those who received antiviral therapy was 56.72 17.80 years, with the highest sex being male in both groups (59.3 percent ; 50.6 percent ). Antiviral and antiviral medication, as well as anti-inflammatory therapy, had no effect on the length of stay of COVID-19 patients (p>0.05). Antiviral and antiviral therapy, as well as anti-inflammatory therapy, play a role in the outcome of COVID-19 patients (p<0.05), with patients receiving antiviral and anti-inflammatory therapy being a preventive factor in the final outcome of patients compared to patients receiving antiviral therapy HR = 0.69 (95% CI 0.48-0.99). Conclusion: When compared to patients who just got antiviral medication, patients who received antiviral plus anti-inflammatory therapy had a better outcome.

Wave comparisons of clinical characteristics and outcomes of COVID-19 admissions - Exploring the impact of treatment and strain dynamics

OBJECTIVES

Dexamethasone has now been incorporated into the standard of care for COVID-19 hospital patients. However, larger intensive care unit studies have failed to show discernible improvements in mortality in the recent wave. We aimed to investigate the impacts of these factors on disease outcomes in a UK hospital study.

METHODS

This retrospective observational study reports patient characteristics, interventions and outcomes in COVID-19 patients from a UK teaching hospital; cohort 1, pre 16th June-2020 (pre-dexamethasone); cohort 2, 17th June to 30th November-2020 (post-dexamethasone, pre-VOC 202,012/01 as dominant strain); cohort 3, 1st December-2020 to 3rd March-2021 (during establishment of VOC202012/01 as the dominant strain).

RESULTS

Dexamethasone treatment was more common in cohorts 2 and 3 (42.7% and 51.6%) compared with cohort 1 (2.5%). After adjusting for risk, odds of death within 28 days were 2-fold lower in cohort 2 vs 1 (OR:0.47,[0.27,0.79],p = 0.006). Mortality was higher cohort 3 vs 2 (20% vs 14%); but not significantly different to cohort 1 (OR: 0.86,[0.64, 1.15],p = 0.308).

CONCLUSIONS

The real world finding of lower mortality following dexamethasone supports the published trial evidence and highlights ongoing need for research with introduction of new treatments and ongoing concern over new COVID-19 variants.

Potential value of pharmacological agents acting on toll-like receptor (TLR) 7 and/or TLR8 in COVID-19

The COVID-19 pandemic is an ongoing global pandemic of coronavirus disease 2019 as an atypical type of viral pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Many potential pharmacotherapies are currently being investigated against this disease. This article points to and justifies, the importance of investigating the potential therapeutic value of pharmacological agents acting on Toll-like Receptor (TLR) 7 and/or TLR8 as double-edged swords combating COVID-19. Induction of TLR7 and/or TLR8 may be investigated as a strategy to stimulate immunity and may be added to anti-COVID19 vaccines to cope with their current viral escape challenge. TLR7 stimulation may not only help viral clearance through Th1 antiviral responses but may also provide beneficial broncho- and vaso-dilatory, as well as, anti-inflammatory effects. Pharmacological compounds acting as TLR7 and/or TLR8 agonists may be of value if used by frontline healthcare workers with comorbidities who demonstrate mild symptoms of the disease. On the other hand, TLR7 and/or TLR8 antagonists may be used in combination with immune-modulatory/anti-inflammatory drugs in severe cases of the disease, with potential synergistic effects that could also help in reducing the doses of such therapies, and consequently their adverse effects.

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There is potential value in development of TLR7/8 agonists/antagonists as double-edged swords combating COVID-19.

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TLR7/8 agonists, as immune-stimulants in mild disease, may also be added to preventive vaccines acting against viral escape.

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TLR7/8 antagonists may be combined with immune-suppressants in severe cases for potential synergism and minimized toxicity.

Multi-omic approach identifies a transcriptional network coupling innate immune response to proliferation in the blood of COVID-19 cancer patients

Clinical outcomes of COVID-19 patients are worsened by the presence of co-morbidities, especially cancer leading to elevated mortality rates. SARS-CoV-2 infection is known to alter immune system homeostasis. Whether cancer patients developing COVID-19 present alterations of immune functions which might contribute to worse outcomes have so far been poorly investigated. We conducted a multi-omic analysis of immunological parameters in peripheral blood mononuclear cells (PBMCs) of COVID-19 patients with and without cancer. Healthy donors and SARS-CoV-2-negative cancer patients were also included as controls. At the infection peak, cytokine multiplex analysis of blood samples, cytometry by time of flight (CyTOF) cell population analyses, and Nanostring gene expression using Pancancer array on PBMCs were performed. We found that eight pro-inflammatory factors (IL-6, IL-8, IL-13, IL-1ra, MIP-1a, IP-10) out of 27 analyzed serum cytokines were modulated in COVID-19 patients irrespective of cancer status. Diverse subpopulations of T lymphocytes such as CD8+T, CD4+T central memory, Mucosal-associated invariant T (MAIT), natural killer (NK), and γδ T cells were reduced, while B plasmablasts were expanded in COVID-19 cancer patients. Our findings illustrate a repertoire of aberrant alterations of gene expression in circulating immune cells of COVID-19 cancer patients. A 19-gene expression signature of PBMCs is able to discriminate COVID-19 patients with and without solid cancers. Gene set enrichment analysis highlights an increased gene expression linked to Interferon α, γ, α/β response and signaling which paired with aberrant cell cycle regulation in cancer patients. Ten out of the 19 genes, validated in a real-world consecutive cohort, were specific of COVID-19 cancer patients independently from different cancer types and stages of the diseases, and useful to stratify patients in a COVID-19 disease severity-manner. We also unveil a transcriptional network involving gene regulators of both inflammation response and proliferation in PBMCs of COVID-19 cancer patients.

Deep learning in target prediction and drug repositioning: Recent advances and challenges

Drug repositioning is an attractive strategy for discovering new therapeutic uses for approved or investigational drugs, with potentially shorter development timelines and lower development costs. Various computational methods have been used in drug repositioning, promoting the efficiency and success rates of this approach. Recently, deep learning (DL) has attracted wide attention for its potential in target prediction and drug repositioning. Here, we provide an overview of the basic principles of commonly used DL architectures and their applications in target prediction and drug repositioning, and discuss possible ways of dealing with current challenges to help achieve its expected potential for drug repositioning.

Identifying New COVID-19 Receptor Neuropilin-1 in Severe Alzheimer's Disease Patients Group Brain Using Genome-Wide Association Study Approach

Recent preclinical studies show that Neuropilin-1 (NRP1), which is a transmembrane protein with roles in neuronal development, axonal outgrowth, and angiogenesis, also plays a role in the infectivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Thus, we hypothesize that NRP1 may be upregulated in Alzheimer's disease (AD) patients and that a correlation between AD and SARS-CoV-2 NRP1-mediated infectivity may exist as angiotensin converting enzyme 2 (ACE2). We used an AD mouse model that mimics AD and performed high-throughput total RNA-seq with brain tissue and whole blood. For quantification of NRP1 in AD, brain tissues and blood were subjected to Western blotting and real-time quantitative PCR (RT-qPCR) analysis. In silico analysis for NRP1 expression in AD patients has been performed on human hippocampus data sets. Many cases of severe symptoms of COVID-19 are concentrated in an elderly group with complications such as diabetes, degenerative disease, and brain disorders. Total RNA-seq analysis showed that the Nrp1 gene was commonly overexpressed in the AD model. Similar to ACE2, the NRP1 protein is also strongly expressed in AD brain tissues. Interestingly, in silico analysis revealed that the level of expression for NRP1 was distinct at age and AD progression. Given that NRP1 is highly expressed in AD, it is important to understand and predict that NRP1 may be a risk factor for SARS-CoV-2 infection in AD patients. This supports the development of potential therapeutic drugs to reduce SARS-CoV-2 transmission.

Impact of Psychiatric and Related Somatic Medications on the Duration and Severity of COVID-19: A Retrospective Explorative Multi-center Study from the German Metropolitan Ruhr-area

INTRODUCTION

Several psychiatric and somatic medications are assumed to improve COVID-19-symptoms. These include antidepressants, antipsychotics, and anticonvulsants as well as anticoagulants, statins, and renin-angiotensin-aldosterone-system (RAAS)-inhibitors for somatic comorbid conditions. All these agents may reduce the hyperinflammatory response to SARS/CoV-2 or the related negative cardio-cerebrovascular outcomes.

METHODS

In a retrospective longitudinal, multi-center inpatient study, we sought to explore the influence of psychiatric medications on COVID-19, comprising the period from diagnosing SARS/CoV-2-infection via PCR (nasopharyngeal swab) up to the next 21 days. Ninety-six psychiatric inpatients (mean age [SD] 65.5 (20.1), 54% females) were included. The primary outcome was the COVID-19-duration. Secondary outcomes included symptom severity and the presence of residual symptoms.

RESULTS

COVID-19-related symptoms emerged in 60 (62.5%) patients, lasting 6.5 days on average. Six (6.3%) 56-95 years old patients died from or with COVID-19. COVID-19-duration and residual symptom-presence (n=22, 18%) were not significantly related to any substance. Respiratory and neuro-psychiatric symptom-load was significantly and negatively related to prescription of antidepressants and anticoagulants, respectively. Fatigue was negatively and positively related to RAAS-inhibitors and proton-pump-inhibitors, respectively. These significant relationships disappeared with p-value adjustment owed to multiple testing. The mean total psychiatric burden was not worsened across the study.

DISCUSSION

None of the tested medications was significantly associated with the COVID-19-duration and -severity up to the end of post-diagnosing week 3. However, there were a few biologically plausible and promising relationships with antidepressants, anticoagulants, and RAAS-inhibitors before p-value adjustment. These should encourage larger and prospective studies to re-evaluate the influence of somatic and psychiatric routine medications on COVID-19-related health outcomes.

Computational Analysis Illustrates the Mechanism of Qingfei Paidu Decoction in Blocking the Transition of COVID-19 Patients from Mild to Severe Stage

BACKGROUND

The epidemic of SARS-CoV-2 has made COVID-19 a serious threat to human health around the world. The severe infections of SARS-CoV-2 are usually accompanied by higher mortality. Although the Qingfei Paidu Decoction (QFPDD) has been proved to be effective in blocking the transition of COVID-19 patients from mild to severe stage, its mechanism remains unclear.

OBJECTIVE

This study aims to explore the mechanism of QFPDD in blocking the transition of COVID-19 patients from mild to severe stage.

MATERIALS AND METHODS

In the process of screening active ingredients, oral bioavailability (OB) and drug likeness (DL) are key indicators, which can help to screen out pivotal compounds. Therefore, with the criteria of OB≥30% and DL≥0.18 , we searched active ingredients of QFPDD in the Traditional Chinese Medicine Systems Pharmacology (TCMSP, https://tcmspw.com/) by using its 21 herbs as keywords.

RESULTS

We filtered out 6 pivotal ingredients from QFPDD by using the bioinformatics method, namely quercetin, luteolin, berberine, hederagenin, shionone and kaempferol, which can inhibit the highly expressed genes (i.e. CXCR4, ICAM1, CXCL8, CXCL10, IL6, IL2, CCL2, IL1B, IL4, IFNG) in severe COVID-19 patients. By performing KEGG enrichment analysis, we found seven pathways, namely TNF signaling pathway, IL-17 signaling pathway, Toll-like receptor signaling pathway, NF-kappa B signaling pathway, HIF-1 signaling pathway, JAK-STAT signaling pathway, and Th17 cell differentiation, by which QFPDD could block the transition of COVID-19 patients from mild to severe stage.

CONCLUSION

QFPDD can prevent the deterioration of COVID-19 in the following mechanisms, i.e. inhibiting SARS-CoV-2 invasion and replication, anti-inflammatory and immune regulation, and repairing body damage. These results will be helpful for the prevention and treatment of COVID-19.

7-Ketocholesterol: Effects on viral infections and hypothetical contribution in COVID-19

7-Ketocholesterol, which is one of the earliest cholesterol oxidization products identified, is essentially formed by the auto-oxidation of cholesterol. In the body, 7-ketocholesterol is both provided by food and produced endogenously. This pro-oxidant and pro-inflammatory molecule, which can activate apoptosis and autophagy at high concentrations, is an abundant component of oxidized Low Density Lipoproteins. 7-Ketocholesterol appears to significantly contribute to the development of age-related diseases (cardiovascular diseases, age-related macular degeneration, and Alzheimer's disease), chronic inflammatory bowel diseases and to certain cancers. Recent studies have also shown that 7-ketocholesterol has anti-viral activities, including on SARS-CoV-2, which are, however, lower than those of oxysterols resulting from the oxidation of cholesterol on the side chain. Furthermore, 7-ketocholesterol is increased in the serum of moderately and severely affected COVID-19 patients. In the case of COVID-19, it can be assumed that the antiviral activity of 7-ketocholesterol could be counterbalanced by its toxic effects, including pro-oxidant, pro-inflammatory and pro-coagulant activities that might promote the induction of cell death in alveolar cells. It is therefore suggested that this oxysterol might be involved in the pathophysiology of COVID-19 by contributing to the acute respiratory distress syndrome and promoting a deleterious, even fatal outcome. Thus, 7-ketocholesterol could possibly constitute a lipid biomarker of COVID-19 outcome and counteracting its toxic effects with adjuvant therapies might have beneficial effects in COVID-19 patients.

Endothelial Dysfunction, Inflammation, and Oxidative Stress in COVID-19-Mechanisms and Therapeutic Targets

The outbreak of the COVID-19 pandemic represents an ongoing healthcare emergency responsible for more than 3.4 million deaths worldwide. COVID-19 is the disease caused by SARS-CoV-2, a virus that targets not only the lungs but also the cardiovascular system. COVID-19 can manifest with a wide range of clinical manifestations, from mild symptoms to severe forms of the disease, characterized by respiratory failure due to severe alveolar damage. Several studies investigated the underlying mechanisms of the severe lung damage associated with SARS-CoV-2 infection and revealed that the respiratory failure associated with COVID-19 is the consequence not only of acute respiratory distress syndrome but also of macro- and microvascular involvement. New observations show that COVID-19 is an endothelial disease, and the consequent endotheliopathy is responsible for inflammation, cytokine storm, oxidative stress, and coagulopathy. In this review, we show the central role of endothelial dysfunction, inflammation, and oxidative stress in the COVID-19 pathogenesis and present the therapeutic targets deriving from this endotheliopathy.

Diverse Immunological Factors Influencing Pathogenesis in Patients with COVID-19: A Review on Viral Dissemination, Immunotherapeutic Options to Counter Cytokine Storm and Inflammatory Responses

The pathogenesis of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still not fully unraveled. Though preventive vaccines and treatment methods are out on the market, a specific cure for the disease has not been discovered. Recent investigations and research studies primarily focus on the immunopathology of the disease. A healthy immune system responds immediately after viral entry, causing immediate viral annihilation and recovery. However, an impaired immune system causes extensive systemic damage due to an unregulated immune response characterized by the hypersecretion of chemokines and cytokines. The elevated levels of cytokine or hypercytokinemia leads to acute respiratory distress syndrome (ARDS) along with multiple organ damage. Moreover, the immune response against SARS-CoV-2 has been linked with race, gender, and age; hence, this viral infection's outcome differs among the patients. Many therapeutic strategies focusing on immunomodulation have been tested out to assuage the cytokine storm in patients with severe COVID-19. A thorough understanding of the diverse signaling pathways triggered by the SARS-CoV-2 virus is essential before contemplating relief measures. This present review explains the interrelationships of hyperinflammatory response or cytokine storm with organ damage and the disease severity. Furthermore, we have thrown light on the diverse mechanisms and risk factors that influence pathogenesis and the molecular pathways that lead to severe SARS-CoV-2 infection and multiple organ damage. Recognition of altered pathways of a dysregulated immune system can be a loophole to identify potential target markers. Identifying biomarkers in the dysregulated pathway can aid in better clinical management for patients with severe COVID-19 disease. A special focus has also been given to potent inhibitors of proinflammatory cytokines, immunomodulatory and immunotherapeutic options to ameliorate cytokine storm and inflammatory responses in patients affected with COVID-19.

8806 Russian patients demonstrate T cell count as better marker of COVID-19 clinical course severity than SARS-CoV-2 viral load

The article presents a comparative analysis of SARS-CoV-2 viral load (VL), T lymphocyte count and respiratory index PaO₂:FiO₂ ratio as prospective markers of COVID-19 course severity and prognosis. 8806 patients and asymptomatic carriers were investigated in time interval 15 March–19 December 2020. T cell count demonstrated better applicability as a marker of aggravating COVID-19 clinical course and unfavourable disease prognosis than SARS-CoV-2 VL or PaO₂:FiO₂ ratio taken alone. Using T cell count in clinical practice may provide an opportunity of early prediction of deteriorating a patient’s state.

Role of Inflammatory Cytokines in COVID-19 Patients: A Review on Molecular Mechanisms, Immune Functions, Immunopathology and Immunomodulatory Drugs to Counter Cytokine Storm

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a severe pandemic of the current century. The vicious tentacles of the disease have been disseminated worldwide with unknown complications and repercussions. Advanced COVID-19 syndrome is characterized by the uncontrolled and elevated release of pro-inflammatory cytokines and suppressed immunity, leading to the cytokine storm. The uncontrolled and dysregulated secretion of inflammatory and pro-inflammatory cytokines is positively associated with the severity of the viral infection and mortality rate. The secretion of various pro-inflammatory cytokines such as TNF-α, IL-1, and IL-6 leads to a hyperinflammatory response by recruiting macrophages, T and B cells in the lung alveolar cells. Moreover, it has been hypothesized that immune cells such as macrophages recruit inflammatory monocytes in the alveolar cells and allow the production of large amounts of cytokines in the alveoli, leading to a hyperinflammatory response in severely ill patients with COVID-19. This cascade of events may lead to multiple organ failure, acute respiratory distress, or pneumonia. Although the disease has a higher survival rate than other chronic diseases, the incidence of complications in the geriatric population are considerably high, with more systemic complications. This review sheds light on the pivotal roles played by various inflammatory markers in COVID-19-related complications. Different molecular pathways, such as the activation of JAK and JAK/STAT signaling are crucial in the progression of cytokine storm; hence, various mechanisms, immunological pathways, and functions of cytokines and other inflammatory markers have been discussed. A thorough understanding of cytokines' molecular pathways and their activation procedures will add more insight into understanding immunopathology and designing appropriate drugs, therapies, and control measures to counter COVID-19. Recently, anti-inflammatory drugs and several antiviral drugs have been reported as effective therapeutic drug candidates to control hypercytokinemia or cytokine storm. Hence, the present review also discussed prospective anti-inflammatory and relevant immunomodulatory drugs currently in various trial phases and their possible implications.

COVID-19: Characteristics and Therapeutics

Novel coronavirus (COVID-19 or 2019-nCoV or SARS-CoV-2), which suddenly emerged in December 2019 is still haunting the entire human race and has affected not only the healthcare system but also the global socioeconomic balances. COVID-19 was quickly designated as a global pandemic by the World Health Organization as there have been about 98.0 million confirmed cases and about 2.0 million confirmed deaths, as of January 2021. Although, our understanding of COVID-19 has significantly increased since its outbreak, and multiple treatment approaches and pharmacological interventions have been tested or are currently under development to mitigate its risk-factors. Recently, some vaccine candidates showed around 95% clinical efficacy, and now receiving emergency use approvals in different countries. US FDA recently approved BNT162 and mRNA-1273 vaccines developed by Pfizer/BioNTech and Moderna Inc. for emergency use and vaccination in the USA. In this review, we present a succinct overview of the SARS-CoV-2 virus structure, molecular mechanisms of infection, COVID-19 epidemiology, diagnosis, and clinical manifestations. We also systematize different treatment strategies and clinical trials initiated after the pandemic outbreak, based on viral infection and replication mechanisms. Additionally, we reviewed the novel pharmacological intervention approaches and vaccine development strategies against COVID-19. We speculate that the current pandemic emergency will trigger detailed studies of coronaviruses, their mechanism of infection, development of systematic drug repurposing approaches, and novel drug discoveries for current and future pandemic outbreaks.

The Worldwide Effort to Develop Vaccines for COVID-19

There have been recent encouraging reports about the development of vaccines for COVID-19. Given the scale and effects of this pandemic on public health and economies worldwide, there has been an unprecedented approach across the globe, leading to the emergence of vaccine candidates many times faster than the normal process would allow. This review gives up-to-date information as of November 28, 2020, on the latest developments in this area and covers the plans to roll out the most promising vaccines across the entire world to halt the spread of this devastating virus.

COVID-19-associated acute respiratory distress syndrome (CARDS): Current knowledge on pathophysiology and ICU treatment - A narrative review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces coronavirus-19 disease (COVID-19) and is a major health concern. Following two SARS-CoV-2 pandemic “waves,” intensive care unit (ICU) specialists are treating a large number of COVID19-associated acute respiratory distress syndrome (ARDS) patients. From a pathophysiological perspective, prominent mechanisms of COVID19-associated ARDS (CARDS) include severe pulmonary infiltration/edema and inflammation leading to impaired alveolar homeostasis, alteration of pulmonary physiology resulting in pulmonary fibrosis, endothelial inflammation (endotheliitis), vascular thrombosis, and immune cell activation.

Although the syndrome ARDS serves as an umbrella term, distinct, i.e., CARDS-specific pathomechanisms and comorbidities can be noted (e.g., virus-induced endotheliitis associated with thromboembolism) and some aspects of CARDS can be considered ARDS “atypical.” Importantly, specific evidence-based medical interventions for CARDS (with the potential exception of corticosteroid use) are currently unavailable, limiting treatment efforts to mostly supportive ICU care.

In this article, we will discuss the underlying pulmonary pathophysiology and the clinical management of CARDS. In addition, we will outline current and potential future treatment approaches.