Glucocorticoids inhibit type I IFN beta signaling and the upregulation of CD73 in human lung

Steroids and Immunomodulatory Therapies for Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is characterized by a dysregulated immune response to infection or injury. This framework has driven long-standing interest in immunomodulatory therapies as treatments for ARDS. In this narrative review, we first define what constitutes a dysregulated immune response in ARDS. In this context, we describe the rationale and available evidence for immunomodulatory therapies studied in randomized controlled trials of ARDS patients to date. Finally, we address factors that have contributed to the failure to develop therapies in the past and highlight current and future developments designed to address them.

Infective endocarditis presentations during the COVID-19 pandemic: have they paid an untold toll?

Background: COVID-19 caused restrictions and re-allocation of medical resources among all healthcare services. During the peak of the pandemic, several unrelated-yet critical-conditions had silently taken their toll. Infective endocarditis (IE), owing to its non-specific clinical presentation, may have been largely mislabeled as COVID-19 in a number of cases. Results: This retrospective observational study reviewed all IE presentations at an IE unit in a university hospital during the peak of COVID-19. Patient characteristics, courses, and outcomes were compared with historical controls from our IE database published before the COVID era. We identified 30 IE cases [Group A] during the COVID-19 peak in our region (June 2021 to June 2022), with a 25% decrease compared to the usual annual rate. This is in contrast to the expected surge during the pandemic. Compared with group B (398 published IE cases from our database), group A had significantly longer symptoms-to-presentation intervals (60 [31-92] vs. 28 [14-72] days, p = 0.01). Male sex dominated both groups, but group A had significantly less pre-existing structural heart disease. Despite the more liberal use of empirical antibiotics in the COVID-era, group-A had lower rates of culture-negative IE. Compared to group B, group A demonstrated a better response to medical therapy, fewer arterial embolizations, fewer indications for surgery, and fewer overall complications, except for increased acute kidney injury. This can be explained by the abundant use of non-steroidal anti-inflammatory drugs. The data analysis strongly suggests that there might have been a natural selection or selection bias of IE patients with favorable profiles to survive the pandemic to the appropriate diagnosis. Conclusions: The diagnosis of IE and commencing the appropriate workup were significantly undermined during the COVID-19 pandemic. The inexplicable decline in IE referral rate and the favorable outcomes witnessed during the pandemic strongly suggest a referral bias and natural selection of those who survived the pandemic to the appropriate IE diagnosis.

Inhibition of the lysine demethylase LSD1 modulates the balance between inflammatory and antiviral responses against coronaviruses

Innate immune responses to coronavirus infections are highly cell specific. Tissue-resident macrophages, which are infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients but are inconsistently infected in vitro, exert critical but conflicting effects by secreting both antiviral type I interferons (IFNs) and tissue-damaging inflammatory cytokines. Steroids, the only class of host-targeting drugs approved for the treatment of coronavirus disease 2019 (COVID-19), indiscriminately suppress both responses, possibly impairing viral clearance. Here, we established in vitro cell culture systems that enabled us to separately investigate the cell-intrinsic and cell-extrinsic proinflammatory and antiviral activities of mouse macrophages infected with the prototypical murine coronavirus MHV-A59. We showed that the nuclear factor κB-dependent inflammatory response to viral infection was selectively inhibited by loss of the lysine demethylase LSD1, which was previously implicated in innate immune responses to cancer, with negligible effects on the antiviral IFN response. LSD1 ablation also enhanced an IFN-independent antiviral response, blocking viral egress through the lysosomal pathway. The macrophage-intrinsic antiviral and anti-inflammatory activity of Lsd1 inhibition was confirmed in vitro and in a humanized mouse model of SARS-CoV-2 infection. These results suggest that LSD1 controls innate immune responses against coronaviruses at multiple levels and provide a mechanistic rationale for potentially repurposing LSD1 inhibitors for COVID-19 treatment.

The influence of steroid type on outcomes in patients with acute respiratory distress syndrome

BACKGROUND

Recent systematic reviews and meta-analyses have suggested that low-dose steroids are effective in the treatment of acute respiratory distress syndrome (ARDS). Recent guidelines recommend the use of low-dose steroids instead of high-dose steroids. These systematic reviews were conducted based on the concept that the effect of steroids is constant regardless of their type. We discuss whether the type of steroid used influences the outcomes in patients with ARDS.

MAIN BODY

From a pharmacological standpoint, methylprednisolone has little activity as a mineralocorticoid and may cause pulmonary hypertension. The results of the rank probability of our previous network meta-analysis revealed that low-dose methylprednisolone might be an optimal treatment compared to using other types of steroids or no steroids in terms of ventilator-free days. Similarly, an analysis of individual data from four randomized controlled trials suggested that low-dose methylprednisolone was associated with decreased mortality in patients with ARDS. Dexamethasone has attracted the attention of clinicians as a novel adjunct therapy for ARDS.

CONCLUSION

Recent evidence has shown that low-dose methylprednisolone may be an effective treatment option for ARDS. The timing of initiation and duration of low-dose methylprednisolone therapy should be verified in future studies.

The value of Interferon β in multiple sclerosis and novel opportunities for its anti-viral activity: a narrative literature review

Interferon-beta (IFN-β) for Multiple Sclerosis (MS) is turning 30. The COVID-19 pandemic rejuvenated the interest in interferon biology in health and disease, opening translational opportunities beyond neuroinflammation. The antiviral properties of this molecule are in accord with the hypothesis of a viral etiology of MS, for which a credible culprit has been identified in the Epstein-Barr Virus. Likely, IFNs are crucial in the acute phase of SARS-CoV-2 infection, as demonstrated by inherited and acquired impairments of the interferon response that predispose to a severe COVID-19 course. Accordingly, IFN-β exerted protection against SARS-CoV-2 in people with MS (pwMS). In this viewpoint, we summarize the evidence on IFN-β mechanisms of action in MS with a focus on its antiviral properties, especially against EBV. We synopsize the role of IFNs in COVID-19 and the opportunities and challenges of IFN-β usage for this condition. Finally, we leverage the lessons learned in the pandemic to suggest a role of IFN-β in long-COVID-19 and in special MS subpopulations.

Genetic Determinants of the Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a life-threatening lung condition that arises from multiple causes, including sepsis, pneumonia, trauma, and severe coronavirus disease 2019 (COVID-19). Given the heterogeneity of causes and the lack of specific therapeutic options, it is crucial to understand the genetic and molecular mechanisms that underlie this condition. The identification of genetic risks and pharmacogenetic loci, which are involved in determining drug responses, could help enhance early patient diagnosis, assist in risk stratification of patients, and reveal novel targets for pharmacological interventions, including possibilities for drug repositioning. Here, we highlight the basis and importance of the most common genetic approaches to understanding the pathogenesis of ARDS and its critical triggers. We summarize the findings of screening common genetic variation via genome-wide association studies and analyses based on other approaches, such as polygenic risk scores, multi-trait analyses, or Mendelian randomization studies. We also provide an overview of results from rare genetic variation studies using Next-Generation Sequencing techniques and their links with inborn errors of immunity. Lastly, we discuss the genetic overlap between severe COVID-19 and ARDS by other causes.

Polymorphism in interferon alpha/beta receptor contributes to glucocorticoid response and outcome of ARDS and COVID-19

BACKGROUND

The use of glucocorticoids has given contradictory results for treating acute respiratory distress syndrome (ARDS). The use of intravenous Interferon beta (IFN β) for the treatment of ARDS was recently tested in a phase III ARDS trial (INTEREST), in which more than half of the patients simultaneously received glucocorticoids. Trial results showed deleterious effects of glucocorticoids when administered together with IFN β, and therefore, we aimed at finding the reason behind this.

METHODS

We first sequenced the genes encoding the IFN α/β receptor of the patients, who participated in the INTEREST study (ClinicalTrials.gov Identifier:  NCT02622724 , November 24, 2015) in which the patients were randomized to receive an intravenous injection of IFN β-1a (144 patients) or placebo (152 patients). Genetic background was analyzed against clinical outcome, concomitant medication, and pro-inflammatory cytokine levels. Thereafter, we tested the influence of the genetic background on IFN α/β receptor expression in lung organ cultures and whether, it has any effect on transcription factors STAT1 and STAT2 involved in IFN signaling.

RESULTS

We found a novel disease association of a SNP rs9984273, which is situated in the interferon α/β receptor subunit 2 (IFNAR2) gene in an area corresponding to a binding motif of the glucocorticoid receptor (GR). The minor allele of SNP rs9984273 associates with higher IFNAR expression, more rapid decrease of IFN γ and interleukin-6 (IL-6) levels and better outcome in IFN β treated patients with ARDS, while the major allele associates with a poor outcome especially under concomitant IFN β and glucocorticoid treatment. Moreover, the minor allele of rs9984273 associates with a less severe form of coronavirus diseases (COVID-19) according to the COVID-19 Host Genetics Initiative database.

CONCLUSIONS

The distribution of this SNP within clinical study arms may explain the contradictory results of multiple ARDS studies and outcomes in COVID-19 concerning type I IFN signaling and glucocorticoids.

CD73: Friend or Foe in Lung Injury

Ecto-5′-nucleotidase (CD73) plays a strategic role in calibrating the magnitude and chemical nature of purinergic signals that are delivered to immune cells. Its primary function is to convert extracellular ATP to adenosine in concert with ectonucleoside triphosphate diphosphohydrolase-1 (CD39) in normal tissues to limit an excessive immune response in many pathophysiological events, such as lung injury induced by a variety of contributing factors. Multiple lines of evidence suggest that the location of CD73, in proximity to adenosine receptor subtypes, indirectly determines its positive or negative effect in a variety of organs and tissues and that its action is affected by the transfer of nucleoside to subtype-specific adenosine receptors. Nonetheless, the bidirectional nature of CD73 as an emerging immune checkpoint in the pathogenesis of lung injury is still unknown. In this review, we explore the relationship between CD73 and the onset and progression of lung injury, highlighting the potential value of this molecule as a drug target for the treatment of pulmonary disease.

Decreased circulating CD73 and adenosine deaminase are associated with disease severity in hospitalized patients with COVID-19

OBJECTIVE

SARS-CoV-2 infection has been shown to result in increased circulating levels of adenosine triphosphate and adenosine diphosphate and decreased levels of adenosine, which has important anti-inflammatory activity. The goal of this pilot project was to assess the levels of soluble CD73 and soluble Adenosine Deaminase (ADA) in hospitalized patients with COVID-19 and determine if levels of these molecules are associated with disease severity.

METHODS

Plasma from 28 PCR-confirmed hospitalized COVID-19 patients who had varied disease severity based on WHO classification (6 mild/moderate, 10 severe, 12 critical) had concentrations of both soluble CD73 and ADA determined by ELISA. These concentrations were compared to healthy control plasma that is commercially available and was biobanked prior to the start of the pandemic. Additionally, outcomes such as WHO ordinal scale for disease severity, ICU admission, needed for invasive ventilation, hospital length of stay, and development of thrombosis during admission were used as markers of disease severity.

RESULTS

Our results show that both CD73 and ADA are decreased during SARS-CoV-2 infection. The level of circulating CD73 is directly correlated to the severity of the disease defined by the need for ICU admission, invasive ventilation, and hospital length of stay. Low level of CD73 is also associated with clinical thrombosis, a severe complication of SARS-CoV-2 infection.

CONCLUSION

Our study indicates that adenosine metabolism is down-regulated in patients with COVID-19 and associated with severe infection. Further large-scale studies are warranted to investigate the role of the adenosinergic anti-inflammatory CD73/ADA axis in protection against COVID-19.

Infective Endocarditis Revealed after Resolution of COVID-19 Infection

A 34-year-old previously healthy Japanese woman was diagnosed with COVID-19 and treated with remdesivir and dexamethasone. She was discharge but returned the next day due to acute myocardial infarction. Conservative treatment was selected because of an embolic occlusion in the distal portion. Contrast-enhanced computed tomography and brain magnetic resonance imaging revealed a right renal infarction and multiple cerebral embolisms, respectively; she had a fever of 38.9°C that night. Blood culture was positive for methicillin-susceptible Staphylococcus aureus. Transthoracic echocardiography revealed an 11-mm vegetation on the posterior mitral valve leaflet. Native mitral valve infective endocarditis causing multiple embolizations was diagnosed. She underwent surgical mitral valve replacement.

Cytokines and microRNAs in SARS-CoV-2: What do we know?

The coronavirus disease 2019 (COVID-19) pandemic constitutes a global health emergency. Currently, there are no completely effective therapeutic medications for the management of this outbreak. The cytokine storm is a hyperinflammatory medical condition due to excessive and uncontrolled release of pro-inflammatory cytokines in patients suffering from severe COVID-19, leading to the development of acute respiratory distress syndrome (ARDS) and multiple organ dysfunction syndrome (MODS) and even mortality. Understanding the pathophysiology of COVID-19 can be helpful for the treatment of patients. Evidence suggests that the levels of tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1 and IL-6 are dramatically different between mild and severe patients, so they may be important contributors to the cytokine storm. Several serum markers can be predictors for the cytokine storm. This review discusses the cytokines involved in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, focusing on interferons (IFNs) and ILs, and whether they can be used in COVID-19 treatment. Moreover, we highlight several microRNAs that are involved in these cytokines and their role in the cytokine storm caused by COVID-19.

Gene Cloning, Tissue Expression Profiles and Antiviral Activities of Interferon-β from Two Chinese Miniature Pig Breeds

The porcine interferon (PoIFN) complex represents an ideal model for studying IFN evolution which has resulted from viral pressure during domestication. Bama and Banna miniature pigs are the two Chinese miniature pig breeds that have been developed as laboratory animal models for studying virus infection, pathogenesis, and vaccine evaluation. However, the PoIFN complex of such miniature pig breeds remains to be studied. In the present study, we cloned PoIFN-β genes from Bama and Banna miniature pigs, detected their PoIFN-β tissue expression profiles, prepared recombinant PoIFN-β (rPoIFN-β) using the E. coli expression system, and measured their antiviral activities against three different pig viruses. At the amino acid sequence level, PoIFN-βs of the two miniature pig breeds were identical, which shared 100% identity with that of Congjiang Xiang pigs, 99.4–100% identity with that of domestic pigs, and 99.5% identity with that of three species of African wild boars. The tissue expression profiles of PoIFN-β mRNA differed not only between the two miniature pig breeds but between miniature pigs and domestic pigs as well. The four promoter domains of PoIFN-β of the two miniature pig breeds were identical with that of humans, domestic pigs, and three species of African wild boars. The recombinant PoIFN-β prepared from the two miniature pig breeds showed dose-dependent pre-infection and post-infection antiviral activities against vesicular stomatitis virus, porcine respiratory and reproductive syndrome virus, and pig pseudorabies virus. This study provided evidence for the high sequence conservation of PoIFN-β genes within the Suidae family with different tissue expression profiles and antiviral activities.

Immunomodulatory agents for COVID-19 treatment: possible mechanism of action and immunopathology features

The novel coronavirus pandemic has emerged as one of the significant medical-health challenges of the current century. The World Health Organization has named this new virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first detection of SARS-CoV-2 in November 2019 in Wuhan, China, physicians, researchers, and others have made it their top priority to find drugs and cures that can effectively treat patients and reduce mortality rates. The symptoms of Coronavirus Disease 2019 (COVID-19) include fever, dry cough, body aches, and anosmia. Various therapeutic compounds have been investigated and applied to mitigate the symptoms in COVID-19 patients and cure the disease. Degenerative virus analyses of the infection incidence and COVID-19 have demonstrated that SARS-CoV-2 penetrates the pulmonary alveoli's endothelial cells through Angiotensin-Converting Enzyme 2 (ACE2) receptors on the membrane, stimulates various signaling pathways and causes excessive secretion of cytokines. The continuous triggering of the innate and acquired immune system, as well as the overproduction of pro-inflammatory factors, cause a severe condition in the COVID-19 patients, which is called "cytokine storm". It can lead to acute respiratory distress syndrome (ARDS) in critical patients. Severe and critical COVID-19 cases demand oxygen therapy and mechanical ventilator support. Various drugs, including immunomodulatory and immunosuppressive agents (e.g., monoclonal antibodies (mAbs) and interleukin antagonists) have been utilized in clinical trials. However, the studies and clinical trials have documented diverging findings, which seem to be due to the differences in these drugs' possible mechanisms of action. These drugs' mechanism of action generally includes suppressing or modulating the immune system, preventing the development of cytokine storm via various signaling pathways, and enhancing the blood vessels' diameter in the lungs. In this review article, multiple medications from different drug families are discussed, and their possible mechanisms of action are also described.

Induction of CD73 prevents death after emergency open aortic surgery for a ruptured abdominal aortic aneurysm: a randomized, double-blind, placebo-controlled study

Mortality remains high after emergency open surgery for a ruptured abdominal aortic aneurysm (RAAA). The aim of the present study was to assess, if intravenous (IV) Interferon (IFN) beta-1a improve survival after surgery by up-regulating Cluster of differentiation (CD73). This is a multi-center phase II double-blind, 2:1 randomized, parallel group comparison of the efficacy and safety of IV IFN beta-1a vs. placebo for the prevention of death after open surgery for an infra-renal RAAA. All study patients presented a confirmed infra-renal RAAA, survived the primary emergency surgery and were treated with IFN beta-1a (10 μg) or matching placebo for 6 days after surgery. Major exclusion criteria included fatal hemorrhagic shock, chronic renal replacement therapy, diagnosed liver cirrhosis, severe congestive heart failure, advanced malignant disease, primary attempt of endovascular aortic repair (EVAR), and per-operative suprarenal clamping over 30 min. Main outcome measure was all-cause mortality at day 30 (D30) from initial emergency aortic reconstruction. The study was pre-maturely stopped due to a reported drug-drug interaction and was left under-powered. Out of 40 randomized patients 38 were included in the outcome analyses (27 IFN beta-1a and 11 placebo). There was no statistically significant difference between treatment groups at baseline except more open-abdomen and intestinal ischemia was present in the IFN beta-1a arm. D30 all-cause mortality was 22.2% (6/27) in the IFN beta-1a arm and 18.2% (2/11) in the placebo arm (OR 1.30; 95% CI 0.21-8.19). The most common adverse event relating to the IFN beta-1a was pyrexia (20.7% in the IFN beta-1a arm vs. 9.1% in the placebo arm). Patients with high level of serum CD73 associated with survival (P = 0.001) whereas the use of glucocorticoids and the presence of IFN beta-1a neutralizing antibodies associated with a poor CD73 response and survival. The initial aim of the trial, if postoperative INF beta-1a treatment results on better RAAA survival, could not be demonstrated. Nonetheless the anticipated target mechanism up-regulation of CD73 was associated with 100% survival. According to present results the INF beta-1a induced up-regulation of serum CD73 was blocked with both use of glucocorticoids and serum IFN beta-1a neutralizing antibodies. The study was pre-maturely stopped due to interim analysis after a study concerning the use if IV IFN beta-1a in ARDS suggested that the concomitant use of glucocorticoids and IFN beta-1a block the CD73 induction. Trial registration: ClinicalTrials.gov NCT03119701. Registered 19/04/2017 (retrospectively registered).

Exploiting natural antiviral immunity for the control of pandemics: Lessons from Covid-19

The outbreak of coronavirus disease 2019 (COVID-19), triggered by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the disruptive global consequences in terms of mortality and social and economic crises, have taught lessons that may help define strategies to better face future pandemics. Innate and intrinsic immunity form the front-line natural antiviral defense. They involve both tissue-resident and circulating cells, which can produce anti-viral molecules shortly after viral infection. Prototypes of these factors are type I interferons (IFN), antiviral cytokines with a long record of clinical use. During the last two years, there has been an impressive progress in understanding the mechanisms of both SARS-CoV-2 infection and the cellular and soluble antiviral responses occurring early after viral exposure. However, this information was not sufficiently translated into therapeutic approaches. Insufficient type I IFN activity probably accounts for disease progression in many patients. This results from both the multiple interfering mechanisms developed by SARS-CoV-2 to decrease type I IFN response and various pre-existing human deficits of type I IFN activity, inherited or auto-immune. Emerging data suggest that IFN-I-mediated boosting of patients' immunity, achieved directly through the exogenous administration of IFN-β early post viral infection, or indirectly following inoculation of heterologous vaccines (e.g., Bacillus Calmette Guerin), might play a role against SARS-CoV-2. We review how recent insights on the viral and human determinants of critical COVID-19 pneumonia can foster clinical studies of IFN therapy. We also discuss how early therapeutic use of IFN-β and prophylactic campaigns with live attenuated vaccines might prevent a first wave of new pandemic viruses.

Dexamethasone Transiently Enhances Transgene Expression in the Liver When Administered at Late-Phase Post Long-Term Adeno-Associated Virus Transduction

Glucocorticoids have anti-inflammatory and immunosuppressive functions and have commonly been used for preventing liver toxicity after the systemic application of a high dose of adeno-associated virus (AAV) vector for gene therapy. Clinical studies have reported that glucocorticoids have rescued factor IX (FIX) expression in patients with hemophilia B who showed a reduced FIX expression at 6 to 10 weeks post-AAV vector administration. In this study, we explored whether glucocorticoids could affect transgene expression in AAV targeted livers in animal models. When dexamethasone was applied before AAV9/FIX vector administration in the wild-type C57BL/6 mice, FIX expression was much higher than that of the control mice at any time point. More importantly, FIX expression transiently increased after dexamethasone was administered at week 6 or later post-AAV injection regardless of the various dexamethasone treatments applied. The transient enhancement in transgene expression was observed once there were one to several consecutive dexamethasone treatments completed. A similar result was also achieved in other wild-type BALB/c and hemophilia B mice that were treated with AAV9/FIX and dexamethasone. This mechanism study demonstrated that the administration of dexamethasone did not change either AAV genome copy number or transgene expression at the transcription level but transiently decreased interferon beta (IFN-β) and tumor necrosis factor alpha (TNF-α) expression in the livers of mice at a later time after AAV injection. Next, we studied the effect of dexamethasone on late transgene expression in hemophilia B dogs. Dexamethasone was administered 1 year after AAV9/FIX injection. Inconsistent with the results in mice, no significant change of FIX expression was observed in hemophilia B dogs. In summary, the results from this study indicate that dexamethasone may have various effects on transgene expression in AAV-transduced livers in different species, which provides valuable information about the rational application of dexamethasone in future clinical studies.

COVID-19, corticosteroids and public health: a reappraisal

OBJECTIVES

To assess whether regulatory guidance on the use of dexamethasone in hospitalised COVID-19 patients is applicable to the larger population of COVID-19 cases. The surge in worldwide demand for dexamethasone suggests that the guidance, although correct, has not emphasised the danger of its wider use.

STUDY DESIGN

Data from the Randomised Evaluation of COVID-19 Therapy (RECOVERY) trial and the World Health Organisation (WHO) prospective meta-analysis have been deconstructed and analysed.

METHODS

To provide context, relevant publications were identified in PubMed using the following keywords: COVID-19, RECOVERY trial, WHO meta-analysis, variants, immunity, public health.

RESULTS

The WHO guidance 'Corticosteroids for COVID-19' was based on their prospective meta-analysis. This meta-analysis was weighted by data from the RECOVERY trial.

CONCLUSIONS

In terms of COVID-19, dexamethasone has value in a narrow indication, namely, in hospitalised patients requiring respiratory support. The media blitz likely resulted in the wider use of dexamethasone in outpatients and as a preventive medication. This is reflected in the surge in worldwide demand for dexamethasone. We ask whether the use of steroids, beyond regulatory indications, may be responsible for the recent increase in mortality and especially the emergence of mucormycosis? From the public health standpoint, the current guidance for use of dexamethasone in COVID-19 could benefit from clarification and the addition of a cautionary note.

SARS-CoV-2: Insight in genome structure, pathogenesis and viral receptor binding analysis - An updated review

The novel coronavirus disease (COVID-19) a global pandemic outbreak is an emerging new virus accountable for respiratory illness caused by SARS-CoV-2, originated in Wuhan city, Hubei province China, urgently calls to adopt prevention and intervention strategies. Several viral epidemics such as severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002 to 2003 and H1N1 influenza in 2009 were reported since last two decades. Moreover, the Saudi Arabia was the epicenter for Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012. The CoVs are large family with single-stranded RNA viruses (+ssRNA). Genome sequence of 2019-nCoV, shows relatively different homology from other coronavirus subtypes, categorized in betacoronavirus and possibly found from strain of bats. The COVID-19 composed of exposed densely glycosylated spike protein (S) determines virus binding and infiltrate into host cells as well as initiate protective host immune response. Recently published reviews on the emerging SARS-CoV-2 have mainly focused on its structure, development of the outbreak, relevant precautions and management trials. Currently, there is an urgency of pharmacological intervention to combat this deadly infectious disease. Elucidation of molecular mechanism of COVID-19 becomes necessary. Based on the current literature and understanding, the aim of this review is to provide current genome structure, etiology, clinical prognosis as well as to explore the viral receptor binding together functional insight of SARS-CoV-2 infection (COVID-19) with treatment and preventive measures.

Regulation of Tissue Immune Responses by Local Glucocorticoids at Epithelial Barriers and Their Impact on Interorgan Crosstalk

The anti-inflammatory role of extra-adrenal glucocorticoid (GC) synthesis at epithelial barriers is of increasing interest with regard to the search for alternatives to synthetic corticosteroids in the therapy of inflammatory disorders. Despite being very effective in many situations the use of synthetic corticosteroids is often controversial, as exemplified in the treatment of influenza patients and only recently in the current COVID-19 pandemic. Exploring the regulatory capacity of locally produced GCs in balancing immune responses in barrier tissues and in pathogenic disorders that lead to symptoms in multiple organs, could provide new perspectives for drug development. Intestine, skin and lung represent the first contact zones between potentially harmful pathogens or substances and the body, and are therefore important sites of immunoregulatory mechanisms. Here, we review the role of locally produced GCs in the regulation of type 2 immune responses, like asthma, atopic dermatitis and ulcerative colitis, as well as type 1 and type 3 infectious, inflammatory and autoimmune diseases, like influenza infection, psoriasis and Crohn’s disease. In particular, we focus on the role of locally produced GCs in the interorgan communication, referred to as gut-skin axis, gut-lung axis or lung-skin axis, all of which are interconnected in the pathogenic crosstalk atopic march.

Clinical evidence of an interferon-glucocorticoid therapeutic synergy in COVID-19

Synthetic glucocorticoid dexamethasone is the first trial-proven drug that reduces COVID-19 mortality by suppressing immune system. In contrast, interferons are a crucial component of host antiviral immunity and can be directly suppressed by glucocorticoids. To investigate whether therapeutic interferons can compensate glucocorticoids-induced loss of antiviral immunity, we retrospectively analyzed a cohort of 387 PCR-confirmed COVID-19 patients with quasi-random exposure to interferons and conditional exposure to glucocorticoids. Among patients receiving glucocorticoids, early interferon therapy was associated with earlier hospital discharge (adjusted HR 1.68, 95% CI 1.19-2.37) and symptom relief (adjusted HR 1.48, 95% CI 1.06-2.08), while these associations were insignificant among glucocorticoids nonusers. Early interferon therapy was also associated with lower prevalence of prolonged viral shedding (adjusted OR 0.24, 95% CI 0.10-0.57) only among glucocorticoids users. Additionally, these associations were glucocorticoid cumulative dose- and timing-dependent. These findings reveal potential therapeutic synergy between interferons and glucocorticoids in COVID-19 that warrants further investigation.

Interferon-beta offers promising avenues to COVID-19 treatment: a systematic review and meta-analysis of clinical trial studies

Severe acute respiratory syndrome coronavirus 2 principally weakens the hosts’ innate immune system by impairing the interferon function and production. Type I interferons (IFNs) especially IFN-β are best known for their antiviral activities. IFNs accompanied by the standard care protocols have opened up unique opportunities for treating the coronavirus disease 2019 (COVID-19). The databases including PubMed, SCOPUS, EMBASE, and Google Scholar were searched up to October 30, 2020. The primary and secondary outcomes were considered discharge and mortality, respectively. The abovementioned outcomes of standard care protocol were compared with the standard care plus IFN-β in the confirmed COVID-19 patients. Out of 356 records identified, 12 randomized clinical trial studies were selected for full-text screening. Finally, 5 papers were included in the systematic review and 3 papers in the meta-analysis. The average mortality rate was reported as 6.195% and 18.02% in intervention and control groups, respectively. Likewise, the median days of hospitalization were lower in the intervention group (9 days) than the control group (12.25 days). According to meta-analysis, IFN-β was found to increase the overall discharge rate (RR = 3.05; 95% CI: 1.09–5.01). Our findings revealed that early administration of IFN-β in combination with antiviral drugs is a promising therapeutic strategy against COVID-19.

Repurposed Antiviral Drugs for Covid-19 - Interim WHO Solidarity Trial Results

BACKGROUND

World Health Organization expert groups recommended mortality trials of four repurposed antiviral drugs - remdesivir, hydroxychloroquine, lopinavir, and interferon beta-1a - in patients hospitalized with coronavirus disease 2019 (Covid-19).

METHODS

We randomly assigned inpatients with Covid-19 equally between one of the trial drug regimens that was locally available and open control (up to five options, four active and the local standard of care). The intention-to-treat primary analyses examined in-hospital mortality in the four pairwise comparisons of each trial drug and its control (drug available but patient assigned to the same care without that drug). Rate ratios for death were calculated with stratification according to age and status regarding mechanical ventilation at trial entry.

RESULTS

At 405 hospitals in 30 countries, 11,330 adults underwent randomization; 2750 were assigned to receive remdesivir, 954 to hydroxychloroquine, 1411 to lopinavir (without interferon), 2063 to interferon (including 651 to interferon plus lopinavir), and 4088 to no trial drug. Adherence was 94 to 96% midway through treatment, with 2 to 6% crossover. In total, 1253 deaths were reported (median day of death, day 8; interquartile range, 4 to 14). The Kaplan-Meier 28-day mortality was 11.8% (39.0% if the patient was already receiving ventilation at randomization and 9.5% otherwise). Death occurred in 301 of 2743 patients receiving remdesivir and in 303 of 2708 receiving its control (rate ratio, 0.95; 95% confidence interval [CI], 0.81 to 1.11; P = 0.50), in 104 of 947 patients receiving hydroxychloroquine and in 84 of 906 receiving its control (rate ratio, 1.19; 95% CI, 0.89 to 1.59; P = 0.23), in 148 of 1399 patients receiving lopinavir and in 146 of 1372 receiving its control (rate ratio, 1.00; 95% CI, 0.79 to 1.25; P = 0.97), and in 243 of 2050 patients receiving interferon and in 216 of 2050 receiving its control (rate ratio, 1.16; 95% CI, 0.96 to 1.39; P = 0.11). No drug definitely reduced mortality, overall or in any subgroup, or reduced initiation of ventilation or hospitalization duration.

CONCLUSIONS

These remdesivir, hydroxychloroquine, lopinavir, and interferon regimens had little or no effect on hospitalized patients with Covid-19, as indicated by overall mortality, initiation of ventilation, and duration of hospital stay. (Funded by the World Health Organization; ISRCTN Registry number, ISRCTN83971151; ClinicalTrials.gov number, NCT04315948.).

Repurposed Antiviral Drugs for Covid-19 - Interim WHO Solidarity Trial Results

BACKGROUND

World Health Organization expert groups recommended mortality trials of four repurposed antiviral drugs - remdesivir, hydroxychloroquine, lopinavir, and interferon beta-1a - in patients hospitalized with coronavirus disease 2019 (Covid-19).

METHODS

We randomly assigned inpatients with Covid-19 equally between one of the trial drug regimens that was locally available and open control (up to five options, four active and the local standard of care). The intention-to-treat primary analyses examined in-hospital mortality in the four pairwise comparisons of each trial drug and its control (drug available but patient assigned to the same care without that drug). Rate ratios for death were calculated with stratification according to age and status regarding mechanical ventilation at trial entry.

RESULTS

At 405 hospitals in 30 countries, 11,330 adults underwent randomization; 2750 were assigned to receive remdesivir, 954 to hydroxychloroquine, 1411 to lopinavir (without interferon), 2063 to interferon (including 651 to interferon plus lopinavir), and 4088 to no trial drug. Adherence was 94 to 96% midway through treatment, with 2 to 6% crossover. In total, 1253 deaths were reported (median day of death, day 8; interquartile range, 4 to 14). The Kaplan-Meier 28-day mortality was 11.8% (39.0% if the patient was already receiving ventilation at randomization and 9.5% otherwise). Death occurred in 301 of 2743 patients receiving remdesivir and in 303 of 2708 receiving its control (rate ratio, 0.95; 95% confidence interval [CI], 0.81 to 1.11; P = 0.50), in 104 of 947 patients receiving hydroxychloroquine and in 84 of 906 receiving its control (rate ratio, 1.19; 95% CI, 0.89 to 1.59; P = 0.23), in 148 of 1399 patients receiving lopinavir and in 146 of 1372 receiving its control (rate ratio, 1.00; 95% CI, 0.79 to 1.25; P = 0.97), and in 243 of 2050 patients receiving interferon and in 216 of 2050 receiving its control (rate ratio, 1.16; 95% CI, 0.96 to 1.39; P = 0.11). No drug definitely reduced mortality, overall or in any subgroup, or reduced initiation of ventilation or hospitalization duration.

CONCLUSIONS

These remdesivir, hydroxychloroquine, lopinavir, and interferon regimens had little or no effect on hospitalized patients with Covid-19, as indicated by overall mortality, initiation of ventilation, and duration of hospital stay. (Funded by the World Health Organization; ISRCTN Registry number, ISRCTN83971151; ClinicalTrials.gov number, NCT04315948.).

Interferon Beta-1b and Lopinavir-Ritonavir for Middle East Respiratory Syndrome

BACKGROUND

Whether combined treatment with recombinant interferon beta-1b and lopinavir-ritonavir reduces mortality among patients hospitalized with Middle East respiratory syndrome (MERS) is unclear.

METHODS

We conducted a randomized, adaptive, double-blind, placebo-controlled trial that enrolled patients at nine sites in Saudi Arabia. Hospitalized adults with laboratory-confirmed MERS were randomly assigned to receive recombinant interferon beta-1b plus lopinavir-ritonavir (intervention) or placebo for 14 days. The primary outcome was 90-day all-cause mortality, with a one-sided P-value threshold of 0.025. Prespecified subgroup analyses and safety analyses were conducted. Because of the pandemic of coronavirus disease 2019, the data and safety monitoring board requested an unplanned interim analysis and subsequently recommended the termination of enrollment and the reporting of the results.

RESULTS

A total of 95 patients were enrolled; 43 patients were assigned to the intervention group and 52 to the placebo group. A total of 12 patients (28%) in the intervention group and 23 (44%) in the placebo group died by day 90. The analysis of the primary outcome, with accounting for the adaptive design, yielded a risk difference of -19 percentage points (upper boundary of the 97.5% confidence interval [CI], -3; one-sided P = 0.024). In a prespecified subgroup analysis, treatment within 7 days after symptom onset led to lower 90-day mortality than use of placebo (relative risk, 0.19; 95% CI, 0.05 to 0.75), whereas later treatment did not. Serious adverse events occurred in 4 patients (9%) in the intervention group and in 10 (19%) in the placebo group.

CONCLUSIONS

A combination of recombinant interferon beta-1b and lopinavir-ritonavir led to lower mortality than placebo among patients who had been hospitalized with laboratory-confirmed MERS. The effect was greatest when treatment was started within 7 days after symptom onset. (Funded by the King Abdullah International Medical Research Center; MIRACLE ClinicalTrials.gov number, NCT02845843.).