Efficacy and safety of IL-6 inhibitors in patients with COVID-19 pneumonia: a systematic review and meta-analysis of multicentre, randomized trials

Effects of sEH inhibition on the eicosanoid and cytokine storms in SARS-CoV-2-infected mice

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection involves an initial viral infection phase followed by a host-response phase that includes an eicosanoid and cytokine storm, lung inflammation and respiratory failure. While vaccination and early anti-viral therapies are effective in preventing or limiting the pathogenic host response, this latter phase is poorly understood with no highly effective treatment options. Inhibitors of soluble epoxide hydrolase (sEH) increase levels of anti-inflammatory molecules called epoxyeicosatrienoic acids (EETs). This study aimed to investigate the impact of sEH inhibition on the host response to SARS-CoV-2 infection in a mouse model with human angiotensin-converting enzyme 2 (ACE2) expression. Mice were infected with SARS-CoV-2 and treated with either vehicle or the sEH inhibitor 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU). At day 5 post-infection, SARS-CoV-2 induced weight loss, clinical signs, a cytokine storm, an eicosanoid storm, and severe lung inflammation with ~50% mortality on days 6-8 post-infection. SARS-CoV-2 infection induced lung expression of phospholipase A2 (PLA2), cyclooxygenase (COX) and lipoxygenase (LOX) pathway genes, while suppressing expression of most cytochrome P450 genes. Treatment with the sEH inhibitor TPPU delayed weight loss but did not alter clinical signs, lung cytokine expression or overall survival of infected mice. Interestingly, TPPU treatment significantly reversed the eicosanoid storm and attenuated viral-induced elevation of 39 fatty acids and oxylipins from COX, LOX and P450 pathways, which suggests the effects at the level of PLA2 activation. The suppression of the eicosanoid storm by TPPU without corresponding changes in lung cytokines, lung inflammation or mortality reveals a surprising dissociation between systemic oxylipin and cytokine signaling pathways during SARS-CoV-2 infection and suggests that the cytokine storm is primarily responsible for morbidity and mortality in this animal model.

Therapeutic Impact of Tocilizumab in the Setting of Severe COVID-19; an Updated and Comprehensive Review on Current Evidence

Introduction

The COVID-19 pandemic caused by SARS-CoV-2 has been the major health concern in 2019 globally. Considering the severity and phase of the disease, various pharmacotherapy schedules were proposed. Here, we set out to provide close-up insights on the clinical utility of Tocilizumab (TCZ), a biologic monoclonal antibody in this regard.

Methods

In this comprehensive review, various databases, including Scopus, PubMed Central, Medline, Embase, Google Scholar, and preprint publishers (med/bioRxiv) were searched until January 30, 2024, according to the keywords and search criteria.

Results

Besides the pros and cons, compelling evidence purported the safety and efficacy of TCZ and indicated that it exhibits great potential to reduce short-term and all-cause (28-30-day) mortality. TCZ significantly drops the adverse events if administered in the right time course (in the inflammatory phase) during critical/severe COVID-19 pneumonia. Despite contradictory results, the benefits of TCZ appear significant, especially in combination with add-on therapies, such as corticosteroids. Although the safety of TCZ is acceptable, solid data is lacking as to its benefits during pregnancy. There are limited data on TCZ combination therapies, such as hemoperfusion, intravenous immunoglobulin (IVIG), simple O2 therapy, vasopressor support, convalescent plasma therapy, and even in vaccinated patients and COVID-19 reinfection, especially in elderly persons. In addition, the impact of TCZ therapy on the long-lasting COVID-19 is unclear.

Conclusion

Personalized medicine based on individual characteristics and pertinent clinical conditions must be considered in the clinicians' decision-making policy. Finally, to mitigate the risk-to-benefit ratio of TCZ, a treatment algorithm, based on available literature and updated national institute of health (NIH) and Infectious Diseases Society of America (IDSA) guidelines, is also proposed.

Interventions reducing mortality in COVID-19 patients: a systematic review of randomized evidence

INTRODUCTION

COVID-19 pandemic changed the way medical research is published, possibly forever. As the need for rapidity led to the rise of preprint servers, the undeniable drop in the overall quality of scientific publications requires an in-depth review of all available evidence. The present manuscript aims to identify and summarize all treatments which have been reported to reduce mortality in randomized trials in hospitalized COVID-19 patients.

EVIDENCE ACQUISITION

Independent investigators searched MEDLINE/PubMed, Scopus, and Embase databases to identify all randomized trials of any intervention influencing mortality in hospitalized COVID-19 patients up to August 18th, 2022. Articles were selected only when they fulfilled all the following: randomized trial design; dealing with any kind of interventions in adult hospitalized COVID-19 patients; and statistically significant reduction in mortality.

EVIDENCE SYNTHESIS

We identified 28 interventions (42 manuscripts) reducing mortality in hospitalized COVID-19 patients. About 60% of the studies (26/42) were multicentric, for a total of 1140 centers involved worldwide. Several of these studies were published in high-ranked, peer-reviewed journals. Interventions with randomized evidence of mortality reduction in hospitalized COVID-19 patients belonged to 5 domains: corticosteroids, immunomodulators, antimicrobials, supportive therapies, and other drugs.

CONCLUSIONS

Many interventions have the potential to reduce mortality in COVID-19 hospitalized patients. The correct treatment of future pandemics relies on large, multicentric randomized clinical trials for further evaluation of these promising strategies.

Nebulized Furosemide for Pulmonary Inflammation in Intubated Patients With COVID-19: A Phase 2 Randomized Controlled Double-Blind Study

OBJECTIVES

Respiratory failure secondary to COVID-19 is associated with morbidity and mortality. Current anti-inflammatory therapies are effective but are given systemically and have significant side effects. Furosemide has anti-inflammatory properties, can be administered by inhalation, and is inexpensive. We investigated the efficacy of nebulized furosemide as an adjunctive therapy for COVID-19 respiratory failure.

DESIGN

A double-blind, randomized, placebo-controlled trial.

SETTING

Multicenter ICU study.

PATIENTS

Adults requiring invasive mechanical ventilation secondary to COVID-19.

INTERVENTION

Patients were randomized within 48 hours of intubation to receive inhaled furosemide or placebo until day 28, death, or liberation from mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

The study was stopped early due to waning incidence of COVID-19; 39 patients were available for analysis with mean ± sd age of 70.5 (10.8) years, Acute Physiology and Chronic Health Evaluation II 26.1 (7.8) and Fio2 60.0% (21.9). Baseline characteristics were similar between the groups. For the primary outcome of change in Pao2/Fio2 ratio between day 1 and day 6, it was +31.4 (83.5) in the furosemide arm versus +20.1 (92.8) in the control (p = 0.58). For secondary outcomes, furosemide versus control: 60-day mortality was 48% versus 71% (p = 0.20), hospital stay was 25.6 (21.9) versus 27.4 (25.0) days, p = 0.94 and VFD was 6.0 (9.1) versus 3.1 (7.1), p value of equals to 0.28. A post hoc analysis of the hierarchical composite outcome, alive and ventilator-free favored furosemide. There were no adverse events.

CONCLUSIONS

In this trial of inhaled furosemide for COVID-19 respiratory failure, differences in Pao2/Fio2 ratio to day 6 and other clinical outcomes were not significantly different, although the trial was underpowered due to early termination. Given the favorable profile of inhaled furosemide, further study is warranted in disease states where acute pulmonary inflammation contributes to the underlying pathophysiology.

Suppressed transcript diversity and immune response in COVID-19 ICU patients: a longitudinal study

Understanding the dynamic changes in gene expression during Acute Respiratory Distress Syndrome (ARDS) progression in post-acute infection patients is crucial for unraveling the underlying mechanisms. Study investigates the longitudinal changes in gene/transcript expression patterns in hospital-admitted severe COVID-19 patients with ARDS post-acute SARS-CoV-2 infection. Blood samples were collected at three time points and patients were stratified into severe and mild ARDS, based on their oxygenation saturation (SpO2/FiO2) kinetics over 7 d. Decline in transcript diversity was observed over time, particularly in patients with higher severity, indicating dysregulated transcriptional landscape. Comparing gene/transcript-level analyses highlighted a rather limited overlap. With disease progression, a transition towards an inflammatory state was evident. Strong association was found between antibody response and disease severity, characterized by decreased antibody response and activated B cell population in severe cases. Bayesian network analysis identified various factors associated with disease progression and severity, viz. humoral response, TLR signaling, inflammatory response, interferon response, and effector T cell abundance. The findings highlight dynamic gene/transcript expression changes during ARDS progression, impact on tissue oxygenation and elucidate disease pathogenesis.

Differential Roles of Interleukin-6 in Severe Acute Respiratory Syndrome-Coronavirus-2 Infection and Cardiometabolic Diseases

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection can lead to a cytokine storm, unleashed in part by pyroptosis of virus-infected macrophages and monocytes. Interleukin-6 (IL-6) has emerged as a key participant in this ominous complication of COVID-19. IL-6 antagonists have improved outcomes in patients with COVID-19 in some, but not all, studies. IL-6 signaling involves at least 3 distinct pathways, including classic-signaling, trans-signaling, and trans-presentation depending on the localization of IL-6 receptor and its binding partner glycoprotein gp130. IL-6 has become a therapeutic target in COVID-19, cardiovascular diseases, and other inflammatory conditions. However, the efficacy of inhibition of IL-6 signaling in metabolic diseases, such as obesity and diabetes, may depend in part on cell type-dependent actions of IL-6 in controlling lipid metabolism, glucose uptake, and insulin sensitivity owing to complexities that remain to be elucidated. The present review sought to summarize and discuss the current understanding of how and whether targeting IL-6 signaling ameliorates outcomes following SARS-CoV-2 infection and associated clinical complications, focusing predominantly on metabolic and cardiovascular diseases.

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.

Management of Severe and Critical COVID-19 Infection with Immunotherapies

Following the reduction in mortality demonstrated by dexamethasone treatment in severe COVID-19, many targeted immunotherapies have been investigated. Thus far, inhibition of IL-6 and JAK pathways have the most robust data and have been granted Emergency Use Authorization for treatment of severe disease. However, it must be noted that critically ill patients comprised a relatively small proportion of most of the trials of COVID-19 therapeutics, despite bearing a disproportionate burden of morbidity and mortality. Furthermore, the rapidity and fluidity with which clinical trials have been conducted in the pandemic setting have contributed to difficulty in extrapolating available trial data to critically ill patients. The exclusion of many patients requiring invasive mechanical ventilation, preponderance of ordinal scale based endpoints, and frequent lack of blinding are particular challenges. More data is needed to identify beneficial treatments in the complex milieu of critical illness from COVID-19 infection.

Clinical efficacy and safety of interleukin-6 receptor antagonists (tocilizumab and sarilumab) in patients with COVID-19: a systematic review and meta-analysis

This study investigated the efficacy and safety of interleukin-6 (IL-6) receptor antagonists with standard care treatment in patients with coronavirus disease 2019 (COVID-19). The randomized controlled trials were identified through systematic searches of electronic databases through February 10, 2022. In total, 17 trials comprising 8,614 patients were included. Compared with exclusive standard care or placebo, IL-6 receptor antagonists with standard of care treatment were associated with a significantly reduced all-cause mortality at 28 days (pooled risk ratios [RR], 0.88; 95% confidence interval (CI), 0.82-0.95; 17 studies) and progression to invasive mechanical ventilation (RR, 0.79; 95% CI, 0.71-0.88; nine studies). Particularly, the subgroup of patients with moderate-to-severe COVID-19 showed a significant mortality benefit (RR, 0.89; 95% CI, 0.81-0.96; four studies) and a reduced risk for mechanical ventilation (RR, 0.80; 95% CI, 0.70-0.91; three studies) with tocilizumab treatment. The frequency of serious adverse events was lower in the tocilizumab treatment group than in the standard of care treatment group (RR, 0.83; 95% CI, 0.71-0.97; 11 studies), with no significant difference in the sarilumab treatment group (RR, 1.12; 95% CI, 0.89-1.40; four studies). Our meta-analysis demonstrated that tocilizumab treatment showed promising results in reducing 28-day mortality and progression to mechanical ventilation in patients with moderate-to-severe COVID-19, without the burden of serious adverse events.Trial registration: Clinical Trials Registry India identifier: CTRI/2020/05/025369.The proper registration is PROSPERO: registration number CRD42021294120.

Clinical update on COVID-19 for the emergency and critical care clinician: Medical management

INTRODUCTION

Coronavirus disease of 2019 (COVID-19) has resulted in millions of cases worldwide. As the pandemic has progressed, the understanding of this disease has evolved.

OBJECTIVE

This is the second part in a series on COVID-19 updates providing a focused overview of the medical management of COVID-19 for emergency and critical care clinicians.

DISCUSSION

COVID-19, caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), has resulted in significant morbidity and mortality worldwide. A variety of medical therapies have been introduced for use, including steroids, antivirals, interleukin-6 antagonists, monoclonal antibodies, and kinase inhibitors. These agents have each demonstrated utility in certain patient subsets. Prophylactic anticoagulation in admitted patients demonstrates improved outcomes. Further randomized data concerning aspirin in outpatients with COVID-19 are needed. Any beneficial impact of other therapies, such as colchicine, convalescent plasma, famotidine, ivermectin, and vitamins and minerals is not present in reliable medical literature. In addition, chloroquine and hydroxychloroquine are not recommended.

CONCLUSION

This review provides a focused update of the medical management of COVID-19 for emergency and critical care clinicians to help improve care for these patients.

The Association between TNF-α, IL-6, and Vitamin D Levels and COVID-19 Severity and Mortality: A Systematic Review and Meta-Analysis

BACKGROUND

An increasing number of scientific journals have proposed a connection between tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and the severity of COVID-19. Vitamin D has been discussed as a potential therapy for COVID-19 due to its immunomodulatory effects. This meta-analysis aims to determine the relationship, if any, between TNF-α, IL-6, vitamin D, and COVID-19 severity and mortality.

METHODS

The design of the study is a systematic review and meta-analysis. A literature search is performed using PubMed, Cochrane, ProQuest, and Google Scholar.

RESULTS

TNF-α insignificantly increases the risk of COVID-19 severity (adjusted odds ratio (aOR) = 1.0304; 95% CI 0.8178-1.2983; p = 0.80) but significantly increases the risk of COVID-19 mortality (crude hazard ratio (HR) = 1.0640; 95% CI 1.0259-1.1036; p = 0.0009). IL-6 significantly increases the risk of COVID-19 severity (aOR = 1.0284; 95% CI 1.0130-1.0441; p = 0.0003) and mortality (aOR = 1.0076; 95% CI 1.0004-1.0148; p = 0.04; adjusted hazard ratio (aHR) = 1.0036; 95% CI 1.0010-1.0061; p = 0.006). There is a statistically insignificant difference of the mean vitamin D levels between patients with severe COVID-19 and non-severe COVID-19 (mean difference (MD) = -5.0232; 95% CI 11.6832-1.6368; p = 0.14). A vitamin D deficiency insignificantly increases the risk of mortality of COVID-19 patients (aOR = 1.3827; 95% CI 0.7103-2.6916; p = 0.34).

CONCLUSION

IL-6 is an independent prognostic factor towards COVID-19 severity and mortality.