Therapeutic Role of Tocilizumab in SARS-CoV-2-Induced Cytokine Storm: Rationale and Current Evidence

Impact of FCGR2A rs1801274 and IL-6R rs2228145 polymorphisms on tocilizumab response in the Iranian population with severe COVID-19

BACKGROUND

Although several genetic biomarkers have been reported in the tocilizumab (TCZ) response in rheumatoid arthritis, no studies have addressed the pharmacogenomics effect of TCZ in COVID-19.

METHODS

In this prospective longitudinal study, 95 individuals with severe COVID-19 were selected between 2020-2022. The recovery process was measured at 24 h, 48 h, and 10 days before and after taking TCZ. All participants were genotyped using RFLP-PCR. Different genotypes of FCGR2A rs1801274 and IL-6R rs2228145 were compared in terms of the recovery process.

RESULTS

43.2% of patients were male and 56.8% were female with an average age of 58.20(± 16.214) years. The GA genotype for FCGR2A rs1801274 increased the risk of death (OR = 2.83, P = 0.038) and ventilation (OR = 2.71, P = 0.047) in TCZ-treated individuals. However, there was no risk of death and ventilation with IL-6R rs2228145 (P > 0.05). Additionally, docking analysis showed that not only IL6R but also FCGR2A can be a ligand for TCZ.

CONCLUSION

This study provides valuable insights into the impact of genetic variations on the response rate of TCZ in COVID-19 patients. The GA genotype for FCGR2A rs1801274 was associated with poor treatment outcomes.

Frontiers and hotspots evolution in cytokine storm: A bibliometric analysis from 2004 to 2022

Background

As a fatal disease, cytokine storm has garnered research attention in recent years. Nonetheless, as the body of related studies expands, a thorough and impartial evaluation of the current status of research on cytokine storms remains absent. Consequently, this study aimed to thoroughly explore the research landscape and evolution of cytokine storm utilizing bibliometric and knowledge graph approaches.

Methods

Research articles and reviews centered on cytokine storms were retrieved from the Web of Science Core Collection database. For bibliometric analysis, tools such as Excel 365, CiteSpace, VOSviewer, and the Bibliometrix R package were utilized.

Results

This bibliometric analysis encompassed 6647 articles published between 2004 and 2022. The quantity of pertinent articles and citation frequency exhibited a yearly upward trend, with a sharp increase starting in 2020. Network analysis of collaborations reveals that the United States holds a dominant position in this area, boasting the largest publication count and leading institutions. Frontiers in Immunology ranks as the leading journal for the largest publication count in this area. Stephan A. Grupp, a prominent researcher in this area, has authored the largest publication count and has the second-highest citation frequency. Research trends and keyword evaluations show that the connection between cytokine storm and COVID-19, as well as cytokine storm treatment, are hot topics in research. Furthermore, research on cytokine storm and COVID-19 sits at the forefront in this area.

Conclusion

This study employed bibliometric analysis to create a visual representation of cytokine storm research, revealing current trends and burgeoning topics in this area for the first time. It will provide valuable insights, helping scholars pinpoint critical research areas and potential collaborators.

Treatment of cytokine release syndrome-induced vascular endothelial injury using mesenchymal stem cells

Cytokine release syndrome (CRS) is an acute systemic inflammatory reaction in which hyperactivated immune cells suddenly release a large amount of cytokines, leading to exaggerated inflammatory responses, multiple organ dysfunction, and even death. Although palliative treatment strategies have significantly reduced the overall mortality, novel targeted treatment regimens with superior therapy efficacy are urgently needed. Vascular endothelial cells (ECs) are important target cells of systemic inflammation, and their destruction is considered to be the initiating event underlying many serious complications of CRS. Mesenchymal stem/stromal cells (MSCs) are multipotent cells with self-renewing differentiation capacity and immunomodulatory properties. MSC transplantation can effectively suppress the activation of immune cells, reduce the bulk release of cytokines, and repair damaged tissues and organs. Here, we review the molecular mechanisms underlying CRS-induced vascular endothelial injury and discuss potential treatments using MSCs. Preclinical studies demonstrate that MSC therapy can effectively repair endothelium damage and thus reduce the incidence and severity of ensuing CRS-induced complications. This review highlights the therapeutic role of MSCs in fighting against CRS-induced EC damage, and summarizes the possible therapeutic formulations of MSCs for improved efficacy in future clinical trials.

Establishment of sex-specific predictive models for critical illness in Chinese people with the Omicron variant

Introduction

The Omicron variant has rapidly spread throughout the world compared to the Delta variant and poses a great threat to global healthcare systems due to its immune evasion and rapid spread. Sex has been identified as a factor significantly associated with COVID-19 mortality, but it remains unclear which clinical indicators could be identified as risk factors in each sex group and which sex-specific risk factors might shape the worse clinical outcome, especially for Omicrons. This study aimed to confirm the relationship between sex and the progression of the Omicron variant and to explore its sex-biased risk factors.

Methods

We conducted a retrospective study including 1,132 hospitalized patients with the COVID-19 Omicron variant from 5 December 2022 to 25 January 2023 at Shanghai General Hospital, and the medical history data and clinical index data of the inpatients for possible sex differences were compared and analyzed. Then, a sex-specific Lasso regression was performed to select the variables significantly associated with critical illness, including intensive care unit admission, invasive mechanical ventilation, or death. A logistic regression was used to construct a sex-specific predictive model distinctively for the critical illness outcome using selected covariates.

Results

Among the collected 115 clinical indicators, up to 72 showed significant sex differences, including the difference in merit and the proportion of people with abnormalities. More importantly, males had greater critical illness (28.4% vs. 19.9%) and a significantly higher intensive care unit occupancy (20.96% vs. 14.49%) and mortality (13.2% vs. 4.9%), and males over 80 showed worse outcomes than females. Predictive models (AUC: 0.861 for males and 0.898 for females) showed 12 risk factors for males and 10 for females. Through a comprehensive sex-stratified analysis of a large cohort of hospitalized Omicron-infected patients, we identified the specific risk factors for critical illness by developing prediction models.

Discussion

Sex disparities and the identified risk factors should be considered, especially in the personalized prevention and treatment of the COVID-19 Omicron variant.

The value of age IgG and IL6 in estimating time of viral clearance in asymptomatic or mild patients with COVID-19

Background

The aim of this study was to investigate the relationship between Age, immunoglobin G (IgG), immunoglobin M (IgM), procalcitonin (PCT), and interleukin-6 (IL6), and the time to clear viral nucleic acids in asymptomatic and mild coronavirus disease 2019 (COVID-19) patients, as well as evaluated the predictive value of these biochemical indicators.

Methods

We performed a retrospective analysis on 1,570 individuals who were admitted to Tianjin First Central Hospital and diagnosed with asymptomatic or mild cases. Laboratory data were collected, including age, gender, levels of IgG, IgM, PCT and IL6, as well as results of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) nucleic acid test. These data were statistically analyzed using SPSS software, version 24.0.

Results

The results indicated that among mild patients, Age, IgG, and the time to clear viral nucleic acids were higher than asymptomatic patients (p < 0.05). And the time to clear viral nucleic acids was significantly correlated with Age, IgG, IgM, PCT, and IL6 (p < 0.05), IgG (r = -0.445, p < 0.001) showed moderate correlations. Using logistic regression analysis, we identified older age, high IL6 levels, and low IgG levels were risk factors for nucleic acid clearance exceeding 14 days (p < 0.05). When combining these three indicators to predict the probability of nucleic acid clearance exceeding 14 days in the 1,570 patients, the AUROC was found to be 0.727.

Conclusion

Age, IgG, and IL6 could potentially serve as useful predictors for nucleic acid clearance exceeding 14 days in asymptomatic and mild COVID-19 patients.

Genetic Predisposition to SARS-CoV-2 Infection: Cytokine Polymorphism and Disease Transmission within Households

We addressed the question of the influence of the molecular polymorphism of cytokines from different T helper subsets on the susceptibility to SARS-CoV-2 infection. From a cohort of 527 samples (collected from 26 May 2020 to 31 March 2022), we focused on individuals living in the same household (n = 58) with the SARS-CoV-2-infected person. We divided them into households with all individuals SARS-CoV-2 PCR positive (n = 29, households, 61 individuals), households with mixed PCR pattern (n = 24, 62) and negative households (n = 5, 15), respectively. TGF-β1 and IL-6 were the only cytokines tested with a significant difference between the cohorts. We observed a shift toward Th2 and the regulatory Th17 and Treg subset regulation for households with all members infected compared to those without infection. These data indicate that the genetically determined balance between the cytokines acting on different T helper cell subsets may play a pivotal role in transmission of and susceptibility to SARS-CoV-2 infection. Contacts infected by their index persons were more likely to highly express TGF-β1, indicating a reduced inflammatory response. Those not infected after contact had a polymorphism leading to a higher IL-6 expression. IL-6 acts in innate immunity, allergy and on the T helper cell differentiation, explaining the reduced susceptibility to SARS-CoV-2.

Molecular Determinants, Clinical Manifestations and Effects of Immunization on Cardiovascular Health During COVID-19 Pandemic Era - A Review

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has enveloped the world into an unprecedented pandemic since 2019. Significant damage to multiple organs, such as the lungs and heart, has been extensively reported. Cardiovascular injury by ACE2 downregulation, hypoxia-induced myocardial injury, and systemic inflammatory responses complicate the disease. This virus causes multisystem inflammatory syndrome in children with similar symptoms to adult SARS-CoV-2-induced myocarditis. While several treatment strategies and immunization programs have been implemented to control the menace of this disease, the risk of long-term cardiovascular damage associated with the disease has not been adequately assessed. In this review, we surveyed and summarized all the available information on the effects of COVID-19 on cardiovascular health as well as comorbidities. We also examined several case reports on post-immunization cardiovascular complications.

Effect of plant produced Anti-hIL-6 receptor antibody blockade on pSTAT3 expression in human peripheral blood mononuclear cells

As a response to invasion by pathogens, the secretion of interleukin 6 (IL-6) which is a cytokine, activates IL-6/JAKs/STAT3 intracellular signaling via., phosphorylation. Over expression of pSTAT3 induces IL-6 positive feedback loop causing cytokine release syndrome or cytokine storm. Plants have gained momentum as an alternative expression system. Hence, this study aims to produce mAb targeting human IL-6 receptor (hIL-6R) in Nicotiana benthamiana for down regulating its cellular signaling thus, decreasing the expression of pSTAT3. The variable regions of heavy and light chains of anti-hIL-6R mAb were constructed in pBYK2e geminiviral plant expression vector and transiently co-expressed in N. benthamiana. The results demonstrate the proper protein assembly of anti-hIL-6R mAb with highest expression level of 2.24 mg/g FW at 5 dpi, with a yield of 21.4 µg/g FW after purification. The purity and N-glycosylation of plant produced antibody was analyzed, including its specificity to human IL-6 receptor by ELISA. Additionally, we investigated the effect to pSTAT3 expression in human PBMC's by flow cytometry wherein, the results confirmed lower expression of pSTAT3 with increasing concentrations of plant produced anti-hIL-6R mAb. Although, further in vivo studies are key to unveil the absolute functionality of anti-hIL-6R, we hereby show the potential of the plant platform and its suitability for the production of this therapeutic antibody.

Anti-inflammatory effects of medications used for viral infection-induced respiratory diseases

Respiratory viruses like rhinovirus, influenza virus, respiratory syncytial virus, and coronavirus cause several respiratory diseases, such as bronchitis, pneumonia, pulmonary fibrosis, and coronavirus disease 2019, and exacerbate bronchial asthma, chronic obstructive pulmonary disease, bronchiectasis, and diffuse panbronchiolitis. The production of inflammatory mediators and mucin and the accumulation of inflammatory cells have been reported in patients with viral infection-induced respiratory diseases. Interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, granulocyte-macrophage colony-stimulating factor, and regulated on activation normal T-cell expressed and secreted are produced in the cells, including human airway and alveolar epithelial cells, partly through the activation of toll-like receptors, nuclear factor kappa B and p44/42 mitogen-activated protein kinase. These mediators are associated with the development of viral infection-induced respiratory diseases through the induction of inflammation and injury in the airway and lung, airway remodeling and hyperresponsiveness, and mucus secretion. Medications used to treat respiratory diseases, including corticosteroids, long-acting β2-agonists, long-acting muscarinic antagonists, mucolytic agents, antiviral drugs for severe acute respiratory syndrome coronavirus 2 and influenza virus, macrolides, and Kampo medicines, reduce the production of viral infection-induced mediators, including cytokines and mucin, as determined in clinical, in vivo, or in vitro studies. These results suggest that the anti-inflammatory effects of these medications on viral infection-induced respiratory diseases may be associated with clinical benefits, such as improvements in symptoms, quality of life, and mortality rate, and can prevent hospitalization and the exacerbation of chronic obstructive pulmonary disease, bronchial asthma, bronchiectasis, and diffuse panbronchiolitis.

Age-related Differences in Immune Reactions to SARS-CoV-2 Spike and Nucleocapsid Antigens

BACKGROUND/AIM

The manifestation and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections show a clear correlation to the age of a patient. The younger a person, the less likely the infection results in significant illness. To explore the immunological characteristics behind this phenomenon, we studied the course of SARS-CoV-2 infections in 11 households, including 8 children and 6 infants/neonates of women who got infected with SARS-CoV-2 during pregnancy.

MATERIALS AND METHODS

We investigated the immune responses of peripheral blood mononuclear cells (PBMCs), umbilical cord blood mononuclear cells (UCBCs), and T cells against spike and nucleocapsid antigens of SARS-COV-2 by flow cytometry and cytokine secretion assays.

RESULTS

Upon peptide stimulation, UCBC from neonates showed a strongly reduced IFN-γ production, as well as lower levels of IL-5, IL-13, and TNF-α alongside with decreased frequencies of surface CD137/PD-1 co-expressing CD4⁺ and CD+8 T cells compared with adult PBMCs. The PBMC response of older children instead was characterized by elevated frequencies of IFN-γ+ CD4⁺ T cells, but significantly lower levels of multiple cytokines (IL-5, IL-6, IL-9, IL-10, IL-17A, and TNF-α) and a marked shift of the CD4⁺/CD8⁺ T-cell ratio towards CD8⁺ T cells in comparison to adults.

CONCLUSION

The increased severity of SARS-CoV-2 infections in adults could result from the strong cytokine production and lower potential to immunomodulate the excessive inflammation, while the limited IFN-γ production of responding T cells in infants/neonates and the additional higher frequencies of CD8⁺ T cells in older children may provide advantages during the course of a SARS-CoV-2 infection.

Efficacy and marginal cost of treatment with tocilizumab in COVID-19 patients

OBJECTIVE

To describe the marginal cost and survival of patients treated with tocilizumab in a university hospital under real-life conditions and to evaluate factors that could influence costs and health outcomes will be evaluated.

METHODS

Observational, single-center, retrospective study of a cohort of adult patients infected with SARS-CoV-2 treated with tocilizumab. The one-year restricted mean survival time was analyzed in life-years gained (LYG). The influence of sex, age and severity on patient survival was evaluated. The marginal cost/LYG and marginal cost/survivor ratios were calculated.

RESULTS

508 patients (66 ± 13 years; 32% women) were included. Seventeen percent were admitted to the ICU. Overall survival was 77%. Age older than 71.5 years (HR = 1.08; 95% CI 1.07-1.10; p < 0.001) and ICU admission at initiation of treatment (HR = 2.01; 95% CI 1.30-3.09; p = 0.002) were identified as risk factors. The total budgetary impact of tocilizumab in the period analyzed was 206,466 euros. The patients with the highest cost per unit of health outcome were those admitted to the ICU and those over 71.5 years, with a marginal cost/LYG of € 966 and a marginal cost/survivor of € 1,136.

CONCLUSION

The efficiency of treatment with tocilizumab is associated with the age and severity of the patients. The figures are lower in all subgroups than the thresholds usually used in cost-effectiveness evaluations. The results of the present study suggest that early first dose of tocilizumab is an efficient strategy.

[Translated article] Efficacy and marginal cost of treatment with tocilizumab in COVID-19 patients

OBJECTIVE

To describe the marginal cost and survival of patients treated with tocilizumab in a university hospital under real-life conditions and to evaluate factors that could influence costs and health outcomes will be evaluated.

METHODS

Observational, single-center, retrospective study of a cohort of adult patients infected with SARS-COV2 treated with tocilizumab. The 1 year restricted mean survival time was analyzed in life-years gained (LYG). The influence of sex, age and severity on patient survival was evaluated. The marginal cost/LYG and marginal cost/survivor ratios were calculated.

RESULTS

508 patients (66 ± 13 years; 32% women) were included. Seventeen percent were admitted to the ICU. Overall survival was 77%. Age older than 71.5 years (HR = 1.08; 95% CI 1.07-1.10; p < 0.001) and ICU admission at initiation of treatment (HR = 2.01; 95% CI 1.30-3.09; p = 0.002) were identified as risk factors. The total budgetary impact of tocilizumab in the period analyzed was 206,466 euros. The patients with the highest cost per unit of health outcome were those admitted to the ICU and those over 71.5 years, with a marginal cost/LYG of €966 and a marginal cost/survivor of €1136.

CONCLUSION

The efficiency of treatment with tocilizumab is associated with the age and severity of the patients. The figures are lower in all subgroups than the thresholds usually used in cost-effectiveness evaluations. The results of the present study suggest that early first dose of tocilizumab is an efficient strategy.

Drugs for COVID-19: An Update

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was the seventh known human coronavirus, and it was identified in Wuhan, Hubei province, China, in 2020. It caused the highly contagious disease called coronavirus disease 2019 (COVID-19), declared a global pandemic by the World Health Organization (WHO) on 11 March 2020. A great number of studies in the search of new therapies and vaccines have been carried out in these three long years, producing a series of successes; however, the need for more effective vaccines, therapies and other solutions is still being pursued. This review represents a tracking shot of the current pharmacological therapies used for the treatment of COVID-19.

Utilizing clinical pharmacology in the drug repurposing arena: a look into COVID-19

INTRODUCTION

Drug repurposing represented an important contribution in the management of COVID-19, becoming the first line of defense to mitigate the effects of the new coronavirus. In a brief time, drug repurposing (DR) provided potentially effective and already available drugs for COVID-19, while specific therapies against SARS-CoV-2 and/or vaccines were developing. Identifying repurposed drugs requires a multidisciplinary approach, where clinical pharmacology represents the missing piece of the puzzle.

AREAS COVERED

Nowadays, clinical pharmacology is recognized as a discipline at the core of translational science, whose activities lead to the identification of the right drug for the right patient. In the context of the COVID-19 pandemic, its role in drug development and therapy choice has been decisive and itself repositioned. In this review, we tried to highlight the important role of clinical pharmacology in the identification and evaluation of possible repurposed drugs for COVID-19.

EXPERT OPINION

We believe that clinical pharmacology had an important role in identifying patient-oriented therapy during the COVID-19 pandemic. In this context, DR was just one of the challenges for clinical pharmacology, which proved that this discipline is ready to respond to future threats.

Nanoscale Technologies in the Fight against COVID-19: From Innovative Nanomaterials to Computer-Aided Discovery of Potential Antiviral Plant-Derived Drugs

The last few years have increasingly emphasized the need to develop new active antiviral products obtained from artificial synthesis processes using nanomaterials, but also derived from natural matrices. At the same time, advanced computational approaches have found themselves fundamental in the repurposing of active therapeutics or for reducing the very long developing phases of new drugs discovery, which represents a real limitation, especially in the case of pandemics. The first part of the review is focused on the most innovative nanomaterials promising both in the field of therapeutic agents, as well as measures to control virus spread (i.e., innovative antiviral textiles). The second part of the review aims to show how computer-aided technologies can allow us to identify, in a rapid and therefore constantly updated way, plant-derived molecules (i.e., those included in terpenoids) potentially able to efficiently interact with SARS-CoV-2 cell penetration pathways.

Deferiprone: A Forty-Year-Old Multi-Targeting Drug with Possible Activity against COVID-19 and Diseases of Similar Symptomatology

The need for preparing new strategies for the design of emergency drug therapies against COVID-19 and similar diseases in the future is rather urgent, considering the high rate of morbidity and especially mortality associated with COVID-19, which so far has exceeded 18 million lives. Such strategies could be conceived by targeting the causes and also the serious toxic side effects of the diseases, as well as associated biochemical and physiological pathways. Deferiprone (L1) is an EMA- and FDA-approved drug used worldwide for the treatment of iron overload and also other conditions where there are no effective treatments. The multi-potent effects and high safety record of L1 in iron loaded and non-iron loaded categories of patients suggests that L1 could be developed as a “magic bullet” drug against COVID-19 and diseases of similar symptomatology. The mode of action of L1 includes antiviral, antimicrobial, antioxidant, anti-hypoxic and anti-ferroptotic effects, iron buffering interactions with transferrin, iron mobilizing effects from ferritin, macrophages and other cells involved in the immune response and hyperinflammation, as well as many other therapeutic interventions. Similarly, several pharmacological and other characteristics of L1, including extensive tissue distribution and low cost of production, increase the prospect of worldwide availability, as well as many other therapeutic approach strategies involving drug combinations, adjuvant therapies and disease prevention.

COVID-19 and the role of cytokines in this disease

Studies have shown that SARS-CoV-2 has the ability to activate and mature proinflammatory cytokines in the body. Cytokine markers are a group of polypeptide signalling molecules that can induce and regulate many cellular biological processes by stimulating cell receptors at the surface. SARS-CoV-2 has been shown to be associated with activation of innate immunity, and an increase in neutrophils, mononuclear phagocytes, and natural killer cells has been observed, as well as a decrease in T cells including CD4+ and CD8. It is noteworthy that during the SARS-CoV-2 infection, an increase in the secretion or production of IL-6 and IL-8 is seen in COVID-19 patients along with a decrease in CD4+ and CD8+ and T cells in general. SARS-CoV-2 has been shown to significantly increase Th2, Th1/Th17 cells and antibody production in the body of patients with COVID-19. Specific immune profiles of SARS-CoV-2 infection can lead to secondary infections and dysfunction of various organs in the body. It has been shown that Interleukins (such as IL-1, IL-4, IL-6, IL-7, IL-10, IL-12, IL-17, and IL-18), IFN-γ, TNF-α,TGF-β and NF-κB play major roles in the body's inflammatory response to SARS-CoV-2 infection. The most important goal of this review is to study the role of inflammatory cytokines in COVID-19.

Newly Emerged Antiviral Strategies for SARS-CoV-2: From Deciphering Viral Protein Structural Function to the Development of Vaccines, Antibodies, and Small Molecules

Coronavirus disease 2019 (COVID-19) caused by the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become the most severe health crisis, causing extraordinary economic disruption worldwide. SARS-CoV-2 is a single-stranded RNA-enveloped virus. The process of viral replication and particle packaging is finished in host cells. Viral proteins, including both structural and nonstructural proteins, play important roles in the viral life cycle, which also provides the targets of treatment. Therefore, a better understanding of the structural function of virus proteins is crucial to speed up the development of vaccines and therapeutic strategies. Currently, the structure and function of proteins encoded by the SARS-CoV-2 genome are reviewed by several studies. However, most of them are based on the analysis of SARS-CoV-1 particles, lacking a systematic review update for SARS-CoV-2. Here, we specifically focus on the structure and function of proteins encoded by SARS-CoV-2. Viral proteins that contribute to COVID-19 infection and disease pathogenesis are reviewed according to the most recent research findings. The structure-function correlation of viral proteins provides a fundamental rationale for vaccine development and targeted therapy. Then, current antiviral vaccines are updated, such as inactive viral vaccines and protein-based vaccines and DNA, mRNA, and circular RNA vaccines. A summary of other therapeutic options is also reviewed, including monoclonal antibodies such as a cross-neutralizer antibody, a constructed cobinding antibody, a dual functional monoclonal antibody, an antibody cocktail, and an engineered bispecific antibody, as well as peptide-based inhibitors, chemical compounds, and clustered regularly interspaced short palindromic repeats (CRISPR) exploration. Overall, viral proteins and their functions provide the basis for targeted therapy and vaccine development.

Multisystem Inflammatory Syndrome and Autoimmune Diseases Following COVID-19: Molecular Mechanisms and Therapeutic Opportunities

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), has led to huge concern worldwide. Some SARS-CoV-2 infected patients may experience post–COVID-19 complications such as multisystem inflammatory syndrome, defined by symptoms including fever and elevated inflammatory markers (such as elevation of C reactive protein (CRP), erythrocyte sedimentation rate, fibrinogen, procalcitonin test, D-dimer, ferritin, lactate dehydrogenase or IL-6, presence of neutrophilia, lymphopenia, decreased albumin, and multiple organ dysfunction). Post–COVID-19 complications may also manifest as autoimmune diseases such as Guillain-Barré syndrome and systemic lupus erythematosus. Signaling disorders, increased inflammatory cytokines secretion, corticosteroid use to treat COVID-19 patients, or impaired immune responses are suggested causes of autoimmune diseases in these patients. In this review, we discuss the molecular and pathophysiological mechanisms and therapeutic opportunities for multisystem inflammatory syndrome and autoimmune diseases following SARS-CoV-2 infection with the aim to provide a clear view for health care providers and researchers.

Targeting Specific Checkpoints in the Management of SARS-CoV-2 Induced Cytokine Storm

COVID-19-infected patients require an intact immune system to suppress viral replication and prevent complications. However, the complications of SARS-CoV-2 infection that led to death were linked to the overproduction of proinflammatory cytokines known as cytokine storm syndrome. This article reported the various checkpoints targeted to manage the SARS-CoV-2-induced cytokine storm. The literature search was carried out using PubMed, Embase, MEDLINE, and China National Knowledge Infrastructure (CNKI) databases. Journal articles that discussed SARS-CoV-2 infection and cytokine storm were retrieved and appraised. Specific checkpoints identified in managing SARS-CoV-2 induced cytokine storm include a decrease in the level of Nod-Like Receptor 3 (NLRP3) inflammasome where drugs such as quercetin and anakinra were effective. Janus kinase-2 and signal transducer and activator of transcription-1 (JAK2/STAT1) signaling pathways were blocked by medicines such as tocilizumab, baricitinib, and quercetin. In addition, inhibition of interleukin (IL)-6 with dexamethasone, tocilizumab, and sarilumab effectively treats cytokine storm and significantly reduces mortality caused by COVID-19. Blockade of IL-1 with drugs such as canakinumab and anakinra, and inhibition of Bruton tyrosine kinase (BTK) with zanubrutinib and ibrutinib was also beneficial. These agents' overall mechanisms of action involve a decrease in circulating proinflammatory chemokines and cytokines and or blockade of their receptors. Consequently, the actions of these drugs significantly improve respiration and raise lymphocyte count and PaO₂/FiO₂ ratio. Targeting cytokine storms' pathogenesis genetic and molecular apparatus will substantially enhance lung function and reduce mortality due to the COVID-19 pandemic.

Cellular metabolic basis of altered immunity in the lungs of patients with COVID-19

Metabolic pathways drive cellular behavior. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes lung tissue damage directly by targeting cells or indirectly by producing inflammatory cytokines. However, whether functional alterations are related to metabolic changes in lung cells after SARS-CoV-2 infection remains unknown. Here, we analyzed the lung single-nucleus RNA-sequencing (snRNA-seq) data of several deceased COVID-19 patients and focused on changes in transcripts associated with cellular metabolism. We observed upregulated glycolysis and oxidative phosphorylation in alveolar type 2 progenitor cells, which may block alveolar epithelial differentiation and surfactant secretion. Elevated inositol phosphate metabolism in airway progenitor cells may promote neutrophil infiltration and damage the lung barrier. Further, multiple metabolic alterations in the airway goblet cells are associated with impaired muco-ciliary clearance. Increased glycolysis, oxidative phosphorylation, and inositol phosphate metabolism not only enhance macrophage activation but also contribute to SARS-CoV-2 induced lung injury. The cytotoxicity of natural killer cells and CD8⁺ T cells may be enhanced by glycerolipid and inositol phosphate metabolism. Glycolytic activation in fibroblasts is related to myofibroblast differentiation and fibrogenesis. Glycolysis, oxidative phosphorylation, and glutathione metabolism may also boost the aging, apoptosis and proliferation of vascular smooth muscle cells, resulting in pulmonary arterial hypertension. In conclusion, this preliminary study revealed a possible cellular metabolic basis for the altered innate immunity, adaptive immunity, and niche cell function in the lung after SARS-CoV-2 infection. Therefore, patients with COVID-19 may benefit from therapeutic strategies targeting cellular metabolism in future.

Structural biology of SARS-CoV-2: open the door for novel therapies

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is the causative agent of the pandemic disease COVID-19, which is so far without efficacious treatment. The discovery of therapy reagents for treating COVID-19 are urgently needed, and the structures of the potential drug-target proteins in the viral life cycle are particularly important. SARS-CoV-2, a member of the Orthocoronavirinae subfamily containing the largest RNA genome, encodes 29 proteins including nonstructural, structural and accessory proteins which are involved in viral adsorption, entry and uncoating, nucleic acid replication and transcription, assembly and release, etc. These proteins individually act as a partner of the replication machinery or involved in forming the complexes with host cellular factors to participate in the essential physiological activities. This review summarizes the representative structures and typically potential therapy agents that target SARS-CoV-2 or some critical proteins for viral pathogenesis, providing insights into the mechanisms underlying viral infection, prevention of infection, and treatment. Indeed, these studies open the door for COVID therapies, leading to ways to prevent and treat COVID-19, especially, treatment of the disease caused by the viral variants are imperative.

Tocilizumab-Induced Unexpected Increase of Several Inflammatory Cytokines in Critically Ill COVID-19 Patients: The Anti-Inflammatory Side of IL-6

Early evidence during the coronavirus disease 2019 (COVID-19) pandemic indicated high levels of interleukin (IL)-6 in patients with severe COVID-19. This led to the off-label use of tocilizumab (TCZ) during the first wave of the pandemic. While the monoclonal antibody blocks IL-6 pathway, its effect on other inflammatory cytokines remains poorly described. To better understand the effect of TCZ on the biological inflammatory profile, we monitored a large panel of inflammatory cytokines in critically ill COVID-19 patients receiving off-label TCZ. Twenty-three patients with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were included in the study, among which 15 patients received TCZ and 8 patients did not. Serum samples were collected for 8 days, before and following TCZ administration or hospital admission for the control group. Serum profile of 12 cytokines (IL-1β, -2, -4, -6, -8, -10, -12, -13, -17, -18, tumor necrosis factor α (TNF-α), interferon-gamma (IFN-γ), and sIL-6R were assessed in these two groups. Although the increased IL-6 concentrations after TCZ infusion were expected, we observed an unexpected increase in IL-1β, -2, -4, -10, -12p70, -18, and sIL-6R levels in the treated patients with maximal values reaching 2 to 4 days after TCZ. In contrast, no change in cytokine levels was observed in the control group. Our results suggested that some inflammatory pathways escape IL-6R blockade and even appeared amplified. This finding highlights an old observation of the anti-inflammatory effects of IL-6 as already suggested over 20 years ago. Clinical Trial Registration number: NCT04346017.

Specific cytokines of interleukin-6 family interact with S100 proteins

Cytokines of interleukin-6 (IL-6) family are important signaling proteins involved in various physiological and pathological processes. Earlier, we described interactions between IL-11 and S100P/B proteins from the family of S100 proteins engaged in the pathogenesis of numerous diseases. We probed here interactions between seven IL-6 family cytokines (IL-6, IL-11, OSM, LIF, CNTF, CT-1, and CLCF1) and fourteen S100 proteins (S100A1/A4/A6/A7/A8/A9/A10/A11/A12/A13/A14/A15/B/P). Surface plasmon resonance spectroscopy revealed formation of calcium-dependent complexes between IL-11, OSM, CNTF, CT-1, and CLCF1 and distinct subsets of S100A1/A6/B/P proteins with equilibrium dissociation constants of 19 nM - 12 µM. The existence of a network of interactions between Ca²⁺-loaded S100 proteins and IL-6 family cytokines suggest regulation of these cytokines by the extracellular forms of S100 proteins.

Targeting the PI3K/Akt/mTOR pathway: A therapeutic strategy in COVID-19 patients

Some COVID-19 patients suffer complications from anti-viral immune responses which can lead to both a dangerous cytokine storm and development of blood-borne factors that render severe thrombotic events more likely. The precise immune response profile is likely, therefore, to determine and predict patient outcomes and also represents a target for intervention. Anti-viral T cell exhaustion in the early stages is associated with disease progression. Dysregulation of T cell functions, which precedes cytokine storm development and neutrophil expansion in alveolar tissues heralds damaging pathology.T cell function, cytokine production and factors that attract neutrophils to the lung can be modified through targeting molecules that can modulate T cell responses. Manipulating T cell responses by targeting the PI3K/Akt/mTOR pathway could provide the means to control the immune response in COVID-19 patients. During the initial anti-viral response, T cell effector function can be enhanced by delaying anti-viral exhaustion through inhibiting PI3K and Akt. Additionally, immune dysregulation can be addressed by enhancing immune suppressor functions by targeting downstream mTOR, an important intracellular modulator of cellular metabolism. Targeting this signalling pathway also has potential to prevent formation of thrombi due to its role in platelet activation. Furthermore, this signalling pathway is essential for SARS-cov-2 virus replication in host cells and its inhibition could, therefore, reduce viral load. The ultimate goal is to identify targets that can quickly control the immune response in COVID-19 patients to improve patient outcome. Targeting different levels of the PI3K/Akt/mTOR signalling pathway could potentially achieve this during each stage of the disease.

COVID-19 and Rheumatoid Arthritis Crosstalk: Emerging Association, Therapeutic Options and Challenges

Hyperactivation of immune responses resulting in excessive release of pro-inflammatory mediators in alveoli/lung structures is the principal pathological feature of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The cytokine hyperactivation in COVID-19 appears to be similar to those seen in rheumatoid arthritis (RA), an autoimmune disease. Emerging evidence conferred the severity and risk of COVID-19 to RA patients. Amid the evidence of musculoskeletal manifestations involving immune-inflammation-dependent mechanisms and cases of arthralgia and/or myalgia in COVID-19, crosstalk between COVID-19 and RA is often debated. The present article sheds light on the pathological crosstalk between COVID-19 and RA, the risk of RA patients in acquiring SARS-CoV-2 infection, and the aspects of SARS-CoV-2 infection in RA development. We also conferred whether RA can exacerbate COVID-19 outcomes based on available clinical readouts. The mechanistic overlapping in immune-inflammatory features in both COVID-19 and RA was discussed. We showed the emerging links of angiotensin-converting enzyme (ACE)-dependent and macrophage-mediated pathways in both diseases. Moreover, a detailed review of immediate challenges and key recommendations for anti-rheumatic drugs in the COVID-19 setting was presented for better clinical monitoring and management of RA patients. Taken together, the present article summarizes available knowledge on the emerging COVID-19 and RA crosstalk and their mechanistic overlaps, challenges, and therapeutic options.

Cefiderocol treatment for carbapenem-resistant Acinetobacter baumannii infection in the ICU during the COVID-19 pandemic: a multicentre cohort study

Objectives

To analyse the impact of cefiderocol use on outcome in patients admitted to the ICU for severe COVID-19 and further diagnosed with carbapenem-resistant Acinetobacter baumannii (CR-Ab) infection.

Methods

Retrospective multicentre observational study was performed at four Italian hospitals, from January 2020 to April 2021. Adult patients admitted to ICU for severe COVID-19 and further diagnosed with CR-Ab infections were enrolled. Patients treated with cefiderocol, as compassionate use, for at least 72 h were compared with those receiving alternative regimens. Primary endpoint was all-cause 28 day mortality. The impact of cefiderocol on mortality was evaluated by multivariable Cox regression model.

Results

In total, 107 patients were enrolled (76% male, median age 65 years). The median time from ICU admission to CR-Ab infection diagnosis was 14 (IQR 8–20) days, and the main types of CR-Ab infections were bloodstream infection (58%) and lower respiratory tract infection (41%). Cefiderocol was administered to 42 patients within a median of 2 (IQR 1–4) days after CR-Ab infection diagnosis and as monotherapy in all cases. The remaining patients received colistin, mostly (82%) administered as combination therapy. All-cause 28 day mortality rate was 57%, without differences between groups (cefiderocol 55% versus colistin 58% P = 0.70). In multivariable analysis, the independent risk factor for mortality was SOFA score (HR 1.24, 95% CI 1.15–1.38, P < 0.001). Cefiderocol was associated with a non-significant lower mortality risk (HR 0.64, 95% CI 0.38–1.08, P = 0.10).

Conclusions

Our study confirms the potential role of cefiderocol in the treatment of CR-Ab infection, but larger clinical studies are needed.

Emerging nanomaterials applied for tackling the COVID-19 cytokine storm

During the global outbreak of coronavirus disease 2019 (COVID-19), a hyperinflammatory state called the cytokine storm was recognized as a major contributor to multiple organ failure and mortality. However, to date, the diagnosis and treatment of the cytokine storm remain major challenges for the clinical prognosis of COVID-19. In this review, we outline various nanomaterial-based strategies for preventing the COVID-19 cytokine storm. We highlight the contribution of nanomaterials to directly inhibit cytokine release. We then discuss how nanomaterials can be used to deliver anti-inflammatory drugs to calm the cytokine storm. Nanomaterials also play crucial roles in diagnostics. Nanomaterial-based biosensors with improved sensitivity and specificity can be used to detect cytokines. In summary, emerging nanomaterials offer platforms and tools for the detection and treatment of the COVID-19 cytokine storm and future pandemic.

From Infection to Immunity: Understanding the Response to SARS-CoV2 Through In-Silico Modeling

Background

Immune system conditions of the patient is a key factor in COVID-19 infection survival. A growing number of studies have focused on immunological determinants to develop better biomarkers for therapies.

Aim

Studies of the insurgence of immunity is at the core of both SARS-CoV-2 vaccine development and therapies. This paper attempts to describe the insurgence (and the span) of immunity in COVID-19 at the population level by developing an in-silico model. We simulate the immune response to SARS-CoV-2 and analyze the impact of infecting viral load, affinity to the ACE2 receptor, and age in an artificially infected population on the course of the disease.

Methods

We use a stochastic agent-based immune simulation platform to construct a virtual cohort of infected individuals with age-dependent varying degrees of immune competence. We use a parameter set to reproduce known inter-patient variability and general epidemiological statistics.

Results

By assuming the viremia at day 30 of the infection to be the proxy for lethality, we reproduce in-silico several clinical observations and identify critical factors in the statistical evolution of the infection. In particular, we evidence the importance of the humoral response over the cytotoxic response and find that the antibody titers measured after day 25 from the infection are a prognostic factor for determining the clinical outcome of the infection. Our modeling framework uses COVID-19 infection to demonstrate the actionable effectiveness of modeling the immune response at individual and population levels. The model developed can explain and interpret observed patterns of infection and makes verifiable temporal predictions. Within the limitations imposed by the simulated environment, this work proposes quantitatively that the great variability observed in the patient outcomes in real life can be the mere result of subtle variability in the infecting viral load and immune competence in the population. In this work, we exemplify how computational modeling of immune response provides an important view to discuss hypothesis and design new experiments, in particular paving the way to further investigations about the duration of vaccine-elicited immunity especially in the view of the blundering effect of immunosenescence.

Efficacy of Tocilizumab Therapy in Different Subtypes of COVID-19 Cytokine Storm Syndrome

Background: Cytokine storm in COVID-19 is heterogenous. There are at least three subtypes: cytokine release syndrome (CRS), macrophage activation syndrome (MAS), and sepsis. Methods: A retrospective study comprising 276 patients with SARS-CoV-2 pneumonia. All patients were tested for ferritin, interleukin-6, D-Dimer, fibrinogen, calcitonin, and C-reactive protein. According to the diagnostic criteria, three groups of patients with different subtypes of cytokine storm syndrome were identified: MAS, CRS or sepsis. In the MAS and CRS groups, treatment results were assessed depending on whether or not tocilizumab was used. Results: MAS was diagnosed in 9.1% of the patients examined, CRS in 81.8%, and sepsis in 9.1%. Median serum ferritin in patients with MAS was significantly higher (5894 vs. 984 vs. 957 ng/mL, p < 0.001) than in those with CRS or sepsis. Hypofibrinogenemia and pancytopenia were also observed in MAS patients. In CRS patients, a higher mortality rate was observed among those who received tocilizumab, 21 vs. 10 patients (p = 0.043), RR = 2.1 (95% CI 1.0–4.3). In MAS patients, tocilizumab decreased the mortality, 13 vs. 6 patients (p = 0.013), RR = 0.50 (95% CI 0.25–0.99). Conclusions: Tocilizumab therapy in patients with COVID-19 and CRS was associated with increased mortality, while in MAS patients, it contributed to reduced mortality.