The role of IL-6 and IL-6 blockade in COVID-19

The antidepressant effect of whole-body hyperthermia is associated with the classical interleukin-6 signaling pathway

There is urgent need for novel antidepressant treatments that confer therapeutic benefits via engagement with identified mechanistic targets. The objective of the study was to determine whether activation of the classical anti-inflammatory interleukin-6 signaling pathways is associated with the antidepressant effects of whole-body hyperthermia. A 6-week, randomized, double-blind study compared whole-body hyperthermia with a sham condition in a university-based medical center. Medically healthy participants aged 18-65 years who met criteria for major depressive disorder, were free of psychotropic medication use, and had a baseline 17-item Hamilton Depression Rating Scale score ≥ 16 were randomized with 1-to-1 allocation in blocks of 6 to receive whole-body hyperthermia or sham. Of 338 individuals screened, 34 were randomized, 30 received interventions and 26 had ≥ 2 blood draws and depressive symptom assessments. Secondary data analysis examined change in the ratio of IL-6:soluble IL-6 receptor pre-intervention, post-intervention, and at weeks 1 and 4. Hierarchical linear modeling tested whether increased IL-6:soluble IL-6 receptor ratio post-intervention was associated with decreased depressive symptom at weeks 1, 2, 4 and 6 for those randomized to whole-body hyperthermia. Twenty-six individuals were randomized to whole-body hyperthermia [n = 12; 75 % female; age = 37.9 years (SD = 15.3) or sham [n = 14; 57.1 % female; age = 41.1 years (SD = 12.5). When compared to the sham condition, active whole-body hyperthermia only increased the IL-6:soluble IL-6 receptor ratio post-treatment [F(3,72) = 11.73,p < .001], but not pre-intervention or at weeks 1 and 4. Using hierarchical linear modeling, increased IL-6:sIL-6R ratio following whole-body hyperthermia moderated depressive symptoms at weeks 1, 2, 4 and 6, such that increases in the IL-6:soluble IL-6 receptor ratio were associated with decreased depressive symptoms at weeks 1, 2, 4 and 6 for those receiving the active whole-body hyperthermia compared to sham treatment (B = -229.44, t = -3.82,p < .001). Acute activation of classical intereukin-6 signaling might emerge as a heretofore unrecognized novel mechanism that could be harnessed to expand the antidepressant armamentarium.

Comparison of ELISA with automated ECLIA for IL-6 determination in COVID-19 patients: An Italian real-life experience

Objectives

Coronavirus disease 2019 (COVID-19) has a wide spectrum of clinical severity. A cytokine storm is associated with COVID-19 severity. Of these, IL-6 is significantly associated with higher mortality and is also a marker for predicting disease prognosis. IL-6 may act as a target for therapeutics and, a blockade of IL-6 function by Tocilizumab has been described as a treatment of the inflammatory process COVID-19-related. This study aims to describe our experience comparing two different methods, in detail Human IL-6 Instant ELISA and the Elecsys IL-6 based on ECLIA, for the IL-6 assessment.

Design and methods

IL-6 levels from serum samples of 104 COVID-19 patients, admitted to the AOU Careggi (Hospital in Florence -Italy), were assessed by using the two above-mentioned methods, and the results were analysed through Passing-Bablok regression fit and Bland-Altman plot.

Results

The regression exhibited a linear relation between the methods with a regression equation (y = - 0.13 + 0.63 x; 95 % C.I. intercept = - 0.13 to 4.55; 95 % C.I. slope = 1.03 to 1.26 with R2 = 0.89, p > 0.05), showing a positive slope. The agreement of the two methods reported a bias of -25.0 pg/mL. Thus, the two methods correlate but do not agree in terms of numeric results.

Conclusions

The two assays showed good comparability. However, because of the extremely wide linear range of the ECLIA, its throughput and its capacity for immune profiling, it represents an interesting emerging technology in the immunology field.

Low-dose naltrexone and NAD+ for the treatment of patients with persistent fatigue symptoms after COVID-19

A subset of patients experiences persistent fatigue symptoms after COVID-19, and patients may develop long COVID, which is characterized by lasting systemic symptoms. No treatments for this condition have been validated and are urgently warranted. In this pilot study, we assessed whether treatment with low-dose naltrexone (LDN, 4.5 mg/day) and supplementation with NAD + through iontophoresis patches could improve fatigue symptoms and quality of life in 36 patients with persistent moderate/severe fatigue after COVID-19. We detected a significant increase from baseline in SF-36 survey scores after 12 weeks of treatment (mean total SF-36 score 36.5 [SD: 15.6] vs. 52.1 [24.8]; p < 0.0001), suggestive of improvement of quality of life. Furthermore, participants scored significantly lower on the Chalder fatigue scale after 12 weeks of treatment (baseline: 25.9 [4.6], 12 weeks: 17.4 [9.7]; p < 0.0001). We found a subset of 52 % of patients to be responders after 12 weeks of treatment. Treatment was generally safe, with mild adverse events previously reported for LDN, which could be managed with dose adjustments. The iontophoresis patches were associated with mild, short-lived skin irritation in 25 % of patients. Our data suggest treatment with LDN and NAD+ is safe and may be beneficial in a subset of patients with persistent fatigue after COVID-19. Larger randomized controlled trials will have to confirm our data and determine which patient subpopulations might benefit most from this strategy.

Inflammatory Response Associated with West Nile Neuroinvasive Disease: A Systematic Review

BACKGROUND

West Nile virus (WNV) infection is a seasonal arbovirosis with the potential to cause severe neurological disease. Outcomes of the infection from WNV depend on viral factors (e.g., lineage) and host-intrinsic factors (e.g., age, sex, immunocompromising conditions). Immunity is essential to control the infection but may also prove detrimental to the host. Indeed, the persistence of high levels of pro-inflammatory cytokines and chemokines is associated with the development of blood-brain barrier (BBB) damage. Due to the importance of the inflammatory processes in the development of West Nile neuroinvasive disease (WNND), we reviewed the available literature on the subject.

METHODS

According to the 2020 updated PRISMA guidelines, all peer-reviewed articles regarding the inflammatory response associated with WNND were included.

RESULTS

One hundred and thirty-six articles were included in the data analysis and sorted into three groups (in vitro on-cell cultures, in vivo in animals, and in humans). The main cytokines found to be increased during WNND were IL-6 and TNF-α. We highlighted the generally small quantity and heterogeneity of information about the inflammatory patterns associated with WNND.

CONCLUSIONS

Further studies are needed to understand the pathogenesis of WNND and to investigate the extent and the way the host inflammatory response either helps in controlling the infection or in worsening the outcomes. This might prove useful both for the development of target therapies and for the development of molecular markers allowing early identification of patients displaying an inflammatory response that puts them at a higher risk of developing neuroinvasive disease and who might thus benefit from early antiviral therapies.

CCL18, CHI3L1, ANG2, IL-6 systemic levels are associated with the extent of lung damage and radiomic features in SARS-CoV-2 infection

OBJECTIVE AND DESIGN

We aimed to identify cytokines whose concentrations are related to lung damage, radiomic features, and clinical outcomes in COVID-19 patients.

MATERIAL OR SUBJECTS

Two hundred twenty-six patients with SARS-CoV-2 infection and chest computed tomography (CT) images were enrolled.

METHODS

CCL18, CHI3L1/YKL-40, GAL3, ANG2, IP-10, IL-10, TNFα, IL-6, soluble gp130, soluble IL-6R were quantified in plasma samples using Luminex assays. The Mann-Whitney U test, the Kruskal-Wallis test, correlation and regression analyses were performed. Mediation analyses were used to investigate the possible causal relationships between cytokines, lung damage, and outcomes. AVIEW lung cancer screening software, pyradiomics, and XGBoost classifier were used for radiomic feature analyses.

RESULTS

CCL18, CHI3L1, and ANG2 systemic levels mainly reflected the extent of lung injury. Increased levels of every cytokine, but particularly of IL-6, were associated with the three outcomes: hospitalization, mechanical ventilation, and death. Soluble IL-6R showed a slight protective effect on death. The effect of age on COVID-19 outcomes was partially mediated by cytokine levels, while CT scores considerably mediated the effect of cytokine levels on outcomes. Radiomic-feature-based models confirmed the association between lung imaging characteristics and CCL18 and CHI3L1.

CONCLUSION

Data suggest a causal link between cytokines (risk factor), lung damage (mediator), and COVID-19 outcomes.

The analysis of low-dose glucocorticoid maintenance therapy in patients with primary nephrotic syndrome suffering from COVID-19

Objectives: This study aimed to describe the effects of low-dose (prednisolone acetate 2.5-7.5 mg/day) glucocorticoids (GCs) maintenance therapy in patients with primary nephrotic syndrome (NS) suffering from coronavirus disease 2019 (COVID-19). Methods: A single-center retrospective study of NS patients with COVID-19 infection in Zhongda Hospital Affiliated to Southeast University from 1 February 2022 to 31 March 2023 was conducted. All enrolled patients underwent renal biopsy for the pathological diagnosis and reached complete remission (CR) or near-CR before COVID-19 infection. According to the maintained therapy regimen, patients were divided into low-dose GCs group and non-GCs group. Results: A total of 125 patients were enrolled in the study. Their median age was 46.0 ± 15.6 years, and the median value of 24-h urine protein was 0.77 g. The majority of these patients received treatment for more than 6 months, with a significant portion achieving CR (29.6%) or near-CR (43.2%). The leading cause of NS was membranous nephropathy (52%). There were no significant differences in the baseline characteristics between low-dose GCs and non-GCs group. As compared to those in the non-GCs group, patients receiving low-dose GCs treatment showed less fatigue or muscle weakness, smell disorder, palpitations, decreased appetite, taste disorder, dizziness, sore throat or difficult to swallow and fever (p < 0.05). Moreover, patients in the low-dose GCs group were with higher median quality of life scores (85.0) than in the non-GCs group (p = 0.001). Further serum inflammatory factor analysis indicated that interleukin-6 (IL-6) levels in the non-GCs group were significantly higher than that in the low-dose GCs group (p < 0.05). Conclusion: Patients with NS in low-dose GCs maintenance therapy stage showed milder symptom, higher quality of life and decreased serum IL-6 levels compared to those, who were not on GCs maintenance therapy. These results suggest the beneficial effect of low-dose GCs therapy in NS patients with CR/near-CR suffering from COVID-19 infection.

Agranulocytosis and secondary infection related to JAK inhibitors and IL-6 receptor blockers: a disproportionality analysis using the US Food and drug administration adverse event reporting system

Background: Given that the fight against coronavirus disease 2019 (COVID-19) is not over, we aimed to explore the occurrence of agranulocytosis and infectious complications in patients with and without COVID-19 following immunoregulatory therapy based on real-world data. Methods: This was a retrospective disproportionality analysis based on the US Food and Drug Administration Adverse Event Reporting System (FAERS). All cases reported between the first quarter of 2004 and the fourth quarter of 2022 about Janus kinase inhibitors (baricitinib, tofacitinib, ruxolitinib) and interleukin-6 receptor blockers (tocilizumab, sarilumab) were collected. Disproportionality analyses were conducted by reporting odds ratio (ROR) and information component (IC). Results: A total of 211,363 cases were recognized from the FDA Adverse Event Reporting System database. Data analysis showed that tocilizumab (reporting odds ratio: 3.18, 95% CI: 3.18-3.29; information component: 1.37, 95% CI: 1.31-1.42), sarilumab (ROR: 1.64, 95% CI: 1.55-1.73; IC: 0.61, 95% CI: 0.43-0.79), baricitinib (ROR: 3.42, 95% CI: 3.19-3.67; IC: 1.43, 95% CI: 1.21-1.65), tofacitinib (ROR: 2.53, 95% CI: 2.49-2.57; IC: 1.11, 95% CI: 1.05-1.16), and ruxolitinib (ROR: 1.87, 95% CI: 1.83-1.91; IC: 0.77, 95% CI: 0.70-0.84) were all associated with secondary infection. The association in the combination group was higher than that in the monotherapy group (ROR: 4.69, 95% CI: 4.53-4.86; IC: 1.73, 95% CI: 1.62-1.84). As for agranulocytosis, tocilizumab (ROR: 1.61, 95% CI: 1.53-1.69; IC: 0.67, 95% CI: 0.50-0.84) and ruxolitinib (ROR: 2.32, 95% CI: 2.21-2.43; IC: 1.18, 95% CI: 1.02-1.33) showed the significant signals. The association was higher in the combination group than in the monotherapy group (ROR: 2.36, 95% CI: 2.15-2.58; IC: 1.20, 95% CI: 0.90-1.51). Secondary infection after treatment with tofacitinib (ROR: 1.37, 95% CI: 1.02-1.84), tocilizumab (ROR: 1.46, 95% CI: 1.01-2.09), and sarilumab (ROR: 2.46, 95% CI: 1.10-5.50) was reported more frequently in COVID-19 than in non-COVID-19 patients. Conclusion: Both Janus kinase inhibitors and interleukin-6 receptor blockers are significantly associated with secondary infection and agranulocytosis, and the combined treatment further increases the association. The correlation with secondary infection in patients treated with tofacitinib, tocilizumab, and sarilumab is higher in COVID-19 than in non-COVID-19 patients.

Unveiling COVID-19 Secrets: Harnessing Cytokines as Powerful Biomarkers for Diagnosis and Predicting Severity

Introduction

In coronavirus disease (COVID-19), inflammation takes center stage, with a cascade of cytokines released, contributing to both inflammation and lung damage. The objective of this study is to identify biomarkers for diagnosing and predicting the severity of COVID-19.

Materials and Methods

Cytokine levels were determined in the serum from venous blood samples collected from 100 patients with COVID-19 and 50 healthy controls. COVID-19 patients classified based on the Modified Early Warning (MEWS) score. Cytokine concentrations were determined with a multiplex ELISA kit (Bio-Plex Pro™ Human Cytokine Screening Panel).

Results

The concentrations of all analyzed cytokines were elevated in the serum of COVID-19 patients relative to the control group, but no significant differences were observed in interleukin-9 (IL-9) and IL-12 p70 levels. In addition, the concentrations of IL-1α, IL-1β, IL-1ra, IL-2Rα, IL-6, IL-12 p40, IL-18, and tumor necrosis factor alpha (TNFα) were significantly higher in symptomatic patients with accompanying pneumonia without respiratory failure (stage 2) than in asymptomatic/mildly symptomatic patients (stage 1).

Conclusion

The study revealed that IL-1ra, IL-2Rα, IL-6, IL-8, IL-12 p40, IL-16, and IL-18 levels serve as potential diagnostic biomarkers in COVID-19 patients. Furthermore, elevated IL-1α levels proved to be valuable in assessing the severity of COVID-19.

The impact of Sars-Cov-2 infection on the wound healing of cervical treatment in patients with squamous intraepithelial lesions: a retrospective cohort study

Objective

SARS-CoV-2 infection has been associated with an increase in inflammatory factors, a weakening of the immune system, and a potentially delay in wound healing following surgery or ablative treatment. In this retrospective cohort study, we aimed to investigate the impact of SARS-CoV-2 infection on wound healing following cervical treatment in patients with squamous intraepithelial lesions (SIL).

Method

From November 2022 to February 2023, patients with SIL who underwent cervical ablative treatment or loop electrosurgical excision procedure at the People's Hospital of Guangxi Zhuang Autonomous Region, China, were enrolled in the study. Of these, 29 patients who developed symptoms of SARS-CoV-2 infection and confirmed by an antigen test within one month after cervical treatment were included as experimental group, while the other 31 patients who received cervical treatment after recovering from SARS-CoV-2 infection were included in the control group. The cervical wound condition of all patients was documented using colposcopy immediately and one month after the procedure. Image J software was utilized to analyze the wound healing rate at one month post-treatment, and the wound healing status between two groups was compared. A vaginal discharge examination was performed before and one month after cervical treatment.

Results

No significant differences in age, severity, treatment, or time between groups. Experimental group had significantly lower healing rate 83.77(62.04, 97.09) % than control 98.64(97.10, 99.46)%，p < 0.001, and a higher scab non-shedding rate (24.14% vs. 3.22%, p = 0.024). Among patients who were infected with SARS-CoV-2 after undergoing cervical treatment, we observed 5 out of 7 patients (71.43%) contracted SARS-CoV-2 within 2 weeks after cervical treatment. No significant correlation was found between white blood cell count or leukocyte esterase in vaginal discharge and delayed wound healing of the cervix (p = 0.947 and 0.970, respectively).

Conclusion

SARS-CoV-2 infection may prolong the healing time of cervical treatment in patients with SIL. To minimize the risk of delayed healing, it's crucial for patients to avoid viral infections such as SARS-CoV-2 within the first month of treatment. Taking necessary precautions to prevent infection is essential for successful cervical treatment outcomes in patients with SIL.

In silico drug repurposing carvedilol and its metabolites against SARS-CoV-2 infection using molecular docking and molecular dynamic simulation approaches

The pandemic of coronavirus disease 2019 (COVID-19) caused by the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a significant impact on the economy and public health worldwide. Therapeutic options such as drugs and vaccines for this newly emerged disease are eagerly desired due to the high mortality. Using the U.S. Food and Drug Administration (FDA) approved drugs to treat a new disease or entirely different diseases, in terms of drug repurposing, minimizes the time and cost of drug development compared to the de novo design of a new drug. Drug repurposing also has some other advantages such as reducing safety evaluation to accelerate drug application on time. Carvedilol, a non-selective beta-adrenergic blocker originally designed to treat high blood pressure and manage heart disease, has been shown to impact SARS-CoV-2 infection in clinical observation and basic studies. Here, we applied computer-aided approaches to investigate the possibility of repurposing carvedilol to combat SARS-CoV-2 infection. The molecular mechanisms and potential molecular targets of carvedilol were identified by evaluating the interactions of carvedilol with viral proteins. Additionally, the binding affinities of in vivo metabolites of carvedilol with selected targets were evaluated. The docking scores for carvedilol and its metabolites with RdRp were - 10.0 kcal/mol, - 9.8 kcal/mol (1-hydroxyl carvedilol), - 9.7 kcal/mol (3-hydroxyl carvedilol), - 9.8 kcal/mol (4-hydroxyl carvedilol), - 9.7 kcal/mol (5-hydroxyl carvedilol), - 10.0 kcal/mol (8-hydroxyl carvedilol), and - 10.1 kcal/mol (O-desmethyl carvedilol), respectively. Using the molecular dynamics simulation (100 ns) method, we further confirmed the stability of formed complexes of RNA-dependent RNA polymerase (RdRp) and carvedilol or its metabolites. Finally, the drug-target interaction mechanisms that contribute to the complex were investigated. Overall, this study provides the molecular targets and mechanisms of carvedilol and its metabolites as repurposed drugs to fight against SARS-CoV-2 infection.

Dipeptidyl-peptidase 3 and IL-6: potential biomarkers for diagnostics in COVID-19 and association with pulmonary infiltrates

Coronavirus SARS-CoV-2 spread worldwide, causing a respiratory disease known as COVID-19. The aim of the present study was to examine whether Dipeptidyl-peptidase 3 (DPP3) and the inflammatory biomarkers IL-6, CRP, and leucocytes are associated with COVID-19 and able to predict the severity of pulmonary infiltrates in COVID-19 patients versus non-COVID-19 patients. 114 COVID-19 patients and 35 patients with respiratory infections other than SARS-CoV-2 were included in our prospective observational study. Blood samples were collected at presentation to the emergency department. 102 COVID-19 patients and 28 non-COVID-19 patients received CT imaging (19 outpatients did not receive CT imaging). If CT imaging was available, artificial intelligence software (CT Pneumonia Analysis) was used to quantify pulmonary infiltrates. According to the median of infiltrate (14.45%), patients who obtained quantitative CT analysis were divided into two groups (> median: 55 COVID-19 and nine non-COVID-19, ≤ median: 47 COVID-19 and 19 non-COVID-19). DPP3 was significantly elevated in COVID-19 patients (median 20.85 ng/ml, 95% CI 18.34-24.40 ng/ml), as opposed to those without SARS-CoV-2 (median 13.80 ng/ml, 95% CI 11.30-17.65 ng/ml; p < 0.001, AUC = 0.72), opposite to IL-6, CRP (each p = n.s.) and leucocytes (p < 0.05, but lower levels in COVID-19 patients). Regarding binary logistic regression analysis, higher DPP3 concentrations (OR = 1.12, p < 0.001) and lower leucocytes counts (OR = 0.76, p < 0.001) were identified as significant and independent predictors of SARS-CoV-2 infection, as opposed to IL-6 and CRP (each p = n.s.). IL-6 was significantly increased in patients with infiltrate above the median compared to infiltrate below the median both in COVID-19 (p < 0.001, AUC = 0.78) and in non-COVID-19 (p < 0.05, AUC = 0.81). CRP, DPP3, and leucocytes were increased in COVID-19 patients with infiltrate above median (each p < 0.05, AUC: CRP 0.82, DPP3 0.70, leucocytes 0.67) compared to infiltrate below median, opposite to non-COVID-19 (each p = n.s.). Regarding multiple linear regression analysis in COVID-19, CRP, IL-6, and leucocytes (each p < 0.05) were associated with the degree of pulmonary infiltrates, as opposed to DPP3 (p = n.s.). DPP3 showed the potential to be a COVID-19-specific biomarker. IL-6 might serve as a prognostic marker to assess the extent of pulmonary infiltrates in respiratory patients.

Transcriptional Profiling of SARS-CoV-2-Infected Calu-3 Cells Reveals Immune-Related Signaling Pathways

The COVID-19 disease, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), emerged in late 2019 and rapidly spread worldwide, becoming a pandemic that infected millions of people and caused significant deaths. COVID-19 continues to be a major threat, and there is a need to deepen our understanding of the virus and its mechanisms of infection. To study the cellular responses to SARS-CoV-2 infection, we performed an RNA sequencing of infected vs. uninfected Calu-3 cells. Total RNA was extracted from infected (0.5 MOI) and control Calu-3 cells and converted to cDNA. Sequencing was performed, and the obtained reads were quality-analyzed and pre-processed. Differential expression was assessed with the EdgeR package, and functional enrichment was performed in EnrichR for Gene Ontology, KEGG pathways, and WikiPathways. A total of 1040 differentially expressed genes were found in infected vs. uninfected Calu-3 cells, of which 695 were up-regulated and 345 were down-regulated. Functional enrichment analyses revealed the predominant up-regulation of genes related to innate immune response, response to virus, inflammation, cell proliferation, and apoptosis. These transcriptional changes following SARS-CoV-2 infection may reflect a cellular response to the infection and help to elucidate COVID-19 pathogenesis, in addition to revealing potential biomarkers and drug targets.

Antrodia cinnamomea May Interfere with the Interaction Between ACE2 and SARS-CoV-2 Spike Protein in vitro and Reduces Lung Inflammation in a Hamster Model of COVID-19

Purpose

Coronavirus disease 2019 (COVID-19) poses a global health challenge with widespread transmission. Growing concerns about vaccine side effects, diminishing efficacy, and religious-based hesitancy highlight the need for alternative pharmacological approaches. Our study investigates the impact of the ethanol extract of Antrodia cinnamomea (AC), a native medicinal fungus from Taiwan, on COVID-19 in both in vitro and in vivo contexts.

Methods

We measured the mRNA and protein levels of angiotensin-converting enzyme-2 (ACE2) in human lung cells using real-time reverse transcriptase-polymerase chain reaction and Western blotting, respectively. Additionally, we determined the enzymatic activity of ACE2 using the fluorogenic peptide substrate Mca-YVADAPK(Dnp)-OH. To assess the impact of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, we used SARS-CoV-2 pseudovirus infections in human embryonic kidney 293T cells expressing ACE2 to measure infection rates. Furthermore, we evaluated the in vivo efficacy of AC in mitigating COVID-19 by conducting experiments on hamsters infected with the Delta variant of SARS-CoV-2.

Results

AC effectively decreased ACE2 mRNA and protein levels, a critical host receptor for the SARS-CoV-2 spike protein, in human lung cells. It also prevented the spike protein from binding to human lung cells. Dehydrosulphurenic acid, an isolate from AC, directly inhibited ACE2 protease activity with an inhibitory constant of 1.53 µM. In vitro experiments showed that both AC and dehydrosulphurenic acid significantly reduced the infection rate of SARS-CoV-2 pseudovirus. In hamsters infected with the Delta variant of SARS-CoV-2, oral administration of AC reduced body weight loss and improved lung injury. Notably, AC also inhibited IL-1β expression in both macrophages and the lung tissues of SARS-CoV-2-infected hamsters.

Conclusion

AC shows potential as a nutraceutical for reducing the risk of SARS-CoV-2 infection by disrupting the interaction between ACE2 and the SARS-CoV-2 spike protein, and for preventing COVID-19-associated lung inflammation.

15-lipoxygenase and cyclooxygenase expression profile and their related modulators in COVID-19 infection

BACKGROUND

The role of the lipoxygenase (LOX) and cyclooxygenase (COX) enzymes in maintaining cellular homeostasis and regulating immune responses promoted us in this study to analyze the pattern of changes in 15-lipoxygenase and cyclooxygenase isoforms and their related cytokines in SARS-CoV-2 infection.

METHODS

15-LOX-1, 15-LOX-2, COX-1 and COX-2 gene expression levels were determined using qRT-PCR in nasopharynx specimens from patients with severe [N = 40] and non-severe [N = 40] confirmed SARS-CoV-2 infections and healthy controls. Circulating levels of lL-6, lL-10, PGE2, and IFN-γ were measured in patients and healthy controls using ELISA assay. The associations between the measured variables and the patient's clinic-pathological characteristics were assessed for all groups.

RESULTS

The expression level of 15-LOX-1 was elevated significantly in male patients with severe infection; although female patients showed a different expression profile. 15-LOX-2 expression level was considerably increased in male patients with severe infection; while changes in its expression remained inconclusive in female patients. The relationship between 15-LOX expression and the male gender was prominent. Both COX isoforms expression showed elevation in male and female patients that were correlated with disease severity. The simultaneous increase in lL-6, PGE2 and IFN-γ levels also decrease in lL-10 in patients with severe infection indicating the possible regulatory network related to the COX and 15-LOX enzymes in the output of the SARS-CoV-2 infection.

CONCLUSION

The results of this study determined the pattern of possible changes in key enzymes of prostaglandin and eicosanoids synthesis pathway and their mediators, which can be helpful in mapping the SARS-CoV-2 pathogenicity and pharmaceutical approaches.

Mesenchymal Stem Cells in the Treatment of COVID-19

Since the emergence of the coronavirus disease 2019 (COVID-19) pandemic, many lives have been tragically lost to severe infections. The COVID-19 impact extends beyond the respiratory system, affecting various organs and functions. In severe cases, it can progress to acute respiratory distress syndrome (ARDS) and multi-organ failure, often fueled by an excessive immune response known as a cytokine storm. Mesenchymal stem cells (MSCs) have considerable potential because they can mitigate inflammation, modulate immune responses, and promote tissue regeneration. Accumulating evidence underscores the efficacy and safety of MSCs in treating severe COVID-19 and ARDS. Nonetheless, critical aspects, such as optimal routes of MSC administration, appropriate dosage, treatment intervals, management of extrapulmonary complications, and potential pediatric applications, warrant further exploration. These research avenues hold promise for enriching our understanding and refining the application of MSCs in confronting the multifaceted challenges posed by COVID-19.

Validation of sTREM-1 and IL-6 based algorithms for outcome prediction of COVID-19

BACKGROUND

A prospective observational cohort study of COVID-19 patients in a single Emergency Department (ED) showed that sTREM-1- and IL-6-based algorithms were highly predictive of adverse outcome (Van Singer et al. J Allergy Clin Immunol 2021). We aim to validate the performance of these algorithms at ED presentation.

METHODS

This multicentric prospective observational study of PCR-confirmed COVID-19 adult patients was conducted in the ED of three Swiss hospitals. Data of the three centers were retrospectively completed and merged. We determined the predictive accuracy of the sTREM-1-based algorithm for 30-day intubation/mortality. We also determined the performance of the IL-6-based algorithm using data from one center for 30-day oxygen requirement.

RESULTS

373 patients were included in the validation cohort, 139 (37%) in Lausanne, 93 (25%) in St.Gallen and 141 (38%) in EOC. Overall, 18% (93/373) patients died or were intubated by day 30. In Lausanne, 66% (92/139) patients required oxygen by day 30. The predictive accuracy of sTREM-1 and IL-6 were similar compared to the derivation cohort. The sTREM-1-based algorithm confirmed excellent sensitivity (90% versus 100% in the derivation cohort) and negative predictive value (94% versus 100%) for 30-day intubation/mortality. The IL-6-based algorithm performance was acceptable with a sensitivity of 85% versus 98% in the derivation cohort and a negative predictive value of 60% versus 92%.

CONCLUSION

The sTREM-1 algorithm demonstrated good reproducibility. A prospective randomized controlled trial, comparing outcomes with and without the algorithm, is necessary to assess its safety and impact on hospital and ICU admission rates. The IL-6 algorithm showed acceptable validity in a single center and need additional validation before widespread implementation.

Recent Progresses in Optical Biosensors for Interleukin 6 Detection

Interleukin 6 (IL-6) is pleiotropic cytokine with pathological pro-inflammatory effects in various acute, chronic and infectious diseases. It is involved in a variety of biological processes including immune regulation, hematopoiesis, tissue repair, inflammation, oncogenesis, metabolic control, and sleep. Due to its important role as a biomarker of many types of diseases, its detection in small amounts and with high selectivity is of particular importance in medical and biological fields. Laboratory methods including enzyme-linked immunoassays (ELISAs) and chemiluminescent immunoassays (CLIAs) are the most common conventional methods for IL-6 detection. However, these techniques suffer from the complexity of the method, the expensiveness, and the time-consuming process of obtaining the results. In recent years, too many attempts have been conducted to provide simple, rapid, economical, and user-friendly analytical approaches to monitor IL-6. In this regard, biosensors are considered desirable tools for IL-6 detection because of their special features such as high sensitivity, rapid detection time, ease of use, and ease of miniaturization. In this review, current progresses in different types of optical biosensors as the most favorable types of biosensors for the detection of IL-6 are discussed, evaluated, and compared.

The role of cell death in SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), showing high infectiousness, resulted in an ongoing pandemic termed coronavirus disease 2019 (COVID-19). COVID-19 cases often experience acute respiratory distress syndrome, which has caused millions of deaths. Apart from triggering inflammatory and immune responses, many viral infections can cause programmed cell death in infected cells. Cell death mechanisms have a vital role in maintaining a suitable environment to achieve normal cell functionality. Nonetheless, these processes are dysregulated, potentially contributing to disease pathogenesis. Over the past decades, multiple cell death pathways are becoming better understood. Growing evidence suggests that the induction of cell death by the coronavirus may significantly contributes to viral infection and pathogenicity. However, the interaction of SARS-CoV-2 with cell death, together with its associated mechanisms, is yet to be elucidated. In this review, we summarize the existing evidence concerning the molecular modulation of cell death in SARS-CoV-2 infection as well as viral-host interactions, which may shed new light on antiviral therapy against SARS-CoV-2.

NLRP3 inflammasome and interleukin-1 contributions to COVID-19-associated coagulopathy and immunothrombosis

Immunothrombosis-immune-mediated activation of coagulation-is protective against pathogens, but excessive immunothrombosis can result in pathological thrombosis and multiorgan damage, as in severe coronavirus disease 2019 (COVID-19). The NACHT-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome produces major proinflammatory cytokines of the interleukin (IL)-1 family, IL-1β and IL-18, and induces pyroptotic cell death. Activation of the NLRP3 inflammasome pathway also promotes immunothrombotic programs including release of neutrophil extracellular traps and tissue factor by leukocytes, and prothrombotic responses by platelets and the vascular endothelium. NLRP3 inflammasome activation occurs in patients with COVID-19 pneumonia. In preclinical models, NLRP3 inflammasome pathway blockade restrains COVID-19-like hyperinflammation and pathology. Anakinra, recombinant human IL-1 receptor antagonist, showed safety and efficacy and is approved for the treatment of hypoxaemic COVID-19 patients with early signs of hyperinflammation. The non-selective NLRP3 inhibitor colchicine reduced hospitalization and death in a subgroup of COVID-19 outpatients but is not approved for the treatment of COVID-19. Additional COVID-19 trials testing NLRP3 inflammasome pathway blockers are inconclusive or ongoing. We herein outline the contribution of immunothrombosis to COVID-19-associated coagulopathy, and review preclinical and clinical evidence suggesting an engagement of the NLRP3 inflammasome pathway in the immunothrombotic pathogenesis of COVID-19. We also summarize current efforts to target the NLRP3 inflammasome pathway in COVID-19, and discuss challenges, unmet gaps, and the therapeutic potential that inflammasome-targeted strategies may provide for inflammation-driven thrombotic disorders including COVID-19.

Immunotherapies in chronic pain through modulation of neuroimmune interactions

It is generally believed that immune activation can elicit pain through production of inflammatory mediators that can activate nociceptive sensory neurons. Emerging evidence suggests that immune activation may also contribute to the resolution of pain by producing distinct pro-resolution/anti-inflammatory mediators. Recent research into the connection between the immune and nervous systems has opened new avenues for immunotherapy in pain management. This review provides an overview of the most utilized forms of immunotherapies (e.g., biologics) and highlight their potential for immune and neuronal modulation in chronic pain. Specifically, we discuss pain-related immunotherapy mechanisms that target inflammatory cytokine pathways, the PD-L1/PD-1 pathway, and the cGAS/STING pathway. This review also highlights cell-based immunotherapies targeting macrophages, T cells, neutrophils and mesenchymal stromal cells for chronic pain management.

COVID-19 in Pediatric Intensive Care Units in Poland, PAPITCO-19 Study (Polish Analysis of PICU Trends during COVID-19)

BACKGROUND

Children suffering from COVID-19 constitute about 10% of the entire population infected with the virus. In most of them, we observe asymptomatic or mild courses; however, about 1% of affected children require a stay in a paediatric intensive care unit (PICU) due to the course of the disease becoming severely life-threatening. The risk of respiratory failure, as with adults, is associated with the coexistence of concomitant diseases. The aim of our study was to analyse patients admitted to PICUs due to the severe course of their SARS-CoV-2 infection. We studied epidemiological and laboratory parameters, as well as the endpoint (survival or death).

METHODS

A retrospective multi-centre study, the analysis covered all children with a confirmed diagnosis of SARS-CoV-2 virus infection who were admitted to PICUs in the period from November 2020 to August 2021. We studied epidemiological and laboratory parameters, as well as the endpoint (survival or death).

RESULTS

The study analysed 45 patients (0.075% of all children hospitalised in Poland due to COVID-19 at that time). Mortality calculated in the entire study group was 40% (n = 18). Statistically significant differences between the compared groups (survived and died) concerned the parameters of the respiratory system. Lung Injury Score and the Paediatric Sequential Organ Failure Assessment were used. A significant correlation between disease severity and the patient's prognosis was shown by the liver function parameter AST (p = 0.028). During the analysis of patients requiring mechanical ventilation and assuming survival as the primary outcome, a significantly higher oxygen index on the first day of hospitalisation, lower pSOFA scores and lower AST levels (p: 0.007; 0.043; 0.020; 0.005; 0.039, respectively) were found.

CONCLUSIONS

As with adults, children with comorbidities are most frequently at risk of severe SARS-CoV-2 infection. Increasing symptoms of respiratory failure, the need for mechanical ventilation and persistently high values of aspartate aminotransferase are indicators of poor prognosis.

Cytokine Storm Syndromes in Pediatric Patients

Cytokine storm syndromes (CSS) represent a diverse group of disorders characterized by severe overactivation of the immune system. In the majority of patients, CSS arise from a combination of host factors, including genetic risk and predisposing conditions, and acute triggers such as infections. CSS present differently in adults than in children, who are more likely to present with monogenic forms of these disorders. Individual CSS are rare, but in aggregate represent an important cause of severe illness in both children and adults. We present 3 rare, illustrative cases of CSS in pediatric patients that describe the spectrum of CSS.

Development and external validation of a prognostic tool for nonsevere COVID-19 inpatients

To develop a machine learning model and nomogram to predict the probability of persistent virus shedding (PVS) in hospitalized patients with coronavirus disease 2019 (COVID-19), the clinical symptoms and signs, laboratory parameters, cytokines, and immune cell data of 429 patients with nonsevere COVID-19 were retrospectively reviewed. Two models were developed using the Akaike information criterion (AIC). The performance of these two models was analyzed and compared by the receiver operating characteristic (ROC) curve, calibration curve, net reclassification index (NRI), and integrated discrimination improvement (IDI). The final model included the following independent predictors of PVS: sex, C-reactive protein (CRP) level, interleukin-6 (IL-6) level, the neutrophil-lymphocyte ratio (NLR), monocyte count (MC), albumin (ALB) level, and serum potassium level. The model performed well in both the internal validation (corrected C-statistic = 0.748, corrected Brier score = 0.201) and external validation datasets (corrected C-statistic = 0.793, corrected Brier score = 0.190). The internal calibration was very good (corrected slope = 0.910). The model developed in this study showed high discriminant performance in predicting PVS in nonsevere COVID-19 patients. Because of the availability and accessibility of the model, the nomogram designed in this study could provide a useful prognostic tool for clinicians and medical decision-makers.

PGLYRP1-mIgG2a-Fc inhibits macrophage activation via AKT/NF-κB signaling and protects against fatal lung injury during bacterial infection

Severe bacterial pneumonia leads to acute respiratory distress syndrome (ARDS), with a high incidence rate and mortality. It is well-known that continuous and dysregulated macrophage activation is vital for aggravating the progression of pneumonia. Here, we designed and produced an antibody-like molecule, peptidoglycan recognition protein 1-mIgG2a-Fc (PGLYRP1-Fc). PGLYRP1 was fused to the Fc region of mouse IgG2a with high binding to macrophages. We demonstrated that PGLYRP1-Fc ameliorated lung injury and inflammation in ARDS, without affecting bacterial clearance. Besides, PGLYRP1-Fc reduced AKT/nuclear factor kappa-B (NF-κB) activation via the Fc segment bound Fc gamma receptor (FcγR)-dependent mechanism, making macrophage unresponsive, and immediately suppressed proinflammatory response upon bacteria or lipopolysaccharide (LPS) stimulus in turn. These results confirm that PGLYRP1-Fc protects against ARDS by promoting host tolerance with reduced inflammatory response and tissue damage, irrespective of the host's pathogen burden, and provide a promising therapeutic strategy for bacterial infection.

Host-Based Treatments for Severe COVID-19

COVID-19 has been a global health problem since 2020. There are different spectrums of manifestation of this disease, ranging from asymptomatic to extremely severe forms requiring admission to intensive care units and life-support therapies, mainly due to severe pneumonia. The progressive understanding of this disease has allowed researchers and clinicians to implement different therapeutic alternatives, depending on both the severity of clinical involvement and the causative molecular mechanism that has been progressively explored. In this review, we analysed the main therapeutic options available to date based on modulating the host inflammatory response to SARS-CoV-2 infection in patients with severe and critical illness. Although current guidelines are moving toward a personalised treatment approach titrated on the timing of presentation, disease severity, and laboratory parameters, future research is needed to identify additional biomarkers that can anticipate the disease course and guide targeted interventions on an individual basis.

Innate immune evasion strategies of SARS-CoV-2

SARS-CoV-2, the virus responsible for the COVID-19 pandemic, has been associated with substantial global morbidity and mortality. Despite a tropism that is largely confined to the airways, COVID-19 is associated with multiorgan dysfunction and long-term cognitive pathologies. A major driver of this biology stems from the combined effects of virus-mediated interference with the host antiviral defences in infected cells and the sensing of pathogen-associated material by bystander cells. Such a dynamic results in delayed induction of type I and III interferons (IFN-I and IFN-III) at the site of infection, but systemic IFN-I and IFN-III priming in distal organs and barrier epithelial surfaces, respectively. In this Review, we examine the relationship between SARS-CoV-2 biology and the cellular response to infection, detailing how antagonism and dysregulation of host innate immune defences contribute to disease severity of COVID-19.

Experimental venous thrombus resolution is driven by IL-6 mediated monocyte actions

Deep venous thrombosis and residual thrombus burden correlates with circulating IL-6 levels in humans. To investigate the cellular source and role of IL-6 in thrombus resolution, Wild type C57BL/6J (WT), and IL-6-/- mice underwent induction of VT via inferior vena cava (IVC) stenosis or stasis. Vein wall (VW) and thrombus were analyzed by western blot, immunohistochemistry, and flow cytometry. Adoptive transfer of WT bone marrow derived monocytes was performed into IL6-/- mice to assess for rescue. Cultured BMDMs from WT and IL-6-/- mice underwent quantitative real time PCR and immunoblotting for fibrinolytic factors and matrix metalloproteinase activity. No differences in baseline coagulation function or platelet function were found between WT and IL-6-/- mice. VW and thrombus IL-6 and IL-6 leukocyte-specific receptor CD126 were elevated in a time-dependent fashion in both VT models. Ly6Clo Mo/MØ were the predominant leukocyte source of IL-6. IL-6-/- mice demonstrated larger, non-resolving stasis thrombi with less neovascularization, despite a similar number of monocytes/macrophages (Mo/MØ). Adoptive transfer of WT BMDM into IL-6-/- mice undergoing stasis VT resulted in phenotype rescue. Human specimens of endophlebectomized tissue showed co-staining of Monocyte and IL-6 receptor. Thrombosis matrix analysis revealed significantly increased thrombus fibronectin and collagen in IL-6-/- mice. MMP9 activity in vitro depended on endogenous IL-6 expression in Mo/MØ, and IL-6-/- mice exhibited stunted matrix metalloproteinase activity. Lack of IL-6 signaling impairs thrombus resolution potentially via dysregulation of MMP-9 leading to impaired thrombus recanalization and resolution. Restoring or augmenting monocyte-mediated IL-6 signaling in IL-6 deficient or normal subjects, respectively, may represent a non-anticoagulant target to improve thrombus resolution.

Pattern of antibiotic use and bacterial co-infection in hospitalized Covid-19 patients

Background

There is evidence that bacterial co-infection in respiratory viruses leads to morbidity and mortality. Patients with decreased immunity are prone to bacterial co-infection. A lack of judicious use of antibiotics leads to the spread of multi-drug resistant bacteria (MDR) that have a long-term negative impact. In this study, we attempted to observe the pattern of antibacterial use and its impact on secondary bacterial infection.

Methods

An observational study was conducted at Alexandria Main University Hospital (AMUH) (Alexandria University) from June 2021- February 2022. Study participants were admitted to the Intensive Care Unit (ICU) with confirmed Covid-19 (by Polymerase Chain Reaction (PCR) and Computed tomography (CT) scan). The following data was collected (Demographic, clinical, and laboratory data).In this study, the Pattern of antibiotic use as well as the occurrence of secondary bacterial infections were reported.

Results

Among 121 patients included in the present study, all received antibiotics empirically. Upon admission (19.8%) showed urinary tract infection, (11.5%) had bloodstream infection, and (57.7%) had respiratory tract infection. After 10 days secondary bacterial infection occurred in 38 patients (61.2%) with (24.1%) Urinary tract infection (UTI), (12.9%) Bloodstream infection (BSI), and (72.2%) respiratory tract infection. The respiratory sample size was (45) patients due to Infection Control (IC) restrictions on the aerosol-producing procedure.

Conclusion

Upon admission, all patients received broad-spectrum antibiotics while the incidence of bacterial co-infection was low.

Antiviral Potential of Small Molecules Cordycepin, Thymoquinone, and N6, N6-Dimethyladenosine Targeting SARS-CoV-2 Entry Protein ADAM17

COVID-19 is an acute respiratory disease caused by SARS-CoV-2 that has spawned a worldwide pandemic. ADAM17 is a sheddase associated with the modulation of the receptor ACE2 of SARS-CoV-2. Studies have revealed that malignant phenotypes of several cancer types are closely relevant to highly expressed ADAM17. However, ADAM17 regulation in SARS-CoV-2 invasion and its role on small molecules are unclear. Here, we evaluated the ADAM17 inhibitory effects of cordycepin (CD), thymoquinone (TQ), and N6, N6-dimethyladenosine (m⁶₂A), on cancer cells and predicted the anti-COVID-19 potential of the three compounds and their underlying signaling pathways by network pharmacology. It was found that CD, TQ, and m⁶₂A repressed the ADAM17 expression upon different cancer cells remarkably. Moreover, CD inhibited GFP-positive syncytia formation significantly, suggesting its potential against SARS-CoV-2. Pharmacological analysis by constructing CD-, TQ-, and m⁶₂A-based drug-target COVID-19 networks further indicated that ADAM17 is a potential target for anti-COVID-19 therapy with these compounds, and the mechanism might be relevant to viral infection and transmembrane receptors-mediated signal transduction. These findings imply that ADAM17 is of potentially medical significance for cancer patients infected with SARS-CoV-2, which provides potential new targets and insights for developing innovative drugs against COVID-19.

Influence of Vitamin A supplementation on inflammatory biomarkers in adults: a systematic review and meta-analysis of randomized clinical trials

Vitamin A is an anti-oxidant which has been presumed to act as an anti-infective vitamin in many studies. This study aimed to evaluate the association between vitamin A supplementation and c-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) levels in randomized control trials (RCTs) studies on adults. A systematic search was performed on databases including PUBMED, SCOPUS, and the Cochrane library. The studies included were considered for data extraction and subsequently assessed for effect. Weighted mean differences (WMD) and 95% confidence intervals (CIs) were evaluated. Among 13,219 articles 13 studies were included for analysis of CRP and TNF-α, as well as 9 studies included for IL-6 in quality and quantity. The pooled WMD analysis of CRP demonstrated that vitamin A supplementation significantly increased CRP concentration with (WMD: 0.84 mg/L; 95% CI 0.29-1.39, I² = 0.96.2% and p value < 0.003). However, there was no significant correlation between vitamin A supplementation and lower plasma TNF-α (p < 0.45)). Subgroup analysis by dosage demonstrate significant association between vitamin A supplementation and IL-6 in dosage with 50,000 with (WMD: - 1.53 mg/L; 95% CI - 2.36 to - 0.71, p value < 0.00001) as well as a negative significant association was seen at 44 weeks of supplementation with 50,000 IU/day retinyl palmitate and TNF-a in chronic hepatitis B conditions with (- 0.94 (- 1.19, - 0.69) p < 0.0001). The result of this study demonstrates that supplementation of vitamin A at low and high dosages for short and long durations increases the CRP plasma concentrations on adults and vitamin A supplementation decreases the TNF-α concentrations in chronic hepatitis B on adults. Therefore, there is an inverse association between vitamin A supplementation and plasma and fecal IL-6 concentrations in many infection conditions.

Distinct Immune Phenotypes and Cytokine Profiles in Children with Differing Severity of COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) is usually mild and self-limited in children. However, a few Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infections in children may progress to severe disease with respiratory distress or can result in a multisystem inflammatory syndrome (MIS-C) associated with COVID-19. The immune mechanisms for these differential clinical outcomes are largely unknown.

METHODS

A prospective cohort study was performed to analyze the laboratory parameters, antibody response, immune phenotypes and cytokine profiles of 51 children with different clinical presentations of COVID-19.

RESULTS

We found that the absolute lymphocyte counts gradually decreased with disease severity. Furthermore, SARS-CoV-2 IgG levels in the acute phase and convalescence were not significantly different in patients with different disease severity. A decrease in CD3 + , CD4 + and CD8 + T cells was observed as disease severity increased. Both CD4 + and CD8 + T cells were activated in children with COVID-19, but no difference in the percentage of HLADR + -expressing cells was detected across the severity groups. In contrast, MIS-C patients exhibited augmented exhausted effector memory CD8 + T cells. Interestingly, the cytokine profile in sera of moderate/severe and MIS-C patients revealed an increase in anti-inflammatory IL-1RA and a suppression of tumor necrosis factor-α, RANTES, eotaxin and PDGF-BB. MIS-C patients also exhibited augmented IL-1β.

CONCLUSIONS

We report distinct immune profiles dependent on severity in pediatric COVID-19 patients. Further investigation in a larger population will help unravel the immune mechanisms underlying pediatric COVID-19.

Clinical and laboratory findings following transplantation of allogeneic adipose-derived mesenchymal stromal cells in knee osteoarthritis, a brief report

BACKGROUND

Mesenchymal stromal cells (MSCs) injection has been proposed as an innovative treatment for knee osteoarthritis (KOA). Since, allogeneic MSCs can be available as off-the-shelf products, they are preferable in regenerative medicine. Among different sources for MSCs, adipose-derived MSCs (AD-MSCs) appear to be more available.

METHODS

Three patients with KOA were enrolled in this study. A total number of 100 × 10⁶ AD-MSCs was injected intra-articularly, per affected knee. They were followed up for 6 months by the assessment of clinical outcomes, magnetic resonance imaging (MRI), and serum inflammatory biomarkers.

RESULTS

The primary outcome of this study was safety and feasibility of allogeneic AD-MSCs injection during the 6 months follow-up. Fortunately, no serious adverse events (SAEs) were reported. Assessment of secondary outcomes of visual analogue scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and knee osteoarthritis outcome score (KOOS) indicated improvement in all patients. Comparison between baseline and endpoint findings of MRI demonstrated a slight improvement in two patients. In addition, decrease in serum cartilage oligomeric matrix protein (COMP) and hyaluronic acid (HA) indicated the possibility of reduced cartilage degeneration. Moreover, quantification of serum interleukin-10 (IL-10) and interleukin-6 (IL-6) levels indicated that the host immune system immunomodulated after infusion of AD-MSCs.

CONCLUSION

Intra-articular injection of AD-MSCs is safe and could be effective in cartilage regeneration in KOA. Preliminary assessment after six-month follow-up suggests the potential efficacy of this intervention which would need to be confirmed in randomized controlled trials on a larger population.

TRIAL REGISTRATION

This study was registered in the Iranian registry of clinical trials (https://en.irct.ir/trial/46) in 24 April 2018 with identifier IRCT20080728001031N23.

The IgG glycome of SARS-CoV-2 infected individuals reflects disease course and severity

Immunoglobulin G (IgG) antibodies play an important role in the immune response against viruses such as SARS-CoV-2. As the effector functions of IgG are modulated by N-glycosylation of the Fc region, the structure and possible function of the IgG N-glycome has been under investigation in relation to divergent COVID-19 disease courses. Through LC-MS analysis we studied both total IgG1 and spike protein-specific IgG1 Fc glycosylation of 129 German and 163 Brazilian COVID-19 patients representing diverse patient populations. We found that hospitalized COVID-19 patients displayed decreased levels of total IgG1 bisection and galactosylation and lowered anti-S IgG1 fucosylation and bisection as compared to mild outpatients. Anti-S IgG1 glycosylation was dynamic over the disease course and both anti-S and total IgG1 glycosylation were correlated to inflammatory markers. Further research is needed to dissect the possible role of altered IgG glycosylation profiles in (dys)regulating the immune response in COVID-19.

Interleukin-1 and the NLRP3 inflammasome in COVID-19: Pathogenetic and therapeutic implications

A hyperinflammatory response during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection crucially worsens clinical evolution of coronavirus disease 2019 (COVID-19). The interaction between SARS-CoV-2 and angiotensin-converting enzyme 2 (ACE2) triggers the activation of the NACHT, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome. Enhanced inflammasome activity has been associated with increased disease severity and poor prognosis. Evidence suggests that inflammasome activation and interleukin-1β (IL-1β) release aggravate pulmonary injury and induce hypercoagulability, favoring progression to respiratory failure and widespread thrombosis eventually leading to multiorgan failure and death. Observational studies with the IL-1 blockers anakinra and canakinumab provided promising results. In the SAVE-MORE trial, early treatment with anakinra significantly shortened hospital stay and improved survival in patients with moderate-to-severe COVID-19. In this review, we summarize current evidence supporting the pathogenetic role of the NLRP3 inflammasome and IL-1β in COVID-19, and discuss clinical trials testing IL-1 inhibition in COVID-19.

Roles of Interleukin-6-mediated immunometabolic reprogramming in COVID-19 and other viral infection-associated diseases

Interleukin-6 (IL-6) is a highly pleiotropic glycoprotein factor that can modulate innate and adaptive immunity as well as various aspects of metabolism, including glycolysis, fatty acid oxidation and oxidative phosphorylation. Recently, the expression and release of IL-6 is shown to be significantly increased in numerous diseases related to virus infection, and this increase is positively correlated with the disease severity. Immunity and metabolism are two highly integrated and interdependent systems, the balance between them plays a pivotal role in maintaining body homeostasis. IL-6-elicited inflammatory response is found to be closely associated with metabolic disorder in patients with viral infection. This brief review summarizes the regulatory role of IL-6 in immunometabolic reprogramming among seven viral infection-associated diseases.

Inflammatory pathways in COVID‐19: Mechanism and therapeutic interventions

The 2019 coronavirus disease (COVID‐19) pandemic has become a global crisis. In the immunopathogenesis of COVID‐19, SARS‐CoV‐2 infection induces an excessive inflammatory response in patients, causing an inflammatory cytokine storm in severe cases. Cytokine storm leads to acute respiratory distress syndrome, pulmonary and other multiorgan failure, which is an important cause of COVID‐19 progression and even death. Among them, activation of inflammatory pathways is a major factor in generating cytokine storms and causing dysregulated immune responses, which is closely related to the severity of viral infection. Therefore, elucidation of the inflammatory signaling pathway of SARS‐CoV‐2 is important in providing otential therapeutic targets and treatment strategies against COVID‐19. Here, we discuss the major inflammatory pathways in the pathogenesis of COVID‐19, including induction, function, and downstream signaling, as well as existing and potential interventions targeting these cytokines or related signaling pathways. We believe that a comprehensive understanding of the regulatory pathways of COVID‐19 immune dysregulation and inflammation will help develop better clinical therapy strategies to effectively control inflammatory diseases, such as COVID‐19.

Characterization of the pathogenesis and immune response to a highly virulent Edwardsiella tarda strain responsible for mass mortality in the hybrid snakehead (Channa maculate ♀ × Channa argus ♂)

Edwardsiella tarda is reported as the causative agent of the systemic disease Edwardsiellosis in fish, which lead to huge economic losses in aquaculture. The pathogenicity and immune response to a highly virulent E. tarda isolate responsible for mass mortality in hybrid snakehead were performed. After species identification, morphology and virulence gene detection of Edwardsiella isolated from hybrid snakehead, the pathogenicity of the strain and histopathological changes in infected fish were analyzed. The infected fish exhibited typical acute hemorrhagic symptoms and enlarged internal organs. Histopathology revealed that the liver, spleen, kidney and intestinal tissues of diseased fish exhibited marked inflammatory with vacuolar degeneration and cell necrosis. Subsequently, humoral immune factors such as superoxide dismutase, lysozyme and acid phosphatase activities were detected as serum indicators, and real-time quantitative PCR was used to investigate immune-related genes (STAT1, HSP70, IgM, IL-6, IL-8, TRAF2, CD40, HLA-DMA and LCK) expression patterns in liver, spleen and head kidney. The results showed that these enzyme activity indicators and immune-related gene expression were significantly activated compared with healthy fish. These data provide insight into the pathogenic mechanisms and host immune responses of E. tarda, which could be useful for the future prevention and treatment of Edwardsiellosis in fish.

Cell deaths: Involvement in the pathogenesis and intervention therapy of COVID-19

The current pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has dramatically influenced various aspects of the world. It is urgent to thoroughly study pathology and underlying mechanisms for developing effective strategies to prevent and treat this threatening disease. It is universally acknowledged that cell death and cell autophagy are essential and crucial to maintaining host homeostasis and participating in disease pathogenesis. At present, more than twenty different types of cell death have been discovered, some parts of which have been fully understood, whereas some of which need more investigation. Increasing studies have indicated that cell death and cell autophagy caused by coronavirus might play an important role in virus infection and pathogenicity. However, the knowledge of the interactions and related mechanisms of SARS-CoV-2 between cell death and cell autophagy lacks systematic elucidation. Therefore, in this review, we comprehensively delineate how SARS-CoV-2 manipulates diverse cell death (including apoptosis, necroptosis, pyroptosis, ferroptosis, and NETosis) and cell autophagy for itself benefits, which is simultaneously involved in the occurrence and progression of COVID-19, aiming to provide a reasonable basis for the existing interventions and further development of novel therapies.

Possible Role of Matrix Metalloproteinases and TGF-β in COVID-19 Severity and Sequelae

The costs of coronavirus disease 2019 (COVID-19) are devastating. With millions of deaths worldwide, specific serological biomarkers, antiviral agents, and novel therapies are urgently required to reduce the disease burden. For these purposes, a profound understanding of the pathobiology of COVID-19 is mandatory. Notably, the study of immunity against other respiratory infections has generated reference knowledge to comprehend the paradox of the COVID-19 pathogenesis. Past studies point to a complex interplay between cytokines and other factors mediating wound healing and extracellular matrix (ECM) remodeling that results in exacerbated inflammation, tissue injury, severe manifestations, and a sequela of respiratory infections. This review provides an overview of the immunological process elicited after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Also, we analyzed available data about the participation of matrix metalloproteinases (MMPs) and transforming growth factor-beta (TGF-β) in immune responses of the lungs. Furthermore, we discuss their possible implications in severe COVID-19 and sequela, including pulmonary fibrosis, and remark on the potential of these molecules as biomarkers for diagnosis, prognosis, and treatment of convalescent COVID-19 patients. Our review provides a theoretical framework for future research aimed to discover molecular hallmarks that, combined with clinical features, could serve as therapeutic targets and reliable biomarkers of the different clinical forms of COVID-19, including convalescence.

The Role of Cytochrome P450 Enzymes in COVID-19 Pathogenesis and Therapy

Coronavirus disease 2019 (COVID-19) has become a new public health crisis threatening the world. Dysregulated immune responses are the most striking pathophysiological features of patients with severe COVID-19, which can result in multiple-organ failure and death. The cytochrome P450 (CYP) system is the most important drug metabolizing enzyme family, which plays a significant role in the metabolism of endogenous or exogenous substances. Endogenous CYPs participate in the biosynthesis or catabolism of endogenous substances, including steroids, vitamins, eicosanoids, and fatty acids, whilst xenobiotic CYPs are associated with the metabolism of environmental toxins, drugs, and carcinogens. CYP expression and activity are greatly affected by immune response. However, changes in CYP expression and/or function in COVID-19 and their impact on COVID-19 pathophysiology and the metabolism of therapeutic agents in COVID-19, remain unclear. In this analysis, we review current evidence predominantly in the following areas: firstly, the possible changes in CYP expression and/or function in COVID-19; secondly, the effects of CYPs on the metabolism of arachidonic acid, vitamins, and steroid hormones in COVID-19; and thirdly, the effects of CYPs on the metabolism of therapeutic COVID-19 drugs.

Human Challenge Studies with Coronaviruses Old and New

Coronavirus infections have been known to cause disease in animals since as early as the 1920s. However, only seven coronaviruses capable of causing human disease have been identified thus far. These Human Coronaviruses (HCoVs) include the causes of the common cold, but more recent coronaviruses that have emerged (i.e. SARS-CoV, MERS-CoV and SARS-CoV-2) are associated with much greater morbidity and mortality. HCoVs have been relatively under-studied compared to other common respiratory infections, as historically they have presented with mild symptoms. This has led to a relatively limited understanding of their animal reservoirs, transmission and determinants of immune protection. To address this, human infection challenge studies with HCoVs have been performed that enable a detailed clinical and immunological analysis of the host response at specific time points under controlled conditions with standardised viral inocula. Until recently, all such human challenge studies were conducted with common cold HCoVs, with the study of SARS-CoV and MERS-CoV unacceptable due to their greater pathogenicity. However, with the emergence of SARS-CoV-2 and the COVID-19 pandemic during which severe outcomes in young healthy adults have been rare, human challenge studies with SARS-CoV-2 are now being developed. Two SARS-CoV-2 human challenge studies in the UK studying individuals with and without pre-existing immunity are underway. As well as providing a platform for testing of antivirals and vaccines, such studies will be critical for understanding the factors associated with susceptibility to SARS-CoV-2 infection and thus developing improved strategies to tackle the current as well as future HCoV pandemics. Here, we summarise the major questions about protection and pathogenesis in HCoV infection that human infection challenge studies have attempted to answer historically, as well as the knowledge gaps that aim to be addressed with contemporary models.

Preliminary study regarding the predicted body weight-based dexamethasone therapy in patients with COVID-19 pneumonia

BACKGROUND

The RECOVERY clinical trial reported that 6 mg of dexamethasone once daily for up to 10 days reduces the 28-day mortality in patients with coronavirus disease 2019 (COVID-19) receiving respiratory support. In our clinical setting, a fixed dose of dexamethasone has prompted the question of whether inflammatory modulation effects sufficiently reduce lung injury. Therefore, preliminary verification on the possibility of predicted body weight (PBW)-based dexamethasone therapy was conducted in patients with COVID-19 pneumonia.

METHODS

This single-center retrospective study was conducted in a Japanese University Hospital to compare the treatment strategies/management in different periods. Consecutive patients (n = 90) with COVID-19 pneumonia requiring oxygen therapy and were treated with dexamethasone between June 2020 and May 2021 were analyzed. Initially, 60 patients administered a fixed dexamethasone dose of 6.6 mg/day were defined as the conventional group, and then, 30 patients were changed to PBW-based therapy. The 30-day discharged alive rate and duration of oxygen therapy were analyzed using the Kaplan-Meier method and compared using the log-rank test. The multivariable Cox regression was used to evaluate the effects of PBW-based dexamethasone therapy on high-flow nasal cannula (HFNC), noninvasive ventilation (NIV), or mechanical ventilation (MV).

RESULTS

In the PBW-based group, 9, 13, and 8 patients were administered 6.6, 9.9, and 13.2 mg/day of dexamethasone, respectively. Additional respiratory support including HFNC, NIV, or MV was significantly less frequently used in the PBW-based group (P = 0.0046), with significantly greater cumulative incidence of being discharged alive and shorter oxygen demand within 30 days (92 vs. 89%, log-rank P = 0.0094, 90 vs. 92%, log-rank P = 0.0002, respectively). Patients treated with PBW-based therapy significantly decreased the use of additional respiratory support after adjusting for baseline imbalances (adjusted odds ratio, 0.224; 95% confidence interval, 0.062-0.813, P = 0.023). Infection occurred in 13 (21%) and 2 (7%) patients in the conventional and PBW-based groups, respectively (P = 0.082).

CONCLUSIONS

In patients with COVID-19 pneumonia requiring oxygen therapy, PBW-based dexamethasone therapy may potentially shorten the length of hospital stay and duration of oxygen therapy and risk of using HFNC, NPPV, or MV without increasing serious adverse events or 30-day mortality.

High-dose dexamethasone treatment for COVID-19 severe acute respiratory distress syndrome: a retrospective study

Low-dose dexamethasone reduces mortality in patients with coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS). We retrospectively analyzed the efficacy of high-dose dexamethasone in patients with COVID-19-related ARDS and evaluated factors affecting the composite outcome (death or invasive mechanical ventilation). From March 4th to April 1st 2020, 98 patients with COVID-19 pneumonia were included. Those who after at least 7 days from symptom onset presented a worsening of the respiratory function or of inflammatory biomarkers were started on intravenous high-dose dexamethasone (20 mg daily for 5 days, followed by 10 mg daily for 5 days). Most patients were males (62%) with a mean age of 69 years. Hypertension and cardiovascular disease (CVD) were prevalent. Following dexamethasone treatment, a significant improvement in PaO₂/FiO₂ (277.41 [178.5-374.8] mmHg vs. 146.75 [93.62-231.16] mmHg, p < 0.001), PaO₂ (88.15 [76.62-112.0] mmHg vs. 65.65 [57.07-81.22] mmHg, p < 0.001), and SpO₂ (96 [95-98]% vs. 94 [90-96]%, p < 0.001) was observed. A concomitant decrease in C-reactive protein and ferritin levels was found (132.25 [82.27-186.5] mg/L vs. 7.3 [3.3-24.2] mg/L and 1169 [665-2056] ng/mL vs. 874.0 [569.5-1434] ng/mL, respectively; p < 0.001 for both vs. baseline). CVD was found to increase the risk of the composite outcome (RR 7.64, 95% CI 1.24-47.06, p = 0.028). In hospitalized patients with COVID-19-related ARDS, high-dose dexamethasone rapidly improves the clinical status and decreases inflammatory biomarkers. CVD was found to increase the risk of the composite outcome. These data support the importance of randomized clinical trials with high-dose dexamethasone in COVID-19 patients.

Cytokine Storm Syndrome in SARS-CoV-2 Infections: A Functional Role of Mast Cells

Cytokine storm syndrome is a cascade of escalated immune responses disposing the immune system to exhaustion, which might ultimately result in organ failure and fatal respiratory distress. Infection with severe acute respiratory syndrome-coronavirus-2 can result in uncontrolled production of cytokines and eventually the development of cytokine storm syndrome. Mast cells may react to viruses in collaboration with other cells and lung autopsy findings from patients that died from the coronavirus disease that emerged in 2019 (COVID-19) showed accumulation of mast cells in the lungs that was thought to be the cause of pulmonary edema, inflammation, and thrombosis. In this review, we present evidence that a cytokine response by mast cells may initiate inappropriate antiviral immune responses and cause the development of cytokine storm syndrome. We also explore the potential of mast cell activators as adjuvants for COVID-19 vaccines and discuss the medications that target the functions of mast cells and could be of value in the treatment of COVID-19. Recognition of the cytokine storm is crucial for proper treatment of patients and preventing the release of mast cell mediators, as impeding the impacts imposed by these mediators could reduce the severity of COVID-19.

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

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