A comprehensive review and meta-analysis of the relationships between interleukin-7 levels and COVID-19 severity

Introduction: As the major mechanism for coronavirus disease 2019, cytokine storm-mediated organ harm continues to dominate current understanding. Despite the first hyper-inflammatory phase, emerging data show that virus-induced poor host immunity may be the true cause of mortality in many individuals. Interleukin 7 (IL-7) is an interleukin that participates in the COVID-19 cytokine storm and regulates the immune system. Its role in COVID-19 cytokine storms is thought to be related to its ability to stimulate the formation and activation of immune cells such as T cells and B cells. This meta-analysis aims to determine the relationship, if any, between interleukin-7 and COVID-19 severity. Methods: This study was planned as a systematic review and meta-analysis and followed the PRISMA guidelines. Four main electronic databases (Web of Science, PubMed, Scopus, and the Cochrane Central Register of Controlled Trials) were searched from January 1st, 2020 to September 2nd, 2022, to find papers investigating the prognostic significance of interleukin-7 in COVID-19-hospitalized adults. Google Scholar was used in addition to the online database search. A random effects model was used to calculate mean differences and 95% confidence interval (CIs) as well as the I2 statistics for heterogeneity analysis. Results: Seven papers were chosen for meta-analysis findings synthesis. All six trials reported interleukin-7 levels among severe and non-severe COVID-19 patients. Pooled analysis showed that IL-7 levels in the severe group were 62.79±81.03 pg/mL, compared to 33.39±56.54 pg/mL for the non-severe group (SMD =-0.17;95%CI:-0.93 to 0.60;p=0.67). Discussion: Available evidence suggests that elevated levels of IL-7 were not associated with the disease severity of COVID-19. While IL-7 levels alone may not have a substantial impact on COVID-19 severity, the interaction between IL-7 and other cytokines, immune cells, and variables such as viral load and genetics should be investigated further. Take-home message: This meta-analysis found that there was no strong link between levels of interleukin-7 and the severity of COVID-19. However, further research is needed to explore the interaction between IL-7 and other factors such as cytokines, immune cells, viral load, and genetics in order to better understand the role of IL-7 in COVID-19 pathogenesis. © 2023 by the authors.

Cytokine Profile in Different Post-Covid-19 Condition Phenotypes

Background: At least 10% of SARS-CoV-2 infected patients suffer from persistent symptoms for >12 weeks, known as post-COVID-19 condition (PCC) or Long Covid. Reported symptomatology is diverse with >200 physical and neurological debilitating symptoms. Here, we analyzed pro-inflammatory cytokine levels as a potential mechanism underlying persistent symptomatology. Method(s): Clinical data and samples used belong to the KING cohort extension, which includes clinically well characterized PCC (N=358, 59 persistent symptoms evaluated), COVID-19 recovered and uninfected subjects. We used Gower distances to calculate symptom's similarity between PCC and Ward's hierarchical clustering method to identify different symptom patterns among PCC patients. Cytokine levels of randomly selected PCC, recovered and uninfected subjects (N=193) were measured on plasma samples collected >6 months after acute infection using the 30-Plex Panel for Luminex. Mann- Whitney t-test was used to compare PCC vs recovered groups and Kruskal-Wallis t-test for >2 groups comparisons (PCC vs recovered vs Uninfected and within PCC clusters). FDR correction was applied for statistical significance (p-adj). Result(s): Hierarchical clustering identified 5 different PCC clusters according to their symptomatology, where PCC3 and PCC5 clusters showed higher prevalence of women ( >80%) and more persistent symptoms, while acute COVID-19 was mild in >80% of the patients. We selected 91 PCC (belonging to each cluster), 57 recovered and 45 uninfected subjects for cytokine profiling (Table 1). 13 soluble markers were significantly elevated (IL-1beta, Eotaxin, MIP-1beta, MCP-1, IL-15, IL-5, HGF, IFN-alpha, IL-1RA, IL-7, MIG, IL-4 and IL-8) in PCC and recovered groups compared to uninfected subjects (all p-adj< 0.04). In addition, PCC subjects tended towards higher levels of IL-1RA compared to recovered group (padj= 0.071). Within PCC clusters, FGF-basic and RANTES were elevated while IL-2 and MIG were decreased in PCC3 and PCC5 compared to the other PCC clusters (all p-adj< 0.04). TNF-alpha, IP-10, G-CSF and MIP-1alpha were decreased in PCC3 and PCC5 not reaching statistical significance (all p-adj=0.07). Conclusion(s): Some cytokines remained altered in all SARS-CoV-2 infected subjects independently of persistent symptoms after 6 months from acute infection. Differences between PCC and recovered individuals are limited after correction. Importantly, PCC cytokine profiles showed differences between clusters, which suggests different PCC subsyndromes with distinct etiology. Subjects Characteristics (Table Presented).

Potential Predictors for Disease Severity in Hospitalised COVID-19 Patients

Background and Objectives Several studies have shown that SARS-CoV-2 can induce a cytokine release storm which is a major cause of disease severity and death. Therefore, cytokine levels in the serum may predict disease severity and survival in patients with COVID-19. Methods We included 88 COVID-19 patients who were hospitalised at the Division of Pulmonology of the Vienna General Hospital between January and May 2021 in this observational trial. Blood samples for serum peptide measurements were drawn at the time closest to hospitalisation, at day 5, 9 and 13( +/- 1). We correlated the type of ventilation (nasal oxygen therapy, high flow nasal canula, non-invasive ventilation or mechanical ventilation), occurrence of consolidations on chest X-ray or if available HRCT and the level of care (general ward, IMCU or ICU) with serum peptide values. We assessed the concentration of cytokines (IL-1a, IL-1b, IL-1RA, IL-6, L-7, L-10, IFN- gamma and TNF-alpha), chemokines (CCL-3, CCL-4 and CCL-7) and growth factors (G-CSF, GM-CSF and VEGF). Results Patients were 68 years of age (median) and stayed in hospital between 5-171 days. The peak inspiratory pressure in patients receiving non-invasive ventilation or mechanical ventilation was significantly associated with IL-1RA, G-CSF and IFN-gamma and the fraction of inspired oxygen in patients receiving highflow nasal canula oxygen therapy was significantly associated with IL-6, IL-7, IFN-gamma, and CCL-7. Results are shown in Table 1. No investigated cytokine correlated with the type of ventilation, occurrence of consolidations on imaging and in-hospital mortality. Conclusions In conclusion, concentrations of IL-1RA, G-CSF, IL-6, IL-7, IFN-gamma, and CCL-7 were associated with more severe disease progression in hospitalised COVID-19 patients.

A Review on Therapeutic Potential of Indian Herbal Plants to Counter Viral Infection and Disease Pathogenesis

Herbal plant extracts or purified phytocomponents have been extensively used to treat several diseases since ancient times. The Indian Ayurvedic system and Chinese traditional medicines have documented the medicinal properties of important herbs. In Ayurveda, the polyherbal formulation is known to exhibit better therapeutic efficacy compared to a single herb. This review focuses on six key ayurvedic herbal plants namely, Tinospora cordifolia, Withania somnifera, Glycyrrhiza glabra/Licorice, Zingiber officinale, Emblica officinalis and Ocimum sanctum. These plants possess specific phytocomponents that aid them in fighting infections and keeping body healthy and stress-free. Plants were selected due to their reported antimicrobial and anti-inflammatory effects in several diseases and effectiveness in controlling viral pathogenesis. An ad-vanced literature search was carried out using Pubmed and google scholar. Result(s): These medicinal plants are known to exhibit several protective features against various diseases or infections. Here we have particularly emphasized on antioxidant, anti-inflammatory, anti-microbial and immunomodulatory properties which are common in these six plants. Recent literature analysis has revealed Ashwagandha to be protective for Covid-19 too. The formulation from such herbs can exhibit synergism and hence better effectiveness against infection and related dis-eases. The importance of these medicinal herbs becomes highly prominent as it maintains the har-monious balance by way of boosting the immunity in a human body. Further, greater mechanistic analyses are required to prove their efficacy in fighting infectious diseases like Covid-19. It opens the arena for in-depth research of identifying and isolating the active components from these herbs and evaluating their potency to inhibit viral infections as polyherbal formulations.Copyright © 2023 Bentham Science Publishers.

Persistence of inflammatory and vascular damage mediators 5 months after acute COVID-19

Background: In the acute phase, patients with severe COVID-19 exhibit pulmonary inflammation and vascular injury, as well as an exaggerated cytokine response. Aim(s): To describe the inflammatory cytokine and vascular injury mediator profiles in patients previously hospitalised with COVID-19, and to compare these profiles with those in healthy controls and in patients recovering from severe sepsis of other aetiology. Method(s): Plasma levels of 28 different cytokine, chemokine, angiogenic and vascular injury markers were measured by MSD V-PLEX multiplex assays in 49 post-COVID patients 5.0+/-1.9 (mean+/-SD) months after hospitalisation with COVID-19 pneumonia, 11 post-sepsis patients (5.4+/-2.9 months after hospitalised non-COVID sepsis) and 18 healthy controls. Kruskal-Wallis or ANOVA were used to compare groups;false discovery rate correction (Benjamini Hochberg) allowed for multiple testing. Result(s): In the post-COVID group, IL-6, TNFalpha, SAA, MCP1, Tie-2, Flt1, PIGF and CRP were significantly elevated, whereas IL-7 and bFGF were significantly depressed. The differences in TNFalpha, SAA, MCP1, Tie-2, Flt1, IL-7 and bFGF appeared unique to the post-COVID group, but increased IL-6, PIGF and CRP levels were also seen in postsepsis patients compared with controls. In post-COVID patients we found strong negative spearman correlations between each of IL-6 (r=-0.51) and CRP (r=-0.57) with TLCO %predicted (p<0.001) and positive correlations with post-recovery CT abnormality scores: IL-6 (r=0.28) and CRP (r=0.46), p<0.05. Conclusion(s): A unique signature of inflammatory and vascular damage markers is seen months after acute COVID19 infection. Further research is needed to determine their pathophysiological significance.

Understanding kidney injury in covid-19, a pressing priority

The 2019 novel coronavirus disease (COVID-19) is a newly defined infectious and highly contagious acute disease caused by the severe acute respiratory syndrome coronavirus 2 ( (SARS-CoV-2). COVID-19 is mainly characterized by an acute respiratory disease however it can also affect multiple other organ systems such as the kidney, gastrointestinal tract, heart, vascular system, and the central nervous system. Kidney involvement is frequent in patients with COVID-19 and this review aims to explore the available data on kidney and COVID-19. In conclusion, COVID-19 infection can affect renal function and may cause acute kidney injury (AKI), due to several mechanisms that need to be fully elucidated. As only supportive management strategies are available for treating AKI in COVID-19, it is necessary to identify and preserve renal function during SARS-CoV-2 infection.Copyright © 2021 The Author(s).

Herbal and Ayurvedic Plants as Remedial Approach for Viral Diseases with Focus on COVID-19: A Narrative Review

Background: Infectious diseases have posed a major threat to human survival for centu-ries and can devastate entire populations. Recently, the global outbreak of COVID-19 has increased exponentially, affecting more than 200 countries and millions of lives since the fall of 2019, largely due to the ineffectiveness of existing antiviral therapies. WHO announced it a public health emer-gency of international concern. A significant waiting period in antiviral therapy hindered by the rapid evolution of severe acute respiratory syndrome-coronavirus-2 aggravated the situation ensuing imposition of strict laws (e.g., communal dissociation, international travel restrictions, and mainte-nance of hygiene) that would help in inhibiting further outspread of COVID-19. Ayurveda system of medicine offers a holistic approach to the COVID-19 pandemic. Objective(s): This review aims to highlight the potential of medicinal herbs and Ayurvedic drugs as the remedial approach for viral diseases, such as COVID-19. Method(s): We reviewed the literature from journal publication websites and electronic databases, such as Bentham, Science Direct, Pub Med, Scopus, USFDA, etc. Result(s): The drugs used in the traditional system of medicine have the potential to prevent and cure the infected patient. Ayurvedic therapies are known for regulating immunity and rejuvenation properties that behold much promise in the management of COVID-19 disease. Government of India, Ministry of AYUSH recommends some precautionary fitness measures and an increase in immunity with special reference to respiratory health. Conclusion(s): While there is no medication for COVID-19 as of now, taking preventive measures and boosting body immunity is highly recommended. A number of medicinal plants that play an im-portant role in revitalizing the immune system are easily accessible in home remedies.Copyright © 2023 Bentham Science Publishers.

Use of mesenchymal stem cell therapy in COVID-19 related strokes.

Coronavirus disease 2019 (COVID-19) has affected a broad demographics, eliciting a more significant effect on specific groups such as males, African Americans, and Hispanic minorities. Treatment of COVID-19 often requires antiviral drugs or monoclonal antibodies. However, immunotherapies such as mesenchymal stem cells and mesenchymal stem cells-derived exosomal vesicles should be evaluated as treatment options for COVID-19. Mesenchymal stem cell therapy offers regenerative, anti-inflammatory, and immunomodulatory properties that can speed up the recovery from COVID-19. Mesenchymal stem cell therapy can also benefit COVID-19 patients who suffer from strokes, as COVID-19 increases the risk of strokes due to increased cytokines and clotting factors. Most stroke cases that occur in COVID-19 patients are ischemic strokes. Therefore, with the help of mesenchymal stem cell therapy and mesenchymal stem cells-derived exosomes, COVID-19-induced stroke patients might benefit from dual-ended treatment. The objective of this review was to discuss COVID-19 and stroke incidence and the available treatment options.

Predictive Value of Specific Cytokines for Lethal Covid-19 Outcome

In our study, we aimed to evaluate the significance of specific cytokines in blood plasma as predictive markers of COVID-associated mortality. Materials and methods. In plasma samples of 29 patients with PCR-confirmed COVID-19 we measured the concentrations of 47 molecules. These molecules included: interleukins and selected pro-inflammatory cytokines (IL-1alpha, IL-1beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-9, IL-12 (p40), IL-12 (p70), IL-13, IL-15, IL-17A/CTLA8, IL-17-E/IL-25, IL-17F, IL-18, IL-22, IL-27, IFNalpha2, IFNgamma, TNFalpha, TNFbeta/Lymphotoxin-alpha(LTA));chemokines (CCL2/MCP-1, CCL3/MIP-1alpha, CCL4/MIP-1beta, CCL7/MCP-3, CCL11/Eotaxin, CCL22/MDC, CXCL1/GROalpha, CXCL8/IL-8, CXCL9/MIG, CXCL10/IP-10, CX3CL1/Fractalkine);anti-inflammatory cytokines (IL-1Ra, IL-10);growth factors (EGF, FGF-2/FGF-basic, Flt-3 Ligand, G-CSF, M-CSF, GM-CSF, PDGF-AA, PDGFAB/BB, TGFalpha, VEGF-A);and sCD40L. We used multiplex analysis based on xMAP technology (Luminex, USA) using Luminex MagPix. As controls, we used plasma samples of 20 healthy individuals. Based on the results, we applied Receiver Operating Characteristic (ROC) analysis and Area Under Curve (AUC) values to compare two different predictive tests and to choose the optimal division point for disease outcome (survivors/non-survivors). To find optimal biomarker combinations, we as used cytokines concentrations as dependent variables to grow a regression tree using JMP 16 Software.Results. Out of 47 studied cytokines/chemokines/growth factors, we picked four pro-inflammatory cytokines as having high significance in evaluation of COVID-19 outcome: IL-6, IL-8, IL-15, and IL-18. Based on the results received, we assume that the highest significance in terms of predicting the outcome of acute COVID-19 belongs to IL-6 and IL-18. Conclusion. Analyzing concentrations of IL-6 and IL-18 before administering treatment may prove valuable in terms of outcome prognosis. Copyright © Arsentieva N.A. et al., 2022.

The Risk of COVID-19 in People Having a Particular Set of Gene

These risk factors of advancing age, male gender and co-existing health conditions like cancer, cardiovascular diseases, diabetes and obesity do not fully explain why some people have no or mild symptoms whereas others have severe symptoms. Genomewide association study (GWAS) identify a 3p21.31 gene cluster as a genetic susceptibility locus in patients with COVID-19 with respiratory failure. They also found a higher risk among persons with blood group A and protective effect for blood group O than among patients with other blood groups. The particular haplotype in a region of chromosome 3 is contributed to modern humans by neandertals. Another Neanderthal haplotype on chromosome 12 is associated with a 22% reduction in relative risk of becoming severely ill with COVID-19. The ApoE e4e4 homozygous genotype was found to increase the risk of severe COVID-19. Change in angiotensin converting enzyme (ACE) 2 gene was also found to be associated with increased risk of COVID-19, cardiovascular and pulmonary conditions. Copyright © 2021, Kathmandu University. All rights reserved.

Profound Dysregulation of T cell Homeostasis and Function in Patients With Severe COVID-19

PURPOSE OF THE STUDY: T cell lymphopenia is prevalent in severe coronavirus disease 2019 (COVID-19). This study evaluated associations with homeostatic and functional T cell responses in COVID-19 with the goal of identifying immunologic features of severe disease. STUDY POPULATION: Patients aged 18 years and older with symptomatic, real time-quantitative polymerase chain reaction confirmed SARS-CoV-2 (mild, n = 54;severe, n = 49) were recruited at 4 hospitals in the Canton of Zurich, Switzerland from April 2 to August 19, 2020, and a group of healthy controls recruited for comparison (n = 27). A subset (mild, n = 28;severe, n = 38, healthy, n = 22) had comprehensive T cell characterization. METHODS: In this prospective, observational, cross-sectional study, symptomatic participants with mild and severe COVID-19 and healthy controls were sampled at a single time point. Phenotypic and functional characteristics of T cells were evaluated using 40-parameter mass cytometry, flow cytometry, targeted proteomics, and functional assays. RESULTS: Compared with mild disease, severe COVID-19 was associated with T cell lymphopenia and redistribution of T cell populations, including loss of naïve and memory CD4+ and CD8+ T cells, skewing toward CD4+ T follicular helper cells and cytotoxic CD4+ T cells, and expansion of activated and exhausted T cells. Individuals with severe disease and T cell lymphopenia had signs of tissue migration, extensive T cell apoptosis, and impaired T cell responses to common viral antigens. Patients with severe disease also showed elevated interleukin-7 and increased T cell proliferation. Those sampled longest after symptom onset had higher T cell counts and improved antiviral T cell responses. CONCLUSIONS: Severe COVID-19 is characterized by extensive T cell dysfunction. Reduced naïve T cells and virus-specific memory T cell numbers are associated with severe disease and impaired T cell responses to viral antigens, particularly early in the disease. Increased T follicular helper cells may contribute to a robust antibody response often observed in COVID-19. T cell apoptosis is associated with lymphopenia and homeostatic T cell proliferation and T cell recovery in the later stages of disease.

Rapid increase of myeloid-derived suppressor cells and prolonged innate immune dysfunctions in patients with COVID-19

Background: PMN and monocytic myeloid-derived suppressor cells (PMN-MDSCs, M-MDSCs) are immunosuppressive cells rising during infections. Aim: To characterize the dynamic of MDSCs in relation with immune parameters in COVID-19 patients followed for 3 months. Methods: 56 SARS-CoV-2 infected adult patients hospitalized at CHUV were included. Blood was obtained at inclusion and 3 months later in 21 patients, and from 10 healthy controls. Blood was stimulated with TLR ligands. Leukocyte populations and cytokines were analyzed by flow cytometry, mass cytometry, multiplex bead assay and ELISA. Results: At hospital admission, PMN-MDSCs and M-MDSCs were increased 2-4-fold in COVID-19 patients (P <0.05). PMN-MDSCs and M-MDSCs counts were higher in severe than in moderate COVID-19 patients (P <0.005). PMN-MDSCs and M-MDSCs correlated positively with EGF and HGF (P <0.05). M-MDSCs correlated positively with IL-1β, IL-7, PDGF and VEGF (P <0.05). In whole blood stimulated with TLR ligands, the proportion of TNF and IL-6- producing monocytes and DCs were reduced in patients. After 32 months, MDSCs were back to normal levels, while the production of cytokines by blood, monocytes and DCs was still largely affected. Conclusions: PMN-MDSCs and M-MDSCs were elevated and correlated with disease severity in patients analyzed at hospitalization. Innate immune blood responses were impaired in patients, which persisted for up to 3 months. Our results suggest that COVID-19 induces rapid and long-standing innate immune dysregulation.

A novel virotherapy encoding human interleukin-7 improves ex vivo T lymphocyte functions in immunosuppressed patients with septic shock and critically ill COVID-19.

A majority of patients with sepsis surviving the first days in intensive care units (ICU) enter a state of immunosuppression contributing to their worsening. A novel virotherapy based on the non-propagative Modified Virus Ankara (MVA) expressing the human interleukin-7 (hIL-7) cytokine fused to an Fc fragment, MVA-hIL-7-Fc, was developed and shown to enhance innate and adaptive immunity and confer survival advantages in murine sepsis models. Here, we assessed the capacity of hIL-7-Fc produced by the MVA-hIL-7-Fc to improve ex vivo T lymphocyte functions from ICU patients with sepsis. Primary hepatocytes were transduced with the MVA-hIL-7-Fc or an empty MVA, and cell supernatants containing the secreted hIL-7-Fc were harvested for in vitro and ex vivo studies. Whole blood from ICU patients [septic shock = 15, coronavirus disease 2019 (COVID-19) = 30] and healthy donors (n = 36) was collected. STAT5 phosphorylation, cytokine production, and cell proliferation were assessed upon T cell receptor (TCR) stimulation in presence of MVA-hIL-7-Fc-infected cell supernatants. Cells infected by MVA-hIL-7-Fc produced a dimeric, glycosylated, and biologically active hIL-7-Fc. Cell supernatants containing the expressed hIL-7-Fc triggered the IL-7 pathway in T lymphocytes as evidenced by the increased STAT5 phosphorylation in CD3+ cells from patients and healthy donors. The secreted hIL-7-Fc improved Interferon-γ (IFN-γ) and/or Tumor necrosis factor-α (TNF-α) productions and CD4+ and CD8+ T lymphocyte proliferation after TCR stimulation in patients with bacterial and viral sepsis. This study demonstrates the capacity of the novel MVA-hIL-7-Fc-based virotherapy to restore ex vivo T cells immune functions in ICU patients with sepsis and COVID-19, further supporting its clinical development.

Correlation of COVID-19 Biomarkers with Disease Severity: A Retrospective Study

Introduction: Many viruses through aerosols, droplets, and droplet nuclei utilize the respiratory passages to establish not only localized respiratory tract infections but also systemic disease. The coronaviruses (CoV) are no exception. The two most common illnesses that occurred in the recent past were severe acute respiratory syndrome (SARS, 2003) and the Middle East respiratory syndrome (MERS, 2012).1 The current pandemic, which broke out in late December 2019, has been a major threat to global public health due to significant morbidity and mortality, akin to snapping of Thanos' fingers. The novel coronavirus was initially named the 2019-novel CoV (2019-nCoV), but because of nearly 80% genetic homology to SARS-CoV, the Coronavirus Study Group of International Committee rechristened this virus as SARS-CoV-2.1 The disease was named coronavirus disease 2019 (COVID-19) on January 12, 2020, by the World Health Organization (WHO).2 According to the Advisory Committee on dangerous pathogens UK, COVID-19 is assigned as a hazardous group-3 organism, meaning that it can cause severe human disease.3 The novel coronavirus was named the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2, 2019-nCoV) due to its high homology (∼80%) to SARS-CoV, which caused acute respiratory distress syndrome (ARDS) and high mortality during 2002-2003.4 The outbreak of SARS-CoV-2 was considered to have originally started via a zoonotic transmission associated with the seafood market in Wuhan, China. Later it was recognized that human-to-human transmission played a major role in the subsequent outbreak.5 The most common clinical manifestations of COVID-19 include fever, cough, dyspnea, fatigue, and myalgia. A few patients have developed severe pneumonia and they may present with acute respiratory distress syndrome (ARDS), extrapulmonary organ dysfunction, or even death. SARS-CoV-2 virus primarily affects the respiratory system, although other organ systems are also involved. Lower respiratory tract infection-related symptoms including fever, dry cough, and dyspnea were reported in the initial case series.6 In addition, headache, dizziness, generalized weakness, vomiting, and diarrhea were observed.7 It is now widely recognized that respiratory symptoms of COVID-19 are extremely heterogeneous, ranging from minimal symptoms to significant hypoxia with ARDS. The heterogeneous disease course of COVID-19 is unpredictable with most patients experiencing mild self-limiting symptoms. However, up to 30% require hospitalisation, and up to 17% of these require intensive care support for acute respiratory distress syndrome (ARDS), hyperinflammation, and multiorgan failure. 8-10 A cytokine storm in patients with severe disease was identified in the early reports of Wuhan patients and is intrinsic to disease pathology. In this cohort, elevated plasma interleukin (IL)-2, IL-7, IL-10, granulocyte colony-stimulating factor (GCSF), interferon γ-induced protein 10 (IP10, monocyte chemoattractant protein-1 (MCP1), macrophage inflammatory protein 1-alpha (MIP1A), and tumor necrosis factor-alpha (TNF-α) levels in ICU patients were identified. 6 Studies have shown that severe or fatal cases of COVID-19 disease are associated with an elevated white cell count, blood urea nitrogen, creatinine, markers of liver and kidney function, C-reactive protein (CRP), interleukin-6 (IL-6), lower lymphocyte (<1000/μL) and platelet counts (<100 × 109/L) as well as albumin levels compared with milder cases in which survival is the outcome. Subsequent studies have implicated IL-6 as a valuable predictor of adverse clinical outcome and a potential therapeutic target.11,12 One or more clinical and wet biomarkers may enable early identification of high-risk cases, assisting disease stratification and effective use of limited specialist resources. Age is a strong risk factor for severe illness, complications, and death.13,14 Patients with no underlying medical comorbid conditions have an overall case fatality rate of <1%. Case fatality is higher for patients with comorbidit es. The severe cases are associated with elevated levels of inflammatory biomarkers such as serum lactate dehydrogenase, creatine kinase, C-reactive protein (CRP), d-dimer, procalcitonin, and ferritin.15 Since laboratory medicine has always supported clinical decision-making in various infectious diseases, it is important to assess the ability of laboratory-derived biomarkers to facilitate risk stratification of COVID-19 disease. This study will comprehensively explore clinical disease features and routine laboratory tests associated with COVID-19 disease and its complications, to address their association with disease severity and outcome. Hence, the present retrospective study will be done at our tertiary care centre to assess the association between different laboratory biomarkers and disease severity and outcomes in COVID-19 patients. Aims and objectives: Clinical correlation of biomarkers and disease severity in COVID-19 patients-a retrospective study. Review of Literature: Xia et al.16 in 2020 defined disease stages and identified stages' determining factors are instructive for the definition of standards for home quarantine. The authors demonstrated pulmonary involvement on a chest CT scan in 97.9% of cases. It took 16.81 ± 8.54 (3-49) days from the appearance of the first symptom until 274 patients tested virus-negative in naso- and oropharyngeal (NP) swabs, blood, urine, and stool, and 234 (83%) patients were asymptomatic for 9.09 ± 7.82 (1-44) days. Subsequently, 131 patients were discharged. One hundred and sixty-nine remained in the hospital;these patients tested virus-free and were clinically asymptomatic because of widespread persisting or increasing pulmonary infiltrates. Hospitalization took 16.24 ± 7.57 (2-47) days;the time interval from the first symptom to discharge was 21.37 ± 7.85 (3-52) days. The authors concluded that with an asymptomatic phase, disease courses are unexpectedly long until the stage of virus negativity. NP swabs are not reliable in the later stages of COVID-19. Pneumonia outlasts virus-positive tests if sputum is not acquired. Imminent pulmonary fibrosis in high-risk groups demands follow-up examinations. Investigation of promising antiviral agents should heed the specific needs of mild and moderate COVID-19 patients. Keddie et al.17 in 2020 investigated the routine laboratory tests and cytokines implicated in COVID-19 for their potential application as biomarkers of disease severity, respiratory failure, and need for higher-level care. The authors found CRP, IL-6, IL-10, and LDH were most strongly correlated with the WHO ordinal scale of illness severity, the fraction of inspired oxygen delivery, radiological evidence of ARDS, and level of respiratory support. IL-6 levels of ≥3.27 pg/mL provide a sensitivity of 0.87 and specificity of 0.64 for a requirement of ventilation, and a CRP of ≥37 mg/L of 0.91 and 0.66. The authors concluded that reliable stratification of highrisk cases has significant implications on patient triage, resource management, and potentially the initiation of novel therapies in severe patients. Malik et al.18 in 2020 in a systematic review and meta-analysis assessed the role of biomarkers in evaluating the severity of disease and appropriate allocation of resources. Studies having biomarkers, including lymphocyte, platelets, d-dimer, lactate dehydrogenase (LDH), C-reactive protein (CRP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, procalcitonin (PCT), and creatine kinase (CK), and describing outcomes were selected with the consensus of three independent reviewers. The authors found lymphopenia, thrombocytopenia, elevated d-dimer, elevated CRP, elevated PCT, elevated CK, elevated AST, elevated ALT, elevated creatinine, and LDH were independently associated with a higher risk of poor outcomes. The authors concluded a significant association between lymphopenia, thrombocytopenia, and elevated levels of CRP, PCT, LDH, d-dimer, and COVID-19 severity. The results have the potential to be used as an early biomarker to impro e the management of COVID-19 patients, by identification of high-risk patients and appropriate allocation of healthcare resources in the pandemic. Tjendra et al.19 in 2020 assessed specific laboratory parameters and summarized the currently available literature on the predictive role of various biomarkers in COVID-19 patients.

COVID-19: DIARRHEA, INFLAMMATION AND INTESTINAL MICROBIOTA

Introduction: Increased inflammatory cytokines has been observed in COVID-19 patients and there is evidence showing an alteration in gut-microbiota composition. SARS-CoV-2 can cause gastrointestinal symptoms, such as diarrhea. Evidence of an altered gut-microbiota composition and cytokines levels in COVID-19 diarrhea patients is lacking. Objectives: To compare serum cytokine levels and gut microbiota between COVID-19 diarrhea (D-COVID- 19) and non-diarrhea (NonD-COVID-19) patients and non- COVID-19 controls (HC). Material and methods: We included 143 hospitalized COVID-19 patients (positive quantitative reverse transcription PCR) in a single University Hospital, and 53 ambulatory HC (negative rapid serological test) were included. Blood and stool samples were collected at hospital admission in COVID-19 patients and at the time of HC recruitment. 27- pro and anti-inflammatory cytokines (Bio-Plex Pro™, Bio- Rad) were measured. Gut microbiota composition and diversity profiles were characterized by sequencing the 16S rRNA gene V3-V4 region amplified using DNA extracted from stool samples. Bioinformatics analysis was performed with QIIME2 software. First, we compare cytokine levels between COVID- 19 and HC and then COVID-19 with and without diarrhea. All comparisons were adjusted for age, sex, and BMI with linear regression. Results: The mean age in COVID-19 patients was 54 +/- 15 years (F=50%) and 52 +/- 8 (F=62%) for HC. Diarrhea was present in 19 (13.29%) of COVID-19 patients. COVID-19 patients had significative higher levels of: IL- 1ra, IL-2, IL-6, IL-7, IL-8, IL-13, IP-10 and PDGF-bb. Significant lower values of: IL-9, FGF -basic, MIP-1β, TNF-α were observed in D-COVID-19 compared to NonD-COVID-19. COVID-19 patients had a significant reduction of bacterial species (p=0.0001), and diversity and complexity of the bacterial community (Shannon's index) (p=0.0001) compared to the HC. There was no difference between D-COVID-19 and NonD-COVID-19. There were also changes in the composition of the microbiota associated with COVID-19. At the phylum level, COVID-19 patients showed a significant decrease in Actinobacteria and Firmicutes, and an increase in Bacteroidetes. At species level, an increase of 4 species of the genus Bacteroides was observed in COVID-19 patients. 31 very diverse bacterial species were found, all decreased in D-COVID-19. Conclusions: An alteration in serum cytokine levels was observed between COVID-19 and HC. D-COVID-19 had a decrease in some proinflammatory cytokines. A significant decrease in richness and species diversity of gutmicrobiota was observed in COVID-19 patients compared to HC, but no significant differences were observed between D-COVID-19 and NonD-COVID-19. However, in D-COVID- 19, a decrease in some bacterial species was observed.(Table Presented)(Figure Presented)

GDF-15 IS A PREDICTOR OF MORTALITY IN CHRONIC KIDNEY DISEASE PATIENTS WITH COVID-19 INFECTION

BACKGROUND AND AIMS: A cytokine storm drives the pathogenesis of severe coronavirus disease (COVID-19) and several biomarkers with different mechanisms of action have been linked to mortality. Chronic kidney disease (CKD) emerged as a very common risk factor for severe COVID-19. Indeed, CKD patients are at increased risk of premature death from many causes, including, but not limited to, cardiovascular disease (CVD) and infections. In this study, we aimed to investigate the associations between the growth differentiation factor 15 (GDF-15), an established cardiovascular and inflammatory biomarker and outcomes in CKD patients hospitalized for COVID-19. METHOD: A retrospective study on COVID-19 hospitalized subjects in the acute phase of the disease. A broad range of cytokines (CD25, IL-18, TNF-α, TNF RI, TNF RII, GDF-15, IL-7, LIF, IL-6, CHITINASE3-LIKE1, RAGE and Pentraxin-3) were assessed in plasma (Luminex, ELISA) collected upon hospitalization. A total of 77 subjects were divided into two groups according to their estimated glomerular filtration rate (eGFR, by CKD-EPI formula), ≥45 mL/min (n = 44), or <45 mL/min (n = 33). RESULTS: We found no statistical differences between the two groups in terms of demographic features. Among comorbidities, we found a higher percentage of patients with diabetes in the eGFR < 45 group. Likewise, the serum tests upon admission showed in the eGFR < 45 group a higher value of neutrophilic count. Upon hospital admission, the patient groups were comparable in terms of symptoms, time from symptom onset to admission and death or discharge, radiological evidence of pneumonia and respiratory parameters and time of hospitalization. Furthermore, there were no statistical differences between medical therapy during hospitalization, need for respiratory support with Continuous Positive Airways Pressure or Non-Invasive Mechanical Ventilation, or death rather than discharge as the clinical outcome. Serum levels of 20 different compounds were measured in COVID-19 patients admitted to the hospital 4-5 days after the onset of symptoms. Interestingly, we found that patients with lower renal function (eGFR < 45 mL/min) had a significant increase of GDF-15, CD-25 and RAGE and, furthermore, higher serum levels of these molecules were detected in non-survivor patients and in those who needed ventilation. Also, TNFα, TNFR I, TNFR II, IL-7 and LIF had a significant increase in patients with eGFR < 45 mL/min with more elevated levels in non-survivor patients. In univariate analysis low and mid-low GDF-15 quartiles (<4.45 ng/mL) were associated with lower mortality risk, while mid-high and high quartiles (>4.45 ng/mL) were associated with higher mortality risk (Figure 1). Independent association between GDF-15 quartiles and mortality risk was confirmed in Cox model adjusted for eGFR, age, fever, dyspnoea and P/F [hazard ratio (HR) 2.28, 95% confidence interval (CI) 1.53-3.39, P < 0.0001) The strength of association between GDF-15 quartiles and mortality risk was increased in patients with eGFR < 45 mL/min/1.73 m2 (HR 2.53, CI 1.34-4.79) compared with the other eGFR group (HR 1.99, CI 1.17-3.39) (Table 1). CONCLUSION: Our results demonstrate that GDF-15 is an independent predictor of COVID-19 mortality in CKD patients. Given the reported increase of this cytokine with age and its possible mechanistic role in various pathological conditions, our findings suggest that GDF-15 signalling pathway inhibitors may be included as possible therapeutic candidates for COVID-19 in CKD. (Table Presented).

GDF-15 AS A PREDICTOR of MORTALITY in COVID-19: IMPLICATIONS for TREATMENT

Background: A cytokine storm drives the pathogenesis of severe COVID-19 and has therefore prompted the use of cytokine/transduction pathway inhibitors in the treatment of disease. However, numerous markers with different mechanisms of action have been linked to mortality, complicating the understanding of disease pathogenesis and the elaboration of therapeutic strategies. Methods: Retrospective study on COVID-19 hospitalized subjects in the acute phase of disease. A broad range of cytokines (CD25, IL-18, TNF-α, TNF RI, TNF RII, GDF-15, IL-7, LIF, IL-6, CHITINASE3-LIKE1, RAGE and Pentraxin-3) was assessed on plasma samples (Luminex, ELISA) collected upon hospitalization. Subjects were divided into two groups according to their clinical in-hospital death (Survivors: S;Non-Survivors: NS). Comparisons between groups were performed by Fisher's exact test or Mann-Whitney U test as appropriate. The association between each variable and mortality was analysed through univariate and multiple logistic regression models. Subsequently, survival analysis was conducted with Cox proportional hazard models. Results: 77 hospitalised Covid-19 patients were enrolled: 42 S and 35 NS (Figure 1A). As expected, in the NS group we found a higher proportion of subjects with fever and dyspnoea upon admission, development of ARDS and need of PEEP respiratory support (Figure 1A). NS also displayed significantly higher blood neutrophils/lymphocytes, C-reactive protein, LDH and procalcitonin as well as lower PaO2/FiO2 and peripheral O2 saturation values at admission (Figure 1A). In keeping with these findings, CD25, IL-18, IL-6, TNF-α, TNFRI, TNFRII, GDF-15, IL-7, LIF and Chitinase3-Like1, Pentraxin-3 and RAGE were significantly higher in NS than S (Figure 1B) and were associated to mortality in univariate regression models. In the multivariate regression model GDF-15 and fever were the two more relevant features associated with mortality (Figure 1C). In the survival analysis GDF-15 was the strongest predictor of mortality (HR 2,26, 1,55-3,31;p<0,01 reference group bottom quartile Figure 1D, E). Conclusion: Our in-depth characterization of the cytokine storm demonstrates that GDF-15 is an independent predictor of Covid-19 mortality. Given the reported increase of this cytokine with age and its possible mechanistic role in various pathological conditions, our findings suggest that GDF-15 signalling pathway inhibitors may be included as possible therapeutic candidates for Covid-19.

Genetic and structure of novel coronavirus COVID-19 and molecular mechanisms in the pathogenicity of coronaviruses

The recently identified 2019 novel coronaviruses (2019-nCoV) has caused extra-human infections. 2019-nCoV identified a global threat that is causing an outbreak of unusual viral pneumonia in patients with severe acute respiratory syndrome (SARS)-coronaviruses 2 (SARS-CoV-2). Considering the relatively high identity of the receptor-binding domain (RBD) in 2019-nCoV and SARS-CoV, it is urgent to assess the cross-reactivity of anti-SARS-CoV antibodies with 2019-nCoV spike protein, which could have important implications for rapid development of vaccines and therapeutic antibodies against 2019-nCoV. The zinc metallopeptidase angiotensin-converting enzyme 2 (ACE2) is the only known human homolog of the key regulator of blood pressure ACE. ACE2 also serves as the cellular entry point for the SARS virus, therefore, a prime target for pharmacological intervention. SARS-CoV-2 uses the SARS-CoV receptor for entry and the serine protease transmembrane protease serine 2 for spike (S) protein priming. That it is still necessary to develop novel mAbs that could bind specifically to 2019-nCoV RBD. Cell entry of coronaviruses depends on the binding of the viral S proteins to cellular receptors and S protein priming by host cell proteases. A transmembrane protease serine 2 inhibitor approved for clinical use blocked entry and might constitute a treatment option. Our results reveal important commonalities between SARS-CoV-2 and SARS-CoV infection and identify a potential target for antiviral intervention. This review will help understand the biology and potential risk of CoVs that exist in richness in wildlife such as bats. We provide a brief introduction to the pathogenesis of SARS-CoV and Middle East respiratory syndrome-CoV and interaction between the RBD of coronavirus spike protein and ACE2.

Recombinant human interleukin-7 reverses T cell exhaustion ex vivo in critically ill COVID-19 patients

BackgroundLymphopenia is a hallmark of severe coronavirus disease 19 (COVID-19). Similar alterations have been described in bacterial sepsis and therapeutic strategies targeting T cell function such as recombinant human interleukin 7 (rhIL-7) have been proposed in this clinical context. As COVID-19 is a viral sepsis, the objectives of this study were to characterize T lymphocyte response over time in severe COVID-19 patients and to assess the effect of ex vivo administration of rhIL-7.ResultsPeripheral blood mononuclear cells from COVID-19 patients hospitalized in intensive care unit (ICU) were collected at admission and after 20 days. Transcriptomic profile was evaluated through NanoString technology. Inhibitory immune checkpoints expressions were determined by flow cytometry. T lymphocyte proliferation and IFN-γ production were evaluated after ex vivo stimulation in the presence or not of rhIL-7. COVID-19 ICU patients were markedly lymphopenic at admission. Mononuclear cells presented with inhibited transcriptomic profile prevalently with impaired T cell activation pathways. CD4 + and CD8 + T cells presented with over-expression of co-inhibitory molecules PD-1, PD-L1, CTLA-4 and TIM-3. CD4 + and CD8 + T cell proliferation and IFN-γ production were markedly altered in samples collected at ICU admission. These alterations, characteristic of a T cell exhaustion state, were more pronounced at ICU admission and alleviated over time. Treatment with rhIL-7 ex vivo significantly improved both T cell proliferation and IFN-γ production in cells from COVID-19 patients.ConclusionsSevere COVID-19 patients present with features of profound T cell exhaustion upon ICU admission which can be reversed ex vivo by rhIL-7. These results reinforce our understanding of severe COVID-19 pathophysiology and opens novel therapeutic avenues to treat such critically ill patients based of immunomodulation approaches. Defining the appropriate timing for initiating such immune-adjuvant therapy in clinical setting and the pertinent markers for a careful selection of patients are now warranted to confirm the ex vivo results described so far.Trial registration ClinicalTrials.gov identifier: NCT04392401 Registered 18 May 2020, http:// clinicaltrials.gov/ct2/show/NCT04392401.