COVID-19 Cytokine Storm Research Articles

Dexamethasone-loaded chitosan-decorated PLGA nanoparticles: a step forward in attenuating the COVID-19 cytokine storm?

This study aims to develop and characterize poly (lactic-co-glycolic acid) (PLGA) nanoparticles decorated with chitosan (CS) for the encapsulation of dexamethasone (DEX) (NP-DEX-CS), targeting improved efficacy in the treatment of severe acute respiratory syndrome (SARS) associated with COVID-19. The nanoparticles were systematically characterized for size, zeta potential (ZP), morphology, encapsulation efficiency, and in vitro drug release. Incorporation of CS resulted in significant modifications in the nanoparticles' physical properties, notably an increase in size (from 207.3 ± 6.7nm to 264.4 ± 4.4nm) and a shift in ZP to positive values (from -11.8 ±1.4mV to +30.0 ± 1,6mV). The NP-DEX-CS formulation achieved a high encapsulation efficiency (~79%) and a drug loading capacity of 6.53 ± 0.02%.In addition, the in vitro release rate of DEX from NP-DEX-CS was lower compared to undecorated nanoparticles, with a reduction from approximately 64% to 37% within 24h. Microscopy analyses revealed a smoother surface on the CS-decorated nanoparticles. FTIR and XRD analyses confirmed successful chitosan coating and DEX encapsulation. The CS coating enhanced the tolerability of J774.A1 cells to the nanoparticles, particularly evident at the highest concentration (400ug/mL), resulting in a cell viability ≥70%. Importantly, the NP-DEX-CS significantly reduced levels of nitric oxide and inflammatory cytokines (IL-1, IL-6, IL-12, and TNF-α). These findings suggest that CS-decorated PLGA nanoparticles hold promise as an effective dexamethasone delivery system for treating SARS related to COVID-19.

Cytokine Storm in COVID-19: Exploring IL-6 Signaling and Cytokine-Microbiome Interactions as Emerging Therapeutic Approaches.

IL-6 remains a key molecule of the cytokine storms characterizing COVID-19, exerting both proinflammatory and anti-inflammatory effects. Emerging research underscores the significance of IL-6 trans-signaling over classical signaling pathways, which has shifted the focus of therapeutic strategies. Additionally, the synergistic action of TNF-α and IFN-γ has been found to induce inflammatory cell death through PANoptosis, further amplifying the severity of cytokine storms. Long COVID-19 patients, as well as those with cytokine storms triggered by other conditions, exhibit distinct laboratory profiles, indicating the need for targeted approaches to diagnosis and management. Growing evidence also highlights the gut microbiota's crucial role in modulating the immune response during COVID-19 by affecting cytokine production, adding further complexity to the disease's immunological landscape. Targeted intervention strategies should focus on specific cytokine cutoffs, though accurate cytokine quantification remains a clinical challenge. Current treatment strategies are increasingly focused on inhibiting IL-6 trans-signaling, which offers promise for more precise therapeutic approaches to manage hyperinflammatory responses in COVID-19. In light of recent discoveries, this review summarizes key research findings on cytokine storms, particularly their role in COVID-19 and other inflammatory conditions. It explores emerging therapeutic strategies targeting cytokines like IL-6, TNF-α, and IFN-γ, while also addressing open questions, such as the need for better biomarkers to detect and manage cytokine storms. Additionally, the review highlights ongoing challenges in developing targeted treatments that mitigate hyperinflammation without compromising immune function, emphasizing the importance of continued research in this field.

Cytokine Storm in Pathogenesis of COVID-19 Complications

The aim. To explore the current literature and key findings concerning the cytokine storm contribution to pathogenesis of COVID-19 complications and mortality, and summarize clinical and pathologic features of cytokine storm in COVID-19 patients. A cytokine storm is a hyperinflammatory state secondary to excessive production of cytokines by deregulated immune system. It manifests clinically as an influenza-like syndrome, which can be complicated by multi-organ failure and coagulopathy, leading in most severe cases even to death. Cytokine storm has recently emerged as key aspect in COVID-19 disease, as affected patients show high levels of several key pro-inflammatory cytokines, some of which also correlate with disease severity. The current review describes the role of critical cytokines in COVID-19-mediated cytokine storm. Key findings of the studies are provided further. A cytokine storm is associated with COVID-19 severity and is also a crucial cause of death from COVID-19. Impaired acquired immune responses and uncontrolled inflammatory innate responses may be associated with the mechanism of cytokine storm in COVID-19. Cytokine storm is defined as acute overproduction and uncontrolled release of pro-inflammatory markers, both locally and systemically. In COVID-19 patients, pyroptosis triggers the release of proinflammatory cytokines and affects macrophage and lymphocyte functions, causing peripheral lymphopenia. Cytokine storm is characterized by a clinical presentation of overwhelming systemic inflammation, hyperferritinemia, hemodynamic instability, and multi-organ failure. The cytokine storm clinical findings are attributed to the action of pro-inflammatory cytokines like interleukin-1, interleukin-6, tumor necrosis factor alpha, vascular endothelial growth factor.

Common for COVID-19 cytokine storm in patients with SARS-CoV-2 infection and CLL (chronic lymphocytic leukemia)

Common for COVID-19 cytokine storm in patients with SARS-CoV-2 infection and CLL (chronic lymphocytic leukemia)

COVID-19 Inflammatory Syndrome: Lessons from TNFRI and CRP about the Risk of Death in Severe Disease.

Background/Objectives: Cytokine storm in severe COVID-19 is responsible for irreversible tissue damage and death. Soluble mediators from the TNF superfamily, their correlation with clinical outcome, and the use of TNF receptors as a potent predictor for clinical outcome were evaluated. Methods: Severe COVID-19 patients had the levels of soluble mediators from the TNF superfamily quantified and categorized according to the clinical outcome (death versus survival). Statistical modeling was performed to predict clinical outcomes. Results: COVID-19 patients have elevated serum levels from the TNF superfamily. Regardless of sex and age, the sTNFRI levels were observed to be significantly higher in deceased patients from the first weeks following the onset of symptoms. We analyzed hematological parameters and inflammatory markers, and there was a difference between the groups for the following factors: erythrocytes, hemoglobin, hematocrit, leukocytes, neutrophils, band cells, lymphocytes, monocytes, CRP, IL-8, IFN-γ, IL-10, IL-6, IL-4, IL-2, leptin MIF sCD40L, and sTNFRI (p < 0.05). A post hoc analysis showed an inferential capacity over 70% for some hematological markers, CRP, and inflammatory mediators in deceased patients. sTNFRI was strongly associated with death, and the sTNFRI/sTNFRII ratio differed between outcomes (p < 0.001; power above 90%), highlighting the impact of these proteins on clinical results. The final logistic model, including sTNFRI/sTNFRII and CRP, indicated high sensitivity, specificity, accuracy, and an eight-fold higher odds ratio for an unfavorable outcome. Conclusions: The joint use of the sTNFRI/sTNFRII ratio with CRP proves to be a promising tool to assist in the clinical management of patients hospitalized for COVID-19.

Cytokine Profile in Patients with Postacute Sequelae of COVID-19.

The enduring impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its disease manifestation, COVID-19, on public health remains significant. Postacute sequelae of SARS-CoV-2 infection (PASC) affect a considerable number of patients, impairing their quality of life. While the role of the cytokine storm in acute COVID-19 is well established, its contribution to the pathophysiology of PASC is not fully understood. This study aimed to analyze the cytokine profile of patients with PASC following in vitro stimulation of Toll-like receptor (TLR) pathways, comparing them with a healthy control group. From October 2020 till March 2021, Brugmann University Hospital's clinical research unit included patients with PASC in the study. Whole blood samples were collected from 50 patients and 25 healthy volunteers. After in vitro stimulation under five different conditions, cytokine levels were measured using a multiplex method. Significantly decreased cytokine levels were observed in patients with PASC compared with healthy volunteers, particularly after TLR4 (interleukin [IL]-1α, IL-1β, IL-2, IL-10, interferon (IFN)α, IFNγ, IFNω, and tumor necrosis factor (TNF)α) and TLR7/8 (IL-1α, IL-1β, IFNα, IFNω, IFNγ, and TNFα) pathway stimulation. Principal component analysis identified two distinct clusters, suggesting a likely dysregulation of immunity involving TLR4 and TLR7/8 pathways in patients with PASC. Our study suggests that TLR4 and TLR7/8 pathways play a role in the pathophysiology of PASC. Continuous basal activation of immunity could explain the high basal concentrations of cytokines described in these patients and the decreased amplitude of response of these signaling pathways following specific stimulation.

Idiopathic multicentric Castleman disease-TAFRO after COVID-19: A case report.

TAFRO syndrome, a rare disease characterised by thrombocytopaenia, anasarca, fever, reticulin fibrosis, and organomegaly, is thought to be caused by hypercytokinaemia. It is a heterogeneous clinical entity, and a recent comprehensive international definition defined TAFRO syndrome with lymph node histopathology consistent with idiopathic multicentric Castleman disease (iMCD) as iMCD-TAFRO. Herein, we present a rare case of iMCD-TAFRO following coronavirus disease 2019 (COVID-19) infection. A 62-year-old Japanese woman, initially diagnosed with COVID-19, developed a persistent fever and fluid retention, prompting the diagnosis of iMCD-TAFRO. Following the initiation of prednisolone and cyclosporine, her symptoms gradually resolved. Therefore, we discuss the potential pathophysiological link between COVID-19 and iMCD-TAFRO, emphasising the role of cytokine storms. This case report highlights the importance of recognising the spectrum of inflammatory states after COVID-19 and differentiating iMCD-TAFRO after COVID-19 from the COVID-19 cytokine storm syndrome.

MRNA vaccination reduces the thrombotic possibility in COVID-19: Inflammation risk estimates

Thrombosis is a common clinical feature associated with morbidity and mortality in coronavirus disease-2019 (COVID-19) patients. Cytokine storm in COVID-19 increases patients' systemic inflammation, which can cause multiple health consequences. In this work, we aimed to indicate the effect of Pfizer-BioNTech vaccination on the modulation of monocyte chemoattractant protein-3 (MCP-3), matrix metalloproteinase 1 (MMP-1), and tumor necrosis factor-alpha (TNF-α) levels, and other systemic inflammatory biomarkers that associates with COVID-19 severity in patients who suffers from thrombosis consequences. For this purpose, ninety people were collected from Ibn Al-Nafees Hospital and divided into three groups each of which contained 30 people, 15 of them were venous thromboembolism (VTE) positive and the other were VTE negative. The three groups were non-vaccinated COVID-19, vaccinated COVID-19, and control. The levels of MCP-3 and TNF-α were significantly (p < 0.05) increased in vaccinated and non-vaccinated COVID-19 patients regardless of their thrombosis condition, while MMP-1 level was non-significantly (p > 0.05) higher in vaccinated patients compared to control. MCP-3 and TNF-α were correlated positively with D-dimer (r = 0.544 and r = 0.513, respectively) in non-vaccinated patients, while MMP-1 and TNF-α were correlated positively with D-dimer (r = 0.624 and r = 0.575, respectively) in vaccinated patients. The odds ratio of MCP-3 (2.252), MMP-1 (1.062), and TNF-α (1.360) were reduced in vaccinated patients (2.093, 1.022, and 1.301 for MCP-3, MMP-1, and TNF-α respectively). Thus, MCP-3 plays a vital role in COVID-19 pathophysiology, and vaccination can reduce the risk of developing VTE in COVID-19 patients, and improve the inflammatory condition of patients.

S100A9: The Unusual Suspect Connecting Viral Infection and Inflammation.

The study of S100A9 in viral infections has seen increased interest since the COVID-19 pandemic. S100A8/A9 levels were found to be correlated with the severity of COVID-19 disease, cytokine storm, and changes in myeloid cell subsets. These data led to the hypothesis that S100A8/A9 proteins might play an active role in COVID-19 pathogenesis. This review explores the structures and functions of S100A8/9 and the current knowledge on the involvement of S100A8/A9 and its constituents in viral infections. The potential roles of S100A9 in SARS-CoV-2 infections are also discussed.

Rosuvastatin Administration and Its Effect on the IL-6, IL-1β, and TNF-α Cytokines Levels in Peripheral Blood Mononuclear Cells of Type II Diabetes Mellitus Patients with COVID-19

Objective: Patients with cardiovascular disease (CVDs) have been reported to have the potential to experience severe COVID-19. The inflammatory cytokines such as IL-6, IL-1β, and TNF-α are frequently found in the COVID-19 cytokine storm. Because of the pleiotropic effect Rosuvastatin could be useful as an anti-inflammatory drug to suppress cytokine storms for possible COVID-19 therapy. This study aims to study the effect of rosuvastatin administration on IL-6, IL-1β, and TNF-α on peripheral blood mononuclear cells in type 2 diabetes mellitus patients stimulated with the SARS-CoV-2 spike protein. Material and methods: Mononuclear cells were isolated from peripheral venous blood, and then stimulated with the SARS-CoV-2 subunit S1 spike protein and incubated for 24 hours. Cells that had been stimulated by the SARS-CoV-2 spike protein were separated into two groups. Group 1 was the control group, which was not given rosuvastatin. Group 2 was given rosuvastatin at a dose of 20 μM. The expressions of IL-6, IL-1β, and TNF-α were measured from the cell supernatant using the ELISA method. Results: Spike protein stimulation significantly increased the expression of IL-6, IL-1β, and TNF-α (p= 0.37). Rosuvastatin administered at a dose of 20 μM did not significantly decrease IL-6 (p = 0.568) or IL-1β (p = 0.848) expression but increased TNF-α expression (p = 0.792). Conclusion: Rosuvastatin administration did not affect the expression of IL-6, IL-1β, and TNF-α in peripheral blood mononuclear cells of diabetics with stimulation of the SARS-CoV-2 spike protein.

Potential marker subset of blood-circulating cytokines on hematopoietic progenitor-to-Th1 pathway in COVID-19.

In this study, we analyzed a relatively large subset of proteins, including 109 kinds of blood-circulating cytokines, and precisely described a cytokine storm in the expression level and the range of fluctuations during hospitalization for COVID-19. Of the proteins analyzed in COVID-19, approximately 70% were detected with Bonferroni-corrected significant differences in comparison with disease severity, clinical outcome, long-term hospitalization, and disease progression and recovery. Specifically, IP-10, sTNF-R1, sTNF-R2, sCD30, sCD163, HGF, SCYB16, IL-16, MIG, SDF-1, and fractalkine were found to be major components of the COVID-19 cytokine storm. Moreover, the 11 cytokines (i.e., SDF-1, SCYB16, sCD30, IL-11, IL-18, IL-8, IFN-γ, TNF-α, sTNF-R2, M-CSF, and I-309) were associated with the infection, mortality, disease progression and recovery, and long-term hospitalization. Increased expression of these cytokines could be explained in sequential pathways from hematopoietic progenitor cell differentiation to Th1-derived hyperinflammation in COVID-19, which might also develop a novel strategy for COVID-19 therapy with recombinant interleukins and anti-chemokine drugs.

Inflammatory Polymorphisms (IL-6 rs1800796, IL-10 rs1800896, TNF-α rs1800629, and IFITM3 rs12252) Are Not Associated with Post-COVID Symptoms in Previously Hospitalized COVID-19 Survivors.

The aim of this study was to identify the association between four selected inflammatory polymorphisms with the development of long-term post-COVID symptoms in subjects who had been hospitalized due to SARS-CoV-2 infection during the first wave of the pandemic. These polymorphisms were selected as they are associated with severe COVID-19 disease and cytokine storm, so they could be important to prognoses post-COVID. A total of 408 (48.5% female, age: 58.5 ± 14.0 years) previously hospitalized COVID-19 survivors participated. The three potential genotypes of the following four single-nucleotide polymorphisms, IL-6 rs1800796, IL-10 rs1800896, TNF-α rs1800629, and IFITM3 rs12252, were obtained from non-stimulated saliva samples of the participants. The participants were asked to self-report the presence of any post-COVID symptoms (defined as symptoms that had started no later than one month after SARS-CoV-2 acute infection) and whether the symptoms persisted at the time of the study. At the time of the study (mean: 15.6, SD: 5.6 months after discharge), 89.4% of patients reported at least one post-COVID symptom (mean number of symptoms: 3.0; SD: 1.7). Fatigue (69.3%), pain (40.9%), and memory loss (27.2%) were the most prevalent post-COVID symptoms in the total sample. Overall, no differences in the post-COVID symptoms depending on the IL-6 rs1800796, IL-10 rs1800896, TNF-α rs1800629, and IFITM3 rs12252 genotypes were seen. The four SNPs assessed, albeit having been previously associated with inflammation and COVID-19 severity, did not cause a predisposition to the development of post-COVID symptoms in the previously hospitalized COVID-19 survivors.

Effects of Upper Arm and Breathing Exercise on Interleukin-6 in COVID-19 Patients

Introduction: COVID-19 disease has become a comprehensive world issue and has been declared a significant threat to global health. Interleukin-6 (IL-6) is an important inflammatory marker and one of the triggers of the cytokine storm in COVID-19, where increased levels can be an independent predictor of COVID-19 mortality. This study aimed to observe the effect of upper arm and breathing exercises on IL-6 levels in severe COVID-19 patients. Methods: The study design was quasi-experimental, with blood tests conducted before and after the examination. A total of 20 patients with confirmed COVID-19 were involved, divided into intervention and control groups. Results: Blood tests to determine baseline IL-6 levels were performed in all patients. Patients from the intervention group were given upper arm and breathing exercises for ten days, twice a day, via video tutorials on mobile phones, while patients from the control group did not receive any exercises. Patients from the intervention group obtained mean pre- and post-exercise IL-6 levels of 42.38 ± 48.48 and 16.78 ± 18.29, respectively (p = 0.005). Conclusion: Upper arm and breathing exercises showed significant changes in IL-6 levels in severe COVID-19 patients.

The Impact of Pathogens on Sepsis Prevalence and Outcome.

Sepsis, a severe global healthcare challenge, is characterized by significant morbidity and mortality. The 2016 redefinition by the Third International Consensus Definitions Task Force emphasizes its complexity as a "life-threatening organ dysfunction caused by a dysregulated host response to infection". Bacterial pathogens, historically dominant, exhibit geographic variations, influencing healthcare strategies. The intricate dynamics of bacterial immunity involve recognizing pathogen-associated molecular patterns, triggering innate immune responses and inflammatory cascades. Dysregulation leads to immunothrombosis, disseminated intravascular coagulation, and mitochondrial dysfunction, contributing to the septic state. Viral sepsis, historically less prevalent, saw a paradigm shift during the COVID-19 pandemic, underscoring the need to understand the immunological response. Retinoic acid-inducible gene I-like receptors and Toll-like receptors play pivotal roles, and the cytokine storm in COVID-19 differs from bacterial sepsis. Latent viruses like human cytomegalovirus impact sepsis by reactivating during the immunosuppressive phases. Challenges in sepsis management include rapid pathogen identification, antibiotic resistance monitoring, and balancing therapy beyond antibiotics. This review highlights the evolving sepsis landscape, emphasizing the need for pathogen-specific therapeutic developments in a dynamic and heterogeneous clinical setting.

The therapeutic potential of gelsolin in attenuating cytokine storm, ARDS, and ALI in severe COVID-19.

Severe COVID-19 cases often progress to life-threatening conditions such as acute respiratory distress syndrome (ARDS), sepsis, and multiple organ dysfunction syndrome (MODS). Gelsolin (GSN), an actin-binding protein with anti-inflammatory and immunomodulatory properties, is a promising therapeutic target for severe COVID-19. Plasma GSN levels are significantly decreased in critical illnesses, including COVID-19, correlating with dysregulated immune responses and poor outcomes. GSN supplementation may mitigate acute lung injury, ARDS, and sepsis, which share pathophysiological features with severe COVID-19, by scavenging actin, modulating cytokine production, enhancing macrophage phagocytosis, and stabilizing the alveolar-capillary barrier. Preliminary data indicate that recombinant human plasma GSN improves oxygenation and lung function in severe COVID-19 patients with ARDS. Although further research is needed to optimize GSN therapy, current evidence supports its potential to mitigate severe consequences of COVID-19 and improve patient outcomes. This review provides a comprehensive analysis of the biological characteristics, mechanisms, and therapeutic value of GSN in severe COVID-19.

COVID-19 Pneumonia and Cytokine Storm Syndrome.

Virus-associated cytokine storm syndrome (CSS) has been recognized for a long time and the classic viruses associated are the herpes viruses EBV, CMV, and HHV-8 as described in chapters IVa,b. In addition, pandemic viruses such as influenza, SARS, and MERS can result in severe CSS that might ultimately lead to severe acute respiratory distress syndrome (ARDS) and death [1-3]. A new pandemic caused by SARS-CoV-2 that started in 2019 has defined another chapter in the virus-associated CSS. The clinical spectrum of SARS-CoV-2 infection has many faces. In most people, it will be asymptomatic, but it can also result in severe COVID-19 pneumonia, ARDS, and multiorgan failure depending on age, comorbidities, and immune status [4]. In addition, this pandemic has known many different stages and developed in a unique way in the first 2years. It started in a setting where there was no immunity to the virus and after a year, highly effective vaccines were introduced and herd immunity built up over time. However, vaccine effectiveness was waning over time depending on multiple factors, and novel variant strains of the virus circulated across different areas in the world. Antiviral therapy was developed and introduced, and treatment changed from giving no immunomodulatory treatment, followed by the introduction of corticosteroids [5], and later the addition of more targeted strategies such as JAK inhibitors [6] and blocking IL-6 signaling [7]. Therefore, the scientific literature published on COVID-19 must be seen in the context of a highly dynamic and rapidly changing pandemic, making it difficult to compare results from early studies to more recent reports even within 2years. Still, a lot has been learned over a very short period. It has become apparent that severe COVID-19 is predominantly a disease of immune dysregulation with components that can be defined as CSS. It has unique features and overlapping characteristics with other CSSs, and immunological treatment addressing the CSS has been extensively explored, which will be described here.

Potential of traditional medicines in alleviating COVID-19 symptoms.

This review discusses the prevention and treatment of coronavirus disease 2019 (COVID-19) caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Mutations in its spike glycoprotein have driven the emergence of variants with high transmissibility and immune escape capabilities. Some antiviral drugs are ineffective against the BA.2 subvariant at the authorized dose. Recently, 150 natural metabolites have been identified as potential candidates for development of new anti-COVID-19 drugs with higher efficacy and lower toxicity than those of existing therapeutic agents. Botanical drug-derived bioactive molecules have shown promise in dampening the COVID-19 cytokine storm and thus preventing pulmonary fibrosis, as they exert a strong binding affinity for viral proteins and inhibit their activity. The Health Ministry of Thailand has approved Andrographis paniculata (Jap. Senshinren) extracts to treat COVID-19. In China, over 85% of patients infected with SARS-CoV-2 receive treatments based on traditional Chinese medicine. A comprehensive map of the stages and pathogenetic mechanisms related to the disease and effective natural products to treat and prevent COVID-19 are presented. Approximately 10% of patients with COVID-19 are affected by long COVID, and COVID-19 infection impairs mitochondrial DNA. As the number of agents to treat COVID-19 is limited, adjuvant botanical drug treatments including vitamin C and E supplementation may reduce COVID-19 symptoms and inhibit progression to long COVID.

Using an Antagonist of Chimeric Receptor Antigen T Cell Therapy to Prevent Cytokine Storm in COVID-19: A Hypothesis

SARS-COV-2 pandemic is almost 3-years-old and remains a case for concern. An overwhelming production of pro-inflammatory cytokines in the context of COVID-19, not only impairs viral clearance but also promotes paradoxically hyperinflammation including cytokine storm; an unfortunate event leading to organ failure following long term damage due to inflammation and even death.

The possible role of nuclear factor erythroid-2-related factor 2 activators in the management of Covid-19.

COVID-19 is caused by a novel SARS-CoV-2 leading to pulmonary and extra-pulmonary manifestations due to oxidative stress (OS) development and hyperinflammation. COVID-19 is primarily asymptomatic though it may cause acute lung injury (ALI), acute respiratory distress syndrome (ARDS), systemic inflammation, and thrombotic events in severe cases. SARS-CoV-2-induced OS triggers the activation of different signaling pathways, which counterbalances this complication. One of these pathways is nuclear factor erythroid 2-related factor 2 (Nrf2), which induces a series of cellular interactions to mitigate SARS-CoV-2-mediated viral toxicity and OS-induced cellular injury. Nrf2 pathway inhibits the expression of pro-inflammatory cytokines and the development of cytokine storm in COVID-19. Therefore, Nrf2 activators may play an essential role in reducing SARS-CoV-2 infection-induced inflammation by suppressing NLRP3 inflammasome in COVID-19. Furthermore, Nrf2 activators can attenuate endothelial dysfunction (ED), renin-angiotensin system (RAS) dysregulation, immune thrombosis, and coagulopathy. Thus this mini-review tries to clarify the possible role of the Nrf2 activators in the management of COVID-19. Nrf2 activators could be an effective therapeutic strategy in the management of Covid-19. Preclinical and clinical studies are recommended in this regard.

Inflammatory Markers in Hemophagocytic Lymphohistiocytosis - a Single Centre Study

BACKGROUND Hemophagocytic lymphohistiocytosis (HLH) has significant clinical and biochemical overlap with other cytokine storm syndromes including Adult-Onset Still's disease (AOSD) and COVID-19 cytokine storm (CCS). Diagnosis of HLH is based largely on the HLH-2004 criteria which carry certain limitations. Many of the tests included in these criteria such as flow cytometry for NK cell cytotoxicity and soluble CD25 levels are only available in specialized centres. Moreover, they can take days to weeks to result, leading to delays in diagnosis. Biomarkers that are unique to HLH and more readily available are needed to ensure a timelier diagnosis of this life-threatening disease. C-reactive protein (CRP) is a sensitive marker of inflammation that is driven by IL-6 activity, a cytokine that is significantly elevated in AOSD and CCS but comparatively less so in HLH. Our study sought to determine whether lower levels of CRP, in conjunction with other patterns of inflammatory markers, could reliably distinguish HLH from AOSD and CCS. METHODS This was a single-centre, retrospective study examining adult ( n=45) and pediatric ( n=12) patients with HLH, and adult patients with AOSD ( n=11) and CCS ( n=13). Patients were enrolled from Vancouver General Hospital between January 1 st, 2000, to June 28 th, 2023. CRP and ferritin levels were collected for each patient if available, and values were included in analysis only if drawn prior to HLH-specific treatment. Ferritin levels were included to add to our understanding of different patterns of inflammation seen in similar cytokine storm syndromes. The Kruskal-Wallis test was used to compare CRP and ferritin values in total HLH cases compared to AOSD and CCS. Diagnostic performance of CRP was analyzed by performing a receiver operating characteristic (ROC) curve for CRP in HLH patients using the Youden index to identify the optimal cut-off point for CRP values. RESULTS In total, eighty-one patients were included in the study. Median CRP was significantly lower in HLH compared to AOSD (68.9 mg/L versus 168.0 mg/L, p &amp;lt; 0.001) and CCS (68.9 mg/L versus 121.0 mg/L, p = 0.024) (Figure 1). Median serum ferritin levels were significantly lower in CCS compared to HLH (1,386 ng/mL versus 16,722, p &amp;lt; 0.001) and AOSD (1,3860 ng/mL versus 12,480 ng/mL, p = 0.016). There was no significant difference in ferritin levels between HLH and AOSD. The ROC curve was performed for CRP values in total HLH cases which demonstrated an Area Under the Curve (AUC) of 0.799, indicating a fair diagnostic performance in differentiating HLH, with a sensitivity of 66.1% and specificity of 87.5% for CRP values less than 94.5 mg/L, as calculated by Youden's index. CONCLUSION CRP is significantly lower in HLH compared to AOSD and CCS, suggesting that mild to moderate elevations in CRP reflect the comparatively lower IL-6 activity underlying HLH. When used in conjunction with other inflammatory markers, especially marked hyperferritinemia, a comparatively lower CRP value helps capture the unique cytokine pattern underlying HLH, and is a useful, easily accessible biomarker than can aid in the diagnosis of HLH.