Specific cytokines in the inflammatory cytokine storm of patients with COVID-19-associated acute respiratory distress syndrome and extrapulmonary multiple-organ dysfunction

The Interplay of HIV and Long COVID in Sub-Saharan Africa: Mechanisms of Endothelial Dysfunction

PURPOSE OF REVIEW

Long COVID affects approximately 5 million people in Africa. This disease is characterized by persistent symptoms or new onset of symptoms after an acute SARS-CoV-2 infection. Specifically, the most common symptoms include a range of cardiovascular problems such as chest pain, orthostatic intolerance, tachycardia, syncope, and uncontrolled hypertension. Importantly, these conditions appear to have endothelial dysfunction as the common denominator, which is often due to impaired nitric oxide (NO) mechanisms. This review discusses the role of mechanisms contributing to endothelial dysfunction in Long COVID, particularly in people living with HIV.

RECENT FINDINGS

Recent studies have reported that increased inflammation and oxidative stress, frequently observed in Long COVID, may contribute to NO dysfunction, ultimately leading to decreased vascular reactivity. These mechanisms have also been reported in people living with HIV. In regions like Africa, where HIV infection is still a major public health challenge with a prevalence of approximately 26 million people in 2022. Specifically, endothelial dysfunction has been reported as a major mechanism that appears to contribute to cardiovascular diseases and the intersection with Long COVID mechanisms is of particular concern. Further, it is well established that this population is more likely to develop Long COVID following infection with SARS-CoV-2. Therefore, concomitant infection with SARS-CoV-2 may lead to accelerated cardiovascular disease. We outline the details of the worsening health problems caused by Long COVID, which exacerbate pre-existing conditions such as endothelial dysfunction. The overlapping mechanisms of HIV and SARS-CoV-2, particularly the prolonged inflammatory response and chronic hypoxia, may increase susceptibility to Long COVID. Addressing these overlapping health issues is critical as it provides clinical entry points for interventions that could improve and enhance outcomes and quality of life for those affected by both HIV and Long COVID in the region.

Calcifediol or Corticosteroids in the Treatment of COVID-19: An Observational Study

Medical treatment of coronavirus 19 disease (COVID-19) is a therapeutic challenge. The available data strongly suggest that calcifediol treatment may reduce the severity of COVID-19, and corticosteroids are the treatment of choice worldwide for severe COVID-19. Both have a very similar action profile, and their combined use in patients may modify the contribution of each administered compound.

OBJECTIVE

To evaluate how treatment with calcifediol and/or corticosteroids in medical practice modified the need for ICU admission, death, or poor prognosis of patients hospitalized with COVID-19 during the first outbreaks.

DESIGN, PATIENTS AND SETTING

A retrospective observational cohort study of patients admitted for COVID-19 to the Pneumology Unit of the Hospital Universitario Reina Sofía (Córdoba, Spain).

INTERVENTIONS

Patients were treated with calcifediol or/and corticosteroids with the best available therapy and standard care, according to clinical practice guidelines.

MEASUREMENTS

Admission to the intensive care unit (ICU) or death during hospitalization and poor prognosis.

RESULTS

Seven hundred and twenty-eight patients were included. According to the treatment received, they were included in four groups: calcifediol (n = 68), glucocorticoids (n = 112), both (n = 510), or neither (n = 38). Of the 578 patients treated with calcifediol, 88 were admitted to the ICU (15%), while of the 150 not treated with calcifediol, 39 required ICU admission (26%) (p < 0.01). Among the patients taking calcifediol without glucocorticoids, only 4 of 68 (5.8%) required ICU admission, compared to 84 of 510 (16.5%) treated with both (p = 0.022). Of the 595 patients who had a good prognosis, 568 (82.01%) had received treatment with calcifediol versus the 133 patients with a poor prognosis, of whom 90 (67.66%) had received calcifediol (p < 0.001). This difference was not found for corticosteroids.

INTERPRETATION

The treatment of choice for hospitalized patients with moderate or mild COVID-19 could be calcifediol, not administering corticosteroids, until the natural history of the disease reaches a stage of hyperinflammation.

TM9SF1 offers utility as an efficient predictor of clinical severity and mortality among acute respiratory distress syndrome patients

Introduction

Acute respiratory distress syndrome (ARDS) is a major cause of death among critically ill patients in intensive care settings, underscoring the need to identify biomarkers capable of predicting ARDS patient clinical status and prognosis at an early time point. This study specifically sought to explore the utility and clinical relevance of TM9SF1 as a biomarker for the early prediction of disease severity and prognostic outcomes in patients with ARDS.

Methods

This study enrolled 123 patients with severe ARDS and 116 patients with non-severe ARDS for whom follow-up information was available. The mRNA levels of TM9SF1 and cytokines in peripheral blood mononuclear cells from these patients were evaluated by qPCR. The predictive performance of TM9SF1 and other clinical indicators was evaluated using received operating characteristic (ROC) curves. A predictive nomogram was developed based on TM9SF1 expression and evaluated for its ability in the early prediction of severe disease and mortality in patients with ARDS.

Results

TM9SF1 mRNA expression was found to be significantly increased in patients with severe ARDS relative to those with non-severe disease or healthy controls. ARDS severity increased in correspondence with the level of TM9SF1 expression (odds ratio [OR] = 2.43, 95% confidence interval [CI] = 2.15-3.72, P = 0.005), and high TM9SF1 levels were associated with a greater risk of mortality (hazard ratio [HR] = 2.27, 95% CI = 2.20-4.39, P = 0.001). ROC curves demonstrated that relative to other clinical indicators, TM9SF1 offered superior performance in the prediction of ARDS severity and mortality. A novel nomogram incorporating TM9SF1 expression together with age, D-dimer levels, and C-reactive protein (CRP) levels was developed and was used to predict ARDS severity (AUC = 0.887, 95% CI = 0.715-0.943). A separate model incorporating TM9SF1 expression, age, neutrophil-lymphocyte ratio (NLR), and D-dimer levels (C-index = 0.890, 95% CI = 0.627-0.957) was also developed for predicting mortality.

Conclusion

Increases in ARDS severity and patient mortality were observed with rising levels of TM9SF1 expression. TM9SF1 may thus offer utility as a novel biomarker for the early prediction of ARDS patient disease status and clinical outcomes.

Gut Microbiota Improves Prognostic Prediction in Critically Ill COVID-19 Patients Alongside Immunological and Hematological Indicators

The gut microbiota undergoes substantial changes in COVID-19 patients; yet, the utility of these alterations as prognostic biomarkers at the time of hospital admission, and its correlation with immunological and hematological parameters, remains unclear. The objective of this study is to investigate the gut microbiota's dynamic change in critically ill patients with COVID-19 and evaluate its predictive capability for clinical outcomes alongside immunological and hematological parameters. In this study, anal swabs were consecutively collected from 192 COVID-19 patients (583 samples) upon hospital admission for metagenome sequencing. Simultaneously, blood samples were obtained to measure the concentrations of 27 cytokines and chemokines, along with hematological and biochemical indicators. Our findings indicate a significant correlation between the composition and dynamics of gut microbiota with disease severity and mortality in COVID-19 patients. Recovered patients exhibited a higher abundance of Veillonella and denser interactions among gut commensal bacteria compared to deceased patients. Furthermore, the abundance of gut commensal bacteria exhibited a negative correlation with the concentration of proinflammatory cytokines and organ damage markers. The gut microbiota upon admission showed moderate prognostic prediction ability with an AUC of 0.78, which was less effective compared to predictions based on immunological and hematological parameters (AUC 0.80 and 0.88, respectively). Noteworthy, the integration of these three datasets yielded a higher predictive accuracy (AUC 0.93). Our findings suggest the gut microbiota as an informative biomarker for COVID-19 prognosis, augmenting existing immune and hematological indicators.

Cardioprotective effects of vaccination in hospitalized patients with COVID-19

COVID-19 vaccination has been shown to prevent and reduce the severity of COVID-19 disease. The aim of this study was to explore the cardioprotective effect of COVID-19 vaccination in hospitalized COVID-19 patients. In this retrospective, single-center cohort study, we included hospitalized COVID-19 patients with confirmed vaccination status from July 2021 to February 2022. We assessed outcomes such as acute cardiac events and cardiac biomarker levels through clinical and laboratory data. Our analysis covered 167 patients (69% male, mean age 58 years, 42% being fully vaccinated). After adjustment for confounders, vaccinated hospitalized COVID-19 patients displayed a reduced relative risk for acute cardiac events (RR: 0.33, 95% CI [0.07; 0.75]) and showed diminished troponin T levels (Cohen's d: - 0.52, 95% CI [- 1.01; - 0.14]), compared to their non-vaccinated peers. Type 2 diabetes (OR: 2.99, 95% CI [1.22; 7.35]) and existing cardiac diseases (OR: 4.31, 95% CI [1.83; 10.74]) were identified as significant risk factors for the emergence of acute cardiac events. Our findings suggest that COVID-19 vaccination may confer both direct and indirect cardioprotective effects in hospitalized COVID-19 patients.

Immunohistochemical and Morphometric Analysis of Lung Tissue in Fatal COVID-19

The primary targets of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the lungs are type I pneumocytes, macrophages, and endothelial cells. We aimed to identify lung cells targeted by SARS-CoV-2 using viral nucleocapsid protein staining and morphometric features on patients with fatal COVID-19. We conducted a retrospective analysis of fifty-one autopsy cases of individuals who tested positive for SARS-CoV-2. Demographic and clinical information were collected from forensic reports, and lung tissue was examined for microscopic lesions and the presence of specific cell types. Half of the evaluated cohort were older than 71 years, and the majority were male (74.5%). In total, 24 patients presented diffuse alveolar damage (DAD), and 50.9% had comorbidities (56.9% obesity, 33.3% hypertension, 15.7% diabetes mellitus). Immunohistochemical analysis showed a similar pattern of infected macrophages, infected type I pneumocytes, and endothelial cells, regardless of the presence of DAD (p > 0.5). The immunohistochemical reactivity score (IRS) was predominantly moderate but without significant differences between patients with and without DAD (p = 0.633 IRS for type I pneumocytes, p = 0.773 IRS for macrophage, and p = 0.737 for IRS endothelium). The nucleus/cytoplasm ratio shows lower values in patients with DAD (median: 0.29 vs. 0.35), but the difference only reaches a tendency for statistical significance (p = 0.083). Our study confirms the presence of infected macrophages, type I pneumocytes, and endothelial cells with a similar pattern in patients with and without diffuse alveolar damage.

Human surfactant protein A inhibits SARS-CoV-2 infectivity and alleviates lung injury in a mouse infection model

Introduction

SARS coronavirus 2 (SARS-CoV-2) infects human angiotensin-converting enzyme 2 (hACE2)-expressing lung epithelial cells through its spike (S) protein. The S protein is highly glycosylated and could be a target for lectins. Surfactant protein A (SP-A) is a collagen-containing C-type lectin, expressed by mucosal epithelial cells and mediates its antiviral activities by binding to viral glycoproteins.

Objective

This study examined the mechanistic role of human SP-A in SARS-CoV-2 infectivity and lung injury in vitro and in vivo.

Results

Human SP-A can bind both SARS-CoV-2 S protein and hACE2 in a dose-dependent manner (p<0.01). Pre-incubation of SARS-CoV-2 (Delta) with human SP-A inhibited virus binding and entry and reduced viral load in human lung epithelial cells, evidenced by the dose-dependent decrease in viral RNA, nucleocapsid protein (NP), and titer (p<0.01). We observed significant weight loss, increased viral burden, and mortality rate, and more severe lung injury in SARS-CoV-2 infected hACE2/SP-A KO mice (SP-A deficient mice with hACE2 transgene) compared to infected hACE2/mSP-A (K18) and hACE2/hSP-A1 (6A2) mice (with both hACE2 and human SP-A1 transgenes) 6 Days Post-infection (DPI). Furthermore, increased SP-A level was observed in the saliva of COVID-19 patients compared to healthy controls (p<0.05), but severe COVID-19 patients had relatively lower SP-A levels than moderate COVID-19 patients (p<0.05).

Discussion

Collectively, human SP-A attenuates SARS-CoV-2-induced acute lung injury (ALI) by directly binding to the S protein and hACE2, and inhibiting its infectivity; and SP-A level in the saliva of COVID-19 patients might serve as a biomarker for COVID-19 severity.

IL-6 and SAA-Strong Predictors for the Outcome in COVID-19 CKD Patients

In this prospective study, we assessed biomarkers of inflammation (IL-6 and SAA) from the serum of 120 COVID-19 patients, of whom 70 had chronic kidney disease. All the samples were taken at emergency-department (ED) admission. Our goal was to relate the biomarkers to the results of death and acute kidney injury. All the patients underwent chest computer tomography to estimate the severity score (0-5), which was performed at hospital admission. Finally, biomarkers were also evaluated in a healthy control group and in non-COVID-19-CKD patients. IL-6 and SAA were statistically different between the subgroups, i.e., they were significantly increased in patients with COVID-19. Both of the biomarkers (IL-6 and SAA) were independently associated with mortality, AKI and a higher grade of pathological changes in the lung's parenchyma. Both high baseline levels of IL-6 and SAA on hospital admission were highly correlated with a later ventilatory requirement and mortality, independent of hospital stay. Mortality was found to be significantly higher when the chest CT severity score was 3-4, compared with a severity score of 0-2 (p < 0.0001). Conclusions: at the admission stage, IL-6 and SAA are useful markers for COVID-19 patients with CKD.

Multi-organ microphysiological system: A new paradigm for COVID-19 research

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2, is a systemic disease with a broad spectrum of manifestations in multiple organs. Till now, it remains unclear whether these multi-organ dysfunctions arise from direct viral infection, or indirect injuries. There is an urgent need to evaluate the impacts of SARS-CoV-2 infection on human bodies and explore the pathogenesis of extrapulmonary organ injuries at a systemic level. Multi-organ microphysiological systems, which can model whole-body physiology with engineered tissues and physiological communications between different organs, serve as powerful platforms to model COVID-19 in a multi-organ manner. In this perspective, we summarize the recent advancement in multi-organ microphysiological system-based researches, discuss the remaining challenges, and proposed some prospects in the application of multi-organ model system for COVID-19 research.

Angiotensin-(1-7) attenuates SARS-CoV2 spike protein-induced interleukin-6 and interleukin-8 production in alveolar epithelial cells through activation of Mas receptor

BACKGROUND

SARS-CoV-2 spike proteins (SP) can bind to the human angiotensin-converting enzyme 2 (ACE2) in human pulmonary alveolar epithelial cells (HPAEpiC) and trigger an inflammatory process. Angiotensin-(1-7) may have an anti-inflammatory effect through activation of Mas receptor. This study aims to investigate whether SARS-CoV-2 SP can induce inflammation through ACE2 in the alveolar epithelial cells which can be modulated through angiotensin-(1-7)/Mas receptor axis.

METHODS

HPAEpiC were treated with SARS-CoV-2 SP in the presence or absence of ACE2 antagonist-dalbavancin and Mas receptor agonist-angiotensin-(1-7). Proinflammatory cytokine production (IL-6 and IL-8) were measured at mRNA and protein levels. MAP kinase phosphorylation and transcription factor activation was determined by Western Blot. Mas receptor was blocked by either antagonist (A779) or knockdown (specific SiRNA). Experiments were replicated using A549 cells.

FINDINGS

SARS-CoV-2 SP (5 μg/mL) significantly induced MAP kinase (ERK1/2) phosphorylation, downstream transcription factor (activator protein-1, AP-1) activation and cytokine production (IL-6 and IL-8) at both mRNA and protein levels. Pretreatment with dalbavancin (10 μg/mL), or angiotensin-(1-7) (10 μM) significantly reduced ERK1/2 phosphorylation, AP-1 activation, and cytokine production. However, these angiotensin-(1-7)-related protective effects were significantly abolished by blocking Mas receptor with either antagonist (A799,10 μM) or SiRNA knockdown.

INTERPRETATION

SARS-CoV-2 SP can induce proinflammatory cytokine production, which can be inhibited by either ACE2 antagonist or Mas receptor agonist-angiotensin-(1-7). Angiotensin-(1-7)-related protective effect on cytokine reduction can be abolished by blocking Mas receptor. Our findings suggest that ACE2/angiotensin-(1-7)/Mas axis may serve as a therapeutic target to control inflammatory response triggered by SARS-CoV-2 SP.

SARS-CoV-2 N protein induced acute kidney injury in diabetic db/db mice is associated with a Mincle-dependent M1 macrophage activation

"Cytokine storm" is common in critically ill COVID-19 patients, however, mechanisms remain largely unknown. Here, we reported that overexpression of SARS-CoV-2 N protein in diabetic db/db mice significantly increased tubular death and the release of HMGB1, one of the damage-associated molecular patterns (DAMPs), to trigger M1 proinflammatory macrophage activation and production of IL-6, TNF-α, and MCP-1 via a Mincle-Syk/NF-κB-dependent mechanism. This was further confirmed in vitro that overexpression of SARS-CoV-2 N protein caused the release of HMGB1 from injured tubular cells under high AGE conditions, which resulted in M1 macrophage activation and production of proinflammatory cytokines via a Mincle-Syk/NF-κB-dependent mechanism. This was further evidenced by specifically silencing macrophage Mincle to block HMGB1-induced M1 macrophage activation and production of IL-6, TNF-α, and MCP-1 in vitro. Importantly, we also uncovered that treatment with quercetin largely improved SARS-CoV-2 N protein-induced AKI in db/db mice. Mechanistically, we found that quercetin treatment significantly inhibited the release of a DAMP molecule HMGB1 and inactivated M1 pro-inflammatory macrophage while promoting reparative M2 macrophage responses by suppressing Mincle-Syk/NF-κB signaling in vivo and in vitro. In conclusion, SARS-CoV-2 N protein-induced AKI in db/db mice is associated with Mincle-dependent M1 macrophage activation. Inhibition of this pathway may be a mechanism through which quercetin inhibits COVID-19-associated AKI.

Hydrogen sulfide: From a toxic gas to a potential therapy for COVID-19 and inflammatory disorders

COVID-19 has been shown to induce inflammatory disorders and CNS manifestations. Swift and efficient treatment strategies are urgently warranted for the management of COVID, inflammatory and neurological disorders. Hydrogen sulfide (H2S) has been associated with several clinical disorders due to its potential to influence a broad range of biological signalling pathways. According to recent clinical studies, COVID patients with lower physiological H2S had higher fatality rates. These findings clearly demonstrate an inverse correlation between H2S levels and the severity of COVID-19. H2S has been proposed as a protective molecule because of its antioxidant, anti-inflammatory, and antiviral properties. Various H2S-releasing prodrugs, hybrids and natural compounds have been tested for their therapeutic efficacy in viral infections and inflammatory disorders. In this review, I am highlighting the rationale for using H2S-based interventions for the management of COVID-19 and post-infection inflammatory disorders including neuroinflammation. I am also proposing therepurposing of existing H2S-releasing prodrugs, developing new NO-H2S-hybrids, targeting H2S metabolic pathways, and using H2S-producing dietary supplements as viable defensive strategies against SARS-CoV-2 infection and COVID-19 pathologies.

Apoptotic cells for treatment of acute respiratory distress syndrome associated with COVID-19

Background

Hyper-inflammatory immune response, a hallmark of severe COVID-19, is associated with increased mortality. Acute respiratory distress syndrome (ARDS) is a common manifestation. We undertook two phase I/II studies in five and then 16 subjects with severe/critical COVID-19 to assess the safety and preliminary efficacy of apoptotic cells (Allocetra™-OTS, Enlivex Therapeutics), a cellular immunomodulatory therapy that reprograms macrophages to reduce hyper-inflammatory response severity.

Methods

Eligible patients presenting to the Emergency Room with severe COVID-19 and respiratory dysfunction received one intravenous administration of Allocetra™-OTS and were monitored for adverse events (AEs) for 28 days. The primary aim was to determine the safety profile of treatment; secondary aims were recovery from ARDS, intensive care unit (ICU) and hospital length-of-stay, and mortality. Immune modulator markers were measured to elucidate the mechanism of action of Allocetra™-OTS.

Results

21 patients with severe-critical COVID-19 of Gamma, Alpha and Delta variants, were treated with a single dose of apoptotic cells. 19/21 patients had mild-to-severe ARDS at presentation. Median age was 53 years, 16/21 were males, 16/21 were overweight/obese. No serious related adverse events (SAEs) were reported. All 21 study subjects survived to day 28 (end of study); 19/21 recovered completely. Comparable mortality rates at the hospital were 3.8%-8.9% for age- and gender-matched patients, and 39%-55% for critical patients. Recovering patients exhibited rapid ARDS resolution and parallel resolution of inflammation markers and elevated cytokines/chemokines.

Conclusion

In patients with severe/critical COVID-19 associated with ARDS, Allocetra™-OTS was safe, well-tolerated, and showed promising results for resolution of respiratory failure and inflammation.

Trial registration

https://clinicaltrials.gov/ct2/show/study/NCT04513470, https://clinicaltrials.gov/ct2/show/study/NCT04590053, Identifiers NCT04513470, NCT04590053.

Fatigue in Post-Acute Sequelae of Coronavirus Disease 2019

Fatigue from post-acute sequelae of coronavirus disease 2019 is a complex constellation of symptoms that could be driven by a wide spectrum of underlying etiologies. Despite this, there seems to be hope for treatment plans that focus on addressing possible etiologies and creating a path to improving quality of life and a paced return to activity.

The multifaceted nature of IL-10: regulation, role in immunological homeostasis and its relevance to cancer, COVID-19 and post-COVID conditions

Interleukin-10 (IL-10) is a pleiotropic cytokine that has a fundamental role in modulating inflammation and in maintaining cell homeostasis. It primarily acts as an anti-inflammatory cytokine, protecting the body from an uncontrolled immune response, mostly through the Jak1/Tyk2 and STAT3 signaling pathway. On the other hand, IL-10 can also have immunostimulating functions under certain conditions. Given the pivotal role of IL-10 in immune modulation, this cytokine could have relevant implications in pathologies characterized by hyperinflammatory state, such as cancer, or infectious diseases as in the case of COVID-19 and Post-COVID-19 syndrome. Recent evidence proposed IL-10 as a predictor of severity and mortality for patients with acute or post-acute SARS-CoV-2 infection. In this context, IL-10 can act as an endogenous danger signal, released by tissues undergoing damage in an attempt to protect the organism from harmful hyperinflammation. Pharmacological strategies aimed to potentiate or restore IL-10 immunomodulatory action may represent novel promising avenues to counteract cytokine storm arising from hyperinflammation and effectively mitigate severe complications. Natural bioactive compounds, derived from terrestrial or marine photosynthetic organisms and able to increase IL-10 expression, could represent a useful prevention strategy to curb inflammation through IL-10 elevation and will be discussed here. However, the multifaceted nature of IL-10 has to be taken into account in the attempts to modulate its levels.

Impact of Negative Fluid Balance on Mortality and Outcome of Patients with Confirmed COVID-19

Purpose

Maintaining the proper fluid balance is a fundamental step in the management of hospitalized patients. The current study evaluated the impact of negative fluid balance on outcomes of patients with confirmed COVID-19.

Methods

We considered the negative fluid balance as a higher output fluid compared to the input fluid. The fluid balance was categorized into four groups (group 4: -850 to -500 ml/day; group 3: -499 to -200 ml/day, group 2: -199 to 0 ml/day, and group 1 : 1 to 1000 ml/day) and included ordinally in the model. The outcomes were all-cause mortality, length of hospitalization, and improvement in oxygen saturation.

Results

The fluid balance differed significantly among nonsurvivors and survivors (MD: -317.93, 95% CI: -410.21, -225.69, and p < 0.001). After adjusting for potential confounders, there was a significantly lower frequency of mortality in patients with negative fluid balance compared to the controls (aRR: 0.69, 95% CI: 0.57, 0.84, and p < 0.001). Similarly, the length of hospitalization was significantly shorter in the negative fluid balance group in comparison to the control group (aMD: -1.01, 95% CI: -1.74, -0.28, and p=0.006).

Conclusion

We determined that the negative fluid balance was associated with favorable outcomes in COVID-19 patients. The negative fluid balance was associated with the reduced mortality rate and length of hospitalization as well as improvement in oxygen saturation. Moreover, the NT-proBNP >781 pg/mL and fluid balance >-430 mL might be the predictors for positive fluid balance and mortality, respectively.

Recent progress and prospects for anti-cytokine therapy in preclinical and clinical acute lung injury

Acute respiratory distress syndrome (ARDS) is a heterogeneous cause of respiratory failure that has a rapid onset, a high mortality rate, and for which there is no effective pharmacological treatment. Current evidence supports a critical role of excessive inflammation in ARDS, resulting in several cytokines, cytokine receptors, and proteins within their downstream signalling pathways being putative therapeutic targets. However, unsuccessful trials of anti-inflammatory drugs have thus far hindered progress in the field. In recent years, the prospects of precision medicine and therapeutic targeting of cytokines coevolving into effective treatments have gained notoriety. There is an optimistic and growing understanding of ARDS subphenotypes as well as advances in treatment strategies and clinical trial design. Furthermore, large trials of anti-cytokine drugs in patients with COVID-19 have provided an unprecedented amount of information that could pave the way for therapeutic breakthroughs. While current clinical and nonclinical ARDS research suggest relatively limited potential in monotherapy with anti-cytokine drugs, combination therapy has emerged as an appealing strategy and may provide new perspectives on finding safe and effective treatments. Accurate evaluation of these drugs, however, also relies on well-founded experimental research and the implementation of biomarker-guided stratification in future trials. In this review, we provide an overview of anti-cytokine therapy for acute lung injury and ARDS, highlighting the current preclinical and clinical evidence for targeting the main cytokines individually and the therapeutic prospects for combination therapy.

Low-dose radiation therapy suppresses viral pneumonia by enhancing broad-spectrum anti-inflammatory responses via transforming growth factor-β production

Low-dose radiation therapy (LDRT) can suppress intractable inflammation, such as that in rheumatoid arthritis, and is used for treating more than 10,000 rheumatoid arthritis patients annually in Europe. Several recent clinical trials have reported that LDRT can effectively reduce the severity of coronavirus disease (COVID-19) and other cases of viral pneumonia. However, the therapeutic mechanism of LDRT remains unelucidated. Therefore, in the current study, we aimed to investigate the molecular mechanism underlying immunological alterations in influenza pneumonia after LDRT. Mice were irradiated to the whole lung 1 day post-infection. The changes in levels of inflammatory mediators (cytokines and chemokines) and immune cell populations in the bronchoalveolar lavage (BALF), lungs, and serum were examined. LDRT-treated mice displayed markedly increased survival rates and reduced lung edema and airway and vascular inflammation in the lung; however, the viral titers in the lungs were unaffected. Levels of primary inflammatory cytokines were reduced after LDRT, and transforming growth factor-β (TGF-β) levels increased significantly on day 1 following LDRT. Levels of chemokines increased from day 3 following LDRT. Additionally, M2 macrophage polarization or recruitment was increased following LDRT. We found that LDRT-induced TGF-β reduced the levels of cytokines and polarized M2 cells and blocked immune cell infiltration, including neutrophils, in BALF. LDRT-induced early TGF-β production was shown to be a key regulator involved in broad-spectrum anti-inflammatory activity in virus-infected lungs. Therefore, LDRT or TGF-β may be an alternative therapy for viral pneumonia.

Protective effects of Stephania pierrei tuber-derived oxocrebanine against LPS-induced acute lung injury in mice

Acute lung injury and acute respiratory distress syndrome (ALI/ARDS) have high mortality rates. Though corticosteroids are commonly used for the treatment of these conditions, their efficacy has not been conclusively demonstrated and their use can induce various adverse reactions. Hence, the application of corticosteroids as therapeutic modalities for ALI/ARDS is limited. Meanwhile, the aporphine alkaloid oxocrebanine isolated from Stephania pierrei tubers has demonstrated anti-inflammatory efficacy in murine/human macrophage cell lines stimulated by lipopolysaccharide (LPS). Accordingly, the primary objectives of the present study are to investigate the anti-inflammatory effects of oxocrebanine on LPS-induced murine alveolar epithelial (MLE-12) cells and its efficacy against LPS-induced murine ALI. Results show that oxocrebanine downregulates the abundance of interleukin (IL)-1beta, IL-6, and inducible nitric oxide synthase, as well as the phosphorylation of nuclear factor-kappaB (NF-κB), stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK), p38, protein kinase B (Akt), and glycogen synthase kinase-3beta signalling proteins in LPS-induced MLE-12 cells. Moreover, in a murine ALI model, oxocrebanine lowers lung injury scores and lung wet/dry weight ratios while reducing inflammatory cell infiltration. It also suppresses LPS-induced tumour necrosis factor-alpha and IL-6 in the bronchoalveolar lavage fluid and plasma. Moreover, oxocrebanine downregulates NF-κB, SAPK/JNK, p38, and Akt phosphorylation in the lung tissues of LPS-treated mice. Taken together, the foregoing results show that oxocrebanine provides significant protection against LPS-induced ALI in mice primarily by suppressing various inflammatory signalling pathways in alveolar epithelial cells and lung tissues. Hence, oxocrebanine might prove effective as an anti-inflammatory agent for the treatment of lung inflammation.

SPP1 exacerbates ARDS via elevating Th17/Treg and M1/M2 ratios through suppression of ubiquitination-dependent HIF-1α degradation

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe inflammatory pulmonary condition that leads to respiratory failure. The imbalance of Th17/Treg and M1/M2 is implicated in ARDS. A better understanding of the regulation of the balance of Th17/Treg and M1/M2 may provide novel therapeutic targets for ARDS.

METHODS

Plasma and BALF samples were collected from ARDS patients. Inflammatory cytokines were examined by ELISA. Th17, Treg, M1 and M2 were identified via immunofluorescence staining of RORγt, Foxp3, iNOS and Arg-1. H&E and Masson's trichrome staining were applied for evaluating pulmonary damage and fibrosis. A mouse model of ARDS was established through LPS administration. HIF-1α was immunoprecipitated and subjected to ubiquitination analysis via western blotting. The expression of SPP1, VHL and HIF-1α was examined by RT-qPCR and western blotting.

RESULTS

ARDS patients showed elevated levels of inflammatory cytokines and ratios of Th17/Treg and M1/M2. SPP1 was upregulated in ARDS mice, and silencing of SPP1 alleviated lung injury and fibrosis. SPP1 inhibited VHL expression to reduce the ubiquitination and degradation of HIF-1α in ARDS. Overexpression of SPP1 facilitated Th17, Treg and M1 polarization but inhibited M2 polarization through upregulation of HIF-1α.

CONCLUSION

SPP1 elevates Th17/Treg and M1/M2 ratio by suppressing VHL expression and ubiquitination-dependent HIF-1α degradation, thus exacerbating ARDS. Our study provides novel mechanistic insights into ARDS pathogenesis and promising therapeutic targets.

The association between inflammatory and immune system biomarkers and the dietary inflammatory index in patients with COVID-19

Background

Inflammation and cytokine storm have been reported to be the main cause of acute symptoms of coronavirus disease (COVID-19). Diet-induced inflammation may affect the condition of patients with COVID-19. Therefore, this study aimed to investigate the relationship between disease severity, inflammatory and immune system biomarkers, and the dietary inflammatory index (DII) in patients with COVID-19.

Methods

This cross-sectional study was conducted on 500 adult patients with COVID-19. Patients were divided into mild, moderate, and severe conditions based on clinical and laboratory evidence. A validated food frequency questionnaire (FFQ) was used to determine DII and energy-adjusted DII (E-DII) scores. The serum C-reactive protein (CRP) level and blood cell count were measured for all patients. Multiple linear regression was used to explore the association between DII and E-DII and CRP, blood cell counts, and hospitalization in patients with COVID-19.

Results

Coronavirus disease (COVID-19) patients with higher DII had higher consumption of fat and carbohydrate and lower intakes of protein, anti-inflammatory nutrients, garlic, caffeine, tea, onion, and fiber (P &lt; 0.05). There was a positive association between DII and CRP (β = 1.024, P &lt; 0.001), hospitalization (β = 1.062, P &lt; 0.001), WBC count (β = 0.486, P &lt; 0.009), neutrophil count (β = 0.565, P &lt; 0.001), and neutrophil-to-lymphocyte ratio (β = 0.538, P &lt; 0.001) and a negative association between DII and the lymphocyte count (β = −0.569, P &lt; 0.001). There was a positive association between E-DII and hospitalization (β = 1.645, P &lt; 0.001), WBC count (β = 0.417, P &lt; 0.02), and neutrophil-to-lymphocyte ratio (β = 0.35, P &lt; 0.03).

Conclusion

There is a positive correlation between DII and inflammation, immune hyperactivation, and length of hospital stay in patients with COVID-19. Further longitudinal studies are necessary.

Inhibition of a Microbiota-derived Peptide Ameliorates Established Acute Lung Injury

Acute lung injury is a clinical syndrome characterized by a diffuse lung inflammation that commonly evolves into acute respiratory distress syndrome and respiratory failure. The lung microbiota is involved in the pathogenesis of acute lung injury. Corisin, a proapoptotic peptide derived from the lung microbiota, plays a role in acute lung injury and acute exacerbation of pulmonary fibrosis. Preventive therapeutic intervention with a monoclonal anticorisin antibody inhibits acute lung injury in mice. However, whether inhibition of corisin with the antibody ameliorates established acute lung injury is unknown. Here, the therapeutic effectiveness of the anticorisin antibody in already established acute lung injury in mice was assessed. Lipopolysaccharide was used to induce acute lung injury in mice. After causing acute lung injury, the mice were treated with a neutralizing anticorisin antibody. Mice treated with the antibody showed significant improvement in lung radiological and histopathological findings, decreased lung infiltration of inflammatory cells, reduced markers of lung tissue damage, and inflammatory cytokines in bronchoalveolar lavage fluid compared to untreated mice. In addition, the mice treated with anticorisin antibody showed significantly increased expression of antiapoptotic proteins with decreased caspase-3 activation in the lungs compared to control mice treated with an irrelevant antibody. In conclusion, these observations suggest that the inhibition of corisin is a novel and promising approach for treating established acute lung injury.

Gut microbiome therapeutic modulation to alleviate drug-induced hepatic damage in COVID-19 patients

Coronavirus disease 2019 (COVID-19) infection caused by the severe acute respiratory syndrome coronavirus 2 virus, its symptoms, treatment, and post-COVID-19 effects have been a major focus of research since 2020. In addition to respiratory symptoms, different clinical variants of the virus have been associated with dynamic symptoms and multiorgan diseases, including liver abnormalities. The release of cytokines by the activation of innate immune cells during viral infection and the high doses of drugs used for COVID-19 treatment are considered major drivers of liver injury in COVID-19 patients. The degree of hepatic inflammation in patients suffering from chronic liver disease and having COVID-19 could be severe and can be estimated through different liver chemistry abnormality markers. Gut microbiota influences liver chemistry through its metabolites. Gut dysbiosis during COVID-19 treatment can promote liver inflammation. Here, we highlighted the bidirectional association of liver physiology and gut microbiota (gut-liver axis) and its potential to manipulate drug-induced chemical abnormalities in the livers of COVID-19 patients.

Cytokine levels in maternal and infant blood after COVID-19 vaccination during pregnancy in comparison with unvaccinated controls

The objective of this study was to compare maternal and infant cytokine profiles at delivery among those vaccinated against SARS-CoV-2 during pregnancy to unvaccinated controls. Mother-infant dyads were enrolled in this prospective cohort study, and maternal blood and infant and/or cord blood collected. Samples were analyzed utilizing a LEGENDplex 13-plex human anti-viral response cytokine panel. Maternal IP-10 and IFN-λ2/3 were lower in the vaccinated cohort. In the infants, levels were lower for IL-1β, IFN-λ2/3, and GM-CSF, and higher for IFN-λ1 in the vaccinated cohort. Vaccination against SARS-CoV-2 during pregnancy did not lead to elevations in cytokines in mothers or infants.

Serum and Urinary Biomarkers in COVID-19 Patients with or without Baseline Chronic Kidney Disease

In a prospective, observational, non-interventional, single-center study, we assessed various plasma and urinary biomarkers of kidney injury (neutrophil gelatinase-associated Lipocain [NGAL], kidney-injury molecule-1 [KIM-1], and interleukin-18 [IL-18]); inflammation (IL-6, C-reactive protein [CRP]); plus angiotensin converting enzyme 2 (ACE2) in 120 COVID-19 patients (of whom 70 had chronic kidney disease (CKD) at emergency-department (ED) admission). Our aim was to correlate the biomarkers with the outcomes (death, acute kidney injury [AKI]). All patients had received a chest-CT scan at admission to calculate the severity score (0–5). Biomarkers were also assessed in healthy volunteers and non-COVID-19-CKD patients. These biomarkers statistically differed across subgroups, i.e., they were significantly increased in COVID-19 patients, except for urinary (u)KIM1 and uIL-18. Amongst the biomarkers, only IL-6 was independently associated with mortality, along with AKI and not using remdesivir. Regarding the prediction of AKI, only IL-6 and uKIM1 were significantly elevated in patients presenting with AKI. However, AKI could not be predicted. Having high baseline IL-6 levels was associated with subsequent ventilation requirement and death. The mortality rate was almost 90% when the chest CT-scan severity score was 3 or 4 vs. 6.8% when the severity score was 0–2 (p < 0.0001).

Immune Dysregulation in Acute SARS-CoV-2 Infection

Introduction

Neutralizing antibodies have been shown to develop rapidly following SARS-CoV-2 infection, specifically against spike (S) protein, where cytokine release and production is understood to drive the humoral immune response during acute infection. Thus, we evaluated the quantity and function of antibodies across disease severities and analyzed the associated inflammatory and coagulation pathways to identify acute markers that correlate with antibody response following infection.

Methods

Blood samples were collected from patients at time of diagnostic SARS-CoV-2 PCR testing between March 2020-November 2020. Plasma samples were analyzed using the MesoScale Discovery (MSD) Platform using the COVID-19 Serology Kit and U-Plex 8 analyte multiplex plate to measure anti-alpha and beta coronavirus antibody concentration and ACE2 blocking function, as well as plasma cytokines.

Results

A total of 230 (181 unique patients) samples were analyzed across the 5 COVID-19 disease severities. We found that antibody quantity directly correlated with functional ability to block virus binding to membrane-bound ACE2, where a lower SARS-CoV-2 anti-spike/anti-RBD response corresponded with a lower antibody blocking potential compared to higher antibody response (anti-S1 r = 0.884, P < 0.001; anti-RBD r = 0.75, P < 0.001). Across all the soluble proinflammatory markers we examined, ICAM, IL-1β, IL-4, IL-6, TNFα, and Syndecan showed a statistically significant positive correlation between cytokine or epithelial marker and antibody quantity regardless of COVID-19 disease severity. Analysis of autoantibodies against type 1 interferon was not shown to be statistically significant between disease severity groups.

Conclusion

Previous studies have shown that proinflammatory markers, including IL-6, IL-8, IL-1β, and TNFα, are significant predictors of COVID-19 disease severity, regardless of demographics or comorbidities. Our study demonstrated that not only are these proinflammatory markers, as well as IL-4, ICAM, and Syndecan, correlative of disease severity, they are also correlative of antibody quantity and quality following SARS-CoV-2 exposure.

Hyperinflammatory Response in COVID-19: A Systematic Review

COVID-19 is a multisystemic disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The immunopathogenic conditions of the hyperinflammatory response that cause systemic inflammation are extremely linked to its severity. This research sought to review the immunopathological elements that contribute to its progression. This is a systematic review using the PUBMED, LILACS, MEDLINE, and SCIELO databases using articles between May 2020 and July 2022 with the following search terms in conjunction with "AND": "SARS-CoV-2"; "COVID-19"; "ARDS" and "Cytokine Storm". The quality appraisal and risk of bias were assessed by the JBI checklists and the Cochrane Collaboration's RoB 2.0 and ROBINS-I tools, respectively, and the risk of bias for in vitro studies by a pre-defined standard in the literature. The search resulted in 39 articles. The main actors in this response denote SARS-CoV-2 Spike proteins, cellular proteases, leukocytes, cytokines, and proteolytic cascades. The "cytokine storm" itself brings several complications to the host through cytokines such as IL-6 and chemokines (such as CCL2), which influence tissue inflammation through apoptosis and pyroptosis. The hyperinflammatory response causes several unfavorable outcomes in patients, and systemic inflammation caused largely by the dysregulation of the immune response should be controlled for their recovery.

Different cytokine and chemokine profiles in hospitalized patients with COVID-19 during the first and second outbreaks from Argentina show no association with clinical comorbidities

Background

COVID-19 severity has been linked to an increased production of inflammatory mediators called "cytokine storm". Available data is mainly restricted to the first international outbreak and reports highly variable results. This study compares demographic and clinical features of patients with COVID-19 from Córdoba, Argentina, during the first two waves of the pandemic and analyzes association between comorbidities and disease outcome with the "cytokine storm", offering added value to the field.

Methods

We investigated serum concentration of thirteen soluble mediators, including cytokines and chemokines, in hospitalized patients with moderate and severe COVID-19, without previous rheumatic and autoimmune diseases, from the central region of Argentina during the first and second infection waves. Samples from healthy controls were also assayed. Clinical and biochemical parameters were collected.

Results

Comparison between the two first COVID-19 waves in Argentina highlighted that patients recruited during the second wave were younger and showed less concurrent comorbidities than those from the first outbreak. We also recognized particularities in the signatures of systemic cytokines and chemokines in patients from both infection waves. We determined that concurrent pre-existing comorbidities did not have contribution to serum concentration of systemic cytokines and chemokines in COVID-19 patients. We also identified immunological and biochemical parameters associated to inflammation which can be used as prognostic markers. Thus, IL-6 concentration, C reactive protein level and platelet count allowed to discriminate between death and discharge in patients hospitalized with severe COVID-19 only during the first but not the second wave.

Conclusions

Our data provide information that deepens our understanding of COVID-19 pathogenesis linking demographic features of a COVID-19 cohort with cytokines and chemokines systemic concentration, presence of comorbidities and different disease outcomes. Altogether, our findings provide information not only at local level by delineating inflammatory/anti-inflammatory response of patients but also at international level addressing the impact of comorbidities and the infection wave in the variability of cytokine and chemokine production upon SARS-CoV-2 infection.

Assessment of Admission COVID-19 Associated Hyperinflammation Syndrome Score in Critically-Ill COVID-19 Patients

PURPOSE

We aimed to evaluate the relation between admission COVID-19 associated hyperinflammatory syndrome (cHIS) score and intensive care unit (ICU) outcomes.

MATERIALS AND METHODS

Patients with laboratory confirmed COVID-19 admitted to our ICU between 20^th March 2020-15^th June 2021 were included. Patients who received immunomodulatory treatment except corticosteroids were excluded. Main outcomes were ICU mortality and invasive mechanical ventilation (IMV) requirement after ICU admission.

RESULTS

Three hundred and seventy patients with a median (IQR) age of 66 (56-77) were analyzed. Median admission cHIS score was 3 (2-4). A cHIS score ≥3 was found to be associated with ICU mortality (sensitivity = 0.63, specificity = 0.50; p < 0.01) and IMV requirement after ICU admission (sensitivity = 0.61, specificity = 0.51; p < 0.01). Patients with an admission cHIS score ≥3 (n = 199) had worse median admission APACHEII, SOFA scores and PaO₂/FiO₂ ratio than others (n = 171) (p < 0.01). IMV requirement after ICU admission (38.5% vs 26.1%;p = 0.03), ICU (36.2% vs 25.1%;p = 0.02), hospital (39.1% vs 26.9%;p = 0.01) and 28th day (28.1% vs 19.1%;p = 0.04) mortality were higher in patients with admission cHIS score ≥3 than others (p < 0.01). Age <65 years, malignancy and higher admission SOFA score were independent variables associated with admission cHIS score ≥3.

CONCLUSION

Critically-ill COVID-19 patients with admission cHIS score ≥3 have worse disease severity and outcomes than other patients.

COVID-19 and Acute Kidney Injury - Direct and Indirect Pathophysiological Mechanisms Underlying Lesion Development

COVID-19 is a pandemic disease caused by the SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) responsible for millions of deaths worldwide. Although the respiratory system is the main target of COVID-19, the disease can affect other organs, including the kidneys. Acute Kidney Injury (AKI), commonly seen in patients infected with COVID-19, has a multifactorial cause. Several studies associate this injury with the direct involvement of the virus in renal cells and the indirect damage stimulated by the infection. The direct cytopathic effects of SARS-CoV-2 are due to the entry and replication of the virus in renal cells, changing several regulatory pathways, especially the renin-angiotensin-aldosterone system (RAAS), with repercussions on the kallikrein-kinin system (KKS). Furthermore, the virus can deregulate the immune system, leading to an exaggerated response of inflammatory cells, characterizing the state of hypercytokinemia. The such exaggerated inflammatory response is commonly associated with hemodynamic changes, reduced renal perfusion, tissue hypoxia, generation of reactive oxygen species (ROS), endothelial damage, and coagulopathies, which can result in severe damage to the renal parenchyma. Thereby, understanding the molecular mechanisms and pathophysiology of kidney injuries induced by SARS-COV-2 is of fundamental importance to obtaining new therapeutic insights for the prevention and management of AKI.

Growth Arrest of Alveolar Cells in Response to Cytokines from Spike S1-Activated Macrophages: Role of IFN-γ

Acute respiratory distress syndrome (ARDS) is characterized by severe hypoxemia and high-permeability pulmonary edema. A hallmark of the disease is the presence of lung inflammation with features of diffuse alveolar damage. The molecular pathogenetic mechanisms of COVID-19-associated ARDS (CARDS), secondary to SARS-CoV-2 infection, are still not fully understood. Here, we investigate the effects of a cytokine-enriched conditioned medium from Spike S1-activated macrophage on alveolar epithelial A549 cells in terms of cell proliferation, induction of autophagy, and expression of genes related to protein degradation. The protective effect of baricitinib, employed as an inhibitor of JAK-STAT, has been also tested. The results obtained indicate that A549 exhibits profound changes in cell morphology associated to a proliferative arrest in the G0/G1 phase. Other alterations occur, such as a blockade of protein synthesis and the activation of autophagy, along with an increase of the intracellular amino acids content, which is likely ascribable to the activation of protein degradation. These changes correlate to the induction of IFN-regulatory factor 1 (IRF-1) due to an increased secretion of IFN-γ in the conditioned medium from S1-activated macrophages. The addition of baricitinib prevents the observed effects. In conclusion, our findings suggest that the IFN-γ-IRF-1 signaling pathway may play a role in the alveolar epithelial damage observed in COVID-19-related ARDS.

Pyridostigmine reduces mortality of patients with severe SARS-CoV-2 infection: A phase 2/3 randomized controlled trial

Background:

Respiratory failure in severe coronavirus disease 2019 (COVID-19) is associated with a severe inflammatory response. Acetylcholine (ACh) reduces systemic inflammation in experimental bacterial and viral infections. Pyridostigmine increases the half-life of endogenous ACh, potentially reducing systemic inflammation. We aimed to determine if pyridostigmine decreases a composite outcome of invasive mechanical ventilation (IMV) and death in adult patients with severe COVID-19.

Methods:

We performed a double-blinded, placebo-controlled, phase 2/3 randomized controlled trial of oral pyridostigmine (60 mg/day) or placebo as add-on therapy in adult patients admitted due to confirmed severe COVID-19 not requiring IMV at enrollment. The primary outcome was a composite of IMV or death by day 28. Secondary outcomes included reduction of inflammatory markers and circulating cytokines, and 90-day mortality. Adverse events (AEs) related to study treatment were documented and described.

Results:

We recruited 188 participants (94 per group); 112 (59.6%) were men; the median (IQR) age was 52 (44–64) years. The study was terminated early due to a significant reduction in the primary outcome in the treatment arm and increased difficulty with recruitment. The primary outcome occurred in 22 (23.4%) participants in the placebo group vs. 11 (11.7%) in the pyridostigmine group (hazard ratio, 0.47, 95% confidence interval 0.24–0.9; P = 0.03). This effect was driven by a reduction in mortality (19 vs. 8 deaths, respectively).

Conclusion:

Our data indicate that adding pyridostigmine to standard care reduces mortality among patients hospitalized for severe COVID-19.

Role of SARS-CoV-2-induced Cytokine Storm in Multi-Organ Failure: Molecular Pathways and Potential Therapeutic Options

Coronavirus disease 2019 (COVID-19) outbreak has become a global public health emergency and has led to devastating results. Mounting evidence proposes that the disease causes severe pulmonary involvement and influences different organs, leading to a critical situation named multi-organ failure. It is yet to be fully clarified how the disease becomes so deadly in some patients. However, it is proven that a condition called “cytokine storm” is involved in the deterioration of COVID-19. Although beneficial, sustained production of cytokines and overabundance of inflammatory mediators causing cytokine storm can lead to collateral vital organ damages. Furthermore, cytokine storm can cause post-COVID-19 syndrome (PCS), an important cause of morbidity after the acute phase of COVID-19. Herein, we aim to explain the possible pathophysiology mechanisms involved in COVID-19-related cytokine storm and its association with multi-organ failure and PCS. We also discuss the latest advances in finding the potential therapeutic targets to control cytokine storm wishing to answer unmet clinical demands for treatment of COVID-19.

The JAK1/2 Inhibitor Baricitinib Mitigates the Spike-Induced Inflammatory Response of Immune and Endothelial Cells In Vitro

The purpose of this study was to examine the effect of the JAK-STAT inhibitor baricitinib on the inflammatory response of human monocyte-derived macrophages (MDM) and endothelial cells upon exposure to the spike S1 protein from SARS-CoV-2. The effect of the drug has been evaluated on the release of cytokines and chemokines from spike-treated MDM, as well as on the activation of endothelial cells (HUVECs) after exposure to conditioned medium collected from spike-activated MDM. Results obtained indicate that, in MDM, baricitinib prevents the S1-dependent phosphorylation of STAT1 and STAT3, along with the induction of IP-10- and MCP-1 secretion; the release of IL-6 and TNFα is also reduced, while all other mediators tested (IL-1β, IL-8, RANTES, MIP-1α and MIP-1β) are not modified. Baricitinib is, instead, poorly effective on endothelial activation when HUVECs are exposed to supernatants from S1-activated macrophages; the induction of VCAM-1, indeed, is not affected by the drug, while that of ICAM-1 is only poorly inhibited. The drug, however, also exerts protective effects on the endothelium by limiting the expression of pro-inflammatory mediators, specifically IL-6, RANTES and IP-10. No effect of baricitinib has been observed on IL-8 synthesis and, consistently, on neutrophils chemiotaxis. Our in vitro findings reveal that the efficacy of baricitinib is limited, with effects mainly focused on the inhibition of the IL-6-mediated inflammatory loop.

Vandetanib Blocks the Cytokine Storm in SARS-CoV-2-Infected Mice

The portfolio of SARS-CoV-2 small molecule drugs is currently limited to a handful that are either approved (remdesivir), emergency approved (dexamethasone, baricitinib, paxlovid, and molnupiravir), or in advanced clinical trials. Vandetanib is a kinase inhibitor which targets the vascular endothelial growth factor receptor (VEGFR), the epidermal growth factor receptor (EGFR), as well as the RET-tyrosine kinase. In the current study, it was tested in different cell lines and showed promising results on inhibition versus the toxic effect on A549-hACE2 cells (IC50 0.79 μM) while also showing a reduction of >3 log TCID50/mL for HCoV-229E. The in vivo efficacy of vandetanib was assessed in a mouse model of SARS-CoV-2 infection and statistically significantly reduced the levels of IL-6, IL-10, and TNF-α and mitigated inflammatory cell infiltrates in the lungs of infected animals but did not reduce viral load. Vandetanib also decreased CCL2, CCL3, and CCL4 compared to the infected animals. Vandetanib additionally rescued the decreased IFN-1β caused by SARS-CoV-2 infection in mice to levels similar to that in uninfected animals. Our results indicate that the FDA-approved anticancer drug vandetanib is worthy of further assessment as a potential therapeutic candidate to block the COVID-19 cytokine storm.

Development of a physiomimetic model of acute respiratory distress syndrome by using ECM hydrogels and organ-on-a-chip devices

Acute Respiratory Distress Syndrome is one of the more common fatal complications in COVID-19, characterized by a highly aberrant inflammatory response. Pre-clinical models to study the effect of cell therapy and anti-inflammatory treatments have not comprehensively reproduced the disease due to its high complexity. This work presents a novel physiomimetic in vitro model for Acute Respiratory Distress Syndrome using lung extracellular matrix-derived hydrogels and organ-on-a-chip devices. Monolayres of primary alveolar epithelial cells were cultured on top of decellullarized lung hydrogels containing primary lung mesenchymal stromal cells. Then, cyclic stretch was applied to mimic breathing, and an inflammatory response was induced by using a bacteriotoxin hit. Having simulated the inflamed breathing lung environment, we assessed the effect of an anti-inflammatory drug (i.e., dexamethasone) by studying the secretion of the most relevant inflammatory cytokines. To better identify key players in our model, the impact of the individual factors (cyclic stretch, decellularized lung hydrogel scaffold, and the presence of mesenchymal stromal cells) was studied separately. Results showed that developed model presented a more reduced inflammatory response than traditional models, which is in line with what is expected from the response commonly observed in patients. Further, from the individual analysis of the different stimuli, it was observed that the use of extracellular matrix hydrogels obtained from decellularized lungs had the most significant impact on the change of the inflammatory response. The developed model then opens the door for further in vitro studies with a better-adjusted response to the inflammatory hit and more robust results in the test of different drugs or cell therapy.

Comparison of acute respiratory distress syndrome in patients with COVID-19 and influenza A (H7N9) virus infection

OBJECTIVES

We aimed to compared the clinical features of acute respiratory distress syndrome (ARDS) induced by COVID-19 and H7N9 virus infections.

METHODS

Clinical data of 100 patients with COVID-19 and 46 patients with H7N9 were retrospectively analyzed.

RESULTS

Elevated inflammatory indices and coagulation disorders were more common in COVID-19-ARDS group than in the H7N9-ARDS group. The median interval from illness onset to ARDS development was shorter in H7N9-ARDS. The PaO₂/FiO₂ level was lower in H7N9-ARDS, whereas the Sepsis-related Organ Failure Assessment score was higher in COVID-19-ARDS. The proportion of patients with disseminated intravascular coagulation and liver injury in COVID-19-ARDS and H7N9-ARDS was 45.5% versus 3.1% and 28.8% versus 50%, respectively (P <0.05). The mean interval from illness onset to death was shorter in H7N9-ARDS. A total of 59.1% patients with H7N9-ARDS died of refractory hypoxemia compared with 28.9% with COVID-19-ARDS (P = 0.014). Patients with COVID-19-ARDS were more likely to die of septic shock and multiple organ dysfunction compared with H7N9-ARDS (71.2% vs 36.4%, P = 0.005).

CONCLUSION

Patients with H7N9 were more susceptible to develop severe ARDS and showed a more acute disease course. COVID-19-ARDS was associated with severe inflammatory response and coagulation dysfunction, whereas liver injury was more common in H7N9-ARDS. The main causes of death between patients with the two diseases were different.

Cytokine Storm Signature in Patients with Moderate and Severe COVID-19

Hypercytokinemia, found in SARS-CoV-2 infection, contributes to multiple organ dysfunctions with acute respiratory distress syndrome, shock etc. The aim of this study was to describe cytokine storm signatures in patients with acute COVID-19 and to investigate their influence on severity of the infection. Plasma levels of 47 cytokines were investigated in 73 patients with moderate and severe COVID-19 (41 and 32, respectively) and 11 healthy donors (HD). The most elevated levels comparing patients and the HD were observed for seven pro-inflammatory cytokines (IL-6, IL-8, IL-15, IL-18, IL-27, IFNγ, TNFα), three chemokines (GROα, IP-10, MIG), two anti-inflammatory cytokines (IL-1RA, IL-10), and two growth factors (G-CSF, M-CSF). The patients with severe disease had significantly higher levels of FGF-2/FGF-basic, IL-1β, and IL-7 compared to the HD. The two groups of patients differed from each other only based on the levels of EGF, eotaxin, and IL-12 p40. Pneumonia lung injury, characterized by computer tomography, positively correlated with levels of EGF, IP-10, MCP-3 levels and negatively with IL-12 p40. Pro-inflammatory factors including IL-6, TNFα, and IP-10 negatively correlated with the frequency of the circulating T-helper17-like cells (Th17-like) and follicular Th cells that are crucial to develop SARS-CoV-2-specific plasma cells and memory B cells. Obtained data on the cytokine levels illustrate their influence on progression and severity of COVID-19.

Pyronaridine Protects against SARS-CoV-2 Infection in Mouse

There are currently relatively few small-molecule antiviral drugs that are either approved or emergency-approved for use against severe acute respiratory coronavirus 2 (SARS-CoV-2). One of these is remdesivir, which was originally repurposed from its use against Ebola. We evaluated three molecules we had previously identified computationally with antiviral activity against Ebola and Marburg and identified pyronaridine, which inhibited the SARS-CoV-2 replication in A549-ACE2 cells. The in vivo efficacy of pyronaridine has now been assessed in a K18-hACE transgenic mouse model of COVID-19. Pyronaridine treatment demonstrated a statistically significant reduction of viral load in the lungs of SARS-CoV-2-infected mice, reducing lung pathology, which was also associated with significant reduction in the levels of pro-inflammatory cytokines/chemokine and cell infiltration. Pyronaridine inhibited the viral PLpro activity in vitro (IC50 of 1.8 μM) without any effect on Mpro, indicating a possible molecular mechanism involved in its ability to inhibit SARS-CoV-2 replication. We have also generated several pyronaridine analogs to assist in understanding the structure activity relationship for PLpro inhibition. Our results indicate that pyronaridine is a potential therapeutic candidate for COVID-19.

Evaluation of interleukin-38 levels in serum of patients with coronavirus disease 2019

Interleukin‐38 (IL‐38) has recently been considered as a cytokine with anti‐inflammatory properties in viral respiratory infections, particularly coronavirus disease 19 (COVID‐19), but the evidence has not been well elucidated. Therefore, a case‐control study was conducted to determine IL‐38 serum levels in 148 patients with COVID‐19 (45 moderate, 55 severe, and 48 critical) and 113 controls. Results demonstrated that IL‐38 levels did not show significant differences between patients and controls (68.7 [interquartile range: 62.7–75.6] vs. 67.7 [58.0–82.6] pg/ml; probability = 0.457). Similarly, patients stratified by disease severity, age group, gender, or chronic disease showed no significant differences between IL‐38 levels in each stratum. Whereas, overweight/obese patients had a significantly lower median of IL‐38 compared to normal‐weight patients. Further, IL‐38 showed significantly higher levels in the age group ≥50 years of patients with critical illness than in the age group <50 years. Female patients with severe disease also showed significantly elevated levels of IL‐38 compared to male patients. In conclusion, the study indicated that serum IL‐38 levels were not affected by COVID‐19 infection, but the distribution of patients according to disease severity, age, gender, and body mass index may better reveal the role of IL‐38 in disease pathogenesis.

CYTOKINES AS POTENTIAL MARKERS OF COVID-19 SEVERITY AND OUTCOMES

The continual propagation of SARS-CoV-2 has changed health care systems globally. Ranging degrees of clinical severity in COVID-19 patients have been noted in numerous literature sources. Cytokines play a crucial role in the development of key immunological processes in COVID-19. SARS-CoV-2 causes imbalance of the immune system and might culminate in cytokine storm and multiple organ involvement. The prevailing role of some special cytokines might serve as indicators of disease severity. Further stratification of patients in the context of specific cytokines can be beneficial for diagnosing disease stages. It can prevent critical states owing to timely diagnosis and targeted therapy. Targeting peculiar cytokines can markedly reduce complications. The aim of this article is to comprehensively overview the role of the main cytokines in COVID-19 pathogenesis and distinguish prognostic factors. Insights into specific cytokine involvement in COVID-19 pathogenesis may open new avenues for diagnosing hyperinflammatory COVID-19, predicting its outcomes and providing individualized cytokine-targeted therapeutic approaches.

TNFRSF1B and TNF variants are associated with differences in soluble TNF receptors' levels in patients with severe COVID-19

BACKGROUND

The impact of genetic variants in the expression of TNF-α and its receptors in COVID-19 severity has not been previously explored. We evaluated the association of TNF (rs1800629 and rs361525), TNFRSF1A (rs767455 and rs1800693), and TNFRSF1B (rs1061622 and rs3397) variants with COVID-19 severity, assessed as invasive mechanical ventilation (IMV) requirement, and the plasma levels of soluble TNF-α, TNFR1, and TNFR2 in patients with severe COVID-19.

METHODS

The genetic study included 1,353 patients. Taqman assays assessed the genetic variants. ELISA determined the soluble TNF, TNFR1, and TNFR2 in plasma samples from 334 patients.

RESULTS

Patients carrying TT (TNFRSF1B rs3397) exhibited lower PaO2/FiO2 levels than those with CT+CC genotypes. Differences in plasma levels of TNFR1 and TNFR2 were observed according to the genotype of TNFRSF1B rs1061622, TNF rs1800629, and rs361525. According to the studied genetic variants, there were no differences in the soluble TNF-α levels. Higher soluble TNFR1 and TNFR2 levels were detected in patients with COVID-19 requiring IMV.

CONCLUSION

Genetic variants in TNF and TNFRSFB1 influence the plasma levels of soluble TNFR1 and TNFR2, implicated in the COVID-19 severity.

Immune-Mediated Inflammatory Responses of Alveolar Epithelial Cells: Implications for COVID-19 Lung Pathology

Background. Clinical and experimental evidence point to a dysregulated immune response caused by SARS-CoV-2 as the primary mechanism of lung disease in COVID-19. However, the pathogenic mechanisms underlying COVID-19-associated ARDS (Acute Respiratory Distress Syndrome) remain incompletely understood. This study aims to explore the inflammatory responses of alveolar epithelial cells to either the spike S1 protein or to a mixture of cytokines secreted by S1-activated macrophages. Methods and Results. The exposure of alveolar A549 cells to supernatants from spike-activated macrophages caused a further release of inflammatory mediators, with IL-8 reaching massive concentrations. The investigation of the molecular pathways indicated that NF-kB is involved in the transcription of IP-10 and RANTES, while STATs drive the expression of all the cytokines/chemokines tested, with the exception of IL-8 which is regulated by AP-1. Cytokines/chemokines produced by spike-activated macrophages are also likely responsible for the observed dysfunction of barrier integrity in Human Alveolar Epithelial Lentivirus-immortalized cells (hAELVi), as demonstrated by an increased permeability of the monolayers to mannitol, a marked decrease of TEER and a disorganization of claudin-7 distribution. Conclusion. Upon exposure to supernatants from S1-activated macrophages, A549 cells act both as targets and sources of cytokines/chemokines, suggesting that alveolar epithelium along with activated macrophages may orchestrate lung inflammation and contribute to alveolar injury, a hallmark of ARDS.

Cytokine Elevation in Severe COVID-19 From Longitudinal Proteomics Analysis: Comparison With Sepsis

Introduction

Coronavirus disease 2019 (COVID-19) is a new viral disease. Uncontrolled inflammation called “cytokine storm” is reported to contribute to disease pathogenesis as well as sepsis. We aimed to identify cytokines related to the pathogenesis of COVID-19 through a proteomics analysis of 1463 plasma proteins, validate these cytokines, and compare them with sepsis.

Materials and Methods

In a derivation cohort of 306 patients with COVID-19, 1463 unique plasma proteins were measured on days 1, 4, and 8. Cytokines associated with disease severity and prognosis were derived. In a validation cohort of 62 COVID-19 patients and 38 sepsis patients treated in the intensive care unit [ICU], these derived cytokines were measured on days 1 (day of ICU admission), 2-3, and 6-8 (maximum: 3 time points/patient). Derived cytokines were compared with healthy controls and between COVID-19 and sepsis patients, and the associations with prognosis were evaluated. The time to wean off mechanical ventilation (MV) was evaluated only for COVID-19.

Results

IL-6, amphiregulin, and growth differentiation factor (GDF)-15 were associated with disease severity and prognosis in the derivation cohort. In the validation cohort, IL-6 and GDF-15 were elevated in COVID-19 and sepsis on day 1, and the levels of these cytokines were higher in sepsis than in COVID-19. IL-6 and GDF-15 were associated with prognosis in sepsis. Cox proportional hazards model with time as a dependent covariate showed a significant relationship between plasma GDF-15 level and time to wean off MV (hazard ratio, 0.549 [95% confidence level, 0.382–0.789]). The GDF-15 level at ICU admission predicted late recovery.

Conclusion

GDF-15 and IL-6 derived from proteomics analysis were related with disease severity of COVID-19. Their values were higher in sepsis than in COVID-19 and were associated with prognosis in sepsis. In COVID-19 patients treated in the ICU, GDF-15 was associated with the time to wean off MV and better predicted late recovery.

Potential Immune Indicators for Predicting the Prognosis of COVID-19 and Trauma: Similarities and Disparities

Although cellular and molecular mediators of the immune system have the potential to be prognostic indicators of disease outcomes, temporal interference between diseases might affect the immune mediators, and make them difficult to predict disease complications. Today one of the most important challenges is predicting the prognosis of COVID-19 in the context of other inflammatory diseases such as traumatic injuries. Many diseases with inflammatory properties are usually polyphasic and the kinetics of inflammatory mediators in various inflammatory diseases might be different. To find the most appropriate evaluation time of immune mediators to accurately predict COVID-19 prognosis in the trauma environment, researchers must investigate and compare cellular and molecular alterations based on their kinetics after the start of COVID-19 symptoms and traumatic injuries. The current review aimed to investigate the similarities and differences of common inflammatory mediators (C-reactive protein, procalcitonin, ferritin, and serum amyloid A), cytokine/chemokine levels (IFNs, IL-1, IL-6, TNF-α, IL-10, and IL-4), and immune cell subtypes (neutrophil, monocyte, Th1, Th2, Th17, Treg and CTL) based on the kinetics between patients with COVID-19 and trauma. The mediators may help us to accurately predict the severity of COVID-19 complications and follow up subsequent clinical interventions. These findings could potentially help in a better understanding of COVID-19 and trauma pathogenesis.

Longitudinal Cytokine Profile in Patients With Mild to Critical COVID-19

The cytokine release syndrome has been proposed as the driver of inflammation in coronavirus disease 2019 (COVID-19). However, studies on longitudinal cytokine profiles in patients across the whole severity spectrum of COVID-19 are lacking. In this prospective observational study on adult COVID-19 patients admitted to two Hong Kong public hospitals, cytokine profiling was performed on blood samples taken during early phase (within 7 days of symptom onset) and late phase (8 to 12 days of symptom onset). The primary objective was to evaluate the difference in early and late cytokine profiles among patient groups with different disease severity. The secondary objective was to assess the associations between cytokines and clinical endpoints in critically ill patients. A total of 40 adult patients (mild = 8, moderate = 15, severe/critical = 17) hospitalized with COVID-19 were included in this study. We found 22 cytokines which were correlated with disease severity, as proinflammatory Th1-related cytokines (interleukin (IL)-18, interferon-induced protein-10 (IP-10), monokine-induced by gamma interferon (MIG), and IL-10) and ARDS-associated cytokines (IL-6, monocyte chemoattractant protein-1 (MCP-1), interleukin-1 receptor antagonist (IL-1RA), and IL-8) were progressively elevated with increasing disease severity. Furthermore, 11 cytokines were consistently different in both early and late phases, including seven (growth-regulated oncogene-alpha (GRO-α), IL-1RA, IL-6, IL-8, IL-10, IP-10, and MIG) that increased and four (FGF-2, IL-5, macrophage-derived chemokine (MDC), and MIP-1α) that decreased from mild to severe/critical patients. IL-8, followed by IP-10 and MDC were the best performing early biomarkers to predict disease severity. Among critically ill patients, MCP-1 predicted the duration of mechanical ventilation, highest norepinephrine dose administered, and length of intensive care stay.

Vandetanib Reduces Inflammatory Cytokines and Ameliorates COVID-19 in Infected Mice

The portfolio of SARS-CoV-2 small molecule drugs is currently limited to a handful that are either approved (remdesivir), emergency approved (dexamethasone, baricitinib) or in advanced clinical trials. We have tested 45 FDA-approved kinase inhibitors in vitro against murine hepatitis virus (MHV) as a model of SARS-CoV-2 replication and identified 12 showing inhibition in the delayed brain tumor (DBT) cell line. Vandetanib, which targets the vascular endothelial growth factor receptor (VEGFR), the epidermal growth factor receptor (EGFR), and the RET-tyrosine kinase showed the most promising results on inhibition versus toxic effect on SARS-CoV-2-infected Caco-2 and A549-hACE2 cells (IC50 0.79 μM) while also showing a reduction of > 3 log TCID50/mL for HCoV-229E. The in vivo efficacy of vandetanib was assessed in a mouse model of SARS-CoV-2 infection and statistically significantly reduced the levels of IL-6, IL-10, TNF-α, and mitigated inflammatory cell infiltrates in the lungs of infected animals but did not reduce viral load. Vandetanib rescued the decreased IFN-1β caused by SARS-CoV-2 infection in mice to levels similar to that in uninfected animals. Our results indicate that the FDA-approved vandetanib is a potential therapeutic candidate for COVID-19 positioned for follow up in clinical trials either alone or in combination with other drugs to address the cytokine storm associated with this viral infection.

Hemophagocytosis, hyper-inflammatory responses, and multiple organ damages in COVID-19-associated hyperferritinemia

Hyperferritinemia comes to light frequently in general practice. However, the characteristics of COVID-19-associated hyperferritinemia and the relationship with the prognosis were not well described. The retrospective study included 268 documented COVID-19 patients. They were divided into the hyperferritinemia group (≥ 500 µg/L) and the non-hyperferritinemia group (< 500 µg/L). The prevalence of fever and thrombocytopenia and the proportion of patients with mechanical ventilator support and in-hospital death were much higher in the hyperferritinemia group (P < 0.001). The hyperferritinemia patients showed higher median IL-6, D-dimer, and hsCRP (P < 0.001) and lowered FIB level (P = 0.036). The hyperferritinemia group had a higher proportion of patients with AKI, ARDS, and CSAC (P < 0.001). According to the multivariate analysis, age, chronic pulmonary disease, and hyperferritinemia were found to be significant independent predictors for in-hospital mortality [HR 1.041 (95% CI 1.015–1.068), P = 0.002; HR 0.427 (95% CI 0.206–0.882), P = 0.022; HR 6.176 (95% CI 2.447–15.587), P < 0.001, respectively]. The AUROC curve was 0.88, with a cut-off value of ≥ 971 µg/L. COVID-19 patients with hyperferritinemia had a high proportion of organ dysfunction, were more likely to show hyper-inflammation, progressed to hemophagocytic lymphohistiocytosis, and indicated a higher proportion of death.

The Good and Bad of Nrf2: An Update in Cancer and New Perspectives in COVID-19

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a well-known transcription factor best recognised as one of the main regulators of the oxidative stress response. Beyond playing a crucial role in cell defence by transactivating cytoprotective genes encoding antioxidant and detoxifying enzymes, Nrf2 is also implicated in a wide network regulating anti-inflammatory response and metabolic reprogramming. Such a broad spectrum of actions renders the factor a key regulator of cell fate and a strategic player in the control of cell transformation and response to viral infections. The Nrf2 protective roles in normal cells account for its anti-tumour and anti-viral functions. However, Nrf2 overstimulation often occurs in tumour cells and a complex correlation of Nrf2 with cancer initiation and progression has been widely described. Therefore, if on one hand, Nrf2 has a dual role in cancer, on the other hand, the factor seems to display a univocal function in preventing inflammation and cytokine storm that occur under viral infections, specifically in coronavirus disease 19 (COVID-19). In such a variegate context, the present review aims to dissect the roles of Nrf2 in both cancer and COVID-19, two widespread diseases that represent a cause of major concern today. In particular, the review describes the molecular aspects of Nrf2 signalling in both pathological situations and the most recent findings about the advantages of Nrf2 inhibition or activation as possible strategies for cancer and COVID-19 treatment respectively.