Persistent elevation of inflammatory cytokines predicts a poor outcome in ARDS. Plasma IL-1 beta and IL-6 levels are consistent and efficient predictors of outcome over time

Future Directions in Therapies for Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is caused by a complex interplay among hyperinflammation, endothelial dysfunction, and alveolar epithelial injury. Targeted treatments toward the underlying pathways have been unsuccessful in unselected patient populations. The first reliable biological subphenotypes reflective of these biological disease states have been identified in the past decade. Subphenotype targeted intervention studies are needed to advance the pharmacologic treatment of ARDS.

Sodium propionate ameliorates lipopolysaccharide-induced acute respiratory distress syndrome in rats via the PI3K/AKT/mTOR signaling pathway

Acute respiratory distress syndrome (ARDS) is a severe lung disease characterized by significant hypoxemia, which impairs the oxygen supply necessary for optimal lung function. This study aimed to investigate the effects of sodium propionate (SP), the primary end product of intestinal flora fermentation of dietary fiber, on lipopolysaccharide (LPS)-induced ARDS in rats. The rats were treated with SP, after which the lung wet/dry ratio, arterial partial oxygen pressure (PaO2), levels of pro- and anti-inflammatory cytokines, tight junction proteins ZO-1 and Occludin, as well as LC3 and phosphorylated PI3K (p-PI3K)/p-AKT/p-mTOR protein levels, were measured. Additionally, histopathological analysis was conducted. The results indicated that SP effectively alleviated arterial hypoxemia in rats and mitigated the pathological damage to both intestinal and lung tissues caused by LPS. Notably, SP significantly reduced the levels of inflammatory factors TNF-α and IL-6 in the blood and bronchoalveolar lavage fluid (BALF) of ARDS rats, while increasing the concentration of the anti-inflammatory factor IL-10. Furthermore, SP inhibited the activation of the PI3K/AKT/mTOR signaling pathway and enhanced the LC3II/LC3I ratio in lung tissue. Therefore, SP may improve LPS-induced ARDS in rats by inhibiting the activation of the PI3K/AKT/mTOR signaling pathway, promoting autophagy, decreasing the production and release of inflammatory markers, and reducing alveolar epithelial damage.

GSK3179106 ameliorates lipopolysaccharide-induced inflammation and acute lung injury by targeting P38 MAPK

Acute lung injury (ALI) is a serious acute respiratory disease that can cause alveolar-capillary barrier disruption and pulmonary edema, respiratory failure and multiple organ dysfunction syndrome. However, there is no effective drugs in clinic until now. GSK3179106 has been reported can alleviate intestinal stress syndrome, but the protective effect of GSK3179106 on ALI has not been elucidated. The present study will evaluate the pharmacological activity of GSK3179106 on lipopolysaccharide (LPS)-induced inflammation and lung injury and clarify its underlying mechanism. We found that GSK3179106 significantly attenuated LPS-induced lung injury in vivo, accompanied by inhibited infiltration of inflammatory cells and reduced expression of inflammatory cytokines. Meanwhile, GSK3179106 dose-dependently reduced the LPS-induced IL-6 expression both in protein and gene levels in macrophages. Mechanistically, GSK3179106 could inhibited the phosphorylation of P38 MAPK induced by LPS. Importantly, results showed that there is a direct combination between GSK3179106 and P38 MAPK. Together, our findings not only clarified the anti-inflammatory activity of GSK3179106 but also discovered its new clinical indications. Therefore, compound GSK3179106 may be a potential candidate for the treatment of acute inflammatory diseases.

Dexamethasone in COVID-19 treatment: Analyzing monotherapy and combination therapy approaches

The COVID-19 pandemic has prompted the exploration of effective treatment options, with dexamethasone emerging as a key corticosteroid for severe cases. This review evaluates the efficacy and safety of dexamethasone, highlighting its ability to reduce mortality rates, alleviate acute respiratory distress syndrome (ARDS), and mitigate hyperinflammation. While dexamethasone shows therapeutic promise, potential adverse effects-including cardiovascular issues, neuropsychiatric complications, lung infections, and liver damage-necessitate careful monitoring and individualized treatment strategies. The review also addresses the debate over using dexamethasone alone versus in combination with other therapies targeting SARS-CoV-2, examining potential synergistic effects and drug resistance. In summary, dexamethasone is a valuable treatment option for COVID-19 but its risks highlight the need for tailored surveillance approaches. Further research is essential to establish clear guidelines for optimizing treatment and improving patient outcomes.

Process-Specific Blood Biomarkers and Outcomes in COVID-19 Versus Non-COVID-19 ARDS (APEL-COVID Study): A Prospective, Observational Cohort Study

Background: Severe acute respiratory syndrome (SARS) and acute respiratory distress syndrome (ARDS) are often considered separate clinico-radiological entities. Whether these conditions also present a single process-specific systemic biomolecular phenotype and how this relates to patient outcomes remains unknown. A prospective cohort study was conducted, including adult patients admitted to the ICU and general floors for COVID-19-related (COVID+) or non-COVID-19-related (COVID-) acute respiratory failure during the main phase of the pandemic. The primary objective was to study blood biomarkers and outcomes among different groups and severity subsets. Results: A total of 132 patients were included, as follows: 67 COVID+, 54 COVID- (with 11 matched control subjects for biomarker reference), and 58 of these patients allowed for further pre- and post-analysis. The baseline apelin (APL) levels were higher in COVID+ patients (p < 0.0001 vs. COVID- patients) and in SARS COVID+ patients (p ≤ 0.02 vs. ARDS), while the IL-6 levels were higher in ARDS COVID- patients (p ≤ 0.0001 vs. SARS). Multivariable logistic regression analyses with cohort biomarkers and outcome parameters revealed the following: (i) log-transformed neprilysin (NEP) activity was significantly higher in COVID+ patients (1.11 [95% CI: 0.4-1.9] vs. 0.37 [95% CI: 0.1-0.8], fold change (FC): 1.43 [95% CI: 1.04-1.97], p = 0.029) and in SARS patients (FC: 1.65 [95% CI: 1.05-2.6], p = 0.032 vs. non-SARS COVID+ patients, and 1.73 [95% CI: 1.19-2.5], p = 0.005 vs. ARDS COVID- patients) and (ii) higher lysyl oxidase (LOX) activity and APL levels were respectively associated with death and a shorter length of hospital stay in SARS COVID+ patients (Odds Ratios (OR): 1.01 [1.00-1.02], p = 0.05, and OR: -0.007 [-0.013-0.0001], p = 0.048). Conclusion: Process-specific blood biomarkers exhibited distinct profiles between COVID+ and COVID- patients, and across stages of severity. NEP and LOX activities, as well as APL levels, are particularly linked to COVID+ patients and their outcomes (ClinicalTrials.gov Identifier: NCT04632732).

Identifying risk factors for acute respiratory distress syndrome in critically ill patients: a retrospective study

Background

Acute respiratory distress syndrome (ARDS) is a life-threatening condition that can develop in critically ill patients. Early identification of risk factors associated with ARDS development is essential for timely intervention and improved patient outcomes. This study aimed to investigate the potential predictors of ARDS in critically ill patients admitted to the intensive care unit (ICU).

Methods

We conducted a retrospective study involving 502 critically ill patients admitted to the ICUs of three hospitals. Demographic and clinical data, including laboratory test results, were collected during their ICU stay. Multivariable logistic regression analysis was performed to identify independent risk factors associated with the development of ARDS.

Results

Among the 502 critically ill patients, 104 (20.7%) patients developed ARDS during their ICU stay, with a median time to development of 5.2 days. Multivariable logistic regression analysis revealed that age (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.01-1.13; P = 0.002), C-reactive protein (CRP) levels (OR, 1.11; 95% CI, 1.05-1.17; P = 0.013), T lymphocyte count (OR, 0.82; 95% CI, 0.69-0.93; P = 0.011), and interleukin-6 (IL-6) levels (OR, 1.17; 95% CI, 1.08-1.23; P = 0.003) were independently associated with the development of ARDS in critically ill patients.

Conclusions

Our study identified age, CRP, T lymphocyte count, and IL-6 as independent predictors of ARDS in critically ill patients admitted to the ICU. These findings highlight the importance of monitoring these parameters in critically ill patients to identify those at high risk of developing ARDS. Early recognition and intervention based on these risk factors may improve patient outcomes in the ICU setting. Further prospective studies are warranted to validate these results and develop a reliable predictive model for ARDS in critically ill patients.

Prophylactic use of standardized extract of propolis of Apis mellifera (EPP-AF®) reduces lung inflammation and improves survival in experimental lethal sepsis

ETHNOPHARMACOLOGICAL RELEVANCE

Sepsis poses one of the biggest public health problems, necessitating the search for new therapeutic alternatives. For centuries, propolis has been widely used in folk medicine to treat various inflammatory and infectious diseases. Given its extensive use, it has excellent potential as an adjuvant treatment for patients with sepsis.

OBJECTIVE

This study evaluated prophylactic treatment with standardized propolis extract (EPP-AF®) and followed the prognosis of sepsis induced by ligation and cecal ligation and puncture (CLP).

METHODS

Initially, for survival assessment, Swiss mice were separated into five groups: Sham (false operated), control (PBS), ATB (received antibiotic, 8 mg/kg), P10 (received EPP-AF®, 10 mg/kg), and P100 (received EPP-AF®, 100 mg/kg). The animals received PBS, antibiotic, or EPP-AF® by the subcutaneous route 6 h before the CLP procedure. Animal survival was assessed every 12 h for five days when all of them were euthanized.

RESULTS

We show that the treatment with EPP-AF® significantly increased the life expectancy of animals with sepsis compared to the control group. Interestingly, prophylactic treatment with EPP-AF® showed no effect on the number of colony-forming units in the peritoneum, blood, or lung. However, there was a decrease in cellular influx in the peritoneum. This alteration was unrelated to the number of bone marrow cells or the differential counting of peripheral blood cells. The coagulogram remained unchanged, including the number of platelets and prothrombin time-activated partial thromboplastin time. However, the inflammatory infiltrate and bleeding in the lung tissue were lower in the animals that received EPP-AF®.

CONCLUSION

Thus, it was possible to conclude that prophylactic treatment with EPP-AF® preserved the lung parenchyma, resulting in an increased lifespan of mice with sepsis. It can be a helpful adjuvant in prophylactic treatment with antibiotics in presurgical conditions.

Predictors of the presence of radiological abnormalities 6 months after severe COVID-19 pneumonia

BACKGROUND

SARS-CoV-2 pneumonia can cause significant long-term radiological changes, even resembling pulmonary fibrosis. However, the risk factors for these long-term effects are unknown. This study aims to assess radiological abnormalities and their possible risk factors six months after hospital discharge due to COVID-19 pneumonia.

MATERIAL AND METHODS

This cross-sectional study in a tertiary hospital included adults admitted for COVID-19 pneumonia from March 2020 to February 2021, who underwent high-resolution computed tomography (HRCT) scans of the chest six months after hospital discharge. The primary outcome was radiological abnormalities on HRCT, while the main explanatory variables were drawn from the patient's medical history along with the disease course, analytical indicators, and the treatment received during admission.

RESULTS

The 189 included patients had a mean age of 61.5 years; 70.9% were male, and hypertension was the main comorbidity (45%). About two-thirds (67.2%) presented acute respiratory distress syndrome (ARDS). Most (97.9%) received systemic corticosteroid therapy, and 81% presented pathological findings on HRCT, most commonly ground glass (63.5%), followed by bronchial dilatation (36%) and subpleural bands (25.4%). The multivariable analysis showed that age was the main risk factor, associated with most radiological changes. Other factors were the duration of corticosteroid therapy for ground glass (adjusted odds ratio [aOR] 1.020) as well as a longer stay in the intensive care unit (ICU) (aOR 1.290) and high levels of IL-6 for bronchial dilation (aOR 1.002).

CONCLUSION

Radiological involvement of the lungs six months after COVID-19 pneumonia is frequent, especially ground glass. Elderly patients with prolonged ICU admission and a significant inflammatory response measured by IL-6 are more likely to present worse radiological evolution and are candidates for radiological follow-up after COVID-19 pneumonia.

Impact of interleukin 6 levels on acute lung injury risk and disease severity in critically ill sepsis patients

BACKGROUND

Sepsis is a life-threatening condition characterized by a dysregulation of the host response to infection that can lead to acute lung injury (ALI) and multiple organ dysfunction syndrome (MODS). Interleukin 6 (IL-6) is a pro-inflammatory cytokine that plays a crucial role in the pathogenesis of sepsis and its complications.

AIM

To investigate the relationship among plasma IL-6 levels, risk of ALI, and disease severity in critically ill patients with sepsis.

METHODS

This prospective and observational study was conducted in the intensive care unit of a tertiary care hospital between January 2021 and December 2022. A total of 83 septic patients were enrolled. Plasma IL-6 levels were measured upon admission using an enzyme-linked immunosorbent assay. The development of ALI and MODS was monitored during hospitalization. Disease severity was evaluated by Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores.

RESULTS

Among the 83 patients with sepsis, 38 (45.8%) developed ALI and 29 (34.9%) developed MODS. Plasma IL-6 levels were significantly higher in patients who developed ALI than in those without ALI (median: 125.6 pg/mL vs 48.3 pg/mL; P < 0.001). Similarly, patients with MODS had higher IL-6 levels than those without MODS (median: 142.9 pg/mL vs 58.7 pg/mL; P < 0.001). Plasma IL-6 levels were strongly and positively correlated with APACHE II (r = 0.72; P < 0.001) and SOFA scores (r = 0.68; P < 0.001).

CONCLUSION

Elevated plasma IL-6 levels in critically ill patients with sepsis were associated with an increased risk of ALI and MODS. Higher IL-6 levels were correlated with greater disease severity, as reflected by higher APACHE II and SOFA scores. These findings suggest that IL-6 may serve as a biomarker for predicting the development of ALI and disease severity in patients with sepsis.

Role of biomarkers and molecular signaling pathways in acute lung injury

BACKGROUND

Acute lung injury (ALI) is caused by bacterial, fungal, and viral infections. When pathogens invade the lungs, the immune system responds by producing cytokines, chemokines, and interferons to promote the infiltration of phagocytic cells, which are essential for pathogen clearance. Their excess production causes an overactive immune response and a pathological hyper-inflammatory state, which leads to ALI. Until now, there is no particular pharmaceutical treatment available for ALI despite known inflammatory mediators like neutrophil extracellular traps (NETs) and reactive oxygen species (ROS).

OBJECTIVES

Therefore, the primary objective of this review is to provide the clear overview on the mechanisms controlling NETs, ROS formation, and other relevant processes during the pathogenesis of ALI. In addition, we have discussed the significance of epithelial and endothelial damage indicators and several molecular signaling pathways associated with ALI.

METHODS

The literature review was done from Web of Science, Scopus, PubMed, and Google Scholar for ALI, NETs, ROS, inflammation, biomarkers, Toll- and nucleotide-binding oligomerization domain (NOD)-like receptors, alveolar damage, pro-inflammatory cytokines, and epithelial/endothelial damage alone or in combination.

RESULTS

This review summarized the main clinical signs of ALI, including the regulation and distinct function of epithelial and endothelial biomarkers, NETs, ROS, and pattern recognition receptors (PRRs).

CONCLUSION

However, no particular drugs including vaccine for ALI has been established. Furthermore, there is a lack of validated diagnostic tools and a poor predictive rationality of current therapeutic biomarkers. Hence, extensive and precise research is required to speed up the process of drug testing and development by the application of artificial intelligence technologies, structure-based drug design, in-silico approaches, and drug repurposing.

The effect of thyme essential oil and endothelial progenitor stem cells on lipopolysaccharide-induced sepsis in C57BL/6 mice

Sepsis is a potentially fatal syndrome related to severe systemic inflammation developed by infection. Despite different antimicrobial therapies, morbidity and mortality rates remain high. Herbs along with cell therapy have been introduced as a promising option to improve the symptoms of sepsis. The present study aimed to evaluate the therapeutic effect of simultaneous administration of thyme essential oil (TEO) and endothelial progenitor stem cells (EPCs) on lipopolysaccharide (LPS)-induced sepsis in C57BL/6 mice. Sepsis was induced in C57Bl/6J mice by intraperitoneal injection of LPS, followed 2 h later by an intravenous injection of EPCs or oral administration of TEO or simultaneous administration of TEO and EPCs. After 10 days, the complete blood cell, renal and liver factors, serum levels of inflammatory cytokines, and angiogenic factors were measured. Simultaneous treatment with EPCs and TEO significantly increased the survival of mice with sepsis and modulated the inflammatory response by reducing the serum levels of pro-inflammatory cytokines. Moreover, this treatment significantly reduced the level of white blood cells and neutrophils and increased the number of red blood cells, the percentage of hematocrit, and hemoglobin. The combination of TEO with EPCs decreased organ injuries and was assessed by lower levels of the liver enzymes alanine aminotransferase and aspartate aminotransferase compared to the sepsis group. Administration of EPCs and TEO also significantly improved angiogenic factors, lung function, and toll-like receptor 4 expression. EPCs in combination with TEO increase survival in the LPS-induced sepsis mice model by acting on several targets. Thus, the combination of TEO with EPCs can be a feasible approach for the future clinical treatment and control of sepsis.

A therapy for suppressing canonical and noncanonical SARS-CoV-2 viral entry and an intrinsic intrapulmonary inflammatory response

The prevalence of "long COVID" is just one of the conundrums highlighting how little we know about the lung's response to viral infection, particularly to syndromecoronavirus-2 (SARS-CoV-2), for which the lung is the point of entry. We used an in vitro human lung system to enable a prospective, unbiased, sequential single-cell level analysis of pulmonary cell responses to infection by multiple SARS-CoV-2 strains. Starting with human induced pluripotent stem cells and emulating lung organogenesis, we generated and infected three-dimensional, multi-cell-type-containing lung organoids (LOs) and gained several unexpected insights. First, SARS-CoV-2 tropism is much broader than previously believed: Many lung cell types are infectable, if not through a canonical receptor-mediated route (e.g., via Angiotensin-converting encyme 2(ACE2)) then via a noncanonical "backdoor" route (via macropinocytosis, a form of endocytosis). Food and Drug Administration (FDA)-approved endocytosis blockers can abrogate such entry, suggesting adjunctive therapies. Regardless of the route of entry, the virus triggers a lung-autonomous, pulmonary epithelial cell-intrinsic, innate immune response involving interferons and cytokine/chemokine production in the absence of hematopoietic derivatives. The virus can spread rapidly throughout human LOs resulting in mitochondrial apoptosis mediated by the prosurvival protein Bcl-xL. This host cytopathic response to the virus may help explain persistent inflammatory signatures in a dysfunctional pulmonary environment of long COVID. The host response to the virus is, in significant part, dependent on pulmonary Surfactant Protein-B, which plays an unanticipated role in signal transduction, viral resistance, dampening of systemic inflammatory cytokine production, and minimizing apoptosis. Exogenous surfactant, in fact, can be broadly therapeutic.

Restoring discarded porcine lungs by ex vivo removal of neutrophil extracellular traps

BACKGROUND

By causing inflammation and tissue damage, neutrophil extracellular traps (NETs) constitute an underlying mechanism of aspiration-induced lung injury, a major factor of the low utilization of donor lungs in lung transplantation (LTx).

METHODS

To determine whether NET removal during ex vivo lung perfusion (EVLP) can restore lung function and morphology in aspiration-damaged lungs, gastric aspiration lung injury was induced in 12 pigs. After confirmation of acute respiratory distress syndrome, the lungs were explanted and assigned to NET removal connected to EVLP (treated) (n = 6) or EVLP only (nontreated) (n = 6). Hemodynamic measurements were taken, and blood and tissue samples were collected to assess lung function, morphology, levels of cell-free DNA, extracellular histones, and nucleosomes as markers of NETs, as well as cytokine levels.

RESULTS

After EVLP and NET removal in porcine lungs, PaO2/FiO2 ratios increased significantly compared to those undergoing EVLP alone (p = 0.0411). Treated lungs had lower cell-free DNA (p = 0.0260) and lower levels of extracellular histones in EVLP perfusate (p= 0.0260) than nontreated lungs. According to histopathology, treated lungs showed less immune cell infiltration and less edema compared with nontreated lungs, which was reflected in decreased levels of proinflammatory cytokines in EVLP perfusate and bronchoalveolar lavage fluid.

CONCLUSIONS

To conclude, removing NETs during EVLP improved lung function and morphology in aspiration-damaged donor lungs. The ability to remove NETs during EVLP could represent a new therapeutic approach for LTx and potentially expand the donor pool for transplantation.

Interleukin-1 Receptor Antagonist Gene (IL1RN) Variants Modulate the Cytokine Release Syndrome and Mortality of COVID-19

BACKGROUND

We examined effects of single-nucleotide variants (SNVs) of IL1RN, the gene encoding the anti-inflammatory interleukin 1 receptor antagonist (IL-1Ra), on the cytokine release syndrome (CRS) and mortality in patients with acute severe respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

METHODS

IL1RN CTA haplotypes formed from 3 SNVs (rs419598, rs315952, rs9005) and the individual SNVs were assessed for association with laboratory markers of inflammation and mortality. We studied 2589 patients hospitalized with SARS-CoV-2 between March 2020 and March 2021.

RESULTS

Mortality was 15.3% and lower in women than men (13.1% vs 17.3%, P = .0003). Carriers of the CTA-1/2 IL1RN haplotypes exhibited decreased inflammatory markers and increased plasma IL-1Ra. Evaluation of the individual SNVs of the IL1RN, carriers of the rs419598 C/C SNV exhibited significantly reduced inflammatory biomarker levels and numerically lower mortality compared to the C/T-T/T genotype (10.0% vs 17.8%, P = .052) in men, with the most pronounced association observed in male patients ≤74 years old, whose mortality was reduced by 80% (3.1% vs 14.0%, P = .030).

CONCLUSIONS

The IL1RN haplotype CTA and C/C variant of rs419598 are associated with attenuation of the CRS and decreased mortality in men with acute SARS-CoV-2 infection. The data suggest that the IL1RN pathway modulates the severity of coronavirus disease 2019 (COVID-19) via endogenous anti-inflammatory mechanisms.

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.

The relationship between red cell distribution width, serum calcium ratio, and in-hospital mortality among patients with acute respiratory failure: A retrospective cohort study of the MIMIC-IV database

To investigate the impact of RDW/CA (the ratio of red cell distribution width to calcium) on in-hospital mortality in patients with acute respiratory failure (ARF). This retrospective cohort study analyzed the data of 6981 ARF patients from the Medical Information Mart for Intensive Care (MIMIC-IV) database 2.0. Critically ill participants between 2008 and 2019 at the Beth Israel Deaconess Medical Center in Boston. The primary outcome of interest was in-hospital mortality. A Cox proportional hazards regression model was used to determine whether the RDW/CA ratio independently correlated with in-hospital mortality. The Kaplan-Meier method was used to plot the survival curves of the RDW/CA. Subgroup analyses were performed to measure the mortality across various subgroups. After adjusting for potential covariates, we found that a higher RDW/CA was associated with an increased risk of in-hospital mortality (HR = 1.17, 95% CI: 1.01-1.35, P = .0365) in ARF patients. A nonlinear relationship was observed between RDW/CA and in-hospital mortality, with an inflection point of 1.97. When RDW/CA ≥ 1.97 was positively correlated with in-hospital mortality in patients with ARF (HR = 1.554, 95% CI: 1.183-2.042, P = .0015). The Kaplan-Meier curve indicated the higher survival rates for RDW/CA < 1.97 and the lower for RDW/CA ≥ 1.97 after adjustment for age, gender, body mass index, and ethnicity. RDW/CA is an independent predictor of in-hospital mortality in patients with ARF. Furthermore, a nonlinear relationship was observed between RDW/CA and in-hospital mortality in patients with ARF.

Clinical features that predict the mortality risk in older patients with Omicron pneumonia: the MLWAP score

In December 2022, the Chinese suffered widespread Omicron of SARS-CoV-2 with variable symptom severity and outcome. We wanted to develop a scoring model to predict the mortality risk of older Omicron pneumonia patients by analyzing admission data. We enrolled 227 Omicron pneumonia patients aged 60 years and older, admitted to our hospital from December 15, 2022, to January 16, 2023, and divided them randomly into a 70% training set and a 30% test set. The former were used to identify predictors and develop a model, the latter to verify the model, using the area under the receiver operating characteristic curve (AUC), the Hosmer-Lemeshow goodness-of-fit test, a calibration curve to test its performance and comparing it to the existing scores. The MLWAP score was calculated based on a multivariate logistic regression model to predict mortality with a weighted score that included immunosuppression, lactate ≥ 2.4, white blood cell count ≥ 6.70 × 109/L, age ≥ 77 years, and PaO2/FiO2 ≤ 211. The AUC for the model in the training and test sets was 0.852 (95% CI, 0.792-0.912) and 0.875 (95% CI, 0.789-0.961), respectively. The calibration curves showed a good fit. We grouped the risk scores into low (score 0-7 points), medium (8-10 points), and high (11-13 points). This model had a sensitivity of 0.849, specificity of 0.714, and better predictive ability than the CURB-65 and PSI scores (AUROC = 0.859 vs. 0.788 vs. 0.801, respectively). The MLWAP-mortality score may help clinicians to stratify hospitalized older Omicron pneumonia patients into relevant risk categories, rationally allocate medical resources, and reduce the mortality.

Function of KvLQT1 potassium channels in a mouse model of bleomycin-induced acute lung injury

Acute respiratory distress syndrome (ARDS) is characterized by an exacerbated inflammatory response, severe damage to the alveolar-capillary barrier and a secondary infiltration of protein-rich fluid into the airspaces, ultimately leading to respiratory failure. Resolution of ARDS depends on the ability of the alveolar epithelium to reabsorb lung fluid through active transepithelial ion transport, to control the inflammatory response, and to restore a cohesive and functional epithelium through effective repair processes. Interestingly, several lines of evidence have demonstrated the important role of potassium (K+) channels in the regulation of epithelial repair processes. Furthermore, these channels have previously been shown to be involved in sodium/fluid absorption across alveolar epithelial cells, and we have recently demonstrated the contribution of KvLQT1 channels to the resolution of thiourea-induced pulmonary edema in vivo. The aim of our study was to investigate the role of the KCNQ1 pore-forming subunit of KvLQT1 channels in the outcome of ARDS parameters in a model of acute lung injury (ALI). We used a molecular approach with KvLQT1-KO mice challenged with bleomycin, a well-established ALI model that mimics the key features of the exudative phase of ARDS on day 7. Our data showed that KvLQT1 deletion exacerbated the negative outcome of bleomycin on lung function (resistance, elastance and compliance). An alteration in the profile of infiltrating immune cells was also observed in KvLQT1-KO mice while histological analysis showed less interstitial and/or alveolar inflammatory response induced by bleomycin in KvLQT1-KO mice. Finally, a reduced repair rate of KvLQT1-KO alveolar cells after injury was observed. This work highlights the complex contribution of KvLQT1 in the development and resolution of ARDS parameters in a model of ALI.

Impact of post-COVID-19 lung damage on pulmonary function, exercise tolerance and quality of life in Indian subjects

After recovery from COVID-19, there is data to suggest potential long-term pulmonary sequelae and associated impairment of functional capacity. This cross-sectional study was designed to assess the impact on respiratory function in a cohort of Indian subjects. Subjects who had recovered from COVID-19 were recruited. Clinical symptoms, pulmonary function test results, 6-minute walk test (6MWT) results, St George's Respiratory questionnaire (SGRQ) and chest radiographs were obtained. Information on the COVID-19 illness during hospitalization, baseline laboratory biomarkers and the disease severity categories as outlined by WHO (asymptomatic, mild, moderate, severe and critical), were retrieved from the hospital records. The 'COVID pneumonia'(WHO category moderate, severe & critical) group was compared with the 'Mild COVID' (WHO category mild) group and likewise, the WHO category moderate and the WHO category severe/critical groups were compared. In 207 subjects, whose mean age was 48.7 years were assessed after an average of 63 days from onset of symptom, 35% had TLC< 80% (restrictive defect), 8.3% had FEV1/FVC<70% (obstructive defect) and 44.4% had diminished DLCO<80% (diffusing capacity). The 'COVID-19 pneumonia' group when compared to the 'mild COVID-19' group, had lower FVC% (77.85 VS 88.18; P = 0.001), TLC% (79.48 VS 87.91; P = 0.0002), DLCO% (75.30 VS 89.20; P<0.0001) and DLCO/VA% (105.6 VS 111.8; P = 0.032), decreased minimum oxygen saturation (94.89 VS 97.73; P<0.0001) and more subjects had a drop in saturation of ≥ 4% (21.69% VS 4.84%; P = 0.001) during the 6MWT, and a greater mean total SGRQ score (29.2 VS 11.0; P<0.0001). To our knowledge, this is the first such report on Indian subjects. We have shown that post-COVID-19 lung damage leads to significant impairment of lung function, quality of life and effort tolerance.

Temporal Association Between Vaping and Risk of Cardiac Events

OBJECTIVE

To describe our early observations with sudden cardiac arrest (SCA) and sudden death (SD) in patients using vape products.

PATIENTS AND METHODS

A retrospective analysis of Mayo Clinic's Windland Smith Rice Genetic Heart Rhythm Clinic and Sudden Death Genomics Laboratory was performed on all SCA survivors and decedents who presented between January 1, 2007, and December 31, 2021, to identify patients/decedents with a history of vaping. Data abstraction included patient demographics, clinical characteristics, and documented use of vape products.

RESULTS

Among 144 SCA survivors and 360 SD victims, there were six individuals (1%; 3 females) with unexplained SCA (n=4) or SD (n=2) that was temporally associated with vaping use with a mean age at sentinel event of 23±5 years. The SCA survivors include a 19-year-old male who was resuscitated from documented ventricular fibrillation 40 minutes after vaping and a 19-year-old male who was resuscitated from ventricular fibrillation a few hours post vaping. The first SD victim was a 19-year-old female with exercise-induced asthma who died in her sleep after vaping that evening. Autopsy results showed eosinophilic infiltrates in the lung tissue and death was attributed to bronchial asthma. The second vaping-associated death involved a 26-year-old male whose autopsy attributed the death to acute respiratory distress syndrome.

CONCLUSION

We have identified six young individuals with a history of vaping who experienced a near fatal episode or a tragic SD. Although larger cohort studies are needed to quantify the actual risk of SD, it seems prudent to sound an early warning about vaping's potential lethality.

Impact of IL-6 rs1800795 and IL-17A rs2275913 gene polymorphisms on the COVID-19 prognosis and susceptibility in a sample of Iranian patients

BACKGROUND

From asymptomatic to acute and life-threatening pulmonary infection, the clinical manifestations of COVID-19 are highly variable. Interleukin (IL)-6 and IL-17A are key drivers of hyper inflammation status in COVID-19, and their elevated levels are hallmarks of the infection progression. To explore whether prognosis and susceptibility to COVID-19 are linked to IL-6 rs1800795 and IL-17A rs2275913, these single-nucleotide polymorphisms (SNPs) were assessed in a sample of Iranian COVID-19 patients.

METHODS

This study enrolled two hundred and eighty COVID-19 patients (140 non-severe and 140 severe). Genotyping for IL-6 rs1800795 and IL-17A rs2275913 was performed using tetra primer-amplification refractory mutation system-polymerase chain reaction (tetra-ARMS-PCR). IL-6 and IL-17A circulating levels were measured using enzyme-linked immunosorbent assay (ELISA). Also, mortality predictors of COVID-19 were investigated.

RESULTS

The rs1800795 GG genotype (78/140 (55.7 %)) and G allele (205/280 (73.2 %)) were significantly associated with a positive risk of COVID-19 severe infection (OR = 2.19, 95 %CI: 1.35-3.54, P =.006 and OR = 1.79, 95 %CI: 1.25-2.56, P <.001, respectively). Also, rs1800795 GG genotype was significantly linked to disease mortality (OR = 1.95, 95 %CI: 1.06-3.61, P =.04). The rs2275913 GA genotype was protective against severe COVID-19 (OR = 0.5, 95 %CI: 0.31--0.80, P =.012). However, the present study did not reveal any significant link between rs2275913 genotypes with disease mortality. INR ≥ 1.2 (OR = 2.19, 95 %CI: 1.61-3.78, P =.007), D-dimer ≥ 565.5 ng/mL (OR = 3.12, 95 %CI: 1.27-5.68, P =.019), respiratory rate ≥ 29 (OR = 1.19, 95 %CI: 1.12-1.28, P =.001), IL-6 serum concentration ≥ 28.5 pg/mL (OR = 1.97, 95 %CI: 1.942-2.06, P =.013), and IL-6 rs1800795 GG genotype (OR = 1.95, 95 %CI: 1.06-3.61, P =.04) were predictive of COVID-19 mortality.

CONCLUSION

The rs1800795 GG genotype and G allele were associated with disease severity, and INR, D-dimer, respiratory rate, IL-6 serum concentration, and IL-6 rs1800795 GG genotype were predictive of COVID-19 mortality.

Interorgan communication networks in the kidney-lung axis

The homeostasis and health of an organism depend on the coordinated interaction of specialized organs, which is regulated by interorgan communication networks of circulating soluble molecules and neuronal connections. Many diseases that seemingly affect one primary organ are really multiorgan diseases, with substantial secondary remote organ complications that underlie a large part of their morbidity and mortality. Acute kidney injury (AKI) frequently occurs in critically ill patients with multiorgan failure and is associated with high mortality, particularly when it occurs together with respiratory failure. Inflammatory lung lesions in patients with kidney failure that could be distinguished from pulmonary oedema due to volume overload were first reported in the 1930s, but have been largely overlooked in clinical settings. A series of studies over the past two decades have elucidated acute and chronic kidney-lung and lung-kidney interorgan communication networks involving various circulating inflammatory cytokines and chemokines, metabolites, uraemic toxins, immune cells and neuro-immune pathways. Further investigations are warranted to understand these clinical entities of high morbidity and mortality, and to develop effective treatments.

LC-QToF chemical profiling of Euphorbia grantii Oliv. and its potential to inhibit LPS-induced lung inflammation in rats via the NF-κB, CY450P2E1, and P38 MAPK14 pathways

Acute lung injury (ALI) is a life-threatening syndrome that causes high morbidity and mortality worldwide. The aerial parts of Euphorbia grantii Oliv. were extracted with methanol to give a total methanolic extract (TME), which was further fractionated into dichloromethane (DCMF) and the remaining mother liquor (MLF) fractions. Biological guided anti-inflammatory assays in vitro revealed that the DCMF showed the highest activity (IC50 6.9 ± 0.2 μg/mL and 0.29 ± 0.01 μg/mL) compared to. celecoxib (IC50 of 88.0 ± 1 μg/mL and 0.30 ± 0.01 μg/mL) on COX-1 and COX-2, respectively. Additionally, anti-LOX activity was IC50 = 24.0 ± 2.5 μg/mL vs. zileuton with IC50 of 40.0 ± 0.5 μg/mL. LC-DAD-QToF analysis of TME and the active DCMF resulted in the tentative identification and characterization of 56 phytochemical compounds, where the diterpenes were the dominated metabolites. An LPS-induced inflammatory model of ALI (10 mg/kg i.p) was used to assess the anti-inflammatory potential of DCMF in vivo at dose of 200 mg/kg and 300 mg/kg compared to dexamethasone (5 mg/kg i.p). Our treatments significantly reduced the pro-inflammatory cytokines (TNF-α, IL-1, IL-6, and MPO), increased the activity of antioxidant enzymes (SOD, CAT, and GSH), decreased the activity of oxidative stress enzyme (MDA), and reduced the expression of inflammatory genes (p38.MAPK14 and CY450P2E1). The western blotting of NF-κB p65 in lung tissues was inhibited after orally administration of the DCMF. Histopathological study of the lung tissues, scoring, and immunohistochemistry of transforming growth factor-beta 1 (TGF-β1) were also assessed. In both dose regimens, DCMF of E. grantii prevented further lung damage and reduced the side effects of LPS on acute lung tissue injury.

Direct reinfusion of pericardial blood complications: A case of acute respiratory distress syndrome and disseminated intravascular coagulation

Background

Direct reinfusion of pericardial blood during cardiac surgery triggers a systemic inflammatory response. Although various inflammatory mediators have been identified as triggers, the role of damage-associated molecular patterns (DAMPs) remains poorly understood. Despite guidelines recommending against this practice owing to its harmful effects, it is sometimes used in emergencies.

Case Presentation

A 72-year-old man with atrial fibrillation and cerebral infarction developed cardiac tamponade during catheter ablation. He underwent pericardial drainage and direct blood reinfusion. He was transferred to our ICU, where he developed acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC). Despite aggressive management, the patient died 41 days after admission.

Conclusion

This case highlights severe adverse events following direct reinfusion of pericardial blood. These findings suggest a significant role for DAMPs in mediating these inflammatory responses. Direct reinfusion of pericardial drainage blood should be avoided during emergencies to prevent life-threatening complications.

A scoring model based on clinical factors to predict postoperative moderate to severe acute respiratory distress syndrome in Stanford type A aortic dissection

BACKGROUND

Postoperative acute respiratory distress syndrome (ARDS) after type A aortic dissection is common and has high mortality. However, it is not clear which patients are at high risk of ARDS and an early prediction model is deficient.

METHODS

From May 2015 to December 2017, 594 acute Stanford type A aortic dissection (ATAAD) patients who underwent aortic surgery in Anzhen Hospital were enrolled in our study. We compared the early survival of MS-ARDS within 24 h by Kaplan-Meier curves and log-rank tests. The data were divided into a training set and a test set at a ratio of 7:3. We established two prediction models and tested their efficiency.

RESULTS

The oxygenation index decreased significantly immediately and 24 h after TAAD surgery. A total of 363 patients (61.1%) suffered from moderate and severe hypoxemia within 4 h, and 243 patients (40.9%) suffered from MS-ARDS within 24 h after surgery. Patients with MS-ARDS had higher 30-day mortality than others (log-rank test: p-value <0.001). There were 30 variables associated with MS-ARDS after surgery. The XGboost model consisted of 30 variables. The logistic regression model (LRM) consisted of 11 variables. The mean accuracy of the XGBoost model was 70.7%, and that of the LRM was 80.0%. The AUCs of XGBoost and LRM were 0.764 and 0.797, respectively.

CONCLUSION

Postoperative MS-ARDS significantly increased early mortality after TAAD surgery. The LRM model has higher accuracy, and the XGBoost model has higher specificity.

Inflammatory subphenotypes in patients at risk of ARDS: evidence from the LIPS-A trial

PURPOSE

Latent class analysis (LCA) has identified hyper- and non-hyper-inflammatory subphenotypes in patients with acute respiratory distress syndrome (ARDS). It is unknown how early inflammatory subphenotypes can be identified in patients at risk of ARDS. We aimed to test for inflammatory subphenotypes upon presentation to the emergency department.

METHODS

LIPS-A was a trial of aspirin to prevent ARDS in at-risk patients presenting to the emergency department. In this secondary analysis, we performed LCA using clinical, blood test, and biomarker variables.

RESULTS

Among 376 (96.4%) patients from the LIPS-A trial, two classes were identified upon presentation to the emergency department (day 0): 72 (19.1%) patients demonstrated characteristics of a hyper-inflammatory and 304 (80.9%) of a non-hyper-inflammatory subphenotype. 15.3% of patients in the hyper- and 8.2% in the non-hyper-inflammatory class developed ARDS (p = 0.07). Patients in the hyper-inflammatory class had fewer ventilator-free days (median [interquartile range, IQR] 28[23-28] versus 28[27-28]; p = 0.010), longer intensive care unit (3[2-6] versus 0[0-3] days; p < 0.001) and hospital (9[6-18] versus 5[3-9] days; p < 0.001) length of stay, and higher 1-year mortality (34.7% versus 20%; p = 0.008). Subphenotypes were identified on day 1 and 4 in a subgroup with available data (n = 244). 77.9% of patients remained in their baseline class throughout day 4. Patients with a hyper-inflammatory subphenotype throughout the study period (n = 22) were at higher risk of ARDS (36.4% versus 10.4%; p = 0.003).

CONCLUSION

Hyper- and non-hyper-inflammatory subphenotypes may precede ARDS development, remain identifiable over time, and can be identified upon presentation to the emergency department. A hyper-inflammatory subphenotype predicts worse outcomes.

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

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

Adenosquamous carcinoma of the gallbladder simultaneously producing granulocyte-colony-stimulating factor and parathyroid hormone-related protein

We report a rare case of adenosquamous carcinoma of the gallbladder which simultaneously produces granulocyte-colony-stimulating factor (G-CSF) and parathyroid hormone-related protein (PTHrP), confirmed serologically and histologically. A 71-year-old man was examined for a gallbladder tumor with multiple lymph nodes and liver metastases. Histopathological evaluation by endoscopic ultrasound fine-needle aspiration revealed adenosquamous carcinoma of the gallbladder. Laboratory data showed markedly elevated white blood cell (WBC) count of 34,700 µL and corrected serum calcium level of 14.9 mg/dL. Serum G-CSF (191 pg/mL) and PTHrP (23.1 pmol/L) levels were high. Zoledronic acid and calcitonin were administered to treat hypercalcemia, which normalized serum calcium levels. Gemcitabine-cisplatin chemotherapy was started for cStage IVB gallbladder cancer. After chemotherapy initiation, WBCs showed a rapid downward trend; however, the patient suddenly developed acute respiratory distress syndrome; thus, chemotherapy was discontinued. Subsequently, WBC count increased again, and the patient's overall condition deteriorated. The patient died on day 27. Immunohistochemistry using autopsy specimens demonstrated patchy staining for G-CSF in the squamous cell carcinoma portion and diffuse and weak positive staining for PTHrP in the squamous cell carcinoma and poorly differentiated adenocarcinoma portions of the tumor, suggesting simultaneous G-CSF and PTHrP production by the tumor. This is the first report of a patient with gallbladder cancer with serological and histological evidence for G-CSF and PTHrP production.

Interesting effects of interleukins and immune cells on acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a medical condition characterized by widespread inflammation in the lungs with consequent proportional loss of gas exchange function. ARDS is linked with severe pulmonary or systemic infection. Several factors, including secretory cytokines, immune cells, and lung epithelial and endothelial cells, play a role in the development and progression of this disease. The present study is based on Pubmed database information (1987-2022) using the words "Acute respiratory distress syndrome", "Interleukin", "Cytokines" and "Immune cells". Cytokines and immune cells play an important role in this disease, with particular emphasis on the balance between pro-inflammatory and anti-inflammatory factors. Neutrophils are one of several important mediators of Inflammation, lung tissue destruction, and malfunction during ARDS. Some immune cells, such as macrophages and eosinophils, play a dual role in releasing inflammatory mediators, recruitment inflammatory cells and the progression of ARDS, or releasing anti-inflammatory mediators, clearing the lung of inflammatory cells, and helping to improve the disease. Different interleukins play a role in the development or inhibition of ARDS by helping to activate various signaling pathways, helping to secrete other inflammatory or anti-inflammatory interleukins, and playing a role in the production and balance between immune cells involved in ARDS. As a result, immune cells and, inflammatory cytokines, especially interleukins play an important role in the pathogenesis of this disease Therefore, understanding the relevant mechanisms will help in the proper diagnosis and treatment of this disease.

Liraglutide pretreatment attenuates sepsis-induced acute lung injury

There are no effective targeted therapies to treat acute respiratory distress syndrome (ARDS). Recently, the commonly used diabetes and obesity medications, glucagon-like peptide-1 (GLP-1) receptor agonists, have been found to have anti-inflammatory properties. We, therefore, hypothesized that liraglutide pretreatment would attenuate murine sepsis-induced acute lung injury (ALI). We used a two-hit model of ALI (sepsis+hyperoxia). Sepsis was induced by intraperitoneal injection of cecal slurry (CS; 2.4 mg/g) or 5% dextrose (control) followed by hyperoxia [HO; fraction of inspired oxygen ([Formula: see text]) = 0.95] or room air (control; [Formula: see text] = 0.21). Mice were pretreated twice daily with subcutaneous injections of liraglutide (0.1 mg/kg) or saline for 3 days before initiation of CS+HO. At 24-h post CS+HO, physiological dysfunction was measured by weight loss, severity of illness score, and survival. Animals were euthanized, and bronchoalveolar lavage (BAL) fluid, lung, and spleen tissues were collected. Bacterial burden was assessed in the lung and spleen. Lung inflammation was assessed by BAL inflammatory cell numbers, cytokine concentrations, lung tissue myeloperoxidase activity, and cytokine expression. Disruption of the alveolar-capillary barrier was measured by lung wet-to-dry weight ratios, BAL protein, and epithelial injury markers (receptor for advanced glycation end products and sulfated glycosaminoglycans). Histological evidence of lung injury was quantified using a five-point score with four parameters: inflammation, edema, septal thickening, and red blood cells (RBCs) in the alveolar space. Compared with saline treatment, liraglutide improved sepsis-induced physiological dysfunction and reduced lung inflammation, alveolar-capillary barrier disruption, and lung injury. GLP-1 receptor activation may hold promise as a novel treatment strategy for sepsis-induced ARDS. Additional studies are needed to better elucidate its mechanism of action.NEW & NOTEWORTHY In this study, pretreatment with liraglutide, a commonly used diabetes medication and glucagon-like peptide-1 (GLP-1) receptor agonist, attenuated sepsis-induced acute lung injury in a two-hit mouse model (sepsis + hyperoxia). Septic mice who received the drug were less sick, lived longer, and displayed reduced lung inflammation, edema, and injury. These therapeutic effects were not dependent on weight loss. GLP-1 receptor activation may hold promise as a new treatment strategy for sepsis-induced acute respiratory distress syndrome.

Circulatory HMGB1 is an early predictive and prognostic biomarker of ARDS and mortality in a swine model of polytrauma

Acute respiratory distress syndrome (ARDS) is a leading cause of morbidity and mortality in polytrauma patients. Pharmacological treatments of ARDS are lacking, and ARDS patients rely on supportive care. Accurate diagnosis of ARDS is vital for early intervention and improved outcomes but is presently delayed up to days. The use of biomarkers for early identification of ARDS development is a potential solution. Inflammatory mediators high-mobility group box 1 (HMGB1), syndecan-1 (SDC-1), and C3a have been previously proposed as potential biomarkers. For this study, we analyzed these biomarkers in animals undergoing smoke inhalation and 40% total body surface area burns, followed by intensive care for 72 h post-injury (PI) to determine their association with ARDS and mortality. We found that the levels of inflammatory mediators in serum were affected, as well as the degree of HMGB1 and Toll-like receptor 4 (TLR4) signal activation in the lung. The results showed significantly increased HMGB1 expression levels in animals that developed ARDS compared with those that did not. Receiver operating characteristic (ROC) analysis showed that HMGB1 levels at 6 h PI were significantly associated with ARDS development (AUROC=0.77) and mortality (AUROC=0.82). Logistic regression analysis revealed that levels of HMGB1 ≥24.10 ng/ml are associated with a 13-fold higher incidence of ARDS [OR:13.57 (2.76-104.3)], whereas the levels of HMGB1 ≥31.39 ng/ml are associated with a 12-fold increase in mortality [OR: 12.00 (2.36-93.47)]. In addition, we found that mesenchymal stem cell (MSC) therapeutic treatment led to a significant decrease in systemic HMGB1 elevation but failed to block SDC-1 and C3a increases. Immunohistochemistry analyses showed that smoke inhalation and burn injury induced the expression of HMGB1 and TLR4 and stimulated co-localization of HMGB1 and TLR4 in the lung. Interestingly, MSC treatment reduced the presence of HMGB1, TLR4, and the HMGB1-TLR4 co-localization. These results show that serum HMGB1 is a prognostic biomarker for predicting the incidence of ARDS and mortality in swine with smoke inhalation and burn injury. Therapeutically blocking HMGB1 signal activation might be an effective approach for attenuating ARDS development in combat casualties or civilian patients.

Maytenus octogona Superoxide Scavenging and Anti-Inflammatory Caspase-1 Inhibition Study Using Cyclic Voltammetry and Computational Docking Techniques

The relationship between oxidative stress and inflammation is well known, and exogenous antioxidants, primarily phytochemical natural products, may assist the body's endogenous defense systems in preventing diseases due to excessive inflammation. In this study, we evaluated the antioxidant properties of ethnomedicines from Peru that exhibit anti-inflammatory activity by measuring the superoxide scavenging activity of ethanol extracts of Maytenus octogona aerial parts using hydrodynamic voltammetry at a rotating ring-disk electrode (RRDE). The chemical compositions of these extracts are known and the interactions of three methide-quinone compounds found in Maytenus octogona with caspase-1 were analyzed using computational docking studies. Caspase-1 is a critical enzyme triggered during the activation of the inflammasome and its actions are associated with excessive release of cytokines. The most important amino acid involved in active site caspase-1 inhibition is Arg341 and, through docking calculations, we see that this amino acid is stabilized by interactions with the three potential methide-quinone Maytenus octogona inhibitors, hydroxytingenone, tingenone, and pristimerin. These findings were also confirmed after more rigorous molecular dynamics calculations. It is worth noting that, in these three compounds, the methide-quinone carbonyl oxygen is the preferred hydrogen bond acceptor site, although tingenone's other carbonyl group also shows a similar binding energy preference. The results of these calculations and cyclovoltammetry studies support the effectiveness and use of anti-inflammatory ethnopharmacological ethanol extract of Maytenus octogona (L'Héritier) DC.

Theory and Practice of Glucocorticoids in COVID-19: Getting to the Heart of the Matter-A Critical Review and Viewpoints

Prolonged, low-dose glucocorticoids (GCs) have shown the highest efficacy among pharmacological and non-pharmacological treatments for COVID-19. Despite the World Health Organization's recommendation against their use at the beginning of the pandemic, GCs at a dose equivalent to dexamethasone 6 mg/day for 10 days are now indicated in all COVID-19 cases who require respiratory support. However, the efficacy of the intervention depends on the timing of initiation, the dose, and other individual factors. Indeed, patients treated with similar GC protocols often experience different outcomes, which do not always correlate with the presence of comorbidities or with the severity of respiratory involvement at baseline. This prompted us to critically review the literature on the rationale, pharmacological principles, and clinical evidence that should guide GC treatment. Based on these data, the best treatment protocol probably involves an initial bolus dose to saturate the glucocorticoid receptors, followed by a continuous infusion to maintain constant plasma levels, and eventually a slow tapering to interruption. Methylprednisolone has shown the highest efficacy among different GC molecules, most likely thanks to its higher ability to penetrate the lung. Decreased tissue sensitivity to glucocorticoids is thought to be the main mechanism accounting for the lower response to the treatment in some individuals. We do not have a readily available test to identify GC resistance; therefore, to address inter-individual variability, future research should aim at investigating clinical, physiological, and laboratory markers to guide a personalized GC treatment approach.

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.

The Clinical Effects of Laser Acupuncture on Hospitalized Patients With Severe COVID-19: A Randomized Clinical Trial

Introduction: The coronavirus disease (COVID-19) was extended to the entire population in China and around the world, and its mortality rate was about 3.4%. The impact of laser therapy on chronic respiratory diseases has been shown in previous studies. This study was aimed at examining the effects of laser acupuncture (LA) on patients with severe COVID-19. Methods: In the present study, 60 patients with a positive reverse transcription-polymerase chain reaction (RT-PCR) test were assigned to the intervention and control groups (30 patients in each group). The intervention group was treated with LA, that is, laser light with low energy on acupuncture points, once a day for five consecutive days. Results: The participants' mean age in the intervention and control groups was 48.96±12.65 and 53.16±12.28 respectively; 70% of the patients were male and 30% of them were female. IL6 had a significant reduction in the intervention group (P value=0.038) in comparison with the control group (P value=0.535). Furthermore, the mean admission time in the control group was significantly higher than that in the intervention group (P value=0.047). However, the mortality rate in the intervention group was zero, but three patients in the control group died. Conclusion: Our study showed that LA can be used as supportive therapy for routine treatment in patients with severe COVID-19. Moreover, due to LA safety and it's low cost, it could be recommended as an adjuvant to conventional therapy in patients interested in treating their disease with such a method.

A Systematic Review and Meta-analysis of Clinical, Respiratory, and Biochemical Risk Factors for Acute Exacerbation of idiopathic Pulmonary Fibrosis

BACKGROUND

A better capacity to identify patients with idiopathic pulmonary fibrosis (IPF) at risk of acute exacerbation (AEIPF) might improve outcomes and reduce healthcare costs.

AIMS

We critically appraised the available evidence of the differences in clinical, respiratory, and biochemical parameters between AEIPF and IPF patients with stable disease (SIPF) by conducting a systematic review and meta-analysis.

METHODS

PubMed, Web of Science and Scopus were reviewed up until August 1, 2022, for studies reporting differences in clinical, respiratory, and biochemical parameters (including investigational biomarkers) between AEIPF and SIPF patients. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the risk of bias.

RESULTS

Twenty-nine cross-sectional studies published between 2010 and 2022 were identified (all with a low risk of bias). Of the 32 meta-analysed parameters, significant differences were observed between groups, assessed through standard mean differences or relative ratios, with age, forced vital capacity, vital capacity, carbon monoxide diffusion capacity, total lung capacity, oxygen partial pressure, alveolar-arterial oxygen gradient, P/F ratio, 6 min walk test distance, C-reactive protein, lactate dehydrogenase, white blood cell count, albumin, Krebs von den Lungen 6, surfactant protein D, high mobility group box 1 protein, and interleukin-1β, 6, and 8.

CONCLUSIONS

We identified significant differences between AEIPF and SIPF patients in age and specific parameters of respiratory function, inflammation, and epithelial lung damage. Prospective studies are warranted to determine the capacity of these parameters to predict AEIPF more accurately (PROSPERO registration number: CRD42022356640).

Sensitization of GSH synthesis by curcumin curtails acrolein-induced alveolar epithelial apoptosis via Keap1 cysteine conjugation: A randomized controlled trial and experimental animal model of pneumonitis

INTRODUCTION

Epidemiological studies have reported an association between exposures to ambient air pollution and respiratory diseases, including chronic obstructive pulmonary disease (COPD). Pneumonitis is a critical driving factor of COPD and exposure to air pollutants (e.g., acrolein) is associated with increased incidence of pneumonitis.

OBJECTIVES

Currently available anti-inflammatory therapies provide little benefit against respiratory diseases. To this end, we investigated the preventive role of curcumin against air pollutant-associated pneumonitis and its underlying mechanism.

METHODS

A total of 40 subjects was recruited from Chengdu, China which is among the top three cities in terms of respiratory mortality related to air pollution. The participants were randomly provided either placebo or curcumin supplements for 2 weeks and blood samples were collected at the baseline and at the end of the intervention to monitor systemic markers. In our follow up mechanistic study, C57BL/6 mice (n = 40) were randomly allocated into 4 groups: Control group (saline + no acrolein), Curcumin only group (curcumin + no acrolein), Acrolein only group (saline + acrolein), and Acrolein + Curcumin group (curcumin + acrolein). Curcumin was orally administered at 100 mg/kg body weight once a day for 10 days, and then the mice were subjected to nasal instillation of acrolein (5 mg/kg body weight). Twelve hours after single acrolein exposure, all mice were euthanized.

RESULTS

Curcumin supplementation, with no noticeable adverse responses, reduced circulating pro-inflammatory cytokines in association with clinical pneumonitis as positive predictive while improving those of anti-inflammatory cytokines. In the pre-clinical study, curcumin reduced pneumonitis manifestations by suppression of intrinsic and extrinsic apoptotic signaling, which is attributed to enhanced redox sensing of Nrf2 and thus sensitized synthesis and restoration of GSH, at least in part, through curcumin-Keap1 conjugation.

CONCLUSIONS

Our study collectively suggests that curcumin could provide an effective preventive measure against air pollutant-enhanced pneumonitis and thus COPD.

Longitudinal Assessment of Chest CT Findings and Pulmonary Function in Patients after COVID-19

Background Information on pulmonary sequelae and pulmonary function at 2 years post recovery from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are lacking. Purpose To longitudinally assess changes in chest CT abnormities and pulmonary function in patients after SARS-CoV-2 infection. Materials and Methods In this prospective study, patients discharged from the hospital after SARS-CoV-2 infection between January 15 and March 10, 2020 were considered for enrollment. Patients without chest CT scans on admission or with complete resolution of lung abnormities on discharge were excluded. Three serial chest CT scans and pulmonary function tests were obtained at 6 months (June 20-August 31, 2020), 12 months (December 20, 2020-February 3, 2021), and 2 years (November 16, 2021-January 10, 2022) after symptom onset. The term interstitial lung abnormalities (ILAs) and two subcategories, fibrotic ILAs and non-fibrotic ILAs, were used to describe the residual CT abnormalities on follow-up CT scans. Differences between groups were compared with χ², Fisher's exact test, or independent-samples t-test. Results Totally, 144 participants (median age, 60 [ranges 27-80] years; 79 men and 65 women) were included. On 2-year follow-up CT scans, 39% (56/144) of the subjects presented with ILAs, including 23% (33/144) wi fibrotic ILAs and 16% (23/144) with non-fibrotic ILAs. The remaining 88 cases (61%) showed complete radiological resolution. Over 2 years, the incidence of ILAs gradually decreased (54%, 42% and 39% at 6 months, 12 months and 2 years, respectively; P = .001). Respiratory symptoms (34% vs 15%, P =.007) and abnormal diffusing capacity of the lung for carbon monoxide (DLco,43% vs 20%, P = .004) more frequently occurred in participants with ILAs than those with complete radiological resolution. Conclusions More than one third of participants had persistent interstitial lung abnormalities at 2 years, which were associated with respiratory symptoms and decreased diffusion pulmonary function. See also the editorial by van Beek in this issue.

Anti-inflammatory and antioxidant activities of Gymnema Sylvestre extract rescue acute respiratory distress syndrome in rats via modulating the NF-κB/MAPK pathway

Acute respiratory distress syndrome (ARDS) is one of the major causes of mortality in COVID-19 patients, due to limited therapeutic options. This prompted us to explore natural sources to mitigate this condition. Gymnema Sylvestre (GS) is an ancient medicinal plant known to have various therapeutic effects. This investigation examined the therapeutic effect of hydroalcoholic extract of Gymnema Sylvestre (HAEGS) against lipopolysaccharide (LPS)-induced lung injury and ARDS in in vitro and in vivo models. UHPLC-HRMS/GC-MS was employed for characterizing the HAEGS and identified several active derivatives including gymnemic acid, gymnemasaponins, gymnemoside, gymnemasin, quercetin, and long fatty acids. Gene expression by RT-qPCR and DCFDA analysis by flow cytometry revealed that several inflammatory cytokine/chemokine, cell injury markers, and reactive oxygen species (ROS) levels were highly upregulated in LPS control and were significantly reduced upon HAEGS treatment. Consistent with the in vitro studies, we found that in LPS-induced ARDS model, pre-treatment with HAEGS significantly suppressed the LPS-induced elevation of inflammatory cell infiltrations, cytokine/chemokine marker expression, ROS levels, and lung injury in a dose-dependent manner. Further mechanistic studies demonstrated that HAEGS suppressed oxidative stress by modulating the NRF2 pathway and ameliorated the ARDS through the NF-κB/MAPK signalling pathway. Additional fractionation results revealed that fraction 6 which has the exclusive composition of gymnemic acid derivatives showed better anti-inflammatory effects (inhibition of IL-6 and IL-1β) at lower concentrations compared to HAEGS. Overall, HAEGS significantly mitigated LPS-induced lung injury and ARDS by targeting the NF-κB/MAPK signalling pathway. Thus, our work unravels the protective role of HAEGS for the first time in managing ARDS.

Biological Markers to Predict Outcome in Mechanically Ventilated Patients with Severe COVID-19 Living at High Altitude

BACKGROUND

There is not much evidence on the prognostic utility of different biological markers in patients with severe COVID-19 living at high altitude. The objective of this study was to determine the predictive value of inflammatory and hematological markers for the risk of mortality at 28 days in patients with severe COVID-19 under invasive mechanical ventilation, living at high altitude and in a low-resource setting.

METHODS

We performed a retrospective observational study including patients with severe COVID-19, under mechanical ventilation and admitted to the intensive care unit (ICU) located at 2850 m above sea level, between 1 April 2020 and 1 August 2021. Inflammatory (interleukin-6 (IL-6), ferritin, D-dimer, lactate dehydrogenase (LDH)) and hematologic (mean platelet volume (MPV), neutrophil/lymphocyte ratio (NLR), MPV/platelet ratio) markers were evaluated at 24 h and in subsequent controls, and when available at 48 h and 72 h after admission to the ICU. The primary outcome was the association of inflammatory and hematological markers with the risk of mortality at 28 days.

RESULTS

We analyzed 223 patients (median age (1st quartile [Q1]-3rd quartile [Q3]) 51 (26-75) years and 70.4% male). Patients with severe COVID-19 and with IL-6 values at 24 h ≥ 11, NLR values at 24 h ≥ 22, and NLR values at 72 h ≥ 14 were 8.3, 3.8, and 3.8 times more likely to die at 28 days, respectively. The SOFA and APACHE-II scores were not able to independently predict mortality.

CONCLUSIONS

In mechanically ventilated patients with severe COVID-19 and living at high altitude, low-cost and immediately available blood markers such as IL-6 and NLR may predict the severity of the disease in low-resource settings.

Growth Hormone-Releasing Hormone in Endothelial Inflammation

The discovery of hypothalamic hormones propelled exciting advances in pharmacotherapy and improved life quality worldwide. Growth hormone-releasing hormone (GHRH) is a crucial element in homeostasis maintenance, and regulates the release of growth hormone from the anterior pituitary gland. Accumulating evidence suggests that this neuropeptide can also promote malignancies, as well as inflammation. Our review is focused on the role of that 44 - amino acid peptide (GHRH) and its antagonists in inflammation and vascular function, summarizing recent findings in the corresponding field. Preclinical studies demonstrate the protective role of GHRH antagonists against endothelial barrier dysfunction, suggesting that the development of those peptides may lead to new therapies against pathologies related to vascular remodeling (eg, sepsis, acute respiratory distress syndrome). Targeted therapies for those diseases do not exist.

Decreased cardiovascular risk factors and inflammation with remission of type 2 diabetes in adults with obesity using a high protein diet: Randomized control trial

Objective

The study objective was to determine the effects a high protein (HP) vs. a high carbohydrate (HC) diet on cardiovascular risk factors (CVR), inflammation, metabolic parameters, oxidative stress, weight loss, lean and fat body mass, and remission of Type 2 Diabetes (T2DM) in subjects with obesity.

Research design and methods

Twelve women and men with T2D were recruited and randomized to either a HP (30%protein, 30%fat, 40%carbohydrate) (n = 6) or HC (15%protein, 30%fat, 55%carbohydrate) (n = 6) diet feeding study for 6 months in this randomized controlled trial. All meals were purchased at local grocery stores and provided to subjects for 6 months with daily food menus for HP or HC compliance with weekly food pick-up and weight measurements. Oral glucose tolerance and meal tolerance tests with glucose and insulin measurements and DXA scans were done at baseline and after 6 months on the respective diets.

Results

After 6 months on the HP diet, 100% of the subjects had remission of their T2DM to Normal Glucose Tolerance (NGT), whereas only 16.6% of subjects on the HC diet had remission of their T2DM. The HP diet group exhibited significant improvement in a) cardiovascular risk factors (p = 0.004, b) inflammatory cytokines(p = 0.001), c) insulin sensitivity(p = 0.001), d) oxidative stress(p = 0.001), e) increased %lean body mass(p = 0.001) compared to the HC diet group at 6 months.

Conclusions

A significant improvement in cardiovascular risk factors, inflammation, metabolic parameters and 100% remission of T2DM to NGT was achieved with a HP diet compared to a HC diet at 6 months.

Clinicaltrialsgov identifier

NCT01642849.

Assessing organ-level immunoreactivity in a rat model of sepsis using TSPO PET imaging

There is current need for new approaches to assess/measure organ-level immunoreactivity and ensuing dysfunction in systemic inflammatory response syndrome (SIRS) and sepsis, in order to protect or recover organ function. Using a rat model of systemic sterile inflammatory shock (intravenous LPS administration), we performed PET imaging with a translocator protein (TSPO) tracer, [¹⁸F]DPA-714, as a biomarker for reactive immunoreactive changes in the brain and peripheral organs. In vivo dynamic PET/CT scans showed increased [¹⁸F]DPA-714 binding in the brain, lungs, liver and bone marrow, 4 hours after LPS injection. Post-LPS mean standard uptake values (SUV_mean) at equilibrium were significantly higher in those organs compared to baseline. Changes in spleen [¹⁸F]DPA-714 binding were variable but generally decreased after LPS. SUV_mean values in all organs, except the spleen, positively correlated with several serum cytokines/chemokines. In vitro measures of TSPO expression and immunofluorescent staining validated the imaging results. Noninvasive molecular imaging with [¹⁸F]DPA-714 PET in a rat model of systemic sterile inflammatory shock, along with in vitro measures of TSPO expression, showed brain, liver and lung inflammation, spleen monocytic efflux/lymphocytic activation and suggested increased bone marrow hematopoiesis. TSPO PET imaging can potentially be used to quantify SIRS and sepsis-associated organ-level immunoreactivity and assess the effectiveness of therapeutic and preventative approaches for associated organ failures, in vivo.

A clinically relevant model of acute respiratory distress syndrome in human-size swine

Despite over 30 years of intensive research for targeted therapies, treatment of acute respiratory distress syndrome (ARDS) remains supportive in nature. With mortality upwards of 30%, a high-fidelity pre-clinical model of ARDS, on which to test novel therapeutics, is urgently needed. We used the Yorkshire breed of swine to induce a reproducible model of ARDS in human-sized swine to allow the study of new therapeutics, from both mechanistic and clinical standpoints. For this, animals were anesthetized, intubated and mechanically ventilated, and pH-standardized gastric contents were delivered bronchoscopically, followed by intravenous infusion of Escherichia coli-derived lipopolysaccharide. Once the ratio of arterial oxygen partial pressure (PaO2) to fractional inspired oxygen (FIO2) had decreased to <150, the animals received standard ARDS treatment for up to 48 h. All swine developed moderate to severe ARDS. Chest radiographs taken at regular intervals showed significantly worse lung edema after induction of ARDS. Quantitative scoring of lung injury demonstrated time-dependent increases in interstitial and alveolar edema, neutrophil infiltration, and mild to moderate alveolar membrane thickening. This pre-clinical model of ARDS in human-sized swine recapitulates the clinical, radiographic and histopathologic manifestations of ARDS, providing a tool to study therapies for this highly morbid lung disease.

Innate Immune Response and Inflammasome Activation During SARS-CoV-2 Infection

The novel coronavirus SARS-CoV-2, responsible for the COVID-19 outbreak, has become a pandemic threatening millions of lives worldwide. Recently, several vaccine candidates and drugs have shown promising effects in preventing or treating COVID-19, but due to the development of mutant strains through rapid viral evolution, urgent investigations are warranted in order to develop preventive measures and further improve current vaccine candidates. Positive-sense-single-stranded RNA viruses comprise many (re)emerging human pathogens that pose a public health problem. Our innate immune system and, in particular, the interferon response form an important first line of defense against these viruses. Flexibility in the genome aids the virus to develop multiple strategies to evade the innate immune response and efficiently promotes their replication and infective capacity. This review will focus on the innate immune response to SARS-CoV-2 infection and the virus' evasion of the innate immune system by escaping recognition or inhibiting the production of an antiviral state. Since interferons have been implicated in inflammatory diseases and immunopathology along with their protective role in infection, antagonizing the immune response may have an ambiguous effect on the clinical outcome of the viral disease. This pathology is characterized by intense, rapid stimulation of the innate immune response that triggers activation of the Nod-like receptor family, pyrin-domain-containing 3 (NLRP3) inflammasome pathway, and release of its products including the pro-inflammatory cytokines IL-6, IL-18, and IL-1β. This predictive view may aid in designing an immune intervention or preventive vaccine for COVID-19 in the near future.

Effects of tocilizumab and dexamethasone on the downregulation of proinflammatory cytokines and upregulation of antioxidants in the lungs in oleic acid-induced ARDS

Background

Acute respiratory distress syndrome (ARDS) is a life-threatening disease caused by the induction of inflammatory cytokines and chemokines in the lungs. There is a dearth of drug applications that can be used to prevent cytokine storms in ARDS treatment. This study was designed to investigate the effects of tocilizumab and dexamethasone on oxidative stress, antioxidant parameters, and cytokine storms in acute lung injury caused by oleic acid in rats.

Methods

Adult male rats were divided into five groups: the CN (healthy rats, n = 6), OA (oleic acid administration, n = 6), OA + TCZ-2 (oleic acid and tocilizumab at 2 mg/kg, n = 6), OA + TCZ-4 (oleic acid and tocilizumab at 4 mg/kg, n = 6), and OA + DEX-10 (oleic acid and dexamethasone at 10 mg/kg, n = 6) groups. All animals were euthanized after treatment for histopathological, immunohistochemical, biochemical, PCR, and SEM analyses.

Results

Expressions of TNF-α, IL-1β, IL-6, and IL-8 cytokines in rats with acute lung injury induced by oleic acid were downregulated in the TCZ and DEX groups compared to the OA group (P < 0.05). The MDA level in lung tissues was statistically lower in the OA + TCZ-4 group compared to the OA group. It was further determined that SOD, GSH, and CAT levels were decreased in the OA group and increased in the TCZ and DEX groups (P < 0.05). Histopathological findings such as thickening of the alveoli, hyperemia, and peribronchial cell infiltration were found to be similar when lung tissues of the TCZ and DEX groups were compared to the control group. With SEM imaging of the lung tissues, it was found that the alveolar lining layer had become indistinct in the OA, OA + TCZ-2, and OA + TCZ-4 groups.

Conclusions

In this model of acute lung injury caused by oleic acid, tocilizumab and dexamethasone were effective in preventing cytokine storms by downregulating the expression of proinflammatory cytokines including TNF-α, IL-1β, IL-6, and IL-8. Against the downregulation of antioxidant parameters such as SOD and GSH in the lung tissues caused by oleic acid, tocilizumab and dexamethasone upregulated them and showed protective effects against cell damage.

Systemic interleukin-6 inhibition ameliorates acute neuropsychiatric phenotypes in a murine model of acute lung injury

Acute neuropsychiatric impairments occur in over 70% of patients with acute lung injury. Mechanical ventilation is a well-known precipitant of acute lung injury and is strongly associated with the development of acute delirium and anxiety phenotypes. In prior studies, we demonstrated that IL-6 mediates neuropathological changes in the frontal cortex and hippocampus of animals with mechanical ventilation-induced brain injury; however, the effect of systemic IL-6 inhibition on structural and functional acute neuropsychiatric phenotypes is not known. We hypothesized that a murine model of mechanical ventilation-induced acute lung injury (VILI) would induce neural injury to the amygdala and hippocampus, brain regions that are implicated in diverse neuropsychiatric conditions, and corresponding delirium- and anxiety-like functional impairments. Furthermore, we hypothesized that these structural and functional changes would reverse with systemic IL-6 inhibition. VILI was induced using high tidal volume (35 cc/kg) mechanical ventilation. Cleaved caspase-3 (CC3) expression was quantified as a neural injury marker and found to be significantly increased in the VILI group compared to spontaneously breathing or anesthetized and mechanically ventilated mice with 10 cc/kg tidal volume. VILI mice treated with systemic IL-6 inhibition had significantly reduced amygdalar and hippocampal CC3 expression compared to saline-treated animals and demonstrated amelioration in acute neuropsychiatric behaviors in open field, elevated plus maze, and Y-maze tests. Overall, these data provide evidence of a pathogenic role of systemic IL-6 in mediating structural and functional acute neuropsychiatric symptoms in VILI and provide preclinical justification to assess IL-6 inhibition as a potential intervention to ameliorate acute neuropsychiatric phenotypes following VILI.

Renalase Challenges the Oxidative Stress and Fibroproliferative Response in COVID-19

The hallmark of the coronavirus disease 2019 (COVID-19) pathophysiology was reported to be an inappropriate and uncontrolled immune response, evidenced by activated macrophages, and a robust surge of proinflammatory cytokines, followed by the release of reactive oxygen species, that synergistically result in acute respiratory distress syndrome, fibroproliferative lung response, and possibly even death. For these reasons, all identified risk factors and pathophysiological processes of COVID-19, which are feasible for the prevention and treatment, should be addressed in a timely manner. Accordingly, the evolving anti-inflammatory and antifibrotic therapy for severe COVID-19 and hindering post-COVID-19 fibrosis development should be comprehensively investigated. Experimental evidence indicates that renalase, a novel amino-oxidase, derived from the kidneys, exhibits remarkable organ protection, robustly addressing the most powerful pathways of cell trauma: inflammation and oxidative stress, necrosis, and apoptosis. As demonstrated, systemic renalase administration also significantly alleviates experimentally induced organ fibrosis and prevents adverse remodeling. The recognition that renalase exerts cytoprotection via sirtuins activation, by raising their NAD⁺ levels, provides a “proof of principle” for renalase being a biologically impressive molecule that favors cell protection and survival and maybe involved in the pathogenesis of COVID-19. This premise supports the rationale that renalase's timely supplementation may prove valuable for pathologic conditions, such as cytokine storm and related acute respiratory distress syndrome. Therefore, the aim for this review is to acknowledge the scientific rationale for renalase employment in the experimental model of COVID-19, targeting the acute phase mechanisms and halting fibrosis progression, based on its proposed molecular pathways. Novel therapies for COVID-19 seek to exploit renalase's multiple and distinctive cytoprotective mechanisms; therefore, this review should be acknowledged as the thorough groundwork for subsequent research of renalase's employment in the experimental models of COVID-19.