Systemic Endothelial Activation Is Associated With Early Acute Respiratory Distress Syndrome in Children With Extrapulmonary Sepsis

The predictive value of endocan as a novel biomarker: an umbrella study on meta-analyses

BACKGROUND AND AIM

In recent years, endocan has emerged as a potential biomarker in various medical conditions. This multifaceted molecule, involved in key processes such as inflammation and endothelial dysfunction, has shown promise in predicting disease progression and therapeutic response across a spectrum of pathologies. However, the heterogeneity of studies and the complexity of endocan's role in different diseases necessitate a comprehensive review. This umbrella review aimed to systematically synthesize and evaluate the evidence from multiple meta-analyses, offering a view of endocan's effectiveness as a predictive biomarker in medical diseases.

METHODS

An extensive search was carried out on March 12, 2024, using the following four databases: PubMed, Scopus, Web of Science, and Cochrane Library. The goal was to identify meta-analyses that assess endocan's predictive efficacy. The pooled effect size and its 95% confidence interval were taken out of each discovered meta-analysis. Furthermore, power analyses were performed to assess the robustness and dependability of the results. An additional GRADE assessment was carried out to gauge the epidemiological reliability of the findings.

RESULTS

In the final analysis, 12 meta-analyses were included in the current umbrella review. The results showed that there is a significant correlation between a higher endocan level and COVID-19 (SMD: 1.40, 95% CI 0.21-2.58, P = 0.02), followed by chronic kidney disease (SMD: 1.34, 95% CI 0.20 to 2.48, P < 0.01), obstructive sleep apnea (SMD: 1.30, 95% CI 1.06-1.54, P < 0.01), diabetes mellitus (SMD: 1.00, 95% CI 0.81 to 1.19, P < 0.01), coronary artery disease (SMD: 0.99, 95% CI 0.58-1.39, P < 0.01), hypertension (SMD: 0.91, 95% CI 0.44-1.38, P < 0.01), and preeclampsia (SMD: 0.37, 95% CI 0.13-0.62, P < 0.01).

CONCLUSION

Endocan has emerged as a highly promising biomarker with considerable potential across various medical conditions. Its relevance spans critical areas such as COVID-19, chronic kidney disease, obstructive sleep apnea, diabetes mellitus, coronary artery disease, and preeclampsia. The broad applicability of endocan highlights its value in improving diagnostic accuracy and enhancing our understanding of these diseases. Clinically, incorporating endocan testing could aid in early detection, monitoring disease progression, and refining patient management, particularly for high-risk populations. However, additional research is needed to fully assess its specificity, sensitivity, and overall clinical utility, paving the way for its integration into routine healthcare practices and enabling more precise, individualized treatment strategies.

Derivation and Validation of a Clinical and Endothelial Biomarker Risk Model to Predict Persistent Pediatric Sepsis-Associated Acute Respiratory Dysfunction

BACKGROUND

Sepsis-associated ARDS results in high morbidity and mortality in children. However, heterogeneity among patients makes identifying those at risk of persistent acute respiratory dysfunction challenging. Endothelial dysfunction is a key feature of ARDS pathophysiologic characteristics, contributing to lung injury in sepsis. Incorporating endothelial biomarkers into risk models may enhance prediction of those with persistent acute respiratory dysfunction.

RESEARCH QUESTION

Can clinical variables and endothelial biomarkers measured early in the course of sepsis predict risk of persistent acute respiratory dysfunction among critically ill children?

STUDY DESIGN AND METHODS

This was a multicenter derivation and single center test cohort study of prospectively enrolled children with sepsis. The derivation cohort was split into training and holdout validation sets. We trained TreeNet (Minitab, LLC) and classification and regression tree (CART) models using clinical and endothelial biomarkers measured on day 1 of septic shock to predict risk of sepsis-associated acute respiratory dysfunction (SA ARD) on day 3. The performance of the CART model was tested in the holdout validation data set and in the independent test cohort.

RESULTS

In the derivation (n = 625) and test (n = 162) cohorts, children with day 3 SA ARD showed increased mortality, length of mechanical ventilation, and PICU length of stay compared with those without. The TreeNet and CART models yielded comparable results. The variables included in the final CART model were presence of SA ARD on day 1, Pao2 to Fio2 ratio of < 250, soluble thrombomodulin, and vascular cell adhesion molecule 1 concentrations. This model showed an area under the receiver operating characteristic curve (AUC) of 0.88 in the training data set, sensitivity of 0.91 (95% CI, 0.86-0.94), specificity of 0.76 (95% CI, 0.68-0.82), and demonstrated reproducibility in validation data set and test cohort (AUC range, 0.78-0.83).

INTERPRETATION

We derived and validated predictive models incorporating clinical and endothelial biomarkers to identify pediatric patients with septic shock at high risk of persistent acute respiratory dysfunction. Pending prospective validation, such models may facilitate enrichment and targeted intervention in future clinical trials.

Vascular endothelial cell injury: causes, molecular mechanisms, and treatments

Vascular endothelial cells form a single layer of flat cells that line the inner surface of blood vessels, extending from large vessels to the microvasculature of various organs. These cells are crucial metabolic and endocrine components of the body, playing vital roles in maintaining circulatory stability, regulating vascular tone, and preventing coagulation and thrombosis. Endothelial cell injury is regarded as a pivotal initiating factor in the pathogenesis of various diseases, triggered by multiple factors, including infection, inflammation, and hemodynamic changes, which significantly compromise vascular integrity and function. This review examines the causes, underlying molecular mechanisms, and potential therapeutic approaches for endothelial cell injury, focusing specifically on endothelial damage in cardiac ischemia/reperfusion (I/R) injury, sepsis, and diabetes. It delves into the intricate signaling pathways involved in endothelial cell injury, emphasizing the roles of oxidative stress, mitochondrial dysfunction, inflammatory mediators, and barrier damage. Current treatment strategies-ranging from pharmacological interventions to regenerative approaches and lifestyle modifications-face ongoing challenges and limitations. Overall, this review highlights the importance of understanding endothelial cell injury within the context of various diseases and the necessity for innovative therapeutic methods to improve patient outcomes.

Advances and Challenges in Pediatric Sepsis Diagnosis: Integrating Early Warning Scores and Biomarkers for Improved Prognosis

Identifying and managing pediatric sepsis is a major research focus, yet early detection and risk assessment remain challenging. In its early stages, sepsis symptoms often mimic those of mild infections or chronic conditions, complicating timely diagnosis. Although various early warning scores exist, their effectiveness is limited, particularly in prehospital settings where accurate, rapid assessment is crucial. This review examines the roles of clinical prediction tools and biomarkers in pediatric sepsis. Traditional biomarkers, like procalcitonin (PCT), have improved diagnostic accuracy but are insufficient alone, often resulting in overprescription of antibiotics or delayed treatment. Combining multiple biomarkers has shown promise for early screening, though this approach can be resource-intensive and less feasible outside hospitals. Predicting sepsis outcomes to tailor therapy remains underexplored. While serial measurements of traditional biomarkers offer some prognostic insight, their reliability is limited, with therapeutic decisions often relying on clinical judgment. Novel biomarkers, particularly those identifying early organ dysfunction, hold potential for improved prognostic accuracy, but significant barriers remain. Many are only available in hospitals, require further validation, or need specialized assays not commonly available, limiting broader clinical use. Further research is needed to establish reliable protocols and enhance the clinical applicability of these tools. Meanwhile, a multifaceted approach that combines clinical judgment with existing tools and biomarkers remains essential to optimize pediatric sepsis management, improving outcomes and minimizing risks.

Comparative analysis of compartment-specific immunothrombotic biomarker profiles in bronchoalveolar lavage fluid and serum of patients with pneumonia-related acute respiratory distress syndrome: A preliminary cross-sectional study

Immunothrombosis has emerged as a potential mechanistic link underlying the development and progression of acute respiratory distress syndrome (ARDS), but understanding its specific profile in patients, both locally and systemically, is limited. The objective of this study was to characterize and compare the immunothrombotic signatures in patients diagnosed with pneumonia-related ARDS (p-ARDS) at both the pulmonary and systemic levels and to evaluate their clinical relevance. The study included 23 consecutive patients diagnosed with p-ARDS admitted to the intensive care unit at a tertiary university hospital from July 2022 to May 2023, alongside 40 concurrently hospitalized patients with common pneumonia as controls. Paired bronchoalveolar lavage fluid (BALF) and serum samples were collected from the participants for the analysis of 15 biomarkers to assess and quantify the pulmonary and systemic immunothrombotic signatures. The study results revealed significant pulmonary inflammation and systemic endothelial injury in p-ARDS patients compared to pneumonia controls. These observations were maintained after adjustment for severity of illness (Acute Physiology and Chronic Health Evaluation II scores). In terms of clinical relevance, inflammatory biomarkers (interleukin [IL]-6, IL-8) in BALF were found to correlate with PaO2/FiO2 ratio, while serum levels of a disintegrin and metalloproteinase with thrombospondin type 1 motif 13 (ADAMTS-13) and thrombomodulin showed associations with Sequential Organ Failure Assessment and Disseminated Intravascular Coagulation scores. In conclusion, this preliminary investigation identified compartment-specific variations in the immunothrombotic signature between patients with p-ARDS and those with pneumonia alone, with inflammatory responses predominantly localized in the alveolar compartments and coagulation/endothelial injury biomarkers more pronounced in peripheral blood.

Sepsis-induced coagulopathy (SIC) in the management of sepsis

The mortality rate of sepsis remains high and further increases when complicated by disseminated intravascular coagulation (DIC). Consequently, early detection and appropriate management of DIC will be helpful for the management of sepsis. Although overt DIC criteria are often used for diagnosing definitive DIC, it was not designed to detect early-phase DIC. The criteria and scoring system for sepsis-induced coagulopathy (SIC) were developed and introduced in 2017 to detect early-stage DIC, and they were subsequently adopted by the International Society on Thrombosis and Haemostasis in 2019. The objective of detecting SIC was not to miss the patients at high risk of developing overt DIC at an earlier time. Although anticoagulant therapies are potential options for the treatment of sepsis-associated DIC, their effectiveness has not been established, and further research is warranted. For that purpose, an international collaborative platform is required for future clinical trials, and SIC criteria have been suggested for such studies. Calculating the SIC score is straightforward and suitable for use in clinical settings. This review aims to introduce SIC criteria and its scoring system for better management of sepsis-associated DIC. We also intended to update the current knowledge regarding this novel diagnostic criterion.

Endothelial dysfunction: Pathophysiology and therapeutic targets for sepsis-induced multiple organ dysfunction syndrome

Sepsis and septic shock are critical medical conditions characterized by a systemic inflammatory response to infection, significantly contributing to global mortality rates. The progression to multiple organ dysfunction syndrome (MODS) represents the most severe complication of sepsis and markedly increases clinical mortality. Central to the pathophysiology of sepsis, endothelial cells play a crucial role in regulating microcirculation and maintaining barrier integrity across various organs and tissues. Recent studies have underscored the pivotal role of endothelial function in the development of sepsis-induced MODS. This review aims to provide a comprehensive overview of the pathophysiology of sepsis-induced MODS, with a specific focus on endothelial dysfunction. It also compiles compelling evidence regarding potential small molecules that could attenuate sepsis and subsequent multi-organ damage by modulating endothelial function. Thus, this review serves as an essential resource for clinical practitioners involved in the diagnosing, managing, and providing intensive care for sepsis and associated multi-organ injuries, emphasizing the importance of targeting endothelial cells to enhance outcomes of the patients.

Endocan as a biomarker for acute respiratory distress syndrome: A systematic review and meta-analysis

Background and Aims

Endocan is a marker of endothelial damage. Data regarding the association of this proteoglycan and acute respiratory distress syndrome (ARDS) is discrepant. Hence, this study sought to investigate the possible correlation between serum/plasma endocan concentration and ARDS.

Methods

A systematic review and meta-analysis of international online databases was conducted following PRISMA guidelines. PubMed, SCOPUS, Embase, and Web of Science were searched in March 2023, with the leading search terms being "ARDS" OR "respiratory distress" AND "endocan" and other associated terms. Studies that measured endocan levels in patients with ARDS and compared it with non-ARDS controls or within different severities of ARDS were included. We performed a random-effect meta-analysis for pooling the differences using standardized mean difference (SMD) and 95% confidence interval (CI).

Results

We included 14 studies involving 1,058 patients. Those developing ARDS had significantly higher levels of endocan compared to those without ARDS (SMD: 0.47, 95% CI: 0.10-0.84, p = 0.01). Our meta-analysis of three studies found that endocan levels in ARDS nonsurvivors were significantly higher than in survivors (SMD: 0.31, 95% CI: 0.02-0.60, p = 0.03). Three studies investigated endocan levels in different severities of ARDS. Only one of these studies reported significantly higher endocan levels in patients with worsening acute respiratory failure at Day 15. The other two reported no significant association between ARDS severity and circulating endocan levels.

Conclusion

Blood endocan levels were significantly higher in patients with ARDS than those without. Additionally, among patients with ARDS, blood endocan values were significantly elevated in nonsurvivors compared to survivors. These findings could help researchers design future studies and solidify these findings and finally, clinicians to take advantage of measuring endocan in clinical settings for assessment of patients with ARDS.

Biomarker-Based Risk Stratification Tool in Pediatric Acute Respiratory Distress Syndrome: Single-Center, Longitudinal Validation in a 2014-2019 Cohort

OBJECTIVES

The Pediatric Acute Respiratory Distress Syndrome Biomarker Risk Model (PARDSEVERE) used age and three plasma biomarkers measured within 24 hours of pediatric acute respiratory distress syndrome (ARDS) onset to predict mortality in a pilot cohort of 152 patients. However, longitudinal performance of PARDSEVERE has not been evaluated, and it is unclear whether the risk model can be used to prognosticate after day 0. We, therefore, sought to determine the test characteristics of PARDSEVERE model and population over the first 7 days after ARDS onset.

DESIGN

Secondary unplanned post hoc analysis of data from a prospective observational cohort study carried out 2014-2019.

SETTING

University-affiliated PICU.

PATIENTS

Mechanically ventilated children with ARDS.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Between July 2014 and December 2019, 279 patients with ARDS had plasma collected at day 0, 266 at day 3 (11 nonsurvivors, two discharged between days 0 and 3), and 207 at day 7 (27 nonsurvivors, 45 discharged between days 3 and 7). The actual prevalence of mortality on days 0, 3, and 7, was 23% (64/279), 14% (38/266), and 13% (27/207), respectively. The PARDSEVERE risk model for mortality on days 0, 3, and 7 had area under the receiver operating characteristic curve (AUROC [95% CI]) of 0.76 (0.69-0.82), 0.68 (0.60-0.76), and 0.74 (0.65-0.83), respectively. The AUROC data translate into prevalence thresholds for the PARDSEVERE model for mortality (i.e., using the sensitivity and specificity values) of 37%, 27%, and 24% on days 0, 3, and 7, respectively. Negative predictive value (NPV) was high throughout (0.87-0.90 for all three-time points).

CONCLUSIONS

In this exploratory analysis of the PARDSEVERE model of mortality risk prediction in a population longitudinal series of data from days 0, 3, and 7 after ARDS diagnosis, the diagnostic performance is in the "acceptable" category. NPV was good. A major limitation is that actual mortality is far below the prevalence threshold for such testing. The model may, therefore, be more useful in cohorts with higher mortality rates (e.g., immunocompromised, other countries), and future enhancements to the model should be explored.

Potential biomarkers used for risk estimation of pediatric sepsis-associated organ dysfunction and immune dysregulation

Pediatric sepsis is a serious issue globally and is a significant cause of illness and death among infants and children. Refractory septic shock and multiple organ dysfunction syndrome are the primary causes of mortality in children with sepsis. However, there is incomplete understanding of mechanistic insight of sepsis associated organ dysfunction. Biomarkers present during the body's response to infection-related inflammation can be used for screening, diagnosis, risk stratification/prognostication, and/or guidance in treatment decision-making. Research on biomarkers in children with sepsis can provide information about the risk of poor outcomes and sepsis-related organ dysfunction. This review focuses on clinically used biomarkers associated with immune dysregulation and organ dysfunction in pediatric sepsis, which could be useful for developing precision medicine strategies in pediatric sepsis management in the future. IMPACT: Sepsis is a complex syndrome with diverse clinical presentations, where organ dysfunction is a key factor in morbidity and mortality. Early detection of organ complications is vital in sepsis management, and potential biomarkers offer promise for precision medicine in pediatric cases. Well-designed studies are needed to identify phase-specific biomarkers and improve outcomes through more precise management.

Pediatric Sepsis Diagnosis, Management, and Sub-phenotypes

Sepsis and septic shock are major causes of morbidity, mortality, and health care costs for children worldwide, including >3 million deaths annually and, among survivors, risk for new or worsening functional impairments, including reduced quality of life, new respiratory, nutritional, or technological assistance, and recurrent severe infections. Advances in understanding sepsis pathophysiology highlight a need to update the definition and diagnostic criteria for pediatric sepsis and septic shock, whereas new data support an increasing role for automated screening algorithms and biomarker combinations to assist earlier recognition. Once sepsis or septic shock is suspected, attention to prompt initiation of broad-spectrum empiric antimicrobial therapy, fluid resuscitation, and vasoactive medications remain key components to initial management with several new and ongoing studies offering new insights into how to optimize this approach. Ultimately, a key goal is for screening to encompass as many children as possible at risk for sepsis and trigger early treatment without increasing unnecessary broad-spectrum antibiotics and preventable hospitalizations. Although the role for adjunctive treatment with corticosteroids and other metabolic therapies remains incompletely defined, ongoing studies will soon offer updated guidance for optimal use. Finally, we are increasingly moving toward an era in which precision therapeutics will bring novel strategies to improve outcomes, especially for the subset of children with sepsis-induced multiple organ dysfunction syndrome and sepsis subphenotypes for whom antibiotics, fluid, vasoactive medications, and supportive care remain insufficient.

Surgical Science and the Evolution of Critical Care Medicine

Surgical science has driven innovation and inquiry across adult and pediatric disciplines that provide critical care regardless of location. Surgically originated but broadly applicable knowledge has been globally shared within the pages Critical Care Medicine over the last 50 years.

Pathobiology, Severity, and Risk Stratification of Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

To review the literature for studies published in children on the pathobiology, severity, and risk stratification of pediatric acute respiratory distress syndrome (PARDS) with the intent of guiding current medical practice and identifying important areas for future research related to severity and risk stratification.

DATA SOURCES

Electronic searches of PubMed and Embase were conducted from 2013 to March 2022 by using a combination of medical subject heading terms and text words to capture the pathobiology, severity, and comorbidities of PARDS.

STUDY SELECTION

We included studies of critically ill patients with PARDS that related to the severity and risk stratification of PARDS using characteristics other than the oxygenation defect. Studies using animal models, adult only, and studies with 10 or fewer children were excluded from our review.

DATA EXTRACTION

Title/abstract review, full-text review, and data extraction using a standardized data collection form.

DATA SYNTHESIS

The Grading of Recommendations Assessment, Development, and Evaluation approach was used to identify and summarize relevant evidence and develop recommendations for clinical practice. There were 192 studies identified for full-text extraction to address the relevant Patient/Intervention/Comparator/Outcome questions. One clinical recommendation was generated related to the use of dead space fraction for risk stratification. In addition, six research statements were generated about the impact of age on acute respiratory distress syndrome pathobiology and outcomes, addressing PARDS heterogeneity using biomarkers to identify subphenotypes and endotypes, and use of standardized ventilator, physiologic, and nonpulmonary organ failure measurements for future research.

CONCLUSIONS

Based on an extensive literature review, we propose clinical management and research recommendations related to characterization and risk stratification of PARDS severity.

Role of Serum Endocan Levels in Children with Bacterial and Viral Pneumonia: A Prospective, Case-Control Study

Introduction and Objective: Endocan has been used as a biomarker in the differential diagnosis of pulmonary diseases in adults. However, there are only a limited number of studies on its use in children. In this context, the objective of this study is to evaluate the relationship between serum endocan levels in children with bacterial and viral pneumonia. Materials and Methods: The population of this prospective case-control study consisted of hospitalized children aged 1 month to 15 years diagnosed with pneumonia between August 2020 and July 2021, whereas the control group consisted of randomly selected healthy children. The demographic and clinical characteristics of all participants were recorded. Participants' endocan levels, white blood cell (WBC) and neutrophil counts, and C-reactive protein (CRP) and procalcitonin (PCT) levels were measured within the scope of the laboratory tests. Results: The study sample consisted of 41 children, of whom 21 had bacterial pneumonia and 20 had viral pneumonia, whereas the control group consisted of 47 healthy children. Serum endocan levels, WBC and neutrophil counts, and PCT and CRP levels were significantly higher in children with bacterial pneumonia than in children with viral pneumonia and healthy children (P < 0.05). Additionally, serum endocan levels were significantly higher in children with viral pneumonia than in healthy children (P < 0.001). The endocan levels in children with bacterial pneumonia were significantly associated with the need for intensive care (P = 0.004) and correlated with the length of hospital stay (LoS) (r = 0.592, P = 0.005). Conclusion: The findings of this study indicated that serum endocan levels can be used in the differential diagnosis of bacterial and viral pneumonias. Additionally, it was found that the need for intensive care and LoS were significantly correlated with endocan levels in children with bacterial pneumonia.

Expression Patterns of Airway Fluid Cytokines From Intubated Children With Pediatric Acute Respiratory Distress Syndrome

Pediatric acute respiratory distress syndrome (PARDS) is a heterogeneous illness affecting 6% of mechanically ventilated children and with an overall mortality of 17%. Studies in PARDS have mainly focused on plasma biomarkers which may not reflect airway biomarkers. We lack adequate understanding of the inflammatory mediators and underlying immune responses in the airways of PARDS patients. Our objective was to compare the levels of cytokines in the airway fluid of intubated children with severe versus nonsevere acute respiratory distress syndrome.

DESIGN

Prospective observational cohort study.

SETTING

Single 36-bed quaternary care academic safety-net hospital PICU.

PATIENTS

Children intubated for acute respiratory failure between January 2018 and November 2021 stratified by Pediatric Acute Lung Injury Consensus Conference-1 criteria for PARDS.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured levels of 23 cytokines, chemokines, and protein biomarkers in the tracheal aspirate from 82 intubated children, between 14 days and 17 years old, at risk for or with PARDS. Levels of interleukin-4, -5, -7, -8, -12(p-70), -17a, -21, and fractalkine were higher in patients with severe versus nonsevere PARDS. There were no associations between airway and plasma cytokines.

CONCLUSIONS

Proinflammatory cytokines are elevated in the airway fluid from intubated children with severe PARDS and reflect diverse patterns of airway inflammation.

Dynamic Monitoring of Serum Protein in Acute Respiratory Distress Syndrome Based on Artificial Neural Network

Acute respiratory distress syndrome (ARDS) is one of the more serious diseases in human lung disease. Reducing its incidence rate is an important task in current clinical research. Dynamic monitoring of serum protein in patients will help to achieve the early diagnosis and treatment of ARDS. In this study, a protein monitoring model based on artificial neural network is proposed. First, surface enhanced laser desorption ionization time-of-flight mass spectrometry is used for protein detection, and then BP neural network is used for protein classification and content analysis. In the experimental analysis, serum samples from patients with acute respiratory distress syndrome in our hospital from November 2020 to August 2021 were selected for experimental testing. The experimental results show that the serum protein monitoring model based on BP neural network has low error and high convergence ability and can monitor individual protein in protein monitoring, and the area under the ROC curve in diagnostic performance reaches 0.854. The above results show that the artificial neural network has a good effect on the dynamic monitoring of serum protein in acute respiratory distress syndrome, and the diagnostic performance evaluation can reach 0.854, which has the ability to significantly improve the clinical diagnosis and treatment of acute respiratory distress syndrome.

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.

Evolution of multiple omics approaches to define pathophysiology of pediatric acute respiratory distress syndrome

Pediatric acute respiratory distress syndrome (PARDS), though both common and deadly in critically ill children, lacks targeted therapies. The development of effective pharmacotherapies has been limited, in part, by lack of clarity about the pathobiology of pediatric ARDS. Epithelial lung injury, vascular endothelial activation, and systemic immune activation are putative drivers of this complex disease process. Prior studies have used either hypothesis-driven (e.g., candidate genes and proteins, in vitro investigations) or unbiased (e.g., genome-wide association, transcriptomic, metabolomic) approaches to predict clinical outcomes and to define subphenotypes. Advances in multiple omics technologies, including genomics, transcriptomics, proteomics, and metabolomics, have permitted more comprehensive investigation of PARDS pathobiology. However, omics studies have been limited in children compared to adults, and analyses across multiple tissue types are lacking. Here, we synthesized existing literature on the molecular mechanism of PARDS, summarized our interrogation of publicly available genomic databases to determine the association of candidate genes with PARDS phenotypes across multiple tissues and cell types, and integrated recent studies that used single-cell RNA sequencing (scRNA-seq). We conclude that novel profiling methods such as scRNA-seq, which permits more comprehensive, unbiased evaluation of pathophysiological mechanisms across tissue and cell types, should be employed to investigate the molecular mechanisms of PRDS toward the goal of identifying targeted therapies.

Biomarkers of Glycocalyx Injury and Endothelial Activation are Associated with Clinical Outcomes in Patients with Sepsis: A Systematic Review and Meta-Analysis

OBJECTIVE

Sepsis is one of the main causes of morbidity and mortality worldwide. Microcirculatory impairment, especially damage to the endothelium and glycocalyx, is often not assessed. The objective of this systematic review and meta-analysis was to summarize the available evidence of the risk of unsatisfactory outcomes in patients with sepsis and elevated glycocalyx injury and endothelial activation biomarkers.

DESIGN

A systematic search was carried out on PubMed/MEDLINE, Embase, Cochrane and Google Scholar up to December 31, 2021, including studies in adults and children with sepsis which measured glycocalyx injury and endothelial activation biomarkers within 48 hours of hospital admission. The primary outcome was the risk of mortality from all causes and the secondary outcomes were the risk of developing respiratory failure (RF) and multiple organ dysfunction syndrome (MODS) in patients with elevations of these biomarkers.

MEASUREMENTS AND MAIN RESULTS

A total of 17 studies (3,529 patients) were included: 11 evaluated syndecan-1 (n=2,397) and 6 endocan (n=1,132). Syndecan-1 was higher in the group of patients who died than in those who survived [255 ng/mL (IQR: 139-305) vs. 83 ng/mL (IQR:40-111); p=0.014]. Patients with elevated syndecan-1 had a greater risk of death (OR 2.32; 95% CI 1.89, 3.10: p<0.001), MODS (OR 3.3; 95% CI 1.51, 7.25: p=0.003;), or RF (OR 7.53; 95% CI 1.86-30.45: p=0.005). Endocan was higher in patients who died [3.1 ng/mL (IQR 2.3, 3.7) vs. 1.62 ng/mL (IQR 1.2, 5.7); OR 9.53; 95% CI 3.34, 27.3; p<0.001], who had MODS (OR 8.33; 95% CI 2.07, 33.58; p=0.003) and who had RF (OR 9.66; 95% CI 2.26, 43.95; p=0.002).

CONCLUSION

Patients with sepsis and abnormal glycocalyx injury and endothelial activation biomarkers have a greater risk of developing respiratory failure, multiple organ failure, and death. Microcirculatory impairment should be routinely evaluated in patients with sepsis, using biomarkers to stratify risk groups.

An analysis of the 28-day mortality risk factors in acute respiratory distress syndrome patients and the establishment of prediction models

OBJECTIVE

To explore the risk factors and prediction models of 28-day mortality in acute respiratory distress syndrome (ARDS) patients.

METHODS

A total of 215 ARDS patients treated in our hospital were enrolled in this prospective observational study, including 70 patients who died within 28 days and were placed in the death group, and the remaining 145 patients who survived and were placed in the survival group. The laboratory examination indexes and critical scoring system scores were compared between the two groups. A Cox regression analysis was used to analyze the factors associated with 28-day mortality, and a receiver operating characteristic (ROC) curve was used to analyze the performance of the prediction models.

RESULTS

The ROC curve analysis showed that the erythrocyte distribution width (RDW), the neutrophil to lymphocyte ratio (NLR), the procalcitonin to albumin ratio (PAR), and the Murray lung injury score (MLIS) were effective at diagnosing the 28-day mortality, each with an area under the curve (AUC) of >0.5 (P<0.001). A multivariate Cox analysis showed that the RDW, NLR, PAR, and MLIS were independent predictors of 28-day mortality. The results of the multi-index joint prediction showed that the AUC of RDW+NLR+PAR+MLIS was 0.945 (95% CI: 0.910-0.979), and the sensitivity was as high as 94.25%.

CONCLUSION

NLR, PAR, RDW, and MLIS are independent predictors of 28-day mortality, and their combined prediction can significantly improve the predictive ability of the 28-day mortality in ARDS patients.

Endothelial Dysfunction as a Component of Severe Acute Respiratory Syndrome Coronavirus 2-Related Multisystem Inflammatory Syndrome in Children With Shock

Supplemental Digital Content is available in the text.

NCT04420468.

Salidroside protects endothelial cells against LPS-induced inflammatory injury by inhibiting NLRP3 and enhancing autophagy

BACKGROUND

Salidroside (SAL) is a bioactive compound extracted from Rhodiola rosea with various biological properties. This study was designed to explore the functions of SAL on the endothelial damage induced by lipopolysaccharide (LPS) and its related mechanisms.

METHODS

Human umbilical vein endothelial cells (HUVECs) were pretreated with SAL (0, 10, 25, 50, 100 μM), and then incubated with LPS (10 μg/mL). Cell viability was evaluated by MTT assay, cell injury by lactate dehydrogenase (LDH) release, and inflammatory cytokines release by ELISA assay. Oxidative stress was evaluated by malondialdehyde (MDA) and superoxide dismutase (SOD) in cell lysate. Apoptosis was detected by flow cytometry and caspase-3 activity. Western blot were performed to determine expression levels of autophagy and NOD-like receptor protein 3 (NLRP3) related proteins.

RESULTS

SAL at 50 μM concentration showed no toxicity on HUVECs, but attenuated LPS-induced injury, as evidenced by increased cell viability, reduction in LDH level and inflammatory cytokines in culture media. SAL also reduced MDA level and increased SOD activity in HUVECs, and inhibited apoptosis rate and caspase-3 activity. (P < 0.05). Moreover, LPS enhanced HUVECs autophagy, and SAL pretreatment further enhanced autophagy, with increased Beclin-1 protein and decreased P62 protein. SAL also attenuated LPS-induced activation of NLRP3 inflammasome, reduced the protein expression of NLRP3-related proteins, including ASC and caspase-1. Autophagy inhibition by 3-MA markedly reversed SAL-modulated changes in cell viability and NLRP3 expression in LPS-stimulated HUVECs.

CONCLUSION

SAL protects endothelial cells against LPS-induced injury through inhibition of NLRP3 pathways and enhancing autophagy.

Diagnostic biomarkers to differentiate sepsis from cytokine release syndrome in critically ill children

Chimeric antigen receptor (CAR) T-cells directed against CD19 have drastically altered outcomes for children with relapsed and refractory acute lymphoblastic leukemia (r/r ALL). Pediatric patients with r/r ALL treated with CAR-T are at increased risk of both cytokine release syndrome (CRS) and sepsis. We sought to investigate the biologic differences between CRS and sepsis and to develop predictive models which could accurately differentiate CRS from sepsis at the time of critical illness. We identified 23 different cytokines that were significantly different between patients with sepsis and CRS. Using elastic net prediction modeling and tree classification, we identified cytokines that were able to classify subjects as having CRS or sepsis accurately. A markedly elevated interferon γ (IFNγ) or a mildly elevated IFNγ in combination with a low IL1β were associated with CRS. A normal to mildly elevated IFNγ in combination with an elevated IL1β was associated with sepsis. This combination of IFNγ and IL1β was able to categorize subjects as having CRS or sepsis with 97% accuracy. As CAR-T therapies become more common, these data provide important novel information to better manage potential associated toxicities.

Endothelial Biomarkers Are Associated With Indirect Lung Injury in Sepsis-Associated Pediatric Acute Respiratory Distress Syndrome

Supplemental Digital Content is available in the text.

Objectives:

Acute respiratory distress syndrome occurring in the setting of direct versus indirect lung injury may reflect different pathobiologies amenable to different treatment strategies. We sought to test whether a panel of plasma biomarkers differed between children with sepsis-associated direct versus indirect acute respiratory distress syndrome. We hypothesized that a biomarker profile indicative of endothelial activation would be associated with indirect acute respiratory distress syndrome.

Design:

Observational cohort.

Setting:

Academic PICU.

Subjects:

Patients less than 18 years old with sepsis-associated direct (pneumonia, n = 52) or indirect (extrapulmonary sepsis, n = 46) acute respiratory distress syndrome.

Interventions:

None.

Measurements and Main Results:

Of 58 biomarkers examined, 33 differed by acute respiratory distress syndrome subtype. We used classification and regression tree methodology to examine associations between clinical and biochemical markers and acute respiratory distress syndrome subtype. The classification and regression tree model using only clinical variables (age, sex, race, oncologic comorbidity, and Pediatric Risk of Mortality-III score) performed worse than the classification and regression tree model using five clinical variables and 58 biomarkers. The best classification and regression tree model used only four endothelial biomarkers, including elevated angiopoietin-2/angiopoietin-1 ratio, vascular cell-adhesion molecule, and von Willebrand factor, to identify indirect acute respiratory distress syndrome. Test characteristics were 89% (80–97%) sensitivity, 80% (69–92%) specificity, positive predictive value 84% (74–93%), and negative predictive value 86% (76–96%).

Conclusions:

Indirect lung injury in children with acute respiratory distress syndrome is characterized by a biomarker profile indicative of endothelial activation, excess inflammation, and worse outcomes. A model using four biomarkers has the potential to be useful for more precisely identifying patients with acute respiratory distress syndrome whose pathobiology may respond to endothelial-targeted therapies in future trials.

Understanding the role of neutrophils in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is difficult to treat and is associated with a high mortality rate. The most severe form of coronavirus disease 2019 (COVID-19) also leads to life-threatening ARDS. Neutrophil counts are positively correlated with disease severity in ARDS. Neutrophil activation not only plays a significant role in immune defense against infections, but also causes tissue damage and leads to inflammatory diseases. Activated neutrophils rapidly migrate to inflamed lung tissue, releasing toxic granular contents and generating neutrophil extracellular traps. In the last few decades, it has become apparent that neutrophils occupy a central role in ARDS pathology. In this review, we summarize the neutrophil inflammatory responses and their relationships to ARDS. According to the current literature, understanding the function of neutrophils may be helpful in the treatment of ARDS.

Targeting the Immune System for Pulmonary Inflammation and Cardiovascular Complications in COVID-19 Patients

In December 2019, following a cluster of pneumonia cases in China caused by a novel coronavirus (CoV), named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the infection disseminated worldwide and, on March 11th, 2020, the World Health Organization officially declared the pandemic of the relevant disease named coronavirus disease 2019 (COVID-19). In Europe, Italy was the first country facing a true health policy emergency, and, as at 6.00 p.m. on May 2nd, 2020, there have been more than 209,300 confirmed cases of COVID-19. Due to the increasing number of patients experiencing a severe outcome, global scientific efforts are ongoing to find the most appropriate treatment. The usefulness of specific anti-rheumatic drugs came out as a promising treatment option together with antiviral drugs, anticoagulants, and symptomatic and respiratory support. For this reason, we feel a duty to share our experience and our knowledge on the use of these drugs in the immune-rheumatologic field, providing in this review the rationale for their use in the COVID-19 pandemic.

Childhood Obesity, Endothelial Cell Activation, and Critical Illness

Pediatric obesity is increasing in prevalence and is frequently an antecedent to adult obesity and adult obesity-associated morbidities such as atherosclerosis, type II diabetes, and chronic metabolic syndrome. Endothelial cell activation, one aspect of inflammation, is present in the early stages of atherosclerosis, often prior to the onset of symptoms. Endothelial activation is a pathological condition in which vasoconstricting, pro-thrombotic, and proliferative mediators predominate protective vasodilating, anti-thrombogenic, and anti-mitogenic mediators. Many studies report poor outcomes among obese children with systemic endothelial activation. Likewise, the link between childhood obesity and poor outcomes in critical illness is well-established. However, the link between obesity and severity of endothelial activation specifically in the setting of critical illness is largely unstudied. Although endothelial cell activation is believed to worsen disease in critically ill children, the nature and extent of this response is poorly understood due to the difficulty in measuring endothelial cell dysfunction and destruction. Based on the data available for the obese, asymptomatic population and the obese, critically ill population, the authors posit that obesity, and obesity-associated chronic inflammation, including oxidative stress and insulin resistance, may contribute to endothelial activation and associated worse outcomes among critically ill children. A research agenda to examine this hypothesis is suggested.