Biomarkers In Acute Respiratory Distress Syndrome Research Articles

Dysregulated Coagulation and Fibrinolysis Are Present in Patients Admitted to the Emergency Department with Acute Hypoxemic Respiratory Failure: A Prospective Study.

Acute hypoxemic respiratory failure (AHRF) is defined as acute and progressive, and patients are at a greater risk of developing acute respiratory distress syndrome (ARDS). Until now, most studies have focused on prognostic and diagnostic biomarkers in ARDS. Since there is evidence supporting a connection between dysregulated coagulant and fibrinolytic pathways in ARDS progression, it is plausible that this dysregulation also exists in AHRF. The aim of this study was to explore whether levels of soluble endothelial protein C receptor (sEPCR) and plasminogen differentiate patients admitted to the emergency department (ED) with AHRF. sEPCR and plasminogen levels were measured in 130 AHRF patients upon ED presentation by ELISA. Our results demonstrated that patients presenting to the ED with AHRF had elevated levels of sEPCR and plasminogen. It seems that dysregulation of coagulation and fibrinolysis occur in the early stages of respiratory failure requiring hospitalisation. Further research is needed to fully comprehend the contribution of sEPCR and plasminogen in AHRF.

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

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. Secondary unplanned post hoc analysis of data from a prospective observational cohort study carried out 2014-2019. University-affiliated PICU. Mechanically ventilated children with ARDS. None. 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). 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.

ARDS and aging: TYMS emerges as a promising biomarker and therapeutic target.

Acute Respiratory Distress Syndrome (ARDS) is a common condition in the intensive care unit (ICU) with a high mortality rate, yet the diagnosis rate remains low. Recent studies have increasingly highlighted the role of aging in the occurrence and progression of ARDS. This study is committed to investigating the pathogenic mechanisms of cellular and genetic changes in elderly ARDS patients, providing theoretical support for the precise treatment of ARDS. Gene expression profiles for control and ARDS samples were obtained from the Gene Expression Omnibus (GEO) database, while aging-related genes (ARGs) were sourced from the Human Aging Genomic Resources (HAGR) database. Differentially expressed genes (DEGs) were subjected to functional enrichment analysis to understand their roles in ARDS and aging. The Weighted Gene Co-expression Network Analysis (WGCNA) and machine learning pinpointed key modules and marker genes, with ROC curves illustrating their significance. The expression of four ARDS-ARDEGs was validated in lung samples from aged mice with ARDS using qRT-PCR. Gene set enrichment analysis (GSEA) investigated the signaling pathways and immune cell infiltration associated with TYMS expression. Single-nucleus RNA sequencing (snRNA-Seq) explored gene-level differences among cells to investigate intercellular communication during ARDS onset and progression. ARDEGs are involved in cellular responses to DNA damage stimuli, inflammatory reactions, and cellular senescence pathways. The MEmagenta module exhibited a significant correlation with elderly ARDS patients. The LASSO, RRF, and XGBoost algorithms were employed to screen for signature genes, including CKAP2, P2RY14, RBP2, and TYMS. Further validation emphasized the potential role of TYMS in the onset and progression of ARDS. Immune cell infiltration indicated differential proportion and correlations with TYMS expression. SnRNA-Seq and cell-cell communication analysis revealed that TYMS is highly expressed in endothelial cells, and the SEMA3 signaling pathway primarily mediates cell communication between endothelial cells and other cells. Endothelial cell damage associated with aging could contribute to ARDS progression by triggering inflammation. TYMS emerges as a promising diagnostic biomarker and potential therapeutic target for ARDS.

Prone Positioning and Molecular Biomarkers in COVID and Non-COVID ARDS: A Narrative Review.

Prone positioning (PP) represents a therapeutic intervention with the proven capacity of ameliorating gas exchanges and ventilatory mechanics indicated in acute respiratory distress syndrome (ARDS). When PP is selectively applied to moderate-severe cases of ARDS, it sensitively affects clinical outcomes, including mortality. After the COVID-19 outbreak, clinical application of PP peaked worldwide and was applied in 60% of treated cases, according to large reports. Research on this topic has revealed many physiological underpinnings of PP, focusing on regional ventilation redistribution and the reduction of parenchymal stress and strain. However, there is a lack of evidence on biomarkers behavior in different phases and phenotypes of ARDS. Patients response to PP are, to date, decided on PaO2/FiO2 ratio improvement, whereas scarce data exist on biomarker tracking during PP. The purpose of this review is to explore current evidence on the clinical relevance of biomarkers in the setting of moderate-severe ARDS of different etiologies (i.e., COVID and non-COVID-related ARDS). Moreover, this review focuses on how PP may modulate biomarkers and which biomarkers may have a role in outcome prediction in ARDS patients.

Diagnostic and Predictive Significance of Serum MiR-141-3p in Acute Respiratory Distress Syndrome Patients with Pulmonary Fibrosis.

Pulmonary fibrosis (PF) is the major complication and death-related factor of acute respiratory distress syndrome (ARDS). This study evaluated the significance of miR-141-3p in ARDS and its complication of PF aiming to identify a potential biomarker for screening ARDS and predicting the occurrence of PF. A total of 137 ARDS patients and 69 healthy individuals were enrolled in this study and the serum samples were collected from all participants. The serum miR-141-3p levels were analyzed by polymerase chain reaction. The significance of miR-141-3p in the diagnosis and development of ARDS, and the occurrence of PF was evaluated by receiver operating curve, Chi-square test, and logistic regression analysis. MiR-141-3p was downregulated in ARDS patients and showed significant potential in its diagnosis. Reduced miR-141-3p was significantly associated with the increasing Murray and APACHEII score and the occurrence of PF in ARDS patients. MiR-141-3p, Murray score, and APACHEII score were identified as risk factors for the occurrence of PF in ARDS, and miR-141-3p was also found to be downregulated in ARDS patients with PF. Additionally, miR-141-3p could discriminate ARDS patients with PF and without PF, and was closely associated with the decreased total lung capacity, carbon monoxide diffusing capacity, and forced vital capacity of ARDS patients with PF. Downregulated miR-141-3p served as a biomarker for ARDS screening disease onset and indicating the severity. Reduced miR-141-3p was also identified as a risk factor for PF in ARDS patients and was associated with the severe progression of PF.

Elevated ferritin, mediated by IL-18 is associated with systemic inflammation and mortality in acute respiratory distress syndrome (ARDS)

BackgroundInflammatory subphenotypes have been identified in acute respiratory distress syndrome (ARDS). Hyperferritinaemia in sepsis is associated with hyperinflammation, worse clinical outcomes, and may predict benefit with immunomodulation. Our aim was...

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 72h 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 6h 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.

Cytokine response and damages in the lungs of aging Syrian hamsters on a high-fat diet infected with the SARS-CoV-2 virus.

Hypertriglyceridemia, obesity, and aging are among the key risk factors for severe COVID-19 with acute respiratory distress syndrome (ARDS). One of the main prognostic biomarkers of ARDS is the level of cytokines IL-6 and TNF-α in the blood. In our study, we modeled hyperglyceridemia and hypercholesterolemia on 18-month-old Syrian hamsters (Mesocricetus auratus). By 18 months, the animals showed such markers of aging as weight stabilization with a tendency to reduce it, polycystic liver disease, decreased motor activity, and foci of alopecia. The high-fat diet caused an increase in triglycerides and cholesterol, as well as fatty changes in the liver. On the third day after infection with the SARS-CoV-2 virus, animals showed a decrease in weight in the groups with a high-fat diet. In the lungs of males on both diets, there was an increase in the concentration of IFN-α, as well as IL-6 in both males and females, regardless of the type of diet. At the same time, the levels of TNF-α and IFN-γ did not change in infected animals. Morphological studies of the lungs of hamsters with SARS-CoV-2 showed the presence of a pathological process characteristic of ARDS. These included bronchointerstitial pneumonia and diffuse alveolar damages. These observations suggest that in aging hamsters, the immune response to pro-inflammatory cytokines may be delayed to a later period. Hypertriglyceridemia, age, and gender affect the severity of COVID-19. These results will help to understand the pathogenesis of COVID-19 associated with age, gender, and disorders of fat metabolism in humans.

Identification of Genes as Potential Biomarkers for Sepsis-related ARDS using Weighted Gene Co-expression Network Analysis.

Acute respiratory distress syndrome (ARDS) caused by sepsis presents a high mortality rate; therefore, identification of susceptibility genes of sepsis to ARDS at an early stage is particularly critical. The GSE66890 dataset was downloaded and analyzed by WGCNA to obtain modules. Then, GO and KEGG analyses of the module genes were performed. Then, the PPI network and LASSO model were constructed to identify the key genes. Finally, expression levels of the screened genes were validated in clinical subjects. We obtained 17 genes merged modules via WGCNA, and the dark module and tan module were the most positively and negatively correlated with sepsis-induced ARDS, respectively. Based on gene intersections of the module genes, 11 hub genes were identified in the dark module, and 5 hub genes were identified in the tan module. Finally, the six key genes were identified by constructing the LASSO model. We further detected the screened genes expression in clinical samples, and as the bioinformatics analysis revealed, the expressions of NANOG, RAC1, TWIST1, and SNW1 were significantly upregulated in the ARDS group compared to the sepsis group, and IMP3 and TUBB4B were significantly downregulated. We identified six genes as the potential biomarkers in sepsis-related ARDS. Our findings may enhance the knowledge of the molecular mechanisms behind the development of sepsisinduced ARDS.

Circulating Pulmonary-Originated Epithelial Biomarkers for Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis.

Previous studies have found several biomarkers for acute respiratory distress syndrome (ARDS), but the accuracy of most biomarkers is still in doubt due to the occurrence of other comorbidities. In this systematic review and meta-analysis, we aimed to explore ideal ARDS biomarkers which can reflect pathophysiology features precisely and better identify at-risk patients and predict mortality. Web of Science, PubMed, Embase, OVID, and the Cochrane Library were systematically searched for studies assessing the reliability of pulmonary-originated epithelial proteins in ARDS. A total of 32 studies appeared eligible for meta-analysis, including 2654 ARDS/ALI patients in this study. In the at-risk patients' identification group, the highest pooled effect size was observed in Krebs von den Lungren-6 (KL-6) (SMD: 1.17 [95% CI: 0.55, 1.79]), followed by club cell proteins 16 (CC16) (SMD: 0.74 [95% CI: 0.01, 1.46]), and surfactant proteins-D (SP-D) (SMD: 0.71 [95% CI: 0.57, 0.84]). For the mortality prediction group, CC16 exhibited the largest effect size with SMD of 0.92 (95% CI: 0.42, 1.43). Meanwhile, the summary receiver operating characteristic (SROC) of CC16 for ARDS diagnosis reached an AUC of 0.80 (95% CI: 0.76, 0.83). In conclusion, this study provides a ranking system for pulmonary-originated epithelial biomarkers according to their association with distinguishing at-risk patients and predicting mortality. In addition, the study provides evidence for the advantage of biomarkers over traditional diagnostic criteria. The performance of biomarkers may help to clinically improve the ARDS diagnosis and mortality prediction.

Expression and role of deleted in malignant brain tumor protein 1 in acute respiratory distress syndrome rats induced by sepsis

To observe the expression of deleted in malignant brain tumor protein 1 (DMBT1) in rat acute respiratory distress syndrome (ARDS) model induced by sepsis and its relationship with ARDS related biomarkers. Forty-eight healthy male rats were randomly divided into sham operation group (Sham group) and ARDS model group, and the rats in each group were further divided into three subgroups at 6, 12 and 24 hours after operation, with 8 rats in each subgroup. The rats in the Sham group were exposed to the cecum only, and sepsis induced ARDS model was reproduced by cecal ligation and puncture (CLP) in the ARDS model group. The general performance was observed at 6, 12, 24 hours after operation. Abdominal aortic blood of rats was collected, and the levels of DMBT1, surfactant-associated protein D (SP-D), vascular endothelial growth factor (VEGF), interleukins (IL-6, IL-10) in serum were determined by enzyme-linked immunosorbent assay (ELISA). The lung tissues were collected, and the lung wet/dry weight (W/D) ratio was determined. The lung tissue pathological changes were observed under light microscope after hematoxylin-eosin (HE) staining, and the lung tissue injury score was evaluated. The expression of DMBT1 protein in lung tissue was determined by Western blotting. The relationship between the serum DMBT1 and SP-D, VEGF, IL-6, IL-10, lung tissue injury score were analyzed by Pearson correlation analysis. Rats in the ARDS model group showed obvious pathological manifestations after operation. The alveolar structure destruction, inflammatory cell infiltration, and alveolar hemorrhage were observed under microscope. Compared with the Sham group, the lung tissue injury score and the lung W/D ratio at 12 hours after operation in the ARDS model group were significantly increased (lung tissue injury score: 3.35±0.13 vs. 1.16±0.07, lung W/D ratio: 5.36±0.44 vs. 4.38±0.35, both P < 0.05), and pulmonary edema was present, which suggested that the ARDS model caused by CLP was successfully reproduced. The results of ELISA and Western blotting showed that the levels of serum DMBT1, SP-D, VEGF and IL-6 in the ARDS model group increased gradually with time, while the level of IL-10 increased first and then decreased. Compared with the Sham group, the levels of DMBT1 in serum and the expressions of DMBT1 protein in lung tissue in the ARDS model group were significantly increased from 6 hours after operation [serum (ng/L) : 231.96±19.17 vs. 187.44±10.19, lung tissue (DMBT1/β-actin): 2.05±0.19 vs. 0.93±0.25, both P < 0.05], and the levels of SP-D, VEGF, IL-6 and IL-10 in serum were significantly increased from 12 hours after operation [SP-D (ng/L): 73.35±8.05 vs. 43.28±5.77, VEGF (ng/L): 89.85±8.47 vs. 43.19±5.11, IL-6 (ng/L): 36.01±2.48 vs. 17.49±1.77, IL-10 (ng/L): 84.55±8.41 vs. 39.83±5.02, all P < 0.05]. Pearson correlation analysis showed that serum DMBT1 was positively correlated with serum SP-D, VEGF, IL-6, IL-10 and lung injury score at 12 hours and 24 hours in the ARDS model group (12 hours: r values were 0.946, 0.942, 0.931, 0.936, 0.748, respectively; 24 hours: r values were 0.892, 0.945, 0.951, 0.918, 0.973, respectively; all P < 0.05). DMBT1 is a novel early biomarker of ARDS by affecting alveolar epithelial cell, alveolar capillary permeability and inflammatory response.

Screening study of peripheral blood biomarkers in sepsis-associated ARDS

Objective: Acute respiratory distress syndrome (ARDS) is a serious and rapidly progressive complication of sepsis with a very high mortality rate. Screening for reliable biomarkers can assist in the diagnosis and treatment of the disease, and the development of personalized immunotherapy regimens may provide great clinical benefit. Method: The clinical data of 110 patients with sepsis treated in our medical unit from November 2018 to January 2020 were reviewed through a single-center retrospective analytic study. Using the Statistical Package for Social Science (SPSS, version 26) and the software GraphPad Prism 7, statistical analyses were performed and graphs were generated. Mean (standard deviation [SD]) and median (interquartile range [IQR]) should be used for description of normally and non-normally distributed data, respectively. The normal and non-normal distributed quantitative variables were respectively assessed by independent T-test or Chi-square test. P-value <0. 05 noted statistical significance. Results: (1) Finally, 32 patients were enrolled in the study, among 32 patients with sepsis-associated ARDS, there were 13 cases in the survival group and 19 cases in the death group. There were 10 males and 3 females in the survival group, with an age of 61. 77±14. 296 years. There were 13 males and 6 females in the death group, with an age of 66. 11±11. 455 years. There was no statistically significant difference between the two groups in terms of age and gender (P>0. 05). (2) The difference in PaO2/FiO2 between the two groups was statistically significant (P<0. 05). Their AUC was 0. 8057, and the sensitivity and specificity were 89. 47% and 69. 23% respectively. (3) By comparison of median scatter plots, cytokines IL-6, IL-6/IL-10, admission NLR, and discharge NLR were higher in the death group compared with survival. IL-10 and IFN-γ were lower compared with survival. (4) The results of logistic regression analysis showed risk factors affecting the prognosis of sepsis-associated ARDS:PaO2/FiO2 (P=0. 019, OR:12. 289, 95% CI:1. 512 - 99. 8);Protective factor: IFN-γ(P=0. 03, OR:0. 161, 95% CI:0. 031 - 0. 834 ). Conclusion: (1) PaO2/FiO2 can be used to assess the prognosis of septic ARDS patients; (2) cytokine assay may be a guide to determine the prognosis of septic ARDS; (3) IFN-γmay be a protective factor in the course of septic ARDS patients.

Microarray profiling of circular RNAs in LPS-induced Beas-2B cells and identification of circ_2979 as a potential biomarker for ARDS

Acute respiratory distress syndrome (ARDS) is a major cause of high mortality and morbidity in critically ill patients. Circular RNAs (CircRNAs) are widely expressed in numerous tissues and are associated with various diseases. However, the role of circRNAs in ARDS remains unclear. In this study, we found that cell viability and proliferation were reduced in lipopolysaccharide (LPS)-induced Beas-2B cells. Microarray analysis identified 1131 differentially expressed circRNAs in LPS-treated Beas-2B cells, with 623 circRNAs significantly upregulated and 508 circRNAs strongly downregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed significant enrichment and indicated potential functions and pathways of differentially expressed circRNAs. Reverse transcription-polymerase chain reaction (RT-PCR) analysis confirmed that expression of circ_2979, circ_5438, circ_4557 and circ_2066 in LPS-induced Beas-2B cells was consistent with the results obtained by RNA sequencing (RNA-seq). Additionally, we recruited 17 patients with ARDS and 13 healthy volunteers and found that expression of circ_2979 in serum was significantly increased in the patients with ARDS compared with healthy volunteers. Spearman's analyses indicated that circ_2979 was correlated with partial pressure of carbon dioxide in arterial blood (PaCO2), the ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2), interleukin 2 receptor (IL-2R) and fibrinogen (FIB). The results suggested that circRNAs may play an important role in the progression of ARDS, and that circ_2979 may serve as a diagnosis and prognosis biomarker for ARDS.

Research Progress on Phenotypic Classification of Acute Respiratory Distress Syndrome: A Narrative Review.

Acute respiratory distress syndrome (ARDS) is a clinical syndrome that is characterized by an acute onset and refractory hypoxemia. It remains an important contributor to high mortality in critically ill patients, and the majority of clinical randomized controlled trials on ARDS provide underwhelming findings, which is attributed in large part to its pathophysiological and clinical heterogeneity, among other aspects. It is now widely accepted that ARDS is highly heterogeneous, growing evidences support this. ARDS phenotypic and subphenotypic studies aim to further differentiate and identify ARDS heterogeneity in the hope that clinicians can benefit from it, then can diagnose ARDS faster and more accurately and provide targeted treatments. This review collates and evaluates the major phenotype-related research advances of recent years, with a specific focus on ARDS biomarkers and clinical factors.

CircUBXN7 suppresses cell proliferation and facilitates cell apoptosis in lipopolysaccharide-induced cell injury by sponging miR-622 and regulating the IL6ST/JAK1/STAT3 axis.

Acute respiratory distress syndrome (ARDS) is a common and serious respiratory illness with substantial morbidity and mortality. Circular RNAs have been demonstrated to participate in various diseases processes. However, the biological function and mechanism of most circular RNAs have not been elucidated in ARDS. In this study, we found that circUBXN7 was significantly increased in lipopolysaccharide (LPS)-induced A549 and Beas-2B cell injury. Inhibition of circUBXN7 significantly promoted cell proliferation and reduced cell apoptosis, while overexpression of circUBXN7 suppressed cell proliferation and accelerated cell apoptosis in LPS-induced A549 and Beas-2B cells. CircUBXN7 acted as a sponge for miR-622, and miR-622 rescued the effect of circUBXN7 on cell proliferation and apoptosis. We also found that IL6ST was a target gene of miR-622, and the expression of IL6ST was indirectly regulated by circUBXN7. Furthermore, western blotting indicated that the JAK1/STAT3 signaling pathway was involved in the circUBXN7/miR-622/IL6ST axis in LPS-induced A549 and Beas-2B cell injury. Overall, our study suggested that circUBXN7 suppressed cell proliferation and facilitated cell apoptosis by sponging miR-622 and regulating IL6ST, to activate the JAK1/STAT3 signaling pathway in LPS-induced A549 and Beas-2B cell injury. CircUBXN7 might therefore be a potential biomarker for ARDS, and dysregulation of circUBXN7 may be involved in the pathogenesis of ARDS.

Identification of circulating microvesicle-encapsulated miR-223 as a potential novel biomarker for ARDS.

Acute respiratory distress syndrome (ARDS) is a lethal disease with severe forms conferring a mortality rate approaching 40%. The initial phase of ARDS results in acute lung injury (ALI) characterized by a severe inflammatory response and exudative alveolar flooding due to pulmonary capillary leak. Timely therapies to reduce ARDS mortality are limited by the lack of laboratory-guided diagnostic biomarkers for ARDS. The purpose of this study was to evaluate the prognostic role of circulating microvesicles (MVs)-containing miR-223 (MV-miR-223) if indicate more severe lung injury and worse outcomes in ARDS patients. Human plasma samples from one hundred ARDS patients enrolled in Albuterol to Treat Acute Lung Injury (ALTA) trial were compared to a control group of twenty normal human plasma specimens. The amount of MV-miR-223 was measured using absolute real-time polymerase chain reaction (PCR) with a standard curve. Mann-Whitney-Wilcoxon, Spearman correlation, Chi-squared tests, and Kaplan-Meier curves were computed to assess different variables and survival. Plasma levels of MV-miR-223 were significantly higher in ARDS patients compared to normal control subjects. Upon receiver operator characteristic (ROC) analysis of MV-miR-223 in relation to 30-day mortality, MV-miR-223 had an area under the curve (AUC) of 0.7021 with an optimal cut-off value of 2.413 pg/ml. Patients with high MV-miR-223 had higher 30-day mortality than subjects with low MV-miR-223 levels. MV-miR-223 was negatively correlated with ICU-free days, ventilator-free days, and organ failure-free days. Patients with high MV-miR-223 levels had higher 30 and 90-day mortality. MV-miR-223 was associated with 28-day clinical outcomes of ALTA trial including ICU-free days, ventilator-free days, and organ failure-free days. Thus, circulating MV-miR-223 may be a potential biomarker in prognosticating patient-centered outcomes and predicting mortality in ARDS.

Research progress on the role of endothelial cell-specific molecular-1 in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS), a common respiratory critical illness with multiple causes, is associated with high mortality. The high degree of heterogeneity may be the reason why it is lack of highly specific and sensitive biological biomarkers. Therefore, it is an urgent need to explore biomarkers, perform phenotypic analysis and establish risk stratification model for diagnosis, prognosis, and treatment of ARDS. Endothelial cells specificity molecular-1 (ESM-1, endocan), is a soluble dermatan sulfate proteoglycan, and be involved in regulating biological behaviors such as cell proliferation, differentiation and migration. Numerous studies have confirmed that ESM-1 is closely related to inflammation, endothelial activation and dysfunction. However, the role of ESM-1 in the initiating and developing process of ARDS is still unclear. To provide a scientific basis for its clinical applications in ARDS, such as early prognosis assessment and timely prevent strategies, this paper focuses on the biological properties and the clinical value of ESM-1 as a potential biomarker for ARDS.

Serum human epididymis secretory protein 4 correlates with sepsis-associated acute respiratory distress syndrome and 28-day mortality in critically ill patients.

Acute respiratory distress syndrome (ARDS) is a severe disease with high mortality, and its primary cause is sepsis. The aim of this study was to detect and evaluate the role of Human epididymis protein 4 (HE4) in sepsis-related ARDS. One hundred and twenty-three critically ill sepsis patients with/without ARDS and 102 healthy controls were enrolled in this study. Blood samples were collected upon admission for quantitative testing of HE4 by chemiluminescent microparticle immunoassay (CMIA). ROC curve analysis and Spearman's correlation analysis were conducted to determine the diagnostic and prognostic value of HE4. Compared with controls, the serum HE4 concentrations of sepsis patients were elevated, and levels in sepsis patients with ARDS were significantly higher (all p < 0.0001). Moreover, HE4 concentrations were strongly correlated with the clinical severity characteristics of sepsis patients, and ROC curve suggested that the AUC of HE4 applied to discriminate sepsis-ARDS patients from sepsis patients was 0.903. HE4 was also found to be a prognostic biomarker of clinical severity and 28-day mortality among critically ill sepsis patients. Logistic regression analysis showed that HE4 was an independent factor for diagnosis of ARDS. Meanwhile, ROC curve analysis showed that the cut-off value of serum HE4 to discriminate 28-day mortality from sepsis patients (AUC: 0.782) was 646.5pmol/L. The concentration of serum HE4 in patients with sepsis-related ARDS was markedly increased and was significantly correlated with mortality, which suggests that serum HE4 could be a promising diagnostic and prognostic biomarker for ARDS in sepsis patients.

Breath octane and acetaldehyde as markers for acute respiratory distress syndrome in invasively ventilated patients suspected to have ventilator-associated pneumonia.

RationaleThe concentration of octane and acetaldehyde in exhaled breath has good diagnostic accuracy for acute respiratory distress syndrome (ARDS). We aimed to determine whether breath octane and acetaldehyde are able to distinguish the presence and absence of ARDS in critically ill patients suspected to have ventilator-associated pneumonia (VAP).MethodsThis is a secondary analysis of a prospective observational study into exhaled breath analysis using gas chromatography–time-of-flight mass spectrometry. Difference in the relative abundance of octane and acetaldehyde in exhaled breath was compared between patients with and without ARDS using the Mann–Whitney U-test and the association was quantified using logistic regression. The discriminative accuracy of octane and acetaldehyde, alone or in combination, was calculated using the area under the receiver operating characteristic curve (AUROCC).ResultsWe included 98 patients, of whom 32 had ARDS and 66 did not. The area under the acetaldehyde peak was higher in patients with ARDS (p=0.03), and associated with the presence of ARDS (OR 1.06 per 100 000 count change, 95% CI 1.02–1.13 per 100 000 count change; p=0.01). A combined model with octane and acetaldehyde showed a high specificity and low sensitivity (90% and 40.6%, respectively), with a low accuracy (AUROCC 0.65, 95% CI 0.53–0.78).ConclusionPatients suspected to have VAP with ARDS had a higher acetaldehyde concentration in exhaled breath than patients suspected to have VAP without ARDS. However, in this patient population, discrimination of these breath biomarkers for ARDS was poor, indicating the difficulty of translating diagnostic tests between clinical settings.

CD14-positive extracellular vesicles in bronchoalveolar lavage fluid as a new biomarker of acute respiratory distress syndrome.

Recent studies have indicated that extracellular vesicles (EVs) may play a role in the pathogenesis of acute respiratory distress syndrome (ARDS). EVs have been identified as potential biomarkers of disease severity and prognosis in other pulmonary diseases. We sought to characterize the EV phenotype within bronchoalveolar lavage (BAL) fluid of patients with ARDS, and to determine whether BAL EV could be used as a potential biomarker in ARDS. BAL was collected from patients with sepsis with and without ARDS, and from esophagectomy patients postoperatively (of whom a subset later developed ARDS during hospital admission). BAL EVs were characterized with regard to size, number, and cell of origin. Patients with sepsis-related ARDS had significantly higher numbers of CD14+/CD81+ monocyte-derived BAL EV than patients with sepsis without ARDS (P = 0.015). However, the converse was observed in esophagectomy patients who later developed ARDS (P = 0.003). Esophagectomy patients who developed ARDS also had elevated CD31+/CD63+ and CD31+/CD81+ endothelial-derived BAL EV (P ≤ 0.02) compared with esophagectomy patients who did not develop ARDS. Further studies are required to determine whether CD31+ BAL EV may be a predictive biomarker for ARDS in esophagectomy patients. CD14+/CD81+ BAL EV numbers were significantly higher in those patients with sepsis-related ARDS who died during the 30 days following intensive care unit admission (P = 0.027). Thus, CD14+/CD81+ BAL EVs are a potential biomarker for disease severity and mortality in sepsis-related ARDS. These findings provide the impetus to further elucidate the contribution of these EVs to ARDS pathogenesis.