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Objective:To evaluate the clinical value of neutrophil/lymphocyte ratio (NLR) in early prediction of the incidence of sepsis-induced organ dysfunction and 28-day mortality.Methods:A retrospective study was conducted in 815 adult patients with sepsis admitted to the department of critical care medicine of the First Affiliated Hospital of China Medical University from January 2017 to December 2019. The clinical data including age, gender and complication were collected, and the peripheral blood routine indexes at 24, 48 and 72 hours after the diagnosis of sepsis were collected, and the NLR was calculated. The primary endpoint of the study was the incidences of sepsis related acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), disseminated intravascular coagulation (DIC) and acute liver failure (ALF); the secondary endpoint was the 28-day in-hospital mortality in septic patients with organ dysfunction. Univariate and multivariate Logistic regression were used to analyze the risk factors of organ dysfunction and 28-day mortality in patients with sepsis, the receiver operating characteristic curve (ROC curve) was drawn and the area under the ROC curve (AUC) was calculated to evaluate the predictive value of NLR for organ dysfunction and 28-day mortality in patients with sepsis.Results:A total of 714 patients with sepsis were enrolled for final statistical analysis. There was no significant difference in NLR at 24, 48 and 72 hours in patients with or without organ dysfunction (such as AKI, ARDS, DIC and ALF). Logistic regression analysis showed that there was no significant difference in NLR at 24 hours with 28-day in-hospital mortality [odds ratio ( OR) = 1.006, 95% confidence interval (95% CI) was 0.994-1.019, P = 0.323]. However, NLR at 48 hours and 72 hours had a significant difference with 28-day mortality (48 hours: OR = 1.026, 95% CI was 1.013-1.040, P = 0.000; 72 hours: OR = 1.021, 95% CI was 1.005-1.037, P = 0.010), which suggested that NLR at 48 hours and 72 hours after diagnosis were independent risks factor for 28-day mortality in patients with sepsis. ROC curve showed that the AUC of NLR at 48 hours was 0.598, 95% CI was 0.540-0.658, P = 0.02; when the cut-off value was 10.1, the sensitivity and specificity for predicting 28-day mortality was 75.2% and 58.0%, respectively; the AUC of NLR at 72 hours was 0.595, 95% CI was 0.536-0.655, P = 0.03; when the cut-off value was 9.24, the sensitivity and specificity for predicting 28-day mortality was 75.3% and 59.9%, respectively. Conclusions:NLR cannot predict the occurrence of AKI, ARDS, DIC and ALF in sepsis in early stage. NLR has a certain clinical value in predicting 28-day mortality in patients with sepsis, but its predictive efficiency is low.
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Objective To investigate the influence of heparin pretreatment on serum and lung tissue level of neutrophil extracellular traps (NETs) in septic mice model and its molecular mechanism.Methods Ninety male C57BL/6J mice were randomly divided into control group (n = 30), lipopolysaccharides (LPS) group (n = 30, 30 mg/kg LPS in 100μL normal saline was intraperitoneally injected) and LPS+heparin group (n = 30, 8 U of heparin in 20μL normal saline was subcutaneously injected 30 minutes before the injection of LPS). Six hours later of LPS injection, blood was collected and lung tissue was harvested. Enzyme linked immunosorbent assay (ELISA) was used to assess the concentration of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and histones 2AX (H2AX), neutrophil elastase (NE), which reflected NETs concentration. PicoGreen fluorescent dyes was used to detect serum circulating free DNA (cf-DNA/NETs) concentration. The protein expression levels of H2AX and NE in lung tissue were examined by Western Blot.Results The serum concentrations of TNF-α, IL-6, H2AX, NE, cf-DNA/NETs, and the protein expression levels of H2AX and NE in lung tissue of septic mice were significantly higher than those of control group [TNF-α (ng/L): 133.0±14.1 vs. 2.7±1.0, IL-6 (ng/L): 3911.2±189.2 vs. 298.9±52.5, H2AX (ng/L): 545.5±40.0 vs. 21.9±8.3, NE (μg/L): 6.48±0.12 vs. 0.47±0.15, cf-DNA/NETs (μg/L): 846.3±137.5 vs. 152.7±36.4, H2AX protein (gray value): 1.14±0.09 vs. 0.68±0.04, NE protein (gray value): 0.56±0.03 vs. 0.32±0.04, allP 0.05).Conclusion Heparin pretreatment could significantly decrease the level of NETs in serum and lung tissue, and can be the potential mechanism of its organ protection in sepsis.
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Objective To investigate the changes of neutrophil extracellular traps (NETs) level in plasma of sepsis patients and judge its clinical value for early diagnosing of sepsis.Methods A prospective observational study was conducted. The patients after surgery aged > 18 years and expected to stay in the ICU > 24 hours admitted to intensive care unit (ICU) of the First Affiliated Hospital of China Medical University from November 2014 to February 2015 were enrolled. According to the criteria of sepsis diagnosis in 1991, patients were divided into non-sepsis group and sepsis group. The healthy people who taken a physical examination were enrolled in the healthy control group. 3 mL peripheral venous blood was collected at 1 hour after admission to ICU. A fasting blood was collected in the healthy control group in the morning. The plasma free DNA (cf-DNA/NETs) was determined by using the fluorescence microplate reader, white blood cell (WBC), neutrophil ratio (NEU), procalcitonin (PCT), C-reactiveprotein (CRP) in peripheral blood of the patients were detected, and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) and sequential organ failure assessment (SOFA) scores were calculated. The correlation between plasma NETs and the risk factors in sepsis patients was analyzed by Spearman correlation analysis. The value of cf-DNA/NETs and WBC level in the diagnosis of sepsis was analyzed by using the receiver operating characteristic curve (ROC).Results Twenty-three sepsis patients, 20 non-sepsis patients, and 22 healthy persons were enrolled. There were no differences in baseline variables including gender and age among three groups, which indicated baseline data equalization. The plasma concentration of cf-DNA/NETs in sepsis group was significantly higher than that in non-sepsis group and healthy control group (μg/L: 453.44±185.37 vs. 188.35±29.66, 203.83±43.25, bothP 0.05). WBC, NEU, PCT, CRP, APACHE Ⅱ and SOFA score in sepsis group were significantly higher than those of non-sepsis group [WBC (×109/L): 9.52±5.51 vs. 5.97±2.28, NEU: 0.787±0.110 vs. 0.655±0.067, PCT (mg/L): 7.14 (3.60, 13.29) vs. 6.07 (3.57, 7.91), CRP (mg/L): 64.44±13.14 vs. 27.00±19.47, APACHE Ⅱ: 10.25±4.92 vs. 6.00±1.22, SOFA: 6.0±5.1 vs. 5.0±1.2, allP 0.05). The area under the ROC curve (AUC) of plasma cf-DNA/NETs for the diagnosis of sepsis was 0.981. When the cut-off valueof plasma cf-DNA/NETs was > 257.96μg/L, the sensitivity was 91.3%, specialty was 95.2%, and Youden index was 0.865. AUC of WBC in the diagnosis of sepsis was 0.663. When the cut-off value of WBC was > 6.0×109/L, the sensitivity was 78.3% and specificity was 25.0%.Conclusion The plasma cf-DNA/NETs levels increased significantly in sepsis patients. In the diagnosis of sepsis, plasma NETs levels had better advantages over WBC. NETs can be used as a biomarker for early diagnosis of sepsis.
ABSTRACT
Neutrophil extracellular traps (NETs) are net-like structure composed of DNA and nuclear proteins, which are produced by activated neutrophils under the circumstances of a variety of pathogens or drugs. As part of defensive mechanism, NETs have been proved to restrict the spread of pathogens and release of antimicrobial molecules. NETs can not only strengthen the adhesion between neutrophils and platelets, promote platelet mediated procoagulant reaction, but also lead to endothelial cell damage and coagulopathy in sepsis. In addition, NETs also plays an important role in pathophysiological processes of venous thrombosis. Therefore, NETs may become the biomarkers of evaluating coagulation dysfunction and potential therapy target in sepsis.