Epidemiologic trends of sepsis in western countries

The 14th International Podocyte Conference 2023: from podocyte biology to glomerular medicine

The 14th International Podocyte Conference took place in Philadelphia, Pennsylvania, USA from May 23 to 26, 2023. It commenced with an early-career researchers' meeting on May 23, providing young scientists with a platform to present and discuss their research findings. Throughout the main conference, 29 speakers across 9 sessions shared their insights on podocyte biology, glomerular medicine, novel technologic advancements, and translational approaches. Additionally, the event featured 3 keynote lectures addressing engineered chimeric antigen receptor T cell- and mRNA-based therapies and the use of biobanks for enhanced disease comprehension. Furthermore, 4 brief oral abstract sessions allowed scientists to present their findings to a broad audience. The program also included a panel discussion addressing the challenges of conducting human research within the American Black community. Remarkably, after a 5-year hiatus from in-person conferences, the 14th International Podocyte Conference successfully convened scientists from around the globe, fostering the presentation and discussion of crucial research findings, as summarized in this review. Furthermore, to ensure continuous and sustainable education, research, translation, and trial medicine related to podocyte and glomerular diseases for the benefit of patients, the International Society of Glomerular Disease was officially launched during the conference.

Retrospective analysis of pediatric sepsis and the burden of antimicrobial resistance in Duhok, Kurdistan Region of Iraq

Introduction: Sepsis is a life-threatening complication in pediatric patients. This study primarily aimed to investigate sepsis-causing bacteria and their antimicrobial resistance profile and check the change in the antimicrobial resistance trend for some selected bacteria. In addition, we evaluated the incidence of sepsis, the related mortality rate, and the effectiveness and outcome of the treatment regimes in sepsis pediatric patients. Methods: A retrospective analysis was conducted on 4-year data (2018-2021) collected from three intensive care units at the Hevi Pediatric Teaching Hospital. Sepsis screening involved clinical detection and confirmation by blood culture. Results: A total of 520 out of 1,098 (47.35%) blood samples showed positive microbial growth. A decrease in sepsis rate was observed during the COVID-19 pandemic. Coagulase-negative Staphylococci (CoNS) and Klebsiella pneumonia were the most commonly isolated bacteria. A notable variation in the antimicrobial resistance trend was observed among sepsis-causing bacteria. The empirical sepsis treatment recommended by the WHO was ineffective, as certain bacteria exhibited 100% resistance to every antibiotic tested. The mortality rate significantly increased from 1.3% in 2018 to 16.5% in 2021. Discussion: The antimicrobial resistance profile of sepsis causing bacteria is of concerns, indicating a potentially serious situation. Thus, to avoid treatment failure, the monitoring of antimicrobial resistance in pediatric patients is essential.

Increased Mortality Risk at Septic Condition in Inflammatory Skin Disorders and the Effect of High-Fat Diet Consumption

In recent years, attention has increasingly focused on various infectious diseases. Although some fatalities are directly attributed to the causative virus, many result from complications and reactive inflammation. Patients with comorbidities are at a higher risk of mortality. Refractory skin conditions such as atopic dermatitis, psoriasis, and epidermolysis bullosa, known for an elevated risk of sepsis, partly owe this to compromised surface barrier function. However, the detailed mechanisms underlying this phenomenon remain elusive. Conversely, although the detrimental effects of a high-fat diet on health, including the onset of metabolic syndrome, are widely recognized, the association between diet and susceptibility to sepsis has not been extensively explored. In this study, we examined the potential causes and pathogenesis of increased sepsis susceptibility in inflammatory skin diseases using a mouse dermatitis model: keratin 14-driven caspase-1 is overexpressed (KCASP1Tg) in mice on a high-fat diet. Our findings reveal that heightened mortality in the dermatitis mouse model is caused by the inflamed immune system due to the chronic inflammatory state of the local skin, and administration of LPS causes a rapid increase in inflammatory cytokine levels in the spleen. Intake of a high-fat diet exacerbates these cytokine levels. Interestingly, we also observed a reduced expression of Toll-like receptor 4 (TLR4) in monocytes from KCASP1Tg mice, potentially predisposing these animals to heightened infection risks and associated complications. Histological analysis showed a clear decrease in T and B cells in the spleen of KCASP1Tg mice fed a high-fat diet. Thickening of the alveolar wall, inflammatory cell infiltration, and alveolar hemorrhage were more prominent in the lungs of KCASP1Tg and KCASP1Tg with fat mice. We postulate that the chronic, non-infectious inflammation induces a negative feedback loop within the inflammatory cascade, and the suppressed expression of TLR4 renders the mice more susceptible to infections. Therefore, it is imperative for individuals with chronic skin inflammation to closely monitor disease progression upon infection and seek timely and appropriate treatment. Additionally, chronic inflammation of adipose tissue, induced by high-fat food intake, combined with dermatitis inflammation, may exacerbate infections, necessitating a review of dietary habits.

Sepsis-coded hospitalisations and associated costs in Australia: a retrospective analysis

OBJECTIVE

To report trends in Australian hospitalisations coded for sepsis and their associated costs.

DESIGN

Retrospective analysis of Australian national hospitalisation data from 2002 to 2021.

METHODS

Sepsis-coded hospitalisations were identified using the Global Burden of Disease study sepsis-specific ICD-10 codes modified for Australia. Costs were calculated using Australian-Refined Diagnosis Related Group codes and National Hospital Cost Data Collection.

RESULTS

Sepsis-coded hospitalisations increased from 36,628 in 2002-03 to 131,826 in 2020-21, an annual rate of 7.8%. Principal admission diagnosis codes contributed 13,843 (37.8%) in 2002-03 and 44,186 (33.5%) in 2020-21; secondary diagnosis codes contributed 22,785 (62.2%) in 2002-03 and 87,640 (66.5%) in 2020-21. Unspecified sepsis was the most common sepsis code, increasing from 15,178 hospitalisations in 2002-03 to 68,910 in 2020-21. The population-based incidence of sepsis-coded hospitalisations increased from 18.6 to 10,000 population (2002-03) to 51.3 per 10,000 (2021-21); representing an increase from 55.1 to 10,000 hospitalisations in 2002-03 to 111.4 in 2020-21. Sepsis-coded hospitalisations occurred more commonly in the elderly; those aged 65 years or above accounting for 20,573 (55.6%) sepsis-coded hospitalisations in 2002-03 and 86,135 (65.3%) in 2020-21. The cost of sepsis-coded hospitalisations increased at an annual rate of 20.6%, from AUD199M (€127 M) in financial year 2012 to AUD711M (€455 M) in 2019.

CONCLUSION

Hospitalisations coded for sepsis and associated costs increased significantly from 2002 to 2021 and from 2012 to 2019, respectively.

Identification of Potential Biomarkers of Septic Shock Based on Pathway and Transcriptome Analyses of Immune-Related Genes

Immunoregulation is crucial to septic shock (SS) but has not been clearly explained. Our aim was to explore potential biomarkers for SS by pathway and transcriptional analyses of immune-related genes to improve early detection. GSE57065 and GSE95233 microarray data were used to screen differentially expressed genes (DEGs) in SS. Gene Ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analyses of DEGs were performed, and correlations between immune cell and pathway enrichment scores were analyzed. The predictive value of candidate genes was evaluated by receiver operating characteristic (ROC) curves. GSE66099, GSE4607, and GSE13904 datasets were used for external validation. Blood samples from six patients and six controls were collected for validation by qRT-PCR and western blotting. In total, 550 DEGs in SS were identified; these genes were involved in the immune response, inflammation, and infection. Immune-related pathways and levels of infiltration of CD4 + TCM, CD8 + T cells, and preadipocytes differed between SS cases and controls. Seventeen genes were identified as potential biomarkers of SS (areas under ROC curves >0.9). The downregulation of CD8A, CD247, CD3G, LCK, and HLA-DRA in SS was experimentally confirmed. We identified several immune-related biomarkers in SS that may improve early identification of disease risk.

Prognostic significance of thyroid hormone T3 in patients with septic shock: a retrospective cohort study

Background

The role of thyroid hormones is crucial in the response to stress and critical illness, which has been reported to be closely associated with a poor prognosis in patients admitted to the intensive care unit (ICU). This study aimed to explore the relationship between thyroid hormone and prognosis in septic shock patients.

Methods

A total of 186 patients with septic shock were enrolled in the analytical study between December 2014 and September 2022. The baseline variables and thyroid hormone were collected. The patients were divided into survivor group and non-survivor group according to whether they died during the ICU hospitalization. Among 186 patients with septic shock, 123 (66.13%) were in the survivor group and 63 (33.87%) were in the non-survivor group.

Results

There were significant differences in the indictors of free triiodothyronine (FT3) (p = 0.000), triiodothyronine (T3) (p = 0.000), T3/FT3 (p = 0.000), acute physiology and chronic health evaluation II score (APACHE II) (p = 0.000), sequential organ failure assessment score (SOFA) (p = 0.000), pulse rate (p = 0.020), creatinine (p = 0.008), PaO2/FiO2 (p = 0.000), length of stay (p = 0.000) and hospitalization expenses (p = 0.000) in ICU between the two groups. FT3 [odds ratio (OR): 1.062, 95% confidence interval(CI): (0.021, 0.447), p = 0.003], T3 (OR: 0.291, 95% CI: 0.172-0.975, p = 0.037) and T3/FT3 (OR: 0.985, 95% CI:0.974-0.996, p = 0.006) were independent risk factors of the short-term prognosis of septic shock patients after adjustment. The areas under the receiver operating characteristic curves for T3 was associated with ICU mortality (AUC = 0.796, p < 0.05) and was higher than that for FT3 (AUC = 0.670, p < 0.05) and T3/FT3 (AUC = 0.712, p < 0.05). A Kaplan-Meier curve showed that patients with T3 greater than 0.48 nmol/L had a significantly higher survival rate than the patients with T3 less than 0.48 nmol/L.

Conclusions

The decrease in serum level of T3 in patients with septic shock is associated with ICU mortality. Early detection of serum T3 level could help clinicians to identify septic shock patients at high risk of clinical deterioration.

Inhibition of ITK Signaling Causes Amelioration in Sepsis-Associated Neuroinflammation and Depression-like State in Mice

Sepsis affects millions of people worldwide and is associated with multiorgan dysfunction that is a major cause of increased morbidity and mortality. Sepsis is associated with several morbidities, such as lung, liver, and central nervous system (CNS) dysfunction. Sepsis-associated CNS dysfunction usually leads to several mental problems including depression. IL-17A is one of the crucial cytokines that is expressed and secreted by Th17 cells. Th17 cells are reported to be involved in the pathogenesis of depression and anxiety in humans and animals. One of the protein tyrosine kinases that plays a key role in controlling the development/differentiation of Th17 cells is ITK. However, the role of ITK in sepsis-associated neuroinflammation and depression-like symptoms in mice has not been investigated earlier. Therefore, this study investigated the efficacy of the ITK inhibitor, BMS 509744, in sepsis-linked neuroinflammation (ITK, IL-17A, NFkB, iNOS, MPO, lipid peroxides, IL-6, MCP-1, IL-17A) and a battery of depression-like behavioral tests, such as sucrose preference, tail suspension, and the marble burying test. Further, the effect of the ITK inhibitor on anti-inflammatory signaling (Foxp3, IL-10, Nrf2, HO-1, SOD-2) was assessed in the CNS. Our data show that sepsis causes increased ITK protein expression, IL-17A signaling, and neuroinflammatory mediators in the CNS that are associated with a depression-like state in mice. ITK inhibitor-treated mice with sepsis show attenuated IL-17A signaling, which is associated with the upregulation of IL-10/Nrf2 signaling and the amelioration of depression-like symptoms in mice. Our data show, for the first time, that the ITK inhibition strategy may counteract sepsis-mediated depression through a reduction in IL-17A signaling in the CNS.

Dihydrotestosterone, and Not Testosterone, Enhances the LPS-Induced Inflammatory Cytokine Gene Expression in Human Adipocytes

BACKGROUND

The development of obesity-related complications lies in the low-grade inflammatory state consequent to adipocyte dysfunction. The direct involvement of sex hormones in adipose tissue inflammation has been previously suggested, but the evidence is scarce. In this study, we evaluated the effects of sex steroids on the in-vitroexpression of inflammatory mediators in human-derived adipocytes before and after lipopolysaccharide (LPS) exposure.

METHODS

Human adipocytes were differentiated from the vascular stromal fraction of adipose tissue samples of subjects undergoing abdominoplasty. We evaluated MCP-1, IL-1β, IL-6, and TNF-α gene expression in the presence of the main sex steroids, testosterone (T), and 17β-estradiol (E). Furthermore, we analyzed the effects of adipocytes exposure to the non-aromatizable androgen dihydrotestosterone (DHT), together with the effects of adipocytes pre-incubation with the aromatase inhibitor anastrozole alone (A), and in combination with T (A/T) before incubation with LPS.

RESULTS

DHT, but not T, significantly enhanced the LPSinduction of MCP-1, IL-1β, IL-6, and TNF-α. Intriguingly, the exposure of adipocytes with A/T dramatically increased the LPS-induced expression of all considered inflammatory cytokines, even more than a hundred-fold.

CONCLUSIONS

DHT and A/T dramatically enhance LPS-induced inflammatory cytokine expression in human-derived adipocytes. These results confirm the involvement of sex hormones in adipose tissue inflammation, suggesting a specific role for non-aromatizable androgens as the amplificatory sex hormones of the inflammatory response.

Septic Shock: Management and Outcomes

The incidence rates of sepsis and septic shock as a complication have become more common over the past several decades. With this increase, sepsis remains the most common cause of intensive care unit (ICU) admissions and one of the most mortality factors, with a huge burden on healthcare facilities. Septic shock has devastating consequences on patients' lives, including organ failures and other long-term complications. Due to its dynamic clinical presentations, guidelines and tools have been established to improve the diagnosis and management effectively. However, there is still a need for evidence-based standardized procedures for the diagnosis, treatment, and follow-up of sepsis and septic shock patients due to the inconsistency of current guidelines and studies contrasting with each other. The standardization would help physicians better manage sepsis, minimize complications and reduce mortality. Septic shock is usually challenging to manage due to its variety of clinical characteristics and physiologic dynamics, affecting the outcomes. Therefore, this review presented the available data in the literature on septic shock diagnosis, management, and prognosis to have an overview of the updated best practice approach to septic shock.

Accuracy of International Classification of Diseases, 10th Revision Codes for Identifying Sepsis: A Systematic Review and Meta-Analysis

Administrative databases are increasingly used in research studies to capture clinical outcomes such as sepsis. This systematic review and meta-analysis examines the accuracy of International Classification of Diseases, 10th revision (ICD-10), codes for identifying sepsis in adult and pediatric patients.

DATA SOURCES

We searched MEDLINE, EMBASE, Web of Science, CENTRAL, Epistemonikos, and McMaster Superfilters from inception to September 7, 2021.

STUDY SELECTION

We included studies that validated the accuracy of sepsis ICD-10 codes against any reference standard.

DATA EXTRACTION

Three authors, working in duplicate, independently extracted data. We conducted meta-analysis using a random effects model to pool sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). We evaluated individual study risk of bias using the Quality Assessment of Diagnostic Accuracy Studies tool and assessed certainty in pooled diagnostic effect measures using the Grading of Recommendations Assessment, Development, and Evaluation framework.

DATA SYNTHESIS

Thirteen eligible studies were included in the qualitative synthesis and the meta-analysis. Eleven studies used manual chart review as the reference standard, and four studies used registry databases. Only one study evaluated pediatric patients exclusively. Compared with the reference standard of detailed chart review and/or registry databases, the pooled sensitivity for sepsis ICD-10 codes was 35% (95% CI, 22-48, low certainty), whereas the pooled specificity was 98% (95% CI: 98-99, low certainty). The PPV for ICD-10 codes ranged from 9.8% to 100% (median, 72.0%; interquartile range [IQR], 50.0-84.7%). NPV ranged from 54.7% to 99.1% (median, 95.9%; interquartile range, 85.5-98.3%).

CONCLUSIONS

Sepsis is undercoded in administrative databases. Future research is needed to explore if greater consistency in ICD-10 code definitions and enhanced quality measures for ICD-10 coders can improve the coding accuracy of sepsis in large databases.

Mucin 1 Inhibits Ferroptosis and Sensitizes Vitamin E to Alleviate Sepsis-Induced Acute Lung Injury through GSK3β/Keap1-Nrf2-GPX4 Pathway

Background

Ferroptosis is a nonapoptotic form of programmed cell death, which may be related to the occurrence and development of sepsis-induced acute respiratory distress syndrome (ARDS)/acute lung injury (ALI). Mucin 1 (MUC1) is a kind of macromolecule transmembrane glycoprotein. Previous studies have shown that MUC1 could relieve ALI in sepsis and predict whether sepsis patients would develop into ARDS. However, the role of MUC1 in the ferroptosis of sepsis-induced ALI/ARDS remains unclear.

Materials and Methods

Sera samples from 50 patients with sepsis/septic shock were used to detect iron metabolism-related markers. Western blot and qRT-PCR were conducted to detect the expression levels of ferroptosis-related genes. Enzyme-linked immunosorbent assay (ELISA) was performed to evaluate inflammatory factors. Transmission electron microscopy (TEM) was used to assess morphological changes of cells.

Results

The results showed that the iron metabolism-related indicators in sepsis-induced ARDS patients changed significantly, suggesting the iron metabolism disorder. The expression levels of ferroptosis-related genes in lung tissues of sepsis had marked changes, and the lipid peroxidation levels increased, while Ferrostatin-1 (Fer-1) could reverse the above results, which confirmed the occurrence of ferroptosis. In terms of mechanism studies, inhibition of MUC1 dimerization could increase the expression level of Keap1, reduce the phosphorylation level of GSK3β, inhibit the entry of Nrf2 into the nucleus, further inhibit the expression level of GPX4, enhance the lipid peroxidation level of lung tissues, trigger ferroptosis, and aggravate lung injury. Besides, inhibiting MUC1 reversed the alleviating effect of vitamin E on ALI caused by sepsis, increased the aggregation of inflammatory cells in lung tissues, and aggravated alveolar injury and edema.

Conclusions

Our study was the first to explore the changes of iron metabolism indicators in ALI/ARDS of sepsis, clarify the important role of ferroptosis in ALI/ARDS induced by sepsis, and reveal the effects and specific mechanisms of MUC1 in regulating ferroptosis, as well as the sensitization on vitamin E.

Dexpanthenol attenuates inflammatory damage and apoptosis in kidney and liver tissues of septic mice

Sepsis is capable of causing systemic infections resulting in multiple organ damage. Dexpanthenol (DXP) has been reported to protect against kidney and liver injury. Therefore, this paper attempts to explore the role of DXP in sepsis-induced kidney and liver injury. A mice model of sepsis was established using the cecal ligation and puncture (CLP) method. The expressions of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and monocyte chemoattractant protein (MCP)-1 in the serum of mice were measured utilizing enzyme linked immunosorbent assay (ELISA). Additionally, the damage of kidney and liver tissues in CLP-induced mice was determined by their respective commercial kits, western blot, and hematoxylin–eosin (HE) staining kits. The apoptosis of kidney and liver tissues in CLP-induced mice was assessed by means of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and western blot. It was observed that DXP decreased the expressions of TNF-α, IL-1β, IL-6, and MCP-1 in the serum of CLP-induced mice, attenuated the functional impairment, pathological damage, inflammation, and cell apoptosis of kidney tissue. Meanwhile, DXP decreased the functional impairment of liver in CLP-induced mice, reduced the levels of inflammatory factors and antioxidant enzymes, attenuated liver pathological damage, and decreased cell apoptosis in liver tissues. In conclusion, DXP attenuates inflammatory damage and apoptosis in kidney and liver organs in a sepsis model.

Machine learning models to predict in-hospital mortality in septic patients with diabetes

BACKGROUND

Sepsis is a leading cause of morbidity and mortality in hospitalized patients. Up to now, there are no well-established longitudinal networks from molecular mechanisms to clinical phenotypes in sepsis. Adding to the problem, about one of the five patients presented with diabetes. For this subgroup, management is difficult, and prognosis is difficult to evaluate.

METHODS

From the three databases, a total of 7,001 patients were enrolled on the basis of sepsis-3 standard and diabetes diagnosis. Input variable selection is based on the result of correlation analysis in a handpicking way, and 53 variables were left. A total of 5,727 records were collected from Medical Information Mart for Intensive Care database and randomly split into a training set and an internal validation set at a ratio of 7:3. Then, logistic regression with lasso regularization, Bayes logistic regression, decision tree, random forest, and XGBoost were conducted to build the predictive model by using training set. Then, the models were tested by the internal validation set. The data from eICU Collaborative Research Database (n = 815) and dtChina critical care database (n = 459) were used to test the model performance as the external validation set.

RESULTS

In the internal validation set, the accuracy values of logistic regression with lasso regularization, Bayes logistic regression, decision tree, random forest, and XGBoost were 0.878, 0.883, 0.865, 0.883, and 0.882, respectively. Likewise, in the external validation set 1, lasso regularization = 0.879, Bayes logistic regression = 0.877, decision tree = 0.865, random forest = 0.886, and XGBoost = 0.875. In the external validation set 2, lasso regularization = 0.715, Bayes logistic regression = 0.745, decision tree = 0.763, random forest = 0.760, and XGBoost = 0.699.

CONCLUSION

The top three models for internal validation set were Bayes logistic regression, random forest, and XGBoost, whereas the top three models for external validation set 1 were random forest, logistic regression, and Bayes logistic regression. In addition, the top three models for the external validation set 2 were decision tree, random forest, and Bayes logistic regression. Random forest model performed well with the training and three validation sets. The most important features are age, albumin, and lactate.

Diagnostic and Prognostic Significance of the Prothrombin Time/International Normalized Ratio in Sepsis and Septic Shock

OBJECTIVE

The study investigates the diagnostic and prognostic significance of the prothrombin time/international normalized ratio (PT/INR) in patients with sepsis and septic shock.

BACKGROUND

Sepsis may be complicated by disseminated intravascular coagulation (DIC). While the status of coagulopathy of septic patients is represented within the sepsis-3 definition by assessing the platelet count, less data regarding the prognostic impact of the PT/INR in patients admitted with sepsis and septic shock is available.

METHODS

Consecutive patients with sepsis and septic shock from 2019 to 2021 were included. Blood samples were retrieved from day of disease onset (ie, day 0), as well as on day 1, 2, 4, 6 and 9 thereafter. Firstly, the diagnostic value of the PT/INR in comparison to the activated partial thromboplastin time (aPTT) was tested for septic shock compared to sepsis without shock. Secondly, the prognostic value of the PT/INR for 30-day all-cause mortality was tested. Statistical analyses included univariable t-tests, Spearman's correlations, C-statistics, Kaplan-Meier analyses and Cox proportional regression analyses.

RESULTS

338 patients were included (56% sepsis without shock, 44% septic shock). The overall rate of all-cause mortality at 30 days was 52%. With an area under the curve (AUC) of 0.682 (p= .001) on day 0, the PT/INR revealed moderate discrimination of septic shock and sepsis without shock. Furthermore, PT/ INR was able to discriminate non-survivors and survivors at 30 days (AUC = 0.612; p = .001). Patients with a PT/INR >1.5 had higher rates of 30-day all-cause mortality than patients with lower values (mortality rate 73% vs 48%; log rank p = .001; HR = 2.129; 95% CI 1.494-3.033; p = .001), even after multivariable adjustment (HR = 1.793; 95% CI 1.343-2.392; p = .001). Increased risk of 30-day all-cause mortality was observed irrespective of concomitant thrombocytopenia.

CONCLUSION

The PT/INR revealed moderate diagnostic accuracy for septic shock but was associated with reliable prognostic accuracy with regard to 30-day all-cause mortality in patients admitted with sepsis and septic shock.

Long noncoding RNA GSEC promotes neutrophil inflammatory activation by supporting PFKFB3-involved glycolytic metabolism in sepsis

Metabolic reprogramming is a hallmark of neutrophil activation in sepsis. LncRNAs play important roles in manipulating cell metabolism; however, their specific involvement in neutrophil activation in sepsis remains unclear. Here we found that 11 lncRNAs and 105 mRNAs were differentially expressed in three transcriptome datasets (GSE13904, GSE28750, and GSE64457) of gene expression in blood leukocytes and neutrophils of septic patients and healthy volunteers. After Gene Ontology biological process analysis and lncRNA-mRNA pathway network construction, we noticed that GSEC lncRNA and PFKFB3 were co-expressed and associated with enhanced glycolytic metabolism. Our clinical observations confirmed the expression patterns of GSEC lncRNA and PFKFB3 genes in neutrophils in septic patients. Performing in vitro experiments, we found that the expression of GSEC lncRNA and PFKFB3 was increased when neutrophils were treated with inflammatory stimuli. Knockdown and overexpression experiments showed that GSEC lncRNA was essential for mediating PFKFB3 mRNA expression and stability in neutrophil-like dHL-60 cells. In addition, we found that GSEC lncRNA-induced PFKFB3 expression was essential for mediating dHL-60 cell inflammatory cytokine expression. Performing mechanistic experiments, we found that glycolytic metabolism with PFKFB3 involvement supported inflammatory cytokine expression. In summary, our study uncovers a mechanism by which GSEC lncRNA promotes neutrophil inflammatory activation in sepsis by supporting glycolytic metabolism with PFKFB3.

D-Dimer Tests in the Emergency Department: Current Insights

In the Emergency Medicine setting, D-dimer is currently employed in the diagnostic assessment of suspected venous thromboembolism and aortic syndrome. The nonspecific symptoms reported by patients, like chest pain, dyspnea or syncope, uncover a wide range of differential diagnosis, spanning from mild to life-threatening conditions. Therefore, we assumed the perspective of the Emergency Physician and, in this narrative review, we reported a brief presentation of the epidemiology of these symptoms and the characteristics of patients, in whom we could suspect the aforementioned pathologies. We also reported in which patients D-dimer gives useful information. In fact, when the probability of the disease is high, the D-dimer level is futile. On the contrary, given the low specificity of the test, when the probability of the disease is very low, a false-positive value of the D-dimer only increases the risk of overtesting. Patients with low to moderate probability really benefit from the D-dimer testing, in order to prevent the execution of expensive and potentially dangerous imaging tests. In the second part of the review, we focused on the prognostic value of the test in septic patients. The early prognostic stratification of septic patients remains a challenge for the Emergency Physician, in the absence of a definite biomarker or score to rely on. Therefore, we need several parameters for the early identification of patients at risk of an adverse prognosis and the D-dimer may play a role in this demanding task. SARS COVID-19 patients represent an emerging reality, where the role of the D-dimer for prognostic stratification could be relevant. In fact, in patients with severe forms of this disease, the D-dimer reaches very high values, which appear to parallel the course of respiratory failure. Whether the test may add useful information for the management of these patients remains to be determined.

APOL1 risk variants in individuals of African genetic ancestry drive endothelial cell defects that exacerbate sepsis

The incidence and severity of sepsis is higher among individuals of African versus European ancestry. We found that genetic risk variants (RVs) in the trypanolytic factor apolipoprotein L1 (APOL1), present only in individuals of African ancestry, were associated with increased sepsis incidence and severity. Serum APOL1 levels correlated with sepsis and COVID-19 severity, and single-cell sequencing in human kidneys revealed high expression of APOL1 in endothelial cells. Analysis of mice with endothelial-specific expression of RV APOL1 and in vitro studies demonstrated that RV APOL1 interfered with mitophagy, leading to cytosolic release of mitochondrial DNA and activation of the inflammasome (NLRP3) and the cytosolic nucleotide sensing pathways (STING). Genetic deletion or pharmacological inhibition of NLRP3 and STING protected mice from RV APOL1-induced permeability defects and proinflammatory endothelial changes in sepsis. Our studies identify the inflammasome and STING pathways as potential targets to reduce APOL1-associated health disparities in sepsis and COVID-19.

Factors Associated With the Rate of Sepsis After Surgery

BACKGROUND

Sepsis is a critical illness that requires early detection and intervention to prevent disability and/or death.

OBJECTIVE

To analyze the association between various hospital-related factors and rates of sepsis after surgery in Massachusetts hospitals.

METHODS

The sample consisted of 53 hospitals with intensive or critical care units and 25 hospitals with step-down units. Hospital characteristics, staffing levels, and health care-acquired conditions were examined using publicly available data. Analysis of variance and linear regression were performed to explore the relationship between nurse and physician staffing levels and sepsis rates.

RESULTS

Sepsis rates were significantly lower when nurses cared for fewer patients (P < .001) and when intensivist hours were greater (P = .03). Linear regression for nurse staffing revealed that higher rates of catheter-associated urinary tract infection (P = .001) and higher numbers of step-down patients cared for by nurses (P = .001) were associated with a significantly higher rate of sepsis (P < .001). Linear regression for physician staffing revealed that higher rates of catheter-associated urinary tract infection (P < .001) and wound dehiscence after surgery (P < .001), greater hospitalist hours (P = .001), and greater physician hours (P = .05) were associated with a significantly higher sepsis rate, while greater intensivist hours were associated with a lower sepsis rate (P = .002).

CONCLUSION

In this study, greater nurse staffing and intensivist hours were associated with significantly lower rates of sepsis, whereas greater physician staffing and hospitalist hours were associated with significantly higher rates. Further research is needed to understand the roles of the various types of providers and the reasons for their differing effects on sepsis rates.

Transcriptome and Literature Mining Highlight the Differential Expression of ERLIN1 in Immune Cells during Sepsis

Sepsis results from the dysregulation of the host immune system. This highly variable disease affects 19 million people globally, and accounts for 5 million deaths annually. In transcriptomic datasets curated from public repositories, we observed a consistent upregulation (3.26-5.29 fold) of ERLIN1-a gene coding for an ER membrane prohibitin and a regulator of inositol 1, 4, 5-trisphosphate receptors and sterol regulatory element-binding proteins-under septic conditions in healthy neutrophils, monocytes, and whole blood. In vitro expression of the ERLIN1 gene and proteins was measured by stimulating the whole blood of healthy volunteers to a combination of lipopolysaccharide and peptidoglycan. Septic stimulation induced a significant increase in ERLIN1 expression; however, ERLIN1 was differentially expressed among the immune blood cell subsets. ERLIN1 was uniquely increased in whole blood neutrophils, and confirmed in the differentiated HL60 cell line. The scarcity of ERLIN1 in sepsis literature indicates a knowledge gap between the functions of ERLIN1, calcium homeostasis, and cholesterol and fatty acid biosynthesis, and sepsis. In combination with experimental data, we bring forth the hypothesis that ERLIN1 is variably modulated among immune cells in response to cellular perturbations, and has implications for ER functions and/or ER membrane protein components during sepsis.

LncRNA NEAT1 Promotes Inflammatory Response in Sepsis via the miR-31-5p/POU2F1 Axis

Sepsis is considered to be a systemic inflammatory response, which results in organ dysfunction. LncRNA nuclear-enriched abundant transcript 1 (NEAT1) involved in sepsis progression has been reported. However, the underlying mechanism of NEAT1 in sepsis-induced inflammatory response remains to be revealed. In this study, NEAT1 and POU domain class 2 transcription factor 1 (POU2F1) were highly expressed in LPS-induced septic RAW264.7 cells, opposite to miR-31-5p expression. Furthermore, we found that NEAT1 silencing inhibited LPS-induced inflammatory response and cell proliferation, and promoted cell apoptosis. Subsequently, we found that miR-31-5p interacted with NEAT1 and targeted the 3'UTR of POU2F1, and in LPS-induced RAW264.7 cells, the inhibition of NEAT1 silencing was reversed by miR-31-5p knockdown, while POU2F1 downregulation could cover the functions of miR-31-5p knockdown. In a word, this study indicates that NEAT1 inhibits the LPS-induced progression of sepsis in RAW264.7 cells by modulating miR-31-5p/POU2F1 axis, suggesting that NEAT1 will be the potential therapeutic target for sepsis.

Clinical Features and Etiology of Musculoskeletal Infection with or without Sepsis in the Emergency Department

Background

Musculoskeletal infection (MSKI) is a common reason to seek medical care in the emergency department (ED). We aimed to determine the clinical characteristics and etiology of patients with MSKI in our ED, the characteristics of MSKI with sepsis, and the predictors of death in sepsis patients.

Methods

The study retrospectively analyzed patients with MSKI from April 1, 2017, to March 31, 2021. The patients were divided into non-sepsis and sepsis groups. Clinical data of these patients including their basic information, laboratory results, diagnostic results, and outcomes were collected. Statistical analysis was carried out using GraphPad Prism 5.

Results

In all, 106 patients (70 male, 36 female) were enrolled in this study: 43 MSKI patients with sepsis and 63 MSKI patients without sepsis. Five patients with sepsis died. The patients’ age and sex ratio were no significantly different between the sepsis and non-sepsis groups. In the sepsis group, the ratio of rheumatic diseases, diabetes, coronary heart disease, and deep vein thrombosis was significantly different than that in the non-sepsis group (all p<0.05). Fifty-six patients (54.37%) had positive etiology results. Staphylococcus, streptococcus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli were the most common bacteria found in both groups, but sepsis patients had more Candida albicans infections than non-sepsis patients (p=0.0331, p<0.05). The five patients who died in the sepsis group had higher serum levels of creatinine and procalcitonin (PCT). Multivariate logistic regression analyses showed that PCT (p=0.026; odds ratio, 1.038) was significantly related to mortality.

Conclusion

In MSKI patients, rheumatic diseases, diabetes, coronary heart disease, and deep vein thrombosis are the risk factors for sepsis. Staphylococcus, streptococcus, K. pneumoniae, P. aeruginosa, and E. coli were the most common bacteria in MSKI patients, while MSKI patients with sepsis had more C. albicans infections. Elevated PCT was significantly related to death in sepsis patients.

Ulinastatin as an Adjuvant Therapy to Restricting Volumes of Resuscitation Fluid Strategy for Patients with Septic Shock after Initial Management

Septic shock is the most serious complication of sepsis, leading to unacceptably high morbidity and mortality worldwide. Fluid resuscitation using crystalloids has become the mainstay of early and aggressive treatment of severe sepsis and septic shock, while increased daily fluid balances from day 2 until day 7 have been related with increased mortality. Recently, pharmacological management has been recommended to combine with appropriate fluid resuscitation for the treatment of septic shock. In this study, we compared the clinical efficacy of restricting volumes of resuscitation fluid strategy with or without intravenous infusion of ulinastatin (UTI) in treating patients with septic shock and additionally examined the patient's changes of the extravascular lung water index (EVLWI), pulmonary vascular permeability index (PVPI), systemic vascular resistance index (SVRI), cardiac function, lactic acid (LA) level, coagulation function, and renal function. The study included 182 patients with septic shock, among which 89 patients had undergone restricting volumes of resuscitation fluid strategy with intravenous infusion of UTI and 93 patients had undergone restricting volumes of resuscitation fluid strategy alone. It was found that patients with septic shock after restricting volumes of resuscitation fluid strategy with intravenous infusion of UTI showed an increased SVRI concomitant with declined PVPI and EVLWI, increased mean artery pressure (MAP), cardiac output (CO), left ventricular ejection fraction (LVEF), stroke volume (SV), and heart rate (HR), declined levels of cardiac troponin I (cTnI), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and C-reactive protein (CRP), reduced LA level along with shortened prothrombin time (PT) and partially activated thrombin time (PATT), and decreased levels of blood urea nitrogen (BUN), creatinine (Cr), and uric acid (UA) when comparable to those after restricting volumes of resuscitation fluid strategy alone (P < 0.05). We also observed fewer scores of the Acute Physiology and Chronic Health Evaluation (APACHE II) and the sequential organ failure assessment (SOFA) in patients undergoing restricting volumes of resuscitation fluid strategy with intravenous infusion of UTI than those undergoing restricting volumes of resuscitation fluid strategy alone (P < 0.05). According to the above data, it is concluded that UTI as an adjuvant therapy for restricting volumes of resuscitation fluid strategy in treating septic shock may decrease the LA level, attenuate the inflammatory response, reduce vascular permeability, prevent pulmonary edema, and restore cardiac and renal functions.

Incidence of sepsis and associated mortality within the first year after cancer diagnosis in middle aged adults: A US population based study

Background

The incidence of sepsis has been rising overall but updated data in cancer patients are lacking. After a cancer diagnosis, incidence of sepsis and overall mortality peak within the first year. However, how much sepsis contributes to mortality remains unclear. We used a multistate model approach to analyze the incidence, risk factors and associated mortality of sepsis within 1 year of cancer diagnosis in middle aged adults.

Methods

Analysis of a large US health insurance claims database (Marketscan) between 2005 and 2014. Patients with a new diagnosis of cancer who received chemotherapy were included. Within a year of diagnosis, we assessed inpatient admissions for sepsis based on ICD-9 codes and survival using hospitalizations, outpatient visits and prescriptions filled. Competing risk and multistate models were used to assess the incidence of sepsis and transition probabilities between cancer, sepsis and death.

Results

119,379 patients (38.9% males), aged 55 (50–60) years, were included; 2,560 developed isolated sepsis, 477 severe sepsis and 1331 septic shock within 1 year, with associated hospital mortality of 14.8%, 30% and 46% respectively. The probability of sepsis increased between 2005 and 2014; at 1 year, its cumulative incidence was 3.7% with a probability of mortality after sepsis of 35.5% (95% CI 21.6%-50.9%). Age, male gender, Charlson comorbidity index, hematological malignancies and metastases at diagnosis were associated with sepsis and mortality.

Conclusions

Incidence and mortality of sepsis were 3.7% and 35.5% at 1 year after cancer diagnosis and were both associated with baseline patient and cancer characteristics.

Accelerate Pheno™ blood culture detection system: a literature review

Accelerate Pheno™ (ACC) is a fully automated system providing rapid identification of a panel of bacteria and yeasts, and antimicrobial susceptibility testing of common bacterial pathogens responsible for bloodstream infections and sepsis. Diagnostic accuracy for identification ranges from 87.9 to 100%, and antimicrobial susceptibility testing categorical agreement is higher than 91%. The present review includes peer-reviewed studies on ACC published to date. Both interventional and hypothetical studies evidenced the potential positive clinical role of ACC in the management and therapy of patients with bloodstream infections and sepsis, due to the important reduction in time to report, suggesting a crucial impact on the therapeutic management of these patients, provided the presence of a hospital antimicrobial stewardship program, a 24/7 laboratory operating time and a strict collaboration between clinical microbiologist and clinician. Further prospective multicenter studies are necessary to explore the impact of this system on mortality, length of stay and spread of multidrug-resistant organisms.

CYTL1 Promotes the Activation of Neutrophils in a Sepsis Model

As a novel cytokine, cytokine-like 1 (CYTL1) is a classical secretory protein, and its potential biological function remains to be determined. In this study, we found that expression of CYTL1 was upregulated in neutrophils upon inflammatory stimuli. We demonstrated that CYTL1 enhanced phagocytosis of Escherichia coli by activated neutrophils both in vivo and in vitro through phosphorylation of protein kinase B (Akt). CYTL1-induced chemotactic activity in lipopolysaccharide (LPS) stimulated neutrophils, and the mechanism may be related to CC chemokine receptor 2 (CCR2) mediated action. CYTL1 also increased the release of reactive oxygen species (ROS) in LPS-stimulated neutrophils. These data indicate that upon inflammatory stimulation, neutrophil-derived CYTL1 may play a crucial role in the activation of neutrophils during pathogenic infections.

TIM-3 Genetic Variants Are Associated with Altered Clinical Outcome and Susceptibility to Gram-Positive Infections in Patients with Sepsis

Background: Previous studies have reported the fundamental role of immunoregulatory proteins in the clinical phenotype and outcome of sepsis. This study investigated two functional single nucleotide polymorphisms (SNPs) of T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), which has a negative stimulatory function in the T cell immune response. Methods: Patients with sepsis (n = 712) were prospectively enrolled from three intensive care units (ICUs) at the University Medical Center Goettingen since 2012. All patients were genotyped for the TIM-3 SNPs rs1036199 and rs10515746. The primary outcome was 28-day mortality. Disease severity and microbiological findings were secondary endpoints. Results: Kaplan-Meier survival analysis demonstrated a significantly lower 28-day mortality for TIM-3 rs1036199 AA homozygous patients compared to C-allele carriers (18% vs. 27%, p = 0.0099) and TIM-3 rs10515746 CC homozygous patients compared to A-allele carriers (18% vs. 26%, p = 0.0202). The TIM-3 rs1036199 AA genotype and rs10515746 CC genotype remained significant predictors for 28-day mortality in the multivariate Cox regression analysis after adjustment for relevant confounders (adjusted hazard ratios: 0.67 and 0.70). Additionally, patients carrying the rs1036199 AA genotype presented more Gram-positive and Staphylococcus epidermidis infections, and rs10515746 CC homozygotes presented more Staphylococcus epidermidis infections. Conclusion: The studied TIM-3 genetic variants are associated with altered 28-day mortality and susceptibility to Gram-positive infections in sepsis.

Appropriateness of diagnosis and antibiotic use in sepsis patients admitted to a tertiary hospital in Indonesia

OBJECTIVE

To evaluate the diagnostic and antibiotic treatment strategies for patients suspected of sepsis, in a tertiary hospital in Indonesia. This can identify areas for improvement in care provided, and inform diagnostic and antimicrobial stewardship activities within the hospital.

METHODS

Retrospective review of medical records with regards to the diagnosis and management of adult patients with sepsis admitted to a tertiary hospital in Indonesia. We assessed the diagnostic process, and whether or not the antibiotic treatment provided was appropriate for the diagnosis. Appropriateness of antibiotic treatment was classified as being definite appropriate, probable appropriate, inappropriate, or unknown.

RESULTS

The study included 535 adult patients, of whom 295 (55%) were diagnosed with a community-acquired sepsis, and 240 (45%) with a hospital-acquired sepsis. A specimen for culture and antimicrobial susceptibility testing was collected from three out of four patients (392/535). All but 10 patients had information on antibiotic treatment at the time of sepsis diagnosis. Of those, nearly 50% (257/525) of the patients received antibiotic treatment with unknown appropriateness because no cultures were taken (n = 141) or all cultures were negative (n = 116). Just 3.4% and 9.1% of the patients received definite or probable appropriate antibiotic treatment, respectively.

CONCLUSIONS

There is a clear need in encouraging attending physicians to obtain the much-required blood cultures, or cultures from the suspected source of infection before empirical antibiotic treatment is started. This will improve the use of appropriate antibiotic treatment strategies, and contribute to antimicrobial stewardship.

Role of Gate-16 and Gabarap in Prevention of Caspase-11-Dependent Excess Inflammation and Lethal Endotoxic Shock

Sepsis is a life-threating multi-organ disease induced by host innate immunity to pathogen-derived endotoxins including lipopolysaccharide (LPS). Direct sensing of LPS by caspase-11 activates inflammasomes and causes lethal sepsis in mice. Inhibition of caspase-11 inflammasomes is important for the prevention of LPS-induced septic shock; however, whether a caspase-11 inflammasome-specific suppressive mechanism exists is unclear. Here we show that deficiency of GABARAP autophagy-related proteins results in over-activation of caspase-11 inflammasomes but not of canonical inflammasomes. Gate-16^−/−Gabarap^−/− macrophages exhibited elevated guanylate binding protein 2 (GBP2)-dependent caspase-11 activation and inflammatory responses. Deficiency of GABARAPs resulted in formation of GBP2-containing aggregates that promote IL-1β production. High mortality after low dose LPS challenge in Gate-16^−/−Gabarap^−/− mice primed with poly(I:C) or polymicrobial sepsis was ameliorated by compound GBP2 deficiency. These results reveal a critical function of Gate-16 and Gabarap to suppress GBP2-dependent caspase-11-induced inflammation and septic shock.

Oxidation-Specific Epitopes (OSEs) Dominate the B Cell Response in Murine Polymicrobial Sepsis

In murine abdominal sepsis by colon ascendens stent peritonitis (CASP), a strong increase in serum IgM and IgG antibodies was observed, which reached maximum values 14 days following sepsis induction. The specificity of this antibody response was studied in serum and at the single cell level using a broad panel of bacterial, sepsis-unrelated as well as self-antigens. Whereas an antibacterial IgM/IgG response was rarely observed, studies at the single-cell level revealed that IgM antibodies, in particular, were largely polyreactive. Interestingly, at least 16% of the IgM mAbs and 20% of the IgG mAbs derived from post-septic mice showed specificity for oxidation-specific epitopes (OSEs), which are known targets of the innate/adaptive immune response. This identifies those self-antigens as the main target of B cell responses in sepsis.

Identification of specific Tie2 cleavage sites and therapeutic modulation in experimental sepsis

Endothelial Tie2 signaling plays a pivotal role in vascular barrier maintenance at baseline and after injury. We previously demonstrated that a sharp drop in Tie2 expression observed across various murine models of critical illnesses is associated with increased vascular permeability and mortality. Matrix metalloprotease (MMP)-14-mediated Tie2 ectodomain shedding has recently been recognized as a possible mechanism for Tie2 downregulation in sepsis. Here, we identified the exact MMP14-mediated Tie2 ectodomain cleavage sites and could show that pharmacological MMP14 blockade in experimental murine sepsis exerts barrier protective and anti-inflammatory effects predominantly through the attenuation of Tie2 cleavage to improve survival both in a pre-treatment and rescue approach. Overall, we show that protecting Tie2 shedding might offer a new therapeutic opportunity for the treatment of septic vascular leakage.

Mortality after Severe Sepsis and Septic Shock in Swedish Intensive Care Units 2008-2016-A nationwide observational study

BACKGROUND

Recent studies have reported substantially decreased hospital mortality for sepsis, but data are scarcer on outcomes after hospital discharge. We studied mortality up to 1 year in Swedish intensive care unit (ICU) patients with and without sepsis.

METHODS

Demographic and medical data for all registered adult general ICU patients admitted between 01-01-2008 and 30-09-2016 were retrieved from the Swedish Intensive Care Registry and linked with the National Patient Register for comorbidity data and the Cause of Death Register for death dates. The population was divided in two cohorts; (a) Patients with a diagnosis of severe sepsis or septic shock and (b) All other ICU patients. Crude yearly mortality was calculated, and logistic regression was used to analyse predictors of mortality.

RESULTS

28 886 sepsis and 221 941 nonsepsis ICU patients were identified. In the sepsis cohort, in 2008 unadjusted mortality was 32.6% at hospital discharge, 32.7% at 30 days, 39% at 90 days and 46.8% at 365 days. In 2016, mortality was 30.5% at hospital discharge, 31.9% at 30 days and 38% at 90 days. Mortality at 365 days was 45.3% in 2015. Corresponding nonsepsis mortality was 15.4%, 16.2%, 20% and 26% in 2008 and 15.6%, 17.1%, 20.7% and 26.7% in 2016/2015. No consistent decrease in odds of mortality was seen in the adjusted analysis.

CONCLUSIONS

Mortality in severe sepsis and septic shock is high, with more than one in three patients not surviving three months after ICU admission, and adjusted mortality has not decreased convincingly in Sweden 2008-2016.

TRIAL REGISTRATION

The study was registered prospectively, ClinicalTrials.gov ID: NCT03489447.

Early Immunoparalysis Was Associated with Poor Prognosis in Elderly Patients with Sepsis: Secondary Analysis of the ETASS Study

Purpose

Although immune dysfunction has been investigated in adult septic patients, early immune status remains unclear. In this study, our primary aim was to assess early immune status in adult patients with sepsis stratified by age and its relevance to hospital mortality.

Patients and Methods

A post hoc analysis of a multicenter, randomized controlled trial was conducted; 273 patients whose immune status was evaluated within 48 hours after onset of sepsis were enrolled. Early immune status was evaluated by the percentage of monocyte human leukocyte antigen-DR (mHLA-DR) in total monocytes within 48 hours after onset of sepsis and it was classified as immunoparalysis (mHLA-DR ≤30%) or non-immunoparalysis (>30%). Three logistic regression models were conducted to explore the associations between early immunoparalysis and hospital mortality. We also developed two sensitivity analyses to find out whether the definition of early immune status (24 hours vs 48 hours after onset of sepsis) and immunotherapy affect the primary outcome.

Results

Of the 181 elderly (≥60yrs) and 92 non-elderly (<60yrs) septic patients, 71 (39.2%) and 25 (27.2%) died in hospital, respectively. The percentage of early immunoparalysis in the elderly was twice of that in the non-elderly patients (32% vs 16%, p=0.006). For the elderly, hospital mortality was higher in the immunoparalysis ones than the non-immunoparalysis ones (53.4% vs 32.5%, p=0.009). But there was no significant difference in hospital mortality between immunoparalysis non-elderly patients and non-immunoparalysis non-elderly ones (33.5% vs 26.0%, p=0.541). By means of logistic regression models, we found that early immunoparalysis was independently associated with increased hospital mortality in elderly, but not in non-elderly patients. Sensitivity analysis further confirmed the definition of early immune status and immunotherapy did not affect the outcomes.

Conclusion

The elderly were more susceptible to early immunoparalysis after onset of sepsis. Early immunoparalysis was independently associated with poor prognosis in elderly, but not in non-elderly patients.

Phagocytosis-Inflammation Crosstalk in Sepsis: New Avenues for Therapeutic Intervention

Phagocytosis is a complex process by which cells within most organ systems remove pathogens and cell debris. Phagocytosis is usually followed by inflammatory pathway activation, which promotes pathogen elimination and inhibits pathogen growth. Delayed pathogen elimination is the first step in sepsis development and a key factor in sepsis resolution. Phagocytosis thus has an important role during sepsis and likely contributes to all of its clinical stages. However, only a few studies have specifically explored and characterized phagocytic activity during sepsis. Here, we describe the phagocytic processes that occur as part of the immune response preceding sepsis onset and identify the elements of phagocytosis that might constitute a predictive marker of sepsis outcomes. First, we detail the key features of phagocytosis, including the main receptors and signaling hallmarks associated with different phagocytic processes. We then discuss how the initial events of phagosome formation and cytoskeletal remodeling might be associated with known sepsis features, such as a cytokine-driven hyperinflammatory response and immunosuppression. Finally, we highlight the unresolved mechanisms of sepsis development and progression and the need for cross-disciplinary approaches to link the clinical complexity of the disease with basic cellular and molecular mechanisms.

Antibody Production in Murine Polymicrobial Sepsis-Kinetics and Key Players

Although antigen-specific priming of antibody responses is impaired during sepsis, there is nevertheless a strong increase in IgM and IgG serum concentrations. Using colon ascendens stent peritonitis (CASP), a mouse model of polymicrobial abdominal sepsis, we observed substantial increases in IgM as well as IgG of all subclasses, starting at day 3 and peaking 2 weeks after sepsis induction. The dominant source of antibody-secreting cells was by far the spleen, with a minor contribution of the mesenteric lymph nodes. Remarkably, sepsis induction in splenectomized mice did not change the dynamics of the serum IgM/IgG reaction, indicating that the marginal zone B cells, which almost exclusively reside in the spleen, are dispensable in such a setting. Hence, in systemic bacterial infection, the function of the spleen as dominant niche of antibody-producing cells can be compensated by extra-splenic B cell populations as well as other lymphoid organs. Depletion of CD4+ T cells did not affect the IgM response, while it impaired IgG generation of all subclasses with the exception of IgG3. Taken together, our data demonstrate that the robust class-switched antibody response in sepsis encompasses both T cell-dependent and -independent components.

Efficacy and safety of iloprost in patients with septic shock-induced endotheliopathy-Protocol for the multicenter randomized, placebo-controlled, blinded, investigator-initiated trial

BACKGROUND

In Europe 700.000 new cases of sepsis occur annually and more than 100.000 of these patients die due to multiorgan failure (MOF). We have identified shock-induced endotheliopathy (SHINE) to be associated with development of MOF and mortality. Furthermore, in patients with septic shock those with circulating levels of thrombomodulin (TM) above 10 ng/mL have twice the mortality (56% vs 28%) than those with levels below this level. Pilot studies indicate that infusion of iloprost (1 ng/kg/min) is associated with improved endothelial function in patients with septic shock.

MATERIAL AND METHODS

This is a multicenter, randomized, blinded, investigator-initiated, adaptive phase 2B trial in up to 384 patients with septic shock-induced endotheliopathy defined by TM > 10 ng/mL who are allocated 1:1 to 72 hours continuous infusion of iloprost 1 ng/kg/min or placebo (equal volume of saline). The primary outcome is the mean daily modified Sequential Organ Failure Assessment (SOFA) score in the ICU up to day 90. Secondary outcomes include 28- and 90-day all-cause mortality, days alive without vasopressor in the ICU within 90 days, days alive without mechanical ventilation in the ICU within 90 days, days alive without renal replacement therapy in the ICU within 90 days, numbers of serious adverse reactions, and the number of serious adverse events within the first 7 days.

DISCUSSION

This trial tests the safety and efficacy of iloprost vs placebo for 72 hours in patients with septic shock and SHINE. The outcome measures focus on the potential effect of the intervention to mitigate organ failure.

TRIAL REGISTRATION

COMBAT-SHINE trial-EudraCT no. 2019-001131-31-Clinicaltrials.gov: NCT04123444-Ethics Committee no. H-19018258.

Secoeudesma sesquiterpenes lactone A alleviates inflammation and offers adjuvant protection in severe infection of carbapenem-resistant Klebsiella pneumoniae

ETHNOPHARMACOLOGICAL RELEVANCE

Secoeudesma sesquiterpenes lactone A (SESLA) is a sesquiterpene compound isolated from Inula japonica Thunb. (I. japonica). It is an herb widely distributed in Asian countries often used for the treatment of various conditions including tumors, bronchitis and bacterial and viral infections. It has been reported that SESLA could significantly inhibit the production of nitric oxide (NO) by lipopolysaccharide (LPS) in Raw264.7 cells. However, the mechanism responsible for this anti-inflammatory role and its role in the treatment of antibiotic-resistant bacterial infection, e.g., carbapenem-resistant Klebsiella pneumoniae (CRKP), remain to be investigated.

AIM OF THE STUDY

This study was carried out to investigate the protective anti-inflammatory role and the underlying molecular mechanisms of SESLA in LPS or CRKP evoked inflammation.

MATERIALS AND METHODS

ELISA and PCR were utilized to detect the expression of inflammatory mediators in LPS or heat-killed CRKP (HK CRKP)-stimulated immune cells containing different concentrations of SESLA. The protective role of SESLA was observed in mice challenged with a lethal dose of CRKP. Mice were intraperitoneally injected with CRKP to create a septic mouse model to evaluate the protective role of SESLA in vivo. Phosphorylated proteins, which represented the activation of signaling pathways, were examined by Western blot.

RESULTS

SESLA was showed to inhibit the expression of inflammatory mediators in various macrophages and dendritic cells upon stimulation of LPS or HK CRKP. It also facilitated phagocytosis of bacteria by Raw264.7 cells. The combined use of SELSA and the ineffective antibiotic, meropenem, increased the survival rate of CRKP infected mice from 25% to 50%. ERK, NF-κB and PI3K/Akt pathways accounted for the anti-inflammatory role of SESLA with the stimulation of LPS.

CONCLUSION

According to the notable anti-inflammatory effect in vitro and its joint protective effects on a septic mouse model, SESLA might act as an adjuvant drug candidate for sepsis, even those caused by antibiotic-resistant bacteria, e.g., CRKP.

Rapid multiplex detection of the resistance genes mecA, vanA and vanB from Gram-positive cocci-positive blood cultures using a PCR-dipstick technique

Introduction. Among the causative agents of bloodstream infections (BSIs), methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) are the key causative pathogens. Their rapid detection directly from Gram-positive cocci-positive blood culture specimens will promote timely treatment and help to implement effective infection control measures.Aim. We aim to develop a PCR-dipstick technique for the rapid detection of MRSA and VRE directly from positive blood culture specimens.Methodology. PCR-dipstick is a PCR-based multiplex detection technique where DNA-DNA hybridization is employed, and the results are interpreted with the naked eye. It was designed to target three drug resistance genes: mecA in MRSA and vanA/vanB in VRE from positive blood culture specimens. A total of 120 clinical isolates were used to evaluate the sensitivity and specificity of PCR-dipstick. Then, PCR-dipstick was examined for MRSA and VRE detection directly from positive blood cultures.Results. PCR-dipstick showed 100 % sensitivity and specificity in detecting mecA, vanA and vanB genes directly from bacterial colonies in comparison with multiplex PCR for genomic DNA followed by agarose gel electrophoresis. Further, it could differentially detect multiple resistant genes in pooled bacterial colonies (n=10). Ultimately, PCR-dipstick could detect MRSA and VRE in positive blood cultures in ~3 h.Conclusion. The results of the current study substantiate that PCR-dipstick can be used as an efficient detection system for MRSA and VRE directly from Gram-positive cocci-positive blood cultures. Its affordability and rapidity indicate that PCR-dipstick can be an effective tool for controlling nosocomial pathogens.

Pathological alteration and therapeutic implications of sepsis-induced immune cell apoptosis

Sepsis is a life-threatening organ dysfunction syndrome caused by dysregulated host response to infection that leads to uncontrolled inflammatory response followed by immunosuppression. However, despite the high mortality rate, no specific treatment modality or drugs with high efficacy is available for sepsis to date. Although improved treatment strategies have increased the survival rate during the initial state of excessive inflammatory response, recent trends in sepsis show that mortality occurs at a period of continuous immunosuppressive state in which patients succumb to secondary infections within a few weeks or months due to post-sepsis “immune paralysis.” Immune cell alteration induced by uncontrolled apoptosis has been considered a major cause of significant immunosuppression. Particularly, apoptosis of lymphocytes, including innate immune cells and adaptive immune cells, is associated with a higher risk of secondary infections and poor outcomes. Multiple postmortem studies have confirmed that sepsis-induced immune cell apoptosis occurs in all age groups, including neonates, pediatric, and adult patients, and it is considered to be a primary contributing factor to the immunosuppressive pathophysiology of sepsis. Therapeutic perspectives targeting apoptosis through various strategies could improve survival in sepsis. In this review article, we will focus on describing the major apoptosis process of immune cells with respect to physiologic and molecular mechanisms. Further, advances in apoptosis-targeted treatment modalities for sepsis will also be discussed.

Epidemiology of sepsis in cancer patients in Victoria, Australia: a population-based study using linked data

OBJECTIVE

To determine the clinical characteristics, outcomes and longitudinal trends of sepsis occurring in cancer patients.

METHOD

Retrospective study using statewide Victorian Cancer Registry data linked to various administrative datasets.

RESULTS

Among 215,763 incident cancer patients, incidence of sepsis within one year of cancer diagnosis was estimated at 6.4%. The incidence of sepsis was higher in men, younger patients, patients diagnosed with haematological malignancies and those with de novo metastatic disease. Of the 13,316 patients with a first admission with sepsis, 55% had one or more organ failures, 29% required care within an intensive care unit and 13% required mechanical ventilation. Treatments associated with the highest sepsis incidence were stem cell/bone marrow transplant (33%), major surgery (4.4%), chemotherapy (1.1%) and radical radiotherapy (0.6%). The incidence of sepsis with organ failure increased between 2008 and 2015, while 90-day mortality decreased.

CONCLUSIONS

Sepsis in patients with cancer has high mortality and occurs most frequently in the first year after cancer diagnosis. Implications for public health: The number of cancer patients diagnosed with sepsis is expected to increase, causing a substantial burden on patients and the healthcare system.

Quinolones for sepsis. A protocol for a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis

BACKGROUND

Sepsis is a relatively common and deadly condition that constitutes a major challenge to the modern health care system. Quinolones are sometimes used in combination with beta-lactam antibiotics for sepsis, but no former systematic review has assessed the benefits and harms of quinolones in patients with sepsis.

METHODS

We will perform a systematic review with meta-analysis and trial sequential analysis including randomised clinical trials assessing the effects of quinolones as add on therapy to usual care in children and adults with sepsis. For the assessment of harms, we will also include quasi-randomised studies and observational studies identified during our searches for randomised clinical trials.

DISCUSSION

This systematic review will clarify if there is evidence to support quinolones being part of the standard treatment for sepsis.

TNFAIP3, TNIP1, and MyD88 Polymorphisms Predict Septic-Shock-Related Death in Patients Who Underwent Major Surgery

Background: In many immune-related diseases, inflammatory responses and several clinical outcomes are related to increased NF-κB activity. We aimed to evaluate whether SNPs related to the NF-κB signaling pathway are associated with higher susceptibility to infection, septic shock, and septic-shock-related death in European patients who underwent major surgery. Methods: We performed a case-control study on 184 patients with septic shock and 212 with systemic inflammatory response syndrome, and a longitudinal substudy on septic shock patients. Thirty-three SNPs within genes belonging to or regulating the NF-κB signaling pathway were genotyped by Agena Bioscience’s MassARRAY platform. Results: No significant results were found for susceptibility to infection and septic shock in the multivariate analysis after adjusting for multiple comparisons. Regarding septic-shock-related death, patients with TNFAIP3 rs6920220 AA, TNIP1 rs73272842 AA, TNIP1 rs3792783 GG, and TNIP1 rs7708392 CC genotypes had the highest risk of septic-shock-related death in the first 28 and 90 days. Also, the MyD88 rs7744 GG genotype was associated with a higher risk of death during the first 90 days. Haplotype analysis shows us that patients with the TNIP1 GAG haplotype (composed of rs73272842, rs3792783, and rs7708392) had a lower risk of death in the first 28 days and the TNIP1 AGC haplotype was associated with a higher risk of death in the first 90 days. Conclusions: The SNPs in the genes TNFAIP3, TNIP1, and MyD88 were linked to the risk of septic-shock-related death in patients who underwent major surgery.

Mitochondrial quality control mechanisms as potential therapeutic targets in sepsis-induced multiple organ failure

Sepsis is a dysregulated response to severe infection characterized by life-threatening organ failure and is the leading cause of mortality worldwide. Multiple organ failure is the central characteristic of sepsis and is associated with poor outcome of septic patients. Ultrastructural damage to the mitochondria and mitochondrial dysfunction are reported in sepsis. Mitochondrial dysfunction with subsequent ATP deficiency, excessive reactive oxygen species (ROS) release, and cytochrome c release are all considered to contribute to organ failure. Consistent mitochondrial dysfunction leads to reduced mitochondrial quality control capacity, which eliminates dysfunctional and superfluous mitochondria to maintain mitochondrial homeostasis. Mitochondrial quality is controlled through a series of processes including mitochondrial biogenesis, mitochondrial dynamics, mitophagy, and transport processes. Several studies have indicated that multiple organ failure is ameliorated by restoring mitochondrial quality control mechanisms and is further amplified by defective quality control mechanisms. This review will focus on advances concerning potential mechanisms in regulating mitochondrial quality control and impacts of mitochondrial quality control on the progression of sepsis.

LDK378 improves micro- and macro-circulation via alleviating STING-mediated inflammatory injury in a Sepsis rat model induced by Cecal ligation and puncture

Background

Sepsis is a systemic inflammatory response syndrome caused by severe infections. LDK378, a second-generation ALK inhibitor, exhibits a potential anti-inflammatory function against sepsis. Micro- and macro-circulatory dysfunctions are pivotal elements of the pathogenesis of severe sepsis and septic shock. We hypothesized that LDK378 can improve micro- and macro-circulation of septic rats, therefore improving the outcome of survival via blocking the ALK-STING pathway to attenuate inflammatory injuries.

Methods

A septic rat model was established by the cecal ligation and puncture (CLP) method. A total of 60 rats were randomized into three groups: a sham group, CLP group, and CLP + LDK378 group (n = 20 in each group). Five rats were randomly selected from each group for the mechanism study; the remaining 15 rats in each group were involved in a survival curve examination. A sidestream dark field video microscope was used to record sublingual microcirculation and mean arterial pressure (MAP) and levels of inflammatory cytokine secretion were examined at 6 h, 30 h, and 54 h after CLP surgery. Expressions of TANK binding kinase 1 (TBK1) and its downstream targets were determined, and histological alterations to the heart, lungs, and kidneys were examined at 54 h after CLP surgery.

Results

We found the group that received LDK378 treatment showed increased MAP levels compared to the CLP group at 30 h and 54 h. Meanwhile, LDK378 ameliorated the perfused small vessel density and microvascular flow index, decreased the expression of TNF-a and IL-6, and upregulated the expression of IL-10 in comparison with the CLP group. LDK378 injections also downregulated the expression of TBK1 and its downstream targets. Furthermore, LDK378 treatment significantly reduced sepsis-induced organ injuries, therefore improving survival rates.

Conclusions

These findings demonstrate that LDK378 treatment can improve microcirculation and reduce organ injuries in CLP-induced septic rats via the regulation of inflammatory cytokine secretion and the downstream signaling components of the ALK-STING pathway.

A computational analysis of dynamic, multi-organ inflammatory crosstalk induced by endotoxin in mice

Bacterial lipopolysaccharide (LPS) induces an acute inflammatory response across multiple organs, primarily via Toll-like receptor 4 (TLR4). We sought to define novel aspects of the complex spatiotemporal dynamics of LPS-induced inflammation using computational modeling, with a special focus on the timing of pathological systemic spillover. An analysis of principal drivers of LPS-induced inflammation in the heart, gut, lung, liver, spleen, and kidney to assess organ-specific dynamics, as well as in the plasma (as an assessment of systemic spillover), was carried out using data on 20 protein-level inflammatory mediators measured over 0-48h in both C57BL/6 and TLR4-null mice. Using a suite of computational techniques, including a time-interval variant of Principal Component Analysis, we confirm key roles for cytokines such as tumor necrosis factor-α and interleukin-17A, define a temporal hierarchy of organ-localized inflammation, and infer the point at which organ-localized inflammation spills over systemically. Thus, by employing a systems biology approach, we obtain a novel perspective on the time- and organ-specific components in the propagation of acute systemic inflammation.

Gram-negative bacterial lipopolysaccharide (LPS) is both a central mediator of sepsis and a canonical inducer of acute inflammation via Toll-like receptor 4 (TLR4). Sepsis involves the systemic spillover of inflammation that normally remains localized in individual organs. The goal of this study was to gain insights into 1) early vs. later drivers of LPS-induced inflammation in various compartments, and 2) the systemic spillover from affected organs vs. local production of inflammatory mediators in the blood. This study involved a large number of data points on the dynamics of inflammatory mediators at the protein level, data-driven computational modeling of principal characteristics and cross-correlations, and validation of key hypotheses. In addition to verifying key mechanisms in LPS/TLR4-driven acute inflammation, this approach yielded key insights into the progression of inflammation across tissues, and also suggested the presence of TLR4-independent pathways (especially in the gut). This is, to our knowledge, the first study examining the dynamic evolution of some key inflammatory mediators and their interactions with each other in both the systemic circulation and within a number of targeted parenchymal organs in mice.

Developments to monitor the exhalome in organ failure in critically ill patients-a look into the future

Critically ill patients typically need some kind of functional organ support or replacement. Cardiopulmonary and renal replacement therapies are well established measures in intensive care units. However, there are also inherent risks associated with these treatments. The appropriate and timely commencement, maintenance and termination of organ replacement procedures currently use weak surrogates as decision support in clinical practice. A more reasonable application of extracorporeal organ support can be expected to potentially lower adverse events and save costs in healthcare systems, if a precise online monitoring was available. The analysis of the exhalome offers great opportunities to detect circulatory, pulmonary, and renal failure in critically ill patients. Volatile organic compounds and exhalation patterns are associated with a series of metabolic disorders and may be key to indicate the appropriate time point for initiation, maintenance and termination of organ support technologies. It may thus be expected that mortality, infection risk, replacement therapy days, and medical costs of intensive care treatment may possibly be reduced using exhalome analysis for control of organ replacement therapies in the distant future.

The role of mitochondria in sepsis-induced cardiomyopathy

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. Myocardial dysfunction, often termed sepsis-induced cardiomyopathy, is a frequent complication and is associated with worse outcomes. Numerous mechanisms contribute to sepsis-induced cardiomyopathy and a growing body of evidence suggests that bioenergetic and metabolic derangements play a central role in its development; however, there are significant discrepancies in the literature, perhaps reflecting variability in the experimental models employed or in the host response to sepsis. The condition is characterised by lack of significant cell death, normal tissue oxygen levels and, in survivors, reversibility of organ dysfunction. The functional changes observed in cardiac tissue may represent an adaptive response to prolonged stress that limits cell death, improving the potential for recovery. In this review, we describe our current understanding of the pathophysiology underlying myocardial dysfunction in sepsis, with a focus on disrupted mitochondrial processes.