Unraveling the immunological landscape in acute pancreatitis progression to sepsis: insights from a Mendelian randomization study on immune cell traits.

Background: Acute pancreatitis (AP) is a severe digestive system disorder with a significant risk of progressing to sepsis, a major cause of mortality. Unraveling the immunological pathways in AP is essential for developing effective treatments, particularly understanding the role of specific immune cell traits in this progression. Methods: Employing a bidirectional two-sample Mendelian Randomization (MR) approach, this study first examined the causal relationship between AP and 731 immune cell traits to identify those significantly associated with AP. Subsequently, we explored the causal associations between 731 immune cell traits and sepsis. The analysis utilized extensive genome-wide association studies (GWAS) summary datasets, with a focus on identifying common immune cell traits with statistically significant causal associations between AP and sepsis. Results: Our investigation identified 44 immune cell traits unidirectionally associated with AP and 36 traits unidirectionally associated with sepsis. Among these, CD127 on CD28+ CD45RA- CD8+ T cells emerged as a common mediator, accounting for 5.296% of the increased risk of sepsis in AP patients. This finding highlights the significant role of specific memory CD8+ T cells in the pathophysiology of AP and its progression to sepsis. Conclusion: This study elucidates the critical role of specific immune cell traits, particularly CD127hi memory CD8+ T cells, in the progression of AP to sepsis. Our findings provide a foundation for future research into targeted immune-modulatory therapies, potentially improving patient outcomes in AP-related sepsis and offering new insights into the complex immunological dynamics of this condition.

Development and external validation of a nomogram for the early prediction of acute kidney injury in septic patients: a multicenter retrospective clinical study.

Background and purpose: Acute kidney injury (AKI) is a common serious complication in sepsis patients with a high mortality rate. This study aimed to develop and validate a predictive model for sepsis associated acute kidney injury (SA-AKI). Methods: In our study, we retrospectively constructed a development cohort comprising 733 septic patients admitted to eight Grade-A tertiary hospitals in Shanghai from January 2021 to October 2022. Additionally, we established an external validation cohort consisting of 336 septic patients admitted to our hospital from January 2017 to December 2019. Risk predictors were selected by LASSO regression, and a corresponding nomogram was constructed. We evaluated the model's discrimination, precision and clinical benefit through receiver operating characteristic (ROC) curves, calibration plots, decision curve analysis (DCA) and clinical impact curves (CIC) in both internal and external validation. Results: AKI incidence was 53.2% in the development cohort and 48.2% in the external validation cohort. The model included five independent indicators: chronic kidney disease stages 1 to 3, blood urea nitrogen, procalcitonin, D-dimer and creatine kinase isoenzyme. The AUC of the model in the development and validation cohorts was 0.914 (95% CI, 0.894-0.934) and 0.923 (95% CI, 0.895-0.952), respectively. The calibration plot, DCA, and CIC demonstrated the model's favorable clinical applicability. Conclusion: We developed and validated a robust nomogram model, which might identify patients at risk of SA-AKI and promising for clinical applications.

Association Between Nonthyroidal Illness Syndrome and Disseminated Intravascular Coagulation in Sepsis.

Purpose: Both nonthyroidal illness syndrome (NTIS) and disseminated intravascular coagulation (DIC) are commonly occurred in sepsis. The objective of this study is to evaluate the association between NTIS and DIC, as well as their impacts on the mortality in adults with sepsis. Patients and methods: A total of 1219 septic patients in two Chinese academic centers from October 2012 and October 2022 were enrolled in analysis. We conduct logistic regression models to analyze the independent risk factors for DIC. Modified Poisson regression models are used to estimate the relative risk (RR) of NTIS on the 28 days mortality in septic patients with DIC. Correlation analysis between thyroid function parameters and coagulation parameters is performed with Pearson coefficient be reported. Results: DIC is diagnosed on 388 (31.8%) of all the 1219 enrolled septic patients within 72 hours after admission. In multivariate logistic regression models, NTIS (OR 3.19; CI 2.31-4.46; p<0.001) is a statistically significant independent risk factor for DIC after adjustment for potential confounders. Twenty-eight days mortality is significantly higher in DIC patients complicated with NTIS compared with the other DIC patients (23.2% vs 14.0%, p=0.024). This result is also robust in different modified Poisson regression models (Model 1: RR 1.46; CI 1.25-1.70; p<0.001; Model 2: RR 1.35; CI 1.14-1.60; p<0.001; Model 3: RR 1.18; CI 1.02-1.37; p=0.026). Correlation analysis reveals that the thyroid function parameters of FT3, FT4 and TSH only have weak correlations with coagulation parameters of platelet count, fibrinogen, FDP, D-dimers, PT, APTT and INR in sepsis. Conclusion: NTIS is an independent risk factor for DIC in adults with sepsis. DIC patients complicated with NTIS have significantly higher severity and higher rate of mortality.

Septic macrophages induce T cells immunosuppression in a cell-cell contact manner with the involvement of CR3.

Background: In addition to excessive inflammation, immunosuppression has been recognized as a contributing factor to poor prognosis of sepsis. Although it has been reported that T cells can become functionally impaired during sepsis, the underlying mechanisms responsible for this phenomenon remain unclear. This study aims to elucidate the mechanisms by which macrophages induce immunosuppression in T cells. Methods: In an in vivo setting, C57BL-6J mice were subjected to cecal ligation and puncture (CLP) with or without depletion of macrophages, and the functions of T cells were assessed. In vitro experiments involved direct co-culture or separate culture of T cells and septic macrophages using a transwell system, followed by analysis of T cell immunity. Additionally, a siRNA targeting CD18 on macrophages was utilized to investigate the role of complement receptor 3 (CR3). Results: Both macrophages and T cells exhibited immunosuppression during sepsis. In the in vivo experiments, the absence of macrophages partially alleviated T cell immunosuppression, as evidenced by restored vitality, increased production of TNF-α and IFN-γ, elevated CD8+ T cell levels, and decreased CD25+ T cell levels. In the in vitro experiments, direct co-culture of T cells with septic macrophages resulted in diminished T cell immunity, which was improved when T cells and macrophages were separated by a chamber wall. The expression of CR3 (CD11b/CD18) was upregulated on septic macrophages, and silencing of CD18 led to decreased TNF-α production by T cells, reduced CD4+ T cell numbers, and increased CD25+ T cell numbers. Conclusion: In sepsis, macrophages induce immunosuppression in T cells through direct cell-cell contact, with the involvement of CR3.

MSCs-derived extracellular vesicles alleviate sepsis-associated liver dysfunction by inhibiting macrophage glycolysis-mediated inflammatory response.

Sepsis-associated liver dysfunction (SALD) aggravates the disease progression and prognosis of patients. Macrophages in the liver play a crucial role in the occurrence and development of SALD. Human umbilical cord mesenchymal stem cells (MSCs), by secreting extracellular vesicles (EVs), show beneficial effects in various inflammatory diseases. However, whether MSC-derived EVs (MSC-EVs) could ameliorate the inflammatory response in liver macrophages and the underlying mechanisms remain unclear. In this study, a mouse model of sepsis induced by lipopolysaccharide (LPS) challenge was used to investigate the immunomodulatory functions of MSC-EVs in SALD. LPS-stimulated primary Kupffer cells (KCs) and Raw264.7 were used to further explore the potential mechanisms of MSC-EVs in regulating the inflammatory response of macrophages. The results showed that MSC-EVs alleviated liver tissue injury and facilitated the polarization of M1 to M2 macrophages. Further in vitro studies confirmed that MSC-EVs treatment significantly downregulated the expression of several enzymes related to glycolysis and reduced the glycolytic flux by inhibiting hypoxia-inducible factor 1α (HIF-1α) expression, thus effectively inhibiting the inflammatory responses of macrophages. These findings reveal that the application of MSC-EVs might be a potential therapeutic strategy for treating SALD.

Early encapsulation of peripancreatic fluid/necrosis collections on imaging (CECT) in acute pancreatitis: influential factors and clinical significance for prognosis.

BACKGROUND: To identify the factors influencing the early encapsulation of peripancreatic fluid/necrosis collections via contrast-enhanced computed tomography (CECT) and to determine the clinical significance of early encapsulation for determining the prognosis of acute pancreatitis (AP) patients. METHODS: AP patients who underwent CECT between 4 and 10 days after disease onset were enrolled in this study. Early encapsulation was defined as a continuous enhancing wall around peripancreatic fluid/necrosis collections on CECT. Univariate and multivariate logistic regression analyses were performed to assess the associations between the variables and early encapsulation. Clinical outcomes were compared between the non-encapsulation and early encapsulation groups with 1:1 propensity score matching. RESULTS: A total of 289 AP patients were enrolled. The intra-observer and inter-observer agreement were considered good (kappa statistics of 0.729 and 0.614, respectively) for identifying early encapsulation on CECT. The ratio of encapsulation increased with time, with a ratio of 12.5% on day 5 to 48.7% on day 9. Multivariate logistic regression analysis revealed that the longer time from onset to CECT examination (OR 1.55, 95% CI 1.23-1.97), high alanine aminotransferase level (OR 0.98, 95% CI 0.97-0.99), and high APACHE II score (OR 0.89, 95% CI 0.81-0.98) were found to be independent factors associated with delayed encapsulation. The incidence of persistent organ failure was significantly lower in the early encapsulation group after matching (22.4% vs 6.1%, p = 0.043). However, there was no difference in the incidence of infected pancreatic necrosis, surgical intervention, or in-hospital mortality. CONCLUSIONS: AP patients without early encapsulation of peripancreatic fluid/necrosis collections have a greater risk of persistent organ failure. In addition to longer time, the high APACHE II score and elevated alanine aminotransferase level are factors associated with delayed encapsulation.

Lysine acetyltransferase KAT2A modulates ferroptosis during colorectal cancer development.

BACKGROUND: Histone modifications, especially the lysine acetylation, have drawn increasing attention in cancer research area. The aim of this research is to explore the molecular mechanisms underlying the regulation of lysine acetyltransferase 2 A (KAT2A) on colorectal cancer (CRC). METHODS: Clinical samples were collected from patients with CRC. The expression and correlation between KAT2A and ferroptosis suppressor SLC7A11 and glutathione peroxidase 4 (GPX4) were measured by qPCR and Pearson correlation analysis. NCP cells were transfected with KAT2A overexpression vectors or siRNAs. The proliferation of cells was measured by CCK-8 and colony formation assay. Cell migration and invasion was analyzed by Transwell. The accumulation of lipid peroxidation, ferrous iron, and malondialdehyde (MDA) were analyzed to determine cell ferroptosis. The expression of cell metastasis biomarkers was measured by western blotting assay. Interaction between KAT2A with GPX4 gene was measured by chromatin immunoprecipitation (ChIP). RESULTS: The KAT2A, GPX4, and SLC7A11 expression was notably elevated in tumor tissues compared with the paired non-tumor tissues from CRC patients. The expression of KAT2A showed positive correlation with GPX4 and SLC7A11. Overexpression of KAT2A recovered the cell proliferation, migration, and invasion of CRC cells that suppressed by ferroptosis inducer erastin, along with deceased levels of ROS, iron, Fe2+, and MDA. Overexpression of KAT2A suppressed E-cadherin level and increased N-cadherin, Snail, and Vimentin expression in CRC cells. KAT2A interacted with GPX4 promoter region. CONCLUSIONS: In conclusion, our findings demonstrated that KAT2A modulates the histone acetylation of GPX4 to regulate proliferation, metastasis, and ferroptosis of CRC cells.

Effect of early antibiotic treatment strategy on prognosis of acute pancreatitis.

BACKGROUND: Antibiotic use in the early stages of acute pancreatitis is controversial. The purpose of this study was to investigate the effect of early antibiotic application on the prognosis of acute pancreatitis (AP). MATERIALS AND METHODS: Clinical data of patients with primary AP admitted to our emergency ward within 72 hours of onset were retrospectively collected from January 2016 to December 2020. We classified patients with acute pancreatitis according to etiology and disease severity, and compared the differences in hospital stay, laparotomy rate, and in-hospital mortality among AP patients who received different antibiotic treatment strategies within 72 hours of onset. RESULTS: A total of 1134 cases were included, with 681 (60.1%) receiving early antibiotic treatment and 453 (39.9%) not receiving it. There were no significant differences in baseline values and outcomes between the two groups. In subgroup analysis, patients with biliary severe acute pancreatitis (SAP) who received early antibiotics had lower rates of laparotomy and invasive mechanical ventilation, as well as shorter hospital stays compared to those who did not receive antibiotics. In logistic regression analysis, the early administration of carbapenem antibiotics in biliary SAP patients was associated with a lower in-hospital mortality rate. Early antibiotic use in biliary moderate-severe acute pancreatitis (MSAP) reduced hospital stays and in-hospital mortality. Quinolone combined with metronidazole treatment in biliary mild acute pancreatitis (MAP) shortened hospital stays. Early antibiotic use does not benefit patients with non-biliary AP. CONCLUSION: Strategies for antibiotic use in the early stages of AP need to be stratified according to cause and disease severity.

Effect of high-dose intravenous vitamin C therapy on the prognosis in patients with moderately severe and severe acute pancreatitis: protocol of a prospective, randomized, double-blinded, placebo-controlled study.

Introduction: Acute pancreatitis is a common gastrointestinal disease. The mortality of patients affected by severe acute pancreatitis (SAP) remains high. It is unclear whether high-dose intravenous vitamin C (HDIVC) therapy could improve the prognosis of these patients. The current prospective, randomized, double-blinded, placebo-controlled study will explore the effect of high-dose intravenous vitamin C therapy on the prognosis in patients with moderately severe and severe acute pancreatitis. Methods and design: A total of 418 participants with moderately severe and severe acute pancreatitis who meet the eligible criteria will be randomly assigned in a 1:1 ratio to receive treatment with HDIVC (200 mg/kg/24 h) or placebo (saline) for a period of 7 days. The primary outcome is 28-day mortality in these patients. The secondary outcomes include organ functions and interventions, laboratory tests, healthcare, and 90-day mortality. Ethics and dissemination: This protocol was approved by the institutional ethics board of the Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China (Registration Number: 2019-90). The report of the study will be published in peer-reviewed journals and presented at conferences, both nationally and internationally. Clinical trial registration: Chinese Clinical Trial Registry (ChiCTR1900022022). Version 1.5.

Early short-term abdominal paracentesis drainage in moderately severe and severe acute pancreatitis with pelvic ascites.

BACKGROUND: We sought to evaluate the effect of early short-term abdominal paracentesis drainage (APD) in moderately severe and severe acute pancreatitis (MSAP/SAP) with pelvic ascites. METHODS: A total of 135 MSAP/SAP patients with early pelvic ascites were divided into the Short-term APD group (57 patients) and the Non-APD group (78 patients). The effects, complications, and prognosis of short-term APD patients were evaluated. RESULTS: The baseline characteristics in the two groups were similar. The target days of intra-abdominal hypertension relief, half-dose enteral nutrition, duration of mechanical ventilation, length of intensive care unit stay (in days) and total hospitalization (also in days) were all lower in the Short-term APD group than in the Non-APD group (P = 0.002, 0.009, 0.004, 0.006 and 0.019), while the white blood cell count and serum C-reaction protein level decreased significantly more quickly (P < 0.01 and P < 0.05), and the prevalence of intra-abdominal infection was also significantly lower (P = 0.014) in the former than the latter. No complications occurred in early APD patients, and the microbial cultures of pelvic ascites were all negative. In addition, patients with early APD presented fewer cases of residual wall-off necrosis or fluid collection (P = 0.008) at discharge and had a lower incidence of rehospitalization and percutaneous catheter drainage and/or necrosectomy (P = 0.017 and 0.009). CONCLUSIONS: For MSAP/SAP patients with pelvic ascites, the early short-term APD is feasible and safe to perform, and it can decrease clinical symptoms, reduce intra-abdominal infection and shorten the hospital stay. It may also reduce the incidence of rehospitalization and surgical intervention.

Prognostic Accuracy of the Different Scoring Systems for Assessing Coagulopathy in Sepsis: A Retrospective Study.

There is no gold standard for the diagnosis of coagulation dysfunction in sepsis, and the use of the current scoring systems is still controversial. The purpose of this study was to assess the performance of sepsis-induced coagulopathy (SIC), the Japanese Association for Acute Medicine Disseminated Intravascular Coagulation (JAAM DIC), and the International Society on Thrombosis and Haemostasis overt DIC (ISTH overt-DIC). The relationship between each scoring system and 28-day all-cause mortality was examined. Among 452 patients (mean age, 65 [48,76] years), 306 [66.7%] were men, the median SOFA score was 6 [4,9], and the median APACHE II score was 15 [11,22]. A total of 132 patients (29.2%) died within 28 days. Both the diagnosis of SIC (AUROC, 0.779 [95% CI, 0.728-0.830], P < 0.001) and ISTH overt-DIC (AUROC, 0.782 [95% CI, 0.732-0.833], P < 0.001) performed equally well in the discrimination of 28-day all-cause mortality (between-group difference: SIC versus ISTH overt-DIC, -0.003 [95% CI, -0.025-0.018], P = 0.766). However, the SIC demonstrated greater calibration for 28-day all-cause mortality than ISTH overt-DIC (the coincidence of the calibration curve of the former is higher than that of the latter). The diagnosis of JAAM DIC was not independently associated with 28-day all-cause mortality in sepsis (RR, 1.115, [95% CI 0.660-1.182], P = 0.684). The SIC scoring system demonstrated superior prognostic prediction ability in comparison with the others and is the most appropriate standard for diagnosing coagulopathy in sepsis.

Different subtypes of nonthyroidal illness syndrome on the prognosis of septic patients: a two-centered retrospective cohort study.

Background: Nonthyroidal illness syndrome (NTIS) is a common endocrine dysfunction predicting unfavorable outcomes in critical illness. The objective of the study is to evaluate the association between different NTIS subtypes with outcomes in septic patients. Methods: Septic patients in two Chinese academic centers from October 2012 and October 2022 are enrolled in analysis. Multivariable regressions are used to assess associations between NTIS and outcomes. Outcomes include in-hospital mortality, length of stay in hospital (LOS), non-invasive ventilation failure and weaning failure. Patients with NTIS are categorized into 4 types according to the different levels of FT4 and TSH. The association between different NTIS subtypes and mortality are further analyzed. Survival curve is plotted using the Kaplan-Meier method. Results: After screening, a total of 1226 septic patients with complete thyroid hormones result are eventually enrolled. Among them, 520 (42.4%) patients are diagnosed as NTIS. In multivariable regression analysis, NTIS is independently associated with increased 30-days mortality (OR=1.759, CI 1.009-3.104, p=0.047), but has no association with 60-days mortality (OR=1.524, CI 0.893-2.618, p=0.123), 90-days mortality (OR=1.411, CI 0.831-2.408, p=0.203), LOS, non-invasive ventilation failure or weaning failure. In NTIS subtypes, NTIS patients with low FT3 and TSH levels, regardless of the FT4 values, have significantly higher mortality than euthyroid patients (30-days mortality, OR= 6.488, CI 1.546-27.808, p=0.01; 60-days mortality, OR=3.973, CI 1.006-15.579, p=0.046; 90-days mortality, OR=3.849, CI 0.977-15.088, p=0.051). This result is consistent in patients with low FT3 and FT4 levels, regardless of the TSH values (30-days mortality, OR=3.349, CI 1.402-7.957, p=0.006; 60-days mortality, OR= 2.594, CI 1.122-5.930, p=0.024; 90-days mortality, OR=2.55, CI 1.110-5.804, p=0.025). There is no survival difference between NTIS patients with low FT3 only and euthyroid patients. Survival plot shows the worst prognosis is in NTIS patients with low FT3, FT4 and TSH level. Conclusions: NTIS is frequent in sepsis. A reduction of FT3 together with FT4 or TSH, but not FT3 only, is associated with an increased risk of mortality.

High-Dose Vitamin C Alleviates Pancreatic Necrosis by Inhibiting Platelet Activation Through the CXCL12/CXCR4 Pathway in Severe Acute Pancreatitis.

Background: Platelet activation in the early stage of pancreatitis is the key step developing into pancreatic necrosis. Studies suggested that vitamin C (Vit C) can inhibit platelet activity by targeting CXCL12/CXCR4 pathway. High-dose Vit C were showed to reduce pancreatic necrosis in severe acute pancreatitis (SAP) but the mechanism remains unclear. Here we speculate high-dose Vit C reduce pancreatic necrosis by inhibiting platelet activation through downregulating CXCL12/CXCR4 pathway. Methods: The pancreatic microcirculation of rats was observed by intravital microscopy. The platelet activity of SAP rats treated with or without high-dose Vit C was analyzed by platelet function test. Besides, the activity of platelets preincubated with high-dose Vit C or vehicle from SAP patients was also evaluated. Then, the TFA (CXCR4 agonist) and rCXCL12 were used to neutralize the effect of high-dose Vit C in SAP rats treated with high-dose Vit C. Meanwhile, the levels of enzymes and inflammatory cytokines in rat plasma, and rats' pancreatic histopathology and mortality were assessed. Results: Platelets from animals and patients with SAP are more sensitive to agonists and are more easily activated. Administration of high-dose Vit C significantly ameliorated excessive activation of platelets in SAP rats, ultimately increasing the microvessel density and inducing microthrombus and blood stasis; these results were consistent with clinical sample analysis. Moreover, high-dose Vit C significantly inhibited the release of amylase, lipase, TNF-α, and IL-6 in SAP rat plasma, reducing pancreatic damage and the mortality of SAP rats. However, using TFA and rCXCL12 significantly reversed the effect of high-dose Vit C on excessive activation of platelets, aggravating microcirculation impairment and pancreatic damage. Conclusion: The present study suggests that high-dose Vit C can ameliorate pancreatic necrosis by improving microcirculation disorders of SAP. For the first time, the underlying mechanism is related with inhibiting platelet activation through the CXCL12/CXCR4 pathway.

Comparison of pathogen detection consistency between metagenomic next-generation sequencing and blood culture in patients with suspected bloodstream infection.

The application of metagenomic next-generation sequencing (mNGS) has gradually been carried out by clinical practitioner. However, few studies have compared it with blood cultures in patients suffering from suspected bloodstream infections. The purpose of this study was to compare the detection of pathogenic microorganisms by these two assays in patients with suspected bloodstream infection. We retrospectively studied patients with fever, chills, antibiotic use for more than 3 days, suspected bloodstream infection, and admission to the emergency department of Ruijin Hospital from January 2020 to June 2022. All patients had blood drawn on the same day for blood mNGS and blood cultures. Clinical and laboratory parameters were collected on the day blood was drawn. The detection of pathogenic microorganisms by the two methods was compared. Risk factors and in-hospital mortality in patients with bloodstream infections were analysed separately for these two assays. In all 99 patients, the pathogenic microorganisms detection rate in blood mNGS was significantly higher than that in blood culture. Blood mNGS was consistent with blood culture in only 12.00% of all positive bacterial and fungal test results. The level of CRP is related to bacteraemia, fungaemia and viraemia detected by blood mNGS. No clear risk factors could be found in patients with a positive blood culture. In critically ill patients, both tests failed to improve patient outcomes. In patients with suspected bloodstream infection, mNGS is not yet a complete replacement for blood cultures.

A senescence-based prognostic gene signature for colorectal cancer and identification of the role of SPP1-positive macrophages in tumor senescence.

Background: Senescence is significantly associated with cancer prognosis. This study aimed to construct a senescence-related prognostic model for colorectal cancer (CRC) and to investigate the influence of senescence on the tumor microenvironment. Methods: Transcriptome and clinical data of CRC cases were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Senescence-related prognostic genes detected by univariate Cox regression were included in Least Absolute Shrinkage and Selection Operator (LASSO) analysis to construct a model. The efficacy of the model was validated using the receiver operating characteristic (ROC) curve and survival analysis. Differentially expressed genes (DEGs) were identified and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed. CIBERSORT and Immuno-Oncology Biological Research (IOBR) were used to investigate the features of the tumor microenvironment. Single-cell RNA-seq data were used to investigate the expression levels of model genes in various cell types. Immunofluorescence staining for p21, SPP1, and CD68 was performed with human colon tissues. Results: A seven-gene (PTGER2, FGF2, IGFBP3, ANGPTL4, DKK1, WNT16 and SPP1) model was finally constructed. Patients were classified as high- or low-risk using the median score as the threshold. The area under the ROC curve (AUC) for the 1-, 2-, and 3-year disease-specific survival (DSS) were 0.731, 0.651, and 0.643, respectively. Survival analysis showed a better 5-year DSS in low-risk patients in the construction and validation cohorts. GO and KEGG analyses revealed that DEGs were enriched in extracellular matrix (ECM)-receptor interactions, focal adhesion, and protein digestion and absorption. CIBERSORT and IOBR analyses revealed an abundance of macrophages and an immunosuppressive environment in the high-risk subgroup. Low-risk patients had higher response rates to immunotherapy than high-risk patients. ScRNA-seq data revealed high expression of SPP1 in a subset of macrophages with strong senescence-associated secretory phenotype (SASP) features. Using CRC tumor tissues, we discovered that SPP1+ macrophages were surrounded by a large number of senescent tumor cells in high-grade tumors. Conclusion: Our study presents a novel model based on senescence-related genes that can identify CRC patients with a poor prognosis and an immunosuppressive tumor microenvironment. SPP1+ macrophages may correlate with cell senescence leading to poor prognosis.

Prognostic performance of the NRS2002, NUTRIC, and modified NUTRIC to identify high nutritional risk in severe acute pancreatitis patients.

Background: Acute pancreatitis (AP) is the most common gastrointestinal disease requiring hospital admission. AP patients are categorized as mild, moderately severe, and severe AP (SAP). For SAP patients, malnutrition increases susceptibility to infection and mortality. The Nutritional Risk Screening 2002 (NRS 2002), the Nutrition Risk in Critically Ill (NUTRIC) score and modified Nutrition Risk in Critically Ill (mNUTRIC) are nutritional risk screening tools of critically ill patients and have not been validated in patients with SAP. It is essential to evaluate the prognostic performance of these nutritional risk screening tools. Materials and methods: A retrospective study was designed to validate the NRS 2002, NUTRIC, and mNUTRIC when applied to SAP patients. Receiver operating characteristic curves were plotted to investigate the predictive ability of clinical outcomes by comparing areas under the curve (AUC). Appropriate cut-offs were calculated by using Youden's index. Patients were identified as being at high nutritional risk according to the calculated cut-off values. The effects of different scoring systems on mortalities were calculated using the Cox proportional hazards model. Logistic regression was used to assess the association between the energy provision and 28-day mortality. Results: From January 2013 to December 2019, 234 SAP patients were included and analyzed. Patients categorized as high nutritional risk by the NRS 2002 (12.6% versus 1.9% for 28-day and 20.5% versus 3.7% for 90-day), NUTRIC (16.2% versus 0.0% for 28-day and 27.0% versus 0.0% for 90-day), and mNUTRIC (16.4% versus 0.0% for 28-day and 26.4% versus 0.8% for 90-day) had significant higher mortality than those categorized as low nutritional risk. The NUTRIC (AUC: 0.861 for 28-day mortality and 0.871 for 90-day mortality, both cut-off value ≥3) and mNUTRIC (AUC: 0.838 for 28-day and 0.828 for 90-day mortality, both cut-off value ≥3) showed better predictive ability of the 28- and 90-day mortality than the NRS 2002 (AUC: 0.706 for 28-day mortality and 0.695 for 90-day mortality, both cut-off value ≥5). Conclusion: The NRS 2002, NUTRIC, and mNUTRIC scores were predictors for the 28- and 90-day mortalities. The NUTRIC and mNUTRIC showed better predictive ability compared with the NRS 2002 when applied to SAP patients.

Altered intestinal microbiome and metabolome correspond to the clinical outcome of sepsis.

BACKGROUND: The gut microbiome plays a pivotal role in the progression of sepsis. However, the specific mechanism of gut microbiota and its metabolites involved in the process of sepsis remains elusive, which limits its translational application. METHOD: In this study, we used a combination of the microbiome and untargeted metabolomics to analyze stool samples from patients with sepsis enrolled at admission, then microbiota, metabolites, and potential signaling pathways that might play important roles in disease outcome were screened out. Finally, the above results were validated by the microbiome and transcriptomics analysis in an animal model of sepsis. RESULTS: Patients with sepsis showed destruction of symbiotic flora and elevated abundance of Enterococcus, which were validated in animal experiments. Additionally, patients with a high burden of Bacteroides, especially B. vulgatus, had higher Acute Physiology and Chronic Health Evaluation II scores and longer stays in the intensive care unit. The intestinal transcriptome in CLP rats illustrated that Enterococcus and Bacteroides had divergent profiles of correlation with differentially expressed genes, indicating distinctly different roles for these bacteria in sepsis. Furthermore, patients with sepsis exhibited disturbances in gut amino acid metabolism compared with healthy controls; namely, tryptophan metabolism was tightly related to an altered microbiota and the severity of sepsis. CONCLUSION: Alterations in microbial and metabolic features in the gut corresponded with the progression of sepsis. Our findings may help to predict the clinical outcome of patients in the early stage of sepsis and provide a translational basis for exploring new therapies.

Clostridioides difficile aggravates dextran sulfate solution (DSS)-induced colitis by shaping the gut microbiota and promoting neutrophil recruitment.

Clostridioides difficile is a pathogen contributing to increased morbidity and mortality of patients with inflammatory bowel disease (IBD). To determine how C. difficile affects the severity of colitis, we constructed a dextran sulfate solution-induced colitis model challenged with C. difficile. Without antibiotic administration, C. difficile led to transient colonization in mice with colitis, but still significantly enhanced disease severity as assessed by weight loss, histopathological damages, and inflammatory cytokine concentrations. Because this effect is independent of toxin production as shown by infection with a non-toxigenic strain, we focused on changes in the gut microbiota. The microbiota altered by C.difficile, featured with reduced proportions of g_Prevotellaceae_UCG-001 and g_Muribaculaceae, were confirmed to contribute to disease severity in colitis mice via fecal microbiota transplantations. The inflamed colon showed neutrophil accumulation by flow cytometric analysis and myeloperoxidase immunochemical staining. There was enrichment of upregulated genes in leukocyte chemotaxis or migration as shown by RNA sequencing analysis. The isolated neutrophils from C. difficile-infected mice with colitis showed a robust migratory ability and had enhanced expression of cytokines and chemokines. We observed a detrimental role of neutrophils in the progress of disease by hindering neutrophil recruitment with the CXCR2 inhibitor SB225002. Furthermore, neutrophil recruitment appeared to be regulated by interleukin (IL)-1ß, as inhibition of IL-1ß production by MCC950 markedly ameliorated inflammation with decreased neutrophil accumulation and neutrophil-derived chemokine expression. In conclusion, our study provides information on the complicated interaction between microbiota and immune responses in C. difficile-induced inflammation in mice with colitis. Our findings could help determine potential therapeutic targets for patients with IBD concurrent with C. difficile infection.

Characteristics and risk factors for extrapancreatic infection in patients with moderate or severe acute pancreatitis.

Background: How to detect acute pancreatitis (AP) complicated with infection early and how to arrange the treatment time are still the main problems in the world. There are few reports on the potential relationship between extrapancreatic infections and AP. The purpose of this article was to investigate the characteristics, influencing factors and prognosis of extrapancreatic infection in AP patients with modified Marshall score ≥2 on admission. Materials and methods: We retrospectively analyzed AP admitted to emergency intensive care unit of Ruijin hospital within 72 h of onset from September 2019 to December 2021. In addition to the patients' baseline data, sites of infection and microorganisms outside the pancreas were collected. Microbial cultures were used to identify infections of the respiratory tract, blood, abdominal cavity, biliary tract, urinary tract and clostridium difficile in feces. Results: 144 patients with AP were included, of which extrapancreatic infection accounted for 40.28%. C-reactive protein, procalcitonin, blood urea nitrogen, serum creatinine, oxygenation index, modified Marshall score, BISAP score and APACHE II score were significantly increased in the extrapancreatic infection group. The risk factors of extrapancreatic infection included blood urea nitrogen, Modified Marshall score and duration of mechanical ventilation. The positive rates of pathogenic bacteria in sputum culture, blood culture, ascites culture and bile culture were significantly higher than those in the 1-3 days after admission. The infection begins to worsen as early as 4-7 days after the onset of symptoms. Extrapancreatic infection is associated with pancreatic necrosis, the rate of laparotomy, length of hospital stay and in-hospital mortality. Conclusion: Our research has confirmed the need to prevent and monitor extrapancreatic infection in the early stage.

Pathogenesis and Therapy of Coagulation Disorders in Severe Acute Pancreatitis.

Ischemia superimposed upon pancreatic edema leads to acute necrotizing pancreatitis. One possible mechanism contributing to ischemia is intravascular thrombogenesis since fibrin deposits have been detected in pancreatic capillaries by electron microscope. Current experimental and clinical data provided compelling evidence that the disorders in the blood coagulation system play a critical role in the pathogenesis of severe acute pancreatitis (SAP). This leads to microcirculatory failure of intra- and extrapancreatic organs and multiple organ failure and increases the case fatality rate. However, the mechanism of coagulopathy underlying SAP is not yet clear, although some anticoagulant drugs have entered clinical practice showing improvement in prognosis. Thus, enhanced understanding of the process might improve the treatment strategies with safety and high efficacy. Herein, the pathogenesis of the coagulation system of SAP was reviewed with a focus on the coagulation pathway, intercellular interactions, and complement system, thereby illustrating some anticoagulant therapies and potential therapeutic targets.