Angiopoietin-2 Is an Early Predictor for Acute Gastrointestinal Injury and Intestinal Barrier Dysfunction in Patients with Acute Pancreatitis

Immune markers of severe acute pancreatitis

PURPOSE OF REVIEW

Acute pancreatitis is a common acute inflammatory disorder of the pancreas, and its incidence has been increasing worldwide. Approximately 10% of acute pancreatitis progresses to severe acute pancreatitis (SAP), which carries significant morbidity and mortality. Disordered immune response to pancreatic injury is regarded as a key event that mediates systemic injury in SAP. In this article, we review recent developments in immune biomarkers of SAP and future directions for research.

RECENT FINDINGS

Given the importance of the NLRP3-inflammasome pathway in mediating systemic inflammatory response syndrome and systemic injury, recent studies have investigated associations of SAP with systemic levels of activators of NLRP3, such as the damage associated molecular patterns (DAMPs) for the first time in human SAP. For example, circulating levels of histones, mitochondrial DNAs, and cell free DNAs have been associated with SAP. A panel of mechanistically relevant immune markers (e.g., panel of Angiopoeitin-2, hepatocyte growth factor, interleukin-8 (IL-8), resistin and sTNF-α R1) carried higher predictive accuracies than existing clinical scores and individual immune markers. Of the cytokines with established relevance to SAP pathogenesis, phase 2 trials of immunotherapies, including tumor necrosis factor (TNF)-alpha inhibition and stimulation of IL-10 production, are underway to determine if altering the immunologic response can reduce the severity of acute pancreatitis (AP).

SUMMARY

Circulating systemic levels of various DAMPs and a panel of immune markers that possibly reflect activities of different pathways that drive SAP appear promising as predictive biomarkers for SAP. But larger multicenter studies are needed for external validation. Studies investigating immune cellular pathways driving SAP using immunophenotyping techniques are scarce. Interdisciplinary efforts are also needed to bring some of the promising biomarkers to the bedside for validation and testing for clinical utility. Studies investigating the role of and characterization of altered gut-lymph and gut-microbiota in severe AP are needed.

Silencing ANGPT2 alleviates ulcerative colitis by regulating autophagy-mediated NLRP3 inflammasome inactivation via the mTOR signaling pathway

Ulcerative colitis (UC) is a difficult intestinal disease characterized by inflammation, and its mechanism is complex and diverse. Angiopoietin-like protein 2 (ANGPT2) plays an important regulatory role in inflammatory diseases. However, the role of ANGPT2 in UC has not been reported so far. After exploring the expression level of ANGPT2 in serum of UC patients, the reaction mechanism of ANGPT2 was investigated in dextran sodium sulfate (DSS)-induced UC mice. After ANGPT2 expression was suppressed, the clinical symptoms and pathological changes of UC mice were detected. Colonic infiltration, oxidative stress, and colonic mucosal barrier in UC mice were evaluated utilizing immunohistochemistry, immunofluorescence, and related kits. Finally, western blot was applied for the estimation of mTOR signaling pathway and NLRP3 inflammasome-related proteins. ANGPT2 silencing improved clinical symptoms and pathological changes, alleviated colonic inflammatory infiltration and oxidative stress, and maintained the colonic mucosal barrier in DSS-induced UC mice. The regulatory effect of ANGPT2 on UC disease might occur by regulating the mTOR signaling pathway and thus affecting autophagy-mediated NLRP3 inflammasome inactivation. ANGPT2 silencing alleviated UC by regulating autophagy-mediated NLRP3 inflammasome inactivation via the mTOR signaling pathway.

The Predictive Value of Serum DAO, HDC, and MMP8 for the Gastrointestinal Injury in the Early Stage of Acute Pancreatitis in an Animal Model and a Clinical Study

Purpose

This study was aimed at exploring the use of the acute gastrointestinal injury (AGI) grade and sensitive biomarkers to investigate gastrointestinal (GI) injury in early stage of acute pancreatitis (AP).

Patients and Methods

The AGI grade was used to evaluate intestinal function. Any GI injury above grade I (grades II-IV) was considered as severe. An AP rat model was created by retrograde injection of 4% sodium taurocholate. The pancreatic and intestinal histopathology scores were calculated by hematoxylin-eosin staining. Human and rat sera were assessed using ELISA. Tight junction (TJ) proteins were detected by Western blotting.

Results

In clinical study, the GI injury rate in mild acute pancreatitis (MAP), moderate severe acute pancreatitis (MSAP), and severe acute pancreatitis (SAP) groups was 26.8%, 78.4%, and 94.8%, respectively (P < 0.05). Diamine oxidase (DAO), histidine decarboxylase (HDC), and matrix metalloproteinase 8 (MMP8) serum levels were higher in AP patients than in healthy people (P < 0.05). Patients with GI injury had higher serum levels of DAO, HDC, and MMP8 than those without GI injury (P < 0.05). In animal experiments, the serum levels of DAO, HDC, and MMP8 were higher in the AP group than in normal and sham-operated (SO) groups (P < 0.05). The expressions of tricellulin, claudin-1, ZO-1, and occludin were significantly lower in the AP group than in normal and SO groups (P < 0.05).

Conclusion

The serum levels of DAO, HDC, and MMP8 are novel biomarkers of GI injury in the early stage of AP; their elevation indicates the development of GI injury in AP. The intestinal TJ disruption may be a primary mechanism of GI injury and requires more in-depth research.

Fabp5 is a common gene between a high-cholesterol diet and acute pancreatitis

Background and aims

Hypercholesterolemia has been identified as risk factor for severe acute pancreatitis (AP). We aimed to identify the common differentially expressed genes (DEGs) between a high-cholesterol diet and AP.

Methods

We retrived gene expression profiles from the GEO database. DEGs were assessed using GEO2R. For AP hub genes, we conducted functional enrichment analysis and protein-protein interaction (PPI) analysis. GeneMANIA and correlation analysis were employed to predict potential DEG mechanisms. Validation was done across various healthy human tissues, pancreatic adenocarcinoma, peripheral blood in AP patients, and Sprague-Dawley rats with AP.

Results

The gene "Fabp5" emerged as the sole common DEG shared by a high-cholesterol diet and AP. Using the 12 topological analysis methods in PPI network analysis, Rela, Actb, Cdh1, and Vcl were identified as hub DEGs. GeneMANIA revealed 77.6% physical interactions among Fabp5, TLR4, and Rela, while genetic correlation analysis indicated moderate associations among them. Peripheral blood analysis yielded area under the ROC curve (AUC) values of 0.71, 0.63, 0.74, 0.64, and 0.91 for Fabp5, TLR4, Actb, Cdh1 genes, and artificial neural network (ANN) model respectively, in predicting severe AP. In vivo immunohistochemical analysis demonstrated higher Fabp5 expression in the hyperlipidemia-associated AP group compared to the AP and control groups.

Conclusion

Fabp5 emerged as the common DEG connecting a high-cholesterol diet and AP. Rela was highlighted as a crucial hub gene in AP. Genetic interactions were observed among Fabp5, TLR4, and Rela. An ANN model consisting of Fabp5, TLR4, Actb, and Cdh1 was helpful in predicting severe AP.

Inhibition of angiotensin II type 1 receptor reduces oxidative stress damage to the intestinal barrier in severe acute pancreatitis

Intestinal barrier injury is a common complication of severe acute pancreatitis (SAP), which is often accompanied by intestinal mucosal barrier injury and results in serious consequences. However, the exact mechanism remains unclear. We aimed to investigate whether angiotensin II type 1 receptor (AT1)-mediated oxidative stress is involved in SAP intestinal barrier injury and assessed the effects of inhibiting this pathway. The SAP model was established by retrograde bile duct injection of sodium taurocholate (5%). The rats were divided into three groups: the control group (SO), the SAP group (SAP), and the azilsartan intervention group (SAP + AZL). Serum amylase, lipase, and other indexes were measured to evaluate SAP severity in each group. Histopathological changes in the pancreas and intestine were evaluated by HE staining. The oxidative stress of intestinal epithelial cells was detected by superoxide dismutase and glutathione. We also detected the expression and distribution of intestinal barrier-related proteins. The results showed that the serum indexes, the severity of tissue damage, and the level of oxidative stress in the SAP + AZL group were significantly lower than in the SAP group. Our study provided hitherto undocumented evidence of AT1 expression in the intestinal mucosa, confirming that AT1-mediated oxidative stress is involved in SAP intestinal mucosal injury, and inhibiting this pathway could effectively reduce intestinal mucosal oxidative stress injury, providing a new and effective target for the treatment of SAP intestinal barrier injury.

External use of mirabilite to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis in children: A multicenter randomized controlled trial

BACKGROUND

Acute pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography (ERCP). Currently, there is no suitable treatment for post-ERCP pancreatitis (PEP) prophylaxis. Few studies have prospectively evaluated interventions to prevent PEP in children.

AIM

To assess the efficacy and safety of the external use of mirabilite to prevent PEP in children.

METHODS

This multicenter, randomized controlled clinical trial enrolled patients with chronic pancreatitis scheduled for ERCP according to eligibility criteria. Patients were randomly divided into the external use of mirabilite group (external use of mirabilite in a bag on the projected abdominal area within 30 min before ERCP) and blank group. The primary outcome was the incidence of PEP. The secondary outcomes included the severity of PEP, abdominal pain scores, levels of serum inflammatory markers [tumor necrosis factor-alpha (TNF-α) and serum interleukin-10 (IL-10)], and intestinal barrier function markers [diamine oxidase (DAO), D-lactic acid, and endotoxin]. Additionally, the side effects of topical mirabilite were investigated.

RESULTS

A total of 234 patients were enrolled, including 117 in the external use of mirabilite group and the other 117 in the blank group. The pre-procedure and procedure-related factors were not significantly different between the two groups. The incidence of PEP in the external use of mirabilite group was significantly lower than that in the blank group (7.7% vs 26.5%, P < 0.001). The severity of PEP decreased in the mirabilite group (P = 0.023). At 24 h after the procedure, the visual analog scale score in the external use of mirabilite group was lower than that in the blank group (P = 0.001). Compared with those in the blank group, the TNF-α expressions were significantly lower and the IL-10 expressions were significantly higher at 24 h after the procedure in the external use of mirabilite group (P = 0.032 and P = 0.011, respectively). There were no significant differences in serum DAO, D-lactic acid, and endotoxin levels before and after ERCP between the two groups. No adverse effects of mirabilite were observed.

CONCLUSION

External use of mirabilite reduced the PEP occurrence. It significantly alleviated post-procedural pain and reduced inflammatory response. Our results favor the external use of mirabilite to prevent PEP in children.

[Association between coagulation function and prognosis in patients with acute pancreatitis]

OBJECTIVE

To explore the correlation of coagulation function with the severity and prognosis of acute pancreatitis (AP) and identify the laboratory markers for early prediction and dynamic monitoring of the prognosis of AP.

METHODS

We retrospectively analyzed the clinical data of patients with AP admitted less than 72 h after onset to our hospital from December 1, 2017 to November 30, 2018. The correlation of coagulation function-related markers at admission and their changes during hospitalization with the prognosis of the patients was analyzed.

RESULTS

We screened the data of a total of 1260 patients with AP against the inclusion and exclusion criteria, and eventually 175 patients were enrolled in this analysis, among whom 52 patients had severe AP (SAP) and 12 patients died. Logistic regression analysis identified vWF: Ag, PT, PC, AT Ⅲ and D-dimer markers at admission as independent risk factors for predicting SAP and death. Dynamic monitoring of the changes in coagulation function-related markers in the disease course had greater predictive value of the patients' prognosis, and the indicators including vWF: Ag_max, PT_max, APTT_max, TT_max, FIB_min, D-dimer_max, PLT_min, PC_min, PLG_min, AT Ⅲ_min, and their variations were all independent risk factors for predicting SAP and death. ROC analysis suggested that dynamic monitoring of the changes in the indicators, especially those of △vWF: Ag, △PT, △APTT, △FIB, △TT, △D-dimer, △PLT, △PC, △AT Ⅲ, △PLG, could effectively predict SAP and death in these patients (with AUC range of 0.63-0.84).

CONCLUSION

Patients with AP have vascular endothelial injuries and coagulation disorders. The markers including vWF: Ag, PT, PC, AT Ⅲ and D-dimer at admission are independent risk factors for predicting SAP and death, and dynamic monitoring of the changes in vWF: Ag、PT、APTT、TT、FIB、D-dimer、PLT、PC、AT Ⅲ and PLG can further increase the predictive value.

Predicting the Need for Therapeutic Intervention and Mortality in Acute Pancreatitis: A Two-Center International Study Using Machine Learning

Background: Current approaches to predicting intervention needs and mortality have reached 65–85% accuracy, which falls below clinical decision-making requirements in patients with acute pancreatitis (AP). We aimed to accurately predict therapeutic intervention needs and mortality on admission, in AP patients, using machine learning (ML). Methods: Data were obtained from three databases of patients admitted with AP: one retrospective (Chengdu) and two prospective (Liverpool and Chengdu) databases. Intervention and mortality differences, as well as potential predictors, were investigated. Univariate analysis was conducted, followed by a random forest ML algorithm used in multivariate analysis, to identify predictors. The ML performance matrix was applied to evaluate the model’s performance. Results: Three datasets of 2846 patients included 25 potential clinical predictors in the univariate analysis. The top ten identified predictors were obtained by ML models, for predicting interventions and mortality, from the training dataset. The prediction of interventions includes death in non-intervention patients, validated with high accuracy (96%/98%), the area under the receiver-operating-characteristic curve (0.90/0.98), and positive likelihood ratios (22.3/69.8), respectively. The post-test probabilities in the test set were 55.4% and 71.6%, respectively, which were considerably superior to existing prognostic scores. The ML model, for predicting mortality in intervention patients, performed better or equally with prognostic scores. Conclusions: ML, using admission clinical predictors, can accurately predict therapeutic interventions and mortality in patients with AP.

[Etiology and pathogenesis of infected pancreatic necrosis]

Modern literature data confirm the central role of intestinal barrier complex not only as a target in acute necrotizing pancreatitis, but also as a trigger for septic complications. Intra-abdominal hypertension, endothelial dysfunction and gut microbiome changes following necrotizing pancreatitis might have an independent impact on acute intestinal distress syndrome and bacterial translocation. Monitoring of these conditions and early target therapy can improve the outcomes in patients with severe acute pancreatitis. Adverse outcomes of infected pancreatic necrosis including high mortality and morbidity are largely due to the prevalence of multidrug-resistant bacterial pathogens.

Angiopoietin-2 silence alleviates lipopolysaccharide-induced inflammation, barrier dysfunction and endoplasmic reticulum stress of intestinal epithelial cells by blocking Notch signaling pathway

Necrotizing enterocolitis, a devastating gastrointestinal disease with high mortality, poses great threats to global health. Therefore, we conducted this study to explore the role of ANGPT2, as well as the potential mechanism, in necrotizing enterocolitis. IEC-6 cells were stimulated with lipopolysaccharide (LPS) to induce necrotizing enterocolitis model in vitro. The expression of ANGPT2 was measured by RT-qPCR. The cell viability was detected using CCK-8. Besides, the expressions of endoplasmic reticulum (ER) stress-related proteins, Notch signaling pathway-related proteins and tight junction proteins were checked by western blot. The apoptosis and inflammatory response were detected by TUNEL and ELISA, respectively. Moreover, with the adoption of TEER, the cell monolayer permeability was detected. The results showed that ANGPT2 expression was greatly increased after LPS induction. In addition, ANGPT2 knockdown significantly decreased the apoptosis, inflammatory response, barrier dysfunction and endoplasmic reticulum stress of LPS-induced IEC-6 cells. What is more, ANGPT2 knockdown could block Notch signaling pathway. Additionally, with the treatment of Jagged-1, the protective effect of ANGPT2 knockdown on LPS-induced intestinal injury was partly abolished. To sum up, silencing ANGPT2 could improve LPS-induced inflammation, barrier dysfunction and ER stress of intestinal epithelial cells via blocking Notch signaling pathway.

Nutritional Support in Patients with Severe Acute Pancreatitis-Current Standards

Severe acute pancreatitis (SAP) leads to numerous inflammatory and nutritional disturbances. All SAP patients are at a high nutritional risk. It has been proven that proper nutrition significantly reduces mortality rate and the incidence of the infectious complications in SAP patients. According to the literature, early (started within 24-48 h) enteral nutrition (EN) is optimal in most patients. EN protects gut barrier function because it decreases gastrointestinal dysmotility secondary to pancreatic inflammation. Currently, the role of parenteral nutrition (PN) in SAP patients is limited to patients in whom EN is not possible or contraindicated. Early versus delayed EN, nasogastric versus nasojejunal tube for EN, EN versus PN in SAP patients and the role of immunonutrition (IN) in SAP patients are discussed in this review.

Accuracy of angiopoietin-2 for predicting organ failure in patients with acute pancreatitis: a systematic review and meta-analysis

Objective

Our aim was to assess the accuracy of angiopoietin-2 (Ang-2) as a prognostic marker for acute pancreatitis (AP) with organ failure (OF).

Methods

We undertook a systematic search of the PubMed, Cochrane Library, Embase, Chinese Journals Full-text, Wanfang, China Biology Medicine disc, and Weipu databases to identify eligible cohort studies on the predictive value of Ang-2 for AP with OF. The main outcome measures were sensitivity and specificity. The effects were pooled using a bivariate mixed-effects model.

Results

Six articles with seven case-control studies (n = 650) were included. Pooled sensitivity, specificity, and positive and negative likelihood ratios with 95% confidence intervals (CI) for AP with OF were 0.93 (95%CI: 0.75–0.99), 0.85 (95%CI: 0.75–0.92), 6.40 (95%CI: 3.36–12.19), and 0.08 (95%CI: 0.02–0.36), respectively. The area under the summary receiver operating characteristic curve was 0.95 (95%CI: 0.92–0.96), and the diagnostic odds ratio was 83.18 (95%CI: 11.50–623.17). Subgroup analysis showed that admission time of AP onset (< or ≥24 hours) was a source of overall heterogeneity. Sensitivity analysis supported this finding.

Conclusion

Ang-2 had high diagnostic accuracy for AP with OF; the best prediction of Ang-2 may be 24 to 72 hours after onset of AP.

Management of Severe Acute Pancreatitis

Purpose of review

There have been significant advancements in different aspects of management of severe acute pancreatitis (SAP). Our review of the most recent literature focuses on severity prediction, fluid resuscitation, analgesic administration, nutrition, and endoscopic intervention for SAP and its extra-pancreatic complications.

Recent findings

Recent studies on serum cytokines for the prediction of SAP have shown superior prognostic performance when compared with conventional laboratory tests and clinical scoring systems. In patients with established SAP and vascular leak syndrome, intravenous fluids should be administered with caution to prevent intra-abdominal hypertension and volume overload. Endoscopic retrograde cholangiopancreatography improves outcomes only in AP patients with suspected cholangitis. Early enteral tube-feeding does not appear to be superior to on-demand oral feeding. Abdominal compartment syndrome is a highly lethal complication of SAP that requires percutaneous drainage or decompressive laparotomy. Endoscopic transmural drainage followed by necrosectomy (i.e., “step-up approach”) is the treatment strategy of choice in patients with symptomatic or infected walled-off pancreatic necrosis.

Summary

SAP is a complex clinical syndrome associated with a high mortality rate. Early prediction of SAP remains challenging due to the limited accuracy of the available prediction tools. Early fluid resuscitation, organ support, enteral nutrition, and prevention of/or prompt recognition of abdominal compartment syndrome remain cornerstones of its management. A step-up, minimally invasive drainage/debridement is the preferred approach for patients with infected pancreatic necrosis.

Overview and prospect of serum markers for early prediction of severity of acute pancreatitis

Acute pancreatitis (AP) is one of the most common and potentially fatal emergencies of the digestive system. Aseptic inflammation of the pancreas caused by self-digestion of trypsin is considered to be the main pathogenesis of AP. The clinical course and prognosis of AP with different degrees of severity vary greatly, so early prediction of the severity of AP is of great significance to the diagnosis and treatment of this disease. In recent years, great progress has been made in the early risk assessment and severity stratification of AP patients with serum markers. This article gives an overview and discuss the prospects of serum markers for early prediction of the severity of AP.