PD-L1 blockade in mitigating severe acute pancreatitis induced pancreatic damage through modulation of immune cell apoptosis.

Acute pancreatitis (AP) is a prevalent gastrointestinal disorder. The immune response plays a crucial role in AP progression. However, the impact of immune regulatory checkpoint PD-L1 on severe acute pancreatitis (SAP) remains uncertain. Hence, this study aimed to examine the influence of PD-L1 on SAP. We assessed PD-L1 expression in neutrophils and monocytes obtained from SAP patients. We induced SAP in C57BL/6J mice, PD-L1 gene-deficient mice, and PD-L1 humanized mice using intraperitoneal injections of cerulein plus lipopolysaccharide. Prior to the initial cerulein injection, a PD-L1 inhibitor was administered. Pancreatic tissues were collected for morphological and immunohistochemical evaluation, and serum levels of amylase, lipase, and cytokines were measured. Flow cytometry analysis was performed using peripheral blood cells. The expression of PD-L1 in neutrophils and monocytes was significantly higher in SAP patients compared to healthy individuals. Likewise, the expression of PD-L1 in inflammatory cells in the peripheral blood of SAP-induced C57BL/6J mice was notably higher than in the control group. In mice with PD-L1 deficiency, SAP model exhibited lower pancreatic pathology scores, amylase, lipase, and cytokine levels compared to wild-type mice. PD-L1 deletion resulted in reduced neutrophil apoptosis, leading to an earlier peak in neutrophil apoptosis. Furthermore, it decreased early monocyte apoptosis and diminished the peak of T lymphocyte apoptosis. Within the SAP model, administration of a PD-L1 inhibitor reduced pancreatic pathology scores, amylase, lipase, and cytokine levels in both C57BL/6J mice and PD-L1 humanized mice. These findings suggest that inhibiting PD-L1 expression can alleviate the severity of SAP.

MyD88 deficiency aggravates the severity of acute pancreatitis by promoting MyD88-independent TRIF pathway-mediated necrosis.

Background: With uncontrolled inflammatory progression, acute pancreatitis (AP) can progress to severe acute pancreatitis (SAP). Inflammation and parenchymal cell death are key pathologic responses of AP. Toll-like receptor 4 (TLR4) plays a pro-inflammatory role in AP. Myeloid differentiation primary response protein 88 (MyD88) is the most essential utilized adaptor of TLR4, but its role in AP remains unclear. We investigated the potential role of MyD88 in the pathogenesis of AP. Methods: An AP model was induced by administering either cerulein or L-arginine to wild-type or MyD88-deficient mice. Additionally, receptor-interacting protein kinase 1 (RIP1) inhibitor necrostatin-1 (Nec-1) was administered to the MyD88-/- mice. The severity of AP was determined by measuring serum amylase and lipase activities, quantifying pancreatic myeloperoxidase (MPO) activity, and histological examination. The effects of MyD88 deletion on cell death and the inflammatory response were determined by measuring apoptosis, necrosis, and inflammatory cytokines. Western blot was used to assess the necrotic mediators, RIP1 and RIP3. Results: The deletion of MyD88 resulted in more severe acute experimental pancreatitis as assessed by increased amylase and lipase activities, increased pancreatic MPO activity, a reduced anti-inflammatory response, reduced apoptosis, and increased necrosis. Additionally, Nec-1 treatment significantly reduced necrosis in the MyD88-/- mice. Conclusions: The deletion of MyD88 inhibited the TLR4/MyD88-dependent pathway mediated protective immune defense response and enhanced TLR4/MyD88-independent TRIF pathway-mediated pancreatic necrosis, which in turn aggravated the severity of AP. The critical role of MyD88 in immune defense response and cell death indicates that MyD88 represents a potential therapeutic target in the management of AP.

Development and validation of a prediction model for moderately severe and severe acute pancreatitis in pregnancy.

BACKGROUND: The severity of acute pancreatitis in pregnancy (APIP) is correlated with higher risks of maternal and fetal death. AIM: To develop a nomogram that could predict moderately severe and severe acute pancreatitis in pregnancy (MSIP). METHODS: Patients with APIP admitted to West China Hospital between January 2012 and December 2018 were included in this study. They were divided into mild acute pancreatitis in pregnancy (MAIP) and MSIP. Characteristic parameters and laboratory results were collected. The training set and test set were randomly divided at a ratio of 7:3. Least absolute shrinkage and selection operator regression was used to select potential prognostic factors. A nomogram was developed by logistic regression. A random forest model was used to validate the stability of the prediction factors. Receiver operating characteristic curves and calibration curves were used to evaluate the model's predictive performance. RESULTS: A total of 190 patients were included in this study. A total of 134 patients (70.5%) and 56 patients (29.5%) were classified as having MAIP and MSIP, respectively. Four independent predictors (lactate dehydrogenase, triglyceride, cholesterol, and albumin levels) were identified for MSIP. A nomogram prediction model based on these factors was established. The model had areas under the curve of 0.865 and 0.853 in the training and validation sets, respectively. The calibration curves showed that the nomogram has a good consistency. CONCLUSION: A nomogram including lactate dehydrogenase, triglyceride, cholesterol, and albumin levels as independent predictors was built with good performance for MSIP prediction.

Development and validation of a prediction model for deep vein thrombosis in older non-mild acute pancreatitis patients.

BACKGROUND: Deep vein thrombosis (DVT) may cause pulmonary embolus, leading to late deaths. The systemic inflammatory and hypercoagulable state of moderate and severe acute pancreatitis (non-mild acute pancreatitis, NMAP) patients may contribute to the development of venous thromboembolism. Accurate prediction of DVT is conducive to clinical decisions. AIM: To develop and validate a potential new prediction nomogram model for the occurrence of DVT in NMAP. METHODS: NMAP patient admission between 2013.1.1 and 2018.12.31 at the West China Hospital of Sichuan University was collected. A total of 220 patients formed the training set for nomogram development, and a validation set was constructed using bootstrapping with 100 resamplings. Univariate and multivariate logistic regression analyses were used to estimate independent risk factors associated with DVT. The independent risk factors were included in the nomogram. The accuracy and utility of the nomogram were evaluated by calibration curve and decision curve analysis, respectively. RESULTS: A total of 220 NMAP patients over 60 years old were enrolled for this analysis. DVT was detected in 80 (36.4%) patients. The final nomogram included age, sex, surgery times, D-dimer, neutrophils, any organ failure, blood culture, and classification. This model achieved good concordance indexes of 0.827 (95%CI: 0.769-0.885) and 0.803 (95%CI: 0.743-0.860) in the training and validation sets, respectively. CONCLUSION: We developed and validated a prediction nomogram model for DVT in older patients with NMAP. This may help guide doctors in making sound decisions regarding the administration of DVT prophylaxis.

Total pancreatectomy compared with pancreaticoduodenectomy: a systematic review and meta-analysis.

Aim: To assess whether total pancreatectomy (TP) is as feasible, safe, and efficacious as pancreaticoduodenectomy (PD). Materials and Methods: Major databases, including PubMed, EMBASE, Science Citation Index Expanded, Scopus and the Cochrane Library, were searched for studies comparing TP and PD between January 1943 and June 2018. The meta-analysis only included studies that were conducted after 2000. The primary outcomes were morbidity and mortality. Pooled odds ratios (ORs), weighted mean differences (WMDs) or hazard ratios (HRs) with 95 percent confidence intervals (CIs) were calculated using fixed effects or random effects models. The methodological quality of the included studies was evaluated by the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. Results: In total, 45 studies were included in this systematic review, and 5 non-randomized comparative studies with 786 patients (TP: 270, PD: 516) were included in the meta-analysis. There were no differences in terms of mortality (OR: 1.44, 95% CI: 0.66-3.16; P=0.36), hospital stay (WMD: -0.60, 95% CI: -1.78-0.59; P=0.32) and rates of reoperation (OR: 1.12; 95% CI: 0.55-2.31; P=0.75) between the two groups. In addition, morbidity was not significantly different between the two groups (OR: 1.41, 95% CI: 1.01-1.97; P=0.05); however, the results showed that the TP group tended to have more complications than the PD group. Furthermore, the operation time (WMD: 29.56, 95% CI: 8.23-50.89; P=0.007) was longer in the TP group. Blood loss (WMD: 339.96, 95% CI: 117.74-562.18; P=0.003) and blood transfusion (OR: 4.86, 95% CI: 1.93-12.29; P=0.0008) were more common in the TP group than in the PD group. There were no differences in the long-term survival rates between the two groups. Conclusion: This systematic review and meta-analysis suggested that TP may not be as feasible and safe as PD. However, TP and PD may have the same efficacy.

The oncological safety in minimally invasive versus open distal pancreatectomy for pancreatic ductal adenocarcinoma: a systematic review and meta-analysis.

The safety of minimally invasive distal pancreatectomy (MIDP) and open distal pancreatectomy (ODP) regarding oncological outcomes of pancreatic ductal adenocarcinoma (PDAC) remains inconclusive. Therefore, the aim of this study was to examine the oncological safety of MIDP and ODP for PDAC. Major databases including PubMed, Embase, Science Citation Index Expanded, and the Cochrane Library were searched for studies comparing outcomes in patients undergoing MIDP and ODP for PDAC from January 1994 to August 2018. In total, 11 retrospective comparative studies with 4829 patients (MIDP: 1076, ODP: 3753) were included. The primary outcome was long-term survival, including 3-year overall survival (OS) and 5-year OS. The 3-year OS (hazard ratio (HR): 1.03, 95% confidence interval (CI): 0.89, 1.21; P = 0.66) and 5-year OS (HR: 0.91, 95% CI: 0.65, 1.28; P = 0.59) showed no significant differences between the two groups. Furthermore, the positive surgical margin rate (weighted mean difference (WMD): 0.71, 95% CI: 0.56, 0.89, P = 0.003) was lower in the MIDP group. However, patients in the MIDP group had less intraoperative blood loss (WMD: -250.03, 95% CI: -359.68, -140.39; P < 0.00001), a shorter hospital stay (WMD: -2.76, 95% CI: -3.73, -1.78; P < 0.00001) and lower morbidity (OR: 0.57, 95% CI: 0.46, 0.71; P < 0.00001) and mortality (OR: 0.50, 95% CI: 0.31, 0.81, P = 0.005) than patients in the ODP group. The limited evidence suggested that MIDP might be safer with regard to oncological outcomes in PDAC patients. Therefore, future high-quality studies are needed to examine the oncological safety of MIDP.

Timing of Laparoscopic Cholecystectomy After Mild Biliary Pancreatitis: A Systematic Review and Meta-Analysis.

AIM: To compare the safety of cholecystectomy in early laparoscopic cholecystectomy (ELC) and delayed laparoscopic cholecystectomy (DLC). METHODS: We systematically searched PubMed, EMBASE, and Cochrane Library for studies that were published from January 1992 to March 2017. We included studies on patients with mild biliary pancreatitis and that reported the timing of cholecystectomy and the number of complications, readmissions, and conversion to open cholecystectomy. Moreover, we assessed the quality and bias risks of the included studies. RESULTS: After screening 4651 studies, we included 3 randomized clinical trials and 10 retrospective studies. The included studies described 2291 patients, of whom 1141 (49.8%) underwent ELC and 1150 (50.2%) underwent DLC. The reported rate of complications for ELC (6.8%) was lower than that for DLC (13.45%). The reported rate of readmission for ELC was lower than that for DLC. The length of hospital stay was longer with DLC than with ELC. ELC and DLC did not have significantly different rates of conversion to open cholecystectomy and duration of surgery. CONCLUSION: This meta-analysis provides evidence that ELC is better than DLC in many aspects for acute mild pancreatitis patients undergoing laparoscopic cholecystectomy. ELC associated with few complications and readmissions, as well as a short length of hospital stay.