Management of infected pancreatic necrosis in the intensive care unit: a narrative review

Emphysematous Pancreatitis as a Life-Threatening Condition: A Case Report and Review of the Literature

Emphysematous pancreatitis represents the presence of gas within or around the pancreas on the ground of necrotizing pancreatitis due to superinfection with gas-forming bacteria. This entity is diagnosed on clinical grounds and on the basis of radiologic findings. Computed tomography is the preferred imaging modality used to detect this life-threating condition. The management of emphysematous pancreatitis consists of conservative measures, image-guided percutaneous catheter drainage or endoscopic therapy, and surgical intervention, which is delayed as long as possible and undertaken only in patients who continue to deteriorate despite conservative management. Due to its high mortality rate, early and prompt recognition and treatment of emphysematous pancreatitis are crucial and require individualized treatment with the involvement of a multidisciplinary team. Here, we present a case of emphysematous pancreatitis as an unusual occurrence and discuss disease features and treatment options in order to facilitate diagnostics and therapy.

Dynamic nomogram for predicting infected pancreatic necrosis in female patients of childbearing age with hypertriglyceridemia-induced acute pancreatitis

BACKGROUND

Hypertriglyceridemia is a common cause of acute pancreatitis. Pregnant women are at risk of developing hypertriglyceridemia-induced acute pancreatitis (HTG-AP); however, whether pregnancy increases the risk of infected pancreatic necrosis (IPN) is unknown.

AIM

We aimed to assess the association between pregnancy and IPN.

METHODS

This 10-year retrospective cohort study was conducted at Jinling Hospital. Adult female patients of childbearing age with HTG-AP between January 2013 and September 2022 were screened. Logistic regression analyses were performed to assess the risk factors for IPN. Patients admitted within 7 days were assigned to the training and validation sets to develop a dynamic nomogram for IPN prediction.

RESULTS

489 patients were included, and 144 developed IPN. Logistic regression analyses revealed pregnancy (OR: 2.578 95% CI: 1.474-4.510) as an independent risk factor for IPN. Gestation weeks, ARDS, albumin level, and serum creatinine level were selected as the predictors of the dynamic nomogram for IPN prediction, with good discrimination in the training set (AUC 0.867 95% CI: 0.794-0.940) and validation set (AUC 0.957 95% CI: 0.885-1.000).

CONCLUSION

Pregnancy increases the risk of IPN in adult patients of childbearing age with HTG-AP, and the dynamic nomogram may help risk stratification for IPN.

Clinical treatment for persistent inflammation, immunosuppression and catabolism syndrome in patients with severe acute pancreatitis (Review)

Severe acute pancreatitis (SAP) is a severe disease with a high prevalence and a 3-15% mortality worldwide, and premature activation of zymogen for any reason is the initial factor for the onset of SAP. Gallstone disease and heavy alcohol consumption are the two most common etiologies of SAP. Persistent inflammation, immunosuppression and catabolism syndrome (PICS) is a life-threatening illness, and there are no effective treatments. The relapse state of PICS mainly leads to high mortality due to septic shock or severe trauma, both of which are dangerous and challenging conditions for clinicians. Thus, it is important for medical staff to identify patients at high risk of PICS and to master the prevention and treatment of PICS in patients with SAP. The present review aims to increase the understanding of the pathogenesis of PICS, produce evidence for PICS diagnosis and highlight clinical treatment for PICS in patients with SAP. With this information, clinical workers could implement standardized and integrated measures at an early stage of SAP to stop its progression to PICS.

Exploring the regulatory mechanism of tRNA-derived fragments 36 in acute pancreatitis based on small RNA sequencing and experiments

BACKGROUND

Acute pancreatitis (AP) is a disease featuring acute inflammation of the pancreas and histological destruction of acinar cells. Approximately 20% of AP patients progress to moderately severe or severe pancreatitis, with a case fatality rate of up to 30%. However, a single indicator that can serve as the gold standard for prognostic prediction has not been discovered. Therefore, gaining deeper insights into the underlying mechanism of AP progression and the evolution of the disease and exploring effective biomarkers are important for early diagnosis, progression evaluation, and precise treatment of AP.

AIM

To determine the regulatory mechanisms of tRNA-derived fragments (tRFs) in AP based on small RNA sequencing and experiments.

METHODS

Small RNA sequencing and functional enrichment analyses were performed to identify key tRFs and the potential mechanisms in AP. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was conducted to determine tRF expression. AP cell and mouse models were created to investigate the role of tRF36 in AP progression. Lipase, amylase, and cytokine levels were assayed to examine AP progression. Ferritin expression, reactive oxygen species, malondialdehyde, and ferric ion levels were assayed to evaluate cellular ferroptosis. RNA pull down assays and methylated RNA immunoprecipitation were performed to explore the molecular mechanisms.

RESULTS

RT-qPCR results showed that tRF36 was significantly upregulated in the serum of AP patients, compared to healthy controls. Functional enrichment analysis indicated that target genes of tRF36 were involved in ferroptosis-related pathways, including the Hippo signaling pathway and ion transport. Moreover, the occurrence of pancreatic cell ferroptosis was detected in AP cells and mouse models. The results of interference experiments and AP cell models suggested that tRF-36 could promote AP progression through the regulation of ferroptosis. Furthermore, ferroptosis gene microarray, database prediction, and immunoprecipitation suggested that tRF-36 accelerated the progression of AP by recruiting insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) to the p53 mRNA m6A modification site by binding to IGF2BP3, which enhanced p53 mRNA stability and promoted the ferroptosis of pancreatic follicle cells.

CONCLUSION

In conclusion, regulation of nuclear pre-mRNA domain-containing protein 1B promoted AP development by regulating the ferroptosis of pancreatic cells, thereby acting as a prospective therapeutic target for AP. In addition, this study provided a basis for understanding the regulatory mechanisms of tRFs in AP.

Escherichia coli infection indicates favorable outcomes in patients with infected pancreatic necrosis

Introduction

Infected pancreatic necrosis (IPN) is a severe complication of acute necrotizing pancreatitis with increasing morbidity. Escherichia coli is the most frequently cultured microorganism in IPN. However, the implications of Escherichia coli infection on the outcomes of patients with IPN remain unclear. Therefore, this study aimed to evaluate the clinical impacts of Escherichia coli infection on IPN.

Methods

A prospective database with consecutive patients with IPN between January 2010 and April 2022 at a tertiary hospital was post-hoc analyzed. The clinical and microbiological characteristics, surgical management, and follow-up data of patients with and without Escherichia coli infection were compared.

Results

A total of 294 IPN patients were enrolled in this cohort. Compared with non-Escherichia coli infection cases (n=80, 27.2%), patients with Escherichia coli infection (n=214, 72.8%) were characterized by more frequent polymicrobial infections (77.5% vs. 65.0%, P=0.04) but a lower occurrence of severe acute pancreatitis (SAP) (42.5% vs. 61.7%, P=0.003). In addition, significantly lower mortality (12.5% vs. 30.4%, p=0.002), fewer step-up surgical interventions (73.8% vs. 85.1%, P=0.025), and a lower rate of multiple organ failure (MOF) (25.0% vs. 40.2%, P=0.016) were also observed in patients with Escherichia coli infection. Multivariate analysis of mortality predictors indicated that MOF (odds ratio [OR], 6.197; 95% confidence interval [CI], 2.373–16.187; P<0.001) and hemorrhage (OR, 3.485; 95% CI, 1.623–7.487; P=0.001) were independent predictors associated with higher mortality in patients with IPN. Escherichia coli infection was significantly associated with a lower mortality (OR, 0.302; 95% CI, 0.121–0.751; P= 0.01).

Conclusion

Escherichia coli infection indicates a favorable prognosis in patients with IPN, although the mechanism needs further investigation.

Complications Related to Transarterial Treatment of Hepatocellular Carcinoma: A Comprehensive Review

Currently, various types of transarterial treatments are performed for hepatocellular carcinoma from the early to advanced stages. Its indications and efficacy have been widely investigated. However, procedure-related complications have not been updated in the literature, although new types of transarterial treatments, such as drug-eluting bead transarterial chemoembolization and transarterial radioembolization, are common in daily practice. Herein, a comprehensive literature review was carried out, and complications were organized according to the organs affected and treatment modalities.

Activated regulatory T-cells promote duodenal bacterial translocation into necrotic areas in severe acute pancreatitis

OBJECTIVE

In acute pancreatitis (AP), bacterial translocation and subsequent infection of pancreatic necrosis are the main risk factors for severe disease and late death. Understanding how immunological host defence mechanisms fail to protect the intestinal barrier is of great importance in reducing the mortality risk of the disease. Here, we studied the role of the T_reg/Th17 balance for maintaining the intestinal barrier function in a mouse model of severe AP.

DESIGN

AP was induced by partial duct ligation in C57Bl/6 or DEREG mice, in which regulatory T-cells (T_reg) were depleted by intraperitoneal injection of diphtheria toxin. By flow cytometry, functional suppression assays and transcriptional profiling we analysed T_reg activation and characterised T-cells of the lamina propria as well as intraepithelial lymphocytes (IELs) regarding their activation and differentiation. Microbiota composition was examined in intestinal samples as well as in murine and human pancreatic necrosis by 16S rRNA gene sequencing.

RESULTS

The prophylactic T_reg-depletion enhanced the proinflammatory response in an experimental mouse model of AP but stabilised the intestinal immunological barrier function of Th17 cells and CD8⁺/γδTCR⁺ IELs. T_reg depleted animals developed less bacterial translocation to the pancreas. Duodenal overgrowth of the facultative pathogenic taxa Escherichia/Shigella which associates with severe disease and infected necrosis was diminished in T_reg depleted animals.

CONCLUSION

T_regs play a crucial role in the counterbalance against systemic inflammatory response syndrome. In AP, T_reg-activation disturbs the duodenal barrier function and permits translocation of commensal bacteria into pancreatic necrosis. Targeting T_regs in AP may help to ameliorate the disease course.

Role of neutrophil extracellular traps in inflammatory evolution in severe acute pancreatitis

ABSTRACT

Severe acute pancreatitis (SAP) is a life-threatening acute abdominal disease with two peaks of death: the first in the early stage, characterized by systemic inflammatory response-associated organ failure; and the second in the late stage, characterized by infectious complications. Neutrophils are the main immune cells participating in the whole process of SAP. In addition to the traditional recognition of neutrophils as the origination of chemokine and cytokine cascades or phagocytosis and degranulation of pathogens, neutrophil extracellular traps (NETs) also play an important roles in inflammatory reactions. We reviewed the role of NETs in the occurrence and development of SAP and its fatal complications, including multiple organs injury, infected pancreatic necrosis, and thrombosis. This review provides novel insights into the involvement of NETs throughout the entire process of SAP, showing that targeting NETs might be a promising strategy in SAP treatment. However, precision therapeutic options targeting NETs in different situations require further investigation.

Minimally invasive management of severe acute pancreatitis: Current status and future perspectives

In the past few years, the diagnosis and treatment of acute pancreatitis have moved towards a multidisciplinary, targeted, and minimally invasive approach. The optimal timing, route, and treatment strategy for intervention for local and systemic complications in patients with severe acute pancreatitis need to be re-evaluated. This review focuses on the development of minimally invasive management of severe acute pancreatitis in recent years and provides an outlook on future directions.

Impact of multiple drug-resistant Gram-negative bacterial bacteraemia on infected pancreatic necrosis patients

Introduction

Multiple drug-resistant Gram-negative bacterial (MDR-GNB) bacteraemia poses a serious threat to patients in hospital. Infected pancreatic necrosis (IPN) patients are a vulnerable population to infectious complications during hospitalization. This study aims to evaluate the impact of MDR Gram-negative bacteraemia on IPN patients.

Methods

A case-control study was performed with data collected from 1 January 2016 to 1 July 2022 in a Chinese tertiary teaching hospital. Clinical data of the IPN patients with MDR-GNB bacteraemia were analyzed and compared to those of a matched control group without MDR-GNB bacteraemia (case-control ratio of 1:2). Comparisons were performed between with/without MDR-GNB bacteraemia and different severities of acute pancreatitis (AP). Independent predictors of overall mortality were identified via univariate and multivariate binary logistic regression analyses.

Results

MDR-GNB bacteraemia was related to a higher mortality rate (62.5% vs. 8.3%, p < 0.001). Severe AP combined with MDR-GNB bacteraemia further increased mortality up to 81.3% (p = 0.025). MDR-GNB bacteraemia (odds ratio (OR) = 8.976, 95% confidence interval (CI) = 1.805 -44.620, p = 0.007) and severe AP (OR = 9.414, 95% CI = 1.742 -50.873, p = 0.009) were independent predictors of overall mortality. MDR- Klebsiella pneumoniae was the most common causative pathogen.

Conclusion

A higher mortality rate in IPN patients was related to MDR-GNB bacteraemia and further increased in severe AP patients combined with MDR-GNB bacteraemia.

Progress in research of acute pancreatitis in pregnancy

Acute pancreatitis in pregnancy (APIP) is a rare and severe complication of pregnancy, which is characterized by rapid onset, rapid progression, many complications, and high mortality. According to previous studies, the incidence of APIP is about 1/10000-1/1000 and increases with gestational age. Due to the differences in genetic background and dietary habits between Asian and European populations, the incidence of APIP in China is as high as 1.14‰-2.27‰, significantly higher than that in Western countries. The lack of specific clinical symptoms of APIP often leads to misdiagnosis or missed diagnosis, which greatly increases the difficulty of diagnosis and treatment. Despite the deepening of the research on APIP, its pathogenesis is still unclear. This paper will give a systematical review of APIP.

Risk Factors for Mortality Among Critical Acute Pancreatitis Patients with Carbapenem-Resistant Organism Infections and Drug Resistance of Causative Pathogens

Introduction

Carbapenem-resistant organisms (CRO) have emerged as a major global public health threat, but their role in critical acute pancreatitis (CAP) is still not defined. Our study aims to investigate risk factors associated with mortality and drug resistance among CAP patients with CRO infection.

Methods

The clinical characteristics of CAP patients with CRO infection and drug resistance of causative pathogens from January 1, 2016, to October 1, 2021, were reviewed retrospectively. Independent risk factors for mortality were determined via univariate and multivariate analyses.

Result

Eighty-two CAP patients suffered from CRO infection, with mortality of 60.0%. The independent risk factors for mortality were procalcitonin > 5 ng/L (hazard ratio = 2.300, 95% confidence interval = 1.180–4.484, P = 0.014) and lactic acid > 2 mmol/L (hazard ratio = 2.101, 95% confidence interval = 1.151–3.836, P = 0.016). The pancreas was the main site of infection, followed by lung, bloodstream and urinary tract. Klebsiella pneumoniae and Acinetobacter baumannii were the main pathogenic bacteria of CRO strains with extensive antibiotic resistance (> 60%) to 6 of 8 common antibiotics, except sulfamethoxazole (56.3%) and tigecycline (33.2%).

Conclusion

CRO infection has become a serious threat for CAP patients, with high rates of mortality. Procalcitonin and lactic acid represent two independent risk factors for mortality in CAP patients with CRO infection. Klebsiella pneumoniae and Acinetobacter baumannii are the primary categories of CRO pathogens. Greater efforts are needed for early prevention and prompt treatment of CRO infections in CAP patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00624-w.

Characteristics of and risk factors for biliary pathogen infection in patients with acute pancreatitis

Background

Infection in patients with acute pancreatitis, especially severe acute pancreatitis patients, is a common and important phenomenon, and the distributions and drug resistance profiles of bacteria causing biliary infection and related risk factors are dynamic. We conducted this study to explore the characteristics of and risk factors for bacterial infection in the biliary tract to understand antimicrobial susceptibility, promote the rational use of antibiotics, control multidrug-resistant bacterial infections and provide guidance for the treatment of acute pancreatitis caused by drug-resistant bacteria.

Methods

The distribution of 132 strains of biliary pathogenic bacteria in patients with acute pancreatitis from January 2016 to December 2020 were analyzed. We assessed drug resistance in the dominant Gram-negative bacteria and studied the drug resistance profiles of multidrug-resistant bacteria by classifying Enterobacteriaceae and nonfermentative bacteria. We then retrospectively analyzed the clinical data and risk factors associated with 72 strains of Gram-negative bacilli, which were divided into multidrug-resistant bacteria (50 cases) and non-multidrug-resistant bacteria (22 cases).

Results

The main bacteria were Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli had a 66.67% detection rate. Acinetobacter baumannii had more than 50.00% drug resistance to carbapenems, ESBL-producing Klebsiella pneumoniae had 100.00% drug resistance, and Pseudomonas aeruginosa had 66.67% resistance to carbapenems. Multivariate logistic regression analysis suggested that the administration of third- or fourth-generation cephalosporins was an independent risk factor for Gram-negative multidrug-resistant biliary bacterial infection in acute pancreatitis patients.

Conclusion

Drug resistance among biliary pathogens in acute pancreatitis patients remains high; therefore, rational antimicrobial drug use and control measures should be carried out considering associated risk factors to improve diagnosis and treatment quality in acute pancreatitis patients.

Predictors of Mortality and Drug Resistance Among Carbapenem-Resistant Enterobacteriaceae-Infected Pancreatic Necrosis Patients

Introduction

Carbapenem-resistant Enterobacteriaceae (CRE) has emerged as a global threat to hospitalization patients. Infected pancreatic necrosis (IPN) leads to high risks of CRE infections with increasing mortality. Our study aims to determine the predictors related to 90-day overall mortality of CRE IPN.

Methods

We retrospectively reviewed the drug resistance rates and clinical characteristics of CRE IPN patients from January 1, 2016, to January 1, 2021. Independent predictors of mortality were identified via univariate and multivariate analyses.

Results

During the 5-year period, 75 IPN patients suffered from 135 episodes of CRE infections with mortality up to 50.7%. CRE strains were highly resistant (> 50%) to nine of ten common antibiotics, except tigecycline (18%). The most common pathogen was carbapenem-resistant Klebsiella pneumoniae (84 of 135). Lung was the main site of extrapancreatic infections, followed by bloodstream and biliary tract. The independent predictors of mortality were Sequential Organ Failure Assessment (SOFA) score > 2 (hazard ratio 3.746, 95% confidence interval 1.209–11.609, P = 0.022) and procalcitonin > 6 ng/l (hazard ratio 2.428, 95% confidence interval 1.204–4.895, P = 0.013).

Conclusion

CRE is widespread as a global challenge with a high mortality rate among IPN patients due to limited therapeutic options. Carbapenem-resistant K. pneumoniae is the leading category of CRE which requires more attention in clinical practice. High SOFA score and procalcitonin level represent two independent predictors of mortality in CRE IPN patients. Greater efforts are needed toward timely therapeutic intervention for CRE IPN.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00489-5.

Endoscopic Management of Pancreatic Fluid Collections

Pancreatic fluid collections (PFCs) are a common sequela of pancreatitis. Most PFCs can be managed conservatively, but symptomatic PFCs require either surgical, percutaneous, or endoscopic intervention. Recent advances in the therapeutics of PFCs, including the step-up approach, endoscopic ultrasound-guided transmural drainage with lumen apposing metal stents, and direct endoscopic necrosectomy, have ushered endoscopy to the forefront of PFCs management and have allowed for improved patient outcomes and decreased morbidity. In this review, we explore the progress and future of endoscopic management of PFCs.

Compositional and drug-resistance profiling of pathogens in patients with severe acute pancreatitis: a retrospective study

Background

Infection is one of the important causes of death in patients with severe acute pancreatitis (SAP), but the bacterial spectrum and antibiotic resistance are constantly changing. Making good use of antibiotics and controlling multi-drug-resistant (MDR) bacterial infections are of vital importance in improving the cure rate of SAP. We conducted a retrospective study in the hope of providing references for antibiotic selection and control of drug-resistant bacteria.

Methods

Retrospective analysis was performed on the data of patients hospitalized in our hospital due to acute pancreatitis (AP) in the past 5 years. General data were classified and statistically analyzed. Subsequently, the bacterial spectrum characteristics and the data related to drug-resistant bacterial infection of 569 AP patients were analyzed. Finally, unconditional logistic regression analysis was conducted to analyze the risk factors of MDR infection.

Results

A total of 398 patients were enrolled in this study and the hospitalization data and associated results were analyzed. A total of 461 strains of pathogenic bacteria were detected, including 223 (48.4%) gram-negative bacterial strains, 190 (41.2%) gram-positive bacterial strains and 48 (10.4%) fungal strains. The detection rates of resistance in gram-negative and gram-positive bacterial strains were 48.0% (107/223) and 25.3% (48/190), respectively. There were significant differences between the MDR group and the non-MDR group for the factors of precautionary antibiotic use, kinds of antibiotics used, receipt of carbapenem, tracheal intubation, hemofiltration and number of hospitalization days in the intensive care unit. Unconditional logistic regression revealed 2 risk factors for MDR bacterial infection.

Conclusions

Our results illustrate that gram-negative bacteria were the most common pathogens in SAP infection, and the proportion of gram-positive bacteria increased notably. The rate of antibiotic resistance was higher than previously reported. Unconditional logistic regression analysis showed that using more types of antibiotics and the number of hospitalization days in the ICU were the risk factors associated with MDR bacterial infection.

Extrapancreatic infections are common in acute pancreatitis and they are related to organ failure: a population-based study

BACKGROUND

Although the impact of pancreatic infections in acute pancreatitis has been studied extensively, there are no population-based data on extrapancreatic infections and their potential relation to organ failure. We aimed to study the occurrence of pancreatic and extrapancreatic bacterial infections in acute pancreatitis and their relation to patient outcome.

PATIENTS AND METHODS

All patients with first-time acute pancreatitis from 2003 to 2012 in a defined area in Sweden were retrospectively evaluated. Data on acute pancreatitis severity, organ failure, infections, and in-hospital mortality were collected.

RESULTS

Overall, 304 bacterial infections occurred in 248/1457 patients (17%). Fifteen percent had extrapancreatic and 2% had pancreatic infections. The lungs (35%), the urinary tract (24%), and the bile ducts (18%) were the most common sites of extrapancreatic infections. Organ failure, severe acute pancreatitis, and in-hospital mortality were more common in patients with vs those without (pancreatic/extrapancreatic) infections (P < 0.05). Organ failure and severe acute pancreatitis occurred more frequently in pancreatic vs extrapancreatic infections (70% vs 34%, P < 0.001 and 67% vs 28%, P < 0.001), but in-hospital mortality did not differ between the two groups (7.4% vs 6.8%, P = 1.0). Both pancreatic and extrapancreatic infections were independent predictors of organ failure (P < 0.05). Out of culture-positive infections, 18% were due to antibiotic-resistant bacteria, without any significant difference between extrapancreatic vs pancreatic infections (P > 0.05). About two out of five infections were of nosocomial origin.

CONCLUSION

Extrapancreatic infections occurred in 15% and pancreatic infections in 2% of patients with first-time acute pancreatitis. Both pancreatic and extrapancreatic infections were independent predictors of organ failure, leading to increased mortality.

Use of antibiotics in acute pancreatitis: ten major concerns

Acute pancreatitis is one of the most common gastrointestinal causes for hospitalization. In 15-20% it evolves into severe necrotizing pancreatitis. Recent studies have shown no association between the initiation of antibiotic therapy in acute pancreatitis and severe outcomes such as organ failure, infection of pancreatic necrosis, extrapancreatic infections or mortality. Specific subgroups with predicted severe acute pancreatitis or both extensive sterile necrosis and persistent organ failure may benefit from prophylactic antibiotics. Local infection develops in 30% of patients with pancreatic necrosis and results in morbidity and mortality. Contrast enhanced computed tomography should be performed in all patients with acute pancreatitis who develop sepsis, organ failure or fail to improve. C-reactive protein is an independent predictor of severe acute pancreatitis. Procalcitonin is the most sensitive laboratory test for detection of pancreatic infection. Antibiotics do however play a large role in patients with suspected or confirmed infected pancreatic necrosis and extrapancreatic infections. In clinical practice most clinicians prescribe antibiotics in the first 3 days of acute pancreatitis which in turns lead to excessive, unjustified use of antibiotics. Deep knowledge of the recent guidelines combined with an individualized management based on right clinical judgment is a rationale approach of patients with acute pancreatitis.

ATF6 aggravates acinar cell apoptosis and injury by regulating p53/AIFM2 transcription in Severe Acute Pancreatitis

Background: There is no curative therapy for severe acute pancreatitis (SAP) due to poor understanding of its molecular mechanisms. Endoplasmic reticulum (ER) stress is involved in SAP and increased expression of ATF6 has been detected in SAP patients. Here, we aimed to investigate the role of ATF6 in a preclinical SAP mouse model and characterize its regulatory mechanism. Methods: Pancreatic tissues of healthy and SAP patients were collected during surgery. Humanized PRSS1 transgenic mice were treated with caerulein to mimic the SAP development, which was crossed to an ATF6 knockout mouse line, and pancreatic tissues from the resulting pups were screened by proteomics. Adenovirus-mediated delivery to the pancreas of SAP mice was used for shRNA-based knockdown or overexpression. The potential functions and mechanisms of ATF6 were clarified by immunofluorescence, immunoelectron microscopy, Western blotting, qRT-PCR, ChIP-qPCR and luciferase reporter assay. Results: Increased expression of ATF6 was associated with elevated apoptosis, ER and mitochondrial disorder in pancreatic tissues from SAP patients and PRSS1 mice. Knockout of ATF6 in SAP mice attenuated acinar injury, apoptosis and ER disorder. AIFM2, known as a p53 target gene, was identified as a downstream regulatory partner of ATF6, whose expression was increased in SAP. Functionally, AIFM2 could reestablish the pathological disorder in SAP tissues in the absence of ATF6. p53 expression was also increased in SAP mice, which was downregulated by ATF6 knockout. p53 knockout significantly suppressed acinar apoptosis and injury in SAP model. Mechanistically, ATF6 promoted AIFM2 transcription by binding to p53 and AIFM2 promoters. Conclusion: These results reveal that ATF6/p53/AIFM2 pathway plays a critical role in acinar apoptosis during SAP progression, highlighting novel therapeutic target molecules for SAP.