Fire in the belly: A scoping review of the immunopathological mechanisms of acute pancreatitis

Acute pancreatitis risk in the diagnosis and management of inflammatory bowel disease: A critical focus

Objective

We explored the causal relationship between pancreatitis and various autoimmune diseases using bidirectional Mendelian randomization (MR).

Methods

We collected genome-wide association study summary data for four pancreatitis types and five autoimmune diseases to conduct our bidirectional MR analysis. The primary analysis was performed using the inverse variance weighted (IVW) method, complemented by MR Egger, weighted median, and weighted mode methods. Sensitivity analyses included Cochran's Q test for heterogeneity, MR-Egger regression for pleiotropy, and MR-PRESSO and leave-one-out analyses for outliers.

Results

The result of IVW revealed a significant association between genetically predicted inflammatory bowel disease (IBD) and an increased risk of acute pancreatitis (AP) (odds ratio [OR] = 1.07, 95% confidence interval [CI] = 1.03-1.12, P = 0.0015). Subsequent analyses further confirmed this association in IBD subtypes, with genetically predicted ulcerative colitis (UC) and Crohn's disease (CD) also showing increased risks of AP (UC: OR = 1.07, 95% CI = 1.02-1.13, P = 0.01; CD: OR = 1.05, 95% CI = 1-1.09, P = 0.03), affirming IBD as a risk factor for pancreatitis. Reverse analysis ruled out reverse causality and did not find a causal relationship between other immune diseases and pancreatitis.

Conclusion

These findings suggest that pancreatitis in IBD patients may arise from the disease itself, necessitating increased vigilance for AP during diagnosis and treatment.

Hypertriglyceridemia-Induced and Alcohol-Induced Acute Pancreatitis-A Severity Comparative Study

Background: Alcohol use and hypertriglyceridemia are the second and third common causes of acute pancreatitis after choledocholithiasis. Still, few studies directly compare the severity and outcomes of these two groups, which share pathophysiology pathways. Methods: In our study, we compared the biologic profile, severity according to the Atlanta classification and Balthazar index, intensive care unit admissions, and mortality between patients with hypertriglyceridemia-induced pancreatitis (HTGP) and alcohol-induced acute pancreatitis (AAP). A total of 78 patients were included in this study, 37.17% of which had HTGP, and 62.82% had AAP. Results: HTGP was more severe in terms of the Atlanta revised classification severity assessment (82.76% vs. 46%, p = 0.014), led to more extended hospitalizations (p = 0.024), and resulted in similar serum CRP levels among patients, with a significant difference regarding median serum fibrinogen values (739 vs. 563 mg/dL, p = 0.030) and necrotizing forms (24.13% vs. 10.20%). Hyponatremia was more significant in HTGP patients compared with AAP patients (130 vs. 137 mmol/L, p < 0.000). No differences were found in other inflammation indexes such as NLR (neutrophil count/lymphocyte count), PLR (platelet count/lymphocyte count), MLR (monocyte/lymphocyte count), SII (systemic immune-inflammation index), or SIRI (systemic inflammation response index). Conclusions: The pattern of acute pancreatitis is related to its etiology and may have different grades of severity. In our study, we found that hypertriglyceridemia-induced pancreatitis required twice as many admissions to the intensive care unit and was associated with lower serum sodium levels, and almost twice as many patients with HTGP had moderate or severe forms of acute pancreatitis compared to alcohol-induced pancreatitis cases.

B Lymphocyte-A Prognostic Indicator in Post-Acute Pancreatitis Diabetes Mellitus

OBJECTIVE

To determine the value of lymphocyte subsets and granulocyte/monocyte surface markers in predicting the risk of post-acute pancreatitis diabetes (PPDM-A).

METHODS

This study included 308 in patients with acute pancreatitis (AP). The markers of granulocytes and monocytes and lymphocyte subsets were detected by flow cytometry, and the fluorescence intensity, absolute count and percentage were obtained. Based on the occurrence of diabetes after AP, patients were divided into two groups: PPDM-A and PPNG-A (post-acute pancreatitis with normal glucose). Correlations between granulocyte and monocyte surface markers and lymphocyte subsets were analyzed. Binary logistic regression was used to analyze the potential influencing factors of PPDM-A.

METHODS

Compared with patients with PPNG-A, patients with PPDM-A tend to be younger (p < 0.001) and have a higher proportion of fatty liver, recurrent pancreatitis, and hyperlipidemic pancreatitis. The results of linear regression showed that B% was negatively correlated with MFI of HLA-DR on monocytes (R2 = 0.145, p < 0.001), B% was positively correlated with CD10-NEUT% (R2 = 0.291, p < 0.001), and MFI of HLA-DR on monocytes was negatively correlated with CD10-NEUT% (R2 = 0.457, p < 0.001). Multivariate logistic regression analysis revealed that age, serous effusion, fatty liver, recurrent pancreatitis, and B% were independent risk factors for the occurrence of PPDM-A.

CONCLUSION

Our study has first confirmed the correlation between PPDM-A and lymphocyte subsets and CD10-NEUT%. Furthermore we indicated that age, fatty liver, serous effusion, recurrent AP, and B% were independent risk factors for PPDM-A. The mechanism of granulocyte and monocyte surface markers and B lymphocytes on PPDM-A is worthy of study. This would help clarify the pathogenesis of PPDM-A at the cellular level and potentially provide new strategies for immunotherapy and even disease prevention.

Discovery of glycosidated glycyrrhetinic acid derivatives: Natural product-based soluble epoxide hydrolase inhibitors

There are few reports on soluble epoxide hydrolase (sEH) structure-activity relationship studies using natural product-based scaffolds. In this study, we discovered that C-30 urea derivatives of glycyrrhetinic acid such as 33, rather than C-20/C-3 urea derivatives, possess in vitro sEH inhibitory capabilities. Furthermore, we explored the impact of stereoconfigurations at C-3 and C-18 positions, and glycosidic bonds at the 3-OH on the compound's activity. Consequently, a glycoside of 33, specifically 49Cα containing alpha-oriented mannose, exhibited promising in vivo efficacy in alleviating carrageenan-induced paw edema and acetic acid-induced writhing. Meanwhile, 49Cα demonstrated potential in mitigating acute pancreatitis by modulating the ratios of anti-inflammatory epoxyeicosatrienoic acids (EETs) to pro-inflammatory dihydroxyeicosatrienoic acids (DHETs). The co-crystal structure of sEH in complex with 49Cα revealed that the N-tetrahydropyranylmethylene urea hydrogen bonded with the residues within the sEH tunnel, contrasting with the mannose component that extended beyond the tunnel's confines. Our findings highlight 49Cα (coded LQ-38) as a promising candidate for anti-inflammatory and analgesic effects, and pave the way for the future rational design of triterpenoid-based sEH inhibitors.

Feeding Intolerance-A Key Factor in the Management of Acute Pancreatitis: A Review

Acute pancreatitis (AP) is one of the most common diseases of the gastrointestinal tract, which in 20% of cases can turn into a severe form, with mortality reaching up to 30%. One of the cornerstones of AP treatment is early nutritional treatment. Feeding intolerance (FI) occurs in up to 25% of patients with AP and is associated with a more severe disease course and poorer clinical outcome. Feeding intolerance can have a multifaceted clinical presentation. The early identification of FI risk factors and appropriately conducted nutritional treatment are critical to the course of the disease. In this review, we summarize the current knowledge of feeding intolerance in AP, its pathomechanisms and risk factors, and its impact on disease progression. We also present suggestions for the management of feeding intolerance.

Altered immune cell in human severe acute pancreatitis revealed by single-cell RNA sequencing

Background

Severe acute pancreatitis (SAP) is characterized by inflammation, with inflammatory immune cells playing a pivotal role in disease progression. This study aims to understand variations in specific immune cell subtypes in SAP, uncover their mechanisms of action, and identify potential biological markers for predicting Acute Pancreatitis (AP) severity.

Methods

We collected peripheral blood from 7 untreated SAP patients and employed single-cell RNA sequencing for the first time to construct a transcriptome atlas of peripheral blood mononuclear cells (PBMCs) in SAP. Integrating SAP transcriptomic data with 6 healthy controls from the GEO database facilitated the analysis of immune cell roles in SAP. We obtained comprehensive transcriptomic datasets from AP samples in the GEO database and identified potential biomarkers associated with AP severity using the "Scissor" tool in single-cell transcriptomic data.

Results

This study presents the inaugural construction of a peripheral blood single-cell atlas for SAP patients, identifying 20 cell subtypes. Notably, there was a significant decrease in effector T cell subsets and a noteworthy increase in monocytes compared to healthy controls. Moreover, we identified a novel monocyte subpopulation expressing high levels of PPBP and PF4 which was significantly elevated in SAP. The proportion of monocyte subpopulations with high CCL3 expression was also markedly increased compared to healthy controls, as verified by flow cytometry. Additionally, cell communication analysis revealed insights into immune and inflammation-related signaling pathways in SAP patient monocytes. Finally, our findings suggest that the subpopulation with high CCL3 expression, along with upregulated pro-inflammatory genes such as S100A12, IL1B, and CCL3, holds promise as biomarkers for predicting AP severity.

Conclusion

This study reveals monocytes' crucial role in SAP initiation and progression, characterized by distinct pro-inflammatory features intricately linked to AP severity. A monocyte subpopulation with elevated PPBP and CCL3 levels emerges as a potential biomarker and therapeutic target.

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.

Enhancing acute inflammatory and sepsis treatment: superiority of membrane receptor blockade

Conditions such as acute pancreatitis, ulcerative colitis, delayed graft function and infections caused by a variety of microorganisms, including gram-positive and gram-negative organisms, increase the risk of sepsis and therefore mortality. Immune dysfunction is a characterization of sepsis, so timely and effective treatment strategies are needed. The conventional approaches, such as antibiotic-based treatments, face challenges such as antibiotic resistance, and cytokine-based treatments have shown limited efficacy. To address these limitations, a novel approach focusing on membrane receptors, the initiators of the inflammatory cascade, is proposed. Membrane receptors such as Toll-like receptors, interleukin-1 receptor, endothelial protein C receptor, μ-opioid receptor, triggering receptor expressed on myeloid cells 1, and G-protein coupled receptors play pivotal roles in the inflammatory response, offering opportunities for rapid regulation. Various membrane receptor blockade strategies have demonstrated efficacy in both preclinical and clinical studies. These membrane receptor blockades act as early stage inflammation modulators, providing faster responses compared to conventional therapies. Importantly, these blockers exhibit immunomodulatory capabilities without inducing complete immunosuppression. Finally, this review underscores the critical need for early intervention in acute inflammatory and infectious diseases, particularly those posing a risk of progressing to sepsis. And, exploring membrane receptor blockade as an adjunctive treatment for acute inflammatory and infectious diseases presents a promising avenue. These novel approaches, when combined with antibiotics, have the potential to enhance patient outcomes, particularly in conditions prone to sepsis, while minimizing risks associated with antibiotic resistance and immune suppression.

The Pathogenesis of Pancreatitis and the Role of Autophagy

The pathogenesis of acute and chronic pancreatitis has recently evolved as new findings demonstrate a complex mechanism operating through various pathways. In this review, the current evidence indicating that several mechanisms act in concert to induce and perpetuate pancreatitis were presented. As autophagy is now considered a fundamental mechanism in the pathophysiology of both acute and chronic pancreatitis, the fundamentals of the autophagy pathway were discussed to allow for a better understanding of the pathophysiological mechanisms of pancreatitis. The various aspects of pathogenesis, including trypsinogen activation, ER stress and mitochondrial dysfunction, the implications of inflammation, and macrophage involvement in innate immunity, as well as the significance of pancreatic stellate cells in the development of fibrosis, were also analyzed. Recent findings on exosomes and the miRNA regulatory role were also presented. Finally, the role of autophagy in the protection and aggravation of pancreatitis and possible therapeutic implications were reviewed.

Cytokine Dynamics in Acute Pancreatitis: The Quest for Biomarkers from Acute Disease to Disease Resolution

Background: Acute pancreatitis (AP) is an inflammatory disease of the pancreas with incompletely known pathogenic mechanisms. This study aimed to explore the temporal changes in serum cytokines in patients with AP and to assess the association of these changes with disease severity. Methods: Fifty patients hospitalized with AP were enrolled, and their serum cytokine levels were analyzed at four different time points. A healthy control (HC) group of 30 outpatients was included. Results: AP patients showed increased levels of interleukin (IL)-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-alpha, and monocyte chemoattractant protein (MCP)-1 at admission when compared with HC. IL-6, VEGF, and EGF remained elevated 1 month after hospitalization and 6 months after discharge. Conclusions the Bedside Index of Severity in Acute Pancreatitis (BISAP) and severity classification of the revised Atlanta classification system, IL-6 and VEGF, determined 48 h after hospitalization, were the two cytokines consistently elevated in the most severe patients. Increased levels of IL-4, IL-6, IL-10, and TNF-alpha at admission and MCP-1 48 h after admission are also related to the length of hospital stay. Conclusions: Our study highlights the role cytokines play in the pathogenesis of AP and can be useful in the development of future drug trials for AP.

The relationship between inflammatory cytokines and in-hospital complications of acute pancreatitis

OBJECTIVE

Acute necrotic collection (ANC), acute peripancreatic fluid collection (APFC), pleural effusion, and ascites are common early complications of acute pancreatitis. This study aimed to investigate the relationship between 12 serum cytokines and the early complications and severity of acute pancreatitis (AP).

METHODS

We retrospectively analyzed the clinical data of 307 patients with AP, and divided them into severe group and mild-to-moderate group according to the revised Atlanta classification. Propensity score matching was used to control for confounding factors. Binary logistic regression analysis was used to explore the relationship between cytokine levels and early complications of AP.

RESULTS

Serum levels of interleukin (IL)-1β, IL-5, IL-6, IL-8, IL-10, IL-17, and tumor necrosis factor-α were significantly higher in the severe acute pancreatitis (SAP) group than in the non-SAP group (p < .05). After adjusting for confounding factors, the upper quartiles of IL-6, IL-8, and IL-10 were associated with an increased risk of ANC compared with those in the lowest quartile (IL-6: quartile 3, odds ratio [OR] = 3.99, 95% confidence interval [CI] = 1.95-8.16; IL-8: quartile 4, OR = 2.47, 95% CI = 1.27-4.84; IL-10: quartile 2, OR = 2.22, 95% CI = 1.09-4.56). APFC was associated with high serum levels of IL-6 (quartile 3, OR = 1.32, 95% CI = 1.02-1.72), pleural effusions were associated with high serum levels of IL-1β, IL-6, IL-8, and IL-10 (IL-1β: quartile 4, OR = 2.36, 95% CI = 1.21-4.58; IL-6: quartile 3, OR = 4.67, 95% CI = 2.27-9.61; IL-8: quartile 3, OR = 2.95, 95% CI = 1.51-5.79; IL-10: quartile 4, OR = 3.20, 95% CI = 1.61-6.36), and high serum levels of IL-6 and IL-10 were associated with an increased risk of ascites (IL-6: quartile 3, OR = 3.01, 95% CI = 1.42-6.37; IL-10: quartile 3, OR = 2.57, 95% CI = 1.23-5.37).

CONCLUSION

Serum cytokine levels, including IL-1β, IL-6, IL-8, and IL-10 may be associated with the occurrence of early complications of AP. In daily clinical practice, IL-6 may be the most worthwhile cytokine to be detected.

Pro-inflammatory cytokines stimulate CFTR-dependent anion secretion in pancreatic ductal epithelium

BACKGROUND

Loss of CFTR-dependent anion and fluid secretion in the ducts of the exocrine pancreas is thought to contribute to the development of pancreatitis, but little is known about the impact of inflammation on ductal CFTR function. Here we used adult stem cell-derived cell cultures (organoids) obtained from porcine pancreas to evaluate the effects of pro-inflammatory cytokines on CFTR function.

METHODS

Organoids were cultured from porcine pancreas and used to prepare ductal epithelial monolayers. Monolayers were characterized by immunocytochemistry. Epithelial bicarbonate and chloride secretion, and the effect of IL-1β, IL-6, IFN-γ, and TNF-α on CFTR function was assessed by electrophysiology.

RESULTS

Immunolocalization of ductal markers, including CFTR, keratin 7, and zonula occludens 1, demonstrated that organoid-derived cells formed a highly polarized epithelium. Stimulation by secretin or VIP triggered CFTR-dependent anion secretion across epithelial monolayers, whereas purinergic receptor stimulation by UTP, elicited CFTR-independent anion secretion. Most of the anion secretory response was attributable to bicarbonate transport. The combination of IL-1β, IL-6, IFN-γ, and TNF-α markedly enhanced CFTR expression and anion secretion across ductal epithelial monolayers, whereas these cytokines had little effect when tested separately. Although TNF-α triggered apoptotic signaling, epithelial barrier function was not significantly affected by cytokine exposure.

CONCLUSIONS

Pro-inflammatory cytokines enhance CFTR-dependent anion secretion across pancreatic ductal epithelium. We propose that up-regulation of CFTR in the early stages of the inflammatory response, may serve to promote the removal of pathogenic stimuli from the ductal tree, and limit tissue injury.

B Cells and Double-Negative B Cells (CD27-IgD-) Are Related to Acute Pancreatitis Severity

Acute pancreatitis (AP) is an increasingly frequent disease in which inflammation plays a crucial role. Fifty patients hospitalized with AP were included and peripheral blood samples were analyzed for B and T cell subpopulations at the time of hospitalization and 48 h after diagnosis. The Bedside Index of Severity in Acute Pancreatitis (BISAP) and length of hospital stay were also recorded. A healthy control (HC) group of 15 outpatients was included. AP patients showed higher neutrophil/lymphocyte (N/L) ratios and higher percentages of B cells than the HC group. The total B cell percentages were higher in patients with moderate/severe AP than in patients with mild AP. The percentages of B cells as well as the percentages of the CD27-IgD- B cell subset decreased from admission to 48 h after admission. The patients with higher BISAP scores showed lower percentages of peripheral lymphocytes but higher percentages of CD27-IgD- B cells. Higher BISAP scores, N/L ratios, and peripheral blood B cell levels emerged as predictors of hospital stay length in AP patients. Our findings underscore the importance of early markers for disease severity. Additionally, the N/L ratio along with the BISAP score and circulating B cell levels form a robust predictive model for hospital stay duration of AP patients.

Inhibition of Gasdermin D blocks the formation of NETs and protects acute pancreatitis in mice

The persistent activation of neutrophils and the excessive neutrophil extracellular traps (NETs) formation are the main determinants of pancreatic tissue injury and systemic inflammatory response in acute pancreatitis (AP). Thus, inhibiting the release of NETs can effectively prevent the aggravation of AP. Here, our study showed that the pore-forming protein gasdermin D (GSDMD) was activity in neutrophils of AP mice and patients and played the vital role in NETs formation. Through the application of GSDMD inhibitor or the construction of neutrophil GSDMD specific knockout mice, it was found in vivo and in vitro that inhibition of GSDMD could block the NETs formation, reduce pancreatic injury, systemic inflammatory reaction and organ failure in AP mice. To sum up, our findings confirmed that neutrophil GSDMD was the therapeutic target for improving the occurrence and development of AP.