Distinct immune characteristics distinguish hereditary and idiopathic chronic pancreatitis

Systemic Neutrophil Gelatinase-Associated Lipocalin Alterations in Chronic Pancreatitis: A Multicenter, Cross-Sectional Study

INTRODUCTION

Chronic pancreatitis (CP) is a progressive fibroinflammatory disorder lacking therapies and biomarkers. Neutrophil gelatinase-associated lipocalin (NGAL) is a proinflammatory cytokine elevated during inflammation that binds fatty acids (FAs) such as linoleic acid. We hypothesized that systemic NGAL could serve as a biomarker for CP and, with FAs, provide insights into inflammatory and metabolic alterations.

METHODS

NGAL was measured by immunoassay, and FA composition was measured by gas chromatography in plasma (n = 171) from a multicenter study, including controls (n = 50), acute and recurrent acute pancreatitis (AP/RAP) (n = 71), and CP (n = 50). Peripheral blood mononuclear cells (PBMCs) from controls (n = 16), AP/RAP (n = 17), and CP (n = 15) were measured by cytometry by time-of-flight.

RESULTS

Plasma NGAL was elevated in subjects with CP compared with controls (area under the curve [AUC] = 0.777) or AP/RAP (AUC = 0.754) in univariate and multivariate analyses with sex, age, body mass index, and smoking (control AUC = 0.874; AP/RAP AUC = 0.819). NGAL was elevated in CP and diabetes compared with CP without diabetes ( P < 0.001). NGAL + PBMC populations distinguished CP from controls (AUC = 0.950) or AP/RAP (AUC = 0.941). Linoleic acid was lower, whereas dihomo-γ-linolenic and adrenic acids were elevated in CP ( P < 0.05). Linoleic acid was elevated in CP with diabetes compared with CP subjects without diabetes ( P = 0.0471).

DISCUSSION

Elevated plasma NGAL and differences in NGAL + PBMCs indicate an immune response shift that may serve as biomarkers of CP. The potential interaction of FAs and NGAL levels provide insights into the metabolic pathophysiology and improve diagnostic classification of CP.

Genetic insights into across pancreatitis types: the causal influence of immunoglobulin G N-glycosylation variants on disease risk

Background

While a few case-control studies indicated a possible correlation of IgG N-glycosylation patterns with pancreatitis, their restricted sample sizes and methodologies prevented conclusive insights into causality or distinguishing traits across pancreatitis types.

Method

We conducted a two-sample Mendelian Randomization (MR) analysis to investigate the causal relationship between 77 IgG N-glycosylation traits and various types of pancreatitis, including acute pancreatitis (AP), chronic pancreatitis (CP), alcohol acute pancreatitis (AAP), and alcohol chronic pancreatitis (ACP). This analysis utilized summary-level data from genome-wide association studies (GWAS), employing methods such as IVW, MR-Egger, and weighted median. To ensure the robustness of our findings, several sensitivity analyses, including Cochran's Q statistic, leave-one-out, MR-Egger intercept, and MR-PRESSO global test were conducted.

Result

Our study uncovered the causal relationship between specific IgG N-glycosylation traits and various types of pancreatitis. Notably, an increase in genetically predicted IGP7 levels was associated with a decreased risk of developing AP. For CP, our data suggested a protective effect associated with higher levels of both IGP7 and IGP31, contrasting with increased levels of IGP27 and IGP65, which were linked to a heightened risk. Moreover, in the case of AAP, elevated IGP31 levels were causatively associated with a lower incidence, while higher IGP26 levels correlated with an increased risk for ACP.

Conclusion

This study establishes causal relationship between specific IgG N-glycosylation patterns and varying risks of different pancreatitis forms, underscoring their potential as predictive biomarkers. These findings necessitate further exploration into the underlying mechanisms, promising to inform more personalized diagnostic and therapeutic strategies in pancreatitis management.

Management of chronic pancreatitis

Chronic pancreatitis results from repeated episodes of pancreatic inflammation and associated fibrosis leading to the loss of functional exocrine and endocrine pancreatic function. The disease is manifested by abdominal pain, deterioration in quality of life, food maldigestion and malabsorption, diabetes, and an increased risk for pancreatic adenocarcinoma. This review summarizes the latest evidence on the diagnosis and management of chronic pancreatitis and its manifestations. In particular, this review discusses advances in understanding of the role of genetic disorders in the mechanisms of the disease and surgical options for patients refractory to medical therapy. Furthermore, clinical trials are under way to develop medical therapeutics.

Single-Cell Sequencing Data Analysis Unveiled HDAC1 as the Therapeutic Target for Chronic Pancreatitis

Chronic pancreatitis (CP) as a progressive inflammatory disorder, remains untreatable. The novel treatment strategy for CP is imperative. We attempted to explore the therapeutic biomarkers for CP. The single-cell sequencing data were retrieved from Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) in idiopathic CP were identified, followed by function and pathway annotation, and PPI network established. DEGs of interest were verified in human tissue samples. The function of candidate biomarker was determined in the murine model with CP. A total of 208 genes were specially differentially expressed in idiopathic patients. Functional enrichment analysis showed DEGs were mainly enriched in glycogen catabolic process, RNA splicing, and glucagon signaling pathway. A PPI network centered on HDAC1 was constructed. HDAC1 was overexpressed in CP patients. The murine model with CP was induced by repetitive cerulein treatment. Silencing sh-HDAC1 treatment reversed cerulein-induced inflammatory cells accumulation, high expression of TGF-β1, and collagen 1 in pancreas in vivo. HDAC1 might be served as potential biomarker for CP. The present study provided insights into the molecular mechanism of CP that may be useful in further investigations.

Immune response mechanisms in acute and chronic pancreatitis: strategies for therapeutic intervention

Acute pancreatitis (AP) is one of the most common inflammatory diseases of the gastrointestinal tract and a steady rising diagnosis for inpatient hospitalization. About one in four patients, who experience an episode of AP, will develop chronic pancreatitis (CP) over time. While the initiating causes of pancreatitis can be complex, they consistently elicit an immune response that significantly determines the severity and course of the disease. Overall, AP is associated with a significant mortality rate of 1-5%, which is caused by either an excessive pro-inflammation, or a strong compensatory inhibition of bacterial defense mechanisms which lead to a severe necrotizing form of pancreatitis. At the time-point of hospitalization the already initiated immune response is the only promising common therapeutic target to treat or prevent a severe disease course. However, the complexity of the immune response requires fine-balanced therapeutic intervention which in addition is limited by the fact that a significant proportion of patients is in danger of development or progress to recurrent and chronic disease. Based on the recent literature we survey the disease-relevant immune mechanisms and evaluate appropriate and promising therapeutic targets for the treatment of acute and chronic pancreatitis.

Reg family proteins contribute to inflammation and pancreatic stellate cells activation in chronic pancreatitis

Chronic pancreatitis (CP) is a disease characterized by the inflammation and destruction of pancreatic tissue, leading to the replacement of functional tissue with fibrotic tissue. The regenerating gene (Reg) family proteins have recently been implicated in the repair and regeneration of inflamed pancreatic tissue, though the exact mechanisms of their involvement in the pathogenesis of CP are not yet fully understood. To investigate the role of Reg family proteins in CP, we generated global knockout mice (Reg^-/-) for Reg1-3 (Reg1,2,3a,3b,3d,3g) genes using the CRISPR/Cas9 system. We then investigated the effect of Reg family protein deficiency in a genetic model of CP (X-SPINK1) mice by knocking out Reg1-3 genes. We examined pancreatic morphology, inflammatory cytokines expression, and activation of pancreatic stellate cells (PSCs) at different ages. Reg^-/- mice showed no abnormalities in general growth and pancreas development. Deficiency of Reg1-3 in CP mice led to a reduction in pancreatic parenchymal loss, decreased deposition of collagen, and reduced expression of proinflammatory cytokines. Additionally, Reg proteins were found to stimulate PSCs activation. Overall, our study suggests that Reg1-3 deficiency can lead to the remission of CP and Reg family proteins could be a potential therapeutic target for the treatment of CP.

Immune cells and immune cell-targeted therapy in chronic pancreatitis

In recent years, studies have attempted to understand the immune cells and mechanisms underlying the pathogenesis of chronic pancreatitis (CP) by constructing a model of CP. Based on these studies, the innate immune response is a key factor in disease pathogenesis and inflammation severity. Novel mechanisms of crosstalk between immune and non-immune pancreatic cells, such as pancreatic stellate cells (PSC), have also been explored. Immune cells, immune responses, and signaling pathways in CP are important factors in the development and progression of pancreatitis. Based on these mechanisms, targeted therapy may provide a feasible scheme to stop or reverse the progression of the disease in the future and provide a new direction for the treatment of CP. This review summarizes the recent advances in research on immune mechanisms in CP and the new advances in treatment based on these mechanisms.

Single-cell sequencing unveils distinct immune microenvironments with CCR6-CCL20 crosstalk in human chronic pancreatitis

OBJECTIVE

Chronic pancreatitis (CP) is a potentially fatal disease of the exocrine pancreas, with no specific or effective approved therapies. Due to difficulty in accessing pancreas tissues, little is known about local immune responses or pathogenesis in human CP. We sought to characterise pancreatic immune responses using tissues derived from patients with different aetiologies of CP and non-CP organ donors in order to identify key signalling molecules associated with human CP.

DESIGN

We performed single-cell level cellular indexing of transcriptomes and epitopes by sequencing and T-cell receptor (TCR) sequencing of pancreatic immune cells isolated from organ donors, hereditary and idiopathic patients with CP who underwent total pancreatectomy. We validated gene expression data by performing flow cytometry and functional assays in a second patient with CP cohort.

RESULTS

Deep single-cell sequencing revealed distinct immune characteristics and significantly enriched CCR6⁺ CD4⁺ T cells in hereditary compared with idiopathic CP. In hereditary CP, a reduction in T-cell clonality was observed due to the increased CD4⁺ T (Th) cells that replaced tissue-resident CD8⁺ T cells. Shared TCR clonotype analysis among T-cell lineages also unveiled unique interactions between CCR6⁺ Th and Th1 subsets, and TCR clustering analysis showed unique common antigen binding motifs in hereditary CP. In addition, we observed a significant upregulation of the CCR6 ligand (CCL20) expression among monocytes in hereditary CP as compared with those in idiopathic CP. The functional significance of CCR6 expression in CD4⁺ T cells was confirmed by flow cytometry and chemotaxis assay.

CONCLUSION

Single-cell sequencing with pancreatic immune cells in human CP highlights pancreas-specific immune crosstalk through the CCR6-CCL20 axis, a signalling pathway that might be leveraged as a potential future target in human hereditary CP.

Total Pancreatectomy with Islet Autotransplantation: New Insights on the Pathology and Pathogenesis of Chronic Pancreatitis from Tissue Research

Total pancreatectomy with islet autotransplantation (TPIAT) is a surgical procedure undertaken in some patients with severe pain or disability from recurrent acute and chronic pancreatitis (CP). TPIAT provides a rare opportunity to study human pancreas tissue from patients affected with pancreatitis, and particularly from patients with genetic forms of pancreatitis. Research to date suggests distinct histopathology and potentially differential pathophysiology of distinct etiologies of CP. Histopathology specimens have helped better define the success and limitations of clinical diagnostic imaging tools, such as magnetic retrograde cholangiopancreatography and endoscopic ultrasound.

In mouse chronic pancreatitis CD25+FOXP3+ regulatory T cells control pancreatic fibrosis by suppression of the type 2 immune response

Chronic pancreatitis (CP) is characterized by chronic inflammation and the progressive fibrotic replacement of exocrine and endocrine pancreatic tissue. We identify Treg cells as central regulators of the fibroinflammatory reaction by a selective depletion of FOXP3-positive cells in a transgenic mouse model (DEREG-mice) of experimental CP. In Treg-depleted DEREG-mice, the induction of CP results in a significantly increased stroma deposition, the development of exocrine insufficiency and significant weight loss starting from day 14 after disease onset. In CP, FOXP3⁺CD25⁺ Treg cells suppress the type-2 immune response by a repression of GATA3⁺ T helper cells (Th2), GATA3⁺ innate lymphoid cells type 2 (ILC2) and CD206⁺ M2-macrophages. A suspected pathomechanism behind the fibrotic tissue replacement may involve an observed dysbalance of Activin A expression in macrophages and of its counter regulator follistatin. Our study identified Treg cells as key regulators of the type-2 immune response and of organ remodeling during CP. The Treg/Th2 axis could be a therapeutic target to prevent fibrosis and preserve functional pancreatic tissue.

The function of T regulatory cells in the tissue fibrosis in chronic pancreatitis is not fully understood. Here the authors use a mouse model of chronic pancreatitis to show that Treg cells reduce IL-4 mediated chronic inflammation in the pancreas associated with M2-like macrophages in vivo.

Painful chronic pancreatitis - new approaches for evaluation and management

PURPOSE OF REVIEW

Management of abdominal pain in patients with chronic pancreatitis is often suboptimal. We review recent data on the epidemiology and new approaches for managing pain in chronic pancreatitis.

RECENT FINDINGS

Chronic pancreatitis duration does not appear to affect the pain experience. Pain pattern in chronic pancreatitis patients frequently changes and is not related to traditional patient and disease-related factors. Psychologic comorbidities, i.e. anxiety and depression, are frequent in patients with chronic pancreatitis, and are associated with more severe pain and pain interference. Adjunctive treatments, such as cognitive behavioral therapy, may positively influence pain management in chronic pancreatitis. Total pancreatectomy with islet autotransplantation (TPIAT) is an increasingly adopted treatment option in painful chronic pancreatitis. Ongoing multicenter studies will help define optimal candidates, predictors of successful pain remission and diabetes outcomes after TPIAT. Pancreatic quantitative sensory testing, a promising technique to interrogate nociception and sensory response, holds promise to identify patients with central sensitization. Initial studies show feasibility to stratify patients into defined pain profiles, and future studies will explore if these can help in prognostication of pain therapy.

SUMMARY

Several lines of investigations currently under evaluation are likely to have a positive impact on the management of pain in chronic pancreatitis.

Consortium for the study of chronic pancreatitis, diabetes, and pancreatic cancer: achievements and future directions

PURPOSE OF REVIEW

To answer several important clinical questions, the Consortium for the study of Chronic Pancreatitis, Diabetes, and Pancreatic Cancer (CPDPC) research consortium has established several ongoing clinical cohort studies focused on pancreatitis in adults and children, pancreatic cancer, and diabetes associated with pancreatic disease. These will provide a unique resource for clinical and basic science research into these hard-to-treat diseases.

RECENT FINDINGS

The cause, natural history, and prognosis of acute relapsing and chronic pancreatitis in adults and children are being delineated. The mechanisms of diabetes associated with chronic pancreatitis, acute pancreatitis, and pancreatic cancer are being defined. The ability to predict the presence of early-stage pancreatic cancer, thought the presence of new-onset diabetes, is being explored as a strategy to improve survival. The CPDPC is now also turning to developing clinically useful biomarkers, and initiating clinical trials in these difficult to treat pancreatic diseases.

SUMMARY

These large prospective patient cohorts, established and followed up by the CPDPC, provide a unique resource to improve the care of patients of all ages with pancreatitis, and to allow earlier diagnosis of pancreatic cancer.

Blood glucose regulation in context of infection

The immune and endocrine systems collectively control homeostasis in the body. The endocrine system ensures that values of essential factors and nutrients such as glucose, electrolytes and vitamins are maintained within threshold values. The immune system resolves local disruptions in tissue homeostasis, caused by pathogens or malfunctioning cells. The immediate goals of these two systems do not always align. The immune system benefits from optimal access to nutrients for itself and restriction of nutrient availability to all other organs to limit pathogen replication. The endocrine system aims to ensure optimal nutrient access for all organs, limited only by the nutrients stores that the body has available. The actual state of homeostatic parameters such as blood glucose levels represents a careful balance based on regulatory signals from the immune and endocrine systems. This state is not static but continuously adjusted in response to changes in the current metabolic needs of the body, the amount of resources it has available and the level of threats it encounters. This balance is maintained by the ability of the immune and endocrine systems to interact and co-regulate systemic metabolism. In context of metabolic disease, this system is disrupted, which impairs functionality of both systems. The failure of the endocrine system to retain levels of nutrients such as glucose within threshold values impairs functionality of the immune system. In addition, metabolic stress of organs in context of obesity is perceived by the immune system as a disruption in local homeostasis, which it tries to resolve by the excretion of factors which further disrupt normal metabolic control. In this chapter, we will discuss how the immune and endocrine systems interact under homeostatic conditions and during infection with a focus on blood glucose regulation. In addition, we will discuss how this system fails in the context of metabolic disease.

Macrophages in pancreatitis: Mechanisms and therapeutic potential

Macrophages play a crucial role in the pathogenesis of pancreatitis that is a common gastrointestinal disease. Particularly, macrophages differentiate into different phenotypes and exert diverse functions in acute pancreatitis (AP) and chronic pancreatitis (CP), respectively. In AP, macrophages in the pancreas and other related organs are mainly activated and differentiated into a pro-inflammatory M1 phenotype, and furthermore secrete inflammatory cytokines and mediators, causing local inflammation of the pancreas, and even intractable systemic inflammatory response or multiple organ failure. In CP, macrophages often exhibit a M2 polarisation and interact with pancreatic stellate cells (PSCs) in an autocrine and paracrine cytokine-dependent manner to promote the progression of pancreatic fibrosis. As the severity of pancreatic fibrosis aggravates, the proportion of M2/M1 macrophage cytokines in the pancreas increases. The discovery of macrophages in the pathogenesis of pancreatitis has promoted the research of targeted drugs, which provides great potential for the effective treatment of pancreatitis. This paper provides an overview of the roles of various macrophages in the pathogenesis of pancreatitis and the current research status of pancreatitis immunotherapy targeting macrophages. The findings addressed in this review are of considerable significance for understanding the pivotal role of macrophages in pancreatitis.

Alcohol and Smoking Mediated Modulations in Adaptive Immunity in Pancreatitis

Pancreatitis is a condition of pancreatic inflammation driven by injury to the pancreatic parenchyma. The extent of acinar insult, intensity, and type of immune response determines the severity of the disease. Smoking, alcohol and autoimmune pancreatitis are some of the predominant risk factors that increase the risk of pancreatitis by differentially influencing the adaptive immune system. The overall decrease in peripheral lymphocyte (T-, B- and (natural killer T-) NKT-cell) count and increased infiltration into the damaged pancreatic tissue highlight the contribution of adaptive immunity in the disease pathology. Smoking and alcohol modulate the responsiveness and apoptosis of T- and B-cells during pancreatic insult. Acute pancreatitis worsens with smoking and alcohol, leading to the development of systemic inflammatory response syndrome and compensatory anti-inflammatory response syndrome, suggesting the critical role of adaptive immunity in fatal outcomes such as multiple organ dysfunction. The presence of CD4⁺ and CD8⁺ T-lymphocytes and perforin-expressing cells in the fibrotic tissue in chronic pancreatitis modulate the severity of the disease. Due to their important role in altering the severity of the disease, attempts to target adaptive immune mediators will be critical for the development of novel therapeutic interventions.