The Impacts of Genetic and Environmental Factors on the Progression of Chronic Pancreatitis

Genetics and clinical implications of SPINK1 in the pancreatitis continuum and pancreatic cancer

Serine peptidase inhibitor, Kazal type 1 (SPINK1), a 56-amino-acid protein in its mature form, was among the first pancreatic enzymes to be extensively characterized biochemically and functionally. Synthesized primarily in pancreatic acinar cells and traditionally known as pancreatic secretory trypsin inhibitor, SPINK1 protects the pancreas by inhibiting prematurely activated trypsin. Since 2000, interest in SPINK1 has resurged following the discovery of genetic variants linked to chronic pancreatitis (CP). This review provides a historical overview of SPINK1's discovery, function, and gene structure before examining key genetic findings. We highlight three variants with well-characterized pathogenic mechanisms: c.-4141G > T, a causative enhancer variant linked to the extensively studied p.Asn34Ser (c.101A > G), which disrupts a PTF1L-binding site within an evolutionarily conserved HNF1A-PTF1L cis-regulatory module; c.194 + 2T > C, a canonical 5' splice site GT > GC variant that retains 10% of wild-type transcript production; and an Alu insertion in the 3'-untranslated region, which causes complete loss of function by forming extended double-stranded RNA structures with pre-existing Alu elements in deep intronic regions. We emphasize the integration of a full-length gene splicing assay (FLGSA) with SpliceAI's predictive capabilities, establishing SPINK1 the first disease gene for which the splicing impact of all possible coding variants was prospectively determined. Findings from both mouse models and genetic association studies support the sentinel acute pancreatitis event (SAPE) model, which explains the progression from acute pancreatitis to CP. Additionally, SPINK1 variants may contribute to an increased risk of pancreatic ductal adenocarcinoma (PDAC). Finally, we discuss the therapeutic potential of SPINK1, particularly through adeno-associated virus type 8 (AAV8)-mediated overexpression of SPINK1 as a strategy for treating and preventing pancreatitis, and highlight key areas for future research.

Associations between triglyceride-glucose related indices and the risk of incident pancreatic cancer: a large-scale prospective cohort study in the UK Biobank

BACKGROUND

Triglyceride-Glucose (TyG) index, a novel surrogate marker for insulin resistance, has been linked to the risk of various cancers, such as breast and colorectal cancers. However, the relationship between the TyG index and its related indices with the risk of pancreatic cancer(PC) remains unclear.

METHODS

This large-scale, prospective cohort study utilized data from the UK Biobank, involving 428,152 participants who were free of PC at baseline. The primary outcome was incident PC. To evaluate the relationships between TyG-related indices and PC onset, covariate-adjusted Cox proportional hazards regression models and restricted cubic spline (RCS) analyses were employed. Additionally, we explored the relationships between TyG-related indices and incident PC within subgroups defined by age, gender, diabetes, hypertension, pancreatitis history, smoking status, and drinking status. Sensitivity analyses were conducted to confirm the robustness of our findings.

RESULTS

Over an average follow-up period of 13.8 years, a total of 1,759 PC cases occurred. The risk of developing PC increased with higher levels of TyG-related indices. RCS curves illustrated a linear positive relationship between TyG-related indices and incident PC. Subgroup analyses indicated that the relationships between the TyG index, TyG-waist circumference, and TyG-waist-to-hip ratio and PC risk were more pronounced in participants without hypertension, without pancreatitis history, and those with drinking history (P for interaction < 0.05). Sensitivity analyses further validated the robustness of these findings.

CONCLUSIONS

TyG-related indices were independently related with a higher risk of incident PC, highlighting the importance of incorporating these indices into PC risk assessment tools and provides strong support for constructing a more comprehensive PC risk assessment framework.

Associations between ABO, FUT2 and chronic pancreatitis: A comprehensive meta-analysis of multiple cohorts and public biobanks

OBJECTIVES

Associations of ABO blood group specifying transferases A/B (ABO) and fucosyltransferase 2 (FUT2) with CP remain inconclusive. We aimed to comprehensively investigate the associations by Chinese sequencing cohorts and external cohorts.

METHODS

First, we analyzed the distributions of ABO blood groups and FUT2 status, along with lead single nucleotide polymorphisms (SNPs) at ABO (rs8176693 C/T) and FUT2 (rs632111 A/G) gene loci in Chinese low-coverage whole-genome sequencing discovery cohort. Subsequently, we investigated the associations of CP with ABO and FUT2 SNPs in Chinese whole-exome sequencing validation cohort and three public biobanks (FinnGen, UK Biobank, and BioBank Japan). Finally, comprehensive meta-analysis was performed by integrating data from two Chinese cohorts, reported cohorts and public biobanks.

RESULTS

Firstly, in Chinese discovery cohort, the distribution of blood types in CP patients showed no significant difference compared to healthy controls, and similar results were observed in subgroup analyses and in meta-analysis with the reported cohorts. Secondly, results indicated no association between rs8176693 or rs632111 and CP in Chinese cohorts and meta-analysis of three biobanks, though ABO SNP was found to be significantly associated with CP in UK Biobank (odds ratio [OR] = 1.27, P = 0.04). Finally, no association was observed between rs8176693 (OR = 1.03, P = 0.29) or rs632111 (OR = 1.04, P = 0.10) and CP in comprehensive meta-analysis.

CONCLUSIONS

No association was found between lead SNPs of ABO or FUT2 and CP in meta-analysis, nor was there an association between ABO blood group or FUT2 secretor status and CP in Chinese cohort. ABO and FUT2 might play limited role in CP development.

AKR1B10 and digestive tumors development: a review

Aldo-keto reductase family 1 member B10 (AKR1B10) is a member of the AKR1B subfamily. It is mainly found in cytoplasm, and it is typically expressed in the stomach and intestines. Given that its expression is low or absent in other tissues, AKR1B10 is a potential diagnostic and therapeutic biomarker for various digestive system diseases. Here, we review recent research progress on AKR1B10 in digestive system tumors such as hepatocellular carcinoma, gastric carcinoma, colorectal carcinoma, pancreatic carcinoma, oral squamous cell carcinoma, laryngeal squamous cell carcinoma, cholangiocarcinoma, and nasopharyngeal carcinoma, over the last 5 years. We also discuss the current trends and future research directions for AKR1B10 in both oncological and non-oncological diseases to provide a scientific reference for further exploration of this gene.

Germline multigene panel testing in acute and chronic pancreatitis

BACKGROUND/OBJECTIVES

Germline genetic testing is recommended for younger patients with idiopathic pancreatitis but there has been a lack of consensus in recommendations for those over age 35. We aimed to analyze the results of genetic testing among subjects of varying ages.

METHODS

Individuals who underwent germline multigene testing for pancreatitis susceptibility genes (CASR, CFTR, CPA1, CTRC, PRSS1, SPINK1) through a large commercial laboratory between 2017 and 2022 were included. Test results and information collected from test requisition forms were evaluated. Multivariable logistic regression models were performed to identify factors associated with a positive pancreatitis panel (pathogenic, likely pathogenic, and/or increased risk variants) in pancreatitis-related genes.

RESULTS

Overall, 2,468 subjects with primary indication of acute pancreatitis (AP) (n = 401), chronic pancreatitis (CP) (n = 631), pancreatic cancer (n = 128), or other indications (n = 1,308) completed germline testing. Among patients with AP or CP, the prevalence of any positive result for those <35 versus ≥35 years of age was 32.1% and 24.5% (p = 0.007), and the prevalence of a clinically meaningful result was 10.8% and 5.4%, respectively (p = 0.001). Positive family history of pancreatitis was associated with increased odds ratio (OR) of 8.59 (95% confidence interval (CI) 2.92-25.25) for a clinically significant panel result while each 5-year increase in age at test completion had lower odds (OR 0.89, 95% CI 0.83-0.95).

CONCLUSIONS

The highest prevalence of pathogenic variants is seen in younger individuals with a positive family history of pancreatitis. However, clinically meaningful results are identified in older subjects, suggesting that genetic counseling and testing should be considered for all age groups.

Genetic Factors Associated With Adverse Pregnancy Outcomes in Chronic Pancreatitis

INTRODUCTION

The effects of genetic factors on pregnancy outcomes in chronic pancreatitis (CP) patients remain unclear. We evaluated the impacts of clinical features and mutations in main CP-susceptibility genes ( SPINK1 , PRSS1 , CTRC , and CFTR ) on pregnancy outcomes in Chinese CP patients.

METHODS

This was a prospective cohort study with 14-year follow-up. The sample comprised female CP patients with documented pregnancy and known genetic backgrounds. Adverse pregnancy outcomes were compared between patients with and without gene mutations. Univariate and multivariate analyses were performed to determine the impact factors for adverse pregnancy outcomes.

RESULTS

Totally, 160 female CP patients with a pregnancy history were enrolled; 59.4% of patients carried pathogenic mutations in CP-susceptibility genes. Adverse pregnancy outcomes occurred in 38 patients (23.8%); the prevalence of adverse outcomes was significantly higher in those harboring gene mutations than those without (30.5% vs 13.8%, P = 0.015). Notably, the rates of preterm delivery (12.6% vs 3.1%, P = 0.036) and abortion (17.9% vs 4.6%, P = 0.013) were remarkably higher in patients with gene mutations (especially SPINK1 mutations) than those without. In multivariate analyses, both CP-susceptibility gene mutations (odds ratio, 2.52; P = 0.033) and SPINK1 mutations (odds ratio, 2.60; P = 0.037) significantly increased the risk of adverse pregnancy outcomes. Acute pain attack during pregnancy was another risk factor for adverse pregnancy outcomes.

DISCUSSION

Pathogenic mutations in CP-susceptibility genes, especially SPINK1 , were independently related to adverse pregnancy outcomes in CP patients. Significant attention should be paid to pregnant females harboring CP-susceptibility gene mutations (ClinicalTrials.gov: NCT06055595).

Metabolic Sequelae: The Pancreatitis Zeitgeist of the 21st Century

Holistic management of pancreatitis means that gastroenterologists in the 21st Century should think beyond improving in-hospital outcomes of pancreatitis alone. In particular, there is considerable room for optimizing the management of new-onset diabetes, exocrine pancreatic insufficiency, and other metabolic sequelae of pancreatitis. The present article provides state-of-the-art information on classification, terminology, and burden of the common sequelae of pancreatitis. A high-risk group of patients with pancreatitis is identified, which is positioned to benefit the most from the metabolic sequelae surveillance program introduced in this article. The program involves continuous follow-up after pancreatitis diagnosis, with the focus on early identification of new-onset diabetes after pancreatitis and exocrine pancreatic insufficiency. The metabolic sequelae surveillance program is scalable and has the potential to reduce the burden of pancreatitis through tertiary prevention in the decades to come.

Development of a clinical score to estimate pancreatitis-related hospital admissions in patients with a new diagnosis of chronic pancreatitis: the trinity score

BACKGROUND

The clinical course of chronic pancreatitis is unpredictable and there is no globally accepted score to predict the disease course. We developed a clinical score to estimate pancreatitis-related hospitalisation in patients with newly diagnosed chronic pancreatitis.

METHODS

We conducted a retrospective cohort study using two clinical chronic pancreatitis databases held in tertiary referral centres in Dublin, Ireland, and in Tarragona, Spain. Individuals diagnosed with chronic pancreatitis between 2007 and 2014 were eligible for inclusion. Candidate predictors included aetiology, body mass index, exocrine dysfunction, smoking and alcohol history. We used multivariable logistic regression to develop the model.

RESULTS

We analysed data from 154 patients with newly diagnosed chronic pancreatitis. Of these, 105 patients (68%) had at least one hospital admission for pancreatitis-related reasons in the 6 years following diagnosis. Aetiology of chronic pancreatitis, body mass index, use of pain medications and gender were found to be predictive of more pancreatic-related hospital admissions. These predictors were used to develop a clinical score which showed acceptable discrimination (area under the ROC curve = 0.70).

DISCUSSION

We developed a clinical score based on easily accessible clinical parameters to predict pancreatitis-related hospitalisation in patients with newly diagnosed chronic pancreatitis.

Causal associations between modifiable risk factors and pancreatitis: A comprehensive Mendelian randomization study

Background

The pathogenesis of pancreatitis involves diverse environmental risk factors, some of which have not yet been clearly elucidated. This study systematically investigated the causal effects of genetically predicted modifiable risk factors on pancreatitis using the Mendelian randomization (MR) approach.

Methods

Genetic variants associated with 30 exposure factors were obtained from genome-wide association studies. Summary-level statistical data for acute pancreatitis (AP), chronic pancreatitis (CP), alcohol-induced AP (AAP) and alcohol-induced CP (ACP) were obtained from FinnGen consortia. Univariable and multivariable MR analyses were performed to identify causal risk factors for pancreatitis.

Results

Genetic predisposition to smoking (OR = 1.314, P = 0.021), cholelithiasis (OR = 1.365, P = 1.307E-19) and inflammatory bowel disease (IBD) (OR = 1.063, P = 0.008) as well as higher triglycerides (OR = 1.189, P = 0.016), body mass index (BMI) (OR = 1.335, P = 3.077E-04), whole body fat mass (OR = 1.291, P = 0.004) and waist circumference (OR = 1.466, P = 0.011) were associated with increased risk of AP. The effect of obesity traits on AP was attenuated after correcting for cholelithiasis. Genetically-driven smoking (OR = 1.595, P = 0.005), alcohol consumption (OR = 3.142, P = 0.020), cholelithiasis (OR = 1.180, P = 0.001), autoimmune diseases (OR = 1.123, P = 0.008), IBD (OR = 1.066, P = 0.042), type 2 diabetes (OR = 1.121, P = 0.029), and higher serum calcium (OR = 1.933, P = 0.018), triglycerides (OR = 1.222, P = 0.021) and waist-to-hip ratio (OR = 1.632, P = 0.023) increased the risk of CP. Cholelithiasis, triglycerides and the waist-to-hip ratio remained significant predictors in the multivariable MR. Genetically predicted alcohol drinking was associated with increased risk of AAP (OR = 15.045, P = 0.001) and ACP (OR = 6.042, P = 0.014). After adjustment of alcohol drinking, genetic liability to IBD had a similar significant causal effect on AAP (OR = 1.137, P = 0.049), while testosterone (OR = 0.270, P = 0.002) a triglyceride (OR = 1.610, P = 0.001) and hip circumference (OR = 0.648, P = 0.040) were significantly associated with ACP. Genetically predicted higher education and household income levels could lower the risk of pancreatitis.

Conclusions

This MR study provides evidence of complex causal associations between modifiable risk factors and pancreatitis. These findings provide new insights into potential therapeutic and prevention strategies.

High Clinical and Genetic Similarity Between Chronic Pancreatitis Associated With Light-to-Moderate Alcohol Consumption and Classical Alcoholic Chronic Pancreatitis

Background and Aims

Heavy alcohol consumption and genetic factors represent the 2 major etiologies of chronic pancreatitis (CP). However, little is so far known about the clinical features and genetic basis of light-to-moderate alcohol consumption-related CP (LMA-CP).

Methods

A cross-sectional analysis was performed on 1061 Chinese CP patients between 2010 and 2015. CP was classified as classical alcoholic CP (ACP; n = 206), LMA-CP (n = 154), and idiopathic CP (ICP; n = 701). Clinical features and genetic characteristics (PRSS1, SPINK1, CTRC, CFTR variant status) were compared between the different groups. Odds ratios (ORs) with 95% confidence intervals were calculated to ascertain the combinatorial effect of alcohol consumption and gene mutation.

Results

Compared with ICP, the clinical features of LMA-CP were characterized by higher rates of developing pancreatic stones, pseudocyst, diabetes, and steatorrhea, which were similar to those associated with ACP. The prevalence of CP-related gene variants in LMA-CP was 38.3%, similar to ACP (39.8%), although significantly lower than ICP (56.2%). Alcohol consumption enhanced the risk of a poor clinical outcome, whereas genetic factors amplified alcohol's effects. Compared with ICP, LMA-CP and ACP were associated with a high risk of pancreatic stones (patients without variants, OR = 2.01 and 2.54; patients with variants, OR = 2.17 and 1.07), pseudocyst (patients without variants, OR = 1.03 and 1.43; patients with variants, OR = 1.67 and 2.14), diabetes mellitus (patients without variants, OR = 0.86 and 1.31; patients with variants, OR = 2.05 and 1.55), and steatorrhea (patients without variants, OR = 1.56 and 2.10; patients with variants, OR = 2.11 and 1.60).

Conclusion

Evidence was presented to show that LMA-CP was clinically and genetically similar to ACP but significantly different from ICP. Our findings provide support to the growing view that there is no safe level of alcohol consumption.

Expanding ACMG variant classification guidelines into a general framework

BACKGROUND

The American College of Medical Genetics and Genomics (ACMG)-recommended five variant classification categories (pathogenic, likely pathogenic, uncertain significance, likely benign, and benign) have been widely used in medical genetics. However, these guidelines are fundamentally constrained in practice owing to their focus upon Mendelian disease genes and their dichotomous classification of variants as being either causal or not. Herein, we attempt to expand the ACMG guidelines into a general variant classification framework that takes into account not only the continuum of clinical phenotypes, but also the continuum of the variants' genetic effects, and the different pathological roles of the implicated genes.

MAIN BODY

As a disease model, we employed chronic pancreatitis (CP), which manifests clinically as a spectrum from monogenic to multifactorial. Bearing in mind that any general conceptual proposal should be based upon sound data, we focused our analysis on the four most extensively studied CP genes, PRSS1, CFTR, SPINK1 and CTRC. Based upon several cross-gene and cross-variant comparisons, we first assigned the different genes to two distinct categories in terms of disease causation: CP-causing (PRSS1 and SPINK1) and CP-predisposing (CFTR and CTRC). We then employed two new classificatory categories, "predisposing" and "likely predisposing", to replace ACMG's "pathogenic" and "likely pathogenic" categories in the context of CP-predisposing genes, thereby classifying all pathologically relevant variants in these genes as "predisposing". In the case of CP-causing genes, the two new classificatory categories served to extend the five ACMG categories whilst two thresholds (allele frequency and functional) were introduced to discriminate "pathogenic" from "predisposing" variants.

CONCLUSION

Employing CP as a disease model, we expand ACMG guidelines into a five-category classification system (predisposing, likely predisposing, uncertain significance, likely benign, and benign) and a seven-category classification system (pathogenic, likely pathogenic, predisposing, likely predisposing, uncertain significance, likely benign, and benign) in the context of disease-predisposing and disease-causing genes, respectively. Taken together, the two systems constitute a general variant classification framework that, in principle, should span the entire spectrum of variants in any disease-related gene. The maximal compliance of our five-category and seven-category classification systems with the ACMG guidelines ought to facilitate their practical application.

Cigarette smoke toxin hydroquinone and misfolding pancreatic lipase variant cooperatively promote endoplasmic reticulum stress and cell death

Mutation-induced protein misfolding of pancreatic secretory enzymes and consequent endoplasmic reticulum stress can cause chronic pancreatitis. A recent study revealed that cigarette smoke also increases the risk of the disease through endoplasmic reticulum stress. Here, we investigated the cumulative cellular effect of the G233E misfolding human pancreatic lipase variant and hydroquinone; a main toxic constituent of cigarette smoke, using mammalian cell lines. We found that hydroquinone reduces cell viability on a dose-dependent manner through programmed cell death, and diminishes lipase secretion without affecting its expression. Interestingly, hydroquinone decreased the viability more markedly in cells expressing the G233E lipase variant, than in cells producing wild-type lipase. The more substantial viability loss was due to increased endoplasmic reticulum stress, as demonstrated by elevated levels of X-box binding protein 1 mRNA splicing and immunoglobulin binding protein, NAD(P)H:quinone oxidoreductase 1 and C/EBP homologous protein expression. Unresolved endoplasmic reticulum stress, and especially up-regulation of the pro-apoptotic transcription factor C/EBP homologous protein were likely responsible for the increased cell death. Our observations demonstrated that the combination of hydroquinone and misfolding pancreatic lipase variant promote increased levels of endoplasmic reticulum stress and cell death, which may predispose to chronic pancreatitis.

Functionally deficient TRPV6 variants contribute to hereditary and familial chronic pancreatitis

The recent discovery of TRPV6 as a pancreatitis susceptibility gene served to identify a novel mechanism of chronic pancreatitis (CP) due to Ca²⁺ dysregulation. Herein, we analyzed TRPV6 in 81 probands with hereditary CP (HCP), 204 probands with familial CP (FCP), and 462 patients with idiopathic CP (ICP) by targeted next-generation sequencing. We identified 25 rare nonsynonymous TRPV6 variants, 18 of which had not been previously reported. All 18 variants were characterized by a Ca²⁺ imaging assay, with 8 being identified as functionally deficient. Evaluation of functionally deficient variants in the three CP cohorts revealed two novel findings: (i) functionally deficient TRPV6 variants appear to occur more frequently in HCP/FCP patients than in ICP patients (3.2% vs. 1.5%) and (ii) functionally deficient TRPV6 variants found in HCP and FCP probands appear to be more frequently coinherited with known risk variants in SPINK1, CTRC, and/or CFTR than those found in ICP patients (66.7% vs 28.6%). Additionally, genetic analysis of available HCP and FCP family members revealed complex patterns of inheritance in some families. Our findings confirm that functionally deficient TRPV6 variants represent an important contributor to CP. Importantly, functionally deficient TRPV6 variants account for a significant proportion of cases of HCP/FCP.

Chronic Pancreatitis: The True Pathogenic Culprit within the SPINK1 N34S-Containing Haplotype Is No Longer at Large

A diverse range of loss-of-function variants in the SPINK1 gene (encoding pancreatic secretory trypsin inhibitor) has been identified in patients with chronic pancreatitis (CP). The haplotype harboring the SPINK1 c.101A>G (p.Asn34Ser or N34S) variant (rs17107315:T>C) is one of the most important heritable risk factors for CP as a consequence of its relatively high prevalence worldwide (population allele frequency ≈ 1%) and its considerable effect size (odds ratio ≈ 11). The causal variant responsible for this haplotype has been intensively investigated over the past two decades. The different hypotheses tested addressed whether the N34S missense variant has a direct impact on enzyme structure and function, whether c.101A>G could affect pre-mRNA splicing or mRNA stability, and whether another variant in linkage disequilibrium with c.101A>G might be responsible for the observed association with CP. Having reviewed the currently available genetic and experimental data, we conclude that c.-4141G>T (rs142703147:C>A), which disrupts a PTF1L-binding site within an evolutionarily conserved HNF1A-PTF1L cis-regulatory module located ∼4 kb upstream of the SPINK1 promoter, can be designated as the causal variant beyond reasonable doubt. This case illustrates the difficulties inherent in determining the identity of the causal variant underlying an initially identified disease association.