Genetics of acute and chronic pancreatitis: An update

Genetic Variability in the CPA1 Gene and Its Impact on Acute Pancreatitis Risk: New Insights from a Large-Scale Study

Acute pancreatitis (AP) is a common and potentially lethal disease. Over the last 10 years, AP has become one of the most important healthcare problems. On a global scale, the incidence has increased by 63% over the last 20 years. AP is usually caused by gallstones and excessive alcohol consumption and genetic factors play an important role in the development of inflammation. Recent studies involving the CPA1 mutations are ambiguous and dependent on the population studied. In this study, the variability of the CPA1 gene in patients with AP was analyzed. Genetic material was isolated from the blood of 301 patients with AP and 184 healthy individuals. Identification of the variants in exons 5, 6, 8, and 9 with introns was performed using molecular biology methods. Mutations were identified by comparison to the reference sequence (NM_001868.4). Statistical analysis included the identification of mutations correlating with the risk of AP, the etiology of inflammation, and family history. Several novel mutations in the CPA1 gene have been identified, along with a high degree of variability within the coding region of the carboxypeptidase gene. A correlation between mutations CPA1:c.1072 + 84del; c.987 + 57G>A and increased risk of developing AP was found. Two protective mutations, CPA1:c.625A>T, c.1072 + 94del, were identified. The CPA1 gene is characterized by high sequence variability and regions in which mutations lead to an increased risk of developing AP. Single or co-occurring mutations of the CPA1 gene can significantly affect the risk of developing AP.

Acute pancreatitis in childhood - a comparative international study and tale of two cities

BACKGROUNDS

To compare factor(s) contributing to aetiology, management and clinical outcome(s) of paediatric patients acquiring acute pancreatitis (AP) at two major university paediatric surgical centres in Liverpool and Bangkok.

METHODS

All patients (<18 years) with an index diagnosis of AP (ICD 10 coding) during 2006-2016 were studied.

RESULTS

121 patients included n = 79 (65.3%) in Thailand versus n = 42 (34.7%) in the UK centre with no difference(s) in age at diagnosis at 10.4 ± 4.5 and 11.7 ± 6 years. (P = 0.12). Major AP aetiology(s) in Thailand were medications (39.2%) and choledochal cysts (8.9%). In the UK-gallstone disease (21.4%), and medications (16.7%) were leading factors (P < 0.01). Ultrasonography was deployed more frequently in the UK versus Thai centre (74.3% vs. 49.1%; P < 0.01). Pancreatitis was confirmed by imaging in 67.9% (Thai) and 62.9% (UK) patients (P = 0.47). Most patients at both centres had a mild-grade pancreatitis illness (95% Thai vs. 90.5% UK; P = 0.28) while 12.7% of Thai and 19% of UK children developed pancreatitis-related complication (P = 0.37). Overall mortality rate (%) was significantly higher in the Thai versus UK centre (27.8% vs. 9.5%; P = 0.02).

CONCLUSIONS

Aetiology of acute pancreatitis appears to vary between UK and Thailand children. Timely early diagnosis and healthcare pathways may be driven by local patient-related factor(s). The higher mortality (%) observed in Thailand versus UK in this comparative study was linked to underlying co-existent chronic medical condition(s) in vulnerable patient cohorts.

Surgical management of acute pancreatitis: Historical perspectives, challenges, and current management approaches

Acute pancreatitis (AP) is a serious condition presenting catastrophic consequences. In severe AP, the mortality rate is high, and some patients initially diagnosed with mild-to-moderate AP can progress to a life-threatening severe state. Treatment of AP has evolved over the years. Drainage was the first surgical procedure performed for AP; however, later, surgical approaches were replaced by more conservative approaches due to the availability of advanced medical care and improved understanding of the course of AP. Currently, surgery is used to manage several complications of AP, such as pseudocysts, pancreatic fistulas, and biliary tract obstruction. Patients who are unresponsive to conservative treatment or have complications are typically considered for surgical intervention. This review focuses on the surgical approaches (endoscopic, percutaneous, and open) that have been established in recent studies to treat this acute condition and summarizes the common management guidelines for AP, discussing the relevant indications, significance, and complications. It is evident that despite their reduced involvement, surgeons lead the multidisciplinary care of patients with AP; however, given the gaps in existing knowledge, more research is required to standardize surgical protocols for AP.

An investigation of codon usage pattern analysis in pancreatitis associated genes

BACKGROUND

Pancreatitis is an inflammatory disorder resulting from the autoactivation of trypsinogen in the pancreas. The genetic basis of the disease is an old phenomenon, and evidence is accumulating for the involvement of synonymous/non-synonymous codon variants in disease initiation and progression.

RESULTS

The present study envisaged a panel of 26 genes involved in pancreatitis for their codon choices, compositional analysis, relative dinucleotide frequency, nucleotide disproportion, protein physical properties, gene expression, codon bias, and interrelated of all these factors. In this set of genes, gene length was positively correlated with nucleotide skews and codon usage bias. Codon usage of any gene is dependent upon its AT and GC component; however, AGG, CGT, and CGA encoding for Arg, TCG for Ser, GTC for Val, and CCA for Pro were independent of nucleotide compositions. In addition, Codon GTC showed a correlation with protein properties, isoelectric point, instability index, and frequency of basic amino acids. We also investigated the effect of various evolutionary forces in shaping the codon usage choices of genes.

CONCLUSIONS

This study will enable us to gain insight into the molecular signatures associated with the disease that might help identify more potential genes contributing to enhanced risk for pancreatitis. All the genes associated with pancreatitis are generally associated with physiological function, and mutations causing loss of function, over or under expression leads to an ailment. Therefore, the present study attempts to envisage the molecular signature in a group of genes that lead to pancreatitis in case of malfunction.

Pancreas Divisum Increases the Risk of Recurrent Acute Pancreatitis in Patients with rs12338 Polymorphism in the Cathepsin B Gene

OBJECTIVES

Pancreas divisum (PD) as a cause of pancreatitis has been debated. In this study, we report the association of multiple gene polymorphisms on the risk of RAP in the presence of PD.

DESIGN

We enrolled 687 individuals (167 IRAP, 276 ICP, and 244 unrelated healthy controls) from May 2015 to September 2016. Patients were divided into those with/without PD. Associations between the significantly prevalent SNPs and IRAP/ICP in the presence of PD were evaluated. Clinical data were analyzed using Mann-Whitney U/Chi-square test. Effect size of association of SNPs with IRAP/ICP was expressed as odds ratio (OR) (95% CI). Gene-gene interaction was assessed by transheterozygosity analyses. Bonferroni-corrected two-tailed "p" value of ≤ 0.01 was considered statistically significant.

RESULTS

Thirty-three (19.8%) and 82 (29.7%) patients with IRAP and ICP, respectively, had PD. Among the patients with IRAP, duration of disease was significantly shorter in those with PD compared to those without (mean [95% CI] duration: 1.6 (1.3-1.9) vs 2.7 (2.3-3.1) years; p = 0.005). There were no differences in gender, race, and diabetes among patients with/without PD in IRAP/ICP groups. Mean (95% CI) pancreatic duct diameter (mm) was significantly higher in the presence of PD in patients with both IRAP [1.6 (1.4-1.9) v/s 1.29 (1.2-1.4); p = 0.03)] and ICP [5.2 (4.5-5.9) v/s 4.5 (3.9-5.1); p = 0.02]. CTSB (rs12338) polymorphisms were significantly associated with IRAP [OR (95% CI) 2.44 (1.41-4.22); p = 0.001] among patients with PD. No association was observed with ICP. Transheterozygosity analysis did not show any significant associations of combination of SNPs with IRAP in the presence of PD.

CONCLUSION

Risk of RAP due to PD increases in patients with rs12338 polymorphism in the cathepsin B gene.

The TLC-Bioautography as a Tool for Rapid Enzyme Inhibitors detection - A Review

Microorganisms and plants can be important sources of many compounds with potential pharmaceutical applications. Extraction of these matrices is one of the ways of identifying the presence of inhibitory active substances against enzymes whose high activity leads to serious human diseases including cancer, Parkinson's or Crohn's diseases. The isolation and purification of inhibitors are time-consuming and expensive steps in the analysis of the crude extract and therefore, it is necessary to find a fast, efficient, and inexpensive method for screening extracts of interest. TLC-Bioautography combines the separation of the extract on a thin layer with its subsequent biological analysis. TLC-Bioautography methods have been developed for several classes of enzymes including oxidoreductases, hydrolases and isomerases, and there is a potential for developing functional methods for other classes of enzymes. This review summarizes known TLC-Bioautography methods and their applications for determining the presence of enzyme inhibitors in extracts and compares the effectiveness of different methodological approaches. It also indicates the current state and perspective of the development of TLC-Bioautography and its possible future applications.

Transgenic Expression of PRSS1R122H Sensitizes Mice to Pancreatitis

BACKGROUND & AIMS

Mutations in the trypsinogen gene (PRSS1) cause human hereditary pancreatitis. However, it is not clear how mutant forms of PRSS1 contribute to disease development. We studied the effects of expressing mutant forms of human PRSS1 in mice.

METHODS

We expressed forms of PRSS1 with and without the mutation encoding R122H (PRSS1R122H) specifically in pancreatic acinar cells under control of a full-length pancreatic elastase gene promoter. Mice that did not express these transgenes were used as controls. Mice were given injections of caerulein to induce acute pancreatitis or injections of lipopolysaccharide to induce chronic pancreatitis. Other groups of mice were fed ethanol or placed on a high-fat diet to induce pancreatitis. Pancreata were collected and analyzed by histology, immunoblots, real-time polymerase chain reaction, and immunohistochemistry. Trypsin enzymatic activity and chymotrypsin enzymatic activity were measured in pancreatic homogenates. Blood was collected and serum amylase activity was measured.

RESULTS

Pancreata from mice expressing transgenes encoding PRSS1 or PRSS1R122H had focal areas of inflammation; these lesions were more prominent in mice that express PRSS1R122H. Pancreata from mice that express PRSS1 or PRSS1R122H had increased levels of heat shock protein 70 and nuclear factor (erythroid-derived 2)-like 2, and reduced levels of chymotrypsin C compared with control mice. Increased expression of PRSS1 or PRSS1R122H increased focal damage in pancreatic tissues and increased the severity of acute pancreatitis after caerulein injection. Administration of lipopolysaccharide exacerbated inflammation in mice that express PRSS1R122H compared to mice that express PRSS1 or control mice. Mice that express PRSS1R122H developed more severe pancreatitis after ethanol feeding or a high-fat diet than mice that express PRSS1 or control mice. Pancreata from mice that express PRSS1R122H had more DNA damage, apoptosis, and collagen deposition and increased trypsin activity and infiltration by inflammatory cells than mice that express PRSS1 or control mice.

CONCLUSIONS

Expression of a transgene encoding PRSS1R122H in mice promoted inflammation and increased the severity of pancreatitis compared with mice that express PRSS1 or control mice. These mice might be used as a model for human hereditary pancreatitis and can be studied to determine mechanisms of induction of pancreatitis by lipopolysaccharide, ethanol, or a high-fat diet.

Observational longitudinal multicentre investigation of acute pancreatitis (GOULASH PLUS): follow-up of the GOULASH study, protocol

BACKGROUND

Acute pancreatitis (AP) is an inflammatory condition that can lead to late consequences. Recurrent AP (RAP) develops in 20% of patients and chronic pancreatitis (CP) occurs in 7%-12.8%. However, we do not have sufficient information to establish an evidence-based statement to define early CP, or how to prevent its development.

AIM

The aim of this study was to understand the influencing factors and to determine which parameters should be measured or used as a biomarker to detect the early phase of CP.

METHODS/DESIGN

This is an observational prospective follow-up study of the GOULASH-trial (ISRTCN 63827758) in which (1) all severity of pancreatitis are included; (2) patients receive only therapeutic modalities which are accepted by the evidence based medicine (EBM) guideline; (3) whole blood, serum and plasma samples are stored in our biobank; and (4) large amount of variables are collected and kept in our electronic database including anamnestic data, physical examination, laboratory parameters, imaging, therapy and complications. Therefore, this fully characterised patient cohort are well suitable for this longitudinal follow-up study. Patients' selection: patients enrolled in the GOULASH study will be offered to join to the longitudinal study. The follow-up will be at 1, 2, 3, 4, 5 and 6 years after the episode of AP. Anamnestic data will be collected by questionnaires: (1) diet history questionnaire, (2) 36-Item Short-Form Health Survey, (3) physical activity questionnaire and (4) stress questionnaire. Genetic tests will be performed for the genes associated with CP. The exocrine and endocrine pancreatic, liver and kidney functions will be determined by laboratory tests, stool sample analyses and imaging. Cost-effectiveness will be analysed to examine the relationship between events of interest and health-related quality of life or to explore subgroup differences.

CONCLUSION

This study will provide information about the risk and influencing factors leading to CP and identify the most useful measurable parameters.

TRIAL REGISTRATION NUMBER

ISRCTN63396106.

Next-Generation Sequencing in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is lethal, and the majority of patients present with locally advanced or metastatic disease that is not amenable to cure. Thus, with surgical resection being the only curative modality, it is critical that disease is identified at an earlier stage to allow the appropriate therapy to be applied. Unfortunately, a specific biomarker for early diagnosis has not yet been identified; hence, no screening process exists. Recently, high-throughput screening and next-generation sequencing (NGS) have led to the identification of novel biomarkers for many disease processes, and work has commenced in PDAC. Genomic data generated by NGS not only have the potential to assist clinicians in early diagnosis and screening, especially in high-risk populations, but also may eventually allow the development of personalized treatment programs with targeted therapies, given the large number of gene mutations seen in PDAC. This review introduces the basic concepts of NGS and provides a comprehensive review of the current understanding of genetics in PDAC as related to discoveries made using NGS.

Glycemic Outcomes of Islet Autotransplantation

PURPOSE OF REVIEW

While there has been a growing utilization of total pancreatectomy with islet autotransplantation (TPIAT) for patients with medically refractory chronic pancreatitis over the past few decades, there remains a lack of consensus clinical guidelines to inform the counseling and management of patients undergoing TPIAT. In this article, we review the current clinical practice and published experience of several TPIAT centers, outline key aspects in managing patients undergoing TPIAT, and discuss the glycemic outcomes of this procedure.

RECENT FINDINGS

Aiming for lower inpatient glucose targets immediately after surgery (usually 100-120 mg/dl), maintaining all patients on subcutaneous insulin for at least 3 months to "rest" islets before an attempt is made to wean insulin, and close outpatient endocrinology follow-up after TPIAT particularly in the first year is common and related to better outcomes. Although TPIAT procedures and glycemic outcomes may differ across surgical centers, overall, approximately one third of patients are insulin independent at 1 year after TPIAT. Higher islet yield and lower preoperative glucose levels are among the strongest predictors of short-term post-operative insulin independence. Beyond 1 year post-operatively, the clinical management and long-term glycemic outcomes of patients after TPIAT are more variable. A multidisciplinary approach is essential in optimizing the preoperative, inpatient, and post-operative management and counseling of patients about the expected glycemic outcomes after surgery. Consensus guidelines for the clinical management of diabetes after TPIAT and harmonization of data collection protocols among TPIAT centers are needed to address the current knowledge gaps in clinical care and research and to optimize glycemic outcomes after TPIAT.

Common variants in the CLDN2-MORC4 and PRSS1-PRSS2 loci confer susceptibility to acute pancreatitis

BACKGROUND/OBJECTIVES

Acute pancreatitis (AP) is one of the most common gastrointestinal disorders often requiring hospitalization. Frequent aetiologies are gallstones and alcohol abuse. In contrast to chronic pancreatitis (CP) few robust genetic associations have been described. Here we analysed whether common variants in the CLDN2-MORC4 and the PRSS1-PRSS2 locus that increase recurrent AP and CP risk associate with AP.

METHODS

We screened 1462 AP patients and 3999 controls with melting curve analysis for SNPs rs10273639 (PRSS1-PRSS2), rs7057398 (RIPPLY), and rs12688220 (MORC4). Calculations were performed for the overall group, aetiology, and gender sub-groups. To examine genotype-phenotype relationships we performed several meta-analyses.

RESULTS

Meta-analyses of all AP patients depicted significant (p-value < 0.05) associations for rs10273639 (odds ratio (OR) 0.88, 95% confidence interval (CI) 0.81-0.97, p-value 0.01), rs7057398 (OR 1.27, 95% CI 1.07-1.5, p-value 0.005), and rs12688220 (OR 1.32, 95% CI 1.12-1.56, p-value 0.001). For the different aetiology groups a significant association was shown for rs10273639 (OR 0.76, 95% CI 0.63-0.92, p-value 0.005), rs7057398 (OR 1.43, 95% CI 1.07-1.92, p-value 0.02), and rs12688220 (OR 1.44, 95% CI 1.07-1.93, p-value 0.02) in the alcoholic sub-group only.

CONCLUSIONS

The association of CP risk variants with different AP aetiologies, which is strongest in the alcoholic AP group, might implicate common pathomechanisms most likely between alcoholic AP and CP.

Pancreatic Aquaporin-7: A Novel Target for Anti-diabetic Drugs?

Aquaporins comprise a family of 13 members of water channels (AQP0-12) that facilitate a rapid transport of water across cell membranes. In some cases, these pores are also permeated by small solutes, particularly glycerol, urea or nitric oxide, among other solutes. Several aquaporins have been identified in the pancreas, an exocrine and endocrine organ that plays an essential role in the onset of insulin resistance and type 2 diabetes. The exocrine pancreas, which accounts for 90% of the total pancreas, secretes daily large volumes of a near-isotonic fluid containing digestive enzymes into the duodenum. AQP1, AQP5, and AQP8 contribute to fluid secretion especially from ductal cells, whereas AQP12 allows the proper maturation and exocytosis of secretory granules in acinar cells of the exocrine pancreas. The endocrine pancreas (10% of the total pancreatic cells) is composed by the islets of Langerhans, which are distributed in α, β, δ, ε, and pancreatic polypeptide (PP) cells that secrete glucagon, insulin, somatostatin, ghrelin and PP, respectively. AQP7, an aquaglyceroporin permeated by water and glycerol, is expressed in pancreatic β-cells and murine studies have confirmed its participation in insulin secretion, triacylglycerol synthesis and proliferation of these endocrine cells. In this regard, transgenic AQP7-knockout mice develop adult-onset obesity, hyperinsulinemia, increased intracellular triacylglycerol content and reduced β-cell mass in Langerhans islets. Moreover, we have recently reported that AQP7 upregulation in β-cells after bariatric surgery, an effective weight loss surgical procedure, contributes, in part, to the improvement of pancreatic steatosis and insulin secretion through the increase of intracytoplasmic glycerol in obese rats. Human studies remain scarce and controversial, with some rare cases of loss-of function mutations of the AQP7 gene being associated with the onset of type 2 diabetes. The present Review is focused on the role of aquaporins in the physiology and pathophysiology of the pancreas, highlighting the role of pancreatic AQP7 as a novel player in the control of β-cell function and a potential anti-diabetic-drug.

The Dutch Pancreas Biobank Within the Parelsnoer Institute: A Nationwide Biobank of Pancreatic and Periampullary Diseases

OBJECTIVES

Large biobanks with uniform collection of biomaterials and associated clinical data are essential for translational research. The Netherlands has traditionally been well organized in multicenter clinical research on pancreatic diseases, including the nationwide multidisciplinary Dutch Pancreatic Cancer Group and Dutch Pancreatitis Study Group. To enable high-quality translational research on pancreatic and periampullary diseases, these groups established the Dutch Pancreas Biobank.

METHODS

The Dutch Pancreas Biobank is part of the Parelsnoer Institute and involves all 8 Dutch university medical centers and 5 nonacademic hospitals. Adult patients undergoing pancreatic surgery (all indications) are eligible for inclusion. Preoperative blood samples, tumor tissue from resected specimens, pancreatic cyst fluid, and follow-up blood samples are collected. Clinical parameters are collected in conjunction with the mandatory Dutch Pancreatic Cancer Audit.

RESULTS

Between January 2015 and May 2017, 488 patients were included in the first 5 participating centers: 4 university medical centers and 1 nonacademic hospital. Over 2500 samples were collected: 1308 preoperative blood samples, 864 tissue samples, and 366 follow-up blood samples.

CONCLUSIONS

Prospective collection of biomaterials and associated clinical data has started in the Dutch Pancreas Biobank. Subsequent translational research will aim to improve treatment decisions based on disease characteristics.

Pancreatic adenocarcinoma, chronic pancreatitis, and MODY-8 diabetes: is bile salt-dependent lipase (or carboxyl ester lipase) at the crossroads of pancreatic pathologies?

Pancreatic adenocarcinomas and diabetes mellitus are responsible for the deaths of around two million people each year worldwide. Patients with chronic pancreatitis do not die directly of this disease, except where the pathology is hereditary. Much current literature supports the involvement of bile salt-dependent lipase (BSDL), also known as carboxyl ester lipase (CEL), in the pathophysiology of these pancreatic diseases. The purpose of this review is to shed light on connections between chronic pancreatitis, diabetes, and pancreatic adenocarcinomas by gaining an insight into BSDL and its variants. This enzyme is normally secreted by the exocrine pancreas, and is diverted within the intestinal lumen to participate in the hydrolysis of dietary lipids. However, BSDL is also expressed by other cells and tissues, where it participates in lipid homeostasis. Variants of BSDL resulting from germline and/or somatic mutations (nucleotide insertion/deletion or nonallelic homologous recombination) are expressed in the pancreas of patients with pancreatic pathologies such as chronic pancreatitis, MODY-8, and pancreatic adenocarcinomas. We discuss the possible link between the expression of BSDL variants and these dramatic pancreatic pathologies, putting forward the suggestion that BSDL and its variants are implicated in the cell lipid metabolism/reprogramming that leads to the dyslipidemia observed in chronic pancreatitis, MODY-8, and pancreatic adenocarcinomas. We also propose potential strategies for translation to therapeutic applications.

Pancreatitis after human papillomavirus vaccination: a matter of molecular mimicry

A 20-year-old man developed severe abdominal pain 1 week after being vaccinated with the first dose of quadrivalent human papillomavirus (HPV) vaccine (Gardasil^®). Despite ongoing symptoms of nausea and pain, he received the second dose of the vaccine. Only 10 days later, laboratory results revealed significantly elevated pancreatic enzymes, and with concomitant abdominal pain and vomiting, he was diagnosed with acute pancreatitis. This case of acute pancreatitis after HPV vaccination is not a novel entity. Although confirming the relationship between pancreatitis and vaccine is challenging, some factors suggest a possible link, including the positive re-challenge upon repeated exposure to the vaccine, HPV vaccine as probable causal relationship to other autoimmune diseases and a probable mechanism of molecular mimicry. In conjunction with aluminum adjuvant, the induction of immunity through molecular mimicry may potentially culminate in production of cytotoxic autoantibodies with a particular affinity for pancreatic acinar cells.

The role of the carboxyl ester lipase (CEL) gene in pancreatic disease

The enzyme carboxyl ester lipase (CEL), also known as bile salt-dependent or -stimulated lipase (BSDL, BSSL), hydrolyzes dietary fat, cholesteryl esters and fat-soluble vitamins in the duodenum. CEL is mainly expressed in pancreatic acinar cells and lactating mammary glands. The human CEL gene resides on chromosome 9q34.3 and contains a variable number of tandem repeats (VNTR) region that encodes a mucin-like protein tail. Although the number of normal repeats does not appear to significantly influence the risk for pancreatic disease, single-base pair deletions in the first VNTR repeat cause a syndrome of endocrine and exocrine dysfunction denoted MODY8. Hallmarks are low fecal elastase levels and pancreatic lipomatosis manifesting before the age of twenty, followed by development of diabetes and pancreatic cysts later in life. The mutant protein forms intracellular and extracellular aggregates, suggesting that MODY8 is a protein misfolding disease. Recently, a recombined allele between CEL and its pseudogene CELP was discovered. This allele (CEL-HYB) encodes a chimeric protein with impaired secretion increasing five-fold the risk for chronic pancreatitis. The CEL gene has proven to be exceptionally polymorphic due to copy number variants of the CEL-CELP locus and alterations involving the VNTR. Genome-wide association studies or deep sequencing cannot easily pick up this wealth of genetic variation. CEL is therefore an attractive candidate gene for further exploration of links to pancreatic disease.

Targeted Gene Next-Generation Sequencing in Chinese Children with Chronic Pancreatitis and Acute Recurrent Pancreatitis

OBJECTIVE

To identify causal mutations in certain genes in children with acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP).

STUDY DESIGN

After patients were enrolled (CP, 55; ARP, 14) and their clinical characteristics were investigated, we performed next-generation sequencing to detect nucleotide variations among the following 10 genes: cationic trypsinogen protease serine 1 (PRSS1), serine protease inhibitor, Kazal type 1 (SPINK1), cystic fibrosis transmembrane conductance regulator gene (CFTR), chymotrypsin C (CTRC), calcium-sensing receptor (CASR), cathepsin B (CTSB), keratin 8 (KRT8), CLAUDIN 2 (CLDN2), carboxypeptidase A1 (CPA1), and ATPase type 8B member 1 (ATP8B1). Mutations were searched against online databases to obtain information on the cause of the diseases. Certain novel mutations were analyzed using the SIFT2 and Polyphen-2 to predict the effect on protein function.

RESULTS

There were 45 patients with CP and 10 patients with ARP who harbored 1 or more mutations in these genes; 45 patients had at least 1 mutation related to pancreatitis. Mutations were observed in the PRSS1, SPINK1, and CFTR genes in 17 patients, the CASR gene in 5 patients, and the CTSB, CTRC, and KRT8 genes in 1 patient. Mutations were not found in the CLDN, CPA1, or ATP8B1 genes. We found that mutations in SPINK1 may increase the risk of pancreatic duct stones (OR, 11.07; P = .003). The patients with CFTR mutations had a higher level of serum amylase (316.0 U/L vs 92.5 U/L; P = .026).

CONCLUSION

Mutations, especially those in PRSS1, SPINK1, and CFTR, accounted for the major etiologies in Chinese children with CP or ARP. Children presenting mutations in the SPINK1 gene may have a higher risk of developing pancreatic duct stones.

CTRC gene polymorphism may increase pancreatic cancer risk – preliminary study

Pancreatic cancer is often fatal due to delayed diagnosis and treatment difficulties. Objective: To analyze selected SPINK1, CTRC, CFTR, and PRSS1 gene mutations in cancer tissue and blood samples of patients with pancreatic tumors. Materials and method: We enrolled 16 consecutive patients diagnosed with pancreatic tumors. We collected cancer tissue, normal pancreatic tissue, and blood samples for genetic tests. The control group consisted of 419 healthy individuals. Peripheral blood samples were collected from all study participants in EDTA-coated tubes. Results: Out of 16 patients with pancreatic tumors, 12 had pancreatic cancer on microscopic examination (mean age, 60.2 years). The CTRC polymorphism Hetero p.G60=(c.180C>T) was found in 5 patients with pancreatic cancer (41.7% vs. 18.6% in the control group). One patient with pancreatic cancer and a positive family history had the SPINK1 (p.N34S) mutation [8.3% vs. 2.9% (12/419) in the control group]. One patient with pancreatic cancer had the CTRC (p.R254W) mutation [8.3% vs. 1% (4/419) in the control group]. Conclusions: Our preliminary results show that the CTRC polymorphism p.G60= (c.180C>T) is frequent in patients with pancreatic cancer. However, further research is needed to verify our findings.

Immunology of pancreatitis and environmental factors

PURPOSE OF REVIEW

This report reviews recent aspects of pancreatitis immunology and environmental factors that link to development and progression of disease.

RECENT FINDINGS

Limited human and animal model studies have recently attempted to understand immune mechanisms that lead to the pathogenesis of acute and chronic pancreatitis. Based on these studies innate immune responses emerge as critical elements in disease pathogenesis and severity of inflammation. The immune basis for environmental factors such as smoking, which are highly associated with disease progression highlight novel cross talk mechanisms between immune and nonimmune pancreatic cells such as the pancreatic stellate cells.

SUMMARY

Better understanding of immune responses and signaling pathways are emerging as important contributors in pancreatitis development and progression. Such mechanisms are likely to offer future targetable therapies that can either halt or reverse disease progression.

Meta-analysis of the impact of SPINK1 p.N34S gene variation in Caucasic patients with chronic pancreatitis. An update

BACKGROUND

SPINK1 p.N34S gene variation is one of the endogenous factors which seem to be associated with chronic pancreatitis (CP). However, in literature there is no clear agreement regarding its contribution in different ethnicity and CP etiologies.

AIM

To investigate the role of SPINK1 p.N34S gene variation in CP patients with European origin by means of meta-analysis.

METHODS

Literature search was conducted and case-control studies evaluating Caucasian population, published between May 2007 and May 2015, were included. We also included Caucasian selected studies analyzed in previous meta-analysis. We carried out meta-analysis including all selected studies. After that, we performed two additional meta-analyses considering the incidence of SPINK1 p.N34S gene variation in alcoholic or in idiopathic CP patients vs control group.

RESULTS

Twenty-five studies were included and the total number of subjects was 8800 (2981 cases and 5819 controls). The presence of p.N34S variation increased nine times the overall CP risk in population of European origin [OR 9.695 (CI 95% 7.931-11.851)]. Also, the contribution of SPINK1 in idiopathic pancreatitis [OR 13.640 (CI 95% 8.858-21.002)] was found to be higher than in alcoholic CP [5.283 (CI 95% 3.449-8.092)].

CONCLUSION

The association between SPINK1 p.N34S gene variation and CP is confirmed. Also, we confirmed that the idiopathic etiology needs a better definition by means of genetic analysis.

Alcohol Consumption and Cigarette Smoking are Important Modifiers of the Association Between Acute Pancreatitis and the PRSS1-PRSS2 Locus in Men

OBJECTIVES

The present study was designed to investigate whether the susceptibility to acute pancreatitis (AP) attributable to polymorphism rs10273639 at the PRSS1-PRSS2 locus is dependent on alcohol consumption and cigarette smoking.

METHODS

A total of 603 unrelated Russian individuals including 304 patients with physician-diagnosed AP and 299 sex- and age-matched healthy controls have been recruited for the study. A polymorphism rs10273639 (-408C>T) of PRSS1-PRSS2 was genotyped by TaqMan-based assay.

RESULTS

A variant allele -408T (P = 0.003) and genotypes -408CT plus TT (P = 0.002) were associated with decreased AP risk only in men. The odds ratios for AP in the CC homozygotes versus the variant genotypes were 1.95 [95% confidence interval (CI), 0.65-5.85; P = 0.23], 1.72 (95% CI, 0.93-3.20; P = 0.08), and 2.37 (95% CI, 1.09-5.13; P = 0.03) for men who consumed up to 28, 29 to 59, and more than 60 alcohol drinks a week, respectively. Cigarette smokers with the -408CC genotype had an increased risk of AP (odds ratio, 2.07; 95% CI, 1.25-3.42; P = 0.004), whereas nonsmoker carriers did not have a disease risk (odds ratio, 1.48; 95% CI, 0.58-3.82; P = 0.42).

CONCLUSIONS

We confirmed a robust association of polymorphism rs10273639 at PRSS1-PRSS2 with AP in the Russian population. The present study is the first to show that relationship between the locus and disease is significantly modified by alcohol consumption and cigarette smoking.

CTRC gene polymorphism (p.G60=; c.180 C > T) in acute pancreatitis

BACKGROUND

The aim of the study was to determine the relationship between the presence of p.G60 = polymorphism (c.180C > T; rs497078) CTRC and the incidence together with the clinical course of acute pancreatitis (AP).

METHODS

Two hundred ninety-nine people suffering from AP and 417 healthy volunteers were subjected to the study. DNA was isolated from blood samples.

RESULTS

CTRC p.G60 = polymorphism (c.180C > T) occurred more frequently in the AP group (p = 0.015). The CT and TT genotype was found in 27.8% of the AP patients and in 19.9% of the healthy subjects (p = 0.017). No significant correlation was found between having the CT and TT genotype and the severity of the AP clinical course. In 6 patients (2%) with the CT genotype, a SPINK1 gene mutation was found, while in the control group it was found in 3 patients (0.7%), (p > 0.05). All patients with the present SPINK1 mutation with the CT genotype had a moderate or a severe course of the disease (p = 0.0007).

CONCLUSIONS

CTRC polymorphism Hetero p.G60=; c.180C > T increases the risk of an AP occurrence and together with the SPINK 1 mutation, may be responsible for a more severe course of the disease.

Genetic Susceptibility in Acute Pancreatitis: Genotyping of GSTM1, GSTT1, GSTP1, CASP7, CASP8, CASP9, CASP10, LTA, TNFRSF1B, and TP53 Gene Variants

OBJECTIVES

Genetic testing could play a critical role in diagnosis and prognosis of acute pancreatitis (AP) and guide effective therapeutic interventions. We hypothesized that genetic polymorphisms in apoptosis and oxidative stress genes could determine incidence or severity in AP.

METHODS

We conducted a hospital-based case-control study in a white Portuguese population (133 AP patients and 232 age- and sex-matched healthy controls) to evaluate the role of 15 gene polymorphisms (2 deletions and 13 single nucleotide polymorphisms [SNPs]) in oxidative stress (GSTM1, GSTT1, GSTP1) and apoptosis genes (CASP7, CASP8, CASP9, CASP10, LTA, TNFRSF1B, TP53) in AP. Criteria for AP were abdominal pain, hyperamylasemia, and contrast-enhanced computed tomography.

RESULTS

The presence of GSTM1 is associated with increased susceptibility for AP, and the GSTP1 Val105Ile SNP is associated with an increased risk for AP in men. CASP9 Phe136Leu/Phe136Phe SNPs (heterozygotes) increases the risk for mild AP (odds ratio, 3.616; 95% confidence interval, 1.151-11.364; P < 0.05), whereas the homozygotic genotype of CASP9 Ala28Val decreases risk for mild AP (odds ratio, 0.296; 95% confidence interval, 0.091-0.963; P < 0.05).

CONCLUSIONS

Our results suggest that variations in GSTM1, GSTP1, and CASP9 may influence risk for AP.

Screening of CPA1 gene mutations in a Chinese Han population with chronic pancreatitis

AIM

To screen the mutations in the carboxypeptidase A1 (CPA1) gene in a Han Chinese population and explore the molecular mechanism behind the pathogenesis of chronic pancreatitis (CP).

METHODS

A total of 146 CP patients treated at Sichuan Provincial People's Hospital and its Chongzhou Branch between October 2014 and April 2016 were included in a case group in this study. Another 200 healthy subjects were selected as a control group. The sequences of the coding region of the CPA1 gene were analyzed using PCR and DNA sequencing and compared with the normal sequence of the CPA1 gene.

RESULTS

In the exon 3 of the CPA1 gene, c.281A>G heterozygous missense mutation and c.370A>G heterozygous missense mutation were detected in one patient each. c.1074C>T heterozygous synonymous mutation in exon 8 was detected in two patients. The c.281A > G, c.370A>G and c.1074C>T mutations were not detected in normal controls. One single nucleotide polymorphism (SNP; rs1126899) was detected in the exon 3 of the CPA1 gene. The distribution of rs1126899 genotype was statistically significant between the CP group and control group. The percentage of CP patients carrying G allele of rs1126899 polymorphism was significantly higher than that of normal controls (74.0% vs 63.0%, χ² = 4.641, P = 0.031). The frequency of G allele of rs1126899 was higher in CP patients than in normal controls (49.0% vs 39.2%, χ² = 6.479, P = 0.011). There were statistically significant differences in the distribution of CC genotype and GG + CG genotype between CP patients and normal controls without alcohol consumption (OR = 1.779, 95%CI: 1.026-3.087, P = 0.039).

CONCLUSION

Novel mutations, c.281A>G, c.370A>G and c.1074C>T of the CPA1 gene, may contribute to the development of CP. The rs1126899 C/G polymorphism of the CPA1 gene is associated with a higher risk for CP in the Chinese Han population.

Genophenotypic Analysis of Pediatric Patients With Acute Recurrent and Chronic Pancreatitis

OBJECTIVES

The aim of this study was to determine if comprehensive genetic testing was useful to identify genetic variants that discriminate chronic pancreatitis (CP) from acute recurrent pancreatitis (ARP) in a pediatric population.

METHODS

We conducted a retrospective review of 50 patients enrolled in our institutional pancreatitis registry between April 2013 and January 2015. Genetic analysis of PRSS1, CFTR, SPINK1, and CTRC classified variants as mutations or variants of unknown clinical significance and the minor allele frequency of variants in our cohort was obtained.

RESULTS

Genetic testing was obtained in 16/16 (100%) of CP and 29/34 (85%) of ARP patients. A total of 39 genetic variants were found in 27 (60%) of 45 subjects tested with 5 (11%) subjects having 2 different genes affected. Variant frequency was greatest in patients for CFTR (17/45, 38%) followed by SPINK1 (11/44, 25%), CTRC (2/27, 7%), and PRSS1 (2/44, 4%). CFTR variants were more likely in those with CP compared to ARP (63% and 24%, P = 0.01).

CONCLUSIONS

This study is the first to find a higher rate of CFTR mutations in CP versus ARP groups using comprehensive genetic testing in a pediatric population.

Hereditary pancreatitis: current perspectives

Hereditary pancreatitis (HP) is a rare cause of acute, recurrent acute, and chronic pancreatitis. It may present similarly to other causes of acute and chronic pancreatitis, and often there has been a protracted evaluation prior to the diagnosis of HP. Since it was first described in 1952, multiple genetic defects that affect the action of digestive enzymes in the pancreas have been implicated. The most common mutations involve the PRSS1, CFTR, SPINK1, and CTRC genes. New mutations in these genes and previously unrecognized mutations in other genes are being discovered due to the increasing use of next-generation genomic sequencing. While the inheritance pathways of these genetic mutations may be variable and complex, sometimes involving coinheritance of other mutations, the clinical presentation of patients tends to be similar. Interactions with environmental triggers often play a role. Patients tend to present at an early age (prior to the second decade of life) and have a significantly increased risk for the development of pancreatic adenocarcinoma. Patients with HP may develop sequelae of chronic pancreatitis such as strictures and fluid collections as well as exocrine and endocrine insufficiency. Management of patients with HP involves avoidance of environmental triggers, surveillance for pancreatic adenocarcinoma, medical therapy for endocrine and exocrine insufficiency, pain management, and endoscopic or surgical treatment for complications. Care for affected patients should be individualized, with an emphasis on early diagnosis and multidisciplinary involvement to develop a comprehensive treatment strategy.

Epithelial Anion Transport as Modulator of Chemokine Signaling

The pivotal role of epithelial cells is to secrete and absorb ions and water in order to allow the formation of a luminal fluid compartment that is fundamental for the epithelial function as a barrier against environmental factors. Importantly, epithelial cells also take part in the innate immune system. As a first line of defense they detect pathogens and react by secreting and responding to chemokines and cytokines, thus aggravating immune responses or resolving inflammatory states. Loss of epithelial anion transport is well documented in a variety of diseases including cystic fibrosis, chronic obstructive pulmonary disease, asthma, pancreatitis, and cholestatic liver disease. Here we review the effect of aberrant anion secretion with focus on the release of inflammatory mediators by epithelial cells and discuss putative mechanisms linking these transport defects to the augmented epithelial release of chemokines and cytokines. These mechanisms may contribute to the excessive and persistent inflammation in many respiratory and gastrointestinal diseases.

Calcium signalling in salivary gland physiology and dysfunction

Studies over the past four decades have established that Ca(2+) is a critical factor in control of salivary gland function and have led to identification of the critical components of this process. The major ion transport mechanisms and ion channels that are involved in fluid secretion have also been established. The key event in activation of fluid secretion is an increase in [Ca(2+) ]i triggered by inositol 1,4,5-trisphosphate (IP3 )-induced release of Ca(2+) from ER via the IP3 receptor (IP3 R). IP3 Rs determine the site of initiation and the pattern of the [Ca(2+) ]i signal in the cell. However, Ca(2+) entry into the cell is required to sustain the elevation of [Ca(2+) ]i and fluid secretion and is mediated by the store-operated Ca(2+) entry (SOCE) mechanism. Orai1, TRPC1, TRPC3 and STIM1 have been identified as critical components of SOCE in these cells. Cells finely tune the generation and amplification of [Ca(2+) ]i signals for regulation of cell function. An important emerging area is the concept that unregulated [Ca(2+) ]i signals in cells can directly cause cell damage, dysfunction and disease. Alternatively, aberrant [Ca(2+) ]i signals can also amplify and increase the rates of cell damage. Such defects in Ca(2+) signalling have been described in salivary glands in conjunction with radiation-induced loss of salivary gland function as well as in the salivary defects associated with the autoimmune exocrinopathy Sjögren's syndrome. Such defects have been associated with altered function or expression of key Ca(2+) signalling components, such as STIM proteins and TRP channels. These studies offer new avenues for examining the mechanisms underlying the disease and development of novel clinical targets and therapeutic strategies.

Clinical Genetic Testing in Gastroenterology

Rapid advances in genetics have led to an increased understanding of the genetic determinants of human disease, including many gastrointestinal (GI) disorders. Coupled with a proliferation of genetic testing services, this has resulted in a clinical landscape where commercially available genetic tests for GI disorders are now widely available. In this review, we discuss the current status of clinical genetic testing for GI illnesses, review the available testing options, and briefly discuss indications for and practical aspects of such testing. Our goal is to familiarize the practicing gastroenterologist with this rapidly changing and important aspect of clinical care.

Association of claudin2 and PRSS1-PRSS2 polymorphisms with idiopathic recurrent acute and chronic pancreatitis: A case-control study from India

BACKGROUND

Gene polymorphisms, including those recently described in the claudin2 gene, have been implicated in recurrent acute (RAP) and chronic pancreatitis (CP). In India, RAP and CP have been associated with SPINK1 polymorphism. In this study, we evaluated the association of claudin2 and PRSS1-PRSS2 polymorphisms with idiopathic RAP and CP.

METHODS

We included 101 prospectively followed patients with documented idiopathic RAP (IRAP) and 96 patients who presented with idiopathic chronic pancreatitis (ICP) without previous history of AP. Controls were 156 unrelated individuals undergoing master health check or with non-specific symptoms. All the samples were genotyped for the SNPs rs7057398 in the claudin2 (CLDN2) gene and rs10273639 in the PRSS1 gene on Realtime polymerase chain reaction platform. Clinical data pertaining to patient and disease characteristics were recorded.

RESULTS

Claudin2 and PRSS1 polymorphisms were seen in a significantly higher proportion of female patients (P = 0.01 and 0.039, respectively). Thirty-three (32.7%) patients with IRAP developed features of early CP during follow-up (mean [95% confidence interval, CI] duration of 11.3 [8.9-13.7] months). Female patients with claudin2 (rs7057398) CC genotype were at significantly higher risk for IRAP (odds ratio [OR] [95% CI] 6.75 [1.82-23.67]; P = 0.004) and progression from IRAP to CP (OR [95% CI] 7.05 [1.51-33.01]; P = 0.007). CT genotype of PRSS1 (rs10273639) was associated IRAP (OR [95% CI] 2.59 [1.1-6.13]; P = 0.030), and both CT and CC genotypes with ICP in women (OR [95% CI] 2.86 [1.12-7.31]; P = 0.033 and 3.73 [1.03-13.59]; P = 0.048, respectively).

CONCLUSION

In this study, we have demonstrated the association of claudin2 (rs7057398) polymorphism with IRAP and progression of IRAP to CP, and PRSS1 (rs10273639) polymorphism with IRAP and ICP.

ESPGHAN and NASPGHAN Report on the Assessment of Exocrine Pancreatic Function and Pancreatitis in Children

The purpose of this clinical report is to discuss several recent advances in assessing exocrine pancreatic insufficiency (EPI) and pancreatitis in children, to review the array of pancreatic function tests, to provide an update on the inherited causes of EPI, with special emphasis on newly available genetic testing, and to review newer methods for evaluating pancreatitis.

Prospective evaluation of the aetiological profile of acute pancreatitis in young adult patients

BACKGROUND

The aetiologies of acute pancreatitis in young adult patients are poorly known.

AIMS

To prospectively evaluate the causes of acute pancreatitis in patients aged less than 35 years.

METHODS

Overall, 309 consecutive patients admitted to our centre for acute pancreatitis received first-line investigations, including medical history, standard laboratory tests, abdominal ultrasound and computed tomography. If no aetiology was found, second-line investigations were performed, including endoscopic ultrasound, magnetic-resonance cholangiopancreatography and genetic testing in cases of idiopathic pancreatitis.

RESULTS

Overall, 66 patients aged between 16 and 35 years were included. After first-line investigations, 49% of cases of acute pancreatitis remained idiopathic. Second-line investigations reduced this rate to 21%. The frequency of aetiologies for acute pancreatitis significantly differed in adults aged ≤ 35 compared to those aged >35 years: biliary aetiology was less frequent (23% versus 43%, p=0.003) as well as alcohol-related (8% versus 24%, p=0.01); drug-induced was more common (16% versus 4%, p=0.0007), as well as cannabis-related (13% versus 1%, p<0.0001), or genetic (10% versus 1.5%, p=0.003).

CONCLUSIONS

The aetiologies of acute pancreatitis significantly differed in adults aged less than 35 years when compared to older patients. Thus, use of medications, exposure to cannabis, and genetic mutations should be actively sought in these patients.

Genetic mutations in SPINK1, CFTR, CTRC genes in acute pancreatitis

Background

Explanation of the ultimate causes of acute and chronic pancreatitis is challenging. Hence, it is necessary to seek various etiological factors, including genetic mutations that may be of importance in triggering recurrence and progression of acute to chronic pancreatitis. The aim of this study was to determine the frequency of genetic mutations in patients with acute pancreatitis and to investigate their relationship with the etiology and clinical course.

Methods

The study included 221 patients treated for acute pancreatitis and 345 healthy subjects as a control group. Peripheral blood samples were collected from each study participant and genomic DNA was isolated. Genotyping of common mutations in the SPINK1 (p.N34S and p.P55S) and CTRC (p.I259V, p.V235I, p.K247_R254del, p.E225A) genes was performed using the high-resolution melting method. Mutations in the CFTR p.F508del (delF508_CTT) were genotyped using allele-specific amplification polymerase chain reaction. All detected mutations were confirmed with direct capillary DNA sequencing.

Results

Mutations in SPINK 1, CFTR and CTRC were detected in 6.3 %, 2.3 % and 1.8 % of patients with acute pancreatitis versus 3.2 %, 3.8 % and 1.2 % of volunteers in the control group. No relationship was found between the detected mutations and severity of acute pancreatitis: mild acute pancreatitis, mutation of CFTR in 4 (2.8 %) and CTRC in 2 (1.4 %) patients; severe acute pancreatitis, mutation of CFTR and CTRC in 1 (2.6 %) case each. The SPINK1 mutation was significantly more frequent in 8 (10.4 %) severe cases than in 6 (4.2 %) mild cases (P < 0.05), and was observed in 5/70 (7.1 %) patients with alcohol-related AP, 5/81 (6.2 %) with biliary AP, and 4/63 (6.3 %) in those without any established cause of the disease.

Conclusions

Mutation p.N34S in SPINK1 may predispose patients to acute pancreatitis, especially in those abusing alcohol, and may promote a more severe course of the disease.