Comprehensive screening for PRSS1, SPINK1, CFTR, CTRC and CLDN2 gene mutations in Chinese paediatric patients with idiopathic chronic pancreatitis: a cohort study

Surgical and Endoscopic Intervention for Chronic Pancreatitis in Children: The Kings College Hospital Experience

Paediatric chronic pancreatitis (CP) is a rare and debilitating pathology that often requires invasive diagnostics and therapeutic interventions either to address a primary cause such as a pancreaticobiliary malunion or to deal with secondary complications such as chronic pain. Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) are two endoscopic modalities that have an established diagnostic role in paediatric CP, and their therapeutic utilisation is increasing in popularity. Surgical decompression of the obstructed and dilated pancreatic duct plays a role in alleviating pancreatic duct hypertension, a common association in CP. Surgery equally has a role in certain anatomical abnormalities of the pancreaticobiliary draining system, or occasionally in some CP complications such as drainage of a symptomatic pancreatic pseudocyst.

Genetic Investigations in Turkish Idiopathic Pancreatitis Patients Show Unique Characteristics

BACKGROUND/AIMS

Pancreatitis is one of the leading causes of digestive system-related hospital admissions, and it has a genetic background in a considerable portion of the patients. In this study, we aimed to investigate the genetic risk factors of idiopathic pancreatitis in Turkish patients and the contribution of copy number variations to the pathogenesis.

MATERIALS AND METHODS

Idiopathic pancreatitis is defined as failure to detect risk factors despite comprehensive clinical assessments. Next-generation sequencing and multiple ligand-dependent probe amplification of PRSS1, SPINK1, CTRC, and CFTR were performed. For further genotype-phenotype correlations, patients were also questioned for the age of onset, family history, and pancreatic divisum.

RESULTS

A total of 68 idiopathic pancreatitis cases were enrolled. Variants with potential clinical significance of PRSS1 were identified in 13.4%, SPINK1 in 6.3%, CTRC in 4.7%, and CFTR in 26.5% of the patients. No copy number variants were seen in any of these genes. At least 7.4% of the participants had complex genetic etiology involving 2 genes.

CONCLUSIONS

At least 42.6% of the participants had a potential genetic risk factor. Five novel genetic variants were identified, and distinctive genetic risk factors of Turkish population were shown. The results showed that genetic etiology was frequent in pancreatitis and it was even more prominent in patients with early-onset disease. Considering that genetic risk factors may be informative for decisionmaking in the treatment options in addition to providing extensive prognostic value and familial genetic consultation; clinicians need to be more eager to offer genetic tests to pancreatitis patients.

Analysis of INSPPIRE-2 Cohort: Risk Factors and Disease Burden in Children With Acute Recurrent or Chronic Pancreatitis

OBJECTIVES

The objective of this study is to investigate risk factors and disease burden in pediatric acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP).

METHODS

Data were obtained from INternational Study group of Pediatric Pancreatitis: In search for a cuRE-2 (INSPPIRE-2), the largest multi-center prospective cohort study in pediatric patients with ARP or CP.

RESULTS

Of 689 children, 365 had ARP (53%), 324 had CP (47%). CP was more commonly associated with female sex, younger age at first acute pancreatitis (AP) attack, Asian race, family history of CP, lower BMI%, genetic and obstructive factors, PRSS1 mutations and pancreas divisum. CFTR mutations, toxic-metabolic factors, medication use, hypertriglyceridemia, Crohn disease were more common in children with ARP. Constant or frequent abdominal pain, emergency room (ER) visits, hospitalizations, medical, endoscopic or surgical therapies were significantly more common in CP, episodic pain in ARP. A total of 33.1% of children with CP had exocrine pancreatic insufficiency (EPI), 8.7% had diabetes mellitus. Compared to boys, girls were more likely to report pain impacting socialization and school, medical therapies, cholecystectomy, but no increased opioid use. There was no difference in race, ethnicity, age at first AP episode, age at CP diagnosis, duration of disease, risk factors, prevalence of EPI or diabetes between boys and girls. Multivariate analysis revealed that family history of CP, constant pain, obstructive risk factors were predictors of CP.

CONCLUSIONS

Children with family history of CP, constant pain, or obstructive risk factors should raise suspicion for CP.

Personalized medicine approaches in cystic fibrosis related pancreatitis

We report a rare case of a patient with cystic fibrosis suffering from debilitating abdominal pain due to chronic pancreatitis. This 13-year-old patient was evaluated for surgical intervention to relieve pain from chronic pancreatitis and to improve quality of life. The patient carried two mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene; the most common ΔF508 variant and a second variant, p.Glu1044Gly, which has not been previously described. The patient's condition did not improve despite medical management and multiple endoscopic interventions, and therefore total pancreatectomy with islet autotransplantation and a near-total duodenectomy was offered for definitive management. Patient-derived duodenal crypts were isolated and cultured from the resected duodenum, and duodenal organoids were generated to test CFTR function. Our studies demonstrate that this novel mutation (ΔF508/p.Glu1044Gly) caused severely impaired CFTR function in vitro. The Food and Drug Administration (FDA)-approved drug ivacaftor, a CFTR potentiator, was identified to robustly improve CFTR function in the context of this novel mutation. Herein, we describe a personalized medicine approach consisting of performing drug testing on individual patient derived organoids that has potential to guide management of patients with novel CFTR genetic mutations. Identified effective medical therapeutics using this approach may avoid irreversible surgical treatments such as total pancreatectomy with islet autotransplantation in the future.

WITHDRAWN: Clinical interpretation of PRSS1 gene variants in patients with pancreatitis

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Clinics and Research in Hepatology and Gastroenterology, Volume 45, Issue 1, 2021, 101497. https://doi.org/10.1016/j.clinre.2020.07.004. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal

No Stone Left Unturned: Pediatric Pancreatic Stones Presenting With Obstructive Jaundice

Pancreatic lithiasis, the formation of calcifications in the pancreatic duct, occurs uncommonly in pediatric patients but can occur more frequently with chronic pancreatitis (CP). Cystic fibrosis (CF) is one of the major causes of pancreatic lithiasis in pediatric patients, with mutations in the CF transmembrane conductance regulator (CFTR) gene reported in up to 23% of pediatric CP patients. Mutations in the CFTR gene can lead to mild cases of CF, which may delay diagnosis and treatment. In such cases, pancreatitis can be the presenting symptom in children with CF. We report a unique case of a 10-year-old female with previously undiagnosed and untreated CF presenting with abdominal pain, vomiting, and obstructive jaundice. Her pancreatic lithiasis and biliary obstruction were successfully treated with endoscopic retrograde cholangiopancreatography (ERCP).

Trypsinogen (PRSS1 and PRSS2) gene dosage correlates with pancreatitis risk across genetic and transgenic studies: a systematic review and re-analysis

Trypsinogen (PRSS1, PRSS2) copy number gains and regulatory variants have both been proposed to elevate pancreatitis risk through a gene dosage effect (i.e., by increasing the expression of wild-type protein). However, to date, their impact on pancreatitis risk has not been thoroughly evaluated whilst the underlying pathogenic mechanisms remain to be explicitly investigated in mouse models. Genetic studies of the rare trypsinogen duplication and triplication copy number variants (CNVs), and the common rs10273639C variant, were collated from PubMed and/or ClinVar. Mouse studies that analyzed the influence of a transgenically expressed wild-type human PRSS1 or PRSS2 gene on the development of pancreatitis were identified from PubMed. The genetic effects of the different risk genotypes, in terms of odds ratios, were calculated wherever appropriate. The genetic effects of the rare trypsinogen duplication and triplication CNVs were also evaluated by reference to their associated disease subtypes. We demonstrate a positive correlation between increased trypsinogen gene dosage and pancreatitis risk in the context of the rare duplication and triplication CNVs, and between the level of trypsinogen expression and disease risk in the context of the heterozygous and homozygous rs10273639C-tagged genotypes. We retrospectively identify three mouse transgenic studies that are informative in relation to the pathogenic mechanism underlying the trypsinogen gene dosage effect in pancreatitis. Trypsinogen gene dosage correlates with pancreatitis risk across genetic and transgenic studies, highlighting the fundamental role of dysregulated expression of wild-type trypsinogen in the etiology of pancreatitis. Specifically downregulating trypsinogen expression in the pancreas may serve as a potential therapeutic and/or prevention strategy for pancreatitis.

Pancreatic Associated Manifestations in Pediatric Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBDs) are chronic relapsing inflammatory conditions of the gastrointestinal tract, encompassing Crohn’s disease (CD), ulcerative colitis (UC) and inflammatory bowel disease unclassified (IBD-U). They are currently considered as systemic disorders determined by a set of genetic predispositions, individual susceptibility and environmental triggers, potentially able to involve other organs and systems than the gastrointestinal tract. A large number of patients experiences one or more extraintestinal manifestations (EIMs), whose sites affected are mostly represented by the joints, skin, bones, liver, eyes, and pancreas. Pancreatic abnormalities are not uncommon and are often underestimated, encompassing acute and chronic pancreatitis, autoimmune pancreatitis, exocrine pancreatic insufficiency and asymptomatic elevation of pancreatic enzymes. In most cases they are the result of environmental triggers. However, several genetic polymorphisms may play a role as precipitating factors or contributing to a more severe course. The aim of this paper is to provide an updated overview on the available evidence concerning the etiology, pathogenesis and clinical presentation of pancreatic diseases in IBD pediatric patients.

Disordered Gut Microbiota in Children Who Have Chronic Pancreatitis and Different Functional Gene Mutations

Chronic pancreatitis (CP) is a serious condition whose pathogenic mechanism is unclear. Interactions of host genetic factors with gut microbiota have a role, but little is known, especially in children with CP (CCP), in which the external factors are less important. Our objective was to identify the main gut microbiota genera in CCP and to characterize the functional mutations of these patients.

Clinical Outcomes Following Therapeutic Endoscopic Retrograde Cholangiopancreatography in Children With Pancreas Divisum

OBJECTIVES

Pancreas divisum (PD) is a risk factor in children for the development of acute pancreatitis. Endoscopic retrograde cholangiopancreatography (ERCP) with minor papilla endoscopic sphincterotomy (mPES) may be of clinical benefit, however, the clinical outcomes from endotherapy remain unclear. We sought to review the outcomes and safety of therapeutic ERCP in children with PD.

METHODS

We performed a retrospective chart of children with PD who underwent an ERCP between February 2012 and December 2018. Pertinent patient, clinical and procedure information was collected including procedure-related adverse events. A follow-up questionnaire of the parent was conducted to determine the clinical impact from endotherapy.

RESULTS

Fifty-eight ERCPs were performed in 27 patients (14 boys; mean age: 9.7 years, range 2-19) with PD. All patients underwent a successful mPES. A genetic variant was identified in 19/26 (73%) tested patients. Post-ERCP pancreatitis (PEP) was the only observed adverse event; 21% (12/58). Median follow-up interval from first ERCP intervention to questionnaire completion was 31.5 months (range: 4--72 months). Of the 20 questionnaire responders, 13 reported clinical improvement from endotherapy.

CONCLUSIONS

The majority of children from our PD cohort possessed at least 1 genetic variant. Most questionnaire responders had a favorable response to endotherapy. PEP rate was comparable with that of prior reports in adult patients.

Clinical interpretation of PRSS1 variants in patients with pancreatitis

Since the description of the PRSS1 gene encoding the cationic trypsinogen as being involved in dominant hereditary pancreatitis, more than 50 PRSS1 variants have been reported. Among the PRSS1 variants that have been classified as pathogenic, some have a high penetrance and others have a low penetrance. Assessing the clinical relevance of PRSS1 variants is often complicated in the absence of functional evidence and interpretation of rare variants is not very easy in clinical practice. The aim of this study was to review the different variants identified in the PRSS1 gene and to classify them according to their degree of deleterious effect. This classification was based on the results of several in vitro experiments and on population data, in comparing the allelic frequency of each variant in patients with pancreatitis and in unaffected individuals. This review should help geneticists and clinicians in charge of patient's care and genetic counseling to interpret molecular results.

Clinical interpretation of SPINK1 and CTRC variants in pancreatitis

Since the description of the SPINK1 gene encoding the serine protease inhibitor Kazal type 1 and the CTRC gene encoding the Chymotrypsin C as being involved in chronic pancreatitis, more than 56 SPINK1 and 87 CTRC variants have been reported. Assessing the clinical relevance of SPINK1 and CTRC variants is often complicated in the absence of functional evidence and interpretation of rare variants is not very easy in clinical practice. The aim of this study was to review the different variants identified in these two genes and to classify them according to their degree of damaging effect. This classification was based on the results of in vitro experiments, in silico analysis using different prediction tools, and on population data, in comparing the allelic frequency of each variant in patients with pancreatitis and in unaffected control individuals. This review should help geneticists and clinicians in charge of patient's care and genetic counseling to interpret the results of genetic studies.

IVS8-5T Allele of CFTR is the Risk Factor in Chronic Pancreatitis, Especially in Idiopathic Chronic Pancreatitis

BACKGROUND

Cystic fibrosis transmembrane conductance regulator IVS8-5T gene variation appears to be associated with a higher risk of chronic pancreatitis (CP); however, there is inconsistency between previous reported studies. Here, we performed a meta-analysis to investigate this relationship.

MATERIALS AND METHODS

PubMed and WANFANG databases were searched for the case-control studies that contained Patients with CP with IVS8-5T variation. Odd ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relevance of IVS8-5T gene variation and CP.

RESULTS

Analysis showed that the frequency of the 5T allele was significantly higher in CP subjects than that in control subjects (OR = 1.43, 95% CI: 1.13-1.81, I² = 1.2%). Based on the subgroup analysis stratified by etiology, the 5T allele was associated with a higher risk of idiopathic chronic pancreatitis (ICP) (OR = 1.80, 95% CI: 1.18-2.76, I² = 0.0%) and not alcoholic CP (OR = 2.14, 95% CI: 0.98-4.66, I² = 0.0%). Further study indicated that the 5T allele was related to higher ICP prevalence in the European population (OR = 1.79, 95% CI: 1.06-3.03, I² = 0.0%). In contrast, there was no significant difference between ICP subjects and healthy controls within the Asian population (OR = 1.84, 95% CI: 0.91-3.72, I² = 38.0%).

CONCLUSIONS

Cystic fibrosis transmembrane conductance regulator IVS8-5T is a risk factor in patients with CP. IVS8-5T variation may play a significant role in the occurrence of ICP, especially in the European population.

Genetic variants in acute, acute recurrent and chronic pancreatitis affect the progression of disease in children

BACKGROUND/OBJECTIVES

Acute pancreatitis (AP) is emerging in pediatrics. A subset of children with AP progresses to acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP). The role of extensive gene testing in the progression has not been investigated previously. We have followed children enrolled in the registry and at our center for progression to ARP and CP after the first attack.

METHODS

This study utilizes an extensive gene sequencing panel as a platform to evaluate the role of genetics in first attack AP, and the progression over time, from first attack to ARP and CP in children.

RESULTS

Genes, with corresponding variants were involved in the 3 groups studied: AP, ARP and CP. We have shown that the presence of gene variants from the eight tested genes is enriched in the CP group compared to the AP and ARP groups. The presence of more than one gene was associated with CP (p = 0.01). SPINK1 mutation(s) was significantly associated with faster progression to ARP, (p = 0.04). Having a variant from CFTR, SPINK1 or PRSS1, was associated with the faster progression from AP to CP over time (p < 0.05).

CONCLUSIONS

This study shows that genetics have a significant role in progression to ARP and CP from the first attack of pancreatitis.

Risk factors and prediction score for chronic pancreatitis: A nationwide population-based cohort study

AIM

To explore the risk factors of developing chronic pancreatitis (CP) in patients with acute pancreatitis (AP) and develop a prediction score for CP.

METHODS

Using the National Health Insurance Research Database in Taiwan, we obtained large, population-based data of 5971 eligible patients diagnosed with AP from 2000 to 2013. After excluding patients with obstructive pancreatitis and biliary pancreatitis and those with a follow-up period of less than 1 year, we conducted a multivariate analysis using the data of 3739 patients to identify the risk factors of CP and subsequently develop a scoring system that could predict the development of CP in patients with AP. In addition, we validated the scoring system using a validation cohort.

RESULTS

Among the study subjects, 142 patients (12.98%) developed CP among patients with RAP. On the other hand, only 32 patients (1.21%) developed CP among patients with only one episode of AP. The multivariate analysis revealed that the presence of recurrent AP (RAP), alcoholism, smoking habit, and age of onset of < 55 years were the four important risk factors for CP. We developed a scoring system (risk score 1 and risk score 2) from the derivation cohort by classifying the patients into low-risk, moderate-risk, and high-risk categories based on similar magnitudes of hazard and validated the performance using another validation cohort. Using the prediction score model, the area under the curve (AUC) [95% confidence interval (CI)] in predicting the 5-year CP incidence in risk score 1 (without the number of AP episodes) was 0.83 (0.79, 0.87), whereas the AUC (95%CI) in risk score 2 (including the number of AP episodes) was 0.84 (0.80, 0.88). This result demonstrated that the risk score 2 has somewhat better prediction performance than risk score 1. However, both of them had similar performance between the derivation and validation cohorts.

CONCLUSION

In the study,we identified the risk factors of CP and developed a prediction score model for CP.

Pediatric chronic pancreatitis: Updates in the 21st century

Pediatric Pancreatitis has gained a lot of attention in the last decade. Updates in medical management include new testing technologies in genetics, function testing and imaging modalities. Updates in surgical management have taken place as well, with total pancreatectomy islet auto transplantation reserved for a specific patient population that meets the clinical criteria. Multidisciplinary team management is needed for patients with chronic pancreatitis to ensure optimal outcomes.

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.

Clinical profile and treatment outcome of chronic pancreatitis in children: a long-term follow-up study of 156 cases

AIM

There is a paucity of literature in pediatric chronic pancreatitis (CP) and most information is derived from adult literature. We, therefore, analyzed our experience of CP to look for clinical profile and long-term outcome.

METHODS

From January 2003 to December 2015, 156 consecutive children (≤18 years) diagnosed as CP were included. Their clinical profile, management, and follow-up data were retrieved. Genetic markers (PRSS1, SPINK1, and CFTR) were studied in 40 idiopathic cases.

RESULTS

The median age of the patients was 13 [inter-quartile range (IQR): 10-14] years (93 males) and 134 (86%) were idiopathic. Genetic mutations were found in 22/40 (55%) idiopathic cases. All but two presented with pain abdomen (episodic pain in 93.6%) and symptom duration was 12 (IQR: 6-24) months. There were two subsets; calcific (CCP) 68 (43.5%) and non-calcific (NCCP) 88 (56.5%). In CCP group, significantly more children had Cambridge grade 5 magnetic resonance cholangiopancreatography changes, low weight Z-score, and had continuous pain more compared to NCCP group. Over a median follow-up of 23 (IQR: 8-45.5) months, more children in CCP group had complications. Endoscopic therapy (done for persistent pain in 40) relieved pain in 52.5% of cases while medical therapy did so in 36% of cases.

CONCLUSION

Pediatric CP in Asia presents with episodic pain and genetic predisposition seems to be a major cause. There are two subsets; CCP and NCCP with former showing marked imaging changes, more often associated with malnutrition and complications. Endoscopic therapy for pain relief gives modest benefit but medical therapy is not encouraging.

Association between F508 deletion in CFTR and chronic pancreatitis risk

BACKGROUND

The cystic fibrosis transmembrane conductance regulator (CFTR) has been reported to influence individual susceptibility to chronic pancreatitis (CP), but the results of previous studies are controversial.

AIMS

We performed a study to demonstrate the relationship between CFTR and CP.

METHODS

We searched PubMed, Scopus, and Embase for studies of patients with CP. Seven studies from 1995 to 2016 were identified, and included 64,832 patients. Pooled prevalence and 95% confidence intervals (CIs) were calculated.

RESULTS

F508 deletion in CFTR was significantly positively associated with CP risk in the overall analysis (odds ratio [OR]=3.20, 95% CI: 2.30-4.44, I²=31.7%). In subgroup analysis stratified by ethnicity, F508 deletion was significantly associated with CP risk in Indian populations, using a fixed effects model (ORs=5.45, 95% CI: 2.52-11.79, I²=0.0%), and in non-Indian populations, using a random effects model (ORs=3.59, 95% CI: 1.73-7.48, I²=60.9%). At the same time, we found that Indians with F508 deletion had much higher CP prevalence than non-Indians. Interestingly, F508 deletion was also associated with CP and idiopathic CP risk in subgroup analysis stratified by aeitiology, using the fixed effects model.

CONCLUSIONS

Based on current evidence, F508 deletion is a risk factor for CP, and Indians with F508 deletion have much higher CP morbidity.

The clinical characteristics of patients with mitochondrial tRNA Leu(UUR)m.3243A > G mutation: Compared with type 1 diabetes and early onset type 2 diabetes

OBJECTIVE

This study presents nine patients with mitochondrial tRNA Leu (UUR) m.3243A>G mutation and compares the clinical characteristics and diabetes complications with type 1 diabetes (T1DM) or early onset type 2 diabetes (T2DM).

METHODS

The study covers 9 patients with MIDD, 33 patients with T1DM and 86 patients (age of onset ≤35years) with early onset T2DM, matched for sex, age at onset of diabetes, duration of diabetes. All patients with MIDD were confirmed as carrying the m.3243A>G mitochondrial DNA mutation. Serum HbA1c, beta-cell function, retinal and renal complications of diabetes, bone metabolic markers, lumbar spine and femoral neck BMD bone mineral density were compared to characterize the clinical features of all patients.

RESULTS

Nine patients were from five unrelated families, and the mean (SD) onset age of those patients was 31.2±7.2year. Two patients required insulin at presentation, and six patients progressed to insulin requirement after a mean of 7.2years. β-Cell function in the MIDD group was intermediate between T1DM and early-onset T2DM. In MIDD, four patients were diagnosed as diabetic retinopathy (4/9) and five patients (5/9) had macroalbuminuria. The number of patients with diabetic retinopathy and macroalbuminuria in the MIDD group was comparable to T1DM or early-onset T2DM. The rate of osteoporosis (BMD T-score<-2.5 SD) in the patient with MIDD was higher than the T1DM or early-onset T2DM group.

CONCLUSION

Our study indicates that of the nine subjects with MIDD, three patients (1-II-1, 1-II-3, 1-II-4) who came from the same family had a history of acute pancreatitis. Compared with T1DM or early-onset T2DM matched for sex, age, duration of diabetes, MIDD patients had the highest rate of osteoporosis.

PRSS1, SPINK1, CFTR, and CTRC Pathogenic Variants in Korean Patients With Idiopathic Pancreatitis

BACKGROUND

This study aimed to identify pathogenic variants of PRSS1, SPINK1, CFTR, and CTRC genes in Korean patients with idiopathic pancreatitis.

METHODS

The study population consisted of 116 Korean subjects (65 males, 51 females; mean age, 30.4 yr, range, 1-88 yr) diagnosed with idiopathic chronic pancreatitis (ICP), idiopathic recurrent acute pancreatitis (IRAP), or idiopathic acute pancreatitis (IAP). We analyzed sequences of targeted regions in the PRSS1, SPINK1, CFTR, and CTRC genes, copy numbers of PRSS1 and SPINK1, and clinical data from medical records.

RESULTS

We identified three types of pathogenic PRSS1 variants in 11 patients, including p.N29I (n=1), p.R122H (n=1), and p.G208A (n=9). Sixteen patients exhibited heterozygous pathogenic variants of SPINK1, including c.194+2T>C (n=12), p.N34S (n=3), and a novel pathogenic splicing variation c.194+1G>A. A heterozygous CFTR p.Q1352H pathogenic variant was detected in eight patients. One patient carried a heterozygous CTRC p.P249L pathogenic variant, which is a known high-risk variant for pancreatitis. All patients had normal PRSS1 and SPINK1 gene copy numbers. Weight loss occurred more frequently in patients carrying the p.G208A pathogenic variant, while pancreatic duct stones occurred more frequently in patients with the c.194+2T>C pathogenic variant.

CONCLUSIONS

Pathogenic variants of PRSS1, SPINK1, and CFTR were associated with idiopathic pancreatitis, while pathogenic variants of CTRC were not. Copy number variations of PRSS1 and SPINK1 were not detected.

Genetic Risk in Chronic Pancreatitis: The Trypsin-Dependent Pathway

Genetic investigations have provided unique insight into the mechanism of chronic pancreatitis in humans and firmly established that uncontrolled trypsin activity is a central pathogenic factor. Mutations in the PRSS1, SPINK1, and CTRC genes promote increased activation of trypsinogen to trypsin by stimulation of autoactivation or by impairing protective trypsinogen degradation and/or trypsin inhibition. Here we review key genetic and biochemical features of the trypsin-dependent pathological pathway in chronic pancreatitis.

The Etiology and Clinical Course of Chronic Pancreatitis in Children With Early Onset of the Disease

OBJECTIVES

The etiological factors of chronic pancreatitis (CP) in children differ from those in adults. To date, no study has assessed the clinical course of CP in young children. The aim of our study was to evaluate the etiology and the clinical presentation of the disease in children with disease onset before 5 years of age in comparison to later-onset of CP.

METHODS

A total of 276 children with CP, hospitalized from 1988 to 2015, were enrolled in the study. Data on presentation, diagnostic findings, and treatment were reviewed. Two hundred sixty patients were screened for the most frequent mutations in major pancreatitis-associated genes, such as cationic trypsinogen/serine protease gene (PRSS1), serine protease inhibitor, Kazal type 1 gene (SPINK1), and cystic fibrosis transmembrane conductance regulator gene (CFTR).

RESULTS

The disease onset before the age of 5 years occurred in 51 patients (group 1), the later onset in 225 patients (group 2). We found no significant discrepancies in distribution of the etiological factors between groups. The youngest patients (group 1) had more pancreatitis episodes (median 5.0 vs 3.00; P < 0.05) and underwent surgeries more frequently (25.5% vs 8.9%; P < 0.05). It could be associated with significantly longer follow-up in early onset group (median 6 vs 4 years; P < 0.05). There were no differences in nutritional status or exocrine and endocrine pancreatic function.

CONCLUSIONS

Early- and later-onset pancreatitis have similar etiological factors with predominance of gene mutations. The most frequent mutation found was p.Asn34Ser (N34S) in SPINK1 gene. The clinical presentation differed in number of pancreatitis episodes and frequency of surgeries.

Extensive molecular analysis suggested the strong genetic heterogeneity of idiopathic chronic pancreatitis

Rationale: Genetic features of Chronic Pancreatitis (CP) have been extensively investigated mainly testing genes associated to the trypsinogen activation pathway. However, different molecular pathways involving other genes may be implicated in CP pathogenesis. Objectives: 80 patients with Idiopathic CP were investigated using Next Generation Sequencing approach with a panel of 70 genes related to six different pancreatic pathways: premature activation of trypsinogen; modifier genes of Cystic Fibrosis phenotype; pancreatic secretion and ion homeostasis; Calcium signalling and zymogen granules exocytosis; autophagy; autoimmune pancreatitis related genes. Results: We detected mutations in 34 out of 70 genes examined; 64/80 patients (80.0%) were positive for mutations in one or more genes, 16/80 patients (20.0%) had no mutations. Mutations in CFTR were detected in 32/80 patients (40.0%) and 22 of them exhibited at least one mutation in genes of other pancreatic pathways. Of the remaining 48 patients, 13/80 (16.3%) had mutations in genes involved in premature activation of trypsinogen and 19/80 (23.8%) had mutations only in genes of the other pathways: 38/64 patients positive for mutations showed variants in two or more genes (59.3%). Conclusions: Our data, although to be extended with functional analysis of novel mutations, suggest a high rate of genetic heterogeneity in chronic pancreatitis and that trans-heterozygosity may predispose to the idiopathic CP phenotype.

Common Variants in CLDN2 and MORC4 Genes Confer Disease Susceptibility in Patients with Chronic Pancreatitis

A recent genome-wide association study (GWAS) identified association with variants in X-linked CLDN2 and MORC4, and PRSS1-PRSS2 loci with chronic pancreatitis (CP) in North American patients of European ancestry. We selected 9 variants from the reported GWAS and replicated the association with CP in Indian patients by genotyping 1807 unrelated Indians of Indo-European ethnicity, including 519 patients with CP and 1288 controls. The etiology of CP was idiopathic in 83.62% and alcoholic in 16.38% of 519 patients. Our study confirmed a significant association of 2 variants in CLDN2 gene (rs4409525-OR 1.71, P = 1.38 x 10-09; rs12008279-OR 1.56, P = 1.53 x 10-04) and 2 variants in MORC4 gene (rs12688220-OR 1.72, P = 9.20 x 10-09; rs6622126-OR 1.75, P = 4.04x10-05) in Indian patients with CP. We also found significant association at PRSS1-PRSS2 locus (OR 0.60; P = 9.92 x 10-06) and SAMD12-TNFRSF11B (OR 0.49, 95% CI [0.31-0.78], P = 0.0027). A variant in the gene MORC4 (rs12688220) showed significant interaction with alcohol (OR for homozygous and heterozygous risk allele -14.62 and 1.51 respectively, P = 0.0068) suggesting gene-environment interaction. A combined analysis of the genes CLDN2 and MORC4 based on an effective risk allele score revealed a higher percentage of individuals homozygous for the risk allele in CP cases with 5.09 fold enhanced risk in individuals with 7 or more effective risk alleles compared with individuals with 3 or less risk alleles (P = 1.88 x 10-14). Genetic variants in CLDN2 and MORC4 genes were associated with CP in Indian patients.

Energetic etiologies of acute pancreatitis: A report of five cases

There are several common causes of acute pancreatitis, principally excessive alcohol intake and gallstones, and there are many rare causes. However, cases of pancreatitis still occur in the absence of any recognizable factors, and these cases of idiopathic pancreatitis suggest the presence of unrecognized etiologies. Five cases of acute pancreatitis in four patients came to attention due to a strong temporal association with exposure to nerve stimulators and energy drinks. Given that these cases of pancreatitis were otherwise unexplained, and given that these exposures were not clearly known to be associated with pancreatitis, we performed a search for precedent cases and for mechanistic bases. No clear precedent cases were found in PubMed and only scant, weak precedent cases were found in public-health databases. However, there was a coherent body of intriguing literature in support of a mechanistic basis for these exposures playing a role in the etiology of pancreatitis.

Serine Protease Inhibitor Kazal Type 1 (SPINK1) c.194+2T > C Mutation May Predict Long-term Outcome of Endoscopic Treatments in Idiopathic Chronic Pancreatitis

Endoscopic interventional is a commonly used treatment method for idiopathic chronic pancreatitis. Serine protease inhibitor Kazal type 1 (SPINK1) 194+2T>C mutation is most frequently observed in Chinese pancreatitis patients and influences the clinical course of idiopathic chronic pancreatitis patients. We conducted this study to determine the impacts of this mutation on the outcome of endoscopic treatments.In this study, we enrolled 423 patients. Among them, 101 idiopathic chronic pancreatitis patients without other relevant mutations had a successful endoscopic procedure and completed follow-up. Clinical characteristics including Izbicki pain score, exocrine and endocrine function, were evaluated. Genetic sequencing was conducted to detect SPINK1 194+2T>C mutations.The c.194+2T>C mutation was found in 58 (57.43%) patients. Factors relevant to pain relief are c.194+2T>C mutation (P = 0.011), severe pain before treatment (P = 0.005), and necessary subsequent endoscopic treatments (P < 0.001). More patients with the intronic mutation had deteriorated endocrine function (P = 0.001) relative to those patients without the mutation.Patients carrying the c.194+2T>C mutation were less likely to achieve pain relief through endoscopic treatments. They also have a higher risk of endocrine function deterioration. SPINK1 c.194+2T>C mutation may be applied as a pretreatment predictor in idiopathic chronic pancreatitis 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.

Targeted next-generation sequencing effectively analyzed the cystic fibrosis transmembrane conductance regulator gene in pancreatitis

BACKGROUND

The cystic fibrosis transmembrane conductance regulator (CFTR) gene, responsible for the development of cystic fibrosis, is known as a pancreatitis susceptibility gene. Direct DNA sequencing of PCR-amplified CFTR gene segments is a first-line method to detect unknown mutations, but it is a tedious and labor-intensive endeavor given the large size of the gene (27 exons, 1,480 amino acids). Next-generation sequencing (NGS) is becoming standardized, reducing the cost of DNA sequencing, and enabling the generation of millions of reads per run. We here report a comprehensive analysis of CFTR variants in Japanese patients with chronic pancreatitis using NGS coupling with target capture.

METHODS

Exon sequences of the CFTR gene from 193 patients with chronic pancreatitis (121 idiopathic, 46 alcoholic, 17 hereditary, and nine familial) were captured by HaloPlex target enrichment technology, followed by NGS.

RESULTS

The sequencing data covered 91.6 % of the coding regions of the CFTR gene by ≥ 20 reads with a mean read depth of 449. We could identify 12 non-synonymous variants including three novel ones [c.A1231G (p.K411E), c.1753G>T (p.E585X) and c.2869delC (p.L957fs)] and seven synonymous variants including three novel ones in the exonic regions. The frequencies of the c.4056G>C (p.Q1352H) and the c.3468G>T (p.L1156F) variants were higher in patients with chronic pancreatitis than those in controls.

CONCLUSIONS

Target sequence capture combined with NGS is an effective method for the analysis of pancreatitis susceptibility genes.

Framework for interpretation of trypsin-antitrypsin imbalance and genetic heterogeneity in pancreatitis

Early intracellular premature trypsinogen activation was interpreted as the key initiator of pancreatitis. When the balance in the homeostasis of trypsin and antitrypsin system is disequilibrated, elevated aggressive enzymes directly attack the pancreatic tissue, which leads to pancreatic destruction and inflammation. However, trypsin alone is not enough to cause complications in pancreatitis, which may play a crucial role in modulating signaling events in the initial phase of the disease. NFκB activation is the major inflammatory pathway involved in the occurrence and development of pancreatitis and it can be induced by intrapancreatic activation of trypsinogen. Synthesis of trypsinogen occurs in endoplasmic reticulum (ER), and ER stress is an important early acinar cell event. Components of ER stress response are known to be able to trigger cell death as well as NFκB signaling cascade. The strongest evidence supporting the trypsin-centered theory is that gene mutations, which lead to the generation of more trypsin, or reduce the activity of trypsin inhibitors or trypsin degradation, are associated with pancreatitis. Thus, trypsin-antitrypsin imbalance may be the first step leading to pancreatic autodigestion and inducing other pathways. Continued experimental studies are necessary to determine the specific relationships between trypsin-antitrypsin imbalance and genetic heterogeneity in pancreatitis. In this article, we review the latest advances that contributed to the understanding of the basic mechanisms behind the occurrence and development of pancreatitis with a focus on the interpretation of trypsin-antitrypsin imbalance and their relationships with other inflammation pathways. We additionally highlight genetic predispositions to pancreatitis and possible mechanisms associated with them.