alpha-chymotrypsin and Pancreatitis--Chronic

Chymotrypsin C (CTRC) is a digestive serine protease produced by the pancreas that regulates intrapancreatic trypsin activity and provides a defensive mechanism against chronic pancreatitis (CP). CTRC exerts its protective effect by promoting degradation of trypsinogen, the precursor to trypsin. Loss-of-function missense and microdeletion variants of CTRC are found in around 4% of CP cases and increase disease risk by approximately 3-7-fold. In addition, a commonly occurring synonymous CTRC variant c.180C>T (p.Gly60=) was reported to increase CP risk in various cohorts but a global analysis of its impact has been lacking. Here, we analyzed the frequency and effect size of variant c.180C>T in Hungarian and pan-European cohorts, and performed meta-analysis of the new and published genetic association data. When allele frequency was considered, meta-analysis revealed an overall frequency of 14.2% in patients and 8.7% in controls (allelic odds ratio (OR) 2.18, 95% confidence interval (CI) 1.72-2.75). When genotypes were examined, c.180TT homozygosity was observed in 3.9% of CP patients and in 1.2% of controls, and c.180CT heterozygosity was present in 22.9% of CP patients and in 15.5% of controls. Relative to the c.180CC genotype, the genotypic OR values were 5.29 (95% CI 2.63-10.64), and 1.94 (95% CI 1.57-2.38), respectively, indicating stronger CP risk in homozygous carriers. Finally, we obtained preliminary evidence that the variant is associated with reduced CTRC mRNA levels in the pancreas. Taken together, the results indicate that CTRC variant c.180C>T is a clinically relevant risk factor, and should be considered when genetic etiology of CP is investigated.

Topics: Case-Control Studies; Chymotrypsin; Genetic Predisposition to Disease; Humans; Mutation; Pancreatitis, Chronic; Trypsin

The digestive protease chymotrypsin C (CTRC) protects the pancreas against pancreatitis by degrading potentially harmful trypsinogen. Loss-of-function genetic variants in CTRC increase risk for chronic pancreatitis (CP) with variable effect size, as judged by the reported odds ratio (OR) values. Here, we performed a meta-analysis of published studies on four variants that alter the CTRC amino-acid sequence, are clinically relatively common (global carrier frequency in CP >1%), reproducibly showed association with CP and their loss of function phenotype was verified experimentally. We found strong enrichment of CTRC variants p.A73T, p.V235I, p.K247_R254del, and p.R245W in CP cases versus controls, yielding OR values of 6.5 (95% confidence interval (CI) 2.4-17.8), 4.5 (CI 2.2-9.1), 5.4 (CI 2.6-11.0), and 2.6 (CI 1.6-4.2), respectively. Subgroup analysis demonstrated disease association of variants p.K247_R254del and p.R245W in alcoholic CP with similar effect sizes as seen in the overall CP group. Homozygosity or compound heterozygosity were rare and seemed to be associated with higher risk. We also identified a so far unreported linkage disequilibrium between variant p.K247_R254del and the common c.180C>T (p.G60 =) haplotype. Taken together, the results indicate that heterozygous loss-of-function CTRC variants increase the risk for CP approximately 3-7-fold. This meta-analysis confirms the clinical significance of CTRC variants and provides further justification for the genetic screening of CP patients.

Topics: Chymotrypsin; Genetic Predisposition to Disease; Humans; Mutation; Pancreatitis, Alcoholic; Pancreatitis, Chronic

The aim was to review evidence about diabetes secondary to hereditary pancreatitis, seeking novel diagnostic and treatment features.. Hereditary pancreatitis (HP) is an autosomal dominant condition, characterized by recurrent episodes of acute pancreatitis, progression to fibrosis, and chronic pancreatitis. Clinical presentation includes diabetes of the exocrine pancreas (DEP). HP prevalence ranges from 0.3 to 0.57 per 100,000 people, with up to 80% of these develop DEP. This condition often requires specific interventions: with regard to metabolic control, metformin is the first choice for those with mild DEP, and for those in advanced disease, insulin is considered the first-line therapy. Insulin analogues and insulin pump therapy are preferred due to the brittle glycemic pattern and risk of hypoglycemia. In case of exocrine insufficiency, pancreatic enzyme replacement therapy is recommended. Pancreatic polypeptide administration is a promising novel treatment feature. DEP due to HP appears to be a misdiagnosed condition. The requirement of specific management demonstrates the importance of this matter; therefore, appropriate recognition and classification are important.

Topics: Acute Disease; Carcinoma, Pancreatic Ductal; Chymotrypsin; Diabetes Complications; Diabetes Mellitus; Exocrine Pancreatic Insufficiency; Fibrosis; Humans; Pancreas, Exocrine; Pancreatic Neoplasms; Pancreatitis, Chronic; Recurrence; Risk Factors; Trypsin; Trypsin Inhibitor, Kazal Pancreatic

Exocrine pancreatic insufficiency in children can lead to lifelong complications related to malnutrition and poor growth. The clinical presentation can be subtle in the early stages of insufficiency as the large functional capacity of the pancreas is gradually lost. The pediatrician plays a crucial role in the early identification of these children to ensure a timely referral so that a diagnosis can be made and therapy initiated. Early nutritional therapy allows for prevention and correction of deficiencies, which leads to improved outcomes and survival. When insufficiency is suspected, the workup should start with an indirect test of exocrine pancreatic function, such as fecal elastase, to establish the diagnosis. Once a diagnosis is established, further testing to delineate the etiology should be pursued, with cystic fibrosis being high on the differential list and assessed for with a sweat test. Assessment of anthropometry at every visit is key, as is monitoring of laboratory parameters and physical examination findings that are suggestive of malabsorption and malnutrition. The mainstay of management is administration of exogenous pancreatic enzymes to facilitate digestion and absorption. [Pediatr Ann. 2019;48(11):e441-e447.].

Topics: Acyl-CoA Dehydrogenase, Long-Chain; Anus, Imperforate; Child; Child Nutrition Disorders; Chymotrypsin; Congenital Bone Marrow Failure Syndromes; Cystic Fibrosis; Dietary Fats; Ectodermal Dysplasia; Enzyme Replacement Therapy; Exocrine Pancreatic Insufficiency; Feces; Growth Disorders; Hearing Loss, Sensorineural; Humans; Hypothyroidism; Intellectual Disability; Lipid Metabolism, Inborn Errors; Mitochondrial Diseases; Muscular Diseases; Nose; Nutrition Assessment; Pancreas; Pancreatic Diseases; Pancreatic Elastase; Pancreatic Function Tests; Pancreatitis, Chronic; Shwachman-Diamond Syndrome; Steatorrhea; Trypsinogen

For many years, the classification of chronic pancreatitis has been oversimplified according to whether the cause is alcoholic (60-70% of cases according to published series) or non-alcoholic (20-40% of the remaining cases). Recognition of smoking as an important risk factor and increasing identification of factors of genetic susceptibility have placed these percentages in doubt and have led to a reconceptualization of the disease as a multifactorial process. Mutations in the PRSS1, SPINK1 and CFTR genes have been confirmed as major risk factors, while mutations in the CTRC and CASR genes are considered lesser risk factors for the development of chronic pancreatitis. These genetic variants are expressed in a much higher percentage of patients with chronic pancreatitis than could be expected by chance. The trans-heterozygous combination multiplies the risk of chronic pancreatitis and demonstrates the degree of complexity of the etiopathogenic mechanisms of the disease. Ductal obstruction and autoimmunity are other important etiologic factors of chronic pancreatitis that need a specific review. The present article reviews the latest studies evaluating the role of alcohol and smoking in chronic pancreatitis and the most significant genetic factors.

Topics: Autoimmune Diseases; Carrier Proteins; Cholestasis; Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; Duodenal Obstruction; Genetic Predisposition to Disease; Humans; Ischemia; Kidney Failure, Chronic; Mutation; Pancreas; Pancreatitis, Alcoholic; Pancreatitis, Chronic; Radiation Injuries; Receptors, Calcium-Sensing; Risk Factors; Smoking; Trypsin; Trypsin Inhibitor, Kazal Pancreatic

Chronic pancreatitis (CP) is a disease characterized by irreversible destruction and fibrosis of the parenchyma, leading to pancreatic exocrine insufficiency. In developed countries, the etiology for 60% to 70% of CP amongst male patients is alcohol and 25% are classified as idiopathic chronic pancreatitis (ICP). The genetic predisposition to CP could be an inappropriate activation of trypsinogen in the pancreas. Two common haplotypes, c.101A>G (p.N34S) and c.-215G>A, and four intronic alterations of the serine protease inhibitor Kazal type 1 (SPINK1) gene have been found to increase the risk for CP in the Asia Pacific region. Hence, SPINK1 is thought to be a candidate gene for pancreatitis. A loss-of-function alteration in chymotrypsinogen C (CTRC) gene has been shown to be associated with tropical calcific pancreatitis (TCP). Cathepsin B (CTSB) is also found to be associated with TCP. However mutations in cationic and anionic trypsinogen gene do not play an important role in causing CP in Asia Pacific region.

Topics: Asia; Carrier Proteins; Cathepsin B; Chymotrypsin; Genetic Association Studies; Humans; Oceania; Pancreatitis, Chronic; Trypsin; Trypsin Inhibitor, Kazal Pancreatic; Trypsin Inhibitors; Trypsinogen

Chronic pancreatitis is a persistent inflammatory disorder characterized by destruction of the pancreatic parenchyma, maldigestion, and chronic pain. Mutations in the chymotrypsin C (CTRC) gene encoding the digestive enzyme CTRC have been shown to increase the risk of chronic pancreatitis in European and Asian populations. Here, we review the biochemical properties and physiological functions of human CTRC, summarize the functional defects associated with CTRC mutations, and discuss mechanistic models that might explain the increased disease risk in carriers.

Topics: Amino Acid Sequence; Chymotrypsin; Genetic Predisposition to Disease; Humans; Molecular Sequence Data; Mutation; Pancreatitis, Chronic; Phenotype; Risk Assessment; Risk Factors

Chronic pancreatitis is a syndrome characterized by chronic inflammation of the pancreas, with variable pain, calcifications, necrosis, fatty replacement, fibrosis and scarring and other complications. Disease susceptibility, severity, progression and pain patterns vary widely and do not necessarily parallel one another. Much of the variability in susceptibility to recurrent acute and chronic pancreatitis is now clearly shown to be related to genetic differences between patients. This review highlights recent advances and future directions in genetic research.. The strongest risk factors are associated with genetic variations in PRSS1, SPINK1, CFTR, and to a lesser extent, CTRC and CASR. The latest research suggest that a single factor rarely causes pancreatitis, and the majority of patients with recurrent acute and chronic pancreatitis have multiple variants in a gene, or epistatic interactions between multiple genes, coupled with environmental stressors.. Pancreatic diseases have a strong genetic component. Rather than a classic Mendelian disorder, recurrent acute and chronic pancreatitis represents truly complex diseases with the interaction and synergism of multiple genetic and environmental factors. The future will require new predictive models to guide prevention and therapy.

Topics: Carrier Proteins; Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; Epistasis, Genetic; Genetic Predisposition to Disease; Humans; Pancreatitis, Chronic; Receptors, Calcium-Sensing; Recurrence; Trypsin; Trypsin Inhibitor, Kazal Pancreatic

Chronic pancreatitis is a persistent inflammatory disorder of the pancreas, characterized by destruction of the pancreatic parenchyma, maldigestion, chronic pain and diabetes mellitus. Genetic factors determining susceptibility to chronic pancreatitis can be classified in two groups: 1. rare gene mutations affecting the cationic trypsinogen gene that directly cause the disease, and 2. genetic variants that increase the risk for chronic pancreatitis but require additional risk factors to precipitate the disease. These gene variants are considered genetic risk factors, which emerged during the past decade and now represent a clinically important etiological category. Susceptibility to chronic pancreatitis is inherited in a complex manner, which can involve alterations in several genes conferring various degrees of risk. The biochemical mechanism behind the genetic risk includes increased ectopic activation of the digestive enzyme trypsin in the pancreas and failure of protective mechanisms responsible for trypsin inactivation.

Topics: Carrier Proteins; Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; Genetic Predisposition to Disease; Genetic Variation; Humans; Mutation; Pancreatitis, Chronic; Risk Factors; Trypsin; Trypsin Inhibitor, Kazal Pancreatic; Trypsinogen

Chronic pancreatitis is an inflammatory disease of the pancreas leading to progressive fibrosis that presents with severe abdominal pain and may result in exocrine and/or endocrine insufficiency at later stages. Although alcohol is the strongest contributing factor for disease development, some patients feature none of the known classical risk factors and were consequently classified as having idiopathic or, in the presence of a positive family history, hereditary disease. Today, several mutations have been identified that predispose carriers to development of chronic pancreatitis. The genetic studies of the past decade have clearly contributed to a better understanding of the disease's pathogenesis. Currently known mutations associated with chronic pancreatitis and the implications for clinicians are discussed in this review.

Topics: Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; Female; Gene Expression Regulation; Genetic Predisposition to Disease; Genetic Testing; Humans; Incidence; Male; Mutation; Pancreatitis, Chronic; Practice Guidelines as Topic; Prognosis; Risk Assessment; Trypsinogen

The Food and Drug Administration in 2006 required that all pancreatic enzyme products demonstrate bioavailability of lipase, amylase, and protease in the proximal small intestine.. In this phase I open-label, randomized, crossover trial, 17 adult chronic pancreatitis (CP) patients with severe exocrine pancreatic insufficiency (EPI) underwent two separate gastroduodenal perfusion procedures (Dreiling tube suctioning and [. Zenpep administration with a test meal was associated with significant increase in duodenal aspiration of lipase (p = 0.046), chymotrypsin (p = 0.008), and amylase (p = 0.001), compared to the test meal alone, indicating release of enzymes to the duodenum. Lipase delivery was higher in the pH subpopulation (the efficacy population with acid hypersecretors excluded) (p = 0.01). Recovery of [. In CP patients with severe EPI, lipase, chymotrypsin and amylase were released rapidly into the duodenum after ingestion of Zenpep plus meal compared to meals alone. Results also reflected the known pH threshold for enzyme release from enteric coated products.

Topics: Adult; Aged; Amylases; Biological Availability; Cholecystokinin; Chymotrypsin; Cross-Over Studies; Drug Delivery Systems; Duodenum; Exocrine Pancreatic Insufficiency; Female; Humans; Intestine, Small; Lipase; Male; Middle Aged; Pancreatic Extracts; Pancreatitis, Chronic; Trypsin; Young Adult

Tailored organ-sparing procedures have been shown to alleviate pain and are potentially superior in terms of preservation of endocrine and exocrine function as compared with standard resection (Whipple) for chronic pancreatitis with inflammatory pancreatic head tumor. Long-term results comparing these 2 procedures have not been published so far. The aim of this study was to report on long-term results of a randomized trial comparing a classical resective procedure (pylorus-preserving Whipple) with an extended drainage procedure (Frey) for chronic pancreatitis.. All patients who participated in a previously published randomized trial on the perioperative course comparing both procedures were contacted with a standardized, validated, quality of life and pain questionnaire. Additionally, patients were seen in the outpatient clinic to assess endocrine and exocrine pancreatic function by an oral glucose tolerance test and fecal chymotrypsin test.. There were no differences between both groups regarding quality of life, pain control, or other somatic parameters after a median of 7 years postoperatively. Correlations among continuous alcohol consumption, endocrine or exocrine pancreatic function, and pain were not found.. Both procedures provide adequate pain relief and quality of life after long-term follow-up with no differences regarding exocrine and endocrine function. However, short-term results favor the organ-sparing procedure.

Topics: Aged; Blood Glucose; Chymotrypsin; Drainage; Feces; Female; Follow-Up Studies; Germany; Humans; Male; Middle Aged; Pancreaticoduodenectomy; Pancreatitis, Chronic; Quality of Life; Retrospective Studies; Surveys and Questionnaires; Survival Rate; Time Factors; Treatment Outcome

Genetic alterations in digestive enzymes have been associated with chronic pancreatitis (CP). Recently, chymotrypsin like elastase 3B (CELA3B) emerged as a novel risk gene. Thus, we evaluated CELA3B in two European cohorts with CP.. We analyzed all 8 CELA3B exons in 550 German non-alcoholic CP (NACP) patients and in 241 German controls by targeted DNA sequencing. In addition, we analyzed exons 6 and 7 by Sanger sequencing and the c.129+1G>A variant by melting curve analysis in 1078 further German controls. As replication cohort, we investigated up to 243 non-German European NACP patients and up to 1665 controls originating from Poland, Hungary, and Sweden. We assessed the cellular secretion and the elastase activity of recombinant CELA3B variants.. In the German discovery cohort, we detected a splice-site variant in intron 2, c.129+1G>A, in 9/550 (1.64%) CP patients and in 5/1319 (0.38%) controls (P=0.007, OR=4.4, 95% CI=1.5-13.0). In the European replication cohort, this variant was also enriched in patients (9/178 [5.06%]) versus controls (13/1247 [1.04%]) (P=0.001, OR=5.1, 95% CI=2.1-12.0). We did not find the two previously reported codon 90 variants, p.R90C and p.R90L.. Our data indicate that CELA3B is a susceptibility gene for CP. In contrast to previous reports suggesting that increased CELA3B activity is associated with CP risk, the splice-site variant identified here is predicted to cause diminished CELA3B expression. How reduced CELA3B function predisposes to pancreatitis remains to be elucidated.

Topics: Chymotrypsin; Genetic Predisposition to Disease; Humans; Mutation; Pancreatic Elastase; Pancreatitis, Chronic

/Objectives: A recent Genome-wide Association Study (GWAS) in alcoholic chronic pancreatitis (ACP) identified a novel association with the CTRB1-CTRB2 (chymotrypsinogen B1, B2) locus, linked to a 16.6 kb inversion that was confirmed in non-alcoholic chronic pancreatitis (NACP). Moreover, recent findings on the function of CTRB1 and CTRB2 suggest a protective role in pancreatitis development. The aim of the present study was to investigate the CTRB1-CTRB2 locus for rare genetic variants associated with chronic pancreatitis (CP).. We analyzed 134 patients with ACP and 203 patients with NACP and compared them to up to 258 healthy controls. Genotyping was performed with polymerase chain reaction, followed by Sanger sequencing of all exons and the exon-intron-boundaries of CTRB1 and CTRB2. Finally, in silico analyses of the identified variants were conducted.. None of the seven rare missense variants or the single 5'-UTR variant in CTRB1 and CTRB2 was associated with ACP or NACP. In silico analysis predicted that variant p. Trp5Leu in CTRB1 and variant c.-4C > T in CTRB2 might alter protein expression and variants p. Asp222His in CTRB1 and p. Ala247Thr in CTRB2 might affect protein function. However, all of these variants were also described in public databases.. The present study did not reveal an association of rare variants in CTRB1 and CTRB2 with ACP or NACP. Although rare missense variants were almost exclusively found in patients, only four variants were predicted to affect protein expression or function. Thus, a major influence of rare variants in the CTRB1-CTRB2 locus on CP development is unlikely.

Topics: Chymotrypsin; Genome-Wide Association Study; Humans; Pancreatitis, Chronic; Sequence Analysis, DNA

Genetic mutations are one of the etiological factors that predispose people to develop chronic pancreatitis.. The aim of our study was to examine the effect of p.Trp55*, p.Arg254Trp and c.738_761del mutations in the chemotrypsin gene (CTRC) on the development of alcoholic chronic pancreatitis (ACP) in order to answer the questions whether these mutations vary between gender groups, whether they were related to the age when ACP was first diagnosed, and whether they affected the morphological changes in the pancreas and the course of ACP.. The study included 124 patients with ACP, 52 with nonalcoholic pancreatitis and 52 controls. The p.Trp55*, c.738_761del and p.Arg254Trp mutations in the CTRC gene were tested by the polymerase chain reaction (PCR).. The c.738_761del and p.Arg254Trp mutations occurred in 3.07% and 1.31% of cases, respectively. None of the examined patients were found to have the p.Trp55* mutation. The frequency of detected mutations did not significantly differ between the study groups. The c.738_761del mutation was detected more frequently in women than in men. No significant differences were found in the age at ACP onset, morphological changes affecting the pancreas, or in the course of ACP between the patients with and without the 2 examined mutations. The c.738_761del mutation was significantly more frequent in the diabetic patients than in the non-diabetics. The patients with this mutation more frequently required surgery than those without the c.738_761del mutation.. No relationship between the c.738_761del and p.Arg254Trp mutations and the development of APC was found. The c.738_761del mutation was more frequent in females than in males. Neither mutation affected the patient's age at ACP onset or its course. In contrast to p.Arg254Trp, the c.738_761del mutation correlated with diabetes development and the need for surgery in the course of ACP.

Topics: Chymotrypsin; Female; Genetic Predisposition to Disease; Humans; Male; Mutation; Pancreatitis; Pancreatitis, Alcoholic; Pancreatitis, Chronic; Poland; Polymerase Chain Reaction; Trypsin Inhibitor, Kazal Pancreatic; White People

Rare pathogenic variants in the SPINK1, PRSS1, CTRC, and CFTR genes have been strongly associated with a risk of developing chronic pancreatitis (CP). However, their potential impact on the age of disease onset and clinical outcomes, as well as their potential interactions with environmental risk factors, remain unclear. These issues are addressed here in a large Chinese CP cohort.. We performed targeted next-generation sequencing of the four CP-associated genes in 1061 Han Chinese CP patients and 1196 controls. To evaluate gene-environment interactions, the patients were divided into three subgroups, idiopathic CP (ICP; n = 715), alcoholic CP (ACP; n = 206), and smoking-associated CP (SCP; n = 140). The potential impact of rare pathogenic variants on the age of onset of CP and clinical outcomes was evaluated using the Kaplan-Meier model.. We identified rare pathogenic genotypes involving the SPINK1, PRSS1, CTRC, and/or CFTR genes in 535 (50.42%) CP patients but in only 71 (5.94%) controls (odds ratio = 16.12; P < 0.001). Mutation-positive patients had significantly earlier median ages at disease onset and at diagnosis of pancreatic stones, diabetes mellitus and steatorrhea than mutation-negative ICP patients. Pathogenic genotypes were present in 57.1, 39.8, and 32.1% of the ICP, ACP, and SCP patients, respectively, and influenced age at disease onset and clinical outcomes in all subgroups.. We provide evidence that rare pathogenic variants in the SPINK1, PRSS1, CTRC, and CFTR genes significantly influence the age of onset and clinical outcomes of CP. Extensive gene-environment interactions were also identified.

Topics: Adolescent; Adult; Age of Onset; Asian People; Calculi; Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; Diabetes Mellitus; Gene-Environment Interaction; Genetic Predisposition to Disease; Genotype; Humans; Kaplan-Meier Estimate; Middle Aged; Mutation; Pancreatic Diseases; Pancreatitis, Alcoholic; Pancreatitis, Chronic; Smoking; Steatorrhea; Trypsin; Trypsin Inhibitor, Kazal Pancreatic; Young Adult

To assess whether the age of onset was associated with unique features or disease course in pediatric acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP).. Demographic and clinical information on children with ARP or CP was collected at INSPPIRE (INternational Study Group of Pediatric Pancreatitis: In Search for a CuRE) centers. The Cochran-Armitage trend test and Jonckheere-Terpstra test were used to examine for differences between pediatric age groups (<6, 6-11, and ≥12 years).. Between September 2012 and March 2016, 342 children with ARP or CP were enrolled; 129 (38%) were <6 years of age at the time of first diagnosis of acute pancreatitis, 111 (32%) were 6-11 years of age, and 102 (30%) were ≥12 years of age. Early-onset disease was associated with mutations in cationic trypsinogen (PRSS1) (P < .01), chymotrypsin C (CTRC) (P = .01), family history of acute pancreatitis (P = .02), family history of CP (P < .01), biliary cysts (P = .04), or chronic renal failure (P = .02). Later-onset disease was more commonly present with hypertriglyceridemia (P = .04), ulcerative colitis (P = .02), autoimmune diseases (P < .0001), or medication use (P < .01). Children with later-onset disease also were more likely to visit the emergency department (P < .05) or have diabetes (P < .01).. Early-onset pancreatitis is associated strongly with PRSS1 or CTRC mutations and family history of pancreatitis. Children with later-onset disease are more likely to have nongenetic risk factors. Future studies are needed to investigate whether the disease course, response to therapy, or clinical outcomes differ relative to the timing of disease onset.

Topics: Acute Disease; Adolescent; Age of Onset; Child; Child, Preschool; Chymotrypsin; Cohort Studies; Female; Genetic Predisposition to Disease; Humans; Male; Mutation; Pancreatitis, Chronic; Recurrence; Trypsin

Mutations in the PRSS1 gene encoding human cationic trypsinogen are associated with hereditary and sporadic chronic pancreatitis. High-penetrance PRSS1 mutations found in hereditary pancreatitis alter activation and/or degradation of cationic trypsinogen, thereby promoting intrapancreatic trypsinogen activation. In contrast, a number of rare PRSS1 variants identified in subjects with sporadic chronic pancreatitis cause misfolding and endoplasmic reticulum (ER) stress. Mutation p.L104P is unique among natural PRSS1 variants, since it affects the substrate binding site of trypsin. The aim of the present study was to establish the clinical significance of variant p.L104P through functional analysis. We found that p.L104P trypsin exhibited decreased activity on peptide and protein substrates; however, autoactivation was slightly accelerated. Remarkably, binding of the physiological trypsin inhibitor serine protease inhibitor Kazal type 1 (SPINK1) was decreased by 70-fold. In the presence of the trypsinogen-degrading enzyme chymotrypsin C, mutant p.L104P autoactivated to higher trypsin levels than wild-type trypsinogen. This apparent resistance to degradation was due to slower cleavage at Arg(122) rather than Leu(81) Finally, secretion of mutant p.L104P from transfected cells was markedly reduced due to intracellular retention and aggregation with concomitant elevation of ER stress markers. We conclude that PRSS1 variant p.L104P exhibits a variety of phenotypic changes that can increase risk for chronic pancreatitis. Mutation-induced misfolding and associated ER stress are the dominant effects that support a direct pathogenic role in chronic pancreatitis.

Topics: Binding Sites; Carrier Proteins; Chymotrypsin; Endoplasmic Reticulum Stress; Enzyme Activation; Genetic Predisposition to Disease; HEK293 Cells; Humans; Kinetics; Models, Molecular; Mutation; Pancreatitis, Chronic; Phenotype; Protein Aggregates; Protein Binding; Protein Conformation; Protein Folding; Signal Transduction; Structure-Activity Relationship; Substrate Specificity; Transfection; Trypsin; Trypsin Inhibitor, Kazal Pancreatic

Pediatric acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP) are poorly understood.. To characterize and identify risk factors associated with ARP and CP in childhood.. A multinational cross-sectional study of children with ARP or CP at the time of enrollment to the INSPPIRE (International Study Group of Pediatric Pancreatitis: In Search for a Cure) study at participant institutions of the INSPPIRE Consortium. From August 22, 2012, to February 8, 2015, 155 children with ARP and 146 with CP (aged ≤19 years) were enrolled. Their demographic and clinical information was entered into the REDCap (Research Electronic Data Capture) database at the 15 centers. Differences were analyzed using 2-sample t test or Wilcoxon rank sum test for continuous variables and Pearson χ2 test or Fisher exact test for categorical variables. Disease burden variables (pain variables, hospital/emergency department visits, missed school days) were compared using Wilcoxon rank sum test.. Demographic characteristics, risk factors, abdominal pain, and disease burden.. A total of 301 children were enrolled (mean [SD] age, 11.9 [4.5] years; 172 [57%] female); 155 had ARP and 146 had CP. The majority of children with CP (123 of 146 [84%]) reported prior recurrent episodes of acute pancreatitis. Sex distribution was similar between the groups (57% female in both). Hispanic children were less likely to have CP than ARP (17% vs 28%, respectively; odds ratio [OR] = 0.51; 95% CI, 0.29-0.92; P = .02). At least 1 gene mutation in pancreatitis-related genes was found in 48% of patients with ARP vs 73% of patients with CP (P < .001). Children with PRSS1 or SPINK1 mutations were more likely to present with CP compared with ARP (PRSS1: OR = 4.20; 95% CI, 2.14-8.22; P < .001; and SPINK1: OR = 2.30; 95% CI, 1.03-5.13; P = .04). Obstructive risk factors did not differ between children with ARP or CP (33% in both the ARP and CP groups), but toxic/metabolic risk factors were more common in children with ARP (21% overall; 26% in the ARP group and 15% in the CP group; OR = 0.55; 95% CI, 0.31-0.99; P = .046). Pancreatitis-related abdominal pain was a major symptom in 81% of children with ARP or CP within the last year. The disease burden was greater in the CP group compared with the ARP group (more emergency department visits, hospitalizations, and medical, endoscopic, and surgical interventions).. Genetic mutations are common in both ARP and CP. Ethnicity and mutations in PRSS1 or SPINK1 may influence the development of CP. The high disease burden in pediatric CP underscores the importance of identifying predisposing factors for progression of ARP to CP in children.

Topics: Abdominal Pain; Acute Disease; Carrier Proteins; Child; Chymotrypsin; Cost of Illness; Cross-Sectional Studies; Cystic Fibrosis Transmembrane Conductance Regulator; Disease Progression; Emergency Service, Hospital; Female; Genetic Predisposition to Disease; Hospitalization; Humans; Male; Mutation; Pancreatitis; Pancreatitis, Chronic; Recurrence; Risk Factors; Trypsin; Trypsin Inhibitor, Kazal Pancreatic

Causes of acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP) are sometimes difficult to determine in children. In such patients, genetic analysis may prove helpful. The present study analyzed mutations of cationic trypsinogen (PRSS1), serine protease inhibitor Kazal type 1 (SPINK1), chymotrypsin C (CTRC), and carboxypeptidase A1 (CPA1) and investigated the clinical features of children with these mutations.. Genetic analyses of mutations in these 4 genes were conducted in 128 patients with ARP or CP. Characteristics of the patients showing mutations were investigated using medical records.. Fifty of the 128 (39.1%) subjects had at least 1 mutation (median age at onset, 7.6 years). Abdominal pain was the presenting symptom of pancreatitis in 48 of the 50 patients (96%). Fifteen of those 50 patients (30.0%) had a family history of pancreatitis. Gene mutations were present in PRSS1 in 26 patients, SPINK1 in 23, CTRC in 3, and CPA1 in 5. In the 31 patients with mutations in SPINK1, CTRC, or CPA1, 16 (51.6%) had homozygous or heterozygous mutations with other mutations. Three patients underwent surgery and another 4 patients underwent endoscopy to manage ARP or CP. Although 3 of the 7 patients complained of mild abdominal pain, none of those 7 patients experienced any obvious episode of ARP after treatment.. In pediatric patients with idiopathic ARP and CP, genetic analysis is useful for identifying the cause of pancreatitis. Early endoscopic or surgical treatment prevents ARP by extending the interval between episodes of pancreatitis in this population.

Topics: Acute Disease; Adolescent; Carboxypeptidases A; Child; Child, Preschool; Chymotrypsin; Female; Follow-Up Studies; Genetic Markers; Genetic Testing; Humans; Japan; Male; Mutation; Pancreatitis; Pancreatitis, Chronic; Recurrence; Retrospective Studies; Trypsin; Trypsin Inhibitor, Kazal Pancreatic

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

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Asian People; Carrier Proteins; Child; Child, Preschool; Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; DNA Copy Number Variations; Female; Heterozygote; Humans; Infant; Male; Middle Aged; Pancreatitis, Chronic; Polymorphism, Genetic; Republic of Korea; Trypsin; Trypsin Inhibitor, Kazal Pancreatic; Young Adult

Topics: Chymotrypsin; Humans; Pancreas; Pancreatitis, Chronic; Trypsin

Cystic fibrosis (CF), the most common autosomal recessive disease in whites, is caused by mutations in the CF transmembrane conductance regulator (CFTR). So far, >1900 mutations have been described, most of which are nonsense, missense, and frameshift, and can lead to severe phenotypes, reducing the level of function of the CFTR protein. Synonymous variations are usually considered silent without pathogenic effects. However, synonymous mutations exhibiting exon skipping as a consequence of aberrant splicing of pre-mRNA differ. Herein, we describe the effect of the aberrant splicing of the c.273G>C (G91G) synonymous variation found in a 9-year-old white (ΔF508) patient affected by CF and pancreatitis associated with a variant in chymotrypsin C (CTRC). Magnetic resonance imaging showed an atrophic pancreatic gland with substitution of the pancreatic parenchyma with three cysts. Genetic examination revealed compound heterozygosity for the c.1521_1523delCTT (ΔF508) pathogenic variant and the c.273G>C (G91G) variant in CFTR. Sweat test results confirmed the diagnosis of CF. We have thus identified a synonymous variation (G91G) causing the skipping of exon 3 in a CF patient carrying the ΔF508 mutation. However, the clinical phenotype with pancreatic symptoms encouraged us to investigate a panel of pancreas-related genes, which resulted in finding a known sequence variation inside CTRC. We further discuss the role of these variants and their possible interactions in determining the current phenotype.

Topics: Child; Chymotrypsin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Humans; Late Onset Disorders; Male; Pancreatitis, Chronic

Human chymotrypsin C (CTRC) protects against pancreatitis by degrading trypsinogen and thereby curtailing harmful intra-pancreatic trypsinogen activation. Loss-of-function mutations in CTRC increase the risk for chronic pancreatitis. Here we describe functional analysis of eight previously uncharacterized natural CTRC variants tested for potential defects in secretion, proteolytic stability, and catalytic activity. We found that all variants were secreted from transfected cells normally, and none suffered proteolytic degradation by trypsin. Five variants had normal enzymatic activity, whereas variant p.R29Q was catalytically inactive due to loss of activation by trypsin and variant p.S239C exhibited impaired activity possibly caused by disulfide mispairing. Surprisingly, variant p.G214R had increased activity on a small chromogenic peptide substrate but was markedly defective in cleaving bovine β-casein or the natural CTRC substrates human cationic trypsinogen and procarboxypeptidase A1. Mutation p.G214R is analogous to the evolutionary mutation in human mesotrypsin, which rendered this trypsin isoform resistant to proteinaceous inhibitors and conferred its ability to cleave these inhibitors. Similarly to the mesotrypsin phenotype, CTRC variant p.G214R was inhibited poorly by eglin C, ecotin, or a CTRC-specific variant of SGPI-2, and it readily cleaved the reactive-site peptide bonds in eglin C and ecotin. We conclude that CTRC variants p.R29Q, p.G214R, and p.S239C are risk factors for chronic pancreatitis. Furthermore, the mesotrypsin-like CTRC variant highlights how the same natural mutation in homologous pancreatic serine proteases can evolve a new physiological role or lead to pathology, determined by the biological context of protease function.

Topics: Amino Acid Sequence; Animals; Caseins; Cattle; Chymotrypsin; Genetic Variation; HEK293 Cells; Humans; Models, Molecular; Molecular Sequence Data; Mutation; Pancreatitis, Chronic; Protein Conformation; Recombinant Proteins; Risk Factors; Substrate Specificity; Trypsin; Trypsinogen

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.. 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.. 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.. 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.

Topics: Acute Disease; Adult; Aged; Carrier Proteins; Case-Control Studies; Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; Disease Progression; Female; Genetic Markers; Genetic Predisposition to Disease; Genotype; Genotyping Techniques; Humans; Male; Middle Aged; Mutation; Pancreatitis; Pancreatitis, Chronic; Trypsin Inhibitor, Kazal Pancreatic

Topics: Acute Disease; Child; Chymotrypsin; DNA Mutational Analysis; Female; Genetic Predisposition to Disease; Humans; Introns; Male; Middle Aged; Mutation; Pancreatitis; Pancreatitis, Chronic; Phenotype; Risk Factors; Young Adult

Hereditary pancreatitis is caused by mutations in human cationic trypsinogen (PRSS1) which lead to increased autoactivation by altering chymotrypsin C (CTRC)-dependent trypsinogen activation and degradation. Exceptions are some cysteine mutations which cause misfolding, intracellular retention and endoplasmic reticulum stress. Clinical relevance of many PRSS1 variants found in patients with sporadic chronic pancreatitis is unknown but often assumed by analogy with known disease-causing mutations. Functional comparison of PRSS1 variants found in sporadic and hereditary cases is needed to resolve this dilemma.. Here, we investigated the functional phenotype of 13 published PRSS1 variants with respect to autoactivation in the presence of CTRC and cellular secretion.. Only mutation p.D100H increased trypsinogen autoactivation, but this gain in function was offset by a marked reduction in secretion. Five mutants (p.P36R, p.G83E, p.I88N, p.V123M, p.S124F) showed decreased autoactivation due to increased degradation by CTRC. Five mutants exhibited strongly (p.D100H, p.C139F) or moderately (p.K92N, p.S124F, p.G208A) reduced secretion, whereas mutant p.K170E showed slightly increased secretion. Mutant p.I88N was also secreted to higher levels but was rapidly degraded by CTRC. Finally, three mutants (p.Q98K, p.T137M, p.S181G) had no phenotypic alterations relative to wild-type trypsinogen.. Rare PRSS1 variants found in sporadic chronic pancreatitis do not stimulate autoactivation but may cause increased degradation, impaired secretion or no functional change. Variants with reduced secretion are likely pathogenic due to mutation-induced misfolding and consequent endoplasmic reticulum stress.

Topics: Blotting, Western; Cell Culture Techniques; Chymotrypsin; Electrophoresis, Polyacrylamide Gel; Genetic Predisposition to Disease; Genetic Variation; Humans; Mutation; Pancreas; Pancreatitis, Chronic; Phenotype; Trypsin

Topics: Chymotrypsin; Humans; Pancreas; Pancreatitis, Chronic; Trypsin

Topics: Carrier Proteins; Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; Female; Humans; Male; Pancreatitis, Chronic; Trypsin

Mutations in the cationic trypsinogen (PRSS1), cystic fibrosis transmembrane conductance regulator (CFTR), serine protease inhibitor Kazal type 1 (SPINK1), and chymotrypsin C (CTRC) genes are associated with an elevated risk for chronic pancreatitis, which is a known risk factor for pancreatic cancer (PC). Therefore, we analyzed whether PRSS1, CFTR, SPINK1, and/or CTRC mutations are associated with pancreatic adenocarcinoma.. The study cohort was composed of 121 PC patients, of whom 74 were classified as having chronic pancreatitis, 102 patients with idiopathic chronic pancreatitis, and 130 as healthy controls. Mutation analyses for the CFTR, SPINK1, PRSS1, and CTRC genes were performed for the presence of the most common mutations.. The frequency of CFTR mutations in patients with PC was not significantly different in comparison with healthy controls and controls with pancreatitis. The SPINK1 mutation frequency was significantly decreased in patients with PC in comparison with patients with idiopathic pancreatitis but varied not significantly in comparison with healthy controls. None of the selected 121 PC samples showed a pancreatitis-predisposing mutation in the PRSS1 or CTRC gene.. Mutations in the genes CFTR, SPINK1, PRSS1, and CTRC do not seem to significantly increase the risk for pancreatic adenocarcinoma.

Topics: Adult; Aged; Aged, 80 and over; Alleles; Carcinoma, Pancreatic Ductal; Carrier Proteins; Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; DNA Mutational Analysis; DNA, Neoplasm; Female; Genetic Predisposition to Disease; Germany; Humans; Male; Middle Aged; Neoplasm Proteins; Pancreatic Neoplasms; Pancreatitis, Chronic; Precancerous Conditions; Retrospective Studies; Trypsin; Trypsin Inhibitor, Kazal Pancreatic

The diagnosis of chronic pancreatitis remains challenging in early stages of the disease. This report defines the diagnostic criteria useful in the assessment of patients with suspected and established chronic pancreatitis. All current diagnostic procedures are reviewed, and evidence-based statements are provided about their utility and limitations. Diagnostic criteria for chronic pancreatitis are classified as definitive, probable, or insufficient evidence. A diagnostic (STEP-wise; survey, tomography, endoscopy, and pancreas function testing) algorithm is proposed that proceeds from a noninvasive to a more invasive approach. This algorithm maximizes specificity (low false-positive rate) in subjects with chronic abdominal pain and equivocal imaging changes. Furthermore, a nomenclature is suggested to further characterize patients with established chronic pancreatitis based on TIGAR-O (toxic, idiopathic, genetic, autoimmune, recurrent, and obstructive) etiology, gland morphology (Cambridge criteria), and physiologic state (exocrine, endocrine function) for uniformity across future multicenter research collaborations. This guideline will serve as a baseline manuscript that will be modified as new evidence becomes available and our knowledge of chronic pancreatitis improves.

Topics: Calcinosis; Cholangiopancreatography, Magnetic Resonance; Chymotrypsin; Diagnosis, Differential; Disease Progression; Endoscopy, Digestive System; Endosonography; Evidence-Based Medicine; Feces; Humans; Incidence; Pancreatic Elastase; Pancreatic Function Tests; Pancreatic Neoplasms; Pancreatitis, Alcoholic; Pancreatitis, Chronic; Risk Factors; Secretin; Sensitivity and Specificity; Severity of Illness Index; Smoking; Steatorrhea; Tomography, X-Ray Computed

Mutations in human cationic trypsinogen cause hereditary pancreatitis by altering its proteolytic regulation of activation and degradation by chymotrypsin C (CTRC). CTRC stimulates trypsinogen autoactivation by processing the activation peptide to a shorter form, but also promotes degradation by cleaving the calcium-binding loop in trypsinogen. Mutations render trypsinogen resistant to CTRC-mediated degradation and/or increase processing of the activation peptide by CTRC. Here we demonstrate that the activation peptide mutations D19A, D22G, K23R and K23_I24insIDK robustly increased the rate of trypsinogen autoactivation, both in the presence and absence of CTRC. Degradation of the mutants by CTRC was unchanged, and processing of the activation peptide was increased fourfold in the D19A mutant only. Surprisingly, however, this increased processing had only a minimal effect on autoactivation. The tetra-aspartate motif in the trypsinogen activation peptide binds calcium (KD of ~ 1.6 mM), which stimulates autoactivation. Unexpectedly, calcium binding was not compromised by any of the activation peptide mutations. Despite normal binding, autoactivation of mutants D22G and K23_I24insIDK was not stimulated by calcium. Finally, the activation peptide mutants exhibited reduced secretion from transfected cells, and secreted trypsinogen levels were inversely proportional with autoactivation rates. We conclude that D19A, D22G, K23R and K23_I24insIDK form a mechanistically distinct subset of hereditary pancreatitis-associated mutations that exert their effect primarily through direct stimulation of autoactivation, independently of CTRC. The potentially severe clinical impact of the markedly increased autoactivation is offset by diminished secretion, resulting in a clinical phenotype that is indistinguishable from typical hereditary pancreatitis.

Topics: Calcium; Chymotrypsin; Enzyme Activation; HEK293 Cells; Humans; Mutation, Missense; Pancreatitis, Chronic; Peptide Fragments; Protein Binding; Proteolysis; Trypsin; Trypsinogen

Novel variants associated with chronic pancreatitis are being increasingly reported. However, most studies have so far only analyzed point mutations and small insertions or deletions. Here we report the characterization of two distinct deletions of the CTRC locus. Variants in four chronic pancreatitis genes, PRSS1, SPINK1, CTRC and CFTR, were systematically analyzed in the studied cases. Copy number change of the CTRC gene was analyzed by quantitative fluorescent multiplex PCR (QFM-PCR). Walking QFM-PCR followed by long-range PCR and direct sequencing were employed to identify the deletion breakpoints at the nucleotide level. A heterozygous CTRC-deleting complex rearrangement, which was co-inherited with different trans variants in SPINK1, CFTR or PRSS1, is associated with variable phenotypes (chronic pancreatitis; pancreatic cancer and chronic pancreatitis; and type 1 diabetes). Moreover, a different homozygous deletion of the CTRC locus was found in an unrelated patient with asymptomatic chronic pancreatitis. Our findings revealed a hitherto unrecognized level of complexity of genotype-phenotype correlation in chronic pancreatitis. The CTRC-deleting complex rearrangement probably resulted from LINE-1-mediated Alu insertion, which represents a novel mutational mechanism causing chronic pancreatitis.

Topics: Adult; Chymotrypsin; DNA Mutational Analysis; Gene Deletion; Genetic Loci; Heterozygote; Homozygote; Humans; Male; Pancreatitis, Chronic; Pedigree; Young Adult

Idiopathic chronic pancreatitis (ICP) has traditionally been defined as chronic pancreatitis in the absence of any obvious precipitating factors (e.g. alcohol abuse) and family history of the disease. Studies over the past 15 years have revealed that ICP has a highly complex genetic architecture involving multiple gene loci. Here, we have attempted to provide a conservative assessment of the major genetic causes of ICP in a sample of 253 young French ICP patients. For the first time, conventional types of mutation (comprising coding sequence variants and variants at intron/exon boundaries) and gross genomic rearrangements were screened for in all four major pancreatitis genes, PRSS1, SPINK1, CTRC and CFTR. For the purposes of the study, synonymous, intronic and 5'- or 3'-untranslated region variants were excluded from the analysis except where there was persuasive evidence of functional consequences. The remaining sequence variants/genotypes were classified into causative, contributory or neutral categories by consideration of (i) their allele frequencies in patient and normal control populations, (ii) their presumed or experimentally confirmed functional effects, (iii) the relative importance of their associated genes in the pathogenesis of chronic pancreatitis and (iv) gene-gene interactions wherever applicable. Adoption of this strategy allowed us to assess the pathogenic relevance of specific variants/genotypes to their respective carriers to an unprecedented degree. The genetic cause of ICP could be assigned in 23.7% of individuals in the study group. A strong genetic susceptibility factor was also present in an additional 24.5% of cases. Taken together, up to 48.2% of the studied ICP patients were found to display evidence of a genetic basis for their pancreatitis. Whereas these particular proportions may not be extrapolable to all ICP patients, the approach employed should serve as a useful framework for acquiring a better understanding of the role of genetic factors in causing this oligogenic disease.

Topics: Adult; Carrier Proteins; Chymotrypsin; Cohort Studies; Cystic Fibrosis Transmembrane Conductance Regulator; Epistasis, Genetic; Female; France; Genotype; Humans; Male; Mutation; Pancreatitis, Chronic; Trypsin; Trypsin Inhibitor, Kazal Pancreatic; Young Adult

In chronic pancreatitis (CP), alterations in several genes have so far been described, but only small cohorts have been extensively investigated for all predisposing genes.. 660 patients with idiopathic or hereditary CP and up to 1758 controls were enrolled. PRSS1, SPINK1 and CTRC were analysed by DNA sequencing, and cystic fibrosis transmembrane conductance regulator (CFTR) by melting curve analysis.. Frequencies of CFTR variants p.R75Q, p.I148T, 5T-allele and p.E528E were comparable in patients and controls. We identified 103 CFTR variants, which represents a 2.7-fold risk increase (p<0.0001). Severe cystic fibrosis (CF)-causing variants increased the risk of developing CP 2.9-fold, and mild CF-causing variants 4.5-fold (p<0.0001 for both). Combined CF-causing variants increased CP risk 3.4-fold (p<0.0001), while non-CF-causing variants displayed a 1.5-fold over-representation in patients (p=0.14). CFTR compound heterozygous status with variant classes CF-causing severe and mild represented an OR of 16.1 (p<0.0001). Notably, only 9/660 (1.4%) patients were compound heterozygotes in this category. Trans-heterozygosity increased CP risk, with an OR of 38.7, with 43/660 (6.5%) patients and 3/1667 (0.2%) controls being trans-heterozygous (p<0.0001).. Accumulation of CFTR variants in CP is less pronounced than reported previously, with ORs between 2.7 and 4.5. Only CF-causing variants reached statistical significance. Compound and trans-heterozygosity is an overt risk factor for the development of CP, but the number of CFTR compound heterozygotes in particular is rather low. In summary, the study demonstrates the complexity of genetic interactions in CP and a minor influence of CFTR alterations in CP development.

Topics: Adolescent; Adult; Aged; Alleles; Carrier Proteins; Case-Control Studies; Child; Child, Preschool; Chymotrypsin; Cystic Fibrosis Transmembrane Conductance Regulator; Female; Genetic Predisposition to Disease; Genetic Variation; Genotype; Humans; Infant; Male; Middle Aged; Pancreatitis, Chronic; Polymerase Chain Reaction; Risk Factors; Sequence Analysis, DNA; Trypsin; Trypsin Inhibitor, Kazal Pancreatic

In a previous study, the authors have shown that rather than variants in trypsinogen gene(s), mutations in pancreatic secretory trypsin inhibitor (encoded by SPINK1) and cathepsin B (CTSB) are associated with tropical calcific pancreatitis (TCP). Recently, chymotrypsin C (CTRC) variants that diminish its activity or secretion were found to predict susceptibility to chronic pancreatitis (CP). The authors analysed CTRC variants in a large, ethnically matched case-control TCP cohort.. The authors sequenced all eight exons and flanking regions in CTRC in 584 CP patients (497 TCP, 87 idiopathic CP) and 598 normal subjects and analysed the significance of association using χ(2) test. The authors also investigated interaction of CTRC variants with p.N34S SPINK1 and p.L26V CTSB mutations.. The authors identified 14 variants in CTRC, of which non-synonymous variants were detected in 71/584 CP patients (12.2%) and 22/598 controls (3.7%; OR 3.62, 95% CI 2.21 to 5.93; p=6.2 × 10(-8)). Rather than the commonly reported p.K247_R254del variant in Caucasians, p.V235I was the most common mutation in Indian CP patients (28/575 (4.9%); OR 7.60, 95% CI 2.52 to 25.71; p=1.01 × 10(-5)). Another pathogenic variant, p.A73T was identified in 3.1% (18/584) patients compared with 0.3% (2/598) in controls (OR=9.48, 95% CI 2.19 to 41.03, p=2.5 × 10(-4)). The authors also observed significant association for the synonymous variant c.180C>T (p.(=)) with CP (OR 2.71, 95% CI 1.79 to 4.12, p=5.3 × 10(-7)). Two novel nonsense mutations, p.G242AfsX9 and p.W113X were also identified exclusively in CP patients. No interaction between CTRC variants and p.N34S SPINK1 or p.L26V CTSB mutations was observed.. This study on a large cohort of TCP patients provides evidence of allelic heterogeneity and confirms that CTRC variants play a significant role in its pathogenesis.

Topics: Calcinosis; Carrier Proteins; Case-Control Studies; Cathepsin B; Chymotrypsin; Genetic Predisposition to Disease; Genotype; Humans; Mutation; Pancreatitis, Chronic; Trypsin Inhibitor, Kazal Pancreatic

The digestive enzyme chymotrypsin C (CTRC) protects against pancreatitis by promoting degradation of trypsinogen, thereby curtailing potentially harmful trypsinogen activation. Loss-of-function variants in CTRC increase the risk for chronic pancreatitis. The aim of the present study was to perform comprehensive functional analysis of all missense CTRC variants identified to date.. We investigated secretion, activity and degradation of 27 published and five novel CTRC mutants. We also assessed the effect of five mutants on endoplasmic reticulum (ER) stress.. None of the mutants exhibited a gain of function, such as increased secretion or activity. By contrast, 11 mutants showed marked loss of function, three mutants had moderate functional defects, whereas 18 mutants were functionally similar to wild-type CTRC. The functional deficiencies observed were diminished secretion, impaired catalytic activity and degradation by trypsin. Mutants with a secretion defect caused ER stress that was proportional to the loss in secretion. ER stress was not associated with loss-of-function phenotypes related to catalytic defect or proteolytic instability.. Pathogenic CTRC variants cause loss of function by three distinct but mutually non-exclusive mechanisms that affect secretion, activity and proteolytic stability. ER stress may be induced by a subset of CTRC mutants, but does not represent a common pathological mechanism of CTRC variants. This phenotypic dataset should aid in the classification of the clinical relevance of CTRC variants identified in patients with chronic pancreatitis.

Topics: Biocatalysis; Chymotrypsin; Culture Media, Conditioned; Endoplasmic Reticulum Stress; Genetic Predisposition to Disease; Genetic Variation; HEK293 Cells; Humans; Mutation, Missense; Pancreatitis, Chronic; Trypsin

Topics: Asian People; Case-Control Studies; Chymotrypsin; Exons; Female; Genetic Predisposition to Disease; Genetic Variation; Humans; Male; Mutation, Missense; Pancreatitis, Chronic

Chronic pancreatitis is a progressive inflammatory disorder of the pancreas characterised by permanent destruction of acinar cells. Mutations in the chymotrypsinogen C (CTRC) gene have been linked to the development of chronic pancreatitis. The aim of the present study was to explore whether CTRC mutants induce endoplasmic reticulum (ER) stress in pancreatic acinar cells.. Dexamethasone-differentiated AR42J rat acinar cells and freshly isolated mouse acini were transfected with recombinant adenovirus carrying wild-type CTRC or the p.A73T pancreatitis-associated mutant. ER stress markers were assessed by reverse transcription-PCR and western blotting. Apoptosis was characterised by caspase-3/7 activity and the TUNEL assay.. Acinar cells transfected with the p.A73T mutant, but not those with wild-type CTRC, developed significant ER stress as judged by elevated mRNA and protein levels of the ER chaperone immunoglobulin-binding protein (BiP), increased splicing of the X-box binding protein-1 (XBP1) mRNA and marked induction of the transcription factor C/EBP-homologous protein (CHOP), a mediator of ER stress-associated apoptosis. Consistent with higher CHOP expression, AR42J cells expressing the p.A73T mutant became detached over time and showed considerably increased caspase-3/7 activity and TUNEL staining.. Pancreatitis-associated CTRC mutations can markedly increase the propensity of chymotrypsinogen C to elicit ER stress in pancreatic acinar cells. Thus, carriers of CTRC mutations may be at a higher risk of developing ER stress in the exocrine pancreas, which may contribute to parenchymal damage through acinar cell apoptosis.

Topics: Adenoviridae; Animals; Apoptosis; Cells, Cultured; Chymotrypsin; eIF-2 Kinase; Endoplasmic Reticulum; Humans; Mice; NF-kappa B; Pancreas, Exocrine; Pancreatitis, Chronic; Rats; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Stress, Physiological; Transfection

Pancreatic juice is a potential source of proteins associated with pancreatic cancer (PC) due to the proximity of ducts to tumor tissue. Therefore, screening of proteins in pancreatic juice from PC patients may identify new PC biomarkers. We analyzed pancreatic juice from patients with pancreatic diseases including PC, chronic pancreatitis (CP) and simple choledocholithiasis (CDS) by 2-DE. Protein spots from PC patients that changed >2-fold compared with both CP and CDS were selected and identified by mass spectrometry (MS). mRNA levels were measured by QRT-PCR in PC cell lines, PC tissues and adjacent pancreatic normal (PN) tissues. Relationships between mRNA levels in PC tissues and their clinical characteristics and promoter methylation were analyzed in PC cell lines and tissues. We found that four proteins were significantly changed in PC compared to CP and simple CDS. Two proteins were up-regulated, serine proteinase-2 (PRSS2) preproprotein and pancreatic lipase-related protein-1 (PLRP1), and two proteins were down-regulated, chymotrypsinogen B (CTRB) precursor and elastase 3B (ELA3B) preproprotein. In all PC cell lines, PRSS 2 mRNA levels were elevated, while PLRP 1 mRNA was detected in 4/5 cell lines. ELA3B mRNA was undetectable in all cell lines, but CTRB mRNA was detected in 2/5 cell lines. In PC tissues compared to PN, levels of PRSS2 mRNA were significantly higher, ELA3B significantly lower, and PLRP1 and CTRB not significantly different. Elevated PRSS2 mRNA levels correlated with high T stage. The ELA3B gene promoter had higher methylation in PC cell lines and tissues compared with PN tissues, and correlated with low ELA3B gene expression. In conclusion, comparative proteomic analysis of pancreatic juice from PC patients is a powerful method to find new PC biomarkers. Hyperexpression of the PRSS2 gene and hypermethylation of ELA3B gene promoter were associated with PC, raising the possibility of their application as new biomarkers in PC diagnosis and screening.

Topics: Aged; Biomarkers, Tumor; Carcinoma, Pancreatic Ductal; Choledocholithiasis; Chymotrypsin; DNA Methylation; Electrophoresis, Gel, Two-Dimensional; Female; Humans; Intracellular Signaling Peptides and Proteins; Male; Middle Aged; Nuclear Proteins; Pancreas; Pancreatic Elastase; Pancreatic Juice; Pancreatic Neoplasms; Pancreatitis, Chronic; Prognosis; Promoter Regions, Genetic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Trypsin; Trypsinogen; Tumor Cells, Cultured

Variations and haplotypes of the chymotrypsin C (CTRC) gene in Chinese patients with chronic pancreatitis (CP) and control subjects with genotype-phenotype correlation were investigated.. One hundred and twenty-six patients with CP were analyzed. The entire sequence of coding regions of exons 2, 3 and 7 and their neighboring intronic regions in introns 1, 2 and 6 of the CTRC gene were analyzed using PCR sequence-specific primers and direct sequencing. The exonic region of exon 7 and the neighboring intronic region of intron 6 were also analyzed in 90 geographically matched healthy control subjects.. In total, 4 novel variations were identified in exons 2, 3 and 7 in 3 CP patients. A total of 2.3% (3/126) of our CP patients carried variations of the CTRC gene. We also first identified six new intronic variations in intron 6 which had not been reported before. The GAGGGG, GAGGAG and GAGTAG haplotypes assembled by six locus intronic variations c.640-41/c.640-40/c.640-39/c.640-37/c.640-36/c.640-35 in intron 6 were associated with a significantly higher susceptibility risk of CP (OR 66.75, 37.00, and 9.37, respectively).. Novel CTRC gene variations and haplotypes are associated with CP in a Chinese population.

Topics: Adult; Age of Onset; Amino Acid Substitution; Asian People; Base Sequence; Chymotrypsin; DNA; Exons; Genetic Predisposition to Disease; Genetic Variation; Humans; Introns; Mutation; Pancreatitis, Chronic; Polymorphism, Single Nucleotide; Taiwan

Chronic pancreatitis is a persistent inflammatory disease of the pancreas, in which the digestive protease trypsin has a fundamental pathogenetic role. Here we have analyzed the gene encoding the trypsin-degrading enzyme chymotrypsin C (CTRC) in German subjects with idiopathic or hereditary chronic pancreatitis. Two alterations in this gene, p.R254W and p.K247_R254del, were significantly overrepresented in the pancreatitis group, being present in 30 of 901 (3.3%) affected individuals but only 21 of 2,804 (0.7%) controls (odds ratio (OR) = 4.6; confidence interval (CI) = 2.6-8.0; P = 1.3 x 10(-7)). A replication study identified these two variants in 10 of 348 (2.9%) individuals with alcoholic chronic pancreatitis but only 3 of 432 (0.7%) subjects with alcoholic liver disease (OR = 4.2; CI = 1.2-15.5; P = 0.02). CTRC variants were also found in 10 of 71 (14.1%) Indian subjects with tropical pancreatitis but only 1 of 84 (1.2%) healthy controls (OR = 13.6; CI = 1.7-109.2; P = 0.0028). Functional analysis of the CTRC variants showed impaired activity and/or reduced secretion. The results indicate that loss-of-function alterations in CTRC predispose to pancreatitis by diminishing its protective trypsin-degrading activity.

Topics: Cell Line; Chymotrypsin; Germany; Humans; Models, Molecular; Molecular Sequence Data; Mutation; Pancreatitis, Alcoholic; Pancreatitis, Chronic

Chronic pancreatitis (CP) is characterized by intractable abdominal pain, and pancreatic exocrine and endocrine dysfunction. This study investigated whether early surgical drainage of pancreatic duct obstruction leads to improved recovery of pancreatic function compared with late surgical drainage in an experimental model of chronic obstructive pancreatitis.. Twenty-one piglets underwent pancreatic duct ligation and subsequent longitudinal pancreaticojejunostomy after 3 weeks (early drainage) or 6 weeks (late drainage), and drainage continued for 6 weeks. In controls with CP pancreatic duct ligation was continued for 12 weeks without a drainage procedure.. Histological pancreatitis scores decreased with early drainage (P = 0.005), but not with late drainage. Pancreatic secretion of amylase and lipase was restored after early but not late drainage (P = 0.003 and P = 0.048 respectively). Excretion levels of lipase were restored to near-baseline preligation levels after early drainage. Pancreatic endocrine function (glucose tolerance test) showed no insufficiency in either group.. In this model of early versus late surgical drainage of obstructive pancreatitis, histology grades and pancreatic exocrine function showed improvement in the early drainage group but no recovery in the late drainage group.

Topics: Amylases; Animals; Blood Glucose; Chronic Disease; Chymotrypsin; Constriction, Pathologic; Drainage; Feces; Female; Ligation; Lipase; Models, Animal; Pancreaticojejunostomy; Pancreatitis, Chronic; Pressure; Swine; Time Factors

Leptin alters pancreatic exocrine and beta-cell secretion in animal studies. We hypothesized that leptin might be important in the pathogenesis of idiopathic chronic pancreatitis (ICP) and/or the development of diabetes in ICP.. Fifty patients with ICP (25 with diabetes, 25 without diabetes) and 25 healthy controls were included in a prospective, case-control study. Fasting plasma leptin concentration was measured by enzyme-linked immunosorbent assay. Exocrine and endocrine pancreatic functions were assessed by fecal chymotrypsin and serum C-peptide, respectively. Anthropometric parameters and body fat mass (FM) were measured.. Patients with ICP (mean age, 30 years; 33 men) had significantly lower body mass index (19.5 +/- 2.6 kg/m2) and FM (10.6 +/- 4.2 kg) as compared with controls (body mass index, 21.7 +/- 4.1 kg/m2; FM, 19.0 +/- 16.6 kg; P < 0.01). Fecal chymotrypsin (median, 5.2 [range, 0.3-42.6] U/kg) and C-peptide (median, 1.7 [range, 0.2-9.5] ng/mL) were significantly lower in patients than in controls (12.9 [range, 2.5-33.0] U/kg and 3.5 [range, 0.3-10.3] ng/mL; P < 0.01). Plasma leptin concentration was slightly lower but statistically insignificant in patients with ICP (median, 4.0 [range, 2.0-62.5] ng/mL) as compared with controls (median, 5.0 [range, 2.0-63.0] ng/mL). Patients with and those without diabetes were also comparable with regard to their leptin concentration, pancreatic functions, and anthropometric parameters.. Leptin does not seem to have a pathophysiological role in either ICP or the development of diabetes in ICP.

Topics: Adipose Tissue; Adult; Anthropometry; C-Peptide; Case-Control Studies; Chymotrypsin; Diabetes Mellitus, Type 2; Feces; Female; Humans; Leptin; Male; Middle Aged; Pancreas, Exocrine; Pancreatitis, Chronic; Prospective Studies