Localization and pathogenic role of the cysteine protease dentipain in Treponema denticola.

The Msp protein complex and the serine protease dentilisin are the best-characterized virulence factors in Treponema denticola, the major etiological agent of chronic periodontitis. In addition to these outer sheath factors, the cysteine protease dentipain contributes to pathogenicity, but its secretion, processing, cellular localization, and role in T. denticola virulence are not fully understood. In this study, we found that full-sized dentipain (74-kDa) and the 52-kDa truncated form of the enzyme are located, respectively, in the outer sheath derived from T. denticola dentilisin- and the Msp-deficient mutants. Furthermore, dentipain was barely detected in the wild-type strain. These results suggest that dentilisin and Msp, the major outer sheath proteins, are involved in the secretion and maturation of dentipain. Inactivation of the dentipain gene slowed the growth of T. denticola, and the effect was more profound in serum-free medium than in serum-containing medium. Several genes, including those encoding transporters and methyl-accepting chemotaxis proteins, were differentially expressed in the dentipain-deficient mutant. Furthermore, the mutant strain was more hydrophobic than the wild-type strain. Finally, the mutant showed less autoaggregation activity and adhesion to IgG in a serum-free medium than the wild-type strain. These findings suggest that dentipain contributes to the virulence of T. denticola by facilitating adhesion and acquisition of nutrients essential for colonization and proliferation in the gingival crevice under serum-rich conditions.

Arg236 in human chymotrypsin B2 (CTRB2) is a key determinant of high enzyme activity, trypsinogen degradation capacity, and protection against pancreatitis.

Pancreatic chymotrypsins (CTRs) are digestive proteases that in humans include CTRB1, CTRB2, CTRC, and CTRL. The highly similar CTRB1 and CTRB2 are the products of gene duplication. A common inversion at the CTRB1-CTRB2 locus reverses the expression ratio of these isoforms in favor of CTRB2. Carriers of the inversion allele are protected against the inflammatory disorder pancreatitis presumably via their increased capacity for CTRB2-mediated degradation of harmful trypsinogen. To reveal the protective molecular determinants of CTRB2, we compared enzymatic properties of CTRB1, CTRB2, and bovine CTRA (bCTRA). By evolving substrate-like Schistocerca gregaria proteinase inhibitor 2 (SGPI-2) inhibitory loop variants against the chymotrypsins, we found that the substrate binding groove of the three enzymes had overlapping specificities. Based on the selected sequences, we produced eight SGPI-2 variants. Remarkably, CTRB2 and bCTRA bound these inhibitors with significantly higher affinity than CTRB1. Moreover, digestion of peptide substrates, beta casein, and human anionic trypsinogen unequivocally confirmed that CTRB2 is a generally better enzyme than CTRB1 while the potency of bCTRA lies between those of the human isoforms. Unexpectedly, mutation D236R alone converted CTRB1 to a CTRB2-like high activity protease. Modeling indicated that in CTRB1 Met210 partially obstructed the substrate binding groove, which was relieved by the D236R mutation. Taken together, we identify CTRB2 Arg236 as a key positive determinant, while CTRB1 Asp236 as a negative determinant for chymotrypsin activity. These findings strongly support the concept that in carriers of the CTRB1-CTRB2 inversion allele, the superior trypsinogen degradation capacity of CTRB2 protects against pancreatitis.

A 584 bp deletion in CTRB2 inhibits chymotrypsin B2 activity and secretion and confers risk of pancreatic cancer.

Genome-wide association studies (GWASs) have discovered 20 risk loci in the human genome where germline variants associate with risk of pancreatic ductal adenocarcinoma (PDAC) in populations of European ancestry. Here, we fine-mapped one such locus on chr16q23.1 (rs72802365, p = 2.51 × 10-17, OR = 1.36, 95% CI = 1.31-1.40) and identified colocalization (PP = 0.87) with aberrant exon 5-7 CTRB2 splicing in pancreatic tissues (pGTEx = 1.40 × 10-69, ßGTEx = 1.99; pLTG = 1.02 × 10-30, ßLTG = 1.99). Imputation of a 584 bp structural variant overlapping exon 6 of CTRB2 into the GWAS datasets resulted in a highly significant association with pancreatic cancer risk (p = 2.83 × 10-16, OR = 1.36, 95% CI = 1.31-1.42), indicating that it may underlie this signal. Exon skipping attributable to the deletion (risk) allele introduces a premature stop codon in exon 7 of CTRB2, yielding a truncated chymotrypsinogen B2 protein that lacks chymotrypsin activity, is poorly secreted, and accumulates intracellularly in the endoplasmic reticulum (ER). We propose that intracellular accumulation of a nonfunctional chymotrypsinogen B2 protein leads to ER stress and pancreatic inflammation, which may explain the increased pancreatic cancer risk in carriers of CTRB2 exon 6 deletion alleles.

Mouse model suggests limited role for human mesotrypsin in pancreatitis.

Mesotrypsin is a low-abundance human trypsin isoform with a unique evolutionary mutation that conferred resistance to trypsin inhibitors and restricted substrate specificity. Mesotrypsin degrades the serine protease inhibitor Kazal type 1 (SPINK1) and thereby might increase risk for pancreatitis. Here, we report a mouse model designed to test the role of mesotrypsin in pancreatitis. We introduced the human mesotrypsin evolutionary signature mutation into mouse cationic trypsinogen (isoform T7), resulting in a Gly to Arg change at the corresponding position 199. In biochemical experiments using purified proteins, the p.G199R T7 mutant recapitulated all salient features of human mesotrypsin. T7G199R mice developed normally with no spontaneous pancreatitis or other obvious phenotypic changes. Cerulein-induced acute pancreatitis in C57BL/6N and T7G199R mice showed similar severity with respect to inflammatory parameters and acinar cell necrosis while plasma amylase activity was higher in T7G199R mice. Neither SPINK1 degradation nor elevated intrapancreatic trypsin activation was apparent in T7G199R mice. The results indicate that in T7G199R mice the newly created mesotrypsin-like activity has no significant impact on cerulein-induced pancreatitis. The observations suggest that human mesotrypsin is unimportant for pancreatitis; a notion that is consistent with published human genetic studies.

Role of digestive protease enzymes and related genes in host plant adaptation of a polyphagous pest, Spodoptera frugiperda.

The evolutionary success of phytophagous insects depends on their ability to efficiently exploit plants as a source of energy for survival. Herbivorous insects largely depend on the efficiency, flexibility, and diversity of their digestive physiology and sophistication of their detoxification system to use chemically diverse host plants as food sources. The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a polyphagous pest of many commercially important crops. To elucidate the ability of this insect pest to adapt to host plant mechanisms, we evaluated the impact of primary (corn) and alternate (rice) host plants after 11 generations on gut digestive enzymatic activity and expression profiles of related genes. Results indicated that the total protease and class-specific trypsin- and chymotrypsin-like protease activity of S. frugiperda significantly differed among host plant treatments. The class-specific protease profiles greatly differed in S. frugiperda midguts upon larval exposure to different treatments with inhibitors compared with treatments without inhibitors. Similarly, the single and cumulative effects of the enzyme-specific inhibitors TLCK, TPCK, and E-64 significantly increased larval mortality and reduced larval growth/mass across different plant treatments. Furthermore, the quantitative reverse transcription polymerase chain reaction results revealed increased transcription of two trypsin (SfTry-3, SfTry-7) and one chymotrypsin gene (Sfchym-9), which indicated that they have roles in host plant adaptation. Knockdown of these genes resulted in significantly reduced mRNA expression levels of the trypsin genes. This was related to the increased mortality observed in treatments compared with the dsRED control. This result indicates possible roles of S. frugiperda gut digestive enzymes and related genes in host plant adaptation.

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.

Diabetes of the Exocrine Pancreas Related to Hereditary Pancreatitis, an Update.

PURPOSE OF REVIEW: The aim was to review evidence about diabetes secondary to hereditary pancreatitis, seeking novel diagnostic and treatment features. RECENT FINDINGS: 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.

Expression and purification of recombinant human serpin B1 yields novel molecules with altered protease inhibitory activities: Functional implications.

Serpin B1 regulates the innate immune system by inhibiting serine and cysteine proteases that control programmed cell death and proliferation pathways. To provide recombinant human proteins for in vitro and in vivo studies we expressed and purified wild-type human serpin B1 and a C344A variant in the yeast S. cerevisiae. Both proteins expressed well and inhibited elastase and chymotrypsin. However, purification of wild-type serpin B1 in the absence of a reducing agent resulted in the specific loss of elastase - but not chymotrypsin - inhibition, concomitant with the formation of two higher molecular weight forms of the protein - a modified monomer and a dimer created via an intermolecular disulfide bond formed between C344 in respective serpin B1 monomers. In contrast to fully reduced serpin B1, both modified forms were good elastase substrates and catalytically cleaved at multiple adjacent sites within the reactive site loop. In contrast, purification of the C344A variant in the absence of a reducing agent yielded only one form of the protein which retained elastase and chymotrypsin inhibitory properties when purified. Furthermore, the elastase inhibitory activity of wild-type serpin B1, but not the C344A variant, was sensitive to oxidation. Thus, wild-type human serpin B1 should be formulated with a pharmaceutically acceptable reducing agent to protect C344 against post-translational oxidative modifications. Alternatively, the C344A variant of this protein may prove to be a suitable drug development candidate. These findings also suggest that inactivation of serpin B1 by oxidation may have a physiological role to play during inflammation.

Characterization of a chymotrypsin-like enzyme from Trichinella spiralis and its facilitation of larva penetration into the host's enteral epithelial cells.

The aim of this work was to identify the molecular characteristics of a chymotrypsin-like enzyme from Trichinella spiralis (Tschy) and its facilitation of larval penetration into enteral epithelial cells (EECs). The complete Tschy cDNA sequence was cloned and expressed in Escherichia coli BL21. RT-PCR, IIFA and western blotting showed that Tschy was expressed at the T. spiralis muscle larvae (ML), intestinal infective L1 larvae (IL1), adult worms (AW) and embryo stages and was primarily located in the stichosome of this parasite. The results of ELISA, IIFA and Far-western assays showed that there was a specific binding between rTschy and EECs, and the binding was dependent on the dose of both rTschy and EEC proteins. Confocal microscopy demonstrated that the binding was located in the EEC cytoplasm. rTschy facilitated T. spiralis larval penetration of EECs, and anti-rTschy antibodies impeded the larval intrusion of EECs. These results demonstrate that Tschy facilitated the larval intrusion of the host's enteral epithelium and could be a candidate molecular target for vaccine against the enteral invasive phase of T. spiralis.

Chronic pancreatitis with polycystic kidney disease: A rare coincidence?

INTRODUCTION: In children, chronic pancreatitis (CP) is usually associated with anatomical anomalies of the pancreas and biliary tract or is genetically determined. Autosomal dominant polycystic kidney disease (ADPKD) may present with extrarenal cyst formation, sometimes involving the pancreas. Large enough, these cysts may cause pancreatitis in ADPKD patients. CASE PRESENTATION: Herein, we present a case of a 12-year-old Caucasian girl with recurrent pancreatitis with no identifiable traumatic, metabolic, infectious, drug, or immunologic causes. Structural anomalies of the pancreas, including cysts, were ruled out by imaging. However, bilateral cystic kidneys were found as an incidental finding. Her family history was negative for pancreatitis, but positive for polycystic kidney disease. Molecular analysis of ADPKD-causing mutations revealed a novel c.9659C>A (p.Ser3220*) mutation in the PKD1 gene confirming the clinical suspicion of ADPKD. Although CP may rarely occur as an extrarenal manifestation of ADPKD with pancreatic cysts, it is unusual in their absence. Thus, molecular analysis of pancreatitis susceptibility genes was performed and a homozygous pathologic c.180C>T (p.G60=) variant of the CTRC gene, known to increase the risk of CP, was confirmed. CONCLUSION: This is the first reported case of a pediatric patient with coincidence of genetically determined CP and ADPKD. Occurrence of pancreatitis in children with ADPKD without pancreatic cysts warrants further investigation of CP causing mutations.

Tumour response to TRK inhibition in a patient with pancreatic adenocarcinoma harbouring an NTRK gene fusion.

BACKGROUND: Although rare, NTRK gene fusions are known to be oncogenic drivers in pancreatic ductal adenocarcinoma (PDAC). We report the response of a metastatic CTRC-NTRK1 gene fusion-positive PDAC to targeted treatment with the oral tropomyosin receptor kinase (TRK) inhibitor larotrectinib and the eventual development of resistance to treatment. PATIENT, METHODS AND RESULTS: A 61-year-old woman presented with a 2.5-cm mass in the body of the pancreas and a 1.2-cm liver lesion on routine follow-up for endometrial cancer that was in complete remission. Liver biopsy confirmed a primary PDAC unrelated to the endometrial cancer. The patient was treated with gemcitabine, nab-paclitaxel and ADI-PEG 20 for 12 months until disease progression and toxicity emerged [best overall response (BOR): partial response (PR)]. The patient switched to a modified regimen of folinic acid, fluorouracil, irinotecan and oxaliplatin for 4 months until neuropathy occurred. Oxaliplatin was withheld until disease progression 6 months later (BOR: stable disease). Despite recommencing oxaliplatin, the disease continued to progress. At this time, somatic profiling of the liver lesion revealed a CTRC-NTRK1 gene fusion. Treatment with larotrectinib 100 mg twice daily was commenced with BOR of PR at 2 months. The patient progressed after 6 months and was re-biopsied. Treatment was switched to the investigational next-generation TRK inhibitor selitrectinib (BAY 2731954, LOXO-195) 100 mg twice daily. After 2 months, the disease progressed and dabrafenibtrametinib combination therapy was initiated due to existence of a BRAF-V600E mutation. However, the cancer continued to progress and the patient died 2 months later. CONCLUSIONS: Targeted TRK inhibition with larotrectinib in PDAC harbouring a CTRC-NTRK1 gene fusion is well tolerated and can improve quality of life for the patient. However, acquired resistance to therapy can emerge in some patients. Next-generation TRK inhibitors such as selitrectinib are currently in development to overcome this resistance (NCT02576431; NCT03215511).

Structural comparison strengthens the higher-order classification of proteases related to chymotrypsin.

Specific cleavage of proteins by proteases is essential for several cellular, physiological, and viral processes. Chymotrypsin-related proteases that form the PA clan in the MEROPS classification of proteases is one of the largest and most diverse group of proteases. The PA clan comprises serine proteases from bacteria, eukaryotes, archaea, and viruses and chymotrypsin-related cysteine proteases from positive-strand RNA viruses. Despite low amino acid sequence identity, all PA clan proteases share a conserved double ß-barrel structure. Using an automated structure-based hierarchical clustering method, we identified a common structural core of 72 amino acid residues for 143 PA clan proteases that represent 12 protein families and 11 subfamilies. The identified core is located around the catalytic site between the two ß-barrels and resembles the structures of the smallest PA clan proteases. We constructed a structure-based distance tree derived from the properties of the identified common core. Our structure-based analyses support the current classification of these proteases at the subfamily level and largely at the family level. Structural alignment and structure-based distance trees could thus be used for directing objective classification of PA clan proteases and to strengthen their higher order classification. Our results also indicate that the PA clan proteases of positive-strand RNA viruses are related to cellular heat-shock proteases, which suggests that the exchange of protease genes between viruses and cells might have occurred more than once.

Do CTRC mutations affect the development of alcoholic chronic pancreatitis and its course among Poles: Preliminary study.

BACKGROUND: Genetic mutations are one of the etiological factors that predispose people to develop chronic pancreatitis. OBJECTIVES: 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. MATERIAL AND METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.

SPINK1, PRSS1, CTRC, and CFTR Genotypes Influence Disease Onset and Clinical Outcomes in Chronic Pancreatitis.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Prevalence of abnormal glucose metabolism in pediatric acute, acute recurrent and chronic pancreatitis.

Type 3C Diabetes, or diseases of the exocrine pancreas has been reported to occur in approximately 30% of adult patient with pancreatitis. The incidence of glucose abnormalities or risk factors that may predict the development of abnormal glucose in the pediatric pancreatitis population is not known. We performed a retrospective chart review from 1998-2016 for patients who carry the diagnosis of acute pancreatitis (AP), acute recurrent pancreatitis (ARP), and chronic pancreatitis (CP). We extracted glucose values, HbA1c%, and data from oral glucose tolerance and mixed meal testing with timing in relation to pancreatic exacerbations. Patient characteristic data such as age, gender, body proportions, family history of pancreatitis, exocrine function and genetic mutations were also assessed. Abnormal glucose was based on definitions put forth by the American Diabetes Society for pre-diabetes and diabetes. Fifty-two patients had AP and met criteria. Of those, 15 (29%) had glucose testing on or after the first attack, 21 (40%) were tested on or after the second attack (in ARP patients) and 16 (31%) were tested after a diagnosis of CP. Of the patients tested for glucose abnormalities, 25% (13/52) had abnormal glucose testing (testing indicating pre-DM or DM as defined by ADA guidelines. A significantly higher proportion of the abnormal glucose testing was seen in patients (85%, 11/13) with a BMI at or greater than the 85th percentile compared to the normal glucose patients (28%, 11/39) (p = 0.0007). A significantly higher proportion of the abnormal glucose patients (77%, 10/13) had SAP during the prior AP episode to testing compared to the 10% (4/39) of the normal glucose patients (p<0.0001). Older age at DM testing was associated with a higher prevalence of abnormal glucose testing (p = 0.04). In our patient population, a higher proportion of glucose abnormalities were after the second episode of pancreatitis, however 62% (8/13) with abnormalities was their first time tested. We identified obesity and having severe acute pancreatitis (SAP) during the prior AP episode to testing could be associated with abnormal glucose. We propose that systematic screening for abnormal glucose after the first episode of acute pancreatitis in order to better establish the timing of diabetes progression.

The Role of Genetics in Pancreatitis.

Individuals with acute recurrent and chronic pancreatitis may have an inherited predisposition to the development of the disease. Pancreatitis in the setting of a significant family history of the disease can be classified as hereditary or familial pancreatitis. In this article, the authors closely examine the specific genes implicated in pancreatitis, investigate the role of genetic testing for diagnosis, and describe the impact of genetic testing results on clinical management.

Functional and association analysis of an Amerindian-derived population-specific p.(Thr280Met) variant in RBPJL, a component of the PTF1 complex.

PTF1 complex is critical for pancreatic development and maintenance of adult exocrine pancreas. As a part of our ongoing studies to identify genetic variation that contributes to type 2 diabetes (T2D) in American Indians, we analyzed variation in genes that form this complex, namely PTF1A, RBPJ, and its paralogue RBPJL. A c.839C>T (p.(Thr280Met)) variant (rs200998587:C>T, risk allele frequency = 0.03) in RBPJL, identified only in Amerindian-derived populations, associated with T2D (OR = 1.60[1.21-2.13] per Met allele, P = 0.001) and age of diabetes onset (HR = 1.40[1.14-1.72], P = 0.001). Knockdown of Rbpjl in mouse pancreatic acinar cells resulted in a significant decrease in the mRNA expression of genes encoding exocrine enzymes including Ctrb. CTRB1/2 is an established T2D locus where the protective allele associates with increased GLP-1-stimulated insulin secretion and higher expression of CTRB1/2. In vitro studies show that cells expressing the Met280 allele had lower RBPJL protein levels than cells expressing the Thr280 allele, despite having comparable levels of RNA, suggesting that the Met280 RBPJL is less stable. Additionally, luciferase assays in HEK293 cells which examined two different RBPJL responsive promoters, including the promoter for CTRB1, also identified reduced transactivation by the Met280 RBPJL. Similarly, overexpression of both Met280 and Thr280 RBPJL in mouse pancreatic acinar cells identified a significant impairment in the expression of Cel when transactivated by the Met280 RBPJL. In summary, we identified a functional, Amerindian-derived population-specific c.839C>T (p.(Thr280Met)) variant in the pancreas specific RBPJL that may modify T2D risk by regulating exocrine enzyme expression.

CTRC gene polymorphism may increase pancreatic cancer risk - preliminary study.

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

Early-Onset Acute Recurrent and Chronic Pancreatitis Is Associated with PRSS1 or CTRC Gene Mutations.

OBJECTIVES: 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). STUDY DESIGN: 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). RESULTS: 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). CONCLUSIONS: 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.

An Evaluation of Factors Associated With Pathogenic PRSS1, SPINK1, CTFR, and/or CTRC Genetic Variants in Patients With Idiopathic Pancreatitis.

OBJECTIVES: We evaluated factors associated with pathogenic genetic variants in patients with idiopathic pancreatitis. METHODS: Genetic testing (PRSS1, CFTR, SPINK1, and CTRC) was performed in all eligible patients with idiopathic pancreatitis between 2010 to 2015. Patients were classified into the following groups based on a review of medical records: (1) acute recurrent idiopathic pancreatitis (ARIP) with or without underlying chronic pancreatitis; (2) idiopathic chronic pancreatitis (ICP) without a history of ARP; (3) an unexplained first episode of acute pancreatitis (AP)<35 years of age; and (4) family history of pancreatitis. Logistic regression analysis was used to determine the factors associated with pathogenic genetic variants. RESULTS: Among 197 ARIP and/or ICP patients evaluated from 2010 to 2015, 134 underwent genetic testing. A total of 88 pathogenic genetic variants were found in 64 (47.8%) patients. Pathogenic genetic variants were identified in 58, 63, and 27% of patients with ARIP, an unexplained first episode of AP <35 years of age, and ICP without ARP, respectively. ARIP (OR: 18.12; 95% CI: 2.16-151.87; P=0.008) and an unexplained first episode of AP<35 years of age (OR: 2.46; 95% CI: 1.18-5.15; P=0.017), but not ICP, were independently associated with pathogenic genetic variants in the adjusted analysis. CONCLUSIONS: Pathogenic genetic variants are most likely to be identified in patients with ARIP and an unexplained first episode of AP<35 years of age. Genetic testing in these patient populations may delineate an etiology and prevent unnecessary diagnostic testing and procedures.