Notch1 Induces Defective Epithelial Surfactant Processing and Pulmonary Fibrosis.

Rationale: Although type II alveolar epithelial cells (AEC2s) are chronically injured in idiopathic pulmonary fibrosis (IPF), they contribute to epithelial regeneration in IPF. Objectives: We hypothesized that Notch signaling may contribute to AEC2 proliferation, dedifferentiation characterized by loss of surfactant processing machinery, and lung fibrosis in IPF. Methods: We applied microarray analysis, kinome profiling, flow cytometry, immunofluorescence analysis, western blotting, quantitative PCR, and proliferation and surface activity analysis to study epithelial differentiation, proliferation, and matrix deposition in vitro (AEC2 lines, primary murine/human AEC2s), ex vivo (human IPF-derived precision-cut lung slices), and in vivo (bleomycin and pepstatin application, Notch1 [Notch receptor 1] intracellular domain overexpression). Measurements and Main Results: We document here extensive SP-B and -C (surfactant protein-B and -C) processing defects in IPF AEC2s, due to loss of Napsin A, resulting in increased intra-alveolar surface tension and alveolar collapse and induction of endoplasmic reticulum stress in AEC2s. In vivo pharmacological inhibition of Napsin A results in the development of AEC2 injury and overt lung fibrosis. We also demonstrate that Notch1 signaling is already activated early in IPF and determines AEC2 fate by inhibiting differentiation (reduced lamellar body compartment, reduced capacity to process hydrophobic SP) and by causing increased epithelial proliferation and development of lung fibrosis, putatively via altered JAK (Janus kinase)/Stat (signal transducer and activator of transcription) signaling in AEC2s. Conversely, inhibition of Notch signaling in IPF-derived precision-cut lung slices improved the surfactant processing capacity of AEC2s and reversed fibrosis. Conclusions: Notch1 is a central regulator of AEC2 fate in IPF. It induces alveolar epithelial proliferation and loss of Napsin A and of surfactant proprotein processing, and it contributes to fibroproliferation.

Colocalization analysis of pancreas eQTLs with risk loci from alcoholic and novel non-alcoholic chronic pancreatitis GWAS suggests potential disease causing mechanisms.

BACKGROUND: Previous genome-wide association studies (GWAS) identified genome-wide significant risk loci in chronic pancreatitis and investigated underlying disease causing mechanisms by simple overlaps with expression quantitative trait loci (eQTLs), a procedure which may often result in false positive conclusions. METHODS: We conducted a GWAS in 584 non-alcoholic chronic pancreatitis (NACP) patients and 6040 healthy controls. Next, we applied Bayesian colocalization analysis of identified genome-wide significant risk loci from both, our recently published alcoholic chronic pancreatitis (ACP) and the novel NACP dataset, with pancreas eQTLs from the GTEx V8 European cohort to prioritize candidate causal genes and extracted credible sets of shared causal variants. RESULTS: Variants at the CTRC (p = 1.22 × 10-21) and SPINK1 (p = 6.59 × 10-47) risk loci reached genome-wide significance in NACP. CTRC risk variants colocalized with CTRC eQTLs in ACP (PP4 = 0.99, PP4/PP3 = 95.51) and NACP (PP4 = 0.99, PP4/PP3 = 95.46). For both diseases, the 95% credible set of shared causal variants consisted of rs497078 and rs545634. CLDN2-MORC4 risk variants colocalized with CLDN2 eQTLs in ACP (PP4 = 0.98, PP4/PP3 = 42.20) and NACP (PP4 = 0.67, PP4/PP3 = 7.18), probably driven by the shared causal variant rs12688220. CONCLUSIONS: A shared causal CTRC risk variant might unfold its pathogenic effect in ACP and NACP by reducing CTRC expression, while the CLDN2-MORC4 shared causal variant rs12688220 may modify ACP and NACP risk by increasing CLDN2 expression.

Genetic Analysis of the ATG16L1 c.898A>G (p.T300A) Variant in Acute and Chronic Pancreatitis.

OBJECTIVES: Human and animal studies suggest an important role of autophagy in the pathogenesis of pancreatitis. ATG16L1 (autophagy-related 16 like 1) is part of a protein complex that is involved in the formation of autophagosomes. The c.898A > G (p.T300A) variant of ATG16L1 is associated with Crohn disease. In this study, we analyzed ATG16L1 c.898A > G (p.T300A) for an association with pancreatitis. METHODS: We genotyped 777 patients and 551 control subjects of German origin by melting curve analysis using fluorescence resonance energy transfer probes. The patient group included 429 patients with nonalcoholic chronic pancreatitis (CP), 141 patients with alcoholic CP, and 207 patients with acute pancreatitis (AP). We classified AP by severity according to the Atlanta symposium 1992. RESULTS: Allele and genotype frequencies of ATG16L1 c.898A > G (p.T300A) did not differ significantly between patients and controls (G allele frequencies: nonalcoholic CP, 49.9%; alcoholic CP, 48.2%; AP, 49.5%; controls, 52.7%). We found no significant association with the severity of AP either. CONCLUSIONS: Our data do not support a role of ATG16L1 c.898A > G (p.T300A) in the pathogenesis of AP or CP or an influence on the severity of AP.

Loss of function TRPV6 variants are associated with chronic pancreatitis in nonalcoholic early-onset Polish and German patients.

PURPOSE: Loss of function variants of the transient receptor potential cation channel, subfamily V, member 6 (TRPV6) have been recently associated with chronic pancreatitis (CP) in Japanese, German and French patients. Here, we investigated the association of TRPV6 variants with CP in independent European cohorts of early-onset CP patients from Poland and Germany. PATIENTS AND METHODS: We enrolled 152 pediatric CP patients (median age 8.6 yrs) with no history of alcohol/smoking abuse and 472 controls from Poland as well as 157 nonalcoholic young CP patients (median age 20 yrs) and 750 controls from Germany. Coding regions of TRPV6 were screened by Sanger and next generation sequencing. Selected, potentially pathogenic TRPV6 variants were expressed in HEK293T cells and TRPV6 activity was analyzed using ratiometric Ca2+ measurements. RESULTS: Overall, we identified 10 novel (3 nonsense and 7 missenses) TRPV6 variants in CP patients. TRPV6 p.V239SfsX53 nonsense variant and the variants showing significant decrease in intracellular Ca2+ concentration in HEK293T cells (p.R174X, p.L576R, p.R342Q), were significantly overrepresented in Polish patients as compared to controls (6/152, 3.9% vs. 0/358, 0%; P = 0,0007). Nonsense TRPV6 variants predicted as loss of function (p.V239SfsX53 and p.R624X) were also significantly overrepresented in German patients (3/157; 2.0% vs 0/750; 0%, P = 0.005). CONCLUSIONS: We showed that TRPV6 loss of function variants are associated with elevated CP risk in early-onset Polish and German patients confirming that TRPV6 is a novel CP susceptibility gene.

European Guideline on IgG4-related digestive disease - UEG and SGF evidence-based recommendations.

The overall objective of these guidelines is to provide evidence-based recommendations for the diagnosis and management of immunoglobulin G4 (IgG4)-related digestive disease in adults and children. IgG4-related digestive disease can be diagnosed only with a comprehensive work-up that includes histology, organ morphology at imaging, serology, search for other organ involvement, and response to glucocorticoid treatment. Indications for treatment are symptomatic patients with obstructive jaundice, abdominal pain, posterior pancreatic pain, and involvement of extra-pancreatic digestive organs, including IgG4-related cholangitis. Treatment with glucocorticoids should be weight-based and initiated at a dose of 0.6-0.8 mg/kg body weight/day orally (typical starting dose 30-40 mg/day prednisone equivalent) for 1 month to induce remission and then be tapered within two additional months. Response to initial treatment should be assessed at week 2-4 with clinical, biochemical and morphological markers. Maintenance treatment with glucocorticoids should be considered in multi-organ disease or history of relapse. If there is no change in disease activity and burden within 3 months, the diagnosis should be reconsidered. If the disease relapsed during the 3 months of treatment, immunosuppressive drugs should be added.

IRF5 Is Required for Bacterial Clearance in Human M1-Polarized Macrophages, and IRF5 Immune-Mediated Disease Risk Variants Modulate This Outcome.

Common IFN regulatory factor 5 (IRF5) variants associated with multiple immune-mediated diseases are a major determinant of interindividual variability in pattern recognition receptor (PRR)-induced cytokines in macrophages. PRR-initiated pathways also contribute to bacterial clearance, and dysregulation of bacterial clearance can contribute to immune-mediated diseases. However, the role of IRF5 in macrophage-mediated bacterial clearance is not well defined. Furthermore, it is unclear if macrophages from individuals who are carriers of low IRF5-expressing genetic variants associated with protection for immune-mediated diseases might be at a disadvantage in bacterial clearance. We found that IRF5 was required for optimal bacterial clearance in PRR-stimulated, M1-differentiated human macrophages. Mechanisms regulated by IRF5 included inducing reactive oxygen species through p40phox, p47phox and p67phox, NOS2, and autophagy through ATG5. Complementing these pathways in IRF5-deficient M1 macrophages restored bacterial clearance. Further, these antimicrobial pathways required the activation of IRF5-dependent MAPK, NF-κB, and Akt2 pathways. Importantly, relative to high IRF5-expressing rs2004640/rs2280714 TT/TT immune-mediated disease risk-carrier human macrophages, M1-differentiated GG/CC carrier macrophages demonstrated less reactive oxygen species, NOS2, and autophagy pathway induction and, consequently, reduced bacterial clearance. Increasing IRF5 expression to the rs2004640/rs2280714 TT/TT levels restored these antimicrobial pathways. We define mechanisms wherein common IRF5 genetic variants modulate bacterial clearance, thereby highlighting that immune-mediated disease risk IRF5 carriers might be relatively protected from microbial-associated diseases.

United European Gastroenterology evidence-based guidelines for the diagnosis and therapy of chronic pancreatitis (HaPanEU).

BACKGROUND: There have been substantial improvements in the management of chronic pancreatitis, leading to the publication of several national guidelines during recent years. In collaboration with United European Gastroenterology, the working group on 'Harmonizing diagnosis and treatment of chronic pancreatitis across Europe' (HaPanEU) developed these European guidelines using an evidence-based approach. METHODS: Twelve multidisciplinary review groups performed systematic literature reviews to answer 101 predefined clinical questions. Recommendations were graded using the Grading of Recommendations Assessment, Development and Evaluation system and the answers were assessed by the entire group in a Delphi process online. The review groups presented their recommendations during the 2015 annual meeting of United European Gastroenterology. At this one-day, interactive conference, relevant remarks were voiced and overall agreement on each recommendation was quantified using plenary voting (Test and Evaluation Directorate). After a final round of adjustments based on these comments, a draft version was sent out to external reviewers. RESULTS: The 101 recommendations covered 12 topics related to the clinical management of chronic pancreatitis: aetiology (working party (WP)1), diagnosis of chronic pancreatitis with imaging (WP2 and WP3), diagnosis of pancreatic exocrine insufficiency (WP4), surgery in chronic pancreatitis (WP5), medical therapy (WP6), endoscopic therapy (WP7), treatment of pancreatic pseudocysts (WP8), pancreatic pain (WP9), nutrition and malnutrition (WP10), diabetes mellitus (WP11) and the natural course of the disease and quality of life (WP12). Using the Grading of Recommendations Assessment, Development and Evaluation system, 70 of the 101 (70%) recommendations were rated as 'strong' and plenary voting revealed 'strong agreement' for 99 (98%) recommendations. CONCLUSIONS: The 2016 HaPanEU/United European Gastroenterology guidelines provide evidence-based recommendations concerning key aspects of the medical and surgical management of chronic pancreatitis based on current available evidence. These recommendations should serve as a reference standard for existing management of the disease and as a guide for future clinical research.

BCL3 Reduces the Sterile Inflammatory Response in Pancreatic and Biliary Tissues.

BACKGROUND & AIMS: Under conditions of inflammation in the absence of micro-organisms (sterile inflammation), necrotic cells release damage-associated molecular patterns that bind to Toll-like receptors on immune cells to activate a signaling pathway that involves activation of IκB kinase and nuclear factor κB (NF-κB). Little is known about the mechanisms that control NF-κB activity during sterile inflammation. We analyzed the contribution of B-cell CLL/lymphoma 3 (BCL3), a transcription factor that associates with NF-κB, in control of sterile inflammation in the pancreas and biliary system of mice. METHODS: Acute pancreatitis (AP) was induced in C57BL/6 (control) and Bcl3(-/-) mice by intraperitoneal injection of cerulein or pancreatic infusion of sodium taurocholate. We also studied Mdr2(-/-) mice, which develop spontaneous biliary inflammation, as well as Bcl3(-/-)Mdr2(-/-) mice. We performed immunohistochemical analyses of inflamed and noninflamed regions of pancreatic tissue from patients with AP or primary sclerosing cholangitis (PSC), as well as from mice. Immune cells were characterized by fluorescence-activated cell sorting analysis. Control or Bcl3(-/-) mice were irradiated, injected with bone marrow from Bcl3(-/-) or control mice, and AP was induced. RESULTS: Pancreatic or biliary tissues from patients with AP or PSC had higher levels of BCL3 and phosphorylated RelA and IκBα in inflamed vs noninflamed regions. Levels of BCL3 were higher in pancreata from control mice given cerulein than from mice without AP, and were higher in biliary tissues from Mdr2(-/-) mice than from control mice. Bcl3(-/-) mice developed more severe AP after administration of cerulein or sodium taurocholate than control mice; pancreata from the Bcl3(-/-) mice with AP had greater numbers of macrophages, myeloid-derived suppressor cells, dendritic cells, and granulocytes than control mice with AP. Activation of NF-κB was significantly prolonged in Bcl3(-/-) mice with AP, compared with control mice with AP. Bcl3(-/-)Mdr2(-/-) mice developed more severe cholestasis and had increased markers of liver injury and increased proliferation of biliary epithelial cells and hepatocytes than Mdr2(-/-) mice. In experiments with bone marrow chimeras, expression of BCL3 by acinar cells, but not myeloid cells, was required for reduction of inflammation during development of AP. BCL3 inhibited ubiquitination and proteasome-mediated degradation of p50 homodimers, which prolonged binding of NF-κB heterodimers to DNA. CONCLUSIONS: BCL3 is up-regulated in inflamed pancreatic or biliary tissues from mice and patients with AP or cholangitis. Its production appears to reduce the inflammatory response in these tissues via blocking ubiquitination and proteasome-mediated degradation of p50 homodimers.

Impaired autophagy induces chronic atrophic pancreatitis in mice via sex- and nutrition-dependent processes.

BACKGROUND & AIMS: Little is known about the mechanisms of the progressive tissue destruction, inflammation, and fibrosis that occur during development of chronic pancreatitis. Autophagy is involved in multiple degenerative and inflammatory diseases, including pancreatitis, and requires the protein autophagy related 5 (ATG5). We created mice with defects in autophagy to determine its role in pancreatitis. METHODS: We created mice with pancreas-specific disruption of Atg5 (Ptf1aCreex1;Atg5F/F mice) and compared them to control mice. Pancreata were collected and histology, immunohistochemistry, transcriptome, and metabolome analyses were performed. ATG5-deficient mice were placed on diets containing 25% palm oil and compared with those on a standard diet. Another set of mice received the antioxidant N-acetylcysteine. Pancreatic tissues were collected from 8 patients with chronic pancreatitis (CP) and compared with pancreata from ATG5-deficient mice. RESULTS: Mice with pancreas-specific disruption of Atg5 developed atrophic CP, independent of ß-cell function; a greater proportion of male mice developed CP than female mice. Pancreata from ATG5-deficient mice had signs of inflammation, necrosis, acinar-to-ductal metaplasia, and acinar-cell hypertrophy; this led to tissue atrophy and degeneration. Based on transcriptome and metabolome analyses, ATG5-deficient mice produced higher levels of reactive oxygen species than control mice, and had insufficient activation of glutamate-dependent metabolism. Pancreata from these mice had reduced autophagy, increased levels of p62, and increases in endoplasmic reticulum stress and mitochondrial damage, compared with tissues from control mice; p62 signaling to Nqo1 and p53 was also activated. Dietary antioxidants, especially in combination with palm oil-derived fatty acids, blocked progression to CP and pancreatic acinar atrophy. Tissues from patients with CP had many histologic similarities to those from ATG5-deficient mice. CONCLUSIONS: Mice with pancreas-specific disruption of Atg5 develop a form of CP similar to that of humans. CP development appears to involve defects in autophagy, glutamate-dependent metabolism, and increased production of reactive oxygen species. These mice might be used to identify therapeutic targets for CP.

Myosin IXb variants and their pivotal role in maintaining the intestinal barrier: a study in Crohn's disease.

BACKGROUND: Myosin IXb (MYO9B) is involved in the regulation of epithelial barrier function. We hypothesized that MYO9B variants are associated with increased intestinal permeability measured in patients with Crohn's disease (CD), where barrier dysfunction is crucially involved in disease development. METHODS: We sequenced MYO9B and genotyped five MYO9B variants (rs1545620, rs1457092, rs2279003, rs2305764 and rs2279002) and correlated these data to measurement of intestinal permeability in German CD patients (n = 122) obtained by standard oral sugar test using the lactulose/mannitol ratio after measurement of urinary excretion. We furthermore studied MYO9B variants in three European cohorts with inflammatory bowel disease (IBD) and healthy controls : Germany (CD = 264; ulcerative colitis = 143 [UC]; HC = 372); Hungary (CD = 147; UC = 117; HC = 195), the Netherlands (CD = 157; HC = 219). RESULTS: We found an association for four studied MYO9B variants to an increased intestinal permeability in CD patients (rs1545620, p = 0.010; rs1457092, p = 0.024; rs2279003, p = 0.003; rs2305764, p = 0.015). Furthermore, we observed significantly higher absolute values of intestinal permeability for individuals carrying risk alleles within MYO9B. Looking for an overall disease association, only the rs2305764 variant was associated with CD in the Dutch cohort (p = 0.004), but not in the German or Hungarian cohort. No association to UC or a distinct phenotype in both CD and UC patients was observed for all studied MYO9B variants. CONCLUSION: Our data suggest a link between MYO9B variants to an increased intestinal permeability in CD patients. This supports the influence of Myosin IXb on the integrity of the epithelial barrier. The role of MYO9B variants in the overall susceptibility to IBD, however, remains to be elucidated.

Colonic expression of the peptide transporter PEPT1 is downregulated during intestinal inflammation and is not required for NOD2-dependent immune activation.

BACKGROUND: PEPT1 was proposed to be expressed only in inflamed colonic tissues in which it could contribute to inflammatory bowel disease (IBD) development by transporting bacterial peptides, such as muramyl dipeptide (MDP), that activate intracellular pattern recognition receptors, such as the nucleotide-binding and oligomerization domain 2. To better define the pathological relevance of this transporter, we analyzed PEPT1 expression during intestinal inflammation and studied the susceptibility of Pept1-deficient (Pept1) mice to experimental colitis. METHODS: Wild-type and Pept1 mice were treated with dextran sulfate sodium and 2,4,6-trinitrobenzene sulfonic acid to induce colitis, and MDP-induced cytokine expression was studied in colonic tissue cultures. PEPT1 expression was characterized in mouse models of Crohn's disease-like ileitis (Tnf) or colitis (Il-10, Il-10XTlr2) and endoscopic tissue samples from descending colon of patients with IBD (n = 11) and controls (n = 17). Moreover, the prevalence of the PEPT1 single-nucleotide polymorphism rs2297322 was tested in German patients with IBD (n = 458) and controls (n = 452). RESULTS: PEPT1 expression was consistently reduced under condition of acute or chronic experimental inflammation. Wild-type and Pept1 mice revealed comparable susceptibility to dextran sulfate sodium-induced and 2,4,6-trinitrobenzene sulfonic acid-induced colitis, and MDP-induced cytokine expression was PEPT1-independent. PEPT1 expression levels were also decreased in descending colon of patients with IBD during acute inflammation, but the rs2297322 single-nucleotide polymorphism was not associated with IBD susceptibility in the German cohort. CONCLUSIONS: PEPT1 expression is reduced during intestinal inflammation and PEPT1 is neither required for MDP-induced immune response nor is the PEPT1 rs2297322 single-nucleotide polymorphism associated with IBD susceptibility in our German cohort. These data strongly argue against a primary role of PEPT1 in the initiation or progression of IBD.

Mutations in the human UBR1 gene and the associated phenotypic spectrum.

Johanson-Blizzard syndrome (JBS) is a rare, autosomal recessive disorder characterized by exocrine pancreatic insufficiency, typical facial features, dental anomalies, hypothyroidism, sensorineural hearing loss, scalp defects, urogenital and anorectal anomalies, short stature, and cognitive impairment of variable degree. This syndrome is caused by a defect of the E3 ubiquitin ligase UBR1, which is part of the proteolytic N-end rule pathway. Herein, we review previously reported (n = 29) and a total of 31 novel UBR1 mutations in relation to the associated phenotype in patients from 50 unrelated families. Mutation types include nonsense, frameshift, splice site, missense, and small in-frame deletions consistent with the hypothesis that loss of UBR1 protein function is the molecular basis of JBS. There is an association of missense mutations and small in-frame deletions with milder physical abnormalities and a normal intellectual capacity, thus suggesting that at least some of these may represent hypomorphic UBR1 alleles. The review of clinical data of a large number of molecularly confirmed JBS cases allows us to define minimal clinical criteria for the diagnosis of JBS. For all previously reported and novel UBR1 mutations together with their clinical data, a mutation database has been established at LOVD.

Functional effects of 13 rare PRSS1 variants presumed to cause chronic pancreatitis.

OBJECTIVE: 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. DESIGN: Here, we investigated the functional phenotype of 13 published PRSS1 variants with respect to autoactivation in the presence of CTRC and cellular secretion. RESULTS: 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. CONCLUSIONS: 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.

Mutational analysis of ATP8B1 in patients with chronic pancreatitis.

BACKGROUND: Mutations in genes encoding cationic trypsinogen (PRSS1), pancreatic secretory trypsin inhibitor (SPINK1) and chymotrypsinogen C (CTRC) are associated with chronic pancreatitis. However, in many patients with a familial chronic pancreatitis pattern suggesting a genetic cause, no mutations in either of these genes can be found, indicating that other, still unknown, associated genes exist. In this respect ATP8B1 is an interesting candidate due to its strong expression in the pancreas, its supposed general function in membrane organization and the higher incidence of pancreatitis in patients with ATP8B1 deficiency. METHODS: We analyzed all 27 ATP8B1 coding exons and adjacent non-coding sequences of 507 chronic pancreatitis patients by direct sequencing. Exons that harbored possible relevant variations were subsequently sequenced in 1,027 healthy controls. RESULTS: In the exonic regions, 5 novel non-synonymous alterations were detected as well as 14 previously described alterations of which some were associated with ATP8B1 deficiency. However, allele frequencies for any of these variations did not significantly differ between patients and controls. Furthermore, several non-synonymous variants were exclusively detected in control subjects and multiple variants in the non-coding sequence were identified with similar frequencies in both groups. CONCLUSIONS: We did not find an association between heterozygous ATP8B1 variants and chronic pancreatitis in our cohort of patients with hereditary and idiopathic chronic pancreatitis.

Chronic pancreatitis--definition, etiology, investigation and treatment.

BACKGROUND: Chronic pancreatitis has an annual incidence of 23 per 100 000 population in Germany, where it accounts for about 10 000 hospital admissions per year. The disease shortens the life expectancy of its sufferers by an average of 23%. It most commonly affects men aged 20 to 40. METHODS: A systematic search for pertinent literature retrieved 19 569 publications, 485 of which were considered in the creation of this guideline, including 67 randomized controlled trials (RCTs). A consensus conference reached agreement on a total of 156 definitions and recommendations. RESULTS: The identification of genetic risk factors for pancreatitis is now well established. The diagnosis is made mainly with ultrasonography of the pancreas; if the findings are uncertain, further studies can be performed, including endosonography and endosonographically assisted fine-needle puncture for the examination of small foci of disease. Computed tomography and MRI/magnetic resonance cholangiopancreatography are supplementary diagnostic methods. Endoscopic retrograde cholangiopancreatography is now used almost exclusively for treatment, rather than for diagnosis. 30% to 60% of patients develop complications of chronic pancreatitis, including pseudocysts, bile-duct stenosis, or medically intractable pain, which can be treated with an endoscopic or surgical intervention. Patients with steatorrhea, a pathological pancreatic function test, or clinical evidence of malabsorption should be given pancreatin supplementation. The head of the pancreas should be resected if it contains an inflammatory pseudotumor. CONCLUSION: The management of patients with chronic pancreatitis requires close interdisciplinary collaboration, as it can be treated medically and endoscopically as well as surgically.

CFTR, SPINK1, CTRC and PRSS1 variants in chronic pancreatitis: is the role of mutated CFTR overestimated?

OBJECTIVE: 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. DESIGN: 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. RESULTS: 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). CONCLUSIONS: 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.

Deletion of IκBα activates RelA to reduce acute pancreatitis in mice through up-regulation of Spi2A.

BACKGROUND & AIMS: The transcription factor nuclear factor-κB (NF-κB) (a heterodimer of NF-κB1p50 and RelA) is activated rapidly in acute pancreatitis (AP). However, it is not clear whether NF-κB promotes or protects against AP. We used the NF-κB inhibitor protein, inhibitor of κB (IκB)α, to study the roles of NF-κB in the development of AP in mice. METHODS: IκBα or the combination of IκBα and RelA selectively were deleted from pancreas of mice using the Cre/locus of cross-over P strategy; cerulein or L-arginine were used to induce AP. We performed microarray analyses of the IκBα- and RelA-deficient pancreata. DNA from healthy individuals and patients with acute or chronic pancreatitis were analyzed for variants in coding regions of alpha-1-antichymotrypsin. RESULTS: Mice with pancreas-specific deletion of IκBα had constitutive activation of RelA and a gene expression profile consistent with NF-κB activation; development of AP in these mice was attenuated and trypsin activation was impaired. However, AP was fully induced in mice with pancreas-specific deletion of IκBα and RelA. By using genome-wide expression analysis, we identified a cluster of NF-κB-regulated genes that might protect against the development of AP. The serine protease inhibitor 2A (Spi2a) was highly up-regulated in IκBα-deficient mice. Lentiviral-mediated expression of Spi2A reduced the development of AP in C57BL/6 and RelA-deficient mice. However, we did not correlate any variants of alpha-1-antichymotrypsin, the human homologue of Spi2a, with acute or chronic pancreatitis. CONCLUSIONS: Pancreas-specific deletion of IκBα results in nuclear translocation of RelA and reduces AP induction and trypsin activation in mice after administration of cerulein or L-arginine. Constitutive activation of RelA up-regulates Spi2A, which protects mice against the development of AP.

Assessing the pathological relevance of SPINK1 promoter variants.

The SPINK1 gene, encoding the human pancreatic secretory trypsin inhibitor, is one of the major genes involved in predisposition to chronic pancreatitis (CP). In this study we have assessed the potential functional impact of 11 SPINK1 promoter variants by means of both luciferase reporter gene assay and electrophoretic mobility shift assay (EMSA), using human pancreatic COLO-357 cells as an expression system. The 11 promoter variants were found to be separable into three distinct categories on the basis of the reporter gene assay results viz loss-of-function, gain-of-function and functionally neutral. These findings, which were validated by EMSA, concurred with data from previous deletion studies and DNase I footprinting assays. Further, binding sites for two transcription factors, HNF1 and PTF1, were newly identified within the SPINK1 promoter by virtue of their being affected by specific variants. Combining the functional data with epidemiological data (derived by resequencing the SPINK1 promoter region in French, German and Indian CP patients and controls), then allowed us to make meaningful inferences as to each variant's likely contribution to CP. We conclude that only the three promoter variants associated with a loss-of-function (ie, -53C>T, -142T>C and -147A>G) are likely to be disease-predisposing alterations.

Common CFTR haplotypes and susceptibility to chronic pancreatitis and congenital bilateral absence of the vas deferens.

CFTR mutations enhance susceptibility for idiopathic chronic pancreatitis (ICP) and congenital bilateral absence of the vas deferens (CBAVD); however, it is unknown why CFTR heterozygotes are at increased disease risk. We recently showed that common CFTR variants are associated with aberrantly spliced transcripts. Here, we genotyped for common CFTR variants and tested for associations in two ICP (ICP-A: 126 patients, 319 controls; ICP-B: 666 patients, 1,181 controls) and a CBAVD population (305 patients, 319 controls). Haplotype H10 (TG11-T7-470V) conferred protection (ICP-A: OR 0.19, P<0.0001; ICP-B: OR 0.78, P = 0.06; CBAVD OR 0.08, P<0.001), whereas haplotype H3 (TG10-T7-470M) increased disease risk (ICP-A: OR 8.34, P = 0.003; ICP-B: OR 1.88, P = 0.007; CBAVD: OR 5.67, P = 0.01). The risk of heterozygous CFTR mutations carriers for ICP (OR 2.44, P<0.001) and CBAVD (OR 14.73, P<0.001) was fully abrogated by the H10/H10 genotype. Similarly, ICP risk of heterozygous p.Asn34Ser SPINK1 mutation carriers (OR 10.34, P<0.001) was compensated by H10/H10. Thus, common CFTR haplotypes modulate ICP and CBAVD susceptibility alone and in heterozygous CFTR and p.Asn34Ser mutation carriers. Determination of these haplotypes helps to stratify carriers into high- and low-risk subjects, providing helpful information for genetic counseling.