Chronic pancreatitis: challenges and advances in pathogenesis, genetics, diagnosis, and therapy

Association of novel chymotrypsin C gene variations and haplotypes in patients with chronic pancreatitis in Chinese in Taiwan

BACKGROUND/AIMS

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.

METHODS

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.

RESULTS

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).

CONCLUSION

Novel CTRC gene variations and haplotypes are associated with CP in a Chinese population.

Genetic testing in other GI diseases

Gastrointestinal development is a complex process comprising folding of the endodermal layer to form the primitive gut tube, cell differentiation along its anteroposterior axis, the budding of the various organ primordia and development of derivative organs like the liver and pancreas and the colonisation of the gut with neuronal precursors. Genetic factors are increasingly recognised as playing a significant role in the disturbance of this developmental process which underlies congenital malformations and gastrointestinal disorders. Furthermore, genetic variation and its interaction with environmental influences play an important role in the pathogenesis of functional gastrointestinal disorders. In this review, we discuss the contribution of genetic variants, ranging from highly penetrant mutations and chromosomal abnormalities to genetic polymorphisms, to the pathogenesis of a number of structural and functional gastrointestinal disorders.

Endoscopic therapy for chronic pancreatitis: technical success, clinical outcomes, and complications

Chronic pancreatitis (CP) can cause failure of both the exocrine and endocrine portions of the gland. Pain is the most recalcitrant clinical complaint in CP. Generally, conservative measures are first attempted to manage pain. These include cessation of alcohol use and smoking, enzyme replacement therapy, and finally, opioid analgesia. Endoscopy can be employed to treat the pain and complications due to CP. The results of the only two prospective randomized controlled trials suggest that surgery has a more durable effect than endoscopic therapy in controlling pain. Both trials suffer from severe limitations, however, and endoscopy remains the preferred approach for many patients because of its minimally invasive nature. Endoscopic ultrasound celiac plexus block has limited value in helping to control pain. More randomized trials are needed, along with further technologic innovation to improve the current treatment modalities. When considering interventional therapy for a patient with CP, a tailored and multidisciplinary therapeutic approach should be taken.

Hereditary pancreatitis caused by mutation-induced misfolding of human cationic trypsinogen: a novel disease mechanism

We investigated the biochemical properties and cellular expression of the c.346C>T (p.R116C) human cationic trypsinogen (PRSS1) mutant, which we identified in a German family with autosomal dominant hereditary pancreatitis. This mutation leads to an unpaired Cys residue with the potential to interfere with protein folding via incorrect disulfide bond formation. Recombinantly expressed p.R116C trypsinogen exhibited a tendency for misfolding in vitro. Biochemical analysis of the correctly folded, purified p.R116C mutant revealed unchanged activation and degradation characteristics compared to wild type trypsinogen. Secretion of mutant p.R116C from transfected 293T cells was reduced to approximately 20% of wild type. A similar secretion defect was observed with another rare PRSS1 variant, p.C139S, whereas mutants p.A16V, p.N29I, p.N29T, p.E79K, p.R122C, and p.R122H were secreted normally. All mutants were detected in cell extracts at comparable levels but a large portion of mutant p.R116C was present in an insoluble, protease-sensitive form. Consistent with intracellular retention of misfolded trypsinogen, the endoplasmic reticulum (ER) stress markers immunoglobulin-binding protein (BiP) and the spliced form of the X-box binding protein-1 (XBP1s) were elevated in cells expressing mutant p.R116C. The results indicate that mutation-induced misfolding and intracellular retention of human cationic trypsinogen causes hereditary pancreatitis in carriers of the p.R116C mutation. ER stress triggered by trypsinogen misfolding represents a new potential disease mechanism for chronic pancreatitis.

Expression pattern, ethanol-metabolizing activities, and cellular localization of alcohol and aldehyde dehydrogenases in human pancreas: implications for pathogenesis of alcohol-induced pancreatic injury

BACKGROUND

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are major enzymes responsible for metabolism of ethanol. Genetic polymorphisms of ADH1B, ADH1C, and ALDH2 occur among racial populations. The metabolic effect and metabolites contribute to pathogenesis of pancreatic injury. The goal of this study was to determine the functional expressions and cellular localization of ADH and ALDH families in human pancreas.

METHODS

Fifty five surgical specimens of normal pancreas as well as 15 samples each for chronic pancreatitis and pancreatic cancer from archival formalin-fixed paraffin-embedded tissue specimens were investigated. Class-specific antibodies were prepared by affinity chromatographies from rabbit antisera raised against recombinant human ADH1C1, ADH4, ADH5, ADH7, ALDH1A1, ALDH2, and ALDH3A1. The isozyme expression patterns of ADH/ALDH were identified by isoelectric focusing, and the activities were assayed spectrophotometrically. The protein contents of ADH/ALDH isozymes were determined by immunoblotting, and the cellular localizations were detected by immunohistochemistry and histochemistry.

RESULTS

At 33 mM ethanol, pH 7.5, the activities were significantly different between allelic phenotypes of ADH1B. The activity of ALDH2-inactive phenotypes was slightly lower than ALDH2-active phenotypes at 200 microM acetaldehyde. The protein contents were in the following decreasing order: ALDH1A1, ALDH2, ADH1, and ADH5. ADH1B was detected in the acinar cells and ADH1C in the ductular, islet, and stellate cells. The expression of ADH1C appeared to be increased in the activated pancreatic stellate cells in chronic pancreatitis and pancreatic cancer.

CONCLUSIONS

Alcohol dehydrogenase and ALDH family members are differentially expressed in the various cell types of pancreas. ADH1C may play an important role in modulation of activation of pancreatic stellate cells.

Nonneoplastic mimickers of pancreatic neoplasms

CONTEXT

A variety of nonneoplastic conditions may form pancreatic masses that mimic carcinoma. Approximately 5% to 10% of pancreatectomies performed with the clinical diagnosis of pancreatic cancer prove on microscopic evaluation to be pseudotumors.

OBJECTIVES

To illustrate the clinical and pathologic characteristics of the 2 most frequent pseudotumoral inflammatory conditions, autoimmune pancreatitis and paraduodenal pancreatitis, and describe the criteria that may be useful in the differential diagnosis versus pancreatic carcinoma.

DATA SOURCES

Recent literature and the authors' experience with the clinical and pathologic characteristics of autoimmune pancreatitis and paraduodenal pancreatitis.

CONCLUSIONS

The knowledge of the clinical, radiologic, and pathologic findings in both autoimmune pancreatitis and paraduodenal pancreatitis is crucial in making the correct preoperative diagnosis. Autoimmune pancreatitis, which occurs in isolated or syndromic forms, is characterized by a distinctive fibroinflammatory process that can either be limited to the pancreas or extend to the biliary tree. Its correct preoperative identification on biopsy material with ancillary immunohistochemical detection of dense immunoglobulin G4-positive plasma cell infiltration is possible and crucial to prevent major surgery and to treat these patients with steroid therapy. Paraduodenal pancreatitis is a special form of chronic pancreatitis that affects young males with a history of alcohol abuse and predominantly involves the duodenal wall in the region of the minor papilla. Pathogenetically, the anatomical and/or functional obstruction of the papilla minor, resulting from an incomplete involution of the intraduodenal dorsal pancreas, associated with alcohol abuse represents the key factor. Endoscopic drainage of the papilla minor, with decompression of the intraduodenal and dorsal pancreas, might be considered in these patients.

Alcohol use and cigarette smoking as risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis

BACKGROUND & AIMS

Alcohol use and cigarette smoking are associated with various pancreatic diseases, but it is not known whether they associate with post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). We performed a retrospective case-control study to determine if these activities increase the risk of PEP.

METHODS

We identified 7638 patients who had undergone ERCP in the University of Michigan Health System and applied exclusion criteria to identify 123 with PEP. We randomly selected 308 age- and sex-stratified controls (2.5-fold case sample); after applying exclusion criteria 248 remained. In a masked fashion, we collected data for alcohol use, cigarette smoking, and 5 internal control variables: suspected sphincter of Oddi dysfunction (SOD), pancreatic sphincterotomy, moderate/difficult cannulation, 2 or more pancreatic injections, and pancreatic stent placement.

RESULTS

The univariate model showed an increased frequency of PEP in current drinkers (P < .001), former drinkers (P < .001), and former smokers (P < .001), as well as patients who were suspected of having SOD (P < .001), had undergone pancreatic sphincterotomy (P < .001), had a moderate/difficult cannulation (P = .001), and/or had 2 or more pancreatic injections (P = .007). The frequency of PEP was reduced in current smokers (P < .001). The multivariate model showed that the only independent significant predictors of PEP were current drinking (odds ratio [OR], 4.70; 95% confidence interval [CI], 2.60-8.50; P < .0001), former cigarette smoking (OR, 3.29; 95% CI, 1.28-8.44; P < .013), suspected SOD (OR, 3.69; 95% CI, 1.94-7.02; P < .001), and pancreatic sphincterotomy (OR, 5.91; 95% CI, 2.04-17.14; P = .001).

CONCLUSIONS

Current alcohol use and potentially former cigarette smoking are new risk factors for PEP. It is important to consider these variables in designing PEP prevention trials.

[Autoimmune pancreatitis]

Autoimmune pancreatitis has been established as a special entity of pancreatitis. It is an enigmatic disease since it is adding an autoimmune etiology to the existing causes of pancreatitis. Morphological hallmarks of the disease are narrowing of the pancreatic duct system and the bile duct by periductal lymphoplasmocytic inflammation. This results in many cases in obstructive jaundice due to a mass-forming lesion in the pancreatic head mimicking pancreatic ductal adenocarcinoma. Therefore, patients will frequently undergo surgery. Histopathologically, the disease can be diagnosed by IgG4-positive plasma cells. Serologically, patients may present with elevated serum IgG and IgG4 levels. Other autoantibodies are also described. Association with other autoimmune manifestations in a wide range of organs is frequent. Autoimmune pancreatitis will respond to steroid treatment, which is of specific importance because pancreatic cancer is one of its clinical differential diagnoses. It is important to positively diagnose autoimmune pancreatitis, especially if the bile ducts are affected, since cholangitis may be or become a prominent problem before or after surgery.

Protective role of angiotensin II type 2 receptor signaling in a mouse model of pancreatic fibrosis

The renin-angiotensin system contributes to pathological processes in a variety of organs. In the pancreas, blocking the angiotensin II (AII) type 1 receptor (AT1) attenuates pancreatic fibrogenesis in animal models of pancreatitis. Because the role of the AII type 2 receptor (AT2) in modulating pancreatic injury is unknown we investigated the role of AT2 in pancreatic injury and fibrosis. Pancreatic fibrosis was induced by repetitive cerulein administration in C57BL/6 wild-type (WT) or AT2-deficient (AT2-/-) mice and assessed by morphology and gene expression at 10 days. There was no difference between WT and AT2-/- mice in the degree of acute pancreatic injury as assessed by amylase release at 9 and 12 h and by histological examination of the pancreas at 12 h. In contrast, parenchymal atrophy and fibrosis were more pronounced in AT2-/- mice compared with WT mice at 10 days. Fibrosis was accompanied by activation of pancreatic stellate cells (PSC) evaluated by Western blot analysis for alpha-smooth muscle actin and by immunocytochemistry; PSC activation was further increased in AT2-/- mice compared with WT mice. The level of pancreatic transforming growth factor-beta1 mRNA and protein after repetitive cerulein treatment was higher in AT2-/- mice than in WT mice. Our results demonstrate that, in contrast to AT1 receptor signaling, AT2 receptor signaling modulates protective antifibrogenic effects in a mouse model of cerulein-induced pancreatic fibrogenesis. We propose that the effects of AII on injury-induced pancreatic fibrosis may be determined by the balance between AT1 and AT2 receptor signaling.

Synergistic growth inhibitory effects of the dual endothelin-1 receptor antagonist bosentan on pancreatic stellate and cancer cells

Pancreatic stellate cells (PSC) play a key role in pancreatic fibrosis. Activation of PSC occurs in response to pro-fibrogenic stimuli and is maintained by autocrine loops of mediators, such as endothelin (ET)-1. Here, we have evaluated effects of the dual ET receptor antagonist bosentan in models of pancreatic fibrogenesis and cancer. Cell culture studies revealed that PSC and DSL6A pancreatic cancer cells expressed both ET-1 and ET receptors. Bosentan efficiently inhibited proliferation of both cell types and collagen synthesis in PSC. Expression of the myofibroblastic marker alpha-smooth muscle actin, connective tissue growth factor, and ET-1 itself in PSC was reduced, while expression of matrix metalloproteinase-9 was enhanced. Like PSC, DSL6A cells secrete less ET-1 when cultured with bosentan. In a rat model of pancreatic fibrosis, chronic pancreatitis induced by dibutyltin dichloride, a tendency towards a diminished disease progression was observed in a subgroup of rats with less severe disease. Together, our results indicate that bosentan exerts antifibrotic and antitumor effects in vitro. Its efficiency in vivo warrants further investigation.

Protective effect of salvianolic acid B on chronic pancreatitis induced by trinitrobenzene sulfonic acid solution in rats

OBJECTIVES

To investigate the effects of salvianolic acid B (Sal-B) on pancreatic damage in experimental chronic pancreatitis.

METHODS

Chronic pancreatitis was induced by infusion of trinitrobenzene sulfonic acid into the pancreatic duct in male Sprague-Dawley rats. From the beginning of 5 weeks, the rats in group 2 were treated with Sal-B by gavage for 8 weeks. Salvianolic acid B was given at a daily dose of 10 mg/kg body weight. At the end of 12 weeks, the levels of serum biochemical indexes were measured on an automatic biochemical analyzer; serum hyaluronic acid and laminin levels were determined by radioimmunoassay; pancreatic tissue malondialdehyde (MDA) was analyzed, and the degree of pancreatic damage was determined.

RESULTS

The level of serum biochemical indexes were similar in all groups (P > 0.05 for all). Salvianolic acid B treatment did not obviously reduce hyaluronic acid and laminin concentration in blood (P > 0.05). Salvianolic acid B treatment decreased MDA concentration in pancreatic tissue (P < 0.01). Salvianolic acid B clearly improved pancreatic histological findings and prevented the activation of pancreatic stellate cells.

CONCLUSIONS

Sal-B treatment decreased MDA concentration in pancreatic tissue, attenuated morphological pancreatic damage, and prevented the activation of pancreatic stellate cells in experimental chronic pancreatitis.

Chronic pancreatitis: genetics and pathogenesis

Chronic pancreatitis (CP) is a persistent inflammation of the pancreas. Over the past 12 years, genetic studies of hereditary, familial, and idiopathic forms of CP have made great progress in defining the disease pathogenesis. Identification of gain-of-function missense and copy number mutations in the cationic trypsinogen gene (PRSS1) and loss-of-function variants in both the pancreatic secretory trypsin inhibitor (SPINK1) and chymotrypsinogen C (CTRC) genes has firmly established the pivotal role of prematurely activated trypsin within the pancreas in the etiology of CP. Loss-of-function variants in the cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-sensing receptor (CASR) genes also increase the risk of CP. Here, we review recent developments in this rapidly evolving field, highlight the importance of gene-gene and gene-environment interactions in causing the disease, and discuss the opportunities and challenges in identifying novel genetic factors that affect susceptibility/resistance to CP.

Pathogenesis of chronic pancreatitis: a comprehensive update and a look into the future

Chronic pancreatitis is a relatively frequent condition usually caused by alcoholic abuse but also due to recurrent gallstone disease, metabolic endocrine disorders and haemochromatosis, among others. Specific types such as hereditary and autoimmune pancreatitis should be particularly kept in mind and emphasized, as they require specific treatment and attention. The possibility to identify gene mutations has also increased and this is likely to decrease the overall total number of "idiopathic" chronic pancreatitis cases. Pancreatic stellate cells have been identified as potential key players in the progression of chronic pancreatitis and the development of fibrogenesis, which are activated either during repeated attacks of necro-inflammation or directly by toxic factors. The inhibition or modulation of pancreatic stellate cells could represent a way of potential intervention in patients with chronic pancreatitis in the future.

A randomized controlled trial of antioxidant supplementation for pain relief in patients with chronic pancreatitis

BACKGROUND & AIMS

Oxidative stress has been implicated in the pathophysiology of chronic pancreatitis (CP). We evaluated the effects of antioxidant supplementation on pain relief, oxidative stress, and antioxidant status in patients with CP.

METHODS

In a placebo-controlled double blind trial, consecutive patients with CP were randomized to groups that were given placebo or antioxidants for 6 months. The primary outcome measure was pain relief, and secondary outcome measures were analgesic requirements, hospitalization, and markers of oxidative stress (thiobarbituric acid-reactive substances [TBARS]) and antioxidant status (ferric-reducing ability of plasma [FRAP]).

RESULTS

Patients (age 30.5+/-10.5 years, 86 male, 35 alcoholic, and 92 with idiopathic CP) were assigned to the placebo (n=56) or antioxidant groups (n=71). After 6 months, the reduction in the number of painful days per month was significantly higher in the antioxidant group compared with the placebo group (7.4+/-6.8 vs 3.2+/-4, respectively; P< .001; 95% CI, 2.07, 6.23). The reduction in the number of analgesic tablets per month was also higher in the antioxidant group (10.5+/-11.8 vs 4.4+/-5.8 respectively; P= .001; 95% CI, 2.65, 9.65). Furthermore, 32% and 13% of patients became pain free in the antioxidant and placebo groups, respectively (P= .009). The reduction in the level of TBARS and increase in FRAP were significantly higher in the antioxidant group compared with the placebo group (TBARS: placebo 1.2+/-2.7 vs antioxidant 3.5+/-3.4 nmol/mL; P= .001; 95% CI 0.96, 3.55; FRAP: placebo -5.6+/-154.9 vs antioxidant 97.8+/-134.9 microMFe(+2) liberated, P= .001, 95% CI 44.98, 161.7).

CONCLUSIONS

Antioxidant supplementation was effective in relieving pain and reducing levels of oxidative stress in patients with CP.

Usefulness of serum IgG4 in the diagnosis and follow up of autoimmune pancreatitis: A systematic literature review and meta-analysis

High circulating serum immunoglobulin G4 (IgG4) levels have been proposed as a marker of autoimmune pancreatitis (AIP). The aim of the present study was to review the data existing in the English literature on the usefulness of the IgG4 serum levels in the diagnosis and follow up of patients with AIP. A total of 159 patients with AIP and 1099 controls were described in seven selected papers reporting the usefulness of serum IgG4 in diagnosing AIP. In total, 304 controls had pancreatic cancer, 96 had autoimmune diseases, and the remaining 699 had other conditions. The summary receiver-operating characteristic curve analysis was carried out by means of Meta-DiSc open-access software. Serum IgG4 showed good accuracy in distinguishing between AIP and the overall controls, pancreatic cancer and other autoimmune diseases (area under the curve [+/- SE]: 0.920 +/- 0.073, 0.914 +/- 0.191, and 0.949 +/- 0.024, respectively). The studies analyzed showed significantly heterogeneous specificity values in each of the three analyses performed. The analysis of the four studies comparing AIP and pancreatic cancers also showed significantly heterogeneous values of sensitivities and odds ratios. Regarding the usefulness of IgG4 as a marker of efficacy of steroid treatment, a decrease in the serum concentrations of IgG4 was found in the four available studies. The serum IgG4 subclass is a good marker of AIP, and its determination should be included in the diagnostic workup of this disease. However, the heterogeneity of the studies published until now means that more studies are necessary in order to better evaluate the true accuracy of IgG4 in discriminating AIP versus other autoimmune diseases.

Does the pain-protective GTP cyclohydrolase haplotype significantly alter the pattern or severity of pain in humans with chronic pancreatitis?

Background

Pain is often a dominant clinical feature of chronic pancreatitis but the frequency and severity is highly variable between subjects. We hypothesized that genetic polymorphisms contribute to variations in clinical pain patterns. Since genetic variations in the GTP cyclohydrolase (GCH1) gene have been reported to protect some patients from pain, we investigated the effect of the "pain protective haplotype" in well characterized patients with chronic pancreatitis (CP) or recurrent acute pancreatitis (RAP) from the North American Pancreatitis Study 2 (NAPS2).

Results

Subjects in the NAPS2 study were asked to rank their pain in one of 5 categories reflecting different levels of pain frequency and severity. All subjects were genotyped at rs8007267 and rs3783641 to determine the frequency of the GCH1 pain-protective haplotype. In Caucasian subjects the frequency of the pain-protective GCH1 haplotype was no different in the control group (n = 236), CP patients (n = 265), RAP patients (N = 131), or in CP patients subclassified by pain category compared to previously reported haplotype frequencies in the general Caucasian population.

Conclusion

The GCH1 pain-protective haplotype does not have a significant effect on pain patterns or severity in RAP or CP. These results are important for helping to define the regulators of visceral pain, and to distinguish different mechanisms of pain.

[Diagnostics and therapy of chronic pancreatitis]

Chronic pancreatitis (CP) is characterized by progressive, chronic inflammation of the pancreas, resulting in loss of exocrine and endocrine function and chronic abdominal pain. In most cases, CP is induced by long-term alcoholism. The second most frequent diagnosis is idiopathic CP, in the absence of known causes of CP. However, the identification of genetic and immunological causes continuously reduces the number of cases classified as idiopathic pancreatitis. Common symptoms of CP comprise abdominal pain radiating to the back, diarrhea, steatorrhea and the development of diabetes. The diagnosis is mainly based on clinical features, typical morphological findings such as pancreatic calcifications, duct stenoses and dilatations, as well as pathologic pancreatic function tests. Treatment of CP includes watch and wait strategies in asymptomatic patients, symptomatic treatment of the clinical features such as pain, exocrine and endocrine insufficiency, as well as interventional or surgical therapy of complications such as pseudocysts, pancreatic duct stenosis, stones or biliary obstruction.

Reduction of inflammation and chronic tissue damage by omega-3 fatty acids in fat-1 transgenic mice with pancreatitis

Pancreatitis is a severe debilitating disease with high morbidity and mortality. Treatment is mostly supportive, and until now there are no clinically useful strategies for anti-inflammatory therapy. Although omega-3 polyunsaturated fatty acids (n-3 PUFA) are known to have anti-inflammatory effects, the utility of these fatty acids in the alleviation of pancreatitis remained to be investigated. The aim of this study was to examine the effect of n-3 PUFA on both acute and chronic pancreatitis in a well-controlled experimental system. We used the fat-1 transgenic mouse model, characterized by endogenously increased tissue levels of n-3 PUFA, and their wild-type littermates to examine the effect of n-3 PUFA on both acute and chronic cerulein-induced pancreatitis. Disease activity and inflammatory status were assessed by both histology and molecular methods. In acute pancreatitis, fat-1 mice showed a trend towards decreased necrosis and significantly reduced levels of plasma IL-6 levels as well as reduced neutrophil infiltration in the lung. In chronic pancreatitis there was less pancreatic fibrosis and collagen content accompanied by decreased pancreatic stellate cell activation in the fat-1 animals with increased n-3 PUFA tissue levels as compared to wild-type littermates with high levels of omega-6 (n-6) PUFA in their tissues. Our data provide evidence for a reduction of systemic inflammation in acute pancreatitis and of tissue fibrosis in chronic pancreatitis by increasing the tissue content of omega-3 polyunsaturated fatty acids. These results suggest a beneficial potential for n-3 PUFA supplementation in acute and particularly chronic pancreatitis.

Overexpression of interleukin-1beta in the murine pancreas results in chronic pancreatitis

BACKGROUND & AIMS

Chronic pancreatitis is a significant cause of morbidity and a known risk factor for pancreatic adenocarcinoma. Interleukin-1beta is a proinflammatory cytokine involved in pancreatic inflammation. We sought to determine whether targeted overexpression of interleukin-1beta in the pancreas could elicit localized inflammatory responses and chronic pancreatitis.

METHODS

We created a transgenic mouse model (elastase sshIL-1beta) in which the rat elastase promoter drives the expression of human interleukin-1beta. Mice were followed up for up to 2 years. Pancreata of elastase sshIL-1beta mice were analyzed for chronic pancreatitis-associated histologic and molecular changes. To study the potential effect of p53 mutation in chronic pancreatitis, elastase sshIL-1beta mice were crossed with p53(R172H) mice.

RESULTS

Three transgenic lines were generated, and in each line the pancreas was atrophic and occasionally showed dilation of pancreatic and biliary ducts secondary to proximal fibrotic stenosis. Pancreatic histology showed typical features of chronic pancreatitis. There was evidence for increased acinar proliferation and apoptosis, along with prominent expression of tumor necrosis factor-alpha; chemokine (C-X-C motif) ligand 1; stromal cell-derived factor 1; transforming growth factor-beta1; matrix metallopeptidase 2, 7, and 9; inhibitor of metalloproteinase 1; and cyclooxygenase 2. The severity of the lesions correlated well with the level of human interleukin-1beta expression. Older mice displayed acinar-ductal metaplasia but did not develop mouse pancreatic intraepithelial neoplasia or tumors. Elastase sshIL-1beta*p53(R172H/+) mice had increased frequency of tubular complexes, some of which were acinar-ductal metaplasia.

CONCLUSIONS

Overexpression of interleukin-1beta in the murine pancreas induces chronic pancreatitis. Elastase sshIL-1beta mice consistently develop severe chronic pancreatitis and constitute a promising model for studying chronic pancreatitis and its relationship with pancreatic adenocarcinoma.

Pancreatic exocrine insufficiency in LXRbeta-/- mice is associated with a reduction in aquaporin-1 expression

Liver X receptors (LXRs) alpha and beta are nuclear oxysterol receptors with a key role in cholesterol, triglyceride, and glucose metabolism. In LXRbeta(-/-) mice on a normal diet, there is a reduction in size of perigonadal fat pad and, on high-fat diet there is resistance to obesity. In the present study, we investigated the reason for the resistance of LXRbeta(-/-) mice to weight gain. In LXRbeta(-/-) mice we found pancreatic exocrine insufficiency with reduced serum levels of amylase and lipase, reduced proteolytic activity in feces, chronic inflammatory infiltration, and, in the ductal epithelium, an increased apoptosis without compensatory proliferation. Electron microscopy revealed ductal dilatation with intraductal laminar structures characteristic of cystic fibrosis. To investigate the relationship between LXRbeta and pancreatic secretion, we studied the expression of LXRbeta and the water channel, aquaporin-1 (AQP1), in the ductal epithelium of the pancreas. In WT mice, ductal epithelial cells expressed LXRbeta in the nuclei and AQP1 on the plasma membrane. In LXRbeta(-/-) mice neither LXRbeta nor AQP1 was detectable. Moreover, in WT mice the LXR agonist (T2320) increased AQP1 gene expression. These data demonstrate that in LXRbeta(-/-) mice dietary resistance to weight gain is caused by pancreatic insufficiency and that LXRbeta regulates pancreatic exocrine secretion through the control of AQP1 expression. Pancreatic exocrine insufficiency is the main cause of malabsorption syndrome responsible for weight loss in adults and growth failure in children. Several genes are known to be involved in the pathogenesis and susceptibility to pancreatic insufficiency. LXRbeta should be included in that list.

[Genetic risk factors in chronic pancreatitis]

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.

Source validation of pancreatitis-related hospital discharge diagnoses notified to a national registry in the Netherlands

BACKGROUND

National and regional disease registries are often used for epidemiological studies and validation analyses are scarce. We analyzed the reliability of the National Information System on Hospital Care (NISHC) registry used to classify admissions for acute and chronic pancreatitis in the Netherlands.

METHODS

All pancreas-related discharge diagnoses notified by the Academic Medical Center to the NISHC were retrieved for a 2-year time period. A review of multidisciplinary patient reports was conducted to verify these diagnoses.

RESULTS

284 patients were notified to the NISHC, relating to 483 admissions with 523 pancreas-related discharge diagnoses. Of these diagnoses, 112 were coded as acute pancreatitis, 250 as chronic pancreatitis and 161 were classified as pseudocysts and other pancreatic diseases. The positive predictive value for acute pancreatitis diagnosis codes was 77.7% and 46 additional acute pancreatitis diagnoses were identified, ultimately leading to an underestimation of the total number of acute pancreatitis diagnoses of 15.8%. The positive predictive value for discharge diagnoses regarding chronic pancreatitis was 83.6% and 57 additional chronic pancreatitis diagnoses were identified, finally resulting in an underestimation of the total number of chronic pancreatitis diagnoses of 6%.

CONCLUSION

There is a substantial miscoding on a person level of discharge diagnoses of acute and chronic pancreatitis. On a group level, when miscoding between categories is leveled out, actual numbers of admission are only slightly underestimated.

Genetic aspects of tropical calcific pancreatitis

Tropical calcific pancreatitis (TCP) is a subtype of chronic pancreatitis which is unique to tropical regions. Patients present at young age with recurrent abdominal pain, nutritional deficiencies, and insulin-requiring diabetes. For a long time, the aetiology of this disorder was poorly understood. Several environmental factors, such as malnutrition or the consumption of toxic food components such as cyanogenic glycosides, were proposed as pathogenic factors. In the last decade, a major impact on the understanding of the aetiology of TCP has come from genetic studies on hereditary and idiopathic chronic pancreatitis. Genetic alterations in at least five genetic loci are clearly associated with chronic pancreatitis in the Western world. These include alterations in genes coding for trypsinogens, the most abundant digestive enzymes (PRSS1 and PRSS2), the trypsin inhibitor (SPINK1) and the trypsin-degrading enzyme, chymotrypsinogen C (CTRC). In addition, alterations in the cystic fibrosis (CFTR) gene are associated with idiopathic pancreatitis. TCP clinically resembles non-alcoholic chronic pancreatitis of Western countries, suggesting that similar genetic defects might also be of importance in this disease entity. Indeed, alterations in at least two genes, SPINK1 and CTRC, are strongly associated with TCP. The current review focuses on the recent developments in the understanding of the genetic basis of inherited pancreatitis, with special emphasis on TCP.

Cause and effect relationship of malnutrition with idiopathic chronic pancreatitis: prospective case-control study

BACKGROUND AND AIM

Patients with chronic pancreatitis are often malnourished. The role of malnutrition in the pathogenesis of chronic pancreatitis is unclear. The aim of the present article was to study prospectively the cause and effect relationship of malnutrition with idiopathic chronic pancreatitis in a case-control study.

METHODS

Consecutive patients with chronic pancreatitis underwent anthropometry, nutritional and dietary assessments. For dietary assessment, food frequency questionnaire and 24-hour dietary recall methods were used. Primary outcome measure was cause and effect relationship of malnutrition with idiopathic chronic pancreatitis.

RESULTS

Of 201 patients with chronic pancreatitis, 120 had idiopathic chronic pancreatitis (mean age 29.60 years, 74 males) who formed the study group. None of the patients consumed cassava. The nutritional status and dietary intake of the patients before the onset of chronic pancreatitis were comparable with those of controls with 20.6% of patients and 22.5% of controls being malnourished (body mass index [BMI] < 18.5). After the onset of chronic pancreatitis, 56.5% of patients lost weight and significantly more patients became malnourished compared with controls (45.8% vs 22.5%; P < 0.001). The causes of weight loss were diabetes, higher calories from proteins, and pseudocyst.

CONCLUSION

Malnutrition was not a cause of idiopathic chronic pancreatitis and weight loss occurred as an effect of chronic pancreatitis. Cassava was not found to be a cause of idiopathic chronic pancreatitis.

Genetics of pancreatitis: a guide for clinicians

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.

Abnormal crosstalk between pancreatic acini and macrophages during the clearance of apoptotic cells in chronic pancreatitis

In chronic pancreatitis (CP), both the progressive loss of acinar parenchyma and aggressive fibro-inflammatory reactions ultimately lead to irreversible organ destruction. Dying cells are normally removed by macrophages and elimination is associated with anti-inflammatory cytokine switch. We investigated whether defective clearance of damaged acini by macrophages such as compromised phagocytosis or altered cytokine reaction occurs in CP and thus represents a causative link between acinar loss and fibro-inflammation. In a checkerboard-like co-culture system, we assessed normal and CP macrophages for their phagocytic and cytokine responses to dying pancreatic acinar cells of normal or CP origin by FACS, confocal microscopy, QRT-PCR, and ELISA. In CP, phagocytosis of apoptotic acini by macrophages was not impaired; however, the associated cytokine responses were gradually perturbed. Most interestingly, only normal acini suppressed TGFbeta1 expression and accumulation specifically in normal macrophage cultures, while CP acini lost this ability. Both types of apoptotic acini induced pro-inflammatory cytokine bursts of varying strength in both types of macrophages; however, the most significant difference (more than 50-fold higher expression of IL-1beta, IL-6, and IL-8) was evident between CP/CP and normal/normal combinations, indicating that acinar and macrophage alterations synergistically lead to the ultimate CP-specific bias. In combination with in situ data comparing circulating inflammatory cells to pancreatic resident ones, our results indicate that cytokine expression in inflammatory cells undergoes spatiotemporal modulation, most likely through a successive interplay of acinar, stromal, and circulating factors. Thus, clearance of injured pancreatic acini by macrophages is associated with a unique cytokine reaction which may constitute a basis for progression of SAPE (sentinel acute pancreatitis event) to the irreversible fibro-inflammation in CP.

Disconnected pancreatic duct syndrome in severe acute pancreatitis: clinical and imaging characteristics and outcomes in a cohort of 31 cases

BACKGROUND

Information regarding the natural history, clinical characteristics, and outcomes of disconnected pancreatic duct syndrome (DPDS) is limited.

OBJECTIVE

To describe clinical characteristics and outcomes of DPDS.

DESIGN

A retrospective review of the Mayo Clinic endoscopy and hospital service database.

SETTING

Tertiary-referral center.

PATIENTS

We identified 31 DPDS cases from 1999 to 2006.

INTERVENTIONS

Endoscopic drainage of pancreatic-fluid collections.

MAIN OUTCOME MEASUREMENTS

The relationship between demographic and clinical data with endoscopic treatment and clinical outcomes in DPDS cases.

RESULTS

The median patient age was 53 years (range 20-83 years); 48% were men. The most common etiology of acute pancreatitis (AP) was biliary (55%) followed by idiopathic (27%). The median interval between the diagnoses of AP and DPDS was 56 days (range 3-251 days); the median follow-up after the last ERCP or surgical procedure was 7 months (range 0-90 months). The DPDS location included the following: pancreas head 6%, neck 58%, body 26%, and tail 10%. Twenty-six patients had initial endoscopic treatment (19 had long-term improvement; 7 failed treatment and required surgery) and 5 underwent immediate surgery. Mortality was 0%; 26% developed chronic pancreatitis (CP) and 16% diabetes mellitus (DM); 10% resolved completely, 45% had smaller fluid collections, and 26% patients were lost to follow-up. No relationship between demographic and clinical data with endoscopic and clinical outcomes was found.

CONCLUSIONS

Endoscopic treatment temporarily improved DPDS, with a failure rate of 23%. Immediate surgery was not required in all cases. CP and/or pancreatic atrophy occurred relatively shortly after the DPDS diagnosis in 26% and DM in 16% of cases. DPDS did not lead to mortality. Early surgery may be considered after initially stabilizing the fluid collection with endoscopic therapy.

Surgical Treatment of Alcohol-Associated Chronic Pancreatitis: The Challenges and Pitfalls

Long-term excessive alcohol consumption is the most common risk factor for the development of chronic pancreatitis. Management of patients with alcohol-associated chronic pancreatitis can be complicated by problems associated with dependency, psychosocial burden, and physical changes like malnutrition and hepatic insufficiency. The records of 372 consecutive patients who underwent lateral pancreaticojejunostomy (LPJ, n = 184), pancreatoduodenectomy (PD, n = 97), or distal pancreatectomy (DP, n = 91) for chronic pancreatitis were retrospectively analyzed. Long-term outcome was assessed by patient survey with a median follow up of 5.5 ± 0.2 years. Of 372 patients, 171 underwent surgery for alcohol-associated chronic pancreatitis. According to patient questioning, the prevalence of alcohol cessation before surgery in the 171 patients was 81 per cent. Operative morbidity in the 171 patients was 20 per cent, 50 per cent, and 26 per cent after LPJ, PD, and DP, respectively, with an overall perioperative mortality rate of 2 per cent. None of the patients developed delirium tremens using an alcohol withdrawal protocol. Continued alcohol abuse before surgery did not affect perioperative morbidity ( P > 0.05). Follow up was available for a total of 229 patients, of which 39 per cent with alcohol-associated chronic pancreatitis had died compared with 16 per cent in the nonalcohol group ( P < 0.001). Of the remaining 171 patients, 45 per cent with alcohol-associated chronic pancreatitis had good pain control compared with 49 per cent of the remainder ( P > 0.05). Continuation of alcohol abuse after operation did not affect success for pain control at follow up ( P > 0.05). Surgical treatment of alcohol-associated chronic pancreatitis can be performed with similar morbidity and mortality compared with other forms of chronic pancreatitis. Alcohol cessation is preferred but not mandated to achieve good operative long-term outcome. Caution needs to be taken to prevent postoperative alcohol withdrawal. Long-term follow up with psychosocial support and management of co-existing addictions is important.

Diagnosis and treatment of chronic pancreatitis: an analysis of 303 cases

AIM: To investigate the diagnosis and treatment status of chronic pancreatitis (CP) and its etiology-related factors.

METHODS: The clinical data of 303 CP patients in West China Hospital of Sichuan University from 1996 to 2006 were retrospectively analyzed.

RESULTS: Etiologically, patients with biliary diseases or over 5-year alcohol-drinking history accounted for a percentage of 30.7% and 37.0%, respectively. Furthermore, among biliary CP patients, 31.2% were found with a long-term alcohol-drinking history. Abdominal pain was the most common symptom, which covered a percentage of 86.8%. Complications were found in 146 of 303 CP patients (48.2%). Imaging techniques confirmed 196 patients (64.7%), while 38.9%, 53.5% and 7.6% of all the patients received drug treatment, surgical treatment and endoscopic treatment, respectively.

CONCLUSION: CP occurrence usually results from multiple etiological factors with a higher complication rate. Imaging examinations play an important role in the diagnosis of this disease.

Keratin overexpression levels correlate with the extent of spontaneous pancreatic injury

Mutation of the adult hepatocyte keratins K8 and K18 predisposes to liver disease. In contrast, exocrine pancreas K8 and K18 are dispensable and are co-expressed with limited levels of membrane-proximal K19 and K20. Overexpression of mutant K18 or genetic ablation of K8 in mouse pancreas is well tolerated whereas overexpression of K8 causes spontaneous chronic pancreatitis. To better understand the effect of exocrine pancreatic keratin overexpression, we compared transgenic mice that overexpress K18, K8, or K8/K18, associated with minimal, modest, or large increases in keratin expression, respectively, with nontransgenic wild-type (WT) mice. Overexpression of the type-II keratin K8 up-regulated type-I keratins K18, K19, and K20 and generated K19/K20-containing neocytoplasmic typical or short filaments; however, overexpression of K18 had no effect on K8 levels. K8- and K18-overexpressing pancreata were histologically similar to WT, whereas K8/K18 pancreata displayed age-enhanced vacuolization and atrophy of the exocrine pancreas and exhibited keratin hyperphosphorylation. Zymogen granules in K8/K18 pancreata were 50% smaller and more dispersed than their normal apical concentration but were twice as numerous as in WT controls. Therefore, modest keratin overexpression has minor effects on the exocrine pancreas whereas significant keratin overexpression alters zymogen granule organization and causes aging-associated exocrine atrophy. Keratin absence or mutation is well tolerated after pancreatic but not liver injury, whereas excessive overexpression is toxic to the pancreas but not the liver when induced under basal conditions.

The role of total pancreatectomy and islet autotransplantation for chronic pancreatitis

Total pancreatectomy and islet autotransplantation are done for chronic pancreatitis with intractable pain when other treatment measures have failed, allowing insulin secretory capacity to be preserved, minimizing or preventing diabetes, while at the same time removing the root cause of the pain. Since the first case in 1977, several series have been published. Pain relief is obtained in most patients, and insulin independence preserved long term in about a third, with another third having sufficient beta cell function so that the surgical diabetes is mild. Islet autotransplantation has been done with partial or total pancreatectomy for benign and premalignant conditions. Islet autotransplantation should be used more widely to preserve beta cell mass in major pancreatic resections.

Nutrition support in pancreatitis

Nutrition support is especially important in patients who have pancreatitis, as these patients have high metabolic needs and are usually unable to ingest sufficient calories from an oral diet because of pain or intestinal dysfunction. Clinicians must assess severity of the disease carefully, as initiation and timing of nutrition support are crucial. Depending on the severity, early nutrition support may be unnecessary, while late support ultimately may lead to worse outcomes. Route of nutrition support also plays an important role in treatment. The clinician has many alternatives from which to choose, including enteral nutrition given nasogastrically or nasojejunally, or parenteral nutrition given through a central line. This article explores the role of nutrition support in the outcome of pancreatitis and provides guidelines to aid the clinician in caring for patients who have acute and chronic pancreatitis.

Radiologic assessment of acute and chronic pancreatitis

The capabilities of various imaging modalities, including CT, MRI, and ultrasound, have markedly increased over recent years. This has translated into improved detection and improved characterization of various pathologic processes. This article discusses the current role of imaging in the evaluation of acute and chronic pancreatitis. CT remains a major focal point in issues related to acute pancreatitis, whereas MRI (and magnetic resonance cholangiopancreatography) plays a larger role in chronic pancreatitis.

Epidemiology, aetiology and outcome of acute and chronic pancreatitis: An update

Over the past decades several epidemiological studies have been published reporting on incidence trends, hospital admissions, etiological factors and outcome of both acute and chronic pancreatitis. Over time, the incidence of acute pancreatitis has increased in the Western countries. Also, the number of hospital admissions for both acute and chronic pancreatitis have increased. These upward time trends possibly reflect a change in the prevalence of main etiological factors (e.g. gallstones and alcohol consumption) and cofactors such as obesity and genetic susceptibility. Acute and chronic pancreatitis are associated with significant morbidity and mortality and a substantial use of health care resources. Although the case-fatality rate of acute pancreatitis decreased over time, the overall population mortality did not change for both acute and chronic pancreatitis. This chapter will focus on recent developments in the epidemiology, aetiology, natural course and outcome of both acute and chronic pancreatitis.

Idiopathic chronic pancreatitis

Idiopathic pancreatitis is diagnosed in up to 25% of patients with chronic pancreatitis by exclusion of other potential causes including rare ones. It has been shown that idiopathic pancreatitis comprises two clinically distinct entities characterised as early-onset and late-onset disease and that the natural courses of both forms differ from that of alcoholic chronic pancreatitis. Due to considerable progress in our understanding of hereditary and autoimmune mechanisms for development of chronic pancreatitis, a specific aetiology of chronic pancreatitis can be determined in an increasing proportion of cases. Nevertheless, the aetiopathogenesis of idiopathic chronic pancreatitis frequently remains obscure. This review focuses on the pathogenetic relevance of various endogenous and exogenous (co-)factors for the manifestation and the natural course of the disease. Moreover, it presents a multifactorial model for understanding the development of idiopathic chronic pancreatitis.

Association of cystic fibrosis transmembrane conductance regulator (CFTR) mutation/variant/haplotype and tumor necrosis factor (TNF) promoter polymorphism in hyperlipidemic pancreatitis

BACKGROUND

The mechanism by which hypertriglyceridemia (HTG) leads to pancreatitis is not clear. We sought to determine whether the genes involved in pancreatic ductal or acinar cell injury, including the cationic trypsinogen gene [protease, serine, 1 (trypsin 1) (PRSS1)], the pancreatic secretory trypsin inhibitor gene [serine peptidase inhibitor, Kazal type 1 (SPINK1)], the cystic fibrosis transmembrane conductance regulator gene [cystic fibrosis transmembrane conductance regulator (ATP-binding cassette subfamily C, member 7) (CFTR)], and inflammation genes such as tumor necrosis factor [tumor necrosis factor, TNF superfamily, member 2 (TNF)] are associated with hyperlipidemic pancreatitis (HLP) in patients with HTG.

METHODS

We performed genetic analysis of 126 HTG patients in Taiwan (46 with HLP and 80 without HLP). The entire coding and intronic regions of the PRSS1, SPINK1, and CFTR genes were identified by heteroduplex analysis techniques and were confirmed by sequencing analysis. The presence of 125G/C, 1001 + 11C>T, 1540A>G (Met470Val), 2694T>G, and 4521G>A in CFTR, the presence of 272C>T in SPINK1, and TNF promoter polymorphisms (nucleotide positions 1031, 863, 857, 308, and 308) were measured by direct sequencing.

RESULTS

Of the 126 HTG patients, 13 (10.3%) carried a CFTR mutation. No PRSS1 or SPINK1 mutations were detected in our patients or in HTG controls. The CFTR gene mutation rates in HTG with and without HLP were 26.1% (12 of 46) and 1.3% (1 of 80), respectively (P <0.0001). The CFTR gene mutations were all Ile556Val. A multivariate analysis of HTG patients indicated that triglycerides, CFTR 470Val, and TNF promoter 863A were independent risk markers for HLP.

CONCLUSIONS

This genetic study is the first one to address the association of HLP with the CFTR mutation/variant/haplotype and TNF promoter polymorphism in a Chinese HTG population. The results suggest that the occurrence of HLP is multifactorial and polygenic.