Comparison of histological features and inflammatory cell reaction in alcoholic, idiopathic and tropical chronic pancreatitis

Genetics and Genomics of Chronic Pancreatitis with a Focus on Disease Biology and Molecular Pathogenesis

Chronic pancreatitis is a long-term fibroinflammatory condition of the pancreas with varying incidences across countries. The recent increase in its occurrence implies the involvement of genetic, hereditary, and unconventional risk factors. However, there is a lack of updated literature on recent advances in genetic polymorphisms of chronic pancreatitis. Therefore, this review aims to present recent findings on the genetic implications of chronic pancreatitis based on individual gene mechanisms and to discuss epigenetics and epistasis involved in the disease. Four mechanisms have been implicated in the pathogenesis of chronic pancreatitis, including premature activation of proteases, endoplasmic reticulum stress, ductal pathway dysfunction, and inflammatory pathway dysfunction. These mechanisms involve genes such as PRSS1, PRSS2, SPINK, CEL, PNLIP, PNLIPRP2, CFTR, CaSR, CLDN2, Alpha 1 antitrypsin, and GGT1 . Studying genetic polymorphisms on the basis of altered genes and their products may aid clinicians in identifying predispositions in patients with and without common risk factors. Further research may also identify associations between genetic predispositions and disease staging or prognosis, leading to personalized treatment protocols and precision medicine.

Immune cells and immune cell-targeted therapy in chronic pancreatitis

In recent years, studies have attempted to understand the immune cells and mechanisms underlying the pathogenesis of chronic pancreatitis (CP) by constructing a model of CP. Based on these studies, the innate immune response is a key factor in disease pathogenesis and inflammation severity. Novel mechanisms of crosstalk between immune and non-immune pancreatic cells, such as pancreatic stellate cells (PSC), have also been explored. Immune cells, immune responses, and signaling pathways in CP are important factors in the development and progression of pancreatitis. Based on these mechanisms, targeted therapy may provide a feasible scheme to stop or reverse the progression of the disease in the future and provide a new direction for the treatment of CP. This review summarizes the recent advances in research on immune mechanisms in CP and the new advances in treatment based on these mechanisms.

Repeated Stimulation of Toll-Like Receptor 2 and Dectin-1 Induces Chronic Pancreatitis in Mice Through the Participation of Acquired Immunity

BACKGROUND

Stimulation of Toll-like receptor 3 (TLR3) induces autoimmune-mediated pancreatitis in susceptible mice, whereas stimulation of TLR4 causes nonautoimmune-mediated pancreatitis. However, the effects of TLR2 stimulation on the pancreas are unknown.

AIMS

We investigated the role of TLR2 stimulation on pancreatic damage by repeatedly stimulating mice with TLR2 ligands.

METHODS

Wild-type (WT) and interleukin 10-deficient (IL-10-knockout (KO)) mice were administered zymosan and lipoteichoic acid (LTA) intraperitoneally at various doses twice weekly for 4 weeks. Syngeneic T-cell-deficient mice, B-cell-deficient mice, recombination activating gene 2-deficient (RAG2-KO) mice and RAG2-KO mice that had been reconstituted with CD4⁺ or CD8⁺ T cells isolated from WT mice were treated with zymosan similarly. Mice were killed, the severity of pancreatitis was graded histologically, and serum cytokine levels were measured.

RESULTS

Repeated administration of zymosan induced pancreatitis dose dependently in both WT and IL-10-KO mice. Administration of LTA induced pancreatitis only in IL-10-KO mice. Adoptive transfer of splenocytes obtained from IL-10-KO mice with pancreatitis did not cause pancreatitis in recipient RAG2-KO mice. Pancreatitis was scarcely observed in RAG2-KO mice and was attenuated in T-cell-deficient and B-cell-deficient mice compared with WT mice. A single administration of zymosan significantly increased the serum level of monocyte chemoattractant protein 1 (MCP-1) in WT mice.

CONCLUSIONS

Repeated stimulation of TLR2 and dectin-1 induced nonautoimmune-mediated pancreatitis in mice. Participation of acquired immunity seems to play an important role in the pathogenesis of pancreatitis in association with the increase in serum MCP-1 level.

Endoscopic ultrasound-based multimodal evaluation of the pancreas in patients with suspected early chronic pancreatitis

BACKGROUND

Diagnosis of early chronic pancreatitis is a clinical challenge and hindered by the lack of a gold standard. Endoscopic ultrasound (EUS) and the endoscopic pancreatic function test (ePFT) are the most sensitive morphological and functional methods in this setting. EUS-elastography allows for the quantification (strain ratio) of pancreatic fibrosis, and the dynamic evaluation of the main pancreatic duct compliance provides additional information. We developed a multimodal EUS-based approach for the evaluation of the pancreas by integrating these four methods in a single procedure.

OBJECTIVE

We aim to describe morphological and functional pancreatic abnormalities in patients with clinical suspicion of chronic pancreatitis and inconclusive EUS findings by using the multimodal EUS-based approach.

METHODS

This was a prospective, cross-sectional, observational study of patients with clinically suspected chronic pancreatitis and indeterminate EUS criteria of the disease. EUS criteria of chronic pancreatitis, quantitative pancreatic elastography, ePFT and compliance of the main pancreatic duct were evaluated in a single procedure.

RESULTS

In total, 53 patients with 3-4 EUS criteria of chronic pancreatitis were included (mean age 39.7 years, 29 male). Strain ratio was abnormally high in all patients. Peak bicarbonate concentration was decreased in 43 patients (81.1%) and the main pancreatic duct compliance was reduced in 41 patients (77.3%). Some 34 patients (64.1%) had abnormal results at EUS, elastography, ePFT and compliance of the main pancreatic duct.

CONCLUSIONS

A multimodal EUS-based test for the morphological and functional evaluation of the pancreas is presented, which allows detecting mild pancreatic abnormalities in patients with suspected early chronic pancreatitis. The presence of abnormal morphological and functional evaluation of the pancreas could support the clinical suspicion of early chronic pancreatitis in the appropriate clinical setting.

Guidelines on the histopathology of chronic pancreatitis. Recommendations from the working group for the international consensus guidelines for chronic pancreatitis in collaboration with the International Association of Pancreatology, the American Pancreatic Association, the Japan Pancreas Society, and the European Pancreatic Club

BACKGROUND

Chronic pancreatitis is a complex multifactorial fibro-inflammatory disease. Consensus guidelines are needed for the histopathological evaluation of non-autoimmune chronic pancreatitis (CP).

METHODS

An international working group with experts on the histopathology of CP evaluated 15 statements generated from evidence on seven key clinically relevant questions. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the level of evidence available for each statement. To determine the level of agreement, the working group voted on the statements for strength of agreement, using a nine-point Likert scale, and Cronbach's alpha reliability coefficients were calculated.

RESULTS

Strong consensus was obtained for 12 statements relating to all seven key questions including that: the cardinal features of CP are the triad of fibrosis, loss of acinar tissue and duct changes; there are no unique histopathological features that distinguish the different aetiologies of CP; clinical history and laboratory investigations, including genetic testing, are important in establishing the aetiology of CP; there is no reproducible and universally accepted histological grading system for assessing severity of CP, although classification as "mild", "moderate" and "severe" is usually applied; scoring systems for fibrosis are not validated for clinical use; asymptomatic fibrosis is a common finding associated with ageing, and not necessarily evidence of CP; there are no obvious diagnostic macroscopic features of early CP; histopathology is not the gold standard for the diagnosis of CP; and cytology alone is not a reliable method for the diagnosis of CP.

CONCLUSIONS

Cardinal histopathological features of CP are well-defined and internationally accepted and pathological assessment is relevant for the purpose of differential diagnosis with other pancreatic diseases, especially cancer. However, a reliable diagnosis of CP requires integration of clinical, laboratory and imaging features and cannot be made by histology alone.

Diagnosis and Management of Chronic Pancreatitis: A Review

IMPORTANCE

Chronic pancreatitis (CP) is a chronic inflammatory and fibrotic disease of the pancreas with a prevalence of 42 to 73 per 100 000 adults in the United States.

OBSERVATIONS

Both genetic and environmental factors are thought to contribute to the pathogenesis of CP. Environmental factors associated with CP include alcohol abuse (odds ratio [OR], 3.1; 95% CI, 1.87-5.14) for 5 or more drinks per day vs abstainers and light drinkers as well as smoking (OR, 4.59; 95% CI, 2.91-7.25) for more than 35 pack-years in a case-control study involving 971 participants. Between 28% to 80% of patients are classified as having "idiopathic CP." Up to 50% of these individuals have mutations of the trypsin inhibitor gene (SPINK1) or the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Approximately 1% of people diagnosed with CP may have hereditary pancreatitis, associated with cationic trypsinogen (PRSS1) gene mutations. Approximately 80% of people with CP present with recurrent or chronic upper abdominal pain. Long-term sequelae include diabetes in 38% to 40% and exocrine insufficiency in 30% to 48%. The diagnosis is based on pancreatic calcifications, ductal dilatation, and atrophy visualized by imaging with computed tomography, magnetic resonance imaging, or both. Endoscopic ultrasound can assist in making the diagnosis in patients with a high index of suspicion such as recurrent episodes of acute pancreatitis when imaging is normal or equivocal. The first line of therapy consists of advice to discontinue use of alcohol and smoking and taking analgesic agents (nonsteroidal anti-inflammatory drugs and weak opioids such as tramadol). A trial of pancreatic enzymes and antioxidants (a combination of multivitamins, selenium, and methionine) can control symptoms in up to 50% of patients. Patients with pancreatic ductal obstruction due to stones, stricture, or both may benefit from ductal drainage via endoscopic retrograde cholangiopancreatography (ERCP) or surgical drainage procedures, such as pancreaticojejunostomy with or without pancreatic head resection, which may provide better pain relief among people who do not respond to endoscopic therapy.

CONCLUSIONS AND RELEVANCE

Chronic pancreatitis often results in chronic abdominal pain and is most commonly caused by excessive alcohol use, smoking, or genetic mutations. Treatment consists primarily of alcohol and smoking cessation, pain control, replacement of pancreatic insufficiency, or mechanical drainage of obstructed pancreatic ducts for some patients.

Chronic pancreatitis

Chronic pancreatitis is defined as a pathological fibro-inflammatory syndrome of the pancreas in individuals with genetic, environmental and/or other risk factors who develop persistent pathological responses to parenchymal injury or stress. Potential causes can include toxic factors (such as alcohol or smoking), metabolic abnormalities, idiopathic mechanisms, genetics, autoimmune responses and obstructive mechanisms. The pathophysiology of chronic pancreatitis is fairly complex and includes acinar cell injury, acinar stress responses, duct dysfunction, persistent or altered inflammation, and/or neuro-immune crosstalk, but these mechanisms are not completely understood. Chronic pancreatitis is characterized by ongoing inflammation of the pancreas that results in progressive loss of the endocrine and exocrine compartment owing to atrophy and/or replacement with fibrotic tissue. Functional consequences include recurrent or constant abdominal pain, diabetes mellitus (endocrine insufficiency) and maldigestion (exocrine insufficiency). Diagnosing early-stage chronic pancreatitis is challenging as changes are subtle, ill-defined and overlap those of other disorders. Later stages are characterized by variable fibrosis and calcification of the pancreatic parenchyma; dilatation, distortion and stricturing of the pancreatic ducts; pseudocysts; intrapancreatic bile duct stricturing; narrowing of the duodenum; and superior mesenteric, portal and/or splenic vein thrombosis. Treatment options comprise medical, radiological, endoscopic and surgical interventions, but evidence-based approaches are limited. This Primer highlights the major progress that has been made in understanding the pathophysiology, presentation, prevalence and management of chronic pancreatitis and its complications.

Long-term pain relief with optimized medical treatment including antioxidants and step-up interventional therapy in patients with chronic pancreatitis

BACKGROUND AND AIM

Abdominal pain is difficult to treat in patients with chronic pancreatitis (CP). Medical therapy including antioxidants has been shown to relieve pain of CP in the short-term. Our aim was to study the long-term results of optimized medical and interventional therapy for pain relief in patients with CP with a step-up approach.

METHODS

All consecutive patients with CP were included prospectively in the study. They were treated medically with a well-balanced diet, pancreatic enzymes, and antioxidants (9000 IU beta-carotene, 0.54 g vitamin C, 270 IU vitamin E, 600 µg organic selenium, and 2 g methionine). Endoscopic therapy and/or surgery were offered if medical therapy failed. Pain relief was the primary outcome measure.

RESULTS

A total of 313 patients (mean age 26.16 ± 12.17; 244 males) with CP were included; 288 (92%) patients had abdominal pain. The etiology of CP was idiopathic in 224 (71.6%) and alcohol in 82 (26.2%). At 1-year follow-up, significant pain relief was achieved in 84.7% of patients: 52.1% with medical therapy, 16.7% with endoscopic therapy, 7.6% with surgery, and 8.3% spontaneously. The mean pain score decreased from 6.36 ± 1.92 to 1.62 ± 2.10 (P < 0.001). Of the 288 patients, 261, 218, 112, and 51 patients were followed up for 3, 5, 10, and 15 years, respectively; 54.0%, 57.3%, 60.7%, and 68.8% of them became pain free at those follow-up periods.

CONCLUSION

Significant pain relief is achieved in the majority of patients with optimized medical and interventional treatment.

Caerulein-induced pancreatitis augments the expression and phosphorylation of collapsin response mediator protein 4

BACKGROUND

Chronic pancreatitis is a significant risk factor for pancreatic cancer. Previously, we demonstrated that the pancreatic cancer cells show enhanced expression of collapsin response mediator protein 4 (CRMP4) that strongly correlates with severe venous invasion, liver metastasis, and poor prognosis. However, involvement of CRMP4 in acute or chronic pancreatitis remains unknown.

METHODS

Acute and chronic pancreatitis mice models were developed by periodic injection of caerulein. The expression levels of CRMP4 and its phosphorylation were examined.

RESULTS

Elevated CRMP4 levels were observed in the infiltrated lymphocytes as well as in the pancreas parenchyma of both acute and chronic pancreatitis. The expression pattern of phosphorylated CRMP4 was similar to that of CRMP4. Cdk5 partially co-localized with the phosphorylated CRMP4.

CONCLUSIONS

Pancreatitis induces CRMP4 expression in the pancreas parenchyma and in the infiltrated lymphocytes. Overlapping expression of CRMP4 and Cdk5 may suggest that the Cdk5 is at least, in part, responsible for the phosphorylation of CRMP4. The results suggest that CRMP4 is involved in the inflammatory response in pancreatitis. Understanding the mechanisms of CRMP4 would help us to develop novel therapeutic strategies against acute or chronic pancreatitis, and pancreatic cancer.

Current understanding of the neuropathophysiology of pain in chronic pancreatitis

Chronic pancreatitis (CP) is a chronic inflammatory disease of the pancreas. The main symptom of patients with CP is chronic and severe abdominal pain. However, the pathophysiology of pain in CP remains obscure. Traditionally, researchers believed that the pain was caused by anatomical changes in pancreatic structure. However, treatment outcomes based on such beliefs are considered unsatisfactory. The emerging explanations of pain in CP are trending toward neurobiological theories. This article aims to review current evidence regarding the neuropathophysiology of pain in CP and its potential implications for the development of new treatments for pain in CP.

Bone morphogenetic protein signaling protects against cerulein-induced pancreatic fibrosis

Bone morphogenetic proteins (BMPs) have an anti-fibrogenic function in the kidney, lung, and liver. However, their role in chronic pancreatitis (CP) is unknown. The aim of this study was to define the anti-fibrogenic role of BMP signaling in the pancreas in vivo under CP induction. Mice with a deletion of BMP type II receptor (BMPR2^+/−) were used in this study in comparison with wild-type mice. CP was induced by repetitive cerulein injection intraperitoneally for 4 weeks, and the severity of CP was evaluated. Pancreatic stellate cells (PSCs) were isolated from the mice and treated with BMP2 and TGF-β in vitro, and extracellular matrix protein (ECM) production was measured. Smad and mitogen-activated protein kinase (MAPK) signaling was also evaluated. BMPR2^+/− mice revealed a greater pancreatic fibrosis, PSC activation and leukocyte infiltration after CP induction compared to wild-type mice (P<0.05). Under CP induction, phospho (p)Smad1/5/8 was elevated in wild-type mice and this effect was abolished in BMPR2^+/− mice; pSmad2 and pp38^MAPK were further enhanced in BMPR2^+/− mice compared to wild-type mice (P<0.05). In vitro, BMP2 inhibited TGF-β-induced ECM protein fibronectin production in wild-type PSCs; this effect was abolished in BMPR2^+/− PSCs (P<0.05). In BMPR2^+/− PSCs, pSmad1/5/8 level was barely detectable upon BMP2 stimulation, while pSmad2 level was further enhanced by TGF-β stimulation, compared to wild-type PSCs (P<0.05). BMPR2/Smad1/5/8 signaling plays a protective role against cerulein-induced pancreatic fibrosis by inhibiting Smad2 and p38^MAPK signaling pathways.

Risk factors for pancreatic cancer: underlying mechanisms and potential targets

PURPOSE OF THE REVIEW

Pancreatic cancer is extremely aggressive, forming highly chemo-resistant tumors, and has one of the worst prognoses. The evolution of this cancer is multi-factorial. Repeated acute pancreatic injury and inflammation are important contributing factors in the development of pancreatic cancer. This article attempts to understand the common pathways linking pancreatitis to pancreatic cancer.

RECENT FINDINGS

Intracellular activation of both pancreatic enzymes and the transcription factor NF-κB are important mechanisms that induce acute pancreatitis (AP). Recurrent pancreatic injury due to genetic susceptibility, environmental factors such as smoking, alcohol intake, and conditions such as obesity lead to increases in oxidative stress, impaired autophagy and constitutive activation of inflammatory pathways. These processes can stimulate pancreatic stellate cells, thereby increasing fibrosis and encouraging chronic disease development. Activation of oncogenic Kras mutations through inflammation, coupled with altered levels of tumor suppressor proteins (p53 and p16) can ultimately lead to development of pancreatic cancer.

SUMMARY

Although our understanding of pancreatitis and pancreatic cancer has tremendously increased over many years, much remains to be elucidated in terms of common pathways linking these conditions.

Acquired immunity plays an important role in the development of murine experimental pancreatitis induced by alcohol and lipopolysaccharide

OBJECTIVE

Although chronic alcohol ingestion is the major cause of chronic pancreatitis, less than 10% of alcohol abusers develop this disease. To address this issue, we created a murine model of pancreatitis induced by alcohol and lipopolysaccharide (LPS) and analyzed its immune responses.

METHODS

C57BL/6 mice were administered 20% ethanol (AL) in their drinking water and then injected intraperitoneally with LPS twice weekly for 4 weeks. Severe combined immunodeficient mice were reconstituted with splenocytes, CD4 cells, or CD8 T cells isolated from wild-type mice and then treated similarly. The severity of pancreatitis was graded histologically, and serum cytokine levels were measured.

RESULTS

Ethanol alone did not cause pancreatitis. However, the administration of AL+LPS or LPS alone induced pancreatitis. The histological scores were higher in the mice treated with AL+LPS than in those treated with LPS. Serum levels of interleukin 1β, interferon-γ, and tumor necrosis factor α were elevated in the AL+LPS-treated mice. The severe combined immunodeficient mice developed pancreatitis only after their reconstitution with splenocytes, CD4 cells, or CD8 T cells.

CONCLUSIONS

Repeated stimulation of the innate immune system is necessary, but not sufficient, to cause pancreatitis. The participation of the acquired immune response is essential for the development of the disease.

Cerulein-induced chronic pancreatitis does not require intra-acinar activation of trypsinogen in mice

BACKGROUND & AIMS

Premature activation of trypsinogen activation can cause pancreatic injury and has been associated with chronic pancreatitis (CP). Mice that lack intra-acinar activation of trypsinogen, such as trypsinogen-7-null (T(-/-)) and cathepsin B-null (CB(-/-)) mice, have been used to study trypsin-independent processes of CP development. We compared histologic features and inflammatory responses of pancreatic tissues from these mice with those from wild-type mice after the development of CP.

METHODS

CP was induced in wild-type, T(-/-), and CB(-/-) mice by twice-weekly induction of acute pancreatitis for 10 weeks; acute pancreatitis was induced by hourly intraperitoneal injections of cerulein (50 μg/kg × 6). Pancreatic samples were collected and evaluated by histologic and immunohistochemical analyses. Normal human pancreas samples, obtained from the islet transplant program at the University of Minnesota, were used as controls and CP samples were obtained from surgical resections.

RESULTS

Compared with pancreatic tissues from wild-type mice, those from T(-/-) and CB(-/-) mice had similar levels of atrophy, histomorphologic features of CP, and chronic inflammation. All samples had comparable intra-acinar activation of nuclear factor (NF)-κB, a transcription factor that regulates the inflammatory response, immediately after injection of cerulein. Pancreatic tissue samples from patients with CP had increased activation of NF-κB (based on nuclear translocation of p65 in acinar cells) compared with controls.

CONCLUSIONS

Induction of CP in mice by cerulein injection does not require intra-acinar activation of trypsinogen. Pancreatic acinar cells of patients with CP have increased levels of NF-κB activation compared with controls; regulation of the inflammatory response by this transcription factor might be involved in the pathogenesis of CP.

What is personalized medicine and what should it replace?

Personalized medicine is a new framework for medical care that involves modelling and simulation of a disease on the basis of its underlying mechanisms. This strategy must replace the 20(th) century paradigm of defining disease by pathology or associated signs and symptoms and conducting outcomes research that is based on the presence or absence of the disease syndrome. New technologies, including next-generation sequencing, the 'omics' and powerful computers provide massive amounts of accurate data. However, attempts to understand complex disorders by applying these new technologies within the 20(th) century framework have failed to produce the expected medical advances. To help physicians embrace a paradigm shift, the limitations of the old framework and major advantages of the new framework must be demonstrated. Chronic pancreatitis is an ideal complex disorder to study to consider the pros and cons of the two frameworks, because the pancreas is such a simple organ for disease modelling, and the advantages of personalized medicine are so profound.

Genetics of pancreatitis

PURPOSE OF REVIEW

Chronic pancreatitis is a syndrome characterized by chronic inflammation of the pancreas, with variable pain, calcifications, necrosis, fatty replacement, fibrosis and scarring and other complications. Disease susceptibility, severity, progression and pain patterns vary widely and do not necessarily parallel one another. Much of the variability in susceptibility to recurrent acute and chronic pancreatitis is now clearly shown to be related to genetic differences between patients. This review highlights recent advances and future directions in genetic research.

RECENT FINDINGS

The strongest risk factors are associated with genetic variations in PRSS1, SPINK1, CFTR, and to a lesser extent, CTRC and CASR. The latest research suggest that a single factor rarely causes pancreatitis, and the majority of patients with recurrent acute and chronic pancreatitis have multiple variants in a gene, or epistatic interactions between multiple genes, coupled with environmental stressors.

SUMMARY

Pancreatic diseases have a strong genetic component. Rather than a classic Mendelian disorder, recurrent acute and chronic pancreatitis represents truly complex diseases with the interaction and synergism of multiple genetic and environmental factors. The future will require new predictive models to guide prevention and therapy.

Chronic pancreatitis

Chronic pancreatitis is a progressive fibroinflammatory disease that exists in large-duct (often with intraductal calculi) or small-duct form. In many patients this disease results from a complex mix of environmental (eg, alcohol, cigarettes, and occupational chemicals) and genetic factors (eg, mutation in a trypsin-controlling gene or the cystic fibrosis transmembrane conductance regulator); a few patients have hereditary or autoimmune disease. Pain in the form of recurrent attacks of pancreatitis (representing paralysis of apical exocytosis in acinar cells) or constant and disabling pain is usually the main symptom. Management of the pain is mainly empirical, involving potent analgesics, duct drainage by endoscopic or surgical means, and partial or total pancreatectomy. However, steroids rapidly reduce symptoms in patients with autoimmune pancreatitis, and micronutrient therapy to correct electrophilic stress is emerging as a promising treatment in the other patients. Steatorrhoea, diabetes, local complications, and psychosocial issues associated with the disease are additional therapeutic challenges.

Feasibility of EUS-guided injection of irinotecan-loaded microspheres into the swine pancreas

BACKGROUND

LC beads (Biocompatibles International plc) are designed for the time-released delivery of the chemotherapeutic agent irinotecan into focal, hypervascularized, hepatic tumors.

OBJECTIVE

To determine the feasibility of EUS-guided injection of LC beads (with/without irinotecan) into the swine pancreas.

DESIGN

Survival animal study.

SETTING

Academic center.

SUBJECTS

This study involved 12 Yorkshire swine.

INTERVENTION

LC beads without irinotecan and loaded with up to 300 mg of irinotecan were injected under EUS guidance with a 19-gauge needle into the tail of the pancreas. CT scanning and necropsy with histology were performed at day 7.

MAIN OUTCOME MEASUREMENTS

Feasibility of the injections, gross and microscopic evidence of pancreatic inflammation, and clinical tolerance by the animals.

RESULTS

After injection of LC beads with/without irinotecan, in 10 of 12 animals an intrapancreatic, hyperechoic focus with an average diameter of 2.2 cm was visible by EUS, and a hypodense area in the tail of the pancreas was visible by contrast CT. In 2 animals (1 with irinotecan and 1 without) no beads were seen on CT. In 10 of 12 animals, a depot of beads was located in the tail of the pancreas on gross inspection and histology. Drug depot with only localized pancreatic tissue reactions was seen on histopathologic review.

LIMITATIONS

Animal study.

CONCLUSION

The EUS-guided injection of LC beads (with/without irinotecan) into the pancreas of the pig is feasible and safe. This technique is a potential minimally invasive local treatment option for locally advanced pancreatic cancer.

Combined bicarbonate conductance-impairing variants in CFTR and SPINK1 variants are associated with chronic pancreatitis in patients without cystic fibrosis

BACKGROUND & AIMS

Idiopathic chronic pancreatitis (ICP) is a complex inflammatory disorder associated with multiple genetic and environmental factors. In individuals without cystic fibrosis (CF), variants of CFTR that inhibit bicarbonate conductance but maintain chloride conductance might selectively impair secretion of pancreatic juice, leading to trypsin activation and pancreatitis. We investigated whether sequence variants in the gene encoding the pancreatic secretory trypsin inhibitor SPINK1 further increase the risk of pancreatitis in these patients.

METHODS

We screened patients and controls for variants in SPINK1 associated with risk of chronic pancreatitis and in all 27 exons of CFTR. The final study group included 53 patients with sporadic ICP, 27 probands with familial ICP, 150 unrelated controls, 375 additional controls for limited genotyping. CFTR wild-type and p.R75Q were cloned and expressed in HEK293 cells, and relative conductances of HCO(3)(-) and Cl(-) were measured.

RESULTS

SPINK1 variants were identified in 36% of subjects and 3% of controls (odds ratio [OR], 18.1). One variant of CFTR not associated with CF, p.R75Q, was found in 16% of subjects and 5.3% of controls (OR, 3.4). Coinheritance of CFTR p.R75Q and SPINK1 variants occurred in 8.75% of patients and 0.38% of controls (OR, 25.1). Patch-clamp recordings of cells that expressed CFTR p.R75Q showed normal chloride currents but significantly reduced bicarbonate currents (P = .0001).

CONCLUSIONS

The CFTR variant p.R75Q causes a selective defect in bicarbonate conductance and increases risk of pancreatitis. Coinheritance of p.R75Q or CF causing CFTR variants with SPINK1 variants significantly increases the risk of ICP.

The prevalence of cationic trypsinogen (PRSS1) and serine protease inhibitor, Kazal type 1 (SPINK1) gene mutations in Polish patients with alcoholic and idiopathic chronic pancreatitis

BACKGROUND

The main cause of chronic pancreatitis (CP) is excessive alcohol consumption. On the other hand, only 5-10% of heavy drinkers develop chronic pancreatitis. We have only limited information regarding the pathogenic mechanism by which alcohol leads to the disease. Mutations of the PRSS1 and SPINK 1 have been mostly implicated in hereditary and idiopathic CP, but their presence in other types of this disease have also been reported.

AIMS

The aim of the study was to determine the frequency of PRSS1 and SPINK1 mutations in patients with chronic alcoholic (ACP) and idiopathic pancreatitis (ICP) as well as to investigate their relation to the clinical course of the disease.

METHODS

The study included 33 ACP and 14 ICP patients as well 46 healthy subjects. The diagnosis of CP was based on clinical data, ultrasound, and computed tomography. After isolation of DNA from peripheral blood two trypsinogen mutations were detected N29I and R122H by allelo-specific amplification polymerase chain reaction (ASA-PCR) and by the PCR-restriction fragment length polymorphism (RFLP). Beside this N34S mutation of SPINK1 was analyzed by PCR restriction fragment length polymorphism (PCR-RFLP).

RESULTS

PRSS1 mutations have been detected in 11 (33%) patients with ACP. The frequency of the PRSS1 mutations was higher in patients with ACP than in controls (4.3%) (p < 0.001). The frequency of PRSS1 mutation was present in 21.4% of ICP patients, which was significantly higher (p < 0.05) than in controls. Overall, six (18%) SPINK1 mutations in ACP group have been detected. Among 14 patients with ICP, in four (28.6%) of them SPINK1 has been detected. The same mutations have also been found in three (6.5%) control subjects. The frequency of the N34S mutation was higher in patients with ICP than in the controls (p < 0.05), but the frequency of N34S mutation did not differ between ACP and the control group. No relations have been detected between PRSS1 and SPINK1 mutations presence and clinical course and complications of CP.

CONCLUSIONS

Those preliminary data suggest the high prevalence of SPINK1 and PRSS1 mutations in the Polish population, generally, as well as in CP patients. It may be speculated that those mutations contribute to the development of chronic pancreatitis, especially in patients with alcohol overindulgence.

The role of alcohol and smoking in pancreatitis

Chronic alcohol use has been linked to chronic pancreatitis for over a century, but it has not been until the last decade that the role of alcohol in chronic pancreatitis has been elucidated in animals and, only in recent years, in human populations. Although a dose-dependent association between alcohol consumption and chronic pancreatitis may exist, a staistical association has been shown only with the consumption of >or=5 alcoholic drinks per day. Smoking also confers a strong, independent and dose-dependent risk of pancreatitis that may be additive or multiplicative when combined with alcohol. Alcohol increases the risk of acute pancreatitis in several ways and, most importantly, changes the immune response to injury. Genetic factors are also important and further studies are needed to clarify the role of gene-environment interactions in pancreatitis. In humans, aggressive interventional counseling against alcohol use may reduce the frequency of recurrent attacks of disease and smoking cessation may help to slow the progression of acute to chronic pancreatitis.

A proposal for a new clinical classification of chronic pancreatitis

BACKGROUND

The clinical course of chronic pancreatitis is still unpredictable, which relates to the lack of the availability of a clinical classification. Therefore, patient populations cannot be compared, the course and the outcome of the disease remain undetermined in the individual patient, and treatment is not standardized.

AIM

To establish a clinical classification for chronic pancreatitis which is user friendly, transparent, relevant, prognosis- as well as treatment-related and offers a frame for future disease evaluation.

METHODS

Diagnostic requirements will include one clinical criterion, in combination with well defined imaging or functional abnormalities.

RESULTS

A classification system consisting of three stages (A, B and C) is presented, which fulfils the above-mentioned criteria. Clinical criteria are: pain, recurrent attacks of pancreatitis, complications of chronic pancreatitis (e.g. bile duct stenosis), steatorrhea, and diabetes mellitus. Imaging criteria consist of ductal or parenchymal changes observed by ultrasonography, ERCP, CT, MRI, and/or endosonography.

CONCLUSION

A new classification of chronic pancreatitis, based on combination of clinical signs, morphology and function, is presented. It is easy to handle and an instrument to study and to compare the natural course, the prognosis and treatment of patients with chronic pancreatitis.

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.

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.

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.

Mechanisms and natural history of pain in chronic pancreatitis: a surgical perspective

Pain is a major clinical manifestation of chronic pancreatitis (CP) and a common indication for surgery in these patients. Pathogenesis of pain in CP is multifactorial and the mechanisms of pain may differ from patient to patient. This can explain why one therapeutic method of treatment of pain does not work in all patients and in different stages of the disease. Two main complimentary pathogenetic theories have been proposed to explain the mechanisms of pain in CP, the neurogenic theory and the theory of increased intraductal/intraparenchymal pressures. According to the neurogenic theory, in CP there are alterations of pancreatic/peripancreatic nerves, exposing them to noxious substances and/or activated immune cells, thereby generating pain ("neuroimmune interaction"). The other theory of intraductal/intraparenchymal hypertension suggests that pain in CP is generated as a result of increased pressures within the pancreatic ductal system and/or pancreatic parenchyma, like the pain in the classic compartment syndrome. The theory of intraductal/intraparenchymal hypertension is strongly supported by the good results of drainage procedures in the surgical management of CP. Pancreatic ischemia, oxygen-free radicals, centrally sensitized pain state, acute exacerbations of CP, development of complications from the pancreas (most commonly, pseudocysts) or adjacent organs (usually, duodenal and/or common bile duct stenosis), etc. are other possible contributing factors. Different patterns of pain have been described in idiopathic (early vs. late onset) and in alcoholic CP. Interestingly, pain is automatically relieved during the natural course of the disease in some patients (the "burn-out" phenomenon), after a relatively long time (from a few years to up to 3 decades). However, this is an unpredictable evolution for the individual patient. Therefore, surgery should be offered when pain is intense and after failure of conservative treatment. Surgical management should be individualized, depending on the particular findings of each patient. The knowledge of the pathophysiologic basis and of natural course of pain in CP is of paramount importance for the surgeon to select appropriate therapy for the individual patient with CP.

Prevalence and histopathologic characteristics of pancreatitis in cats

Despite the high prevalence of feline pancreatic disease, no detailed description on the histopathologic nature of this disease is currently available in the literature. In this study we characterize the distribution and histopathologic changes commonly found in feline pancreases, correlate the lesions with age and gastrointestinal GI and extra-gastrointestinal disease, and compare the pancreatic lesions in cats with those in humans. The entire pancreas was removed and examined from 115 cats presented for necropsy irrespective of the cause of death. Histologic sections from left limb, right limb, and body were scored for lesions of acute (AP) and chronic pancreatitis (CP) with a scoring system based on similar systems used in human and veterinary literature. The lesions of CP in cats resemble CP in humans, with fibrosis being more prominent than inflammatory changes. Cystic degeneration gradually increased as other lesions of CP were more prominent. A distinct nodular change of zymogen depletion and acinar cell dysplasia not associated with pancreatitis was prominent in 15.6% of the pancreases. Histologically, AP consisted of neutrophilic inflammation associated with interstitial edema and necrosis of mesenteric fat. An overall prevalence of 67%, and 45% in clinically normal animals, was identified. CP was found in 69 (60.0%) pancreases, and 58 (50.4%) had CP only, with a significant correlation between age and occurrence of CP. There was a statistically significant higher prevalence of CP in the left limb in animals with gastrointestinal disease. AP was present in 18 animals (15.7%) of which 7 animals had AP only (6.1%).

The ECM proteoglycan decorin links desmoplasia and inflammation in chronic pancreatitis

BACKGROUND

Recurrent inflammation in chronic pancreatitis (CP) is not well understood.

AIMS

To investigate whether decorin, an extracellular matrix (ECM) proteoglycan with macrophage modulating activity, is a pathogenic factor allowing diseased pancreatic stroma to sustain inflammation by affecting the cytokine profile of accumulating inflammatory cells.

METHODS

Decorin was examined in 18 donors and 32 patients with CP by quantitative reverse transcription polymerase chain reaction (QRT-PCR), western blotting, and immunohistochemistry of pancreatic specimens. QRT-PCR was used to assess cytokine expression in donor peripheral blood mononuclear cells (PBMC), exposed or not to decorin in vitro, and to compare it with the cytokine profile of circulating and resident mononuclear cells (MNC) of patients with CP.

RESULTS

In CP, desmoplasia is associated with overexpression of decorin in the growing ECM and enlarged pancreatic nerves. In culture, exposure of MNC to decorin stimulated expression of the MNC recruiting chemokine MCP-1. In biopsies, MNC infiltrates in decorin rich CP tissue showed a 300-fold upregulation of MCP-1 compared with decorin free peripheral blood, whereas no difference was found in basal MCP-1 expression in PBMC of patients versus donors. This effect was specific for MCP1-other inflammatory cytokines, such as interleukin 1beta and tumour necrosis factor alpha, were not affected.

CONCLUSION

Decorin is a molecular marker of desmoplasia in CP, and excessive decorin may allow fibrotic masses to nourish and protract inflammation by deregulating the process of MNC accumulation and activation. These data provide a molecular basis for surgical resection of diseased tissue as a treatment option in CP.

Mechanisms of disease: Advances in understanding the mechanisms leading to chronic pancreatitis

Chronic pancreatitis remains a challenging and frustrating clinical problem. In the past few years, however, advances in genetic and immunologic research have spawned new insights and approaches to chronic pancreatitis. Genetic and environmental risk assessment may help identify individuals who are likely to develop severe chronic pancreatitis early in the disease course, and allow targeted attention to reduce confounding risks and slow or prevent this problem in the future.

Mutations N34S and P55S of the SPINK1 gene in patients with chronic pancreatitis or pancreatic cancer and in healthy subjects: a report from Finland

OBJECTIVE

Mutations in the Kazal type 1 serine protease inhibitor (SPINK1) gene have recently been associated with chronic pancreatitis (CP), an established risk factor for pancreatic cancer. The aim of this study was to investigate the frequency of the SPINK1 gene mutations (N34S and P55S) in patients with CP, or pancreatic cancer, and in healthy subjects in Finland.

MATERIAL AND METHODS

The N34S and P55S mutations were determined by PCR amplification followed by solid-phase minisequencing in 116 patients with CP and in 188 with pancreatic cancer. In patients with CP, alcohol was the aetiological factor in 87 (75%), pancreas divisum in 4 (3%), gallstones in 5 (5%) and 20 patients (17%) had an idiopathic disease; 459 healthy individuals were enrolled as controls.

RESULTS

The frequency of the N34S mutation was significantly higher in patients with CP (14/116, 12%) than in controls (12/459, 2.6%) (p<0.0001). There was no difference in the frequency of the P55S mutation between patients with CP (1/116, 0.9%) and controls (6/459, 1.3%). The N34S mutation was present in 9 (10%) out of 87 patients with alcoholic CP, and in 5 (25%) patients with idiopathic CP. No SPINK1 mutations were found in patients with CP caused by anatomical variations or gallstones. Among the 188 patients with a pancreatic malignant tumour, the N34S mutation was present in 7 cases (3.7%). The frequency of the N34S mutation in healthy controls in this study was significantly higher than earlier reported in other countries (p=0.03).

CONCLUSIONS

The SPINK1 N34S mutation was significantly associated with an increased risk of CP. The association of the N34S mutation with alcoholic CP was marginally stronger than in earlier studies, whereas in the Finnish population in general, this mutation was significantly more frequent than reported elsewhere.

Theories, mechanisms, and models of alcoholic chronic pancreatitis

Alcoholic chronic pancreatitis is a severe, disabling, chronic inflammatory condition of the pancreas that is seen in fewer than 5% of alcoholics. The severity and unpredictability of this condition has lead to several theories on the mechanism causing chronic pancreatitis based on careful clinical observation. Hypothetical mechanisms were applied to various animal models. Finally, following multiple lines of evidence, there is a convergence of thought and development of some new models that are quite instructive. Taken together, chronic alcohol consumption by rats results in multiple effects on the pancreas that increase the risk of acute pancreatitis, including ongoing acinar cell injury that lowers the threshold for hyperstimulation-induced acute pancreatitis, neurohormonal injury, and adaptation that results in acinar cell hyperstimulation, increased susceptibility to viral mediated acute pancreatitis, and possibly other factors. After acute pancreatitis initiates the inflammatory process, the chronic inflammation and fibrosis of alcoholic chronic pancreatitis are driven by diet, the acinar cell stress response to continued alcohol that may be potentiated by toxic alcohol metabolites, hypoxia, hyperstimulation, and partial duct obstruction; plus the effects of proinflammatory immunocytes and cytokines; and by stellate cell-mediated fibrosis driven by anti-inflammatory cytokines, alcohol, and alcohol metabolites. The factors determining which alcoholic will develop alcoholic chronic pancreatitis likely involve genetic factors, dietary factors, and susceptibility to pancreatic injury through several mechanisms ranging from trauma to gallstones to viruses.