The early diagnosis of chronic pancreatitis

Assessment of exocrine pancreatic function in children and adolescents with direct and indirect testing

The exocrine pancreas plays an important role in digestion. Understanding of the physiology and regulation of exocrine function provides insight into disease processes and basis of functional testing. Specifically, exocrine pancreatic insufficiency (EPI) can cause maldigestion and thus a proper assessment of exocrine pancreatic function is important. There are indirect and direct methods for evaluating pancreatic function. Indirect methods are varied and include stool, serum, urine, and breath tests. Fecal elastase is a commonly used indirect test today. Direct methods involve stimulated release of pancreatic fluid that is collected from the duodenum and analyzed for enzyme activity. The most used direct test today is the endoscopic pancreatic function test. Indirect pancreatic function testing is limited in identifying cases of mild to moderate EPI, and as such in these cases, direct testing has higher sensitivity and specificity in diagnosing EPI. This review provides a comprehensive guide to indirect and direct pancreatic function tests as well as an in-depth look at exocrine pancreatic function including anatomy, physiology, and regulatory mechanisms.

Pancreatic Fibrosis (Early Chronic Pancreatitis) as Emerging Diagnosis in Structural Causes of Dyspepsia: Evidence from Endoscopic Ultrasonography and Shear Wave Elastography

A new concept for the diagnosis and management of non-functional dyspepsia in guidelines was lacking in the past decade. Medical advancement has proven pancreatic fibrosis (essential image evidence of early chronic pancreatitis) to be a cause of dyspepsia and related to pancreatic exocrine dysfunction. This study aimed to analyze the clinical picture, biomarker, and percentage of pancreatic fibrosis in the dyspeptic population. A total of 141 consecutive patients were retrospectively enrolled. They were diagnosed with peptic ulcer disease, 9.2% (n = 13); pancreatic fibrosis, 17% (n = 24); pure Helicobacter pylori infection, 19.9% (n = 28); functional dyspepsia, 53.2% (n = 75); and chronic pancreatitis, 0.7% (n = 1). Among those with pancreatic fibrosis, (n = 24), 11 were diagnosed on the basis of a pancreatic acoustic radiation force impulse exceeding 1.4 m/s, and the remaining 13 were diagnosed with early chronic pancreatitis with at least three of the Japanese endoscopic ultrasonography criteria. The anatomic distribution of parenchymal criteria of early chronic pancreatitis was head, 53%; body, 38%; and tail, 9%. There were 17 cases (71%, 17/24) without Helicobacter pylori and whose dyspepsia improved after pancreatic enzyme replacement with a ratio of 82.3% (14/17). Of the 141 cases, 19 received gastric emptying scintigraphy and Western blot analysis of chromogranin-A in duodenal mucosa. Delayed gastric emptying was more common in functional dyspepsia and chromogranin-A was expressed more in pancreatic fibrosis. In conclusion, pancreatic fibrosis (including early chronic pancreatitis) outnumbered peptic ulcer disease in the dyspeptic population and pancreatic enzyme therapy was effective for 82% of cases. In early chronic pancreatitis, pancreatic fibrosis is dominant in the head location, and duodenum mucosa chromogranin-A is a potential biomarker with increased expression in an age-matched manner.

Biomarkers of Chronic Pancreatitis: A systematic literature review

BACKGROUND

Chronic pancreatitis (CP) does not have diagnostic or prognostic biomarkers. CP is the end stage of a progressive inflammatory syndrome that is diagnosed at late stages by morphologic features. To diagnose earlier stages of the disease, a new mechanistic definition was established based on identifying underlying pathogenic processes and biomarker evidence of disease activity and stage. Although multiple risk factors are known, the corresponding biomarkers needed to make a highly accurate diagnosis of earlier disease stages have not been established. The goal of this study is to systematically analyze the literature to identify the most likely candidates for development into biomarkers of CP.

METHODS

We conducted a systematic review of candidate analytes from easily accessible biological fluids and identified 67 studies that compared CP to nonpancreatic-disease controls. We then ranked candidate biomarkers for sensitivity and specificity by area under the receiver operator curves (AUROCs).

RESULTS

Five biomarkers had a large effect size (an AUROC > 0.96), whereas 30 biomarkers had a moderate effect size (an AUROC between 0.96 and 0.83) for distinguishing CP cases from controls or other diseases. However, the studies reviewed had marked variability in design, enrollment criteria, and biospecimen sample handling and collection.

CONCLUSIONS

Several biomarkers have the potential for evaluation in prospective cohort studies and should be correlated with risk factors, clinical features, imaging studies and outcomes. The Consortium for the Study of Chronic Pancreatitis, Diabetes and Pancreas Cancer provides recommendations for avoiding design biases and heterogeneity in sample collection and handling in future studies.

Delayed Processing of Secretin-Induced Pancreas Fluid Influences the Quality and Integrity of Proteins and Nucleic Acids

OBJECTIVES

Endoscopic pancreatic function tests are used to diagnose pancreatic diseases and are a viable source for the discovery of biomarkers to better characterize pancreatic disorders. However, pancreatic fluid (PF) contains active enzymes that degrade biomolecules. Therefore, we tested how preservation methods and time to storage influence the integrity and quality of proteins and nucleic acids.

METHODS

We obtained PF from 9 subjects who underwent an endoscopic pancreatic function test. Samples were snap frozen at the time of collection; after 1, 2, and 4 hours on ice; or after storage overnight at 4°C with or without RNase or protease inhibitors (PIs). Electrophoresis and mass spectrometry analysis determined protein abundance and quality, whereas nucleic acid integrity values determined DNA and RNA degradation.

RESULTS

Protein degradation increased after 4 hours on ice and DNA degradation after 2 hours on ice. Adding PIs delayed degradation. RNA was significantly degraded under all conditions compared with the snap frozen samples. Isolated RNA from PF-derived exosomes exhibited similar poor quality as RNA isolated from matched PF samples.

CONCLUSIONS

Adding PIs immediately after collecting PF and processing the fluid within 4 hours of collection maintains the protein and nucleic acid integrity for use in downstream molecular analyses.

Advanced imaging techniques for chronic pancreatitis

MRI and MRCP play an important role in the diagnosis of chronic pancreatitis (CP) by imaging pancreatic parenchyma and ducts. MRI/MRCP is more widely used than computed tomography (CT) for mild to moderate CP due to its increased sensitivity for pancreatic ductal and gland changes; however, it does not detect the calcifications seen in advanced CP. Quantitative MR imaging offers potential advantages over conventional qualitative imaging, including simplicity of analysis, quantitative and population-based comparisons, and more direct interpretation of detected changes. These techniques may provide quantitative metrics for determining the presence and severity of acinar cell loss and aid in the diagnosis of chronic pancreatitis. Given the fact that the parenchymal changes of CP precede the ductal involvement, there would be a significant benefit from developing MRI/MRCP-based, more robust diagnostic criteria combining ductal and parenchymal findings. Among cross-sectional imaging modalities, multi-detector CT (MDCT) has been a cornerstone for evaluating chronic pancreatitis (CP) since it is ubiquitous, assesses primary disease process, identifies complications like pseudocyst or vascular thrombosis with high sensitivity and specificity, guides therapeutic management decisions, and provides images with isotropic resolution within seconds. Conventional MDCT has certain limitations and is reserved to provide predominantly morphological (e.g., calcifications, organ size) rather than functional information. The emerging applications of radiomics and artificial intelligence are poised to extend the current capabilities of MDCT. In this review article, we will review advanced imaging techniques by MRI, MRCP, CT, and ultrasound.

Magnetic resonance imaging as a non-invasive method for the assessment of pancreatic fibrosis (MINIMAP): a comprehensive study design from the consortium for the study of chronic pancreatitis, diabetes, and pancreatic cancer

Characteristic features of chronic pancreatitis (CP) may be absent on standard imaging studies. Quantitative Magnetic Resonance Imaging (MRI) techniques such as T1 mapping, extracellular volume (ECV) fraction, diffusion-weighted imaging (DWI) with apparent diffusion coefficient map (ADC), MR elastography (MRE), and T1-weighted signal intensity ratio (SIR) have shown promise for the diagnosis and grading severity of CP. However, radiologists still use the Cambridge classification which is based on traditional ductal imaging alone. There is an urgent need to develop new diagnostic criteria that incorporate both parenchymal and ductal features of CP seen by MRI/MRCP. Designed to fulfill this clinical need, we present the MINIMAP study, which was funded in September 2018 by the National Institutes of Health. This is a comprehensive quantitative MR imaging study which will be performed at multiple institutions in well-phenotyped CP patient cohorts. We hypothesize that quantitative MRI/MRCP features can serve as valuable non-invasive imaging biomarkers to detect and grade CP. We will evaluate the role of T1 relaxometry, ECV, T1-weighted gradient echo SIR, MRE, arteriovenous enhancement ratio, ADC, pancreas volume/atrophy, pancreatic fat fraction, ductal features, and pancreatic exocrine output following secretin stimulation in the assessment of CP. We will attempt to generate a multi-parametric pancreatic tissue fibrosis (PTF) scoring system. We anticipate that a quantitative scoring system may serve as a biomarker of pancreatic fibrosis; hence this imaging technique can be used in clinical practice as well as clinical trials to evaluate the efficacy of agents which may slow the progression or reverse measures of CP.

Assessment of Exocrine Pancreatic Function During Endoscopy in Children

This article will review briefly the physiology of pancreatic enzyme secretion and the role of stimulated endoscopic testing for assessing exocrine pancreatic function. Published studies in both the pediatric and adult literature are reviewed. The technique and utility of endoscopic pancreatic function testing as the method of choice in the differential diagnosis of pancreatic disorders in childhood is described. Finally, emerging, clinically useful markers that can be measured in the pancreatic fluid will be described.

Alcohol-related chronic exocrine pancreatic insufficiency: diagnosis and therapeutic management. A proposal for treatment by the Italian Association for the Study of the Pancreas (AISP) and the Italian Society of Alcohology (SIA)

Current estimates of the prevalence of chronic pancreatitis, one of the most common causes of exocrine pancreatic insufficiency, are in the range of 3-10 per 100,000 people in many parts of the world. Alcohol consumption is a very important risk factor for exocrine pancreatic insufficiency and is involved in nearly half of all cases. The main hypothesis regarding the role of chronic alcohol consumption in pancreatitis is that there must be additional environmental or genetic risk factors involved for ongoing damage to occur. Treatment of patients with alcohol-related exocrine pancreatic insufficiency is complex, as the patient has two concomitant pathologies, alcohol-use disorder (AUD) and exocrine pancreatic insufficiency/chronic pancreatitis. Alcohol abstinence is the starting point for treatment, although even this along with the most advanced therapies allow only a slowdown in progression rather than restoration of function. This position paper of the Italian Association for the Study of the Pancreas and the Italian Society of Alcohology provides an overview of the pathogenesis of alcohol-related pancreatitis and discuss diagnostic issues. Treatment options for both exocrine pancreatic insufficiency/chronic pancreatitis (with a focus on pancreatic enzyme replacement therapy) and AUD (acamprosate, disulfiram, oral naltrexone, long-acting injectable naltrexone, sodium oxybate, nalmefene, baclofen, and psychosocial interventions) are also reviewed.

Diagnosing Chronic Pancreatitis

Diagnosing CP can range from routine in those with severe disease and obvious calcifications on CT imaging to elusive in those patients with early changes in CP. The workup of suspected CP should follow a progressively noninvasive to more invasive STEP-wise approach in a patient with a suspicious clinical presentation and risk factors that raise their pretest probability of disease. After a thorough history and physical examination, basic laboratories should be obtained such as lipase, amylase, metabolic panel, and indirect PFTs (fecal elastase-1, serum trypsin). Computed tomography remains the best initial imaging modality to obtain as it has good sensitivity for severe CP and may obviate the need for other diagnostic tests. When equivocal, an MRCP should be obtained for a more detailed evaluation of the both the pancreatic parenchyma and ducts. If the diagnosis remains in doubt, EUS should be performed with or without pancreas function testing. ERCP remains a last-line diagnostic test and seldom should be used outside of therapeutic purposes. Future advances should target optimizing current diagnostic tools to more accurately diagnose early CP, as it is in this population where the benefits of delaying progression of CP may have the most profound effect. Likely the best way at establishing a diagnosis in these patients is via pancreatic function testing in the setting of indeterminate EUS results. Biomarker studies of pancreas fluid may supplement diagnosis.

Aryl Hydrocarbon Receptor Ligands in Cigarette Smoke Induce Production of Interleukin-22 to Promote Pancreatic Fibrosis in Models of Chronic Pancreatitis

BACKGROUND & AIMS

Cigarette smoke has been identified as an independent risk factor for chronic pancreatitis (CP). Little is known about the mechanisms by which smoking promotes development of CP. We assessed the effects of aryl hydrocarbon receptor (AhR) ligands found in cigarette smoke on immune cell activation in humans and pancreatic fibrosis in animal models of CP.

METHODS

We obtained serum samples from patients with CP treated at Stanford University hospital and healthy individuals (controls) and isolated CD4+ T cells. Levels of interleukin-22 (IL22) were measured by enzyme-linked immunosorbent assay and smoking histories were collected. T cells from healthy nonsmokers and smokers were stimulated and incubated with AhR agonists (2,3,7,8-tetrachlorodibenzo-p-dioxin or benzo[a]pyrene) or antagonists and analyzed by flow cytometry. Mice were given intraperitoneal injections of caerulein or saline, with or without lipopolysaccharide, to induce CP. Some mice were given intraperitoneal injections of AhR agonists at the start of caerulein injection, with or without an antibody against IL22 (anti-IL22) starting 2 weeks after the first caerulein injection, or recombinant mouse IL22 or vehicle (control) intraperitoneally 4 weeks after the first caerulein injection. Mice were exposed to normal air or cigarette smoke for 6 h/d for 7 weeks and expression of AhR gene targets was measured. Pancreata were collected from all mice and analyzed by histology and quantitative reverse transcription polymerase chain reaction. Pancreatic stellate cells and T cells were isolated and studied using immunoblot, immunofluorescence, flow cytometry, and enzyme-linked immunosorbent analyses.

RESULTS

Mice given AhR agonists developed more severe pancreatic fibrosis (based on decreased pancreas size, histology, and increased expression of fibrosis-associated genes) than mice not given agonists after caerulein injection. In mice given saline instead of caerulein, AhR ligands did not induce fibrosis. Pancreatic T cells from mice given AhR agonists and caerulein were activated and expressed IL22, but not IL17 or interferon gamma. Human T cells exposed to AhR agonists up-regulated expression of IL22. In mice given anti-IL22, pancreatic fibrosis did not progress, whereas mice given recombinant IL22 had a smaller pancreas and increased fibrosis. Pancreatic stellate cells isolated from mouse and human pancreata expressed the IL22 receptor IL22RA1. Incubation of the pancreatic stellate cells with IL22 induced their expression of the extracellular matrix genes fibronectin 1 and collagen type I α1 chain, but not α2 smooth muscle actin or transforming growth factor-β. Serum samples from smokers had significantly higher levels of IL22 than those from nonsmokers.

CONCLUSIONS

AhR ligands found in cigarette smoke increase the severity of pancreatic fibrosis in mouse models of pancreatitis via up-regulation of IL22. This pathway might be targeted for treatment of CP and serve as a biomarker of disease.

Length of Variable Numbers of Tandem Repeats in the Carboxyl Ester Lipase (CEL) Gene May Confer Susceptibility to Alcoholic Liver Cirrhosis but Not Alcoholic Chronic Pancreatitis

BACKGROUND

Carboxyl-ester lipase (CEL) contributes to fatty acid ethyl ester metabolism, which is implicated in alcoholic pancreatitis. The CEL gene harbours a variable number of tandem repeats (VNTR) region in exon 11. Variation in this VNTR has been linked to monogenic pancreatic disease, while conflicting results were reported for chronic pancreatitis (CP). Here, we aimed to investigate a potential association of CEL VNTR lengths with alcoholic CP.

METHODS

Overall, 395 alcoholic CP patients, 218 patients with alcoholic liver cirrhosis (ALC) serving as controls with a comparable amount of alcohol consumed, and 327 healthy controls from Germany and the United Kingdom (UK) were analysed by determination of fragment lengths by capillary electrophoresis. Allele frequencies and genotypes of different VNTR categories were compared between the groups.

RESULTS

Twelve repeats were overrepresented in UK ACP patients (P = 0.04) compared to controls, whereas twelve repeats were enriched in German ALC compared to alcoholic CP patients (P = 0.03). Frequencies of CEL VNTR lengths of 14 and 15 repeats differed between German ALC patients and healthy controls (P = 0.03 and 0.008, respectively). However, in the genotype and pooled analysis of VNTR lengths no statistical significant association was depicted. Additionally, the 16-16 genotype as well as 16 repeats were more frequent in UK ALC than in alcoholic CP patients (P = 0.034 and 0.02, respectively). In all other calculations, including pooled German and UK data, allele frequencies and genotype distributions did not differ significantly between patients and controls or between alcoholic CP and ALC.

CONCLUSIONS

We did not obtain evidence that CEL VNTR lengths are associated with alcoholic CP. However, our results suggest that CEL VNTR lengths might associate with ALC, a finding that needs to be clarified in larger cohorts.

Safety of Secretin Administration in Children

OBJECTIVE

The aim of this study was to compare the hemodynamic parameters from the anesthesia records of children who underwent upper gastrointestinal endoscopy (esophagogastroduodenoscopy [EGD]) with and without secretin pancreatic function tests (sPFTs).

METHODS

The hemodynamic parameters were retrieved from an electronic anesthesia database. The secretin group consisted of 186 children, and the age- and sex-matched control group included 136 patients who did not have sPFTs.

RESULTS

There was no difference in the demographic parameters (age and sex) between the 2 groups. The secretin group had a lower height and body mass index. The sPFT resulted in an average 3-minute extension of the endoscopic procedure. The heart rate increased during the EGD in both groups and was higher (averaged 7 beats per minute) in the secretin group than the EGD-only group. There were mild elevations on the systolic and diastolic blood pressures. None of these changes were clinically significant. There were no complications reported during the anesthesia and procedures in the 2 groups.

CONCLUSIONS

Secretin PFT is a safe procedure. It only slightly prolongs the total procedure and anesthesia time. There were no clinically significant changes in the vital parameters in the secretin group, and there were no adverse effects recorded.

Evaluation of Qualitative Magnetic Resonance Imaging Features for Diagnosis of Chronic Pancreatitis

OBJECTIVES

The purpose of this study was to determine qualitative pancreatic magnetic resonance imaging (MRI) features that must be present to predict abnormal pancreatic secretory function in patients evaluated for chronic pancreatitis (CP).

METHODS

The MRIs of study subjects were reviewed by 2 abdominal radiologists; qualitative parenchyma and ductal features were recorded. Endoscopic pancreatic function test (ePFT) results (reference standard) were classified as normal (peak pancreatic fluid bicarbonate [HCO3-] ≥75 meq/L) or abnormal (<75). Abnormal ePFT was further classified as mild/moderate (74-65) and marked deficiency (<65). Statistical analysis was performed to assess the association between MRI features and abnormal ePFT.

RESULTS

The study cohort was composed of 93 subjects, mean age 49 years (range, 18-78 years), 65% females. Univariate analysis identified 9 qualitative MRI features significantly (P < 0.05) associated with abnormal pancreatic secretory function. Number of MRI features increases as peak pancreatic fluid [HCO3-] decreases (Pearson r = -0.629; P = 0.001). Receiver operating characteristic curve analysis determined that a threshold of 6 or more associated MRI features 64% sensitive and 94% specific for marked bicarbonate deficiency.

CONCLUSIONS

Qualitative MRI parenchymal and ductal features are associated with CP. Presence of 6 or more features results in a higher specificity for the diagnosis of CP in advanced disease.

Approach to patients with suspected chronic pancreatitis: a comprehensive review

Chronic pancreatitis (CP) represents a significant health care burden in the United States. Diagnosing it early and accurately is important for the efficient management of these patients. However, the early diagnosis of CP, when structural and functional pancreatic changes are subtle, remains difficult. Complicating this is the large cohort of patients with nonspecific abdominal pain who are often suspected of having early CP and who utilize significant health care resources in attempts at diagnosis and management. We present a review of the current diagnostic tests available for making an early diagnosis of CP. We further report our approach to patients suspected of having CP based on the available literature.

Magnetic resonance imaging of pancreatitis: An update

Magnetic resonance (MR) imaging plays an important role in the diagnosis and staging of acute and chronic pancreatitis and may represent the best imaging technique in the setting of pancreatitis due to its unmatched soft tissue contrast resolution as well as non-ionizing nature and higher safety profile of intravascular contrast media, making it particularly valuable in radiosensitive populations such as pregnant patients, and patients with recurrent pancreatitis requiring multiple follow-up examinations. Additional advantages include the ability to detect early forms of chronic pancreatitis and to better differentiate adenocarcinoma from focal chronic pancreatitis. This review addresses new trends in clinical pancreatic MR imaging emphasizing its role in imaging all types of acute and chronic pancreatitis, pancreatitis complications and other important differential diagnoses that mimic pancreatitis.

High-resolution magic angle spinning (1)H magnetic resonance spectroscopy detects choline as a biomarker in a swine obstructive chronic pancreatitis model at an early stage

Chronic pancreatitis (CP) is a progressive inflammatory and fibrotic disease of the pancreas which encompasses a variety of clinical syndromes ranging from mild to life-threatening complications. Metabolomics has increasingly been applied to identify biomarkers for disease diagnosis with particular interest in diseases at an early stage. In this study, we tested a swine obstructive CP model by subtotal ligation of the main pancreatic duct, and the metabolic profiles of the Bama miniature swine pancreas were investigated using high-resolution magic angle spinning proton magnetic resonance spectroscopy (HR MAS (1)H MRS) combined with principal components analysis (PCA). Increases in lactate and choline for mild CP and decreases in glycerophosphocholine, phosphocholine, betaine and glycine were observed from normal pancreas to mild, moderate and severe CP. PCA results showed visual separations among the groups. The increase of choline at an early stage of CP and the decrease of glycerophosphocholine, phosphocholine, betaine and glycine reveal the pathogenesis of CP at a molecular level. The MRS results presented here demonstrate the potential of metabolic profiles in discriminating a normal pancreas from different stages of CP, which may be used to achieve CP early diagnosis and timely intervention to prevent irreversible destruction of the pancreas.

Mutant GNAS detected in duodenal collections of secretin-stimulated pancreatic juice indicates the presence or emergence of pancreatic cysts

OBJECTIVE

Pancreatic cysts are commonly detected in patients undergoing pancreatic imaging. Better approaches are needed to characterise these lesions. In this study we evaluated the utility of detecting mutant DNA in secretin-stimulated pancreatic juice.

DESIGN

Secretin-stimulated pancreatic juice was collected from the duodenum of 291 subjects enrolled in Cancer of the Pancreas Screening trials at five US academic medical centres. The study population included subjects with a familial predisposition to pancreatic cancer who underwent pancreatic screening, and disease controls with normal pancreata, chronic pancreatitis, sporadic intraductal papillary mucinous neoplasm (IPMN) or other neoplasms. Somatic GNAS mutations (reported prevalence ≈ 66% of IPMNs) were measured using digital high-resolution melt-curve analysis and pyrosequencing.

RESULTS

GNAS mutations were detected in secretin-stimulated pancreatic juice samples of 50 of 78 familial and sporadic cases of IPMN(s) (64.1%), 15 of 33 (45.5%) with only diminutive cysts (<5 mm), but none of 57 disease controls. GNAS mutations were also detected in five of 123 screened subjects without a pancreatic cyst. Among 97 subjects who had serial pancreatic evaluations, GNAS mutations detected in baseline juice samples predicted subsequent emergence or increasing size of pancreatic cysts.

CONCLUSION

Duodenal collections of secretin-stimulated pancreatic juice from patients with IPMNs have a similar prevalence of mutant GNAS to primary IPMNs, indicating that these samples are an excellent source of mutant DNA from the pancreas. The detection of GNAS mutations before an IPMN is visible suggests that analysis of pancreatic juice has the potential to help in the risk stratification and surveillance of patients undergoing pancreatic screening.

Difference gel electrophoresis identifies differentially expressed proteins in endoscopically collected pancreatic fluid

Alterations in the pancreatic fluid proteome of individuals with chronic pancreatitis (CP) may offer insights into the development and progression of the disease. The endoscopic pancreatic function test (ePFT) can safely collect large volumes of pancreatic fluid that are potentially amenable to proteomic analyses using difference gel electrophoresis (DIGE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Pancreatic fluid was collected endoscopically using the ePFT method following secretin stimulation from three individuals with severe CP and three chronic abdominal pain (CAP) controls. The fluid was processed to minimize protein degradation and the protein profiles of each cohort, as determined by DIGE and LC-MS/MS, were compared. This DIGE-LC-MS/MS analysis reveals proteins that are differentially expressed in CP compared with CAP controls. Proteins with higher abundance in pancreatic fluid from CP individuals include: actin, desmoplankin, α-1-antitrypsin, SNC73, and serotransferrin. Those of relatively lower abundance include carboxypeptidase B, lipase, α-1-antichymotrypsin, α-2-macroglobulin, actin-related protein (Arp2/3) subunit 4, glyceraldehyde-3-phosphate dehydrogenase, and protein disulfide isomerase. Endoscopic collection (ePFT) in tandem with DIGE-LC-MS/MS is a suitable approach for pancreatic fluid proteome analysis; however, further optimization of our protocol, as outlined herein, may improve proteome coverage in future analyses.

Cytokine profiling of pancreatic fluid using the ePFT collection method in tandem with a multiplexed microarray assay

Cytokines are secreted immunomodulating proteins involved in pancreatic stellate cell activation and propagation of fibrosis in chronic pancreatitis. We aim to show that cytokines can be identified from pancreatic fluid by (1) collecting pancreatic fluid with the ePFT method, (2) processing the fluid for cytokine-targeted microarray analysis, and (3) comparing cytokine profiles in pancreatic fluid of chronic pancreatitis (CP) patients and of chronic abdominal pain (CAP) controls. We endoscopically collected pancreatic fluid from patients with CP and those with CAP using the ePFT method. This fluid was subjected directly to a multiplexed cytokine protein microarray assay. Six patients (3 CP, 3 CAP) underwent a secretin-stimulated ePFT. The mean peak bicarbonate concentrations [meq/L] of the CP and CAP patients were 43 and 97, respectively. Statistically significant decreases in the cytokine concentrations of EGF, IP-10, eotaxin, IL-3, MIP-1a, IL-15, PDGF-AB/BB, and IL-1a were observed in the CP specimens (p<0.05). We have successfully identified differences in the abundance of cytokines in ePFT-collected pancreatic fluid with a multiplexed microarray assay comparing CP and CAP controls. Further targeted investigation of cytokines in ePFT-collected fluid will broaden our knowledge of pancreatic immune response and pathogenesis in chronic pancreatitis.

Optimized sample preparation of endoscopic collected pancreatic fluid for SDS-PAGE analysis

The standardization of methods for human body fluid protein isolation is a critical initial step for proteomic analyses aimed to discover clinically relevant biomarkers. Several caveats have hindered pancreatic fluid proteomics, including the heterogeneity of samples and protein degradation. We aim to optimize sample handling of pancreatic fluid that has been collected using a safe and effective endoscopic collection method (endoscopic pancreatic function test). Using SDS-PAGE protein profiling, we investigate (i) precipitation techniques to maximize protein extraction, (ii) auto-digestion of pancreatic fluid following prolonged exposure to a range of temperatures, (iii) effects of multiple freeze-thaw cycles on protein stability, and (iv) the utility of protease inhibitors. Our experiments revealed that TCA precipitation resulted in the most efficient extraction of protein from pancreatic fluid of the eight methods we investigated. In addition, our data reveal that although auto-digestion of proteins is prevalent at 23 and 37 degrees C, incubation on ice significantly slows such degradation. Similarly, when the sample is maintained on ice, proteolysis is minimal during multiple freeze-thaw cycles. We have also determined the addition of protease inhibitors to be assay-dependent. Our optimized sample preparation strategy can be applied to future proteomic analyses of pancreatic fluid.

Italian consensus guidelines for chronic pancreatitis

This paper gives practical guidelines for diagnosis and treatment of chronic pancreatitis. Statements have been elaborated by working teams of experts, by searching for and analysing the literature, and submitted to a consensus process by using a Delphi modified procedure. The statements report recommendations on clinical and nutritional approach, assessment of pancreatic function, treatment of exocrine pancreatic failure and of secondary diabetes, treatment of pain and prevention of painful relapses. Moreover, the role of endoscopy in approaching pancreatic pain, pancreatic stones, duct narrowing and dilation, and complications was considered. Recommendations for most appropriate use of various imaging techniques and of ultrasound endoscopy are reported. Finally, a group of recommendations are addressed to the surgical treatment, with definition of right indications, timing, most appropriate procedures and techniques in different clinical conditions and targets, and clinical and functional outcomes following surgery.

Combined endoscopic ultrasound and secretin endoscopic pancreatic function test in patients evaluated for chronic pancreatitis

BACKGROUND

Endoscopic ultrasound and endoscopic secretin pancreatic function test may be combined in a single endoscopic session (EUS/ePFT) to diagnose chronic pancreatitis (CP).

AIMS

Our primary aim was to assess the correlation and concordance of combined EUS and secretin ePFT bicarbonate results in suspected minimal change CP.

METHODS

Radial EUS included scoring for nine criteria (normal<4 criteria) with endoscopic collection of duodenal samples at 15, 30, and 45 min after secretin stimulation (normal peak bicarbonate>or=80 mmol/l).

RESULTS

Three hundred and two patients completed the EUS/ePFT (252 for suspected minimal change CP, 38 for established CP, 12 for painless steatorrhea). In patients evaluated for suspected minimal change CP, a moderate negative correlation was observed between endoscopic ultrasound score and peak bicarbonate (r=-0.38, P<0.001). The EUS and ePFT results were 76% concordant and 24% discordant. The ePFT was 85% sensitive and EUS was 100% sensitive for detecting patients with established calcific CP. The EUS/ePFT diagnosed CP in two of 12 of patients evaluated for painless steatorrhea or diarrhea with weight loss.

CONCLUSIONS

The combined EUS/ePFT is feasible and safe. There is only moderate correlation and concordance of endoscopic ultrasound and endoscopic pancreatic function test results in patients with suspected minimal change CP. The EUS and ePFT results produce complimentary functional and structural information for the evaluation of CP.

Identification of pancreas-specific proteins in endoscopically (endoscopic pancreatic function test) collected pancreatic fluid with liquid chromatography--tandem mass spectrometry

OBJECTIVES

We aimed to establish the endoscopic pancreatic function test (ePFT) as a method that can safely obtain pancreatic fluid for mass spectrometric analysis from patients during upper endoscopy and to reproducibly identify pancreas-specific proteins.

METHODS

We performed a sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry-based proteomic analysis (in-gel tryptic digestion followed by liquid chromatography-tandem mass spectrometry [GeLC-MS/MS]) on ePFT-collected pancreatic fluid from 3 individuals, without evidence of chronic pancreatitis, who were undergoing an upper endoscopy for dyspepsia and chronic abdominal pain.

RESULTS

Pancreatic fluid was safely collected from all subjects. The sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of ePFT-collected pancreatic fluid revealed no significant variation (F statistic, 1.33, P = 0.29) in protein concentration during the 1-hour collection period and a visually reproducible protein banding pattern among the 3 subjects. The GeLC-MS/MS analysis of ePFT-collected fluid identified pancreas-specific proteins previously described from endoscopic retrograde cholangiopancreatography and surgical collection methods. Gene ontology further revealed that most of the proteins identified have a molecular function of proteases.

CONCLUSIONS

The ePFT is capable of collecting large amounts of pancreatic fluid for proteomic analysis enabling the identification of pancreas-specific proteins. This endoscopic collection method coupled with GeLC-MS/MS is a powerful technique, which can be used in future investigations to elucidate pathways involved in the development and progression of pancreatic disease.

Pain management in chronic pancreatitis: A treatment algorithm

Abdominal pain is common and frequently debilitating in patients with chronic pancreatitis. Medical therapy includes abstinence from tobacco and alcohol and the use of analgesics and adjunctive agents. In many patients, a trial of non-enteric-coated pancreatic enzymes and/or antioxidants may be tried. Endoscopic or surgical therapy requires careful patient selection based on a detailed analysis of pancreatic ductal anatomy. Those with a non-dilated main pancreatic duct have limited endoscopic and surgical alternatives. The presence of a dilated main pancreatic duct makes endoscopic or surgical therapy possible, which may include ductal decompression or pancreatic resection, or both. Randomised trials suggest surgical therapy is more durable and effective than endoscopic therapy. Less commonly employed options include EUS-guided coeliac plexus block, thoracoscopic splanchnicectomy, or total pancreatectomy with auto islet cell transplantation. These are used rarely when all other options have failed and only in very carefully selected patients.

The revised Japanese clinical diagnostic criteria for chronic pancreatitis

In Japan, we are now using the clinical diagnostic criteria for chronic pancreatitis (CP) that were revised in 2001 to add the findings of magnetic resonance cholangiopancreatography to the criteria compiled by the Japan Pancreas Society (JPS) in 1995. Because the current criteria are set for diagnosing advanced CP, they are unlikely to improve patients' prognoses. In addition, they seem unsuitable for current clinical practice because exocrine pancreatic function tests, which have become obsolete in Japan, are included in the diagnostic factors. For these reasons, the Research Committee on Intractable Pancreatic Diseases supported by the Ministry of Health, Labour and Welfare of Japan, the JPS and the Japanese Society of Gastroenterology have revised the criteria. The revised criteria are unique in that they contain an introduction to the concept of early CP. It is a challenge aimed at improvement of the long-term prognosis of CP patients by early diagnosis and therapeutic intervention in this disease. We need to determine and clarify the clinico-pathological outcome of early CP by a prospective long-term follow-up of the patients in this category.

Chronic pancreatitis

PURPOSE OF REVIEW

We review important new clinical observations in chronic pancreatitis made in the last year.

RECENT FINDINGS

Cholecystokinin-stimulated endoscopic pancreatic function testing has low specificity for diagnosis of early chronic pancreatitis, likely because of correctable technical limitations or failure to exclude confounding diseases. Fecal elastase 1 is a poor test for diagnosing pancreatic malabsorption. A 2-week trial of corticosteroids may differentiate autoimmune pancreatitis (AIP) from pancreatic cancer in select patients. A genetic screen may help to predict relapse of AIP. Repeated, 6-month visits to counsel against alcohol use may reduce recurrent attacks of alcoholic pancreatitis. A five-component antioxidant cocktail may reduce the frequency of pain in chronic pancreatitis by 1.5 days per month.

SUMMARY

Researchers this last year have further characterized clinical aspects of chronic pancreatitis that may lead to improved detection of early chronic pancreatitis and AIP, risk stratification and application of risk-lowering strategies to prevent relapses in AIP or the development of recurrent (and possibly chronic) alcoholic pancreatitis and new evidence that antioxidants may have a modest effect on reducing the dominant symptom in chronic pancreatitis, abdominal pain.

Secretin-enhanced MRCP: proceed with cautious optimism

Magnetic resonance imaging (MRI) is a safe and universally available test that has much appeal to generalists and subspecialists evaluating patients with pancreatic disease. Testoni et al. report the clinical utility of magnetic resonance pancreaticocholangiography (MRCP) and secretin-enhanced MRCP in the evaluation of patients with asymptomatic abnormalities in pancreatic enzymes. The authors report that chronic pancreatitis changes will be seen in up to a third of patients with asymptomatic elevations in pancreas enzymes when compared with age-matched controls. The changes described on MRI and secretin-enhanced MRI are not in question, but the clinical significance of these changes is unknown. The authors rightly report that some of the changes seen may be age related, nonspecific, and of unknown clinical significance. Any new imaging and diagnostic test needs to be interpreted with caution until appropriate prospective clinical trials have been performed. It appears that secretin stimulation enhances the diagnostic accuracy of MRCP for the detection of minor changes in the pancreatic duct and parenchyma. Gastroenterologists are encouraged to proceed with cautious optimism when using MRI for the evaluation of early chronic pancreatitis.