Chronic pancreatitis: making the diagnosis

The Role of a Cholecystokinin Receptor Antagonist in the Management of Chronic Pancreatitis: A Phase 1 Trial

Chronic pancreatitis (CP) is a rare but debilitating condition with an 8-fold increased risk of developing pancreatic cancer. In addition to the symptoms that come from the loss of endocrine and exocrine function in CP, the management of chronic pain is problematic. We previously showed that the CCK-receptor antagonist called proglumide could decrease inflammation, acinar-ductal metaplasia, and fibrosis in murine models of CP. We hypothesized that proglumide would be safe and diminish pain caused by CP. A Phase 1 open-labeled safety study was performed in subjects with clinical and radiographic evidence of CP with moderate to severe pain. After a 4-week observation period, the subjects were treated with proglumide in 400 mg capsules three times daily (1200 mg per day) by mouth for 12 weeks, and then subjects returned for a safety visit 4 weeks after the discontinuation of the study medication. The results of three pain surveys (Numeric Rating Scale, COMPAT-SF, and NIH PROMIS) showed that the patients had significantly less pain after 12 weeks of proglumide compared to the pre-treatment observation phase. Of the eight subjects in this study, two experienced nausea and diarrhea with proglumide. These side effects resolved in one subject with doses reduced to 800 mg per day. No abnormalities were noted in the blood chemistries. A blood microRNA blood biomarker panel that corresponded to pancreatic inflammation and fibrosis showed significant improvement. We conclude that proglumide is safe and well tolerated in most subjects with CP at a dose of 1200 mg per day. Furthermore, proglumide therapy may have a beneficial effect by decreasing pain associated with CP.

Evaluation and management of exocrine pancreatic insufficiency: pearls and pitfalls

PURPOSE OF REVIEW

The diagnosis and management of exocrine pancreatic dysfunction (EPD) can be challenging. EPD classically results from conditions that cause loss of pancreatic acinar cell function and decreased digestive enzyme production. However, several conditions may contribute to signs or symptoms of EPD with otherwise normal pancreatic exocrine function. A thoughtful approach to considering these conditions, along with their specific therapies, can guide a tailored management approach.

RECENT FINDINGS

An EPD severity classification schema has been proposed, which emphasizes a shift towards a more restrictive prescription of pancreas enzyme replacement therapy (PERT) for patients with milder EPD. In contrast, PERT use has been associated with a measurable survival benefit among individuals with EPD and pancreatic cancer, so the prescription of PERT may be more liberal in this population. Recent publications in the cystic fibrosis population offer pearls guiding the titration and optimization of PERT.

SUMMARY

Among individuals with severe EPD, PERT is an effective therapy. Among individuals with milder EPD, although PERT is effective, there may be opportunities to provide additional and potentially more effective therapies.

Risk Prediction of Pancreatic Cancer in Patients With Abnormal Morphologic Findings Related to Chronic Pancreatitis: A Machine Learning Approach

BACKGROUND AND AIMS

A significant factor contributing to poor survival in pancreatic cancer is the often late stage at diagnosis. We sought to develop and validate a risk prediction model to facilitate the distinction between chronic pancreatitis-related vs potential early pancreatic ductal adenocarcinoma (PDAC)-associated changes on pancreatic imaging.

METHODS

In this retrospective cohort study, patients aged 18-84 years whose abdominal computed tomography/magnetic resonance imaging reports indicated duct dilatation, atrophy, calcification, cyst, or pseudocyst between January 2008 and November 2019 were identified. The outcome of interest is PDAC in 3 years. More than 100 potential predictors were extracted. Random survival forests approach was used to develop and validate risk models. Multivariable Cox proportional hazard model was applied to estimate the effect of the covariates on the risk of PDAC.

RESULTS

The cohort consisted of 46,041 (mean age 66.4 years). The 3-year incidence rate was 4.0 (95% confidence interval CI 3.6-4.4)/1000 person-years of follow-up. The final models containing age, weight change, duct dilatation, and either alkaline phosphatase or total bilirubin had good discrimination and calibration (c-indices 0.81). Patients with pancreas duct dilatation and at least another morphological feature in the absence of calcification had the highest risk (adjusted hazard ratio [aHR] = 14.15, 95% CI 8.7-22.6), followed by patients with calcification and duct dilatation (aHR = 7.28, 95% CI 4.09-12.96), and patients with duct dilation only (aHR = 6.22, 95% CI 3.86-10.03), compared with patients with calcifications alone as the reference group.

CONCLUSION

The study characterized the risk of pancreatic cancer among patients with 5 abnormal morphologic findings based on radiology reports and demonstrated the ability of prediction algorithms to provide improved risk stratification of pancreatic cancer in these patients.

Endoscopic Management of Complications in Chronic Pancreatitis

PURPOSE OF REVIEW

Management of complications in patients with chronic pancreatitis is often suboptimal. This review discusses detailed endoscopic approaches for managing complications in CP.

LITERATURE FINDINGS

CP is characterized by progressive and irreversible destruction of pancreatic parenchyma and ductal system resulting in fibrosis, scarring, and loss of glandular function. Abdominal pain remains is the most common symptom of the disease and the main aim of medical, endoscopic, and surgical therapy is to help relieve symptoms, prevent disease progression, and manage complications related to CP. In fact, advances in our understanding of CP have improved medical care and quality of life in these patients. With significant sequela, morbidity and a progressive nature, a thorough understanding of the pathophysiology, natural course, diagnostic approaches, and optimal management strategies for this disease is warranted. The existing modalities and new innovations in this field are safe, effective, and likely to have a positive impact on management of complication in CP whenever used in the right context.

Current advances in the management of chronic pancreatitis

Chronic pancreatitis is characterized by irreversible destruction of pancreatic parenchyma and its ductal system resulting from longstanding inflammation, leading to fibrosis and scarring due to genetic, environmental, and other risk factors. The diagnosis of chronic pancreatitis is made based on a combination of clinical features and characteristic findings on computed tomography or magnetic resonance imaging. Abdominal pain is the most common symptom of chronic pancreatitis. The main aim of treatment is to relieve symptoms, prevent disease progression, and manage complications related to chronic pancreatitis. Patients who do not respond to medical treatment or not a candidate for surgical treatment are usually managed with endoscopic therapies. Endoscopic therapies help with symptoms such as abdominal pain and jaundice by decompression of pancreatic and biliary ducts. This review summarizes the risk factors, pathophysiology, diagnostic evaluation, endoscopic treatment of chronic pancreatitis, and complications. We have also reviewed recent advances in endoscopic retrograde cholangiopancreatography and endoscopic ultrasound-guided therapies for pancreatic duct obstruction due to stones, strictures, pancreatic divisum, and biliary strictures.

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.

Cholecystokinin Receptor Antagonist Therapy Decreases Inflammation and Fibrosis in Chronic Pancreatitis

BACKGROUND AND AIMS

Chronic pancreatitis is associated with recurrent inflammation, pain, fibrosis, and loss of exocrine and endocrine pancreatic function and risk of cancer. We hypothesized that activation of the CCK receptor contributes to pancreatitis and blockade of this pathway would improve chronic pancreatitis.

METHODS

Two murine models were used to determine whether CCK receptor blockade with proglumide could prevent and reverse histologic and biochemical features of chronic pancreatitis: the 6-week repetitive chronic cerulein injection model and the modified 75% choline-deficient ethionine (CDE) diet. In the CDE-fed model, half the mice received water supplemented with proglumide, for 18 weeks. After chronic pancreatitis was established in the cerulein model, half the mice were treated with proglumide and half with water. Histology was scored in a blinded fashion for inflammation, fibrosis and acinar ductal metaplasia (ADM) and serum lipase levels were measured. RNA was extracted and examined for differentially expressed fibrosis genes.

RESULTS

Proglumide therapy decreased pancreatic weight in the CDE diet study and the cerulein-induced chronic pancreatitis model. Fibrosis, inflammation, and ADM scores were significantly reduced in both models. Lipase values improved with proglumide but not in controls in both models. Proglumide decreased pancreas mRNA expression of amylase, collagen-4, and TGFβR2 gene expression by 44, 38, and 25%, respectively, compared to control mice.

CONCLUSION

New strategies are needed to decreased inflammation and reduce fibrosis in chronic pancreatitis. CCK receptor antagonist therapy may improve chronic pancreatitis by reversing fibrosis and inflammation. The decrease in ADM may reduce the risk of the development of pancreatic cancer.

Chronic Pancreatitis: What the Clinician Wants to Know from MR Imaging

Diagnosis of chronic pancreatitis requires a complete medical history and clinical investigations, including imaging technologies and function tests. MR imaging/magnetic resonance cholangiopancreatography is the preferred diagnostic tool for detection of ductal and parenchymal changes in patients with chronic pancreatitis. Ductal changes may not be present in the initial phase of chronic pancreatitis. Therefore, early diagnosis remains challenging.

Association between chronic pancreatitis and urolithiasis: A population-based cohort study

Purpose

Chronic pancreatitis (CP) can cause fat or bile acid malabsorption due to exocrine insufficiency. Fat or bile acid malabsorption has been reported to increase the risk of urolithiasis through increased intestinal oxalate absorption. However, no studies have reported an association between CP and urolithiasis.

Methods

We identified 15,848 patients (age: ≥20 years) diagnosed as having CP between 2000 and 2010 from the National Health Insurance Research Database as the study cohort. Beneficiaries without a history of CP were randomly selected and propensity-matched with the study cohort in a 1:4 ratio according to age; sex; comorbidities of hyperlipidemia, diabetes, obesity, hypertension, chronic obstructive pulmonary disease, alcohol-related illness, stroke, and coronary artery disease; and the index date. The prevalence of inflammatory bowel disease (0.44%), hyperparathyroidism (0.10%), or end stage renal disease (1.55%) in CP patients was low, but these comorbidities were also considered in the analysis. All patients were followed until the end of 2011 or withdrawal from the National Health Insurance program to determine the incidence of urolithiasis.

Results

The cumulative incidence of urolithiasis was higher in the CP cohort than that in the non-CP cohort (log-rank test, P < 0.001) with a 1.89-fold risk of urolithiasis (95% confidence interval [CI] = 1.74–2.06). The prevalence of CP was higher in men (81.9%) and in patients younger than 49 years (63.5%; mean age: 48.5 ± 15.3 years). CP was associated with the development of urolithiasis in each age group (≤49 years: aHR = 2.00, 95% CI = 1.81–2.22; 50–64 years: aHR = 1.71, 95% CI = 1.40–2.09; ≥65 years: aHR = 1.54, 95% CI = 1.20–1.98) and each sex (women: aHR = 2.10, 95% CI = 1.67–2.66; men; aHR = 1.86, 95% CI = 1.70–2.04). Among the patients without comorbidities, the rate of urolithiasis increased from 2.93/1,000 person-years in non-CP patients to 8.28/1,000 person-years in CP patients. Among the patients with comorbidities, the rate of urolithiasis increased from 6.12/1,000 person-years in non-CP patients to 10.9/1,000 person-years in CP patients. The contribution of CP to the relative risk of urolithiasis was greater in patients without comorbidities (without comorbidities: aHR = 2.81, 95% CI = 2.30–3.44) than in those with comorbidities (aHR = 1.76, 95% CI = 1.61–1.94).

Conclusion

CP is associated with urolithiasis in this population-based cohort study. The contribution of CP to the relative risk of urolithiasis was even greater in patients with a lower risk of urolithiasis, such as those without other comorbidities. Our findings warrant a survey and education on urolithiasis for patients with CP.

The Impact of Risk Factors of Chronic Pancreatitis on Secretin Pancreatic Function Testing: Results of a 20-Year Study

OBJECTIVES

The aim of this study was to determine the effect of established risk factors on the outcome of secretin pancreatic function testing (sPFT) in patients undergoing work-up for suspected chronic pancreatitis.

METHODS

We completed a retrospective review of patients who underwent sPFT for suspected chronic pancreatitis over 20 years. We compared peak bicarbonate concentrations between groups and completed univariate and multivariate analyses to determine associations between risk factors and positive sPFT results (peak bicarbonate <80 mEq/L).

RESULTS

Forty-three of 162 patients had positive sPFT results. There were significant differences in peak bicarbonate concentrations in patients with and without recurrent acute pancreatitis (RAP) and with local complications from acute pancreatitis (AP) (P ≤ 0.05). The bicarbonate concentration in patients with and without other risk factors such as tobacco use, alcohol use, and family history of pancreatitis was not significantly different. Female sex, a history of AP, and a history of RAP were associated with positive sPFT results on univariate analysis (P ≤ 0.05). On multivariate analysis, sex and RAP remained significant.

CONCLUSIONS

Our study demonstrates that female sex, history of AP and RAP, and AP with local complications are associated with positive sPFT results or lower peak bicarbonate concentration. However, other risk factors do not impact the results of sPFT.

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.

Comparison of Combined Endoscopic Ultrasonography and Endoscopic Secretin Testing With the Traditional Secretin Pancreatic Function Test in Patients With Suspected Chronic Pancreatitis: A Prospective Crossover Study

OBJECTIVE

We aimed to determine the feasibility and accuracy of a combined endoscopic ultrasonography (EUS) with a shortened pancreatic function testing (sEUS) for structural and functional assessment using a single instrument in patients with suspected chronic pancreatitis (CP).

METHODS

We completed a prospective crossover study, enrolling patients with suspected CP. Patients who underwent both traditional 1-hour secretin pancreatic function test (sPFT) and sEUS were included in the analysis. We compared study results for test concordance and for correlation of peak bicarbonate concentrations.

RESULTS

Eleven (64.7%) of 17 patients had concordant sPFT and sEUS findings when the cutoff for peak bicarbonate was 80 mEq/L. Six patients had discordant findings with a negative sPFT and positive sEUS. This poor concordance suggests that sEUS is an unreliable functional test. Lowering the sEUS cutoff to 70 mEq/L resulted in improved concordance (64.7% vs 70.6%). Finally, there was no significant correlation between peak bicarbonate concentrations (r = 0.47; 95% confidence interval, -0.02 to 0.79) in these 2 functional tests.

CONCLUSIONS

We demonstrate poor concordance between sPFT and sEUS suggesting that a combined shortened functional and structural test using a single instrument may not be a feasible test for diagnosis of suspected CP when a cutoff of 80 mEq/L is used.

Diagnosis of Chronic Pancreatitis Incorporating Endosonographic Features, Demographics, and Behavioral Risk

OBJECTIVES

Diagnosing chronic pancreatitis remains challenging. Endoscopic ultrasound (EUS) is utilized to evaluate pancreatic disease. Abnormal pancreas function test is considered the "nonhistologic" criterion standard for chronic pancreatitis. We derived a prediction model for abnormal endoscopic pancreatic function test (ePFT) by enriching EUS findings with patient demographic and pancreatitis behavioral risk characteristics.

METHODS

Demographics, behavioral risk characteristics, EUS findings, and peak bicarbonate results were collected from patients evaluated for pancreatic disease. Abnormal ePFT was defined as peak bicarbonate of less than 75 mEq/L. We fit a logistic regression model and converted it to a risk score system. The risk score was validated using 1000 bootstrap simulations.

RESULTS

A total of 176 patients were included; 61% were female with median age of 48 years (interquartile range, 38-57 years). Abnormal ePFT rate was 39.2% (69/176). Four variables formulated the risk score: alcohol or smoking status, number of parenchymal abnormalities, number of ductal abnormalities, and calcifications. Abnormal ePFT occurred in 10.7% with scores 4 or less versus 92.0% scoring 20 or greater. The model C-statistic was 0.78 (95% confidence interval, 0.71-0.85).

CONCLUSIONS

Number of EUS pancreatic duct and parenchymal abnormalities, presence of calcification, and smoking/alcohol status were predictive of abnormal ePFT. This simple model has good discrimination for ePFT results.

Can We Detect Chronic Pancreatitis With Low Serum Pancreatic Enzyme Levels?

OBJECTIVES

The aims of this study were to evaluate whether serum pancreatic enzyme levels could be used to aid screening for chronic pancreatitis (CP).

METHODS

170 healthy volunteers were screened and prospectively enrolled in the control group. 150 patients who were diagnosed with calcific CP were enrolled in the patient group by retrospective review. Serum amylase and lipase levels were compared between the 2 groups.

RESULTS

The mean values ± SD of the control group were compared with those of the patient group for serum amylase level (48.1 ± 13.2 vs 34.8 ± 17.2 U/L, P < 0.001) and serum lipase level (26.4 ± 11.3 vs 16.3 ± 11.2 U/L, P < 0.001). On the receiver operating characteristic curve analysis for amylase level, area under the curve was 0.740 (95% confidence interval), and sensitivity and specificity were 38.7% and 94.1%, respectively, with a cutoff value of 27.5 U/L. On the receiver operating characteristic curve analysis for lipase level, area under the curve was 0.748 (95% confidence interval), and sensitivity and specificity were 33.3% and 95.9%, respectively, with a cutoff value of 10.5 U/L.

CONCLUSIONS

Our results suggest that low serum pancreatic enzyme levels can be used to aid in detection of CP.

Computed tomography for diagnosis of early chronic pancreatitis in a rat model

AIM: To assess the value of computed tomography (CT) in the diagnosis of early chronic pancreatitis (CP) in a rat model.

METHODS: A rat model of chronic pancreatitis was established by injection of dibutyltin dichloride (DBTC), and control rats were treated with equal volume of physiological saline. The animals were sacrificed 7 d, 14 d, and 28 d after injection. Abdominal CT scans were performed in all rats, and serum amylase (AMY), lipase (LIPA), aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBIL) and fasting blood glucose were detected. Histopathology of rat pancreas was assessed by HE staining.

RESULTS: Serum ALT and TBIL increased in both early and late stages of CP. CT scans revealed that there was a significant difference in rat pancreatic histopathology by HE staining among 7 d, 14 d, and 28 d after injection of DBTC.

CONCLUSION: CT imaging characteristics of early CP are very important for the early diagnosis and treatment of this disease.

Chronic pancreatitis: A diagnostic dilemma

Typical clinical symptoms of chronic pancreatitis are vague and non-specific and therefore diagnostic tests are required, none of which provide absolute diagnostic certainly, especially in the early stages of disease. Recently-published guidelines bring much needed structure to the diagnostic work-up of patients with suspected chronic pancreatitis. In addition, novel diagnostic modalities bring promise for the future. The assessment and diagnosis of pancreatic exocrine insufficiency remains challenging and this review contests the accepted perspective that steatorrhea only occurs with > 90% destruction of the gland.

Diagnosis of Exocrine Pancreatic Insufficiency

OPINION STATEMENT

The accurate diagnosis of exocrine pancreatic insufficiency (EPI) helps identify those in need of pancreatic enzyme replacement therapy. Conversely, ruling out EPI identifies those in which additional evaluation should be pursued to explain their symptoms. There are many available tests that can be used to diagnose EPI; however, the tests must be tailored to each clinical scenario. Tests that are convenient but less accurate (e.g., fecal elastase-1, qualitative fecal fat determination) are best suited for patients with a high pretest probability of EPI. In contrast, tests that are highly accurate but more cumbersome (e.g., endoscopic pancreatic function testing, 72-h fecal fat collection) are favored in patients suspected to have mild EPI or an early stage of chronic pancreatitis. Additional research is needed to identify a more convenient means of accurately diagnosing at all stages of EPI.

Pancreatitis-imaging approach

Pancreatitis is defined as the inflammation of the pancreas and considered the most common pancreatic disease in children and adults. Imaging plays a significant role in the diagnosis, severity assessment, recognition of complications and guiding therapeutic interventions. In the setting of pancreatitis, wider availability and good image quality make multi-detector contrast-enhanced computed tomography (MD-CECT) the most used imaging technique. However, magnetic resonance imaging (MRI) offers diagnostic capabilities similar to those of CT, with additional intrinsic advantages including lack of ionizing radiation and exquisite soft tissue characterization. This article reviews the proposed definitions of revised Atlanta classification for acute pancreatitis, illustrates a wide range of morphologic pancreatic parenchymal and associated peripancreatic changes for different types of acute pancreatitis. It also describes the spectrum of early and late chronic pancreatitis imaging findings and illustrates some of the less common types of chronic pancreatitis, with special emphasis on the role of CT and MRI.

Management of chronic pancreatitis

Advances in our understanding of chronic pancreatitis have improved our care of patients with this disease. Although our therapies are imperfect and many patients remain symptomatic, appropriate medical care improves the quality of life in these patients. Proper management requires an accurate diagnosis, recognition of the modifiable causes of disease, assessment of symptoms and complications, treatment of these symptoms and complications utilizing a multidisciplinary team, and ongoing monitoring for the effect of therapy and the occurrence of complications.