Circulating immune signatures in chronic pancreatitis with and without preceding acute pancreatitis: A pilot study

OBJECTIVE

To investigate profiles of circulating immune signatures in healthy controls and chronic pancreatitis patients (CP) with and without a preceding history of acute pancreatitis (AP).

METHODS

We performed a phase 1, cross-sectional analysis of prospectively collected serum samples from the PROspective Evaluation of Chronic Pancreatitis for EpidEmiologic and Translation StuDies (PROCEED) study. All samples were collected during a clinically quiescent phase. CP subjects were categorized into two subgroups based on preceding episode(s) of AP. Healthy controls were included for comparison. Blinded samples were analyzed using an 80-plex Luminex assay of cytokines, chemokines, and adhesion molecules. Group and pairwise comparisons of analytes were performed between the subgroups.

RESULTS

In total, 133 patients with CP (111 with AP and 22 without AP) and 50 healthy controls were included. Among the 80 analytes studied, CP patients with a history of AP had significantly higher serum levels of pro-inflammatory cytokines (interleukin (IL)-6, IL-8, IL-1 receptor antagonist, IL-15) and chemokines (Cutaneous T-Cell Attracting Chemokine (CTACK), Monokine induced Gamma Interferon (MIG), Macrophage-derived Chemokine (MDC), Monocyte Chemoattractant Protein-1 (MCP-1)) compared to CP without preceding AP and controls. In contrast, CP patients without AP had immune profiles characterized by low systemic inflammation and downregulation of anti-inflammatory mediators, including IL-10.

CONCLUSION

CP patients with a preceding history of AP have signs of systemic inflammatory activity even during a clinically quiescent phase. In contrast, CP patients without a history of AP have low systemic inflammatory activity. These findings suggest the presence of two immunologically diverse subtypes of CP.

Utilization of Pancreatic Endotherapy in Patients with Chronic Pancreatitis: Results From a Multicenter Cohort Study in the United States

BACKGROUND AND AIMS

Although commonly used for treating complications of chronic pancreatitis (CP), data on the frequency and factors associated with the use of pancreatic endotherapy (PET) are limited. Our aim was to define the utilization and factors predictive for receiving PET in a well-characterized CP cohort.

METHODS

This is a cross-sectional analysis of data from PROCEED, a multicenter US cohort study of CP. PET modalities primarily consisted of ERCP. A treatment course was defined as the number of sessions performed for a specific indication. A repeat course was defined as PET >1 year after completion of the last course. Multivariable logistic regression identified predictive factors for receiving PET, and proportional rates model assessed risk factors for repeat PET.

RESULTS

Of a total of 681 subjects, 238 (34.9%) received PET. Factors associated with receiving PET included female sex (OR: 1.26, 95% CI: 1.03-1.53), lower education (OR: 1.30, 95% CI: 1.04-1.62), income ≤ $50,000 per year (OR: 1.35, 95% CI: 1.07-1.71) and prior acute pancreatitis (AP) (OR: 1.74, 95% CI: 1.31, 2.32). 103/238 subjects (43.3%) underwent repeat PET at a median duration of 2 years with 23.1% receiving 2 courses, 9.7% receiving 3 courses, and 10.4% receiving 4+ courses.

CONCLUSIONS

Nearly half of patients with CP who undergo PET received one or more repeat courses within 2-3 years. In addition to a prior history of AP, demographic and socioeconomic factors were associated with receiving PET.

Systemic Neutrophil Gelatinase-Associated Lipocalin Alterations in Chronic Pancreatitis: A Multicenter, Cross-Sectional Study

INTRODUCTION

Chronic pancreatitis (CP) is a progressive fibroinflammatory disorder lacking therapies and biomarkers. Neutrophil gelatinase-associated lipocalin (NGAL) is a proinflammatory cytokine elevated during inflammation that binds fatty acids (FAs) such as linoleic acid. We hypothesized that systemic NGAL could serve as a biomarker for CP and, with FAs, provide insights into inflammatory and metabolic alterations.

METHODS

NGAL was measured by immunoassay, and FA composition was measured by gas chromatography in plasma (n = 171) from a multicenter study, including controls (n = 50), acute and recurrent acute pancreatitis (AP/RAP) (n = 71), and CP (n = 50). Peripheral blood mononuclear cells (PBMCs) from controls (n = 16), AP/RAP (n = 17), and CP (n = 15) were measured by cytometry by time-of-flight.

RESULTS

Plasma NGAL was elevated in subjects with CP compared with controls (area under the curve [AUC] = 0.777) or AP/RAP (AUC = 0.754) in univariate and multivariate analyses with sex, age, body mass index, and smoking (control AUC = 0.874; AP/RAP AUC = 0.819). NGAL was elevated in CP and diabetes compared with CP without diabetes ( P < 0.001). NGAL + PBMC populations distinguished CP from controls (AUC = 0.950) or AP/RAP (AUC = 0.941). Linoleic acid was lower, whereas dihomo-γ-linolenic and adrenic acids were elevated in CP ( P < 0.05). Linoleic acid was elevated in CP with diabetes compared with CP subjects without diabetes ( P = 0.0471).

DISCUSSION

Elevated plasma NGAL and differences in NGAL + PBMCs indicate an immune response shift that may serve as biomarkers of CP. The potential interaction of FAs and NGAL levels provide insights into the metabolic pathophysiology and improve diagnostic classification of CP.

Circulating immune signatures across clinical stages of chronic pancreatitis: a pilot study

OBJECTIVE

This pilot study seeks to identify serum immune signatures across clinical stages of patients with chronic pancreatitis (CP).

METHODS

We performed a cross-sectional analysis of prospectively collected serum samples from the PROspective Evaluation of Chronic Pancreatitis for EpidEmiologic and Translation StuDies-study. CP subjects were categorised into three clinical stages based on the presence/absence of metabolic complications: (1) CP with no diabetes and exocrine pancreatic dysfunction (EPD), (2) CP with either diabetes or EPD, and (3) CP with diabetes and EPD. Blinded samples were analysed using an 80-plex Luminex assay of cytokines/chemokines/adhesion molecules. Group and pairwise comparisons were performed to characterise immune signatures across CP subgroups.

RESULTS

A total of 135 CP subjects (evenly distributed between clinical stages) and 50 controls were studied. Interleukin-6 (IL-6), interleukin-8 (IL-8), and soluble intercellular adhesion molecule 1 (sICAM-1) were significantly elevated in CP subjects compared to controls. The levels of IL-6 and IL-8 increased with advancing disease stages, with the highest levels observed in CP with diabetes and EPD (clinical stage 3). Furthermore, hepatocyte growth factor and macrophage-derived chemokine were significantly increased in clinical stage 3 compared to controls.

CONCLUSION

Our study reveals a progressive elevation in pro-inflammatory cytokines and chemokines with advancing clinical stages of CP. These findings indicate potential targets for the development of disease-modifying interventions.

Spatial transcriptomic analysis drives PET imaging of tight junction protein expression in pancreatic cancer theranostics

We apply spatial transcriptomics and proteomics to select pancreatic cancer surface receptor targets for molecular imaging and theranostics using an approach that can be applied to many cancers. Selected cancer surfaceome epithelial markers were spatially correlated and provided specific cancer localization, whereas the spatial correlation between cancer markers and immune- cell or fibroblast markers was low. While molecular imaging of cancer-associated fibroblasts and integrins has been proposed for pancreatic cancer, our data point to the tight junction protein claudin-4 as a theranostic target. Claudin-4 expression increased ∼16 fold in cancer as compared with normal pancreas, and the tight junction localization conferred low background for imaging in normal tissue. We developed a peptide-based molecular imaging agent targeted to claudin-4 with accumulation to ∼25% injected activity per cc (IA/cc) in metastases and ∼18% IA/cc in tumors. Our work motivates a new approach for data-driven selection of molecular targets.

Serum Biomarkers of Nociceptive and Neuropathic Pain in Chronic Pancreatitis

Debilitating abdominal pain is a common symptom affecting most patients with chronic pancreatitis (CP). There are multiple underlying mechanisms that contribute to CP-related pain, which makes successful treatment difficult. The identification of biomarkers for subtypes of pain could provide viable targets for nonopioid interventions and the development of mechanistic approaches to pain management in CP. Nineteen inflammation- and nociception-associated proteins were measured in serum collected from 358 subjects with definite CP enrolled in PROspective Evaluation of Chronic Pancreatitis for EpidEmiologic and Translational StuDies, a prospective observational study of pancreatitis in US adult subjects. First, serum levels of putative biomarkers were compared between CP subjects with and without pain. Only platelet-derived growth factor B (PDGF-B) stood out, with levels significantly higher in the CP pain group as compared to subjects with no pain. Subjects with pain were then stratified into 4 pain subtypes (Neuropathic, Nociceptive, Mixed, and Unclassified). A comparison of putative biomarker concentration among 5 groups (no pain and 4 pain subtypes) identified unique proteins that were correlated with pain subtypes. Serum transforming growth factor beta 1 (TGFβ1) level was significantly higher in the Nociceptive pain group compared to the No pain group, suggesting that TGFβ1 may be a biomarker for nociceptive pain. The Neuropathic pain only group was too small to detect statistical differences. However, glycoprotein 130 (GP130), a coreceptor for interleukin 6, was significantly higher in the Mixed pain group compared to the groups lacking a neuropathic pain component. These data suggest that GP130 may be a biomarker for neuropathic pain in CP. PERSPECTIVE: Serum TGFβ1 and GP130 may be biomarkers for nociceptive and neuropathic CP pain, respectively. Preclinical data suggest inhibiting TGFβ1 or GP130 reduces CP pain in rodent models, indicating that additional translational and clinical studies may be warranted to develop a precision medicine approach to the management of pain in CP.

Diagnosis of chronic pancreatitis using semi-quantitative MRI features of the pancreatic parenchyma: results from the multi-institutional MINIMAP study

PURPOSE

To determine the diagnostic performance of parenchymal MRI features differentiating CP from controls.

METHODS

This prospective study performed abdominal MRI scans at seven institutions, using 1.5 T Siemens and GE scanners, in 50 control and 51 definite CP participants, from February 2019 to May 2021. MRI parameters included the T1-weighted signal intensity ratio of the pancreas (T1 score), arterial-to-venous enhancement ratio (AVR) during venous and delayed phases, pancreas volume, and diameter. We evaluated the diagnostic performance of these parameters individually and two semi-quantitative MRI scores derived using logistic regression: SQ-MRI Model A (T1 score, AVR venous, and tail diameter) and Model B (T1 score, AVR venous, and volume).

RESULTS

When compared to controls, CP participants showed a significantly lower mean T1 score (1.11 vs. 1.29), AVR venous (0.86 vs. 1.45), AVR delayed (1.07 vs. 1.57), volume (54.97 vs. 80.00 ml), and diameter of the head (2.05 vs. 2.39 cm), body (2.25 vs. 2.58 cm), and tail (1.98 vs. 2.51 cm) (p < 0.05 for all). AUCs for these individual MR parameters ranged from 0.66 to 0.79, while AUCs for the SQ-MRI scores were 0.82 and 0.81 for Model A (T1 score, AVR venous, and tail diameter) and Model B (T1 score, AVR venous, and volume), respectively. After propensity-matching adjustments for covariates, AUCs for Models A and B of the SQ-MRI scores increased to 0.92 and 0.93, respectively.

CONCLUSION

Semi-quantitative parameters of the pancreatic parenchyma, including T1 score, enhancement ratio, pancreas volume, diameter and multi-parametric models combining these parameters are helpful in diagnosis of CP. Longitudinal analyses including more extensive population are warranted to develop new diagnostic criteria for CP.

A Combined DNA/RNA-based Next-Generation Sequencing Platform to Improve the Classification of Pancreatic Cysts and Early Detection of Pancreatic Cancer Arising From Pancreatic Cysts

OBJECTIVE

We report the development and validation of a combined DNA/RNA next-generation sequencing (NGS) platform to improve the evaluation of pancreatic cysts.

BACKGROUND AND AIMS

Despite a multidisciplinary approach, pancreatic cyst classification, such as a cystic precursor neoplasm, and the detection of high-grade dysplasia and early adenocarcinoma (advanced neoplasia) can be challenging. NGS of preoperative pancreatic cyst fluid improves the clinical evaluation of pancreatic cysts, but the recent identification of novel genomic alterations necessitates the creation of a comprehensive panel and the development of a genomic classifier to integrate the complex molecular results.

METHODS

An updated and unique 74-gene DNA/RNA-targeted NGS panel (PancreaSeq Genomic Classifier) was created to evaluate 5 classes of genomic alterations to include gene mutations (e.g., KRAS, GNAS, etc.), gene fusions and gene expression. Further, CEA mRNA ( CEACAM5 ) was integrated into the assay using RT-qPCR. Separate multi-institutional cohorts for training (n=108) and validation (n=77) were tested, and diagnostic performance was compared to clinical, imaging, cytopathologic, and guideline data.

RESULTS

Upon creation of a genomic classifier system, PancreaSeq GC yielded a 95% sensitivity and 100% specificity for a cystic precursor neoplasm, and the sensitivity and specificity for advanced neoplasia were 82% and 100%, respectively. Associated symptoms, cyst size, duct dilatation, a mural nodule, increasing cyst size, and malignant cytopathology had lower sensitivities (41-59%) and lower specificities (56-96%) for advanced neoplasia. This test also increased the sensitivity of current pancreatic cyst guidelines (IAP/Fukuoka and AGA) by >10% and maintained their inherent specificity.

CONCLUSIONS

PancreaSeq GC was not only accurate in predicting pancreatic cyst type and advanced neoplasia but also improved the sensitivity of current pancreatic cyst guidelines.

Pancreatic Cyst Fluid Analysis

Pancreatic cyst fluid analysis can help diagnose pancreatic cyst type and the risk of high-grade dysplasia and cancer. Recent evidence from molecular analysis of cyst fluid has revolutionized the field with multiple markers showing promise in accurate diagnosis and prognostication of pancreatic cysts. The availability of multi-analyte panels has great potential for more accurate prediction of cancer.

Association of Chronic Pancreatitis Pain Features With Physical, Mental, and Social Health

BACKGROUND AND AIMS

Pain is a cardinal symptom of chronic pancreatitis (CP). Using Patient-Reported Outcomes Measurement Information System (PROMIS) measures, we characterized physical and mental health and symptom profiles of a well-defined cohort of individuals with CP and compared them with control subjects. Among patients with CP, we also examined associations between pain (intensity, temporal nature) and PROMIS symptom profiles and the prevalence of clinically significant psychological comorbidities.

METHODS

We analyzed baseline data in 488 CP patients and 254 control subjects enrolled in PROCEED (Prospective Evaluation of Chronic Pancreatitis for Epidemiologic and Translational Studies), an ongoing longitudinal cohort study. Participants completed the PROMIS-Global Health, which captures global physical and mental health, and the PROMIS-29 profile, which captures 7 symptom domains. Self-reported pain was categorized by severity (none, mild-moderate, severe) and temporal nature (none, intermittent, constant). Demographic and clinical data were obtained from the PROCEED database.

RESULTS

Pain was significantly associated with impairments in physical and mental health. Compared with participants with no pain, CP participants with severe pain (but not mild-moderate pain) had more decrements in each PROMIS domain in multivariable models (effect sizes, 2.54-7.03) and had a higher prevalence of clinically significant depression, anxiety, sleep disturbance, and physical disability (odds ratios, 2.11-4.74). Similar results were noted for constant pain (but not intermittent pain) for PROMIS domains (effect sizes, 4.08-10.37) and clinically significant depression, anxiety, sleep disturbance and physical disability (odds ratios, 2.80-5.38).

CONCLUSIONS

Severe and constant pain are major drivers for poor psychological and physical health in CP. Systematic evaluation and management of psychiatric comorbidities and sleep disturbance should be incorporated into routine management of patients with CP. (ClinicalTrials.gov, Number: NCT03099850).

A Reduced Pancreatic Polypeptide Response is Associated With New-onset Pancreatogenic Diabetes Versus Type 2 Diabetes

PURPOSE

Pancreatogenic diabetes refers to diabetes mellitus (DM) that develops in the setting of a disease of the exocrine pancreas, including pancreatic ductal adenocarcinoma (PDAC) and chronic pancreatitis (CP). We sought to evaluate whether a blunted nutrient response of pancreatic polypeptide (PP) can differentiate these DM subtypes from type 2 DM (T2DM).

METHODS

Subjects with new-onset DM (<3 years' duration) in the setting of PDAC (PDAC-DM, n = 28), CP (CP-DM, n = 38), or T2DM (n = 99) completed a standardized mixed meal tolerance test, then serum PP concentrations were subsequently measured at a central laboratory. Two-way comparisons of PP concentrations between groups were performed using Wilcoxon rank-sum test and analysis of covariance while adjusting for age, sex, and body mass index.

RESULTS

The fasting PP concentration was lower in both the PDAC-DM and CP-DM groups than in the T2DM group (P = 0.03 and <0.01, respectively). The fold change in PP at 15 minutes following meal stimulation was significantly lower in the PDAC-DM (median, 1.869) and CP-DM (1.813) groups compared with T2DM (3.283; P < 0.01 for both comparisons). The area under the curve of PP concentration was significantly lower in both the PDAC-DM and CP-DM groups than in T2DM regardless of the interval used for calculation and remained significant after adjustments.

CONCLUSIONS

Fasting PP concentrations and the response to meal stimulation are reduced in new-onset DM associated with PDAC or CP compared with T2DM. These findings support further investigations into the use of PP concentrations to characterize pancreatogenic DM and to understand the pathophysiological role in exocrine pancreatic diseases (NCT03460769).

Distinct serum immune profiles define the spectrum of acute and chronic pancreatitis from the multi-center PROCEED study

BACKGROUND AND AIMS

Pancreatitis is a disease continuum, starting with acute pancreatitis (AP) and, in some cases, progressing to recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP). Currently, there are no approved therapies or early diagnostic or prognostic biomarkers for pancreatitis. The current study aimed to examine whether patient serum immune profiling could identify non-invasive biomarkers and provide mechanistic insight into the disease continuum of pancreatitis.

METHODS

Using Olink immunoassay, we assessed the protein levels of 92 immune markers in serum samples from participants enrolled in the PROCEED study of the CPDPC consortium. Samples (n=231) were obtained from subjects without the pancreatic disease (n=56) and those with chronic abdominal pain (CAP) (n=24), AP (n=38), RAP (n=56), and CP (n=57).

RESULTS

Thirty-three immune markers differentiated the combined pancreatitis groups from controls. Immune markers related to IL-17 signaling distinguished CP from AP and RAP. Similarly, the serum level of IL-17A and CCL20 differentiated CP from CAP, suggesting the involvement of Th17 cells in CP pathogenesis. The receiver operator characteristic (ROC) curve with two immune markers (IL-17A and ST1A1) could differentiate CP from CAP (optimistic AUC=0.78). Macrophage classical activation pathway elevated along the continuum of pancreatitis, suggesting an accumulation of proinflammatory signals over disease progression. Several immune markers were associated with smoking, alcohol, and diabetes status.

CONCLUSION

Immune profiling of serum samples from a large pancreatitis cohort led to identifying distinct immune markers that could serve as potential biomarkers to differentiate the varying pancreatitis disease states. In addition, the finding of IL-17 signaling in CP could provide insight into the immune mechanisms underlying disease progression.

Passive monitoring by smart toilets for precision health

Smart toilets are a key tool for enabling precision health monitoring in the home, but such passive monitoring has ethical considerations.

Development of a Clinical Prediction Model for Diabetes in Chronic Pancreatitis: The PREDICT3c Study

OBJECTIVE

Diabetes that arises from chronic pancreatitis (CP) is associated with increased morbidity and mortality. Methods to predict which patients with CP are at greatest risk for diabetes are urgently needed. We aimed to examine independent risk factors for diabetes in a large cohort of patients with CP.

RESEARCH DESIGN AND METHODS

This cross-sectional study comprised 645 individuals with CP enrolled in the PROCEED study, of whom 276 had diabetes. We conducted univariable and multivariable regression analyses of potential risk factors for diabetes. Model performance was assessed by area under the receiver operating characteristic curve (AUROC) analysis, and accuracy was evaluated by cross validation. Exploratory analyses were stratified according to the timing of development of diabetes relative to the diagnosis of pancreatitis.

RESULTS

Independent correlates of diabetes in CP included risk factors for type 2 diabetes (older age, overweight/obese status, male sex, non-White race, tobacco use) as well as pancreatic disease-related factors (history of acute pancreatitis complications, nonalcoholic etiology of CP, exocrine pancreatic dysfunction, pancreatic calcification, pancreatic atrophy) (AUROC 0.745). Type 2 diabetes risk factors were predominant for diabetes occurring before pancreatitis, and pancreatic disease-related factors were predominant for diabetes occurring after pancreatitis.

CONCLUSIONS

Multiple factors are associated with diabetes in CP, including canonical risk factors for type 2 diabetes and features associated with pancreatitis severity. This study lays the groundwork for the future development of models integrating clinical and nonclinical data to identify patients with CP at risk for diabetes and identifies modifiable risk factors (obesity, smoking) on which to focus for diabetes prevention.

Prospective, Multi-Institutional, Real-Time Next-Generation Sequencing of Pancreatic Cyst Fluid Reveals Diverse Genomic Alterations That Improve the Clinical Management of Pancreatic Cysts

BACKGROUND & AIMS

Next-generation sequencing (NGS) of pancreatic cyst fluid is a useful adjunct in the assessment of patients with pancreatic cyst. However, previous studies have been retrospective or single institutional experiences. The aim of this study was to prospectively evaluate NGS on a multi-institutional cohort of patients with pancreatic cyst in real time.

METHODS

The performance of a 22-gene NGS panel (PancreaSeq) was first retrospectively confirmed and then within a 2-year timeframe, PancreaSeq testing was prospectively used to evaluate endoscopic ultrasound-guided fine-needle aspiration pancreatic cyst fluid from 31 institutions. PancreaSeq results were correlated with endoscopic ultrasound findings, ancillary studies, current pancreatic cyst guidelines, follow-up, and expanded testing (Oncomine) of postoperative specimens.

RESULTS

Among 1933 PCs prospectively tested, 1887 (98%) specimens from 1832 patients were satisfactory for PancreaSeq testing. Follow-up was available for 1216 (66%) patients (median, 23 months). Based on 251 (21%) patients with surgical pathology, mitogen-activated protein kinase/GNAS mutations had 90% sensitivity and 100% specificity for a mucinous cyst (positive predictive value [PPV], 100%; negative predictive value [NPV], 77%). On exclusion of low-level variants, the combination of mitogen-activated protein kinase/GNAS and TP53/SMAD4/CTNNB1/mammalian target of rapamycin alterations had 88% sensitivity and 98% specificity for advanced neoplasia (PPV, 97%; NPV, 93%). Inclusion of cytopathologic evaluation to PancreaSeq testing improved the sensitivity to 93% and maintained a high specificity of 95% (PPV, 92%; NPV, 95%). In comparison, other modalities and current pancreatic cyst guidelines, such as the American Gastroenterology Association and International Association of Pancreatology/Fukuoka guidelines, show inferior diagnostic performance. The sensitivities and specificities of VHL and MEN1/loss of heterozygosity alterations were 71% and 100% for serous cystadenomas (PPV, 100%; NPV, 98%), and 68% and 98% for pancreatic neuroendocrine tumors (PPV, 85%; NPV, 95%), respectively. On follow-up, serous cystadenomas with TP53/TERT mutations exhibited interval growth, whereas pancreatic neuroendocrine tumors with loss of heterozygosity of ≥3 genes tended to have distant metastasis. None of the 965 patients who did not undergo surgery developed malignancy. Postoperative Oncomine testing identified mucinous cysts with BRAF fusions and ERBB2 amplification, and advanced neoplasia with CDKN2A alterations.

CONCLUSIONS

PancreaSeq was not only sensitive and specific for various pancreatic cyst types and advanced neoplasia arising from mucinous cysts, but also reveals the diversity of genomic alterations seen in pancreatic cysts and their clinical significance.

Quantitative MRI of chronic pancreatitis: results from a multi-institutional prospective study, magnetic resonance imaging as a non-invasive method for assessment of pancreatic fibrosis (MINIMAP)

PURPOSE

To determine if quantitative MRI techniques can be helpful to evaluate chronic pancreatitis (CP) in a setting of multi-institutional study.

METHODS

This study included a subgroup of participants (n = 101) enrolled in the Prospective Evaluation of Chronic Pancreatitis for Epidemiologic and Translational Studies (PROCEED) study (NCT03099850) from February 2019 to May 2021. MRI was performed on 1.5 T using Siemens and GE scanners at seven clinical centers across the USA. Quantitative MRI parameters of the pancreas included T1 relaxation time, extracellular volume (ECV) fraction, apparent diffusion coefficient (ADC), and fat signal fraction. We report the diagnostic performance and mean values within the control (n = 50) and CP (n = 51) groups. The T1, ECV and fat signal fraction were combined to generate the quantitative MRI score (Q-MRI).

RESULTS

There was significantly higher T1 relaxation time; mean 669 ms (± 171) vs. 593 ms (± 82) (p = 0.006), ECV fraction; 40.2% (± 14.7) vs. 30.3% (± 11.9) (p < 0.001), and pancreatic fat signal fraction; 12.2% (± 5.5) vs. 8.2% (± 4.4) (p < 0.001) in the CP group compared to controls. The ADC was similar between groups (p = 0.45). The AUCs for the T1, ECV, and pancreatic fat signal fraction were 0.62, 0.72, and 0.73, respectively. The composite Q-MRI score improved the diagnostic performance (cross-validated AUC: 0.76).

CONCLUSION

Quantitative MR parameters evaluating the pancreatic parenchyma (T1, ECV fraction, and fat signal fraction) are helpful in the diagnosis of CP. A Q-MRI score that combines these three MR parameters improves diagnostic performance. Further studies are warranted with larger study populations including patients with acute and recurrent acute pancreatitis and longitudinal follow-ups.

T1 signal intensity ratio of the pancreas as an imaging biomarker for the staging of chronic pancreatitis

PURPOSE

Our purpose was to validate the T1 SIR (T1 score) as an imaging biomarker for the staging of CP in a large, multi-institutional, prospective study.

METHODS

The prospective study population included 820 participants enrolled in the PROCEED study from nine clinical centers between June 2017 and December 2021. A radiologist at each institution used a standardized method to measure the T1 signal intensity of the pancreas and the reference organs (spleen, paraspinal muscle, liver), which was used to derive respective T1 scores. Participants were stratified according to the seven mechanistic stages of chronic pancreatitis (MSCP 0-6) based on their clinical history, MRCP, and CT findings.

RESULTS

The mean pancreas-to-spleen T1 score was 1.30 in participants with chronic abdominal pain, 1.22 in those with acute or recurrent acute pancreatitis, and 1.03 in definite CP. After adjusting for covariates, we observed a linear, progressive decline in the pancreas-to-spleen T1 score with increasing MSCP from 0 to 6. The mean pancreas-to-spleen T1 scores were 1.34 (MSCP 0), 1.27 (MSCP 1), 1.21 (MSCP 2), 1.16 (MSCP 3), 1.18 (MSCP 4), 1.12 (MSCP 5), and 1.05 (MSCP 6) (p < 0.0001). The pancreas-to-liver and pancreas-to-muscle T1 scores showed less linear trends and wider confidence intervals.

CONCLUSION

The T1 score calculated by SIR of the pancreas-to-spleen shows a negative linear correlation with the progression of chronic pancreatitis. It holds promise as a practical imaging biomarker in evaluating disease severity in clinical research and practice.

High Prevalence of Osteopathy in Chronic Pancreatitis: A Cross-sectional Analysis From the PROCEED Study

BACKGROUND & AIMS

Chronic pancreatitis (CP) is associated with osteopathy (osteoporosis or osteopenia). However, existing literature is mostly limited to retrospective or administrative studies that have not clearly defined the prevalence and risk factors. Our aim was to identify patient- and disease-related associations with osteopathy in a prospective cohort study of CP.

METHODS

We studied 282 subjects with definitive CP enrolled in the PROCEED study who had a baseline dual-energy X-ray absorptiometry (DXA) scan. Osteopenia and osteoporosis were defined using the lowest T-scores. Clinical data were collected using standardized case report forms. Comparisons were performed with a multivariate logistic regression model with forward selection to identify risk factors for osteopathy.

RESULTS

The majority of subjects had osteopathy on DXA scan (56.0%; 17.0% osteoporosis; 39.0% osteopenia). Subjects with osteopathy had a higher prevalence of traumatic (40.0% vs 26.4%; P = .02) and spontaneous fractures (3.9% vs 0; P = .04). On multivariate analysis, older age (odds ratio [OR], 1.29 per 5 years; 95% confidence interval [CI], 1.15-1.45), female sex (OR, 3.08; 95% CI, 1.75-5.43), white race (OR, 2.68; 95% CI, 1.20-6.01), and underweight body mass index category (OR, 7.40; 95% CI, 1.56-34.99) were associated with higher probability of osteopathy. There were no significant associations between osteopathy and other patient and disease-related features of CP.

CONCLUSION

In the largest study of patients with CP who underwent DXA screening, the majority had osteopathy. There are overlapping risk factors with osteopathy in the general population, but the high prevalence in men and younger women supports the need for future investigations into the mechanisms of bone loss in CP.

CLINICALTRIALS

gov number, NCT03099850.

Management of Incidentally Detected Gallbladder Polyps: Society of Radiologists in Ultrasound Consensus Conference Recommendations

Gallbladder polyps (also known as polypoid lesions of the gallbladder) are a common incidental finding. The vast majority of gallbladder polyps smaller than 10 mm are not true neoplastic polyps but are benign cholesterol polyps with no inherent risk of malignancy. In addition, recent studies have shown that the overall risk of gallbladder cancer is not increased in patients with small gallbladder polyps, calling into question the rationale for frequent and prolonged follow-up of these common lesions. In 2021, a Society of Radiologists in Ultrasound, or SRU, consensus conference was convened to provide recommendations for the management of incidentally detected gallbladder polyps at US. See also the editorial by Sidhu and Rafailidis in this issue.

Design and Rationale for the Use of Magnetic Resonance Imaging Biomarkers to Predict Diabetes After Acute Pancreatitis in the Diabetes RElated to Acute Pancreatitis and Its Mechanisms Study: From the Type 1 Diabetes in Acute Pancreatitis Consortium

ABSTRACT

This core component of the Diabetes RElated to Acute pancreatitis and its Mechanisms (DREAM) study will examine the hypothesis that advanced magnetic resonance imaging (MRI) techniques can reflect underlying pathophysiologic changes and provide imaging biomarkers that predict diabetes mellitus (DM) after acute pancreatitis (AP). A subset of participants in the DREAM study will enroll and undergo serial MRI examinations using a specific research protocol. The aim of the study is to differentiate at-risk individuals from those who remain euglycemic by identifying parenchymal features after AP. Performing longitudinal MRI will enable us to observe and understand the natural history of post-AP DM. We will compare MRI parameters obtained by interrogating tissue properties in euglycemic, prediabetic, and incident diabetes subjects and correlate them with metabolic, genetic, and immunological phenotypes. Differentiating imaging parameters will be combined to develop a quantitative composite risk score. This composite risk score will potentially have the ability to monitor the risk of DM in clinical practice or trials. We will use artificial intelligence, specifically deep learning, algorithms to optimize the predictive ability of MRI. In addition to the research MRI, the DREAM study will also correlate clinical computed tomography and MRI scans with DM development.

Standard Operating Procedures for Biospecimen Collection, Processing, and Storage: From the Type 1 Diabetes in Acute Pancreatitis Consortium

ABSTRACT

Differences in methods for biospecimen collection, processing, and storage can yield considerable variability and error. Therefore, best practices for standard operating procedures are critical for successful discovery, development, and validation of disease biomarkers. Here, we describe standard operating procedures developed for biospecimen collection during the DREAM (Diabetes RElated to Acute pancreatitis and its Mechanisms) Study within the Type 1 Diabetes in Acute Pancreatitis Consortium. Notably, these protocols were developed using an integrative process based on prior consortium experience and with input from working groups with expertise in immunology, pancreatitis, and diabetes. Publication and adoption consistent biospecimen protocols will inform future studies and allow for better comparisons across different metabolic research efforts.

Rationale and Design for the Diabetes RElated to Acute Pancreatitis and Its Mechanisms Study: A Prospective Cohort Study From the Type 1 Diabetes in Acute Pancreatitis Consortium

ABSTRACT

Acute pancreatitis (AP) is a disease characterized by an acute inflammatory phase followed by a convalescent phase. Diabetes mellitus (DM) was historically felt to be a transient phenomenon related to acute inflammation; however, it is increasingly recognized as an important late and chronic complication. There are several challenges that have prevented precisely determining the incidence rate of DM after AP and understanding the underlying mechanisms. The DREAM (Diabetes RElated to Acute Pancreatitis and its Mechanisms) Study is a prospective cohort study designed to address these and other knowledge gaps to provide the evidence needed to screen for, prevent, and treat DM after AP. In the following article, we summarize literature regarding the epidemiology of DM after AP and provide the rationale and an overview of the DREAM study.

Novel Circulating and Tissue Monocytes as Well as Macrophages in Pancreatitis and Recovery

BACKGROUND AND AIMS

Acute pancreatitis (AP) is an inflammatory disease with mild to severe course that is associated with local and systemic complications and significant mortality. Uncovering inflammatory pathways that lead to progression and recovery will inform ways to monitor and/or develop effective therapies.

METHODS

We performed single-cell mass Cytometry by Time Of Flight (CyTOF) analysis to identify pancreatic and systemic inflammatory signals during mild AP (referred to as AP), severe AP (SAP), and recovery using 2 independent experimental models and blood from patients with AP and recurrent AP. Flow cytometric validation of monocytes subsets identified using CyTOF analysis was performed independently.

RESULTS

Ly6C+ inflammatory monocytes were the most altered cells in the pancreas during experimental AP, recovery, and SAP. Deep profiling uncovered heterogeneity among pancreatic and blood monocytes and identified 7 novel subsets during AP and recovery, and 6 monocyte subsets during SAP. Notably, a dynamic shift in pancreatic CD206+ macrophage population was observed during AP and recovery. Deeper profiling of the CD206+ macrophage identified 7 novel subsets during AP, recovery, and SAP. Differential expression analysis of these novel monocyte and CD206+ macrophage subsets revealed significantly altered surface (CD44, CD54, CD115, CD140a, CD196, podoplanin) and functional markers (interferon-γ, interleukin 4, interleukin 22, latency associated peptide-transforming growth factor-β, tumor necrosis factor-α, T-bet, RoRγt) that were associated with recovery and SAP. Moreover, a targeted functional analysis further revealed distinct expression of pro- and anti-inflammatory cytokines by pancreatic CD206+ macrophage subsets as the disease either progressed or resolved. Similarly, we identified heterogeneity among circulating classical inflammatory monocytes (CD14+CD16-) and novel subsets in patients with AP and recurrent AP.

CONCLUSIONS

We identified several novel monocyte/macrophage subsets with unique phenotype and functional characteristics that are associated with AP, recovery, and SAP. Our findings highlight differential innate immune responses during AP progression and recovery that can be leveraged for future disease monitoring and targeting.

Acute pancreatitis and diabetes mellitus: a review

Diabetes following acute pancreatitis (AP) is becoming increasingly recognized. It is unclear what subtype of diabetes mellitus (DM) occurs; however, type 3c diabetes mellitus (T3cDM) is gaining increasing recognition. T3cDM has differing pathophysiology than other subtypes of DM and therefore differing disease course and treatment. Current studies have examined the incidence and prevalence of DM following AP, and meta-analyses have shown around 15% develop DM at 1 year with an increasing proportion developing DM at 5 years. It has been observed that some patients have transient hyperglycemia following AP episode with a subset developing persistent impaired glucose metabolism; however, the exact timeline is not well defined. The data on risk factors for developing DM after AP is limited and mixed; however, it is likely that severity of AP may impact the propensity to develop DM. Screening guidelines have not been established following AP; however, screening 1-year post-event will likely capture a sizable proportion of newly developed DM. The endocrine and exocrine pancreas are closely linked, and studies have found significant overlap in dysfunction of both after AP. Finally, there are some data to suggest that diabetes predisposes patients to structural changes in the pancreas and increased risk of developing AP.

Imaging-Based Subtypes of Pancreatic Ductal Adenocarcinoma Exhibit Differential Growth and Metabolic Patterns in the Pre-Diagnostic Period: Implications for Early Detection

BACKGROUND

Previously, we characterized subtypes of pancreatic ductal adenocarcinoma (PDAC) on computed-tomography (CT) scans, whereby conspicuous (high delta) PDAC tumors are more likely to have aggressive biology and poorer clinical outcomes compared to inconspicuous (low delta) tumors. Here, we hypothesized that these imaging-based subtypes would exhibit different growth-rates and distinctive metabolic effects in the period prior to PDAC diagnosis.

MATERIALS AND METHODS

Retrospectively, we evaluated 55 patients who developed PDAC as a second primary cancer and underwent serial pre-diagnostic (T0) and diagnostic (T1) CT-scans. We scored the PDAC tumors into high and low delta on T1 and, serially, obtained the biaxial measurements of the pancreatic lesions (T0-T1). We used the Gompertz-function to model the growth-kinetics and estimate the tumor growth-rate constant (α) which was used for tumor binary classification, followed by cross-validation of the classifier accuracy. We used maximum-likelihood estimation to estimate initiation-time from a single cell (10^-6 mm³) to a 10 mm³ tumor mass. Finally, we serially quantified the subcutaneous-abdominal-fat (SAF), visceral-abdominal-fat (VAF), and muscles volumes (cm³) on CT-scans, and recorded the change in blood glucose (BG) levels. T-test, likelihood-ratio, Cox proportional-hazards, and Kaplan-Meier were used for statistical analysis and p-value <0.05 was considered significant.

RESULTS

Compared to high delta tumors, low delta tumors had significantly slower average growth-rate constants (0.024 month^-1 vs. 0.088 month^-1, p<0.0001) and longer average initiation-times (14 years vs. 5 years, p<0.0001). α demonstrated high accuracy (area under the curve (AUC)=0.85) in classifying the tumors into high and low delta, with an optimal cut-off of 0.034 month^-1. Leave-one-out-cross-validation showed 80% accuracy in predicting the delta-class (AUC=0.84). High delta tumors exhibited accelerated SAF, VAF, and muscle wasting (p <0.001), and BG disturbance (p<0.01) compared to low delta tumors. Patients with low delta tumors had better PDAC-specific progression-free survival (log-rank, p<0.0001), earlier stage tumors (p=0.005), and higher likelihood to receive resection after PDAC diagnosis (p=0.008), compared to those with high delta tumors.

CONCLUSION

Imaging-based subtypes of PDAC exhibit distinct growth, metabolic, and clinical profiles during the pre-diagnostic period. Our results suggest that heterogeneous disease biology may be an important consideration in early detection strategies for PDAC.

Unique circulating immune signatures for recurrent acute pancreatitis, chronic pancreatitis and pancreatic cancer: A pilot study of these conditions with and without diabetes

OBJECTIVE

This exploratory study seeks to identify distinct circulating immune signatures among patients having recurrent acute pancreatitis (RAP), chronic pancreatitis (CP), and pancreatic adenocarcinoma (PDAC).

METHODS

A retrospective analysis of human serum samples from collaborating institutions of the Consortium for the Study of Chronic Pancreatitis, Diabetes, and Pancreatic Cancer (CPDPC) was performed. Samples came from the North American Pancreatitis Studies 2 (NAPS2) cohort and the Pancreatic Adenocarcinoma Gene Environment Risk Study (PAGER) and were analyzed using a 62-plex Luminex assay in a blinded fashion. Group and pairwise comparisons were performed to identify unique immune signature panels and to calculate diagnostic utility using area under the curve analysis.

RESULTS

A total of 179 patients' samples were included: 41 controls, 40 CP, 78 PDAC and 20 RAP patients, of which 20 controls, 20 CP, and 58 PDAC patients had diabetes mellitus (DM). A unique immune signature panel could discriminate RAP, CP, and PDAC from controls with an AUC range from 0.77 to 0.86 (95% CI range: 0.64-0.94), RAP from CP, and CP from PDAC with an AUC of 0.77 (95% CI 0.64-0.90) and 0.76 (95% CI 0.67-0.86), respectively. Furthermore, an immune signature panel could also discriminate PDAC-DM from DM controls with an AUC of 0.96 (95% CI: 0.93-1.00) CONCLUSION: This study identifies unique immune analytes that may serve as novel diagnostic and predictive non-invasive biomarkers of RAP, CP, and PDAC. Further validation is warranted in prospective cohorts as developed by the CPDPC.

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.

Chronic pancreatitis changes in high-risk individuals for pancreatic ductal adenocarcinoma

BACKGROUND AND AIMS

Pancreatic intraepithelial neoplasia is associated with chronic pancreatitis (CP) changes on EUS. The objective of this study was to determine whether CP changes were more common in high-risk individuals (HRIs) than in control subjects and whether these changes differed among higher-risk subsets of HRIs.

METHODS

HRIs and control subjects were identified from an endoscopy database. HRIs were defined as having predisposing mutations or a family history (FH) of pancreatic ductal adenocarcinoma. HRIs were classified as vHRIs who met Cancer of the Pancreas Screening (CAPS) criteria for high risk and mHRIs who did not. Multivariable logistic regression was used to adjust for confounders and CP risk factors.

RESULTS

Sixty-five HRIs (44 vHRIs, 21 mHRIs) and 118 control subjects were included. HRIs were included for FH (25), Lynch syndrome (5), Peutz-Jeghers syndrome (2), and mutations in BRCA1/2 (26), PALB2 (3), ATM (3), and CDKN2A (1). After adjustment for relevant variables, HRIs were 16 times more likely to exhibit 3 or more CP changes than control subjects (95% confidence interval, 2.6-97.0; P = .003). HRIs were also more likely to have hypoechoic foci (odds ratio, 8.0; 95% confidence interval, 1.9-32.9; P = .004). vHRIs and mHRIs did not differ in frequency of 3 or more CP changes on EUS.

CONCLUSIONS

HRIs were more likely to exhibit CP changes and hypoechoic foci on EUS compared with control subjects. HRIs with these findings may require closer surveillance. HRIs who did or did not meet CAPS criteria did not differ with regard to CP findings, supporting a more inclusive approach to screening.

EUS and related technologies for the diagnosis and treatment of pancreatic disease: research gaps and opportunities-Summary of a National Institute of Diabetes and Digestive and Kidney Diseases workshop

A workshop was sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases to address the research gaps and opportunities in pancreatic EUS. The event occurred on July 26, 2017 in 4 sessions: (1) benign pancreatic diseases, (2) high-risk pancreatic diseases, (3) diagnostic and therapeutics, and (4) new technologies. The current state of knowledge was reviewed, with identification of numerous gaps in knowledge and research needs. Common themes included the need for large multicenter consortia of various pancreatic diseases to facilitate meaningful research of these entities; to standardize EUS features of different pancreatic disorders, the technique of sampling pancreatic lesions, and the performance of various therapeutic EUS procedures; and to identify high-risk disease early at the cellular level before macroscopic disease develops. The need for specialized tools and accessories to enable the safe and effective performance of therapeutic EUS procedures also was discussed.

Transgastric pancreatic necrosectomy-expedited return to prepancreatitis health

BACKGROUND

The best operative strategy for necrotizing pancreatitis remains controversial. Traditional surgical necrosectomy is associated with significant morbidity; endoscopic and percutaneous strategies require repeated interventions with prolonged hospitalizations. We have developed a transgastric approach to pancreatic necrosectomy to overcome the shortcomings of the other techniques described.

MATERIALS AND METHODS

Patients with necrotizing pancreatitis treated from 2009 to 2016 at an academic center were retrospectively reviewed. Open or laparoscopic transgastric necrosectomy was performed if the area of necrosis was walled-off and in a retrogastric position on cross-sectional imaging. Study endpoints included postoperative complications and mortality.

RESULTS

Forty-six patients underwent transgastric necrosectomy (nine open and 37 laparoscopic). Median (interquartile range) preoperative Acute Physiologic and Chronic Health Evaluation II score was 6 (3-12). Seventy percent of patients had >30% necrosis on preoperative imaging; infected necrosis was present in 35%. Median total length of stay (LOS) was 6 (3-12) d. No patient required a second operative debridement; four patients (9%) had short-term postoperative percutaneous drainage for residual fluid collections. Median follow-up was 1 y; there were no fistula or wound complications. Six patients (13%) had postoperative bleeding; five patients received treatment by image-guided embolization. There was one death in the cohort.

CONCLUSIONS

Transgastric pancreatic necrosectomy allows for effective debridement with a single definitive operation. When anatomically suitable, this operative strategy offers expedited recovery and avoids long-term morbidity associated with fistulas and prolonged drainage.

Global Protease Activity Profiling Provides Differential Diagnosis of Pancreatic Cysts

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Fukuoka and AGA Criteria Have Superior Diagnostic Accuracy for Advanced Cystic Neoplasms than Sendai Criteria

BACKGROUND

The aim of this study was to compare the American Gastroenterological Association guidelines (AGA criteria), the 2012 (Fukuoka criteria), and 2006 (Sendai criteria) International Consensus Guidelines for the diagnosis of advanced pancreatic cystic neoplasms.

METHODS

All patients who underwent surgical resection of a pancreatic cyst from August 2007 through January 2016 were retrospectively analyzed at a single tertiary academic center. Relevant clinical and imaging variables along with pathology results were collected to determine appropriate classification for each guideline. Advanced pancreatic cystic neoplasms were defined by the presence of either high-grade dysplasia or cystic adenocarcinoma. Diagnostic accuracy was measured by ROC analysis.

RESULTS

A total of 209 patients were included. Both the AGA and Fukuoka criteria had a higher diagnostic accuracy for advanced neoplastic cysts than the Sendai criteria: AGA ROC 0.76 (95% CI 0.69-0.81), Fukuoka ROC 0.78 (95% CI 0.74-0.82), and Sendai ROC 0.65 (95% CI 0.61-0.69) (p < 0.0001). There was no difference between the Fukuoka and the AGA criteria. While the sensitivity was higher in the Fukuoka criteria compared to the AGA criteria (97.7 vs. 88.6%), the specificity was higher in the AGA criteria compared to the Fukuoka criteria (62.4 vs. 58.2%).

CONCLUSIONS

In a surgical series of patients with pancreatic cysts, the AGA and Fukuoka criteria had superior diagnostic accuracy for advanced neoplastic cysts compared to the original Sendai criteria.

Acute pancreatitis patient registry to examine novel therapies in clinical experience (APPRENTICE): an international, multicenter consortium for the study of acute pancreatitis

Background

We have established a multicenter international consortium to better understand the natural history of acute pancreatitis (AP) worldwide and to develop a platform for future randomized clinical trials.

Methods

The AP patient registry to examine novel therapies in clinical experience (APPRENTICE) was formed in July 2014. Detailed web-based questionnaires were then developed to prospectively capture information on demographics, etiology, pancreatitis history, comorbidities, risk factors, severity biomarkers, severity indices, health-care utilization, management strategies, and outcomes of AP patients.

Results

Between November 2015 and September 2016, a total of 20 sites (8 in the United States, 5 in Europe, 3 in South America, 2 in Mexico and 2 in India) prospectively enrolled 509 AP patients. All data were entered into the REDCap (Research Electronic Data Capture) database by participating centers and systematically reviewed by the coordinating site (University of Pittsburgh). The approaches and methodology are described in detail, along with an interim report on the demographic results.

Conclusion

APPRENTICE, an international collaboration of tertiary AP centers throughout the world, has demonstrated the feasibility of building a large, prospective, multicenter patient registry to study AP. Analysis of the collected data may provide a greater understanding of AP and APPRENTICE will serve as a future platform for randomized clinical trials.

Cholestyramine as a promising, strong anion exchange resin for direct capture of genetic biomarkers from raw pancreatic fluids

The ability to capture cell-free DNA from the gastrointestinal tract, in a minimally invasive manner, could enhance our ability to diagnose gastrointestinal disease, or gain a better understanding of the spatial mapping of the intestinal microbiota. We, therefore, sought to identify a class of capture agents that could directly and efficiently sequester genetic material from intestinal fluids. As a particular case study, we examined the ability to capture DNA from pancreatic secretions, for potential application in enabling the sequestration of early, genetic biomarkers of pancreatic disease. We hypothesized that the cholestyramine series of strong cation exchange resins, which are FDA approved for the treatment of high cholesterol, may be capable of capturing DNA from pancreatic secretions. We identified a particular cholestyramine resin, DOWEX 1 × 2 100-200 mesh, which is able to efficiently capture and purify DNA from pancreatic fluid. Using only 200 μL of pancreatic secretions, we are able to recover 247 ± 182 ng of amplifiable human DNA, giving an estimated pancreatic fluid DNA content of 1.23 ± 0.91 ng/μL. To our knowledge, this is the first demonstration of a material that can effectively capture and purify DNA directly from untreated pancreatic fluids. Thus, our approach could hold high utility for the in vivo capture of DNA and disease biomarkers if incorporated into an appropriate sampling device. Biotechnol. Bioeng. 2017;114: 934-938. © 2016 Wiley Periodicals, Inc.

Neuroendocrine tumors of the pancreas: Degree of cystic component predicts prognosis

BACKGROUND

Although most pancreatic neuroendocrine tumors are solid, approximately 10% are cystic. Some studies have suggested that cystic pancreatic neuroendocrine tumors are associated with a more favorable prognosis.

METHODS

A retrospective review of all patients with pancreatic neuroendocrine tumors who underwent operative resection between 1999 and 2014 at a single academic medical center was performed. Based on cross-sectional imaging performed before operation, pancreatic neuroendocrine tumors were classified according to the size of the cystic component relative to the total tumor size: purely cystic (100%), mostly cystic (≥50%), mostly solid (<50%), and purely solid (0%). Clinicopathologic characteristics and recurrence-free survival were assessed between groups.

RESULTS

In the study, 214 patients met inclusion criteria: 8 with purely cystic tumors, 7 with mostly cystic tumors, 15 with mostly solid tumors, and 184 with purely solid tumors. The groups differed in terms of tumor size (1.5 ± 0.5, 3.0 ± 1.7, 3.7 ± 2.6, and 4.0 ± 3.5 cm), lymph node positivity (0%, 0%, 26.7%, and 34.2%), intermediate or high grade (0%, 16.7%, 20.0%, and 31.0%), synchronous liver metastases (0%, 14.3%, 20.0%, and 26.6%) and need for pancreaticoduodenectomy (0%, 0%, 6.7%, and 25.0%), respectively. No cases of purely cystic pancreatic neuroendocrine tumors were associated with synchronous liver or lymph node metastasis, intermediate/high grade, recurrence, or death due to disease. Among patients presenting without metastatic disease, 10-year recurrence-free survival was 100% in patients with purely and mostly cystic tumors versus 53.0% in patients with purely and mostly solid tumors; however, this difference did not reach statistical significance.

CONCLUSION

Pancreatic neuroendocrine tumors demonstrate a spectrum of biologic behavior with an increasing cystic component being associated with more favorable clinicopathologic features and prognosis. Purely cystic pancreatic neuroendocrine tumors may represent 1 subset that can be safely observed without immediate resection.

Short turn radius colonoscope in an anatomical model: Retroflexed withdrawal and detection of hidden polyps

AIM: To evaluate the new RetroView™ colonoscope and compare its ability to detect simulated polyps “hidden” behind colonic folds with that of a conventional colonoscope, utilizing anatomic colon models.

METHODS: Three anatomic colon models were prepared, with twelve simulated polyps “hidden” behind haustral folds and five placed in easily viewed locations in each model. Five blinded endoscopists examined two colon models in random order with the conventional or RetroView™ colonoscope, utilizing standard withdrawal technique. The third colon model was then examined with the RetroView™ colonoscope withdrawn initially in retroflexion and then in standard withdrawal. Polyp detection rates during standard and retroflexed withdrawal of the conventional and RetroView™ colonoscopes were determined. Polyp detection rates for combined standard and retroflexed withdrawal (combination withdrawal) with the RetroView™ colonoscope were also determined.

RESULTS: For hidden polyps, retroflexed withdrawal using the RetroView™ colonoscope detected more polyps than the conventional colonoscope in standard withdrawal (85% vs 12%, P = 0.0001). For hidden polyps, combination withdrawal with the RetroView™ colonoscope detected more polyps than the conventional colonoscope in standard withdrawal (93% vs 12%, P≤ 0.0001). The RetroView™ colonoscope in “combination withdrawal” was superior to other methods in detecting all (hidden + easily visible) polyps, with successful detection of 80 of 85 polyps (94%) compared to 28 (32%) polyps detected by the conventional colonoscope in standard withdrawal (P < 0.0001) and 67 (79%) polyps detected by the RetroView™ colonoscope in retroflexed withdrawal alone (P < 0.01). Continuous withdrawal of the colonoscope through the colon model while retroflexed was achieved by all endoscopists. In a post-test survey, four out of five colonoscopists reported that manipulation of the colonoscope was easy or very easy.

CONCLUSION: In simulated testing, the RetroView™ colonoscope increased detection of hidden polyps. Combining standard withdrawal with retroflexed withdrawal may become the new paradigm for “complete screening colonoscopy”.

Laparoscopic transgastric necrosectomy for the management of pancreatic necrosis

BACKGROUND

Traditional open necrosectomy for pancreatic necrosis is associated with significant morbidity and mortality. Although minimally invasive techniques have been described and offer some promise, each has considerable limitations. This study assesses the safety and effectiveness of laparoscopic transgastric necrosectomy (LTN), a novel technique for the management of necrotizing pancreatitis.

STUDY DESIGN

Between 2009 and 2013, patients with retrogastric pancreatic necrosis requiring debridement were evaluated for LTN. Debridement was performed via a laparoscopic transgastric approach using 2 to 3 ports and the wide cystgastrostomy left open. Patient demographics, disease severity, operative characteristics, and outcomes were collected and analyzed.

RESULTS

Twenty-one patients (13 men, median age 54 years; interquartile range [IQR] 46 to 62 years) underwent LTN during the study period. The duration between pancreatitis onset and debridement was 65 days (IQR 53 to 124 years). Indications for operation included infection (7 patients) and persistent unwellness (14 patients). Median duration of LTN was 170 minutes (IQR 136 to 199 minutes); there were no conversions. Control of the necrosis was achieved via the single procedure in 19 of 21 patients. Median postoperative hospital stay was 5 days (IQR 3 to 14 days) and the majority (71%) of patients experienced no (n = 9) or only minor postoperative complications (n = 6) by Clavien-Dindo grade. Complications of Clavien-Dindo grade 3 or higher developed in 6 patients, including 1 death (5%). With a median follow-up of 11 months (IQR 7 to 22 months), none of the patients required additional operative debridement or had pancreatic/enteric fistulae or wound complications develop.

CONCLUSIONS

Laparoscopic transgastric necrosectomy is a novel, minimally invasive technique for the management of pancreatic necrosis that allows for debridement in a single operation. When feasible, LTN can reduce the morbidity associated with traditional open necrosectomy and avoid the limitations of other minimally invasive approaches.

Metabolomic-derived novel cyst fluid biomarkers for pancreatic cysts: glucose and kynurenine

BACKGROUND

Better pancreatic cyst fluid biomarkers are needed.

OBJECTIVE

To determine whether metabolomic profiling of pancreatic cyst fluid would yield clinically useful cyst fluid biomarkers.

DESIGN

Retrospective study.

SETTING

Tertiary-care referral center.

PATIENTS

Two independent cohorts of patients (n = 26 and n = 19) with histologically defined pancreatic cysts.

INTERVENTION

Exploratory analysis for differentially expressed metabolites between (1) nonmucinous and mucinous cysts and (2) malignant and premalignant cysts was performed in the first cohort. With the second cohort, a validation analysis of promising identified metabolites was performed.

MAIN OUTCOME MEASUREMENTS

Identification of differentially expressed metabolites between clinically relevant cyst categories and their diagnostic performance (receiver operating characteristic [ROC] curve).

RESULTS

Two metabolites had diagnostic significance-glucose and kynurenine. Metabolomic abundances for both were significantly lower in mucinous cysts compared with nonmucinous cysts in both cohorts (glucose first cohort P = .002, validation P = .006; and kynurenine first cohort P = .002, validation P = .002). The ROC curve for glucose was 0.92 (95% confidence interval [CI], 0.81-1.00) and 0.88 (95% CI, 0.72-1.00) in the first and validation cohorts, respectively. The ROC for kynurenine was 0.94 (95% CI, 0.81-1.00) and 0.92 (95% CI, 0.76-1.00) in the first and validation cohorts, respectively. Neither could differentiate premalignant from malignant cysts. Glucose and kynurenine levels were significantly elevated for serous cystadenomas in both cohorts.

LIMITATIONS

Small sample sizes.

CONCLUSION

Metabolomic profiling identified glucose and kynurenine to have potential clinical utility for differentiating mucinous from nonmucinous pancreatic cysts. These markers also may diagnose serous cystadenomas.