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179 result(s) for "Conwell, Darwin L."
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American College of Gastroenterology Guidelines: Management of Acute Pancreatitis
Acute pancreatitis (AP), defined as acute inflammation of the pancreas, is one of the most common diseases of the gastrointestinal tract leading to hospital admission in the United States. It is important for clinicians to appreciate that AP is heterogenous, progressing differently among patients and is often unpredictable. While most patients experience symptoms lasting a few days, almost one-fifth of patients will go on to experience complications, including pancreatic necrosis and/or organ failure, at times requiring prolonged hospitalization, intensive care, and radiologic, surgical, and/or endoscopic intervention. Early management is essential to identify and treat patients with AP to prevent complications. Patients with biliary pancreatitis typically will require surgery to prevent recurrent disease and may need early endoscopic retrograde cholangiopancreatography if the disease is complicated by cholangitis. Nutrition plays an important role in treating patients with AP. The safety of early refeeding and importance in preventing complications from AP are addressed. This guideline will provide an evidence-based practical approach to the management of patients with AP.
Chronic Pancreatitis: Managing a Difficult Disease
Chronic pancreatitis is characterized by progressive, irreversible morphologic and functional changes that are most commonly attributed to environmental insults, particularly when there is a genetic or anatomic predisposition. Heavy alcohol use and cigarette smoking are the most common environmental risk factors, but both may be absent. Antecedent episodes of acute pancreatitis occur in about half of patients. Abdominal pain is the most common symptom and requires a tailored approach depending on the anatomic changes in the pancreas. Other clinical manifestations include diabetes mellitus, exocrine pancreatic insufficiency, metabolic bone disease, pancreatic cancer, and anatomic complications. Current disease management is centered on risk factor reduction and screening for and treating disease complications. There are no current therapies to delay or retard disease progression, but there are ongoing efforts to more fully understand the natural history of chronic pancreatitis and underlying mechanisms of disease. These studies are expected to provide insights that will transform our approach to disease management and provide increased hope to patients.
Quality of Life in Chronic Pancreatitis is Determined by Constant Pain, Disability/Unemployment, Current Smoking, and Associated Co-Morbidities
Chronic pancreatitis (CP) has a profound independent effect on quality of life (QOL). Our aim was to identify factors that impact the QOL in CP patients. We used data on 1,024 CP patients enrolled in the three NAPS2 studies. Information on demographics, risk factors, co-morbidities, disease phenotype, and treatments was obtained from responses to structured questionnaires. Physical and mental component summary (PCS and MCS, respectively) scores generated using responses to the Short Form-12 (SF-12) survey were used to assess QOL at enrollment. Multivariable linear regression models determined independent predictors of QOL. Mean PCS and MCS scores were 36.7±11.7 and 42.4±12.2, respectively. Significant (P<0.05) negative impact on PCS scores in multivariable analyses was noted owing to constant mild-moderate pain with episodes of severe pain or constant severe pain (10 points), constant mild-moderate pain (5.2), pain-related disability/unemployment (5.1), current smoking (2.9 points), and medical co-morbidities. Significant (P<0.05) negative impact on MCS scores was related to constant pain irrespective of severity (6.8-6.9 points), current smoking (3.9 points), and pain-related disability/unemployment (2.4 points). In women, disability/unemployment resulted in an additional 3.7 point reduction in MCS score. Final multivariable models explained 27% and 18% of the variance in PCS and MCS scores, respectively. Etiology, disease duration, pancreatic morphology, diabetes, exocrine insufficiency, and prior endotherapy/pancreatic surgery had no significant independent effect on QOL. Constant pain, pain-related disability/unemployment, current smoking, and concurrent co-morbidities significantly affect the QOL in CP. Further research is needed to identify factors impacting QOL not explained by our analyses.
Diagnostic performance of endoscopic ultrasound for detection of pancreatic malignancy following an indeterminate multidetector CT scan: a systemic review and meta-analysis
Background Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis in part due to delayed diagnosis. Even with advances in cross-sectional imaging, small pancreatic malignancies can be missed. We sought to determine the performance of endoscopic ultrasound (EUS) in those without an obvious mass on multi-detector CT scan (MDCT), but with clinical suspicion for pancreatic malignancy. Methods Multiple databases were systematically searched to identify studies that assessed the diagnostic performance of EUS after negative or inconclusive pancreatic protocol MDCT for detection of pancreatic malignancy when clinically suspected. A total of four studies met the inclusion criteria. The point estimates in each study were compared to the summary pooled estimates of sensitivity and specificity with the aid of forest plots. Funnel plots and Egger’s test were employed to evaluate possible publication bias. Results EUS-guided fine needle aspiration was performed in all studies. EUS was performed in 206 subjects with a clinical suspicion of a pancreatic mass but with an indeterminate MDCT. A pancreatic mass (mean size 21 ± 1.2 mm) was identified in 70% ( n  = 144) of the subjects, and 42.2% ( n  = 87) were diagnosed with PDAC. The pooled estimates of EUS for diagnosing pancreatic malignancy in the setting of an indeterminate MDCT were a sensitivity of 85% (95% CI 69–94%), specificity of 58% (95% CI 40–74%), positive predictive value of 77% (69–84%), negative predictive value of 66% (95% CI 53–77%), and an accuracy of 75% (95% CI 67–82). The summary area under the ROC curve was 0.80 (95% CI 0.52–0.89). The funnel plots and Egger’s test did not show a significant publication bias. Conclusions The yield of EUS is comparatively higher for the diagnosis of a pancreatic malignancy in patients with suspected cancer, but a non-diagnostic MDCT. Importantly, the majority of the lesions missed on CT represent PDAC, in which early diagnosis is essential.
Inhibition of Jak/STAT signaling reduces the activation of pancreatic stellate cells in vitro and limits caerulein-induced chronic pancreatitis in vivo
Chronic pancreatitis (CP) is a fibro-inflammatory disease leading to pain, maldigestion, and pancreatic insufficiency. No therapeutic options exist due to a limited understanding of the biology of CP pathology. Recent findings implicate pancreatic stellate cells (PSC) as prominent mediators of inflammatory and fibrotic processes during CP. Here, we utilized primary and immortalized PSC obtained from mice and patients with CP or pancreatic cancer to examine the effect of Jak/STAT and MAPK pathway inhibition in vitro . The well-characterized caerulein model of CP was used to assess the therapeutic efficacy of Jak1/2 inhibition in vivo . Treatment of cultured PSC with the Jak1/2 inhibitor ruxolitinib reduced STAT3 phosphorylation, cell proliferation, and expression of alpha-smooth muscle actin (α-SMA), a marker of PSC activation. Treatment with the MAPK inhibitor, MEK162, had less consistent effects on PSC proliferation and no impact on activation. In the caerulein-induced murine model of CP, administration of ruxolitinib for one week significantly reduced biomarkers of inflammation and fibrosis. These data suggest that the Jak/STAT pathway plays a prominent role in PSC proliferation and activation. In vivo treatment with the Jak1/2 inhibitor ruxolitinib reduced the severity of experimental CP, suggesting that targeting Jak/STAT signaling may represent a promising therapeutic strategy for CP.
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)
PurposeTo determine if quantitative MRI techniques can be helpful to evaluate chronic pancreatitis (CP) in a setting of multi-institutional study.MethodsThis 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).ResultsThere 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).ConclusionQuantitative 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.
Validation of Demographics, Etiology, and Risk Factors for Chronic Pancreatitis in the USA: A Report of the North American Pancreas Study (NAPS) Group
Background/Objectives Our aim was to validate recent epidemiologic trends and describe the distribution of TIGAR-O risk factors in chronic pancreatitis (CP) patients. Methods The NAPS-2 Continuation and Validation (NAPS2-CV) study prospectively enrolled 521 CP patients from 13 US centers from 2008 to 2012. CP was defined by definitive changes in imaging, endoscopy, or histology. Data were analyzed after stratification by demographic factors, physician-defined etiology, participating center, and TIGAR-O risk factors. Results Demographics and physician-defined etiology in the NAPS2-CV study were similar to the original NAPS2 study. Mean age was 53 years (IQR 43, 62) with 55% males and 87% white. Overall, alcohol was the single most common etiology (46%) followed by idiopathic etiology (24%). Alcohol etiology was significantly more common in males, middle-aged (35–65 years), and non-whites. Females and elderly (≥65 years) were more likely to have idiopathic etiology, while younger patients (<35 years) to have genetic etiology. Variability in etiology was noted by participating centers (e.g., alcohol etiology ranged from 27 to 67% among centers enrolling ≥25 patients). Smoking was the most commonly identified (59%) risk factor followed by alcohol (53%), idiopathic (30%), obstructive (19%), and hyperlipidemia (13%). The presence of multiple TIGAR-O risk factors was common, with 1, 2, ≥3 risk factors observed in 27.6, 47.6, and 23.6% of the cohort, respectively. Conclusion Our data validate the current epidemiologic trends in CP. Alcohol remains the most common physician-defined etiology, while smoking was the most commonly identified TIGAR-O risk factor. Identification of multiple risk factors suggests CP to be a complex disease.
Racial Differences in the Clinical Profile, Causes, and Outcome of Chronic Pancreatitis
Racial differences in susceptibility and progression of pancreatitis have been reported in epidemiologic studies using administrative or retrospective data. There has been little study, however, on the clinical profile, causes, and outcome of chronic pancreatitis (CP) in black patients. We analyzed data on black patients with CP prospectively enrolled in the multicenter North American Pancreatitis Studies from 26 US centers during the years 2000-2014. CP was defined by definitive evidence on imaging studies or histology. Information on demographics, etiology, risk factors, disease phenotype, treatment, and perceived effectiveness was obtained from responses to detailed questionnaires completed by both patients and physicians. Of the 1,159 patients enrolled, 248 (21%) were black. When compared with whites, blacks were significantly more likely to be male (60.9 vs. 53%), ever (88.2 vs. 71.8%), or current smokers (64.2 vs. 45.9%), or have a physician-defined alcohol etiology (77 vs. 41.9%). There was no overall difference in the duration of CP although for alcoholic CP, blacks had a longer duration of disease (8.6 vs. 6.97 years; P=0.02). Blacks were also significantly more likely to have advanced changes on pancreatic morphology (calcifications (63.3 vs. 55.2%), atrophy (43.2 vs. 34.6%), pancreatic ductal stricture or dilatation (72.6 vs. 65.5%) or common bile duct stricture (18.6 vs. 8.2%)) and function (endocrine insufficiency 39.9 vs. 30.2%). Moreover, the prevalence of any (94.7 vs. 83%), constant (62.6 vs. 51%), and severe (78.4 vs. 65.8%) pain and disability (35.1 vs. 21.4%) were significantly higher in blacks. Observed differences were in part related to variances in etiology and duration of disease. No differences in medical or endoscopic treatments were seen between races although prior cholecystectomy (31.1 vs. 19%) was more common in white patients. Differences were observed between blacks and whites in the underlying cause, morphologic expression, and pain characteristics of CP, which in part are explained by the underlying risk factor(s) with alcohol and tobacco being much more frequent in black patients as well as disease duration.
Clinical risk factors for sarcopenia in acute and chronic pancreatitis
Background Sarcopenia is common in chronic pancreatitis (CP) and has been associated with unfavorable outcomes; however, it is not well studied in acute pancreatitis (AP). Aims To evaluate risk factors for sarcopenia among individuals with AP or CP. Methods A cross sectional analysis was performed among subjects with AP or CP seen in a tertiary care Pancreas Clinic. TeraRecon software was used to calculate the cross-sectional area of skeletal muscle, visceral fat, and subcutaneous fat at the level of the L3 vertebrae. Sarcopenia was classified using sex-specific skeletal muscle index. Univariate and multivariate logistic regressions were performed to assess differences between groups and associations with sarcopenia. Results A total of 49 subjects with AP and 54 subjects with CP were included. Sarcopenia was more frequently observed in CP compared to AP (83.3% vs. 46.9%, p  < 0.001). The multivariate logistic regression demonstrated CP, male sex, increased age, and decreased subcutaneous fat were independently associated with sarcopenia. Conclusion Sarcopenia is observed in both CP and AP. In addition to traditional risk factors (including male sex, older age, and decreased subcutaneous fat), CP is independently associated with sarcopenia. Further investigations are necessary to gain deeper insights into sarcopenia pathogenesis, which could inform potential intervention strategies.
CD200 promotes immunosuppression in the pancreatic tumor microenvironment
BackgroundA significant challenge to overcome in pancreatic ductal adenocarcinoma (PDAC) is the profound systemic immunosuppression that renders this disease non-responsive to immunotherapy. Our supporting data provide evidence that CD200, a regulator of myeloid cell activity, is expressed in the PDAC microenvironment. Additionally, myeloid-derived suppressor cells (MDSC) isolated from patients with PDAC express elevated levels of the CD200 receptor (CD200R). Thus, we hypothesize that CD200 expression in the PDAC microenvironment limits responses to immunotherapy by promoting expansion and activity of MDSC.MethodsImmunofluorescent staining was used to determine expression of CD200 in murine and human PDAC tissue. Flow cytometry was utilized to test for CD200R expression by immune populations in patient blood samples. In vivo antibody blocking of CD200 was conducted in subcutaneous MT-5 tumor-bearing mice and in a genetically engineered PDAC model (KPC-Brca2 mice). Peripheral blood mononuclear cells (PBMC) from patients with PDAC were analyzed by single-cell RNA sequencing. MDSC expansion assays were completed using healthy donor PBMC stimulated with IL-6/GM-CSF in the presence of recombinant CD200 protein.ResultsWe found expression of CD200 by human pancreatic cell lines (BxPC3, MiaPaca2, and PANC-1) as well as on primary epithelial pancreatic tumor cells and smooth muscle actin+ stromal cells. CD200R expression was found to be elevated on CD11b+CD33+HLA-DRlo/− MDSC immune populations from patients with PDAC (p=0.0106). Higher expression levels of CD200R were observed in CD15+ MDSC compared with CD14+ MDSC (p<0.001). In vivo studies demonstrated that CD200 antibody blockade limited tumor progression in MT-5 subcutaneous tumor-bearing and in KPC-Brca2 mice (p<0.05). The percentage of intratumoral MDSC was significantly reduced in anti-CD200 treated mice compared with controls. Additionally, in vivo blockade of CD200 can also significantly enhance the efficacy of PD-1 checkpoint antibodies compared with single antibody therapies (p<0.05). Single-cell RNA sequencing of PBMC from patients revealed that CD200R+ MDSC expressed genes involved in cytokine signaling and MDSC expansion. Further, in vitro cytokine-driven expansion and the suppressive activity of human MDSC was enhanced when cocultured with recombinant CD200 protein.ConclusionsThese results indicate that CD200 expression in the PDAC microenvironment may regulate MDSC expansion and that targeting CD200 may enhance activity of checkpoint immunotherapy.