Increased serum resistin concentration in patients with chronic pancreatitis: possible cause of pancreatic fibrosis

Circulating Biomarkers Involved in the Development of and Progression to Chronic Pancreatitis-A Literature Review

Chronic pancreatitis (CP) is the end-stage of continuous inflammation and fibrosis in the pancreas evolving from acute- to recurrent acute-, early, and, finally, end-stage CP. Currently, prevention is the only way to reduce disease burden. In this setting, early detection is of great importance. Due to the anatomy and risks associated with direct sampling from pancreatic tissue, most of our information on the human pancreas arises from circulating biomarkers thought to be involved in pancreatic pathophysiology or injury. The present review provides the status of circulating biomarkers involved in the development of and progression to CP.

Sarcopenia in Chronic Pancreatitis - Prevalence, Diagnosis, Mechanisms and Potential Therapies

PURPOSE OF REVIEW

To investigate the prevalence, pathogenesis, diagnosis, clinical sequelae, and management of sarcopenia to improve mortality and quality of life in those with Chronic Pancreatitis.

RECENT FINDINGS

Sarcopenia is prevalent in chronic pancreatitis and can significantly affect clinical outcomes. Sarcopenia is prevalent in chronic pancreatitis. While effects on some clinical outcomes is has been shown, there is a significant gap in knowledge regarding effects on outcomes, pathophysiology, and options for management.

Local and Systemic Expression of Immunomodulatory Factors in Chronic Pancreatitis

Inflammatory and fibrotic events that drive chronic pancreatitis (CP) are likely orchestrated via signaling of soluble cytokines and chemokines systemically and within the pancreas. However, a comprehensive summary of the expression of such factors during CP has not been reported to date. This information is important given continued interest in targeting cytokines that influence CP pathogenesis. Reported data on the expression change of soluble immunomodulatory factors in human CP patients were identified via a literature search using a single search term. Thirty-one articles meeting the prespecified inclusion criteria were identified to generate a compiled data summary. Compiled data demonstrated up-regulation of several factors in the blood or pancreas microenvironment of CP patients. Nine factors were elevated in both compartments, including fractalkine, IFN-γ, interleukin 1β, IL-6, IL-8, macrophage inhibitory cytokine 1, neutrophil gelatinase-associated lipocalin, transforming growth factor β, and tumor necrosis factor α. Most up-regulated factors could be classified into one of several functional groups, including inflammation, chemotaxis, angiogenesis, bone remodeling, extracellular matrix remodeling, and pain. After further validation, these factors may be used as biomarkers for disease diagnosis and identification of comorbidities, or as potential therapeutic targets.

Monocyte chemoattractant protein-1, transforming growth factor-beta1, nerve growth factor, resistin and hyaluronic acid as serum markers: comparison between recurrent acute and chronic pancreatitis

BACKGROUND

Diagnostic parameters that can predict the presence of chronic pancreatitis (CP) in patients with recurrent pain due to pancreatitis would help to direct appropriate therapy. This study aimed to compare the serum levels of monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-beta1 (TGF-beta1), nerve growth factor (NGF), resistin and hyaluronic acid (HA) in patients with recurrent acute pancreatitis (RAP) and CP to assess their ability to differentiate the two conditions.

METHODS

Levels of serum markers assessed by enzyme-linked immunosorbent assay (ELISA) were prospectively compared in consecutive patients with RAP, CP and in controls, and stepwise discriminant analysis was performed to identify the markers differentiating RAP from CP.

RESULTS

One hundred and thirteen consecutive patients (RAP=32, CP=81) and 78 healthy controls were prospectively enrolled. The mean (SD) age of the patients was 32.0 (14.0) years; 89 (78.8%) were male. All markers were significantly higher in CP patients than in the controls (P<0.001); MCP-1, NGF and HA were significantly higher in RAP patients than in the controls (P<0.001). Stepwise discriminant analysis showed significant difference (P=0.002) between RAP and CP for resistin with an accuracy of 61.9%, discriminant scores of ≤-0.479 and ≥0.189 indicating RAP and CP, respectively. The other markers had no differential value between RAP and CP.

CONCLUSION

Serum resistin is a promising marker to differentiate between RAP and CP and needs validation in future studies, especially in those with early CP.

Resistin is not an appropriate biochemical marker to predict severity of acute pancreatitis: A case-controlled study

AIM: To assess levels of serum resistin upon hospital admission as a predictor of acute pancreatitis (AP) severity.

METHODS: AP is both a common and serious disease, with severe cases resulting in a high mortality rate. Several predictive inflammatory markers have been used clinically to assess severity. This prospective study collected data from 102 patients who were diagnosed with an initial acute biliary pancreatitis between March 2010 and February 2013. Measurements of body mass index (BMI) and waist circumference (WC) were obtained and serum resistin levels were analyzed at the time of hospital admission using enzyme-linked immunosorbent assay. Additionally, resistin levels were measured from a control group after matching gender, BMI and age.

RESULTS: A total of 102 patients (60 females and 42 males) were diagnosed with acute gallstone-induced pancreatitis. The mean age was 45 years, and mean BMI value was 30.5 kg/m² (Obese, class I). Twenty-two patients (21.6%) had severe AP, while eighty-eight patients had mild pancreatitis (78.4%). Our results showed that BMI significantly correlated with pancreatitis severity (P = 0.007). Serum resistin did not correlate with BMI, weight or WC. Furthermore, serum resistin was significantly higher in patients with AP compared to control subjects (P < 0.0001). The mean resistin values upon admission were 17.5 ng/mL in the severe acute biliary pancreatitis group and 16.82 ng/mL in the mild AP group (P = 0.188), indicating that resistin is not an appropriate predictive marker of clinical severity.

CONCLUSION: We demonstrate that obesity is a risk factor for developing severe AP. Further, although there is a correlation between serum resistin levels and AP at the time of hospital admission, resistin does not adequately serve as a predictive marker of clinical severity.

Fibrosis reduces severity of acute-on-chronic pancreatitis in humans

BACKGROUND & AIMS

Acute pancreatitis (AP) and chronic pancreatitis (CP) share etiologies, but AP can be more severe and is associated with a higher rate of mortality. We investigated features of CP that protect against severe disease. The amount of intrapancreatic fat (IPF) is increased in obese patients and fibrosis is increased in patients with CP, so we studied whether fibrosis or fat regulate severity of AP attacks in patients with CP.

METHODS

We reviewed records from the University of Pittsburgh Medical Center/Presbyterian Hospital Autopsy Database (1998-2008) for patients with a diagnosis of AP (n = 23), CP (n = 35), or both (AP-on-CP; n = 15). Pancreatic histology samples from these patients and 50 randomly selected controls (no pancreatic disease) were analyzed, and IPF data were correlated with computed tomography data. An adipocyte and acinar cell Transwell coculture system, with or without collagen type I, was used to study the effects of fibrosis on acinar-adipocyte interactions. We studied the effects of nonesterified fatty acids (NEFAs) and adipokines on acinar cells in culture.

RESULTS

Levels of IPF were significantly higher in nonobese patients with CP than in nonobese controls. In patients with CP or AP-on-CP, areas of IPF were surrounded by significantly more fibrosis than in controls or patients with AP. Fat necrosis-associated peri-fat acinar necrosis (PFAN, indicated by NEFA spillage) contributed to most of the necrosis observed in samples from patients with AP; however, findings of peri-fat acinar necrosis and total necrosis were significantly lower in samples from patients with CP or AP-on-CP. Fibrosis appeared to wall off the fat necrosis and limit peri-fat acinar necrosis, reducing acinar necrosis. In vitro, collagen I limited the lipolytic flux between acinar cells and adipocytes and prevented increases in adipokines in the acinar compartment. This was associated with reduced acinar cell necrosis. However, NEFAs, but not adipokines, caused acinar cell necrosis.

CONCLUSIONS

Based on analysis of pancreatic samples from patients with CP, AP, or AP-on-CP and in vitro studies, fibrosis reduces the severity of acute exacerbations of CP by reducing lipolytic flux between adipocytes and acinar cells.

Role of adipocytokines and its correlation with endocrine pancreatic function in patients with pancreatic cancer

INTRODUCTION

Some authors suggest that adipocytokines contribute to the induction of pancreatic carcinogenesis as well as the development of endocrine insufficiency.

AIMS

We evaluate the circulating concentrations of leptin, resistin and visfatin in patients with newly diagnosed pancreatic cancer (PC) and relationship between serum adipocytokines level and clinicopathological features of PC. Moreover the usefulness of those adipocytokines as possible biomarkers of endocrine pancreatic function in PC has been assessed.

METHODS

The pilot study group consisted of 45 individuals (mean age 65.6 ± 11.5 years, BMI 21.8 ± 3.4 kg/m(2)) with newly diagnosed PC (within last 1-3 months) and 13 healthy individuals with age, gender and BMI matched to the study group. Among PC patients 18 (40%) had recently diagnosed diabetes. Fasting plasma leptin, resistin, visfatin concentrations were determined with ELISA (R&D Systems, Phoenix Pharmaceuticals) and insulin by RIA (DakoCytomation).

RESULTS

Patients with PC as compared to controls had significantly lower plasma leptin (40.6 ± 21.3 vs 63.2 ± 16.3 pg/mL; p < 0,0008). In contrast PC patients showed more than six fold higher level of resistin (126.2 ± 143.2 vs 18.9 ± 7.2 ng/mL; p < 0.009) than controls. The median plasma visfatin was 2.8 ± 1.8 ng/mL, which was not significantly different from the controls (3.8 ± 1.1 ng/mL). When PC patients with and without diabetes were considered separately, plasma leptin concentrations among nondiabetic patients were slightly, but not significantly higher (44.6 ± 21.0) as compared to diabetics (34.5 ± 20.7). Moreover there was no difference between visfatin and resistin level in PC, among patients with and without diabetes. No significant differences between serum level of leptin, visfatin and resistin and age, gender, BMI, smoking status, tumor localization, distant metastases and pain has been found.

CONCLUSION

The results of this study confirm previous findings that patients with newly diagnosed pancreatic cancer are characterized with lower level of leptin. This pilot study showed significantly higher resistin concentrations in patients with PC in comparison to healthy controls, which may be helpful in PC early diagnosis. Changes in leptin and resistin level in PC are not likely related to endocrine disorders.

Serum levels of adipocyte fatty acid-binding protein are decreased in chronic pancreatitis

OBJECTIVE

Chronic pancreatitis (CP) is associated with an increased risk for diabetes mellitus and vascular disease. Adipocyte fatty acid-binding protein (AFABP) is a novel adipokine that is independently associated with the metabolic syndrome and cardiovascular disease. In the current study, we investigated serum AFABP levels in CP patients compared with sex- and body mass index-matched controls.

METHODS

Adipocyte fatty acid-binding protein was determined with enzyme-linked immunosorbent assay in control subjects (n = 60) and diabetic as well as nondiabetic CP (n = 60) patients and correlated to clinical and biochemical measures of glucose and lipid metabolism, as well as renal function in both groups.

RESULTS

Median serum AFABP levels were significantly lower in CP patients compared with controls (12.5 vs 20.9 μg/L, P = 0.003). Furthermore, body mass index, sex, and CP independently predicted circulating AFABP. In contrast, no significant difference in circulating AFABP could be demonstrated between diabetic and nondiabetic CP patients.

CONCLUSIONS

Circulating AFABP is paradoxically lower in CP patients and does not depend on pancreatic diabetes. Our data do not support a role of circulating AFABP in metabolic and vascular risk in CP patients.

Increased serum chemerin concentration in patients with chronic pancreatitis

BACKGROUND

Chemerin is a potent chemoattractant for chemokine-like receptor 1 expressing cells and is involved in inflammatory and immune processes that play an important role in chronic pancreatitis.

AIM

To test the hypothesis that serum chemerin concentration may be affected in chronic pancreatitis patients and that chemerin can influence the course of chronic pancreatitis by increasing profibrotic cytokine production.

METHODS

Serum concentrations of chemerin and the major cytokines involved in pancreatic fibrosis such as platelet-derived growth factor BB and transforming growth factor β-1 were determined by ELISA in samples from 40 nondiabetic and 28 diabetic male patients with chronic pancreatitis of alcoholic origin and 40 age-matched healthy controls.

RESULTS

Serum concentrations of chemerin were increased both in nondiabetic and diabetic chronic pancreatitis patients compared to controls. Moreover, in chronic pancreatitis patients a positive correlation was found between serum chemerin and platelet-derived growth factor BB as well as transforming growth factor β-1 concentrations.

CONCLUSIONS

The results indicate for the first time that: (a) chronic pancreatitis in humans is associated with an increased serum chemerin concentration and (b) serum chemerin concentration correlates with serum concentrations of the major profibrotic cytokines. Elevated level of chemerin, by stimulating macrophage infiltration of the pancreas, might lead to overproduction of platelet-derived growth factor BB and transforming growth factor β-1 and, consequently, to pancreatic fibrosis.

Human pancreatic polypeptide in a phospholipid-based micellar formulation

PURPOSE

Pancreatic polypeptide (PP) has important glucoregulatory functions and thereby holds significance in the treatment of diabetes and obesity. However, short plasma half-life and aggregation propensity of PP in aqueous solution, limits its therapeutic application. To address these issues, we prepared and characterized a formulation of PP in sterically stabilized micelles (SSM) that protects and stabilizes PP in its active conformation.

METHODS

PP-SSM was prepared by incubating PP with SSM dispersion in buffer. Peptide-micelle association and freeze-drying efficacy of the formulation was characterized in phosphate buffers with or without sodium chloride using dynamic light scattering, fluorescence spectroscopy and circular dichroism. The degradation kinetics of PP-SSM in presence of proteolytic enzyme was determined using HPLC and bioactivity of the formulation was evaluated by in vitro cAMP inhibition study.

RESULTS

PP self-associated with SSM and this interaction was influenced by presence/absence of sodium chloride in the buffer. The formulation was effectively lyophilized, demonstrating feasibility for its long-term storage. The stability of peptide against proteolytic degradation was significantly improved and PP in SSM retained its bioactivity in vitro.

CONCLUSIONS

Self-association of PP with phospholipid micelles addressed the delivery issues of the peptide. This nanomedicine should be further developed for the treatment of diabetes.

Decreased serum essential and aromatic amino acids in patients with chronic pancreatitis

AIM: To investigate the influence of chronic pancreatitis (CP) on serum concentrations of amino acids.

METHODS: Thirty-five male patients with alcoholic CP and 21 healthy male subjects were examined. Serum concentrations of amino acids were assayed by ion-pair high-performance liquid chromatography with mass detection.

RESULTS: Serum glutamate concentration was increased in CP patients as compared to controls. In contrast, serum concentrations of glutamine, histidine, tyrosine, proline, tryptophan and threonine were significantly decreased in CP patients. A trend towards decreasing concentrations of serum lysine, alanine, methionine and valine as well as for total serum amino acids was observed. The sum of aromatic and the sum of essential amino acid concentrations were significantly lower in CP patients than in controls.

CONCLUSION: CP leads to decreased serum concentrations of several amino acids, such as essential and aromatic serum amino acids, most likely due to decreased exocrine function.