Interleukins in acute pancreatitis

Heparanase in Acute Pancreatitis

Acute pancreatitis (AP) is one of the most common diseases in gastroenterology, affecting 2% of all hospitalized patients. Nevertheless, neither the etiology nor the pathophysiology of the disease is fully characterized, and no specific or effective treatment has been developed. Heparanase (Hpa) is an endoglycosidase that cleaves heparan sulfate (HS) side chains of heparan sulfate proteoglycans (HSPGs) into shorter oligosaccharides, activity that is highly implicated in cell invasion associated with cancer metastasis and inflammation. Given that AP is a typical inflammatory disease, we investigated whether Hpa plays a role in AP. Our results provide keen evidence that Hpa expression and activity are significantly increased following cerulein-induced AP in wild type mice. In parallel to the classic manifestations of AP, namely elevation of amylase and lipase levels, pancreas edema and inflammation as well as induction of cytokines and signaling molecules, have been detected in this experimental model of the disease. Noteworthy, these features were far more profound in transgenic mice overexpressing heparanase (Hpa-Tg), suggesting that these mice can be utilized as a model system to reveal the molecular mechanism by which Hpa functions in AP. Further support for the involvement of Hpa in the pathogenesis of AP emerged from our observation that treatment of experimental AP with PG545 or SST0001(= Ronepastat), two potent Hpa inhibitors, markedly attenuated the biochemical, histological and immunological manifestations of the disease. Hpa, therefore, emerges as a potential new target in AP, and Hpa inhibitors are hoped to prove beneficial in AP along with their promising efficacy as anti-cancer compounds.

A Mini-Review on the Effect of Docosahexaenoic Acid (DHA) on Cerulein-Induced and Hypertriglyceridemic Acute Pancreatitis

Acute pancreatitis refers to the sudden inflammation of the pancreas. It is associated with premature activation and release of digestive enzymes into the pancreatic interstitium and systemic circulation, resulting in pancreatic tissue autodigestion and multiple organ dysfunction, as well as with increased cytokine production, ultimately leading to deleterious local and systemic effects. Although mechanisms involved in pathogenesis of acute pancreatitis have not been completely elucidated, oxidative stress is regarded as a major risk factor. In human acute pancreatitis, lipid peroxide levels in pancreatic tissues increase. Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (C22:6n-3), exerts anti-inflammatory and antioxidant effects on various cells. Previous studies have shown that DHA activates peroxisome proliferator-activated receptor-γ and induces catalase, which inhibits oxidative stress-mediated inflammatory signaling required for cytokine expression in experimental acute pancreatitis using cerulein. Cerulein, a cholecystokinin analog, induces intra-acinar activation of trypsinogen in the pancreas, which results in human acute pancreatitis-like symptoms. Therefore, DHA supplementation may be beneficial for preventing or inhibiting acute pancreatitis development. Since DHA reduces serum triglyceride levels, addition of DHA to lipid-lowering drugs like statins has been investigated to reduce hypertriglyceridemic acute pancreatitis. However, high DHA concentrations increase cytosolic Ca²⁺, which activates protein kinase C and may induce hyperlipidemic acute pancreatitis. In this review, effect of DHA on cerulein-induced and hypertriglyceridemic acute pancreatitis has been discussed. The relation of high concentration of DHA to hyperlipidemic acute pancreatitis has been included.

Docosahexaenoic Acid Inhibits Cerulein-Induced Acute Pancreatitis in Rats

Oxidative stress is an important regulator in the pathogenesis of acute pancreatitis (AP). Reactive oxygen species induce activation of inflammatory cascades, inflammatory cell recruitment, and tissue damage. NF-κB regulates inflammatory cytokine gene expression, which induces an acute, edematous form of pancreatitis. Protein kinase C δ (PKCδ) activates NF-κB as shown in a mouse model of cerulein-induced AP. Docosahexaenoic acid (DHA), an ω-3 fatty acid, exerts anti-inflammatory and antioxidant effects in various cells and tissues. This study investigated whether DHA inhibits cerulein-induced AP in rats by assessing pancreatic edema, myeloperoxidase activity, levels of lipid peroxide and IL-6, activation of NF-κB and PKCδ, and by histologic observation. AP was induced by intraperitoneal injection (i.p.) of cerulein (50 μg/kg) every hour for 7 h. DHA (13 mg/kg) was administered i.p. for three days before AP induction. Pretreatment with DHA reduced cerulein-induced activation of NF-κB, PKCδ, and IL-6 in pancreatic tissues of rats. DHA suppressed pancreatic edema and decreased the abundance of lipid peroxide, myeloperoxidase activity, and inflammatory cell infiltration into the pancreatic tissues of cerulein-stimulated rats. Therefore, DHA may help prevent the development of pancreatitis by suppressing the activation of NF-κB and PKCδ, expression of IL-6, and oxidative damage to the pancreas.

Interleukin-6: An Early Predictive Marker for Severity of Acute Pancreatitis

Background and Aims:

Interleukin (IL)-6, IL-8, IL-10, and C-reactive protein (CRP) have been evaluated for predicting outcomes of acute pancreatitis. However, there is considerable variation in their performance among different studies. We evaluate their accuracy in predicting progression to severe pancreatitis.

Materials and Methods:

Serum IL-6, IL-8, IL-10, and CRP levels were measured within 24 h of admission in forty patients of clinically predicted severe acute pancreatitis (SAP). Persistent organ failure (>48 h) defined SAP. The performance of inflammatory markers was evaluated in predicting the progression of pancreatitis.

Results:

IL-6 ≥28.90 pg/mL had a sensitivity of 62.86%, specificity of 80%, positive predictive value (PPV) of 95.65%, LR+ of 3.1429, LR− of 0.4643, and diagnostic odds ratio (DOR) of 6.7692; IL-8 ≥88.70 pg/mL had a sensitivity of 60%, specificity of 80%, PPV of 95.45%, LR+ of 3.000, LR− of 0.5000, and DOR of 6.000; IL-10 ≤5.70 pg/mL had DOR of 0.2647, sensitivity of 51.43%, specificity of 20%, PPV of 81.82%, LR+ of 0.6429, and LR− of 2.4286. CRP ≥110.00 mg/L had DOR of 2.3636, sensitivity of 37.14%, specificity of 80%, PPV of 92.86%, LR+ of 1.8571, and LR of 0.7857.

Conclusions:

IL-6 ≥28.90 pg/mL, measured within 48 h of onset is the best among the tested biomarkers in this study for predicting the progression to severe pancreatitis.

The adipocytokine resistin stimulates the production of proinflammatory cytokines TNF-α and IL-6 in pancreatic acinar cells via NF-κB activation

BACKGROUND

Resistin, an adipocytokine secreted by fat tissues, has been associated with the inflammatory response, though its role in inflammation during acute pancreatitis (AP) remains unclear.

OBJECTIVE

The proinflammatory response following acinar cell injury impacts pancreatitis severity, necessitating better understanding of functional consequences associated with pancreatic acinar cell resistin exposure and resultant effects on proinflammatory signaling.

METHODS

Amylase-secreting rat pancreatic acinar AR42J cells were subjected to 1, 10, or 100 ng/ml recombinant rat resistin treatments. Cytotoxicity was evaluated by amylase secretion and lactate dehydrogenase (LDH) release. Tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6) mRNA and protein expressions were determined by real-time real time-PCR and enzyme-linked immunosorbent assay, respectively. Nuclear NF-κB p65 subunit protein level was measured by western blotting.

RESULTS

Significantly increased amylase secretion and LDH release was observed in the 100 ng/ml resistin treatment (p<0.01). Both TNF-α and IL-6 protein expression levels increased in a concentration-dependent manner when treated with resistin. Pretreatment of resistin- treated AR42J cells with the NF-κB inhibitor PDTC, which decreases the NF-κB p65 subunit protein expression levels in the nuclei, produced significantly lower mRNA expression levels for both TNF-α and IL-6 compared with those produced by resistin-treated cells (p<0.01).

CONCLUSIONS

Resistin exhibits some cytotoxic activity in rat pancreatic acinar AR42J cells and stimulates proinflammatory cytokine TNF-α and IL-6 production via NF-κB activation. Thus, overproduction of obesity-related circulating resistin and associated lowgrade inflammation may result in mild injury to pancreatic acini, increasing AP severity and risk.

5-lipoxygenase deficiency reduces acetaminophen-induced hepatotoxicity and lethality

5-Lipoxygenase (5-LO) converts arachidonic acid into leukotrienes (LTs) and is involved in inflammation. At present, the participation of 5-LO in acetaminophen (APAP)-induced hepatotoxicity and liver damage has not been addressed. 5-LO deficient (5-LO⁻/⁻) mice and background wild type mice were challenged with APAP (0.3-6 g/kg) or saline. The lethality, liver damage, neutrophil and macrophage recruitment, LTB₄, cytokine production, and oxidative stress were assessed. APAP induced a dose-dependent mortality, and the dose of 3 g/kg was selected for next experiments. APAP induced LTB4 production in the liver, the primary target organ in APAP toxicity. Histopathological analysis revealed that 5-LO⁻/⁻ mice presented reduced APAP-induced liver necrosis and inflammation compared with WT mice. APAP-induced lethality, increase of plasma levels of aspartate aminotransferase and alanine aminotransferase, liver cytokine (IL-1β, TNF-α , IFN- γ, and IL-10), superoxide anion, and thiobarbituric acid reactive substances production, myeloperoxidase and N-acetyl-β-D-glucosaminidase activity, Nrf2 and gp91(phox) mRNA expression, and decrease of reduced glutathione and antioxidant capacity measured by 2,2'-azinobis(3-ethylbenzothiazoline 6-sulfonate) assay were prevented in 5-LO⁻/⁻ mice compared to WT mice. Therefore, 5-LO deficiency resulted in reduced mortality due to reduced liver inflammatory and oxidative damage, suggesting 5-LO is a promising target to reduce APAP-induced lethality and liver inflammatory/oxidative damage.

Combined effects of chronic and acute ethanol on pancreatic injury and microcirculation

OBJECTIVES

Aim of the study was to investigate pancreatic microcirculatory and histopathological changes in rats after chronic ethanol liquid diet feeding.

METHODS

To investigate the influence of chronic alcohol exposition (CAE) on the pancreas, rats were fed with either Lieber-DeCarli (LDC) control diet or LDC alcohol diet for 2, 4, or 6 weeks and received additionally an acute ethanol administration (AEA) for 90 minutes. Intravital microscopy was performed at baseline, 45 minutes, and 90 minutes after starting AEA. Pancreatic perfusion and leukocyte adhesion were assessed, and pancreatic damage was evaluated by histology.

RESULTS

Capillary perfusion was reduced in all animals after AEA. After previous CAE, there was a significant increase in leukocyte adhesion compared to control groups (P < 0.05). Most importantly, leukocyte adhesions were already increased at baseline after CAE and before the acute bolus was infused (P < 0.05). Moreover, only animals that received LDC alcohol diet developed mild histological changes consisting of pancreatic edema and vacuoles, whereas those that received AEA alone did not. Histological changes and cytokine levels correlated with the duration of prior CAE.

CONCLUSIONS

Long-term alcohol intake activates endothelium and sensitizes the pancreas for inflammatory reactions leading to an increased likelihood of a clinically evident episode of acute pancreatitis.

Plasmapheresis to treat hypertriglyceridemia in a child with diabetic ketoacidosis and pancreatitis

A 10-year-old girl presented with diabetic ketoacidosis, shock, and severe abdominal pain. She was found to have acute pancreatitis and acute kidney injury after shock resuscitation and severe persistent hypertriglyceridemia. The severe hypertriglyceridemia was treated with 1 course of plasmapheresis, which corrected the triglyceride level and was temporally associated with improvement of the abdominal pain and renal dysfunction. Diabetes is known to contribute to an elevated triglyceride level, especially in the setting of an underlying lipid disorder. However, no such disorders were found in this patient. To the best of our knowledge, this is the first report of a pediatric patient presenting with the triad of severe hypertriglyceridemia, diabetic ketoacidosis, and pancreatitis treated successfully with plasmapheresis.

Admission levels of soluble CD137 are increased in patients with acute pancreatitis and are associated with subsequent complications

The progression of acute pancreatitis to necrotizing pancreatitis which often results in high morbidity and mortality is difficult to predict. Here we report that serum concentrations of sCD137 are increased in patients with acute pancreatitis. Admission levels and 10-day median sCD137 levels positively correlate with markers of biliary pancreatitis and the 10-day sCD137 median is significantly higher in metabolic than in alcoholic pancreatitis. Serum concentrations of sCD137 at time of admission and the 10-day median of sCD137 correlate with the Ranson and APACHE II disease scores but not with the radiological Balthazar and Schroeder scores that reflect pancreatic and peripancreatic necrosis. Further, sCD137 levels correlate with the probability of complications and lethality. The association of sCD137, a product of activated T cells, with the severity of acute pancreatitis suggests that T cells contribute to the pathogenesis of acute pancreatitis.

Admission visfatin levels predict pancreatic and peripancreatic necrosis in acute pancreatitis and correlate with clinical severity

OBJECTIVES

Adipocytes of peripancreatic and intrapancreatic adipose tissue secret adipocytokines such as leptin, adiponectin, and resistin. For resistin, a role as an early predictor of peripancreatic necrosis and clinical severity in acute pancreatitis has been reported. It was the aim of this study to investigate whether the adipocytokine visfatin is able to serve as an early marker predicting peripancreatic necrosis and clinical severity.

METHODS

A total of 50 patients (20 females and 30 males) with acute pancreatitis were included in this noninterventional, prospective, and monocentric cohort study on diagnostic accuracy. Clinical severity was classified by the Ranson score and APACHE-II (Acute Physiology and Chronic Health Evaluation II) score. Pancreatic and peripancreatic necrosis were quantified by the computed tomography-based Balthazar score, the Schroeder score, and the pancreatic necrosis score. Visfatin was measured at admission and daily for 10 days by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Visfatin values were significantly and positively correlated with clinical severity (APACHE-II score and Ranson score) and with clinical end points such as death and need for interventions. Admission visfatin levels were significantly elevated in patients with higher pancreatic and extrapancreatic necrosis scores. It was shown by receiver operator characteristics that admission visfatin concentration provides a positive predictive value of 93.3% in predicting the extent of peripancreatic necrosis (area under the curve (AUC): 0.89, P<0.001, sensitivity: 93.3%, specificity: 81.8%, likelihood ratio: 5.1, post-test probability: 93%) by using a cutoff value of 1.8 ng/ml.

CONCLUSIONS

Admission visfatin concentration serves as an early predictive marker of peripancreatic necrosis and clinical severity in acute pancreatitis. Visfatin may have potential for clinical use as a new and diagnostic serum marker.

Lycopene inhibits IL-6 expression in cerulein-stimulated pancreatic acinar cells

Reactive oxygen species (ROS) are known to be involved in the pathogenesis of acute and chronic pancreatitis. The cholecystokinin (CCK) analog cerulein causes pathophysiological, morphological, and biochemical events similar to those observed in human acute pancreatitis. The oxidant-sensitive transcription factor NF-κB plays a critical role in the development of cerulein pancreatitis by regulating the expression of pro-inflammatory cytokines in the pancreas. Lycopene has an anti-oxidant effect in various cells. In the present study, we investigated whether cerulein induces NF-κB activation and IL-6 expression in pancreatic acinar cells and whether lycopene inhibits these events. NF-κB-DNA-binding activity was determined by electrophoretic mobility shift assay, and mRNA expression was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR analyses. The IL-6 concentration in the medium was determined by enzyme-linked immunosorbent assay. Our results showed that cerulein induced IL-6 expression in a time-dependent manner. NF-κB-DNA-binding activity and intracellular levels of ROS in pancreatic acinar cells were increased by cerulein. Lycopene inhibited the cerulein-induced increase in intracellular ROS, NF-κB activation, and IL-6 expression in pancreatic acinar cells in a dose-dependent manner. In conclusion, lycopene may be beneficial in the prevention and/or treatment of acute pancreatitis by inhibiting the activation of NF-κB and the expression of inflammatory cytokines through reduction in intracellular levels of ROS in pancreatic acinar cells.

Admission resistin levels predict peripancreatic necrosis and clinical severity in acute pancreatitis

OBJECTIVES

Peripancreatic necrosis determines clinical severity in acute pancreatitis. Early markers predicting peripancreatic necrosis and clinical severity are lacking. Because adipocytes of peripancreatic adipose tissue secret highly active adipocytokines, the aim of the study was to investigate whether adipocytokines are able to serve as early markers predicting peripancreatic necrosis and clinical severity.

METHODS

A total of 50 patients (20 women, 30 men) with acute pancreatitis were included in this noninterventional, prospective, and monocentric cohort study on diagnostic accuracy. Clinical severity was classified by the Ranson score and the APACHE (Acute Physiology And Chronic Health Evaluation) II score. Pancreatic and peripancreatic necrosis were quantified by using the computed tomography-based Balthazar score, the Schroeder score, and the pancreatic necrosis score. Adiponectin, leptin, and resistin were measured at admission and daily for at least 10 days by enzyme-linked immunosorbent assay.

RESULTS

In contrast to admission C-reactive protein values, admission resistin values were significantly correlated with clinical severity and even with clinical end points such as death and need for interventions. Admission resistin levels were significantly elevated in patients with higher pancreatic and extrapancreatic necrosis scores. It was shown by receiver-operator characteristics that admission resistin concentration provides a positive predictive value of 89% in predicting the extent of peripancreatic necrosis (area under the curve, 0.8; P=0.002; sensitivity, 80%; specificity, 70%) by using a cutoff value of 11.9 ng/ml.

CONCLUSIONS

Admission resistin concentration serves as an early predictive marker of peripancreatic necrosis and clinical severity in acute pancreatitis. Resistin may have potential for clinical use as a new and diagnostic serum marker.

Aggravation of acute pancreatitis by heparan sulfate in mice

OBJECTIVE

Systemic inflammatory response syndrome (SIRS) is responsible for pancreatitis-associated mortality, but its initiating events are poorly understood. Possible candidates may be endogenous substances, which have previously been shown to mediate inflammatory responses. The aim of this study was to investigate whether SIRS could be exaggerated by heparan sulfate (HS) in acute pancreatitis (AP).

MATERIAL AND METHODS

AP was induced in mice by cerulein injection and HS was administered one hour after the final cerulein injection. The severity of pancreatitis was assessed by serum amylase activity, pancreatic edema, and pancreatic myeloperoxidase (MPO) activity. Systemic inflammation was evaluated by assessing lung injury and by measuring serum levels of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6. Cytokine levels were also measured in pancreas and lung tissues.

RESULTS

HS did not worsen the pancreatic injury induced by cerulein. In contrast, HS exacerbated the systemic inflammation as measured by augmented lung MPO activity, increased lung TNF-alpha and IL-6 levels, and elevated serum IL-6 levels.

CONCLUSIONS

Our results indicate a potential role for HS in propagating pancreatic inflammation from a local process to a systemic response and thus suggest the possibility that blockade of HS might improve the outcome of SIRS in AP.

Cytokine genotypes in acute pancreatitis: association with etiology, severity, and cytokine levels in blood

The circumstances that determine how acute pancreatitis (AP) becomes severe are unknown. Differences in cytokine genetic encoding may determine the severity or influence the etiology of AP. This article investigates the relationship between different polymorphisms of tumor necrosis factor alpha (TNF-alpha), interleukin 1 (IL-1), IL-1 receptor antagonist, IL-6, and IL-10 with the severity and etiology of AP and the serum levels of the cytokine encoded.

METHODS

Patients with AP were included prospectively. Severity of the disease was determined according to Atlanta classification. Serum levels of these cytokines were determined within the first 72 hours after the onset of symptoms. The following polymorphisms were determined by polymerase chain reaction: IL-1a -889, IL-1b +3954, IL-1b -511, variable number tandem repeats, IL-6 -174, IL-6 -597, IL-10 -592, TNF-alpha 308, TNF-alpha 238, and TNF-B250.

RESULTS

Eighty-four patients were included. The GA genotype of the TNF-alpha 238 polymorphism was associated with more frequent respiratory failure and shock than the GG genotype. Gallstone pancreatitis was associated with the CC genotype of the IL-6 -174 CC polymorphism.

CONCLUSIONS

AG genotype of the TNF-alpha 238 polymorphism is associated with organic failure in patients with AP. The CC genotype of the IL-6 174 polymorphism is associated with biliary etiology of acute pancreatitis.

From acute pancreatitis to end-organ injury: mechanisms of acute lung injury

BACKGROUND

Multi-organ dysfunction, and in particular lung injury, is often responsible for the unfavorable outcome of patients with severe acute pancreatitis. Understanding of the mechanisms by which local inflammation in the pancreas leads to end-organ injury is crucial for the development of new therapeutic strategies.

METHODS

A MEDLINE search was performed with the terms "acute pancreatitis," "lung injury," "inflammatory response," "SIRS," and "multi-organ dysfunction." Pertinent articles were selected for analysis.

RESULTS

Modulation of the inflammatory response using a combination of immunomodulatory agents may decrease the incidence of severe pancreatitis-related acute lung injury and acute respiratory distress syndrome.

CONCLUSION

Clinical trials are of utmost importance to establish the validity of such strategies.

Potential of adipocytokines in predicting peripancreatic necrosis and severity in acute pancreatitis: pilot study

BACKGROUND AND AIM

Severe acute pancreatitis is characterized by lipase-induced peripancreatic fat cell necrosis. Because adipocytes secret several highly active molecules, the aim of the present study was to investigate the hypothesis that adipocytokines could serve as potential markers predicting peripancreatic necrosis and severity in acute pancreatitis.

METHODS

A total of 23 patients (11 females, 12 males) with acute pancreatitis were included and a computed tomography (CT) examination was available in 20 patients. Balthazar score, Schröder score, pancreatic necrosis score, Ranson score and APACHE II score were calculated, correlated with biochemical parameters and analyzed using receiver-operator characteristics (ROC) analysis. Adipocytokine serum levels were measured daily by enzyme-linked immunosorbent assay (ELISA) over 10 days after admission.

RESULTS

Resistin and leptin were significantly elevated in patients with severe pancreatitis and were correlated with a radiological scoring system for extrapancreatic necrosis. Whereas resistin correlated positively with clinical scoring systems, time until discharge and the need for interventions, leptin was correlated positively with C-reactive protein (CRP) levels. Resistin levels measured on the day of admittance had a positive predictive value of 93.3% (cut-off: >6.95 ng/mL) in predicting a Schröder score >3.

CONCLUSION

Resistin, and to a lesser extent leptin, but not adiponectin levels are novel potential markers for extrapancreatic necrosis and severity of acute pancreatitis and should therefore be tested in larger cohorts of patients.

Blood serum levels of proinflammatory cytokines in patients with different degrees of biliary pancreatitis

BACKGROUND

Proinflammatory cytokines play a fundamental role in the local and systemic inflammatory responses in the initial stages of acute biliary pancreatitis (ABP) and in the development of severe forms of the disease.

OBJECTIVES

The aim of the present study was to assess the systemic release of proinflammatory cytokines and to characterize differences between patients with mild ABP (MABP) and severe ABP (SABP).

PATIENTS AND METHODS

In the current study, 54 patients with MABP were compared with 14 patients with SABP. Serum levels of tumour necrosis factor-alpha, interleukin (IL)-1beta, IL-6, IL-8 and IL-12p40 were measured every second day after admission for one week.

RESULTS

The tumour necrosis factor-alpha level was similar in all days of analysis in patients with MABP but was lower compared with SABP patients. The level of IL-1beta was higher at admission in patients with MABP. The level of IL-6 peaked on admission day in both groups, but in patients with SABP, the obtained values were higher. The level of IL-8 on admission day was slightly higher in patients with MABP and systematically decreased when measured on the following days (the third, fifth and seventh days of the study). An increased level of IL-8 during the third, fifth and seventh days of the investigation was seen in SABP patients. The level of IL-12p40 was slightly higher in patients with MABP on the day of admission.

CONCLUSIONS

The levels of some proinflammatory cytokines are higher in patients with SABP than in patients with MABP. The most consistent difference between the two groups was that the levels of IL-6 were significantly higher in patients with SABP throughout the study. Serum concentration of IL-6 may be helpful as a marker of severity and outcome of ABP.

Substance P treatment stimulates chemokine synthesis in pancreatic acinar cells via the activation of NF-kappaB

Acinar cell injury early in acute pancreatitis leads to a local inflammatory reaction and to the subsequent systemic inflammatory response, which may result in multiple organ dysfunction and death. Inflammatory mediators, including chemokines and substance P (SP), are known to play a crucial role in the pathogenesis of acute pancreatitis. It has been shown that pancreatic acinar cells produce the chemokine monocyte chemoattractant protein-1 (MCP-1) in response to caerulein hyperstimulation, demonstrating that acinar-derived MCP-1 is an early mediator of inflammation in acute pancreatitis. Similarly, SP levels in the pancreas and pancreatic acinar cell expression of neurokinin-1 receptor, the primary receptor for SP, are both increased during secretagogue-induced experimental pancreatitis. This study aims to examine the functional consequences of exposing mouse pancreatic acinar cells to SP and to determine whether it leads to proinflammatory signaling, such as production of chemokines. Exposure of mouse pancreatic acini to SP significantly increased synthesis of MCP-1, macrophage inflammatory protein-1alpha (MIP-1alpha), as well as MIP-2. Furthermore, SP also increased NF-kappaB activation. The stimulatory effect of SP was specific to chemokine synthesis through the NF-kappaB pathway, since the increase in chemokine production was completely attenuated when pancreatic acini were pretreated with the selective NF-kappaB inhibitor NF-kappaB essential modulator-binding domain peptide. This study shows that SP-induced chemokine synthesis in mouse pancreatic acinar cells is NF-kappaB dependent.

Role of adipose tissue as an inflammatory organ in human diseases

Reviews on the inflammatory role of adipose tissue outside the field of metabolism are rare. There is increasing evidence provided by numerous basic research studies from nearly all internal medicine subspecializations that adipocytes and adipocytokines are involved in primary inflammatory processes and diseases. Therefore, it is the aim of the present review to discuss and to summarize the current knowledge on the inflammatory role of adipocytokines and special types of regional adipocytes such as retroorbital, synovial, visceral, subdermal, peritoneal, and bone marrow adipocytes in internal medicine diseases. Future clinical and therapeutic implications are discussed.

Inhibitory effect of Patrinia scabiosaefolia on acute pancreatitis

AIM: To investigate the effect of Patrinia scabiosaefolia (PS) on the cholecystokinin (CCK) octapeptide- induced acute pancreatitis (AP) in rats.

METHODS: Wistar rats weighing 240-260 g were divided into three groups: (1) Normal saline-treated group; (2) treatment with PS at 100 mg/kg group, in which PS was administered orally, followed by subcutaneous administration of 75 µg/kg CCK octapeptide three times after 1, 3 and 5 h, and this whole procedure was repeated for 5 d; (3) treatment with saline group, in which the protocols were the same as in treatment group with PS. We determined the pancreatic weight/body weight ratio, the levels of pancreatic HSP60, HSP72 and the secretion of pro-inflammatory cytokines. Repeated CCK octapeptide treatment resulted in the typical laboratory findings of experimentally induced pancreatitis.

RESULTS: PS reduced the pancreatic weight/body weight ratio, the levels of serum amylase and lipase, and inhibited expressions of pro-inflammatory cytokines in the CCK octapeptide-induced AP. Furthermore, PS pretreatment increased the pancreatic levels of HSP60 and HSP72.

CONCLUSION: Pretreatment with PS has an anti-inflammatory effect on CCK octapeptide-induced AP.

Different profile of cytokine synthesis according to the severity of acute pancreatitis

AIM: To evaluate the cellular synthetic ability of cytokines involved in pro- and anti-inflammatory reactions in patients with AP.

METHODS: Sixty-seven patients with AP (16 severe, 51 mild) and 10 controls were included in the study. Cultures of whole blood were performed in samples obtained within the first 72 h from the onset of pain. Serum levels of interleukins (IL) 6, 8, 10, and TNF-α were measured at baseline and in the supernatant of cultures with (functional reserve) or without stimulation with phytohemaglutinin.

RESULTS: Basal levels of cytokines were significantly higher in patients with severe AP. A significant increase of all pro-inflammatory cytokines vs basal levels was observed in the supernatant after 24 h of whole blood cultures in patients, but not in controls. In contrast, IL-10 increased significantly in the supernatant of cultures only in patients with mild AP. Cells showed a statistically significant functional reserve for all IL in patients with mild, but only for pro-inflammatory cytokines in patients with severe AP.

CONCLUSION: A marked activation of immune system may be observed in patients with AP, being balanced between pro- and anti-inflammatory cytokines in patients with mild but not severe AP. A reduced functional reserve for the synthesis of IL-10 may be observed in patients with severe AP, which might lead to a worst prognosis.

Severity of pancreatitis-associated gut barrier dysfunction is reduced following treatment with the PAF inhibitor lexipafant

The aim of the present study was to investigate the potential effect of treatment with a platelet-activating factor (PAF) antagonist, lexipafant (BB-882), on gut endothelial and epithelial barrier dysfunction and leukocyte recruitment in rats with acute pancreatitis. Severe acute pancreatitis was induced by the intraductal administration of 5% sodium taurodeoxycholate and pancreatitis-associated gut barrier dysfunction was characterized by increased exudation of radiolabelled albumin into the interstitium and alterations in bidirectional (over both the endothelial and epithelial barrier components) permeability of the intestine at the early stage of bile salt-induced acute pancreatitis. Levels of interleukin 1beta and 6, ileal and colonic myeloperoxidase (MPO) content, clearance of radiolabelled albumin from blood to the gut lumen or gut lumen to blood, and leakage of radiolabelled albumin to the ileum or colon were measured 3 and 12h after induction of acute pancreatitis. Treatment with lexipafant 30 min and 6h after pancreatitis reduced severity of pancreatitis-associated intestinal dysfunction, associated with a diminish in systemic concentrations of IL-1 and local leukocyte recruitment. The findings imply that PAF plays a critical role in the development of pancreatitis-associated gut barrier dysfunction and that PAF antagonist in some forms may represent potential candidates for future therapeutic intervention.

Plasmapheresis in the management of acute severe hyperlipidemic pancreatitis: report of 5 cases

BACKGROUND/AIM

Hyperlipidemic pancreatitis is an acute and potentially life-threatening complication of hypertriglyceridemia that can be provoked when triglyceride levels (TGL) exceed 11.3 mmol/l (1,000 mg/dl). Except for standard symptomatic treatment, plasmapheresis has been performed to rapidly reduce TGL and chylomicron levels in the blood. In 5 patients with hyperlipidemic pancreatitis, treatment with plasmapheresis was evaluated.

METHODS

Five male patients who suffered from acute pancreatitis with severe primary hyperlipidemia were studied. In addition to the standard treatment, they were treated with plasmapheresis.

RESULTS

Plasma exchange lowered the lipid level and TGLs in all cases. It also improved abdominal pain, the clinical state of the patients, and signs and symptoms of the disease. Complications of treatment were not encountered, none of the patients died and only 1 patient underwent surgery. Follow-up of the patients lasted 4-28 months, and recurrence of pancreatitis was not noted.

CONCLUSION

Our study showed that plasmapheresis was successfully applied in patients with hyperlipidemic pancreatitis, especially to improve the acute phase of the disease.

Influence of molecule CD 11b blockade on the course of acute ceruleine pancreatitis in rats

Polymorphonuclear cells (PMN) activation is an essential step in acute pancreatitis (AP). We investigated the activation status of PMN, oxidative stress and pancreatic damage in early stage of experimental ceruleine pancreatitis in rats. The PMN action was modulated by monoclonal antibody CD 11b administration. The circulating WBC and polymorphonuclear cells count was reduced after AP induction. Chemiluminescence of whole blood PMN was remarkably reduced in AP group and increased after MoAb CD 11b administration. The CD 11b blockade significantly reduced the WBC infiltration and malondialdehyde (MDA) concentration within pancreatic gland. These data suggest that activated PMN are an important factor in early AP pathogenesis. Neutrophil aggregation within pancreatic gland modulated by monoclonal antibody CD11b contribute to the extent of injury during the early stage of ceruleine experimental pancreatitis in rats.

5-lipoxygenase knockout mice exhibit a resistance to acute pancreatitis induced by cerulein

Here we compare the degree of pancreatitis caused by cerulein in mice lacking 5-lipoxygenase (5-LO) and in the corresponding wild-type mice. Intraperitoneal injection of cerulein in mice resulted in severe, acute pancreatitis characterized by oedema, neutrophil infiltration and necrosis and elevated serum levels of amylase and lipase. Infiltration of pancreatic and lung tissue with neutrophils (measured as increase in myeloperoxidase activity) was associated with enhanced lipid peroxidation (increased tissue levels of malondialdehyde). Immunohistochemical examination demonstrated a marked increase in immunoreactivity for intracellular adhesion molecule-1 (ICAM-1), P-selectin and E-selectin in the pancreas and lung of cerulein-treated mice. In contrast, the degree of (1) pancreatic inflammation and tissue injury (histological score), (2) up-regulation/expression of P-selectin, E-selectin and ICAM-1, and (3) neutrophil infiltration was markedly reduced in pancreatic and lung tissue obtained from cerulein-treated 5-LO-deficient mice. These findings support the view that 5-LO plays an important, pro-inflammatory role in the acute pancreatitis caused by cerulein in mice.

Expression of proteinase-activated receptor 2 during taurocholate-induced acute pancreatic lesion development in Wistar rats

BACKGROUND

Proteinase-activated receptor 2 (PAR-2) is a G-protein coupled transmembrane receptor activated by trypsin by site-specific cleavage. Its presence on pancreatic structures was demonstrated in the past. PAR-2 physiologically involves in duct/acinary cells secretion, arterial tonus regulation or capillary liquid turnover. During development of acute pancreatitis/acute pancreatic lesion (APL) these mentioned structures are influenced by very high concentration of trypsin due to its increased basolateral secretion into the interstitium. The aim of our study as presented was to investigate whether PAR-2 is also involved in APL following changes of PAR-2 expression.

METHODS

APL was investigated in Wistar rats after injection of 0.1 mL taurocholate into the ductus choledochus. Anatomy, histology, reverse transcriptase polymerase chain reaction (RT PCR) as well as immunohistochemistry and Western-blot analysis of pancreatic tissue were performed using antibody mapping of the new NH2 terminal of PAR-2 after trypsin cleavage. Results from control rats and d 1 or d 4 rats after taurocholate injection were compared.

RESULTS

Much higher positivity on acinary/duct cells was observed in APL induced animals than in controls. Similar findings were noticed on arterial smooth muscle cells. Surprisingly, parallel to the exocrine pancreas and vessel findings, enhanced Langerhans' islet cell positivity was observed in experimental animals.

CONCLUSIONS

Based on these results, we have demonstrated that during APL development PAR-2 expression increases. This effect is caused by conformational changes after PAR-2 activation, and the new NH2 terminal of activated receptor presentation. We suggest that PAR-2 physiological functions are enhanced during APL development.

Expression of proteinase-activated receptor 2 during taurocholate-induced acute pancreatic lesion development in Wistar rats

BACKGROUND

Proteinase-activated receptor 2 (PAR-2) is a G-protein coupled transmembrane receptor activated by trypsin by site-specific cleavage. Its presence on pancreatic structures was demonstrated in the past. PAR-2 physiologically involves in duct/acinary cells secretion, arterial tonus regulation or capillary liquid turnover. During development of acute pancreatitis/acute pancreatic lesion (APL) these mentioned structures are influenced by very high concentration of trypsin due to its increased basolateral secretion into the interstitium. The aim of our study as presented was to investigate whether PAR-2 is also involved in APL following changes of PAR-2 expression.

METHODS

APL was investigated in Wistar rats after injection of 0.1 mL taurocholate into the ductus choledochus. Anatomy, histology, reverse transcriptase polymerase chain reaction (RT PCR) as well as immunohistochemistry and Western-blot analysis of pancreatic tissue were performed using antibody mapping of the new NH2 terminal of PAR-2 after trypsin cleavage. Results from control rats and d 1 or d 4 rats after taurocholate injection were compared.

RESULTS

Much higher positivity on acinary/duct cells was observed in APL induced animals than in controls. Similar findings were noticed on arterial smooth muscle cells. Surprisingly, parallel to the exocrine pancreas and vessel findings, enhanced Langerhans' islet cell positivity was observed in experimental animals.

CONCLUSIONS

Based on these results, we have demonstrated that during APL development PAR-2 expression increases. This effect is caused by conformational changes after PAR-2 activation, and the new NH2 terminal of activated receptor presentation. We suggest that PAR-2 physiological functions are enhanced during APL development.

Hereditary, familial, and idiopathic chronic pancreatitis are not associated with polymorphisms in the tumor necrosis factor alpha (TNF-alpha) promoter region or the TNF receptor 1 (TNFR1) gene

PURPOSE

Genetic alterations that are associated with acute and chronic pancreatitis remain to be identified.

METHODS

The authors investigated two functionally active tumor necrosis factor (TNF) promoter region polymorphisms at positions -238 and -308 and the entire coding region of the corresponding TNF receptor 1 (TNFR1) gene in 54 patients with hereditary, familial, and idiopathic chronic pancreatitis who were previously tested negative for cationic trypsinogen mutations by direct DNA sequencing.

RESULTS

In three patients, we detected novel DNA variants in the TNFR1 gene that did not segregate with the disease. The genotype frequencies of the TNF promoter polymorphisms were similar between patients and controls.

CONCLUSION

These polymorphisms are not associated with hereditary, familial, or idiopathic chronic pancreatitis.

Plasma exchange for hypertriglyceridemic acute necrotizing pancreatitis: report of two cases

We report two cases of hypertriglyceridemic necrotizing pancreatitis treated by plasma exchange (PE). The outcome of each case was quite different according to the timing of PE. A 36 year old man presented with abdominal pain, and a diagnosis of severe acute pancreatitis was made. His serum triglyceride (TG) level was 6,460 mg/dl. He did not undergo PE at first, however, his condition never improved and PE was performed 20 days after the onset of his illness. Finally, he died of multiple organ failure and sepsis. In contrast, a 52 year old man with acute necrotizing pancreatitis was referred to our department. He received PE quickly after hospital admission. His serum TG level, which was 3,540 mg/dl at hospital admission, dramatically returned to normal limits, and he was discharged from the hospital 62 days after admission. The prognosis of severe necrotizing pancreatitis due to hypertriglyceridemia is extremely poor. PE should be applied for the treatment of hypertriglyceridemic necrotizing pancreatitis immediately after its onset.

Leptin protects the pancreas from damage induced by caerulein overstimulation by modulating cytokine production

BACKGROUND

Recent identification of specific leptin receptors in the pancreas suggests that this peptide may also play some role in this gland.

AIM

To examine the effect of intraperitoneal (i.p.) or intracerebroventricular (i.c.v.) administration of leptin in rats on caerulein-induced pancreatitis (CIP), pancreatic gene expression of leptin and inflammatory cytokine production.

METHODS

Caerulein (25 micrograms/kg) was infused subcutaneously into conscious rats over 5 h to produce CIP. Leptin (1, 5, or 10 micrograms/kg) was injected i.p. or i.c.v. 30 min prior to the CIP induction. The plasma level of TNF alpha and IL-4 was determined by ELISA, while plasma leptin was measured by RIA and leptin gene expression in pancreas by RT-PCR.

RESULTS

CIP was characterized by the usual pancreatic edema, reduction in pancreatic blood flow (PBF) and an increase in serum levels of amylase, TNF alpha and IL-4. Pretreatment with i.p. or i.c.v. leptin of the CIP rats partially reversed the harmful effects of CIP on the pancreas, and reduced pancreatic inflammation and the fall in PBF. This was accompanied by a dose-dependent reduction in serum levels of amylase and TNF alpha, while serum IL-4 in the CIP rats pretreated with leptin rose dose-dependently as compared to control rats with CIP alone. Pretreatment with leptin resulted in the dose-dependent rise in plasma leptin level over that observed in vehicle-treated controls. Leptin mRNA expression in the pancreas was dose-dependently increased after infusion of caerulein. Leptin content in isolated pancreatic acini was also increased dose-dependently by caerulein added to the incubation medium bathing these acini.

CONCLUSIONS

(1) Exogenous leptin protects the pancreas against damage by CIP; (2) endogenous leptin seems to limit the extend of pancreatic damage, and (3) these protective effects of leptin could be attributed to the reduction in TNF alpha and to the increase in IL-4 production.

Absence of endogenous interleukin-6 enhances the inflammatory response during acute pancreatitis induced by cerulein in mice

Interleukin-6 (IL-6) exerts a wide spectrum of regulatory activities during immune and inflammatory responses. The aim of this study was to investigate the role of endogenous IL-6 in the inflammatory response associated with acute pancreatitis. Acute pancreatitis was induced by hourly (x5) i.p. injections of cerulein (50 microg/kg, suspended in saline solution) in IL-6 deficient mice (IL-6-KO) and wild-type (IL-6WT) littermates. IL-6KO mice exhibited a more severe tissue injury and a higher rate of mortality and when compared to IL-6WT mice. Acute pancreatitis was characterized by edema, neutrophil infiltration, tissue hemorrhage and cell necrosis, upregulation of P-selectin and intercellular adhesion molecule-1 (ICAM-1), as well as increases in the serum levels of amylase and lipase. The degree of oxidative and nitrosative tissue damage was significantly greater in IL-6KO mice than in wild-type littermates, as indicated by higher tissue levels of malondialdehyde and nitrosylated proteins. Plasma levels of the inflammatory cytokines tumour necrosis factor-alpha and interleukin-1beta were also greatly enhanced in IL-6KO mice when compared to wild-type mice. These events were correlated with an increase in the staining (immunoreactivity) for poly (ADP-ribose) polymerase (PARP) in the pancreas of cerulein-treated IL-6WT. The staining for PARP was more pronounced in IL-6KO mice subjected to acute pancreatitis than in the corresponding WT mice. These data demonstrate that endogenous IL-6 exerts an anti-inflammatory role during acute pancreatitis, possibly by regulating the expression of adhesion molecules, the subsequent adhesion and activation of neutrophils and finally the generation of cytokine and reactive oxygen or nitrogen species.

Inducible nitric oxide synthase-deficient mice exhibit resistance to the acute pancreatitis induced by cerulein

Oxidative stress plays an important role in the early stage of acute pancreatitis as well as the associated multiple organ injury. Here we compare the degree of pancreatitis caused by cerulein in mice lacking the inducible (or type 2) nitric oxide synthase (iNOS) and in the corresponding wild-type mice. Intraperitoneal injection of cerulein resulted in wild-type mice in a severe, acute pancreatitis, which was characterized by edema, neutrophil infiltration, tissue hemorrhage and cell necrosis as well as increases in the serum levels of amylase and/or lipase. The infiltration of the pancreatic tissue of these animals with neutrophils (measured as increase in myeloperoxidase activity) was associated with up-regulation/expression of the adhesion molecules ICAM-1 and P-selectin as well as signs of enhanced lipid peroxidation (e.g., increased tissue levels of malondialdehyde). Immunohistochemical examination demonstrated a marked increase in the staining (immunoreactivity) for nitrotyrosine and poly (ADP-ribose) synthetase (PARS) in the pancreas of cerulein-treated iNOS wild-type mice. In contrast, the degree of pancreatic inflammation and tissue injury (histological score), upregulation/expression of P-selectin and ICAM-1, the staining for nitrotyrosine and PARS, and lipid peroxidation was markedly reduced in pancreatic tissue sections obtained from cerulein-treated iNOS-deficient mice. These findings support the view that iNOS plays an important, pro-inflammatory role in the acute pancreatitis caused by cerulein in mice.

New laboratory tests in acute pancreatitis

Acute pancreatitis (AP) is a common disease with wide variation of severity. The diagnosis of AP is usually based on high serum amylase or lipase values but the accuracy of these methods is considered unsatisfactory. One in five of the patients develops a severe disease and carries a considerable risk of development of organ failure and high mortality. Early detection of patients with severe AP and especially those with increased risk of organ failure is importance since such patients seem to benefit from treatment in an intensive care unit started as soon as possible after presentation. In addition to enzymological methods, increasing interest has been focused on laboratory markers reflecting the level of inflammatory response in AP. At present, in routine clinical work the most commonly used severity marker is serum C-reactive protein, the concentration of which rises too slowly to be used for early prediction of severity. New therapies aiming at modifying the course of systemic inflammation in AP are being developed and therefore monitoring the patient's immune inflammatory status is needed. In this review article we present the current knowledge of laboratory tests, which has been evaluated for diagnostic and prognostic purposes in AP.

Soluble receptors released during acute pancreatitis interfere with the detection of tumor necrosis factor-alpha

OBJECTIVE

To evaluate the interfering effect of tumor necrosis factor-alpha soluble receptor when measuring circulating concentrations of tumor necrosis factor-alpha in an experimental model of acute pancreatitis.

DESIGN

Randomized, controlled trial.

SETTING

Experimental laboratory.

SUBJECTS

Male Wistar rats.

INTERVENTIONS

Acute pancreatitis was induced by intraductal administration of 5% sodium taurocholate. Saline was administered in a control group. Serums were overloaded with known amounts of tumor necrosis factor-alpha or macrophage inflammatory protein-2.

MEASUREMENTS AND MAIN RESULTS

Three hours after induction, serum concentrations of free tumor necrosis factor-alpha, total tumor necrosis factor-alpha, and soluble receptor of tumor necrosis factor-alpha were measured. No detectable concentrations of free tumor necrosis factor-alpha were found in any experimental group. By contrast, significant increases in total tumor necrosis factor-alpha and soluble receptor of tumor necrosis factor-alpha were found after induction of pancreatitis. Overloading of serum with tumor necrosis factor-alpha resulted in detection of 50% of the expected concentrations of free tumor necrosis factor-alpha from control animals and only of 5% from the pancreatitis group. Overloading the serum with macrophage inflammatory protein-2 resulted in a detection of 100% of the expected concentrations in both control and treated animals.

CONCLUSION

Circulating soluble receptor of tumor necrosis factor-alpha could interfere with the detection of tumor necrosis factor-alpha in some pathologies, such as pancreatitis, that are associated with increases in soluble receptor of tumor necrosis factor-alpha.

Investigation of the interleukin 1 gene cluster and its association with acute pancreatitis

The interleukin 1 (IL-1) gene cluster has been implicated in acute pancreatitis. Penta-allelic and bi-allelic polymorphisms exist in the IL-1RN and IL-1B genes, respectively. The aim of the study was to investigate these polymorphisms in acute pancreatitis. Genotype and allele frequencies were determined in patients (n = 116) and healthy controls (n = 170) using the polymerase chain reaction. PCR products from the IL-1B study were further digested with Taq I restriction endonuclease. Patients were categorised according to aetiology, severity, and organ-failure scores. Allele 1 of the IL-1RN polymorphism was significantly increased in patients compared with controls (72.0 vs. 63.0%; p = 0.029, Pc = 0.029), in severe cases compared with controls (81.9 vs. 63.0%; p = 0.002, Pc = 0.004), in idiopathics compared with controls (82.4 vs. 63.0%; p = 0.002, Pc = 0.006), and in severe cases compared with mild cases (81.9 vs. 67.5%; p = 0.023, Pc = 0.046). Allele 2 was significantly decreased in severe cases compared with controls (18.1 vs. 33.0%; p = 0.013, Pc = 0.026), in idiopathics compared with controls (17.6 vs. 33%; p = 0.013, Pc = 0.039), and in severe cases compared with mild cases (18.1 vs. 32.5%; p = 0.023, Pc = 0.046). No significant differences were found for the Taq I allele or genotype frequencies between controls and patients/subgroups of patients. IL-1RN appears to determine severity of acute pancreatitis and susceptibility to idiopathic acute pancreatitis. No association was found between IL-1B and the disease.

Inflammatory mediators in acute pancreatitis

Inflammatory mediators play a key role in acute pancreatitis and the resultant multiple organ dysfunction syndrome, which is the primary cause of death in this condition. Recent studies have confirmed the critical role played by inflammatory mediators such as TNF-alpha, IL-1beta, IL-6, IL-8, PAF, IL-10, C5a, ICAM-1, and substance P. The systemic effects of acute pancreatitis have many similarities to those of other conditions such as septicaemia, severe burns, and trauma. The delay between the onset of inflammation in the pancreas and the development of the systemic response makes acute pancreatitis an ideal experimental and clinical model with which to study the role of inflammatory mediators and to test novel therapies. Elucidation of the key mediators involved in the pathogenesis of acute pancreatitis will facilitate the development of clinically effective anti-inflammatory therapy.

N-acetylcysteine decreases severity of acute pancreatitis in mice

Oxidative stress plays a major role in the early stage of acute pancreatitis. This study assessed the effects of N-acetylcysteine (NAC), a reduced glutathione (GSH) provider and a direct scavenger of reactive oxygen intermediates, in the course of acute pancreatitis in mice. Acute pancreatitis (AP) was induced by intraperitoneal (i.p.) injections of cerulein. Mice received NAC (1,000 mg/kg, i.p.) every 3 h, starting either 1 h before the first cerulein injection (prophylactic group) or 1 h after the first cerulein injection (therapeutic group), or i.p. saline injections for controls. Severity of AP was evaluated by histology, serum hydrolase levels, and serum and intrapancreatic levels of MCP-1 and interleukin 6 (IL-6). Pancreatic conjugated dienes and intrapancreatic and intrahepatic GSH levels were measured to assess the local and systemic oxidative processes. Acute pancreatitis was also induced with a CDE diet in controls and mice receiving either both NAC ad libidum in drinking water and 1,000 mg/kg i.p. injection once daily. The severity of pulmonary lesions was assessed by arterial blood gases (pO2) and intrapulmonary myeloperoxidase (MPO content) measurements as well as the survival of mice. The severity of cerulein-induced AP was significantly decreased in the prophylactic group compared with the therapeutic and control groups. Prophylactic administration of NAC also decreased the intrapancreatic levels of conjugated dienes compared with controls. The intrapancreatic and systemic release of MCP- 1 and IL-6 was also decreased in the prophylactic group 3 and 6 hours after AP induction. In addition, NAC pretreatment also reduced hepatic IL-6 production at 3 and 6 hours after starting cerulein challenge. In CDE-induced AP, the severity of lung injury (hypoxemia, MPO content) was decreased, and survival was improved by NAC. NAC administered in a prophylactic protocol limits the severity of experimental acute pancreatitis in mice, as well as its systemic complications and related mortality.

Inflammatory mediators in acute pancreatitis

Inflammatory mediators play a key role in acute pancreatitis and the resultant multiple organ dysfunction syndrome, which is the primary cause of death in this condition. Recent studies have confirmed the critical role played by inflammatory mediators such as TNF-alpha, IL-1beta, IL-6, IL-8, PAF, IL-10, C5a, ICAM-1, and substance P. The systemic effects of acute pancreatitis have many similarities to those of other conditions such as septicaemia, severe burns, and trauma. The delay between the onset of inflammation in the pancreas and the development of the systemic response makes acute pancreatitis an ideal experimental and clinical model with which to study the role of inflammatory mediators and to test novel therapies. Elucidation of the key mediators involved in the pathogenesis of acute pancreatitis will facilitate the development of clinically effective anti-inflammatory therapy.

Anti-inflammatory cytokine response and clinical outcome in acute pancreatitis

OBJECTIVE

To test the hypothesis that elevated interleukin (IL)-10 plasma concentration relative to IL-6 and IL-8 in patients with acute pancreatitis is associated with improved clinical outcome.

DESIGN

Case series.

SETTING

University hospital surgical and intensive care unit.

PATIENTS

Patients with mild (n = 18) and severe (n = 14) acute pancreatitis were recruited within 12 hrs of admission and studied for 5 days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The plasma concentration of IL-10 was significantly elevated in patients with severe pancreatitis during the 5 days and especially so in those who died compared with survivors on day 5 (p <.03). The ratio of IL-10/IL-6 was decreased in patients with severe pancreatitis on day 5 (p < .01). There was a significant decrease in the ratio of IL-10/IL-8, but not of IL-10/IL-6, during the first 5 days (p < .014).

CONCLUSIONS

The findings are consistent with the hypothesis that an increase in plasma IL-10 relative to IL-6 or IL-8 is associated with improved clinical outcome.

Effect of diaspirin cross-linked hemoglobin on normal and postischemic microcirculation of the rat pancreas

Microcirculatory alterations with reduced nutritive supply to the pancreas could be the cause of hyperamylasemia, which occurs in some patients receiving the vasoactive oxygen carrier diaspirin cross-linked hemoglobin (DCLHb) in clinical studies. Therefore, the effects of DCLHb on rat pancreas microcirculation were evaluated. Anesthetized Sprague-Dawley rats received one of the following treatments during baseline conditions (n = 7 rats/group): 10% hydroxyethyl starch (HAES) (0.4 ml/kg), DCLHb (400 mg/kg), or DCLHb (1,400 mg/kg). After 1 h of complete, reversible pancreatic ischemia, other animals received 10% HAES (0.4 ml/kg) or DCLHb (400 mg/kg) during the onset of reperfusion. The number of red blood cell-perfused capillaries (functional capillary density, FCD) and the level of leukocyte adherence in postcapillary venules in the pancreas were assessed by means of intravital microscopy during 2 h after treatment. In the nonischemic groups, FCD was 18% greater after DCLHb (1,400 mg/kg) than after 10% HAES treatment without any increase in leukocyte adherence. In the inschemia-reperfusion (I/R) 10% HAES group, FCD was significantly (P < 0.05) lowered, leukocyte adherence enhanced, and mean arterial pressure (MAP) reduced by 31% compared with nonischemic animals. DCLHb treatment in the I/R group resulted in a slight increase in FCD, a significant (P < 0.05) reduction of leukocyte adherence, and a complete restoration of MAP compared with the animals of the I/R control group. Thus our data provide no evidence for a detrimental effect on the pancreatic microcirculation or an enhanced risk of postischemic pancreatitis by DCLHb.

Therapy for microcirculatory disorders in severe acute pancreatitis: effectiveness of platelet-activating factor receptor blockade vs. endothelin receptor blockade

Many of the complications of severe acute pancreatitis are the result of the amplifying effects of microcirculatory disruption. The factors causing microcirculatory disorders in acute pancreatitis involve vasoactive mediators such as platelet-activating factor (PAF) and endothelin-1 (ET) activated during the inflammatory response to pancreatic injury. To further evaluate the potential therapeutic role of specific receptor antagonists (RA) to these mediators, the present study compares the effect of PAF and ET receptor blockade on microcirculation and organ function in a well-established rodent model of severe acute pancreatitis. Six hours after acute pancreatitis induction, rats were randomized to therapy with ET-RA (50 mg/kg LU-135252), PAF-RA (82 microg/kg WEB-2170), or NaCl 0.9% (volume equivalent). After 18 hours of fluid resuscitation, animals were relaparotomized for intravital microscopic determination of capillary blood flow, leukocyte rolling, and capillary permeability in the pancreas and colon. Other measurements included cardiorespiratory parameters, hematocrit, pleural effusions, ascites, urine production, and survival. Compared to saline treatment both ET-RA and PAF-RA significantly improved capillary blood flow in the pancreas and colon, reduced leukocyte rolling, and stabilized capillary permeability. The beneficial effects of receptor antagonist treatment on microcirculation were associated with decreased fluid loss into the third space, improved renal and respiratory function, and survival. Although both receptor antagonists likewise improved capillary blood flow, ET-RA was significantly more effective in counteracting leukocyte rolling and capillary leakage, thereby further reducing fluid sequestration. The present study confirms the beneficial effects of PAf and ET receptor blockade on microcirculation inside and outside the pancreas, organ function, and survival when given at the early stage of severe pancreatitis. Because ET-RA was more effective in stabilizing capillary permeability and avoiding subsequent fluid loss into the third space, we propose that ET-RA should be tested in a clinical trial (either in comparison or in addition to PAF-RA).

Inhibition of platelet-activating factor, intercellular adhesion molecule 1 and platelet endothelial cell adhesion molecule 1 reduces experimental pancreatitis-associated gut endothelial barrier dysfunction

BACKGROUND

Endothelial barrier dysfunction is a critical link in the development of tissue injury and organ dysfunction, via upregulation and exposure of adhesion molecules, intercellular signals and leucocyte-endothelial cell interactions. Inhibitors of inflammatory mediators and receptors have been suggested as a means of downregulating the cascade of both local and systemic inflammation.

METHODS

The potential therapeutic inhibition of platelet-activating factor (PAF), intercellular adhesion molecule (ICAM) 1 and platelet endothelial cell adhesion molecule (PECAM) 1 was investigated in pancreatitis-associated gut endothelial dysfunction in rats, by treatment with a PAF antagonist (lexipafant, BB-882) and monoclonal antibodies against rat ICAM-1 (anti-ICAM1-Mb) and PECAM (anti-PECAMA1-Mb). Alterations in gut endothelial barrier dysfunction and leucocyte recruitment, and systemic levels of interleukins were evaluated.

RESULTS

Plasma exudation measured by the albumin leakage index and tissue leucocyte recruitment in the distal small intestine and colon increased significantly 12 h after induction of pancreatitis and treatment with saline. These alterations were to varying degrees counteracted by treatment with lexipafant, anti-ICAM1-Mb or anti-PECAM1-Mb. Alterations in levels of interleukin (IL) 1 paralleled the changes in gut endothelial barrier dysfunction and leucocyte trapping.

CONCLUSION

Treatment with lexipafant and monoclonal antibodies against ICAM-1 or PECAM-1 reduced the severity of pancreatitis-associated gut endothelial dysfunction, and decreased systemic concentrations of IL-1 and local leucocyte recruitment.

Blood concentrations of polymorphonuclear leucocyte elastase and interleukin-6 are indicators for the occurrence of multiple organ failures at the early stage of acute pancreatitis

We studied potential indicators of severe acute pancreatitis by measuring the blood concentrations of various cytokines, polymorphonuclear leucocyte elastase (PMN-E), acute phase reactants, pancreatic amylase (P-AMY), pancreatic elastase-1 (E-1) and white blood cell (WBC) counts in patients with acute pancreatitis. In addition, the presence of multiple organ damage was assessed. Subjects consisted of 22 patients with acute pancreatitis including severe (n = 11), moderate (n = 4) and mild (n = 7) cases. A significant positive correlation was observed between the number of organs damaged and the peak concentrations of interleukin (IL)-6, PMN-E, C-reactive protein (CRP) and pancreatic secretory trypsin inhibitor (PSTI). Among these markers, blood concentrations of PMN-E and IL-6 rapidly increased and peaked at the early phase of acute pancreatitis whereas CRP and PSTI did not. The elevation of PMN-E and IL-6 was greater the more severe the symptoms. However, no significant correlation was observed between the number of organs damaged and the maximum serum concentrations of P-AMY and E-1, or the WBC count, which have been considered to be markers of pancreatitis. These results suggest that PMN-E and IL-6 concentrations are useful indicators of severity and prognosis and their determination facilitates the selection of appropriate treatment in the early stages of disease to prevent the aggressive progression of acute pancreatitis.

Sodium fusidate and the cytokine response in an experimental model of acute pancreatitis

BACKGROUND

New therapies designed to downregulate the aberrant immune response associated with severe acute necrotizing pancreatitis (ANP) are being increasingly investigated in different experimental models of ANP. The aim of this study was to test the potential effects of sodium fusidate on the course of severe ANP in rabbits.

METHODS

ANP was induced in 20 rabbits by retrograde injection of 5 per cent chenodeoxycholic acid into the pancreatic duct followed by duct ligation. The rabbits were allocated to pretreatment with intravenous physiological saline or sodium fusidate 80 mg/kg 30 min before the induction of ANP. Levels of serum amylase, lipase, tumour necrosis factor (TNF) alpha, interleukin (IL) 8, glucose and calcium, and leucocyte count were measured every 3 h for a total of 12 h. At the end of the experiment, ascitic fluid was collected and the pancreatic, lung and kidney tissues were obtained for histological examination.

RESULTS

Pretreatment with sodium fusidate reduced the mortality rate from six of ten to three of ten (P < 005) and reduced the output of ascitic fluid from 5 2 to 2.0 ml/h (P < 0001). Serum levels of TNF-alpha and IL-8 were reduced significantly in the treated group from 5 min up to 9 h after induction of ANP. The leucopenia observed after 3 h in the untreated group was not significantly improved in the group treated with sodium fusidate (P = 0.055). By contrast, both treated and untreated rabbits had similar biochemical changes including levels of amylase, lipase, glucose and calcium as well as similar histological changes in the pancreas and lungs.

CONCLUSION

Pretreatment with sodium fusidate resulted in a considerable reduction in mortality rate and ascitic fluid output in rabbits with bile-induced ANP, probably by lowering the TNF-alpha and IL-8 blood levels. However, pretreatment with sodium fusidate did not alter the local or systemic manifestations of ANP. Thus, cytokines other than TNF-alpha and IL-8 are likely to mediate the local and systemic symptoms of ANP.

Role of substance P and the neurokinin 1 receptor in acute pancreatitis and pancreatitis-associated lung injury

Substance P, acting via the neurokinin 1 receptor (NK1R), plays an important role in mediating a variety of inflammatory processes. However, its role in acute pancreatitis has not been previously described. We have found that, in normal mice, substance P levels in the pancreas and pancreatic acinar cell expression of NK1R are both increased during secretagogue-induced experimental pancreatitis. To evaluate the role of substance P, pancreatitis was induced in mice that genetically lack NK1R by administration of 12 hourly injections of a supramaximally stimulating dose of the secretagogue caerulein. During pancreatitis, the magnitude of hyperamylasemia, hyperlipasemia, neutrophil sequestration in the pancreas, and pancreatic acinar cell necrosis were significantly reduced in NK1R-/- mice when compared with wild-type NK1R+/+ animals. Similarly, pancreatitis-associated lung injury, as characterized by intrapulmonary sequestration of neutrophils and increased pulmonary microvascular permeability, was reduced in NK1R-/- animals. These effects of NK1R deletion indicate that substance P, acting via NK1R, plays an important proinflammatory role in regulating the severity of acute pancreatitis and pancreatitis-associated lung injury.