Role of serum endotoxin and antiendotoxin core antibody levels in predicting the development of multiple organ failure in acute pancreatitis

Fire in the belly: A scoping review of the immunopathological mechanisms of acute pancreatitis

Introduction

Acute pancreatitis (AP) is characterised by an inflammatory response that in its most severe form can cause a systemic dysregulated immune response and progression to acute multi-organ dysfunction. The pathobiology of the disease is unclear and as a result no targeted, disease-modifying therapies exist. We performed a scoping review of data pertaining to the human immunology of AP to summarise the current field and to identify future research opportunities.

Methods

A scoping review of all clinical studies of AP immunology was performed across multiple databases. Studies were included if they were human studies of AP with an immunological outcome or intervention.

Results

205 studies met the inclusion criteria for the review. Severe AP is characterised by significant immune dysregulation compared to the milder form of the disease. Broadly, this immune dysfunction was categorised into: innate immune responses (including profound release of damage-associated molecular patterns and heightened activity of pattern recognition receptors), cytokine profile dysregulation (particularly IL-1, 6, 10 and TNF-α), lymphocyte abnormalities, paradoxical immunosuppression (including HLA-DR suppression and increased co-inhibitory molecule expression), and failure of the intestinal barrier function. Studies including interventions were also included. Several limitations in the existing literature have been identified; consolidation and consistency across studies is required if progress is to be made in our understanding of this disease.

Conclusions

AP, particularly the more severe spectrum of the disease, is characterised by a multifaceted immune response that drives tissue injury and contributes to the associated morbidity and mortality. Significant work is required to develop our understanding of the immunopathology of this disease if disease-modifying therapies are to be established.

Liver injury associated with acute pancreatitis: The current status of clinical evaluation and involved mechanisms

Acute pancreatitis (AP) is a very common acute disease, and the mortality rate of severe AP (SAP) is between 15% and 35%. The main causes of death are multiple organ dysfunction syndrome and infections. The mortality rate of patients with SAP related to liver failure is as high as 83%, and approximately 5% of the SAP patients have fulminant liver failure. Liver function is closely related to the progression and prognosis of AP. In this review, we aim to elaborate on the clinical manifestations and mechanism of liver injury in patients with AP.

Sampling Thoracic Duct Lymph After Esophagectomy: A Pilot Study Investigating the "Gut-Lymph" Concept

Introduction: Gut-lymph in animal models of acute disease is altered by intestinal ischemia and contributes to the development of systemic inflammation and organ dysfunction. Investigating gut-lymph in humans is hampered difficulty in accessing the thoracic duct (TD) for lymph sampling. The aims of this study were to develop and pilot a technique of intraoperative TD cannulation with delayed embolization to serially measure TD lymph pressure, flow, and composition (including markers of intestinal injury) during the early postoperative period and in response to enteral feeding and vasopressor treatment. Methods: A Seldinger technique was used for percutaneous TD cannulation during an Ivor Lewis esophagogastrectomy. Lymph flow rate and pressure were measured. TD lymph and plasma were sampled at 12 hourly intervals for up to 120 hours after surgery and before TD embolization. Biochemistry, lipids, cytokines, and markers of intestinal injury were measured before and after enteral feeding commenced at 36 hours. Results: Intraoperative TD cannulation was technically feasible in three of four patients. Delayed TD embolization was only successful in one of three patients, with two patients requiring a re-thoracotomy to treat chylothorax. Profound changes in TD composition, but not flow rate, occurred over time and in response to enteral feeding and vasopressors. TD lymph compared with plasma had significantly higher lipase (1.4-17 × ), interleukin-6 (8-108 × ), tumor necrosis factor-α (2.7-17 × ), d-lactate (0.3-23 × ), endotoxin (0.1-41 × ), and intestinal fatty acid binding protein (1.1-853 × ). Conclusions: Although TD cannulation and lymph sampling were successful, TD embolization failed in two of three patients. The composition of sampled TD lymph changed dramatically in response to enteral feeding, indicating intestinal ischemia that could be exacerbated by nonselective vasopressors. The higher concentration of proinflammatory cytokines and gut injury markers in TD lymph, compared with plasma, lends support to the gut-lymph concept.

Comprehensive Mechanism, Novel Markers and Multidisciplinary Treatment of Severe Acute Pancreatitis-Associated Cardiac Injury - A Narrative Review

Acute pancreatitis (AP) is one of the common acute abdominal inflammatory diseases in clinic with acute onset and rapid progress. About 20% of the patients will eventually develop into severe acute pancreatitis (SAP) characterized by a large number of inflammatory cells infiltration, gland flocculus flaky necrosis and hemorrhage, finally inducing systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). Pancreatic enzyme activation, intestinal endotoxemia (IETM), cytokine activation, microcirculation disturbance, autonomic nerve dysfunction and autophagy dysregulation all play an essential role in the occurrence and progression of SAP. Organ dysfunction is the main cause of early death in SAP. Acute kidney injury (AKI) and acute lung injury (ALI) are common, while cardiac injury (CI) is not, but the case fatality risk is high. Many basic studies have observed obvious ultrastructure change of heart in SAP, including myocardial edema, cardiac hypertrophy, myocardial interstitial collagen deposition. Moreover, in clinical practice, patients with SAP often presented various abnormal electrocardiogram (ECG) and cardiac function. Cases complicated with acute myocardial infarction and pericardial tamponade have also been reported and even result in stress cardiomyopathy. Due to the molecular mechanisms underlying SAP-associated cardiac injury (SACI) remain poorly understood, and there is no complete, unified treatment and sovereign remedy at present, this article reviews reports referring to the pathogenesis, potential markers and treatment methods of SACI in recent years, in order to improve the understanding of cardiac injury in severe pancreatitis.

Dynamic frailty: Objective physiological assessment to guide management in necrotizing pancreatitis

BACKGROUND

Physical frailty as a measure of physiological reserve is an important yet understudied topic in necrotizing pancreatitis. We measured frailty metrics in patients with necrotizing pancreatitis at baseline and at 1 month to assess dynamic change. We hypothesized that greater baseline frailty and steeper decline in frailty biomarkers are associated with worse outcomes in necrotizing pancreatitis.

METHODS

A retrospective analysis of an institutional, necrotizing pancreatitis-specific database was performed. First order outcomes were organ failure, infected necrosis, step-up approach failure, and mortality. Baseline frailty assessment included measurement of comorbid diseases (modified frailty index), nutritional status (prognostic nutritional index), and radiologic sarcopenia (psoas muscle index, Hounsfield unit average calculation). Dynamic frailty was evaluated using psoas muscle index and Hounsfield unit average calculation. Significant associations between baseline and dynamic frailty with outcomes were analyzed.

RESULTS

Three hundred and forty-one patients were included in this study. Most patients were male (65%) with biliary etiology of necrotizing pancreatitis (46%). Baseline comorbid diseases and baseline sarcopenia were not associated with first order outcomes. Lower baseline prognostic nutritional index was associated with organ failure (P < .001) and infected necrosis (P < .001). After 30 days, 25% of patients became sarcopenic. Larger declines in all sarcopenia metrics were associated with organ failure, infected necrosis, and/or death (P < .05). Lower psoas area and density were independent risk factors for organ failure and infected necrosis.

CONCLUSION

Dynamic changes in sarcopenia-focused frailty metrics were significantly and consistently associated with organ failure, infected necrosis, and death. Further development of a dynamic frailty index to objectively guide decision-making in necrotizing pancreatitis is warranted.

[Acute kidney injury following acute pancreatitis (AP-AKI): Definition, Pathophysiology, Diagnosis and Therapy]

Acute pancreatitis (AP) is the most frequent gastrointestinal cause for hospitalization and one of the leading causes of in-hospital deaths. Severe acute pancreatitis is often associated with multiorgan failure and especially with acute kidney injury (AKI). AKI can develop early or late in the course of the disease and is a strong determinator of outcome. The mortality in the case of dialysis-dependent AKI and acute pancreatitis raises exponentially in the affected patients. AP-induced AKI (AP-AKI) shows many similarities but also distinct differences to other causes of AKI occurring in the intensive care unit setting. The knowledge of the exact pathophysiology can help to adjust, control and improve therapeutic approaches to the disease. Unfortunately, there are only a few studies dealing with AP and AKI.In this review, we discuss recent data about pathogenesis, causes and management of AP-AKI in patients with severe acute pancreatitis and exploit in this regard the diagnostic and prognostic potential of respective newer serum and urine markers.

Association of endotoxaemia & gut permeability with complications of acute pancreatitis: Secondary analysis of data

Background & objectives:

In acute pancreatitis (AP) gut barrier dysfunction is considered as an important predisposing factor leading to increased intestinal permeability (IP). In this study a pooled analysis of data published in our previous four studies on various aspects of gut permeability and endotoxaemia in patients with AP was attempted to find an association between increased IP and severity of disease and associated complications.

Methods:

This study was a pooled analysis of data of four previously published prospective studies on AP. Gut permeability, assessed by lactulose/mannitol excretion in urine and endotoxin core antibodies type IgG and IgM (EndoCab IgG and IgM) were measured on days zero and seven (D0 and D7) of admission. All patients received standard treatment of AP. We studied whether IgG and IgM anti-endotoxin titres and lactulose-mannitol ratio (LMR) at admission and D7 were associated with organ failure, infection and mortality.

Results:

The titres of anti-endotoxin IgG and IgM were lower in all patients of AP (n=204), both in mild AP (n=24) and severe AP (n=180) in the first week, compared to controls (n=15). There was no significant difference in serum IgG and IgM anti-endotoxin levels and LMR at baseline and at D7 among patients with organ failure, infection and mortality.

Interpretation & conclusions:

Our findings showed that serum IgG and IgM anti-endotoxin titres and LMR at admission and at day 7 were not associated with organ failure, infection, and death of patients with AP.

Coordinated Induction of Antimicrobial Response Factors in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by dysregulated autoantibody production and complement activation leading to multi-organ damage. The disease is associated with increased intestinal permeability. In this study, we tested the hypothesis that SLE subjects have increased systemic exposure to bacteria. Since bacteria induce the expression of antimicrobial response factors (ARFs), we measured the levels of a series of clinically relevant ARFs in the plasma of SLE subjects. We found that levels of sCD14, lysozyme, and CXCL16 were significantly elevated in SLE subjects. A strong positive correlation was also observed between sCD14 and SELENA-SLEDAI score. Interestingly, the ratio of EndoCAb IgM:total IgM was significantly decreased in SLE and this ratio was negatively correlated with sCD14 levels. Although, there were no significant differences in the levels of lipopolysaccharide binding protein (LBP) and fatty acid binding protein 2 (FABP2), we observed significant positive correlations between lysozyme levels and sCD14, LBP, and FABP2. Moreover, galectin-3 levels also positively correlate with lysozyme, sCD14, and LBP. Since our SLE cohort comprised 43.33% males, we were able to identify gender-specific changes in the levels of ARFs. Overall, these changes in the levels and relationships between ARFs link microbial exposure and SLE. Approaches to reduce microbial exposure or to improve barrier function may provide therapeutic strategies for SLE patients.

Novel strategies for the treatment of acute pancreatitis based on the determinants of severity

Acute pancreatitis (AP) is a common disease for which a specific treatment remains elusive. The key determinants of the outcome from AP are persistent organ failure and infected pancreatic necrosis. The prevention and treatment of these determinants provides a framework for the development of specific treatment strategies. The gut-lymph concept provides a common mechanism for systemic inflammation and organ dysfunction. Acute and critical illness, including AP, is associated with intestinal ischemia and drastic changes in the composition of gut lymph, which bypasses the liver to drain into the systemic circulation immediately proximal to the major organ systems which fail. The external diversion of gut lymph and the targeting of treatments to counter the toxic elements in gut lymph offers novel approaches to the prevention and treatment of persistent organ failure. Infected pancreatic necrosis is increasingly treated with less invasive techniques, the mainstay of which is drainage, both endoscopic and percutaneous. Further improvements will occur with the strategies to accelerate liquefaction and through a fundamental re-design of drains, both of which will increase drainage efficacy. The determinants of severity and outcome in patients admitted with AP provide the basis for innovative treatment strategies. The priorities are to translate the gut-lymph concept to clinical practice and to improve the design and active use of drains for infected complications of AP.

Chai-Qin-Cheng-Qi Decoction and Carbachol Improve Intestinal Motility by Regulating Protein Kinase C-Mediated Ca2+ Release in Colonic Smooth Muscle Cells in Rats with Acute Necrotising Pancreatitis

Chai-Qin-Cheng-Qi decoction (CQCQD) improves intestinal motility in acute pancreatitis (AP), but the mechanism(s) require elucidation. We investigated the effects of CQCQD and carbachol, a prokinetic agent, on colonic smooth muscle cells (SMCs) in L-arginine-induced necrotising AP model in rats. In treatment groups, intragastric CQCQD (20 g/kg, 2 hourly × 3 doses) or intraperitoneal carbachol (60 μg/kg) was given 24 hours after induction of AP. Both CQCQD and carbachol decreased the severity of pancreatic and colonic histopathology (all P < 0.05). Both CQCQD and carbachol reduced serum intestinal fatty acid binding protein, vasoactive intestinal peptide, and substance P and increased motility levels. CQCQD upregulated SMC phospholipase C-beta 1 (PLC-β1) mRNA and PLC protein (both P < 0.05), while both treatments upregulated protein kinase C-alpha (PKC-α) mRNA and PKC protein and downregulated adenylate cyclase (AC) mRNA and protein compared with no treatment (all P < 0.05). Neither treatment significantly altered L-arginine-induced PKC-β1 and PKC-ε mRNA reduction. Both treatments significantly increased fluorescence intensity of SMC intracellular calcium concentration [Ca²⁺]_i (3563.5 and 3046.9 versus 1086.9, both P < 0.01). These data suggest CQCQD and carbachol improve intestinal motility in AP by increasing [Ca²⁺]_i in colonic SMCs via upregulating PLC, PKC and downregulating AC.

Meta-analysis of gut barrier dysfunction in patients with acute pancreatitis

BACKGROUND

The gut is implicated in the pathogenesis of acute pancreatitis but there is discrepancy between individual studies regarding the prevalence of gut barrier dysfunction in patients with acute pancreatitis. The aim of this study was to determine the prevalence of gut barrier dysfunction in acute pancreatitis, the effect of different co-variables, and changes in gut barrier function associated with the use of various therapeutic modalities.

METHODS

A literature search was performed using PRISMA and MOOSE guidelines. Summary estimates were presented as pooled prevalence of gut barrier dysfunction and the associated 95 per cent c.i.

RESULTS

A total of 44 prospective clinical studies were included in the systematic review, of which 18 studies were subjected to meta-analysis. The pooled prevalence of gut barrier dysfunction was 59 (95 per cent c.i. 48 to 70) per cent; the prevalence was not significantly affected by disease severity, timing of assessment after hospital admission or type of test used, but showed a statistically significant association with age. Overall, nine of 13 randomized clinical trials reported a significant improvement in gut barrier function following intervention compared with the control group, but only three of six studies that used standard enteral nutrition reported a statistically significant improvement in gut barrier function after intervention.

CONCLUSION

Gut barrier dysfunction is present in three of five patients with acute pancreatitis, and the prevalence is affected by patient age but not by disease severity. Clinical studies are needed to evaluate the effect of enteral nutrition on gut function in acute pancreatitis.

Microbial translocation and liver disease progression in women coinfected with HIV and hepatitis C virus

BACKGROUND

Microbial translocation has been implicated in the pathogenesis of liver fibrosis and cirrhosis. We sought to determine whether markers of microbial translocation are associated with liver disease progression during coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV).

METHODS

We measured serial plasma lipopolysaccharide (LPS), endotoxin core antibody, intestinal fatty acid-binding protein (I-FABP), soluble CD14 (sCD14), interleukin 6 (IL-6), interleukin 10, and tumor necrosis factor α (TNF-α) levels over a 5-year period in 44 HIV/HCV-coinfected women, 21 of whom experienced liver disease progression and 23 were nonprogressors.

RESULTS

While LPS levels did not differ significantly over time between progressors and nonprogressors (P = .60), progressors had significantly higher plasma levels of sCD14, a marker of monocyte activation by LPS, at the first time point measured (P = .03) and throughout the study period (P = .001); progressors also had higher IL-6 and I-FABP levels over the 5-year study period (P = .02 and .03, respectively). The associations between progression and sCD14, I-FABP, and IL-6 levels were unchanged in models controlling for HIV RNA and CD4(+) T-cell count.

CONCLUSIONS

Although LPS levels did not differ between liver disease progressors and nonprogressors, the association of sCD14, I-FABP, and IL-6 levels with liver disease progression suggests that impairment of gut epithelial integrity and consequent microbial translocation may play a role in the complex interaction of HIV and HCV pathogenesis.

Pancreatic stellate cells: a starring role in normal and diseased pancreas

While the morphology and function of cells of the exocrine and endocrine pancreas have been studied over several centuries, one important cell type in the gland, the pancreatic stellate cell (PSC), had remained undiscovered until as recently as 20 years ago. Even after its first description in 1982, it was to be another 16 years before its biology could begin to be studied, because it was only in 1998 that methods were developed to isolate and culture PSCs from rodent and human pancreas. PSCs are now known to play a critical role in pancreatic fibrosis, a consistent histological feature of two major diseases of the pancreas—chronic pancreatitis and pancreatic cancer. In health, PSCs maintain normal tissue architecture via regulation of the synthesis and degradation of extracellular matrix (ECM) proteins. Recent studies have also implied other functions for PSCs as progenitor cells, immune cells or intermediaries in exocrine pancreatic secretion in humans. During pancreatic injury, PSCs transform from their quiescent phase into an activated, myofibroblast-like phenotype that secretes excessive amounts of ECM proteins leading to the fibrosis of chronic pancreatitis and pancreatic cancer. An ever increasing number of factors that stimulate and/or inhibit PSC activation via paracrine and autocrine pathways are being identified and characterized. It is also now established that PSCs interact closely with pancreatic cancer cells to facilitate cancer progression. Based on these findings, several therapeutic strategies have been examined in experimental models of chronic pancreatitis as well as pancreatic cancer, in a bid to inhibit/retard PSC activation and thereby alleviate chronic pancreatitis or reduce tumor growth in pancreatic cancer. The challenge that remains is to translate these pre-clinical developments into clinically applicable treatments for patients with chronic pancreatitis and pancreatic cancer.

Pathophysiology of acute pancreatitis: potential application from experimental models and human medicine to dogs

The cellular events leading to pancreatitis have been studied extensively in experimental models. Understanding the cellular events and inciting causes of the multisystem inflammatory cascades that are activated with this disease is of vital importance to advance diagnosis and treatment of this condition. Unfortunately, the pathophysiology of pancreatitis in dogs is not well understood, and extrapolation from experimental and human medicine is necessary. The interplay of the inflammatory cascades (kinin, complement, cytokine) is extremely complex in both initiating leukocyte migration and perpetuating disease. Recently, nitric oxide (NO) and altered microcirculation of the pancreas have been proposed as major initiators of inflammation. In addition, the role of the gut is becoming increasingly explored as a cause of oxidative stress and potentiation of systemic inflammation in pancreatitis.

The fibrosis of chronic pancreatitis: new insights into the role of pancreatic stellate cells

SIGNIFICANCE

Prominent fibrosis is a major histological feature of chronic pancreatitis, a progressive necroinflammatory condition of the pancreas, most commonly associated with alcohol abuse. Patients with this disease often develop exocrine and endocrine insufficiency characterized by maldigestion and diabetes. Up until just over a decade ago, there was little understanding of the pathogenesis of pancreatic fibrosis in chronic pancreatitis.

RECENT ADVANCES

In recent times, significant progress has been made in this area, mostly due to the identification, isolation, and characterization of the cells, namely pancreatic stellate cells (PSCs) that are now established as key players in pancreatic fibrogenesis. In health, PSCs maintain normal tissue architecture via regulation of the synthesis and degradation of extracellular matrix (ECM) proteins. During pancreatic injury, PSCs transform into an activated phenotype that secretes excessive amounts of the ECM proteins that comprise fibrous tissue.

CRITICAL ISSUES

This Review summarizes current knowledge and critical aspects of PSC biology which have been increasingly well characterized over the past few years, particularly with respect to the response of PSCs to factors that stimulate or inhibit their activation and the intracellular signaling pathways governing these processes. Based on this knowledge, several therapeutic strategies have been examined in experimental models of pancreatic fibrosis, demonstrating that pancreatic fibrosis is a potentially reversible condition, at least in early stages.

FUTURE DIRECTIONS

These will involve translation of the laboratory findings into effective clinical approaches to prevent/inhibit PSC activation so as to prevent, retard, or reverse the fibrotic process in pancreatitis.

Increased microbial translocation in ≤ 180 days old perinatally human immunodeficiency virus-positive infants as compared with human immunodeficiency virus-exposed uninfected infants of similar age

BACKGROUND

The effect of early versus deferred antiretroviral treatment (ART) on plasma concentration of lipopolysaccharide (LPS) and host LPS-binding molecules in human immunodeficiency virus (HIV)-infected infants up to 1 year of age was investigated.

METHODS

We evaluated 54 perinatally HIV-infected and 22 HIV-exposed uninfected infants (controls) at the first and second semester of life. All HIV-infected infants had a baseline CD4 of ≥ 25%, participated in the Comprehensive International Program of Research on AIDS Children with HIV Early Antiretroviral Therapy trial in South Africa, and were randomized in the following groups: group 1 (n = 20), ART deferred until CD4 < 25% or severe HIV disease; and group 2 (n = 34), ART initiation within 6 to 12 weeks of age. LPS, endotoxin-core antibodies, soluble CD14 (sCD14), and LPS-binding protein (LBP) were measured in cryopreserved plasma. T-cell activation was measured in fresh whole blood.

RESULTS

At the first semester, LPS concentration was higher in HIV-infected infants than in controls; sCD14, LBP, and T-cell activation were higher in group 1 than in group 2 and controls. Although LPS was not correlated with study variables, viral load was positively associated with sCD14, LBP, or endotoxin-core antibodies. At the second semester, LPS was not detectable and elevated host LPS-control molecules values were sustained in all groups and in conjunction with ART in all HIV-infected infants.

CONCLUSIONS

Although plasma concentration of LPS was higher in perinatally HIV-infected infants 0 to 6 months of age than in controls independent of ART initiation strategy, concentration of LPS-control molecules was higher in infants with deferred ART, suggesting the presence of increased microbial translocation in HIV-infected infants with sustained early viral replication.

Gut barrier dysfunction in critically ill surgical patients with abdominal compartment syndrome

OBJECTIVES

This study investigated the effects of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) on gut barrier function in critically ill surgical patients.

METHODS

A prospective observational cohort study on patients with severe acute pancreatitis or abdominal sepsis admitted to an intensive care or high-dependency unit. Intra-abdominal pressure (IAP) and plasma levels of immunoglobulin G (IgG) and IgM antiendotoxin core antibodies (EndoCAb) and procalcitonin (ProCT) were measured serially.

RESULTS

Among 32 recruited patients, 24 (75%) and 8 patients (25%) developed IAH and ACS, respectively. The state of ACS was associated with significant reductions in plasma IgG EndoCAb (P = 0.015) and IgM EndoCAb (P = 0.016) and higher concentrations of plasma ProCT (P = 0.056) compared with absence of ACS. Resolution of IAH and ACS was associated with significant recovery of plasma IgG EndoCAb (P = 0.003 and P = 0.009, respectively) and IgM EndoCAb (P = 0.002 and P = 0.003, respectively) and reduction in plasma ProCT concentration (P = 0.049 and P = 0.019, respectively). Negative correlations were observed between IAP and plasma IgG EndoCAb (P = 0.003) and IgM EndoCAb (P = 0.002).

CONCLUSIONS

Intra-abdominal hypertension and ACS are associated with significantly higher endotoxin exposure and ProCT concentrations, suggestive of gut barrier dysfunction. Resolution of IAH and ACS is associated with evidence for recovery of gut barrier function.

Enteral ecoimmunonutrition support alleviates hepatic injury in patients with severe acute pancreatitis

AIM: To explore the effects of different nutritional support regimens on hepatic injury in patients with severe acute pancreatitis (SAP).

METHODS: Eighty-six SAP patients with hepatic injury were randomly divided into three groups: parenteral nutrition (PN) group (n = 28), enteral nutrition (EN) group (n = 29) and ecoimmunonutrition (EIN) group (n = 29). All the patients received nutritional support for 14 days. The changes in plasma endotoxin and serum cytokine levels and hepatic function were determined.

RESULTS: The baseline levels of plasma endotoxin and serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) had no significant differences among the three groups. After 14 days of nutrition support, the levels of plasma endotoxin and serum TNF-α and IL-6 in the EIN group were 1.28 ng/L ± 0.17 ng/L, 30.13 ng/L ± 8.12 ng/L and 36.43 ng/L ± 8.24 ng/L, respectively, all significantly lower than those in the PN group and EN group (all P < 0.01 or 0.05). The hepatic function in the EIN group returned to normal levels after 14 days of nutrition support. The improvement in hepatic function achieved in the EIN group was significantly better than that achieved in the EN group.

CONCLUSION: EIN can help recover the balance of normal flora in the gut, reduce bacterial translocation, modulate immunological function, and attenuate the level of plasma endotoxin and serum cytokines, thereby alleviating hepatic injury in patients with SAP.

Monocyte TREM-1 membrane expression in non-infectious inflammation

Sterile or non-infectious inflammation and severe infection are accompanied by very similar events. Damage (or danger)-associated molecular patterns and pathogen-associated molecular patterns trigger the release of inflammatory mediators and modulate the expression of cell surface receptors. The increased expression on monocytes and neutrophils of triggering receptor expressed on myeloid cells 1 is a hallmark of both infectious and non-infectious inflammation.

Delayed loss of control of plasma lipopolysaccharide levels after therapy interruption in chronically HIV-1-infected patients

OBJECTIVE

Increased circulating levels of lipopolysaccharide (LPS) have been demonstrated in HIV-1-infected progressors. We investigated the effect of antiretroviral therapy (ART) interruptions on plasma LPS levels.

DESIGN AND METHODS

Overall, 77 individuals participated in this study (51 HIV-positive and 26 healthy). Ten out of 51 HIV-positive participants were viremic ART-naive patients and 41 out of 51 were chronically suppressed patients on ART (three or more drugs, CD4 cell count more than 400 cells/microl, HIV-1 RNA less than 500 copies/ml for more than 8 months, less than 50 copies/ml at recruitment) undergoing therapy interruption. The limulus amebocyte assay was used to measure plasma LPS levels; enzyme-linked immunosorbent assay to measure plasma levels of endotoxin-core antibodies (EndoCAb), soluble (s)CD14, LPS-binding protein and IFN-alpha; immunoblotting to measure plasma gelsolin levels; and same day whole blood flow cytometry to measure levels of T-cell-activation markers (CD8/CD38, CD8/HLA-DR and CD3/CD95).

RESULTS

Increases in viremia and T-cell-activation markers were observed during therapy interruptions. During short-term therapy interruptions of less than 12 weeks, no change in LPS levels was found, whereas negative associations between viral load and LPS levels (Spearman's Rho = -0.612, P = 0.0152), viral load and EndoCAb change (DeltaEndoCAb, correlation = -0.502, P = 0.0204), and between DeltaLPS and DeltaEndoCAb (correlation = -0.851, P = 0.0073) were observed. In contrast, increased LPS (P = 0.0171) and sCD14 (P < 0.0001) levels were observed during long-term therapy interruption of more than 12 weeks compared with levels during ART, together with no association between LPS and viral load or EndoCAb. No association between immune activation and LPS was evident at any time point.

CONCLUSION

Increased plasma LPS levels were observed only after more than 12 weeks of ART interruption, despite presence of LPS-controlling host mechanisms.

Usefulness of serum IgG4 in the diagnosis and follow up of autoimmune pancreatitis: A systematic literature review and meta-analysis

High circulating serum immunoglobulin G4 (IgG4) levels have been proposed as a marker of autoimmune pancreatitis (AIP). The aim of the present study was to review the data existing in the English literature on the usefulness of the IgG4 serum levels in the diagnosis and follow up of patients with AIP. A total of 159 patients with AIP and 1099 controls were described in seven selected papers reporting the usefulness of serum IgG4 in diagnosing AIP. In total, 304 controls had pancreatic cancer, 96 had autoimmune diseases, and the remaining 699 had other conditions. The summary receiver-operating characteristic curve analysis was carried out by means of Meta-DiSc open-access software. Serum IgG4 showed good accuracy in distinguishing between AIP and the overall controls, pancreatic cancer and other autoimmune diseases (area under the curve [+/- SE]: 0.920 +/- 0.073, 0.914 +/- 0.191, and 0.949 +/- 0.024, respectively). The studies analyzed showed significantly heterogeneous specificity values in each of the three analyses performed. The analysis of the four studies comparing AIP and pancreatic cancers also showed significantly heterogeneous values of sensitivities and odds ratios. Regarding the usefulness of IgG4 as a marker of efficacy of steroid treatment, a decrease in the serum concentrations of IgG4 was found in the four available studies. The serum IgG4 subclass is a good marker of AIP, and its determination should be included in the diagnostic workup of this disease. However, the heterogeneity of the studies published until now means that more studies are necessary in order to better evaluate the true accuracy of IgG4 in discriminating AIP versus other autoimmune diseases.

Assessment of the severity of acute pancreatitis: no room for complacency

Assessing the severity of acute pancreatitis is an important initial step in the management of these patients. An ideal prognostic system or marker does not exist, and current approaches fall short of what is needed when dealing with individual patients. It is recommended that the evaluation of the performance of a particular prognostic system or marker should include the calculation of positive and negative likelihood ratios, derived from a combination of sensitivity and specificity. Knowing the pre-test probability of a particular endpoint and the likelihood ratios make it possible to derive the post-test probability for the presence or absence of that endpoint for the individual patient in that population. The change in probability from before to after the test gives an indication of the clinical usefulness of the test. Improving the performance of prognostic systems and markers remains a challenge and there is no room for complacency. There are two ways forward: either the prognostic systems and markers need to be used in a more intelligent way, with combinations, sequencing or artificial neural network techniques, or by the discovery of new markers that measure critical aspects of outcome determining pathophysiology. No lack of energy has been expended on the latter, while the former offers more immediate promise.

The pathogenic mechanism of severe acute pancreatitis complicated with renal injury: a review of current knowledge

The onset of severe acute pancreatitis (SAP) is clinically harmful as it may rapidly progress from a local pancreatic inflammation into proemial systemic inflammatory reactions. Patients with SAP have a high mortality, with most cases of death resulting from complications involving the failure of organs other than the pancreas. The distinctive feature of SAP is that once it starts, it may aggrevate the clinical condition of the patient continuously, so that the levels of injury to the other organs surpass the severity of the pancreatic lesion, even causing multiple organ failure and, ultimately, death. In clinical practice, the main complications in terms of organ dysfunctions are shock, acute respiratory failure, acute renal failure, among others. The acute renal injury caused by SAP is not only able to aggravate the state of pancreatitis, but it also develops into renal failure and elevates patients' mortality. Studies have found that the injury due to massive inflammatory mediators, microcirculation changes and apoptosis, among others, may play important roles in the pathogenic mechanism of acute renal injury.

A high-fat meal induces low-grade endotoxemia: evidence of a novel mechanism of postprandial inflammation

BACKGROUND

Bacterial endotoxin is a potently inflammatory antigen that is abundant in the human gut. Endotoxin circulates at low concentrations in the blood of all healthy individuals, although elevated concentrations are associated with an increased risk of atherosclerosis.

OBJECTIVE

We sought to determine whether a high-fat meal or smoking increases plasma endotoxin concentrations and whether such concentrations are of physiologic relevance.

DESIGN

Plasma endotoxin and endotoxin neutralization capacity were measured for 4 h in 12 healthy men after no meal, 3 cigarettes, a high-fat meal, or a high-fat meal with 3 cigarettes by using the limulus assay.

RESULTS

Baseline endotoxin concentrations were 8.2 pg/mL (interquartile range: 3.4-13.5 pg/mL) but increased significantly (P < 0.05) by approximately 50% after a high-fat meal or after a high-fat meal with cigarettes but not after no meal or cigarettes alone. These results were validated by the observations that a high-fat meal with or without cigarettes, but not no meal or smoking, also significantly (P < 0.05) reduced plasma endotoxin neutralization capacity, which is an indirect measure of endotoxin exposure. Human monocytes, but not aortic endothelial cells, were responsive to transient (30 s) or low-dose (10 pg/mL) exposure to endotoxin. However, plasma from whole blood treated with as little as 10 pg endotoxin/mL increased the endothelial cell expression of E-selectin, at least partly via tumor necrosis factor-alpha-induced cellular activation.

CONCLUSIONS

Low-grade endotoxemia may contribute to the postprandial inflammatory state and could represent a novel potential contributor to endothelial activation and the development of atherosclerosis.

Severe acute pancreatitis: Clinical course and management

Severe acute pancreatitis (SAP) develops in about 25% of patients with acute pancreatitis (AP). Severity of AP is linked to the presence of systemic organ dysfunctions and/or necrotizing pancreatitis pathomorphologically. Risk factors determining independently the outcome of SAP are early multi-organ failure, infection of necrosis and extended necrosis (>50%). Up to one third of patients with necrotizing pancreatitis develop in the late course infection of necroses. Morbidity of SAP is biphasic, in the first week strongly related to early and persistence of organ or multi-organ dysfunction. Clinical sepsis caused by infected necrosis leading to multi-organ failure syndrome (MOFS) occurs in the later course after the first week. To predict sepsis, MOFS or deaths in the first 48-72 h, the highest predictive accuracy has been objectified for procalcitonin and IL-8; the Sepsis-Related Organ Failure Assessment (SOFA)-score predicts the outcome in the first 48 h, and provides a daily assessment of treatment response with a high positive predictive value. Contrast-enhanced CT provides the highest diagnostic accuracy for necrotizing pancreatitis when performed after the first week of disease. Patients who suffer early organ dysfunctions or at risk of developing a severe disease require early intensive care treatment. Early vigorous intravenous fluid replacement is of foremost importance. The goal is to decrease the hematocrit or restore normal cardiocirculatory functions. Antibiotic prophylaxis has not been shown as an effective preventive treatment. Early enteral feeding is based on a high level of evidence, resulting in a reduction of local and systemic infection. Patients suffering infected necrosis causing clinical sepsis, pancreatic abscess or surgical acute abdomen are candidates for early intervention. Hospital mortality of SAP after interventional or surgical debridement has decreased in high volume centers to below 20%.

Severe acute pancreatitis: Clinical course and management

Severe acute pancreatitis (SAP) develops in about 25% of patients with acute pancreatitis (AP). Severity of AP is linked to the presence of systemic organ dysfunctions and/or necrotizing pancreatitis pathomorphologically. Risk factors determining independently the outcome of SAP are early multi-organ failure, infection of necrosis and extended necrosis (> 50%). Up to one third of patients with necrotizing pancreatitis develop in the late course infection of necroses. Morbidity of SAP is biphasic, in the first week strongly related to early and persistence of organ or multi-organ dysfunction. Clinical sepsis caused by infected necrosis leading to multi-organ failure syndrome (MOFS) occurs in the later course after the first week. To predict sepsis, MOFS or deaths in the first 48-72 h, the highest predictive accuracy has been objectified for procalcitonin and IL-8; the Sepsis-Related Organ Failure Assessment (SOFA)-score predicts the outcome in the first 48 h, and provides a daily assessment of treatment response with a high positive predictive value. Contrast-enhanced CT provides the highest diagnostic accuracy for necrotizing pancreatitis when performed after the first week of disease. Patients who suffer early organ dysfunctions or at risk of developing a severe disease require early intensive care treatment. Early vigorous intravenous fluid replacement is of foremost importance. The goal is to decrease the hematocrit or restore normal cardiocirculatory functions. Antibiotic prophylaxis has not been shown as an effective preventive treatment. Early enteral feeding is based on a high level of evidence, resulting in a reduction of local and systemic infection. Patients suffering infected necrosis causing clinical sepsis, pancreatic abscess or surgical acute abdomen are candidates for early intervention. Hospital mortality of SAP after interventional or surgical debridement has decreased in high volume centers to below 20%.

Study progress on mechanism of severe acute pancreatitis complicated with hepatic injury

Study on the action mechanism of inflammatory mediators generated by the severe acute pancreatitis (SAP) in multiple organ injury is a hotspot in the surgical field. In clinical practice, the main complicated organ dysfunctions are shock, respiratory failure, renal failure, encephalopathy, with the rate of hepatic diseases being closely next to them. The hepatic injury caused by SAP cannot only aggravate the state of pancreatitis, but also develop into hepatic failure and cause patient death. Its complicated pathogenic mechanism is an obstacle in clinical treatment. Among many pathogenic factors, the changes of vasoactive substances, participation of inflammatory mediators as well as OFR (oxygen free radical), endotoxin, etc. may play important roles in its progression.

Influence of different nutritional support with compound lactobacilli on intestinal barrier function of rats with severe acute pancreatitis

AIM: To investigate the influence of different nutritional support with compound lactobacilli on the intestinal barrier function in rats with severe acute pancreatitis (SAP) and its mechanism.

METHODS: SAP model was established in male Sprague Dawley rats via injection of l mL of 38 g/L sodium taurocholate beneath the pancreatic capsule. A total of 96 rats were randomly divided into 6 groups (n = 16): sham-operation with early enteral nutrition support (Sham-EEN), ENN group, EEN with compound lactobacilli (EEN + Lac) group, sham-operation with parenteral nutrition support (Sham-PN), PN group and PN with compound lactobacilli (PN + Lac) group. Half of rats in each group were killed on the 4^th and 7^th day respectively to determine the bacterial translocation (BT) in live and mesenteric lymph node (MLN), endotoxin (ET) in plasma, intestinal transit index, epithelial cell apoptosis in intestinal barrier (by TUNEL), protein content in small intestinal mucosa (by bicinchoninic acid), and SIgA content in small intestinal mucus (by enzyme-linked immunosorbent assay).

RESULTS: The rate of BT in PN group was higher than that in EEN and PN + Lac group (14/16 vs 9/16, 10/16, both P < 0.05), and there was also a significant difference between EEN and EEN + Lac group on the 4^th day (12/16 vs 9/16, P = 0.026). As compared with that in EEN group, the level of ET in plasma was higher in PN group (276.83 ± 30.81 EU/L vs 138.52 ± 22.56 EU/L, P < 0.05), and it was also higher in groups without Lac than that in the groups with Lac (all P < 0.05). Intestinal transit index was significantly increased in PN + Lac group in comparison with that in PN group (0.70 ± 0.08 vs 0.59 ± 0.05, P < 0.01). As compared with that in EEN group and PN + Lac group, intestinal epithelial apoptosis was higher in PN group (22.67% ± 4.97% vs 15.31% ± 4.18%, 18.40% ± 2.01%, P < 0.01). The protein content in small intestinal mucosa was higher in groups with Lac than that in the groups without Lac (all P < 0.05), and it was also increased significantly in PN + Lac group as compared with that in EEN + Lac group (56.91 ± 3.73 mg/g vs 44.69 ± 2.99 mg/g, P < 0.01). In comparison with that in EEN and PN + Lac group, SIgA content in small intestinal mucus was significantly higher in EEN + Lac group (82.17 ± 6.02 μg/g vs 69.26 ± 5.66 μg/g, 59.87 ± 5.54 μg/g, P < 0.05 and P < 0.01).

CONCLUSION: EEN and PN with compound lactobacilli can dramatically benefit the intestinal barrier function SAP rats, and the former is superior to the latter.

Effect of early continuous high-volume hemofiltration on histopathological changes of pancreas and extrapancreatic organs in pigs with severe acute pancreatitis

AIM: To observe the effect of early continuous high-volume hemofiltration on the histopatho-logical changes of pancreas and extrapancreatic organs in pigs with severe acute pancreatitis (SAP).

METHODS: Twenty-four domestic pigs were randomly and averagely assigned into 3 groups: control group (untreated model group) as group A, low-volume hemofiltration [20 mL/(kg·h)] group as group B, and high-volume hemofiltration [100 mL/(kg·h)] group as group C. SAP model was produced by injection of sodium taurocholate (40 g/L, 1 mL/kg) and trypsin (2 U/kg) via the pancreatic duct. The pigs in group B and C received hemofiltration immediately after modeling. The parameters including survival time and histopathological scores of pancreas and extra-pancreatic organs were observed.

RESULTS: The median survival times were 41, 50 and 65 h in group A, B, and C, respectively, and there were significant differences among them (P < 0.01). The histopathological scores had no marked differences between the three groups (P > 0.05). However, the scores for hepatocellular degeneration, pulmonary hyaline membranes and microthrombi, and renal tubular damage were obviously lower than those in the other groups (P < 0.05).

CONCLUSION: Although hemofiltration can not reduce the pancreatic damage in pigs with SAP, early continuous high-volume hemofiltration can significantly ameliorate the hepatocellular degeneration, the formation of pulmonary hyaline membranes and microthrombi, and the renal tubular damage in pigs with SAP, which is useful in improving the survival time.

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Acute necrotising pancreatitis following grain overload in a donkey

A donkey developed abdominal discomfort and distension together with cardiovascular collapse and gastric reflux 24 to 36 hours after ingesting a large amount of poultry feed. Rectal findings prompted a laparotomy that identified extensive gastric dilation, an empty, atonic small intestine, dry colonic content and an easily corrected caecal displacement. These findings were not consistent with the severity of the signs, which were attributed to endotoxaemia. The donkey was euthanased during recovery. Necropsy revealed acute necrotising pancreatitis with massive gastric dilation and right dorsal colon impaction. The clinicopathological features of acute equine pancreatitis associated with grain overload are discussed.

A study of intestinal permeability in relation to the inflammatory response and plasma endocab IgM levels in patients with acute pancreatitis

BACKGROUND

There is scarce information regarding intestinal permeability (IP) in patients with acute pancreatitis (AP) and its relationship with systemic inflammatory response and bacterial translocation (BT).

AIMS

To study IP in patients with mild and severe forms of AP as compared with controls and the presumed correlations between IP, the inflammatory response, and endotoxin.

PATIENTS AND METHODS

Sixty-eight patients with AP and 13 healthy controls were included. IP was assessed by means of the lactulose/mannitol (L/M) test, at admission (LMR1), and at the 15th day (LMR2). The presence of endotoxin was assessed by means of endotoxin-core antibodies type IgM (EndoCab IgM), at admission and 15 days later in patients with severe AP. Plasma levels of interleukins 6, 8, 10, and tumor necrosis factor alpha were tested within the first 72 hours from the onset of pain.

RESULTS

Both LMR1 and LMR2 were significantly higher in patients than in controls, and in patients with severe versus mild forms of AP. Plasma levels of Endocab IgM increased significantly in patients with severe AP. Basal plasma levels of pro- and anti-inflammatory cytokines were significantly higher in patients with severe AP. A significant correlation was found between LMR2 and Endocab IgM levels in patients with severe AP (r = 0.73, P = 0.02).

CONCLUSIONS

Patients with AP show an increased IP when compared with controls, being more relevant and persistent in severe cases. This seems related to an increase of endotoxemia late in the course of the disease, but not with an exacerbation of the systemic immune response.

Efficacy of serum nitric oxide level estimation in assessing the severity of necrotizing pancreatitis

BACKGROUND

The role of nitric oxide in the pathophysiology of necrotizing pancreatitis is unclear.

METHODS

In a prospective study, the clinical course of 40 patients diagnosed as having acute necrotizing pancreatitis was followed using computed tomography severity score (CTSS) and serial APACHE II scoring. The serum nitric oxide levels in the form of reactive nitrogen intermediates (RNI) were estimated on admission and on day 3. Occurrence of complications, need for intervention, incidence of organ failure, and outcome were noted. The efficacy of CTSS, APACHE II scores, and RNI levels in predicting morbidity and mortality was assessed. The correlation between CTSS, APACHE II scores, and RNI levels was studied.

RESULTS

The study group showed significantly higher levels of RNI as compared with the control group (159.1 vs. 106.0 nmol/ml, p < 0.05). The RNI levels were not affected by the occurrence of local complications or distant-organ failure. The RNI levels on admission were significantly higher in the subset of patients who developed bacterial sepsis (195.5 vs. 134.7 nmol/ml, p < 0.05). The RNI levels on admission in the non-survivors were higher as compared with those of the survivors (216.0 vs. 140.1 nmol/ml, p < 0.05). There was a significant positive correlation between the RNI levels and the CTSS in these patients (p < 0.05). There was no correlation between RNI levels and APACHE II scores.

CONCLUSIONS

Acute necrotizing pancreatitis is associated with raised serum nitric oxide levels at its early stage. Patients with higher serum nitric oxide levels are at a significantly higher risk of sepsis and mortality.

Calcitonin precursors: early markers of gut barrier dysfunction in patients with acute pancreatitis

BACKGROUND

Severe acute pancreatitis is associated with an early increase in intestinal permeability and endotoxemia. Endotoxin is a potent stimulator for the production and release of procalcitonin and its components (calcitonin precursors; [CTpr]). The aim of this study is to evaluate the role of plasma CTpr as an early marker for gut barrier dysfunction in patients with acute pancreatitis.

METHODS

Intestinal permeability to macromolecules (polyethylene glycol 3350), serum endotoxin and antiendotoxin core antibodies, plasma CTpr, and serum C-reactive protein (CRP) were measured on admission in 60 patients with acute pancreatitis. Attacks were classified as mild (n = 48) or severe (n = 12) according to the Atlanta criteria.

RESULTS

Compared with mild attacks of acute pancreatitis, severe attacks were significantly associated with an increase in intestinal permeability index (median: 0.02 vs. 0.006, P < 0.001), the frequency of endotoxemia (73% vs. 41%, P = 0.04), and the extent of depletion of serum IgM antiendotoxin antibodies (median: 43 MMU vs. 100 MMU, P = 0.004). Plasma CTpr levels were significantly elevated in patients with severe attacks compared with mild attacks on both the day of admission and on day 3 (median: 64 vs. 22 fmol/mL, P = 0.03; and 90 vs. 29 fmol/mL, P = 0.003 respectively). A positive and significant correlation was observed between the admission serum endotoxin and plasma CTpr levels on admission (r = 0.7, P < 0.0001) and on day 3 (r = 0.96, P < 0.0001), and between plasma CTpr on day 7 and the intestinal permeability index (r = 0.85, P = 0.0001). In contrast, only a weak positive correlation was observed between peak serum levels of CRP and plasma CTpr on admission (r = 0.3, P = 0.017) and on day 7 (r = 0.471, P = 0.049), as well as between CRP and each of the admission serum endotoxin (r = 0.3, P = 0.03) and the intestinal permeability index (r = 0.375, P = 0.007).

CONCLUSIONS

In patients with acute pancreatitis, plasma concentrations of CTpr appear to reflect more closely the derangement in gut barrier function rather than the extent of systemic inflammation.

Association of two polymorphisms of tumor necrosis factor gene with acute severe pancreatitis

BACKGROUND

Acute severe pancreatitis (ASP) has an unpredictable course and outcome. Polymorphisms of the tumor necrosis factor (TNF) gene have been related to TNF production and outcome in a variety of inflammatory diseases. We assessed whether TNF gene polymorphism and plasma concentrations of TNF-alpha were related to the occurrence of ASP and septic shock from it.

METHODS

The study included 208 patients (102 with ASP, 106 with acute mild pancreatitis) and 116 healthy volunteers. TNF-beta and TNF-alpha-308 polymorphisms were performed by analyzing NcoI-digested DNA fragment obtained by polymerase chain reaction (PCR). HLA-DRB1*0301 (HLA-DR3) typing was performed by sequence-specific oligonucleotide typing on PCR-amplified genomic DNA. Plasma concentrations of TNF-alpha were measured by solid-phase enzyme-amplified sensitivity immunoassay.

RESULTS

The overall TNF2 allele frequency and TNFB2 allele frequency were similar in patients with mild or severe pancreatitis. Further, no significant difference in gene polymorphism frequencies was noted between patients with acute pancreatitis and controls. TNF2 frequency was significantly increased in septic shock patients compared with nonseptic shock patients (53.8 vs 22.4%; P = 0.003), as was TNFB2 frequency (88.5 vs 63.2%; P = 0.015). A linkage disequilibrium between TNF2 allele and HLA-DR3 was seen, this haplotype was not associated with severity of acute pancreatitis or outcome of septic shock in ASP patients. With regard to the mortality rate in patients who developed septic shock, those with a TNF2 allele had a significantly higher rate of mortality than those with a TNF1 allele (expired: 8 vs 1, P = 0.018). Plasma levels of TNF-alpha did not differ significantly in ASP patients displaying different alleles of the TNF gene studied.

CONCLUSIONS

Results indicate that the TNF gene polymorphisms studied play no part in determination of disease severity or ASP susceptibility; however, they are both strongly related to the development of septic shock in ASP. TNF2 allele was associated with death as a result of ASP-associated septic shock.

Early activation of peripheral lymphocytes in human acute pancreatitis

BACKGROUND

The CD69 antigen is an indicator of early lymphocyte activation.

GOALS

To evaluate the early activation of peripheral lymphocytes T, B, and NK in patients with acute pancreatitis in comparison with patients with acute abdomen of nonpancreatic origin.

STUDY

Thirty patients with acute pancreatitis were studied; 20 of them had the mild form of the disease and 10 had the severe form. Thirty patients with nonpancreatic acute abdomen were used as controls. All patients were enrolled within 48 hours of the onset of pain. In all patients, leukocytes and total lymphocyte and lymphocyte subset counts (CD4+, CD8+, CD56+, CD19+, CD4+CD69+, CD8+CD69+, CD56+CD69+, CD19+CD69+) were determined upon hospital admission.

RESULTS

The percentage of total lymphocytes was significantly lower in acute pancreatitis patients than in those with nonpancreatic acute abdomen (P = 0.014); patients with severe pancreatitis had a percentage of total lymphocytes significantly lower when compared with patients with mild pancreatitis (P < 0.001). The CD19+CD69+ count was significantly lower in patients with severe pancreatitis (24.6 +/- 14.6%) than in patients with mild pancreatitis (46.7 +/- 16.5%; = 0.006). The counts of the other lymphocyte subsets were not statistically different between patients with acute pancreatitis and those with nonpancreatic acute abdomen, as well as between patients with mild and severe acute pancreatitis.

CONCLUSIONS

Patients with severe pancreatitis show impaired early activation of peripheral CD19+ cells.

Role of the gut in the course of severe acute pancreatitis

INTRODUCTION

The pathogenesis of acute pancreatitis remains elusive. Sepsis and multiple organ failure continue to cause death (overall mortality rate, approximately 10%) despite immense improvements in supportive, radiologic, and surgical therapy. The gut appears to play a key role in the development of these complications.

AIM

To critically review the evidence implicating the gut in the pathogenesis of acute pancreatitis.

METHODS

Relevant English-language literature or abstracts cited in the MEDLINE database were reviewed.

RESULTS AND CONCLUSION

Gram-negative enteric organisms account for most infections of pancreatic necrosis and subsequent sepsis, which suggests the gut as a source. Intestinal permeability is increased early in patients with severe acute pancreatitis and correlates with endotoxemia, which suggests translocation as a possible mechanism. The pathogenesis of the deranged function of the gut mucosal barrier and the possible sites of increase in intestinal permeability are discussed. The gut also plays a role in priming neutrophils and the release of inflammatory cytokines, which initiate and propagate nearly all the detrimental consequences of severe inflammation and sepsis. Future research avenues and potential therapeutic measures that may restore and preserve gut barrier function are explored.

Host immune responses and intestinal permeability in patients with jaundice

BACKGROUND

Systemic endotoxaemia is implicated in the development of complications associated with obstructive jaundice. The aims of these studies were to assess the systemic immune response to intervention in patients with jaundice and to compare the effects of surgical and non-surgical biliary drainage on host immune function and gut barrier function.

METHODS

In the first study, 18 jaundiced and 12 control patients were studied to assess systemic immune responses before and after intervention. In the second study, immune responses and gut barrier function were assessed following surgical and non-operative biliary decompression in 45 patients with jaundice.

RESULTS

Endotoxin antibody concentrations fell significantly in patients with jaundice immediately after surgical intervention, but not after non-operative biliary drainage. This decrease was associated with a significant increase in serum P(55) soluble tumour necrosis factor (sTNF) receptor concentration (5.3 versus 10.5 ng/ml; P < 0.001), urinary excretion of P(55) TNF receptors (21.4 versus 78.8 ng/ml; P = 0.002) and intestinal permeability (lactulose : mannitol ratio 0.032 versus 0.082; P = 0.048). Intestinal permeability was significantly increased in patients with jaundice compared with controls (0.033 versus 0.015; P = 0.002).

CONCLUSION

These data suggest that obstructive jaundice is associated with impaired gut barrier function and activation of host immune function that is exacerbated by intervention. Surgery causes an exaggerated pathophysiological disturbance not seen with non-operative biliary drainage procedures.

The role of the intestine in the pathophysiology and management of severe acute pancreatitis

BACKGROUND

The outcome of severe acute pancreatitis has scarcely improved in 10 years. Further impact will require new paradigms in pathophysiology and treatment. There is accumulating evidence to support the concept that the intestine has a key role in the pathophysiology of severe acute pancreatitis which goes beyond the notion of secondary pancreatic infection. Intestinal ischaemia and reperfusion and barrier failure are implicated in the development of multiple organ failure.

DISCUSSION

Conventional management of severe acute pancreatitis has tended to ignore the intestine. More recent attempts to rectify this problem have included 1) resuscitation aimed at restoring intestinal blood flow through the use of appropriate fluids and splanchnic-sparing vasoconstrictors or inotropes; 2) enteral nutrition to help maintain the integrity of the intestinal barrier; 3) selective gut decontamination and prophylactic antibiotics to reduce bacterial translocation and secondary infection. Novel therapies are being developed to limit intestinal injury, and these include antioxidants and anti-cytokine agents. This paper focuses on the role of the intestine in the pathogenesis of severe acute pancreatitis and reviews the implications for management.

The impact of anti-endotoxin core antibodies on endotoxin and cytokine release and ventilation time after cardiac surgery

OBJECTIVES

We hypothesized that a temporary cardiopulmonary bypass (CPB)-induced reduction of endotoxin antibody levels contributes to elevated endotoxin levels and the associated inflammatory consequences, with a significant influence on the postoperative ventilation time period.

BACKGROUND

Cardiac surgery using CPB induces a systemic inflammatory response syndrome with an associated risk of increased postoperative morbidity and mortality.

METHODS

A total of 100 consecutive patients undergoing elective coronary artery bypass graft surgery using CPB were prospectively investigated. Endotoxin core antibodies (immunoglobulin [Ig] M/IgG against lipid A and lipopolysaccharide), endotoxin, interleukin (IL)-1-beta, IL-6, IL-8 and tumor necrosis factor-alpha were measured serially from 24 h preoperatively until 72 h postoperatively.

RESULTS

Eighty-five patients had no complications (group 1), whereas 15 patients required prolonged ventilation (group 2). In both groups, there was a decrease of all antibodies 5 min after CPB onset, compared with baseline values (p < 0.001), an increase of endotoxin and IL-8 peaking at 30 min postoperatively (p < 0.001) and an increase of IL-6 peaking 3 h postoperatively (p < 0.001). In group 2, preoperative antibody levels were lower (p < 0.01)--specifically, the decrease in IgM was significantly stronger and of longer duration (p < 0.002)--and levels of endotoxin (p < 0.001) and IL-8 (p < 0.001) were higher at 30 min postoperatively.

CONCLUSIONS

We conclude that an CPB-associated temporary reduction of anti-endotoxin core antibody levels contributes to elevated endotoxin and IL-8 release. Furthermore, lower levels of IgM anti-endotoxin core antibodies were associated with a greater rise in endotoxin and IL-8, as well as prolonged respirator dependence.

Endothelial-derived selectins in the development of organ dysfunction in acute pancreatitis

OBJECTIVE

The development of organ dysfunction is the principal determinant of outcome in acute pancreatitis and is mediated through a systemic inflammatory response characterized by leukocyte and endothelial cell activation. Up-regulation of the endothelial cell adhesion molecules, E-selectin and P-selectin, is important for endothelial/leukocyte interactions. Levels of serum-soluble E-selectin and P-selectin have been suggested as markers of endothelial activation. This study examines the kinetics of serum-soluble selectins in patients with acute pancreatitis complicated by organ dysfunction.

DESIGN

Prospective observational study.

SETTING

University teaching hospital with a specialist hepato-pancreatico-biliary service.

PATIENTS

Eighteen patients with acute pancreatitis were studied, nine of whom had organ dysfunction.

MEASUREMENTS AND MAIN RESULTS

Serial venous blood samples were collected on the first 3 days after admission for measurement of soluble E-selectin and P-selectin by enzyme-linked immunosorbent assay. In all patients, soluble P-selectin concentrations decreased significantly during the study period. Nonsurvivors had significantly higher levels of soluble P-selectin than survivors. In contrast, soluble E-selectin increased significantly during the study period in patients with organ dysfunction, whereas it remained constant in patients without evidence of organ dysfunction.

CONCLUSIONS

These results suggest a role for endothelial-derived selectins in the development of organ dysfunction in patients with acute pancreatitis. The observed temporal differences in serum selectin concentrations is in keeping with in vitro observations of endothelial selectin expression.

Endotoxin, cytokines and lipid peroxides in children with intussusception

BACKGROUND

Intussusception is a relatively common paediatric surgical emergency. The aim of this study was to investigate selected inflammatory mediators in children with acute intussusception and to identify potentially useful plasma markers of clinical outcome.

METHODS

Clinical, radiographic, operative and pathological details were recorded prospectively of all children presenting to a single institution with a confirmed diagnosis of acute intussusception during 1 year. Paired acute and convalescent venous blood samples were collected in a standard manner for blinded analysis of the following: malondialdehyde, C-reactive protein (CRP), interleukin (IL) 6, neopterin, tumour necrosis factor alpha, endotoxin, and immunoglobulin (Ig) G and IgM antiendotoxin core antibody (EndoCAb).

RESULTS

Thirty-two consecutive children (23 boys, nine girls) with a median age of 4 months were studied. Acute ileocolic intussusception was managed by air enema reduction (n = 19), operative reduction (n = 8) or surgical resection (n = 5). Peripheral blood cultures were sterile. Acute levels of plasma IL-6, neopterin and CRP were significantly raised in comparison to both normal laboratory ranges and convalescent samples (P < 0.001). Using stepwise discriminant analysis, CRP was identified as the best variable at distinguishing between the three treatment groups (P < 0.001). IgM EndoCAb concentrations were significantly greater in the convalescent sera of all the patients (P < 0.001).

CONCLUSION

Acute ileocolic intussusception in childhood is associated with endotoxinaemia and significantly raised levels of circulating inflammatory cytokines. Plasma CRP at diagnosis showed a statistically significant positive correlation with disease severity.

Plasma amylin concentration is related to the severity of intestinal ischemic injury in rats

BACKGROUND

Previous work has demonstrated that intestinal ischemia increases plasma amylin concentration. This study examined the relationship between the degree of intestinal ischemia injury and plasma amylin in an experimental rat model.

METHODS

Wistar rats were divided into a control group (n = 6); a sham-operated group (n = 9); and 3 intestinal ischemia-reperfusion groups (n = 8 in each), which underwent clamping of the superior mesenteric artery for either 15, 30, or 45 minutes followed by 15 minutes of reperfusion. Samples were then collected for intestinal histology and measurement of amylin, insulin, and glucose.

RESULTS

There was a positive correlation between the histologic score of the intestinal injury and the measured plasma amylin concentration (R = 0.48, P =.007). The median plasma concentration of amylin was 62 pmol/L (range, 42-97 pmol/L) in the 30-minute intestinal ischemia group and 58 pmol/L (42-86 pmol/L) in the 45-minute intestinal ischemia group. Both these groups were increased compared with the sham-operated group (29 pmol/L; range, 22-57 pmol/L; P <.001 and P <.005, respectively) and the control group (28 pmol/L; range, 26-42 pmol/L; P <.001 and P <.0005, respectively). The median plasma concentration of insulin in the 30-minute intestinal ischemia group was 4230 pmol/L (range, 1360-5770 pmol/L), which was increased compared with both the control group (950 pmol/L; range, 550-1510 pmol/L; P <.005) and the sham-operated group (720 pmol/L; range, 280-4180 pmol/L; P<.005). There were no differences between any of the other groups either for glucose, insulin, or amylin.

CONCLUSIONS

Plasma amylin concentration is related to the severity of intestinal ischemic injury.

Evidence against a role for polymorphisms at tumor necrosis factor, interleukin-1 and interleukin-1 receptor antagonist gene loci in the regulation of disease severity in acute pancreatitis

BACKGROUND

Cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) and their endogenous antagonists such as IL-1 receptor antagonist (IL-1RA) are important mediators of disease severity in acute pancreatitis. Because the level of secretion of these cytokines is determined in part by genetic factors, the aim of this study was to examine the influence of genetically determined cytokine secretion upon disease severity in acute pancreatitis.

METHODS

TNF (TNF-308, TNFB), IL-1beta, and IL-1 receptor antagonist (IL-1RA) genotypes were determined for 190 patients with acute pancreatitis and 102 healthy volunteers. To further assess the influence of genetic factors, the cytokine phenotype for TNF-alpha, IL-1beta, and IL-1RA was determined by using a whole blood culture technique in 51 patients after recovery.

RESULTS

The distributions of TNF-308, TNFB, IL-1beta, and IL-1RA gene polymorphisms were similar in patients with mild or severe acute pancreatitis. Further, no difference in gene polymorphism frequencies was observed between patients with acute pancreatitis and healthy controls. With respect to phenotype, the secretion of TNF-alpha was similar in patients with previous mild and severe acute pancreatitis; however, the IL-1beta: IL-1RA ratio was significantly lower in patients with previous severe acute pancreatitis than in those with mild disease.

CONCLUSIONS

Our observations suggest that genetic factors are not important in determining TNF-alpha secretion in patients with acute pancreatitis. However, a predetermined imbalance between IL-1beta and its antagonist IL-1RA would appear to exist in patients with severe acute pancreatitis, although the genetic basis for this altered relationship could not be determined.

Randomized controlled trial of the effect of early enteral nutrition on markers of the inflammatory response in predicted severe acute pancreatitis

BACKGROUND

Recent evidence suggests that intestinal dysfunction has a role in sustaining the systemic inflammatory response in acute pancreatitis and may be ameliorated by the introduction of enteral nutrition. This study therefore assessed the effect of early enteral nutrition on the systemic inflammatory response in patients with prognostically severe acute pancreatitis.

METHODS

Patients with prognostically severe acute pancreatitis within 72 h of disease onset were randomized to receive either enteral nutrition or conventional therapy consisting of a nil-by-mouth regimen. Serum interleukin (IL) 6, soluble tumour necrosis factor receptor I (sTNFRI) and C-reactive protein (CRP) were used as markers of the inflammatory response. Intestinal function was assessed using a differential sugar permeability technique.

RESULTS

Of 27 patients, 13 received enteral nutrition. A median of 21 (range 0-100) per cent of calorific requirements was delivered over the first 4 days by enteral nutrition. There were no significant complications of enteral nutrition. The introduction of enteral nutrition did not affect the serum concentrations of IL-6 (P = 0.28), sTNFRI (P = 0.53) or CRP (P = 0.62) over the first 4 days of the study. Although there were no significant differences in intestinal permeability between the two patient groups at admission (chi2 = 2.33, d.f. = 1, P = 0.13), by day 4 abnormal intestinal permeability occurred more frequently in patients receiving enteral nutrition (chi2 = 4.94, d.f. = 1, P = 0.03)

CONCLUSION

Early enteral nutrition did not ameliorate the inflammatory response in patients with prognostically severe acute pancreatitis. Furthermore, it did not have a beneficial effect on intestinal permeability. Presented in part to the Pancreatic Society of Great Britain and Ireland in Leeds, UK, November 1998 and at Digestive Disease Week in Orlando, Florida, USA, May 1999

Lipopolysaccharide binding protein in acute pancreatitis

OBJECTIVE

To assess the expression of plasma lipopolysaccharide binding protein (LBP) concentrations and its relationship to markers of the systemic inflammatory response syndrome during acute pancreatitis.

DESIGN

A prospective study.

SETTING

General surgical units of university teaching hospitals in the Belfast area.

PATIENTS

The study included 18 patients admitted with established diagnosis of acute pancreatitis on the basis of elevated serum amylase or by contrast radiology. Patients were retrospectively stratified using the Modified Glasgow Criteria into severe (n = 7) and mild (n = 11) disease.

INTERVENTIONS AND MEASUREMENTS

Blood samples were obtained at admission (day 1) and for a further 3 days for the measurement of LBP, C-reactive protein (CRP), tumor necrosis factor, and interleukin (IL)-6. Acute Physiology and Chronic Health Evaluation (APACHE) II scores were calculated on day 1 and day 2.

MAIN RESULTS

LBP and CRP concentrations were significantly increased from healthy control values in acute pancreatitis patients at presentation. In the mild group LBP, CRP and IL-6 concentrations remained relatively constant throughout the study period. By comparison, severe acute pancreatitis was associated with significantly higher LBP concentrations and a marked systemic inflammatory response as evidenced by increased CRP, IL-6, and APACHE II scores. The rise in LBP occurred after the observed increase of these markers. Significant correlations were found among CRP and LBP, IL-6 and LBP, and IL-6 and APACHE II scores. There were no fatalities in the mild group, whereas four of the seven patients with severe disease died.

CONCLUSIONS

LBP was significantly raised in patients with severe acute pancreatitis but would seem to be of limited use in predicting disease severity. This acute phase protein may have a role in the progression of systemic complications associated with acute pancreatitis.