Predictive value of nuclear factor kappaB activity and plasma cytokine levels in patients with sepsis

Treatment of Experimental Septic Shock with Microencapsulated Antisense Oligomers to NF-κB

NF-kappaB is an ideal target for inhibition of proinflammatory cytokines. The purpose of this study was to determine if microencapsulated antisense oligomer to NF-kappaB can inhibit proinflammatory cytokine release in response to Escherichia coli endotoxin and bacteria. Microencapsulation takes advantage of the phagocytic function of the macrophage to deliver the oligomer intracellularly and enhance the effect. Albumin microcapsules 1 microm in size were prepared by a nebulization method containing antisense oligomers to NF-kappaB. E. coli endotoxin was incubated in 1 ml aliquots of whole blood. Microencapsulated antisense to NF-kappaB was given, and the inhibition of tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-6, and IL-8 was compared with similar amounts of oligomer in solution. Endotoxic shock was produced in rats using E. coli endotoxin (15 mg/kg). Peritonitis was induced by injecting 10(10) CFU E. coli. Cytokines were measured after simultaneous and delayed (4 h) administration of antisense to NF-kappaB in microcapsules and solution form. TNF was suppressed by 81% in whole blood, 56% in the endotoxic shock model, 89% in the peritonitis model (simultaneous treatment), and 56% in the delayed treatment group. Survival was 70% in the endotoxic shock group, 80% in the simultaneous peritonitis group, and 70% in the delayed treatment group. Microcapsule treatment using antisense to NF-kappaB suppressed TNF and IL-1 levels and mortality significantly better than all solution treatment groups in the whole blood model, endotoxic shock model, and peritonitis model.

A1 adenosine receptor knockout mice exhibit increased mortality, renal dysfunction, and hepatic injury in murine septic peritonitis

Sepsis is a leading cause of multiorgan dysfunction and death in hospitalized patients. Dysregulated inflammatory processes and apoptosis contribute to the pathogenesis of sepsis-induced organ dysfunction and death. A(1) adenosine receptor (A(1)AR) activation reduces inflammation and apoptosis after ischemia-reperfusion injury. Therefore, we questioned whether A(1)AR-mediated reduction of inflammation and apoptosis could improve mortality and organ dysfunction in a murine model of sepsis. A(1)AR knockout mice (A(1) knockout) and their wild-type (A(1) wild-type) littermate controls were subjected to cecal ligation and double puncture (CLP) with a 20-gauge needle. A(1) knockout mice or A(1) wild-type mice treated with 1,3-dipropyl-8-cyclopentylxanthine (a selective A(1)AR antagonist) had a significantly higher mortality rate compared with A(1) wild-type mice following CLP. Mice lacking endogenous A(1)ARs demonstrated significant elevations in plasma creatinine, alanine aminotransferase, aspartate aminotransferase, keratinocyte-derived chemokine, and tumor necrosis factor-alpha 24 h after induction of sepsis compared with wild-type mice. The renal corticomedullary junction from A(1) knockout mice also exhibited increased myeloperoxidase activity, intercellular adhesion molecule-1 protein, and mRNA encoding proinflammatory cytokines compared with renal samples from A(1) wild-type littermate controls. No difference in renal tubular apoptosis was detected between A(1) knockout and A(1) wild-type mice. We conclude that endogenous A(1)AR activation confers a protective effect in mice from septic peritonitis primarily by attenuating the hyperacute inflammatory response in sepsis.

Immunonutrition

PURPOSE OF REVIEW

To outline recent findings on the efficacy of immunonutrients in patients undergoing inflammatory stress due to surgery, infection and cancer.

RECENT FINDINGS

Enteral nutrition is more efficacious and poses lower risks than parenteral nutrition. It reduces infection rates and shortens ICU and hospital length of stay of critically ill patients. Beneficial effects of immunonutrition are most apparent in malnourished patients. Perioperative enteral nutrition is more effective than postoperative nutrition. In Crohn disease similar remission rates are achieved with enteral nutrition as with steroids. Glutamine, omega-3 fatty acids and antioxidants exert beneficial influences in diverse patient populations. L-arginine is an important immunonutrient having both beneficial and adverse effects. The former effect occurs in necrotizing enterocolitis; the latter influence is seen in septic patients. The gut plays a major role in whole body amino acid metabolism, particularly arginine homeostasis. Arginase and nitric oxide synthetase compete for arginine within immune cells and play a pivotal role in clinical outcome during infection. In cancer a range of antioxidants are able to ameliorate immunosuppression. Intravenous lipids may be deleterious due to the pro-inflammatory effects of omega-6 fatty acids. Omega-3 fatty acids are anti-inflammatory and combined with medium chain triglyceride (MCT) and olive oil may provide a more efficacious form of intravenous lipid.

SUMMARY

Immunonutrition is effective in improving outcome in a wide range of patients when applied enterally, particularly in malnourished individuals. Parenteral immunonutrition carries a higher risk but can be efficacious in selected patient groups for whom enteral nutrition is problematic.

NF-κB: a therapeutic target in inflammatory diseases

The transcription factor NF-kappaB has been implicated in the pathogenesis of a variety of both acute and chronic inflammatory diseases. Many agents have shown promise and potential to abrogate NF-kappaB activity in both in vitro and in vivo systems. These include antioxidants, corticosteroids, proteasome inhibitors, arachadonic acid pathway metabolites, salicylates, molecular interventions and cell-permeable peptides. Unfortunately, therapies aimed at blocking its activation have not proven clinically feasible at this time. As the complex signal transduction pathways leading to NF-kappaB activation are further elucidated, more specific inhibitors of NF-kappaB are likely to be identified.

Extremely high interleukin-6 blood levels and outcome in the critically ill are associated with tumor necrosis factor- and interleukin-1-related gene polymorphisms

OBJECTIVE

To determine the allelic frequencies of interleukin (IL)-6-, IL-1-, and tumor necrosis factor-alpha (TNF)-related gene polymorphisms in critically ill patients with extremely high IL-6 blood level and to examine the genetic effects on their clinical courses.

DESIGN

Population-based association study.

SETTING

A general intensive care unit in a university teaching hospital.

PATIENTS

A total of 150 consecutive critically ill patients recruited at admission to the intensive care unit, regardless of diagnosis, and 150 healthy volunteers.

MEASUREMENTS AND MAIN RESULTS

IL-6 blood levels were measured daily with chemiluminescence immunoassay. The IL-6 peak levels were significantly correlated with simultaneously measured TNF (r = .659, p < .0001) and IL-1beta levels (r = .518, p < .0001), respectively. Single nucleotide polymorphism at position -174 and -596 sites of the IL-6 (IL6-174*G/C and IL6-596*G/A), -308 site of the TNF (TNF-308*G/A), and -511 site of the IL-1beta (IL1B-511*C/T) were identified with real-time polymerase chain reaction assay using specific fluorescence-labeled probe. Within the IL-1 receptor antagonist intron 2, a various number of tandem repeat polymorphisms (IL1RN*1-5) were identified after polymerase chain reaction with gel electrophoresis. Allelic frequencies of patients with IL-6 peak levels of > or =10,000 pg/mL (group A) were compared with those of patients with IL-6 peak levels of <10,000 pg/mL (group B). Neither IL6-174*C nor IL6-596*A were recognized in all the subjects; however, group A showed a higher frequency of TNF-308*A (p = .054), IL1B-511*T (p = .013), and non-IL1RN*1 (p = .008) allele compared with group B. TNF-308*A, IL1RN*2 or IL1RN*3 allele carriers of group A showed sustained high IL-6 levels, despite countermeasures against hypercytokinemia, and their survival rate was lower than that of the noncarriers of those high-risk alleles (p = .025).

CONCLUSIONS

TNF-308*A, IL1RN*2, and IL1RN*3 alleles were associated with the prevalence of the extremely high IL-6 blood level in the critically ill, their uncontrollable blood IL-6 kinetics, and outcome.

n-3 fatty acids, inflammation, and immunity--relevance to postsurgical and critically ill patients

Excessive or inappropriate inflammation and immunosuppression are components of the response to surgery, trauma, injury, and infection in some individuals and these can lead, progressively, to sepsis and septic shock. The hyperinflammation is characterized by the production of inflammatory cytokines, arachidonic acid-derived eicosanoids, and other inflammatory mediators, while the immunosuppression is characterized by impairment of antigen presentation and of T helper cell type-1 responses. Long-chain n-3 FA from fish oil decrease the production of inflammatory cytokines and eicosanoids. They act both directly (by replacing arachidonic acid as an eicosanoid substrate and by inhibiting arachidonic acid metabolism) and indirectly (by altering the expression of inflammatory genes through effects on transcription factor activation). Thus, long-chain n-3 FA are potentially useful anti-inflammatory agents and may be of benefit in patients at risk of developing sepsis. As such, an emerging application of n-3 FA is in surgical or critically ill patients where they may be added to parenteral or enteral formulas. Parenteral or enteral nutrition including n-3 FA appears to preserve immune function better than standard formulas and appears to partly prevent some aspects of the inflammatory response. Studies to date are suggestive of clinical benefits from these approaches, especially in postsurgical patients.

Interleukin-6 Infusion Blunts Proinflammatory Cytokine Production Without Causing Systematic Toxicity in a Swine Model of Uncontrolled Hemorrhagic Shock

BACKGROUND

Serum elevations of interleukin-6 (IL-6) correlate with multiple organ dysfunction syndrome and mortality in critically injured trauma patients. Data from rodent models of controlled hemorrhage suggest that recombinant IL-6 (rIL-6) infusion protects tissue at risk for ischemia-reperfusion injury. Exogenous rIL-6 administered during shock appears to abrogate inflammation, providing a protective rather than a deleterious influence. In an examination of this paradox, the current study aimed to determine whether rIL-6 decreases inflammation in a clinically relevant large animal model of uncontrolled hemorrhagic shock, (UHS), and to investigate the mechanism of protection.

METHODS

Swine were randomized to four groups (8 animals in each): (1) sacrifice, (2) sham (splenectomy followed by hemodilution and cooling to 33 degrees C), (3) rIL-6 infusion (sham plus UHS using grade 5 liver injury with packing and resuscitation plus blinded infusion of rIL-6 [10 mcg/kg]), and (4) placebo (UHS plus blinded vehicle). After 4 hours, blood was sampled, estimated blood loss determined, animals sacrificed, and lung harvested for RNA isolation. Quantitative reverse transcriptase-polymerase chain reaction was used to assess granulocyte colony-stimulating factor (G-CSF), IL-6, and tumor necrosis factor-alpha (TNFalpha) messenger ribonucleic acid (mRNA) levels. Serum levels of IL-6 and TNFalpha were measured by enzyme-linked immunoassay (ELISA).

RESULTS

As compared with placebo, IL-6 infusion in UHS did not increase estimated blood loss or white blood cell counts, nor decrease hematocrit or platelet levels. As compared with the sham condition, lung G-CSF mRNA production in UHS plus placebo increased eightfold (*p < 0.05). In contrast, rIL-6 infusion plus UHS blunted G-CSF mRNA levels, which were not significantly higher than sham levels (p = 0.1). Infusion of rIL-6 did not significantly affect endogenous production of either lung IL-6 or mRNA. As determined by ELISA, rIL-6 infusion did not increase final serum levels of IL-6 or TNFalpha over those of sham and placebo conditions.

CONCLUSIONS

Exogenous rIL-6 blunts lung mRNA levels of the proinflammatory cytokine G-CSF. The administration of rIL-6 does not increase the local expression of IL-6 nor TNFalpha mRNA in the lung. Additionally, rIL-6 infusion does not appear to cause systemic toxicity.

Escherichia coli up-regulates proinflammatory cytokine expression in granulocyte/macrophage lineages of CD34 stem cells via p50 homodimeric NF-kappaB

Umbilical cord blood has emerged as an alternative source of haematopoietic CD34+ cells for allogeneic stem cell transplantation. Although bacteraemia induced by Escherichia coli is considered one of the complications of transplantation, expression of proinflammatory cytokines is poorly understood. In this study, we report the altered expression of proinflammatory cytokines in CD34+ cells and their in vitro cultured cells following E. coli infection. CD34+ stem cells and their cultured cells up-regulated expression of proinflammatory cytokines such as interleukin (IL)-1alpha, IL-6, IL-8 and tumour necrosis factor (TNF)-alpha after infection with E. coli. Expression of the proinflammatory cytokines was generated mainly by the granulocyte-macrophage lineages. E. coli infection activated the signals of p50/p50 nuclear factor-kappaB (NF-kappaB) homodimers and IkappaB kinase. Furthermore, inhibition of NF-kappaB activation lowered the up-regulated expression of the proinflammatory cytokines. These results suggest that CD34+ cells and their cultured cells infected with E. coli induce the expression of proinflammatory cytokines via the NF-kappaB pathway.

Therapeutic effect of in vivo transfection of transcription factor decoy to NF-kappaB on septic lung in mice

Nuclear factor-kappaB (NF-kappaB) plays a key role in regulating expression of several genes involved in the pathophysiology of endotoxic shock. We investigated whether in vivo introduction of synthetic double-stranded DNA with high affinity for the NF-kappaB binding site could block expression of genes mediating pulmonary vascular permeation and thereby provide effective therapy for septic lung failure. Endotoxic shock was induced by an intravenous injection of 10 mg/kg Escherichia coli endotoxin in mice. We introduced NF-kappaB decoy oligodeoxynucleotide (ODN) in vivo 1 h after endotoxic shock by using a gene transfer kit. At 10 h, blood samples were collected for measurement of histamine and for blood-gas analysis. Gene and protein expression levels of target molecules were determined by means of Northern and Western blot analyses, respectively. The transpulmonary flux of (125)I-labeled albumin was used as an index of lung vascular permeability. Administration of endotoxin caused marked increases in plasma histamine and gene and protein expressions of histidine decarboxylase, histamine H(1) receptors, and inducible nitric oxide synthase in lung tissues. Elevated lung vascular permeability was also found. Blood-gas analysis showed concurrent decreases in arterial Po(2), Pco(2), and pH. All of these events induced by endotoxin were significantly inhibited by transfection of NF-kappaB decoy ODN but not by its mutated (scrambled) form (used as a control). Our results indicate for the first time the potential usefulness of NF-kappaB decoy ODN for gene therapy of endotoxic shock.

Research: advances in cell biology relevant to critical illness

During the past decade, enormous advances have been made in cell biology. Major advances included the publication of the human genome sequence, the development of proteomics, and DNA microarray technologies and techniques to selectively "silence" genes using short strands of double-stranded RNA. Some areas of great progress that are particularly relevant to critical care medicine include huge improvements in our understanding of the signal transduction pathways involved in the innate immune response and adaptation to hypoxia. Other areas of important progress include improvements in our understanding of how inflammation causes derangements in epithelial structure and function and impairs cellular utilization of oxygen.

Multivariate Analysis of Cytokine Responses Identifies Distinctive Sensitivities to Lipopolysaccharide in Humans

We describe methods to identify high and low responders in a whole-blood assay of lipopolysaccharide-stimulated cytokine responses. Two multivariate measures of the cytokine responses both captured high and low responses for each of the four individual cytokines that were assayed.

Toward resolving the challenges of sepsis diagnosis

Sepsis in the United States has an estimated annual healthcare cost of 16.7 billion dollars and leads to 120,000 deaths. Insufficient development in both medical diagnosis and treatment of sepsis has led to continued growth in reported cases of sepsis over the past two decades with little improvement in mortality statistics. Efforts over the last decade to improve diagnosis have unsuccessfully sought to identify a "magic bullet" proteic biomarker that provides high sensitivity and specificity for infectious inflammation. More recently, genetic methods have made tracking regulation of the genes responsible for these biomarkers possible, giving current research new direction in the search to understand how host immune response combats infection. Despite the breadth of research, inadequate treatment as a result of delayed diagnosis continues to affect approximately one fourth of septic patients. In this report we review past and present diagnostic methods for sepsis and their respective limitations, and discuss the requirements for more timely diagnosis as the next step in curtailing sepsis-related mortality. We also present a proposal toward revision of the current diagnostic paradigm to include real-time immune monitoring.

Epigallocatechin-3-gallate, a green tea-derived polyphenol, inhibits IL-1 beta-dependent proinflammatory signal transduction in cultured respiratory epithelial cells

Polyphenolic components of green tea, such as epigallocatechin-3-gallate (EGCG), have potent anti-inflammatory properties. We previously showed that EGCG inhibits tumor necrosis factor-alpha (TNF-alpha)-mediated activation of the nuclear factor-kappa B (NF-kappa B) pathway, partly through inhibition of I kappa B kinase (IKK). The NF-kappa B pathway may also be activated in response to interleukin-1 beta (IL-1 beta) stimulation through a distinct signal transduction pathway. We therefore hypothesized that EGCG inhibits IL-1 beta-mediated activation of the NF-kappa B pathway. Because the gene expression of interleukin-8 (IL-8), the major human neutrophil chemoattractant, is dependent on activation of NF-kappa B, IL-8 gene expression in human lung epithelial (A549) cells treated with human IL-1 beta was used as a model of IL-1 beta signal transduction. The EGCG markedly inhibited IL-1 beta-mediated IL-1 beta receptor-associated kinase (IRAK) degradation and the signaling events downstream from IRAK degradation: IKK activation, I kappa B alpha degradation, and NF-kappa B activation. In addition, EGCG inhibited phosphorylation of the p65 subunit of NF-kappa B. The functional consequence of this inhibition was evident by inhibition of IL-8 gene expression. Therefore, the green tea polyphenol EGCG is a potent inhibitor of IL-1 beta signal transduction in vitro. The proximal mechanisms of this effect involve inhibition of IRAK-dependent signaling and phosphorylation of p65.

Immune cells: free radicals and antioxidants in sepsis

The excessive production of reactive oxygen species (ROS), associated with inflammation, leads to a condition of oxidative stress. Oxidative stress is a major contributing factor to the high mortality rates associated with several diseases such as endotoxic shock. This condition can be controlled to a certain degree by antioxidant therapies. Immune cells use ROS in order to support their functions and therefore need adequate levels of antioxidant defenses in order to avoid the harmful effect of an excessive production of ROS. This review discusses the toxic effects of endotoxin, paying particular attention to immune function. It continues by analyzing the mechanism to which specific cells of the immune system recognize endotoxin, and the resulting pathways leading to nuclear factor-kappaB activation and proinflammatory gene transcription. We also focus on the involvement of reactive oxygen and nitric oxide (NO) and the protective role of antioxidants. The potential clinical use of antioxidants in the treatment of sepsis and the effects on the redox state of the immune cells are discussed.

Stress-hyperglycemia, insulin and immunomodulation in sepsis

Stress-hyperglycemia and insulin resistance are exceedingly common in critically ill patients, particularly those with sepsis. Multiple pathogenetic mechanisms are responsible for this metabolic syndrome; however, increased release of pro-inflammatory mediators and counter-regulatory hormones may play a pivotal role. Recent data suggests that hyperglycemia may potentiate the pro-inflammatory response while insulin has the opposite effect. Furthermore, emerging evidence suggests that tight glycemic control will improve the outcome of critically ill patients. This paper reviews the pathophysiology of stress hyperglycemia in the critically ill septic patient and outlines a treatment strategy for the management of this disorder.

The effect of N-acetylcysteine on nuclear factor-kappa B activation, interleukin-6, interleukin-8, and intercellular adhesion molecule-1 expression in patients with sepsis

OBJECTIVE

Expression of inflammatory mediators is controlled in part at the transcriptional level via nuclear factor-kappa B. Inhibition of nuclear factor-kappa B activation may be beneficial in critically ill patients. N-acetylcysteine is an antioxidant that inhibits nuclear factor-kappa B activation in vitro. In this pilot study we investigated the effect of N-acetylcysteine on nuclear factor-kappa B activation and circulating cytokine and adhesion molecules in patients with sepsis.

DESIGN

Prospective, randomized, double blind, placebo-controlled pilot trial.

SETTING

Eight-bed intensive care unit in a university teaching hospital.

PATIENTS

Twenty consecutive patients within 12 hrs of fulfilling the consensus criteria for sepsis.

INTERVENTIONS

A bolus of 150 mg/kg N-acetylcysteine in 100 mL of 0.9% saline over 15 mins, then 50 mg/kg in 100 mL of 0.9% saline over 4 hrs as a loading dose, and then a maintenance infusion of 50 mg/kg in 200 mL of 0.9% saline over each 24-hr period for a total of 72 hrs, or an equivalent volume of saline.

MEASUREMENTS AND MAIN RESULTS

Nuclear factor-kappa B activation was measured in mononuclear leukocytes using electrophoretic mobility shift assay, at baseline and 24, 48, 72, and 96 hrs later. Activation decreased significantly in patients treated with N-acetylcysteine (p =.016) but not placebo and was significantly reduced at 72 hrs compared with both preinfusion values (p =.028) and patients receiving placebo (p =.01). Plasma interleukin-6, interleukin-8, and soluble intercellular adhesion molecule-1 concentrations were measured using enzyme immunoassay. Interleukin-6 concentrations were high initially and then decreased in all patients, regardless of whether they received N-acetylcysteine or placebo. Interleukin-8 decreased significantly only in those who received N-acetylcysteine (p =.0081). Soluble intercellular adhesion molecule-1 concentrations remained unchanged in all patients.

CONCLUSIONS

Administration of N-acetylcysteine results in decreased nuclear factor-kappa B activation in patients with sepsis, associated with decreases in interleukin-8 but not interleukin-6 or soluble intercellular adhesion molecule-1. These pilot data suggest that antioxidant therapy with N-acetylcysteine may be useful in blunting the inflammatory response to sepsis. Further studies are warranted.

Peroxisome Proliferator Activator Receptor-γ Ligands, 15-Deoxy-Δ12,14-Prostaglandin J2 and Ciglitazone, Reduce Systemic Inflammation in Polymicrobial Sepsis by Modulation of Signal Transduction Pathways

Peroxisome proliferator activator receptor-gamma (PPARgamma) is a nuclear receptor that controls the expression of several genes involved in metabolic homeostasis. We investigated the role of PPARgamma during the inflammatory response in sepsis by the use of the PPARgamma ligands, 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) and ciglitazone. Polymicrobial sepsis was induced by cecal ligation and puncture in rats and was associated with hypotension, multiple organ failure, and 50% mortality. PPARgamma expression was markedly reduced in lung and thoracic aorta after sepsis. Immunohistochemistry showed positive staining for nitrotyrosine and poly(ADP-ribose) synthetase in thoracic aortas. Plasma levels of TNF-alpha, IL-6, and IL-10 were increased. Elevated activity of myeloperoxidase was found in lung, colon, and liver, indicating a massive infiltration of neutrophils. These events were preceded by degradation of inhibitor kappaBalpha (IkappaBalpha), activation of IkappaB kinase complex, and c-Jun NH(2)-terminal kinase and, subsequently, activation of NF-kappaB and AP-1 in the lung. In vivo treatment with ciglitazone or 15d-PGJ(2) ameliorated hypotension and survival, blunted cytokine production, and reduced neutrophil infiltration in lung, colon, and liver. These beneficial effects of the PPARgamma ligands were associated with the reduction of IkappaB kinase complex and c-Jun NH(2)-terminal kinase activation and the reduction of NF-kappaB and AP-1 DNA binding in the lung. Furthermore, treatment with ciglitazone or 15d-PGJ(2) up-regulated the expression of PPARgamma in lung and thoracic aorta and abolished nitrotyrosine formation and poly(ADP-ribose) expression in aorta. Our data suggest that PPARgamma ligands attenuate the inflammatory response in sepsis through regulation of the NF-kappaB and AP-1 pathways.

N/A

N/A

Suppression of inflammatory cytokine production by carbon monoxide involves the JNK pathway and AP-1

The stress-inducible protein heme oxygenase-1 provides protection against oxidative stress and modulates pro-inflammatory cytokines. As the sepsis syndrome results from the release of pro-inflammatory mediators, we postulated that heme oxygenase-1 and its enzymatic product CO would protect against lethality in a murine model of sepsis. Mice treated with a lethal dose of lipopolysaccharide (LPS) and subsequently exposed to inhaled CO had significantly better survival and lower serum interleukin (IL)-6 and IL-1beta levels than their untreated counterparts. In vitro, mouse macrophages exposed to LPS and CO had significantly attenuated IL-6 production; this effect was concentration-dependent and occurred at a transcriptional level. The same effect was seen with increased endogenous CO production through overexpression of heme oxygenase-1. Mutation within the AP-1-binding site in the IL-6 promoter diminished the effect of CO on promoter activity, and treatment of macrophages with CO decreased AP-1 binding in an electrophoretic mobility shift assay. Electrophoretic mobility supershift assay indicated that the JunB, JunD, and c-Fos components of AP-1 were particularly affected. Upstream of AP-1, CO decreased JNK phosphorylation in murine macrophages and lung endothelial cells. Mice deficient in the JNK pathway had decreased serum levels of IL-6 and IL-1beta in response to LPS compared with control mice, and no effect of CO on these cytokine levels was seen in Jnk1 or Jnk2 genedeleted mice. In summary, these results suggest that CO provides protection in a murine model of sepsis through modulation of inflammatory cytokine production. For the first time, the effect of CO is shown to be mediated via the JNK signaling pathway and the transcription factor AP-1.

Nuclear factor-kappaB and its role in sepsis-associated organ failure

Nuclear factor (NF)-kappaB is involved in regulating the transcription of many of the immunomodulatory mediators involved in the development of sepsis-induced organ failure. Kinase pathways involving p38 and Akt and initiated by engagement of Toll-like receptors modulate transcriptional activity of NF-kappaB, but apparently through different mechanisms. Increased activation of NF-kappaB occurs with sepsis, and greater levels of nuclear accumulation of NF-kappaB are associated with higher rates of mortality and worse clinical outcome. The percentage of apoptotic neutrophils is reduced in sepsis, and inhibition of nuclear translocation of NF-kappaB restores neutrophil apoptosis to baseline levels. In models of sepsis, suppression of NF-kappaB activation decreases acute inflammatory processes and organ dysfunction. Because NF-kappaB occupies a central role in signaling pathways important in sepsis, modulation of NF-kappaB activity may be an appropriate therapeutic target in patients with sepsis.

Early alterations in neutrophil activation are associated with outcome in acute lung injury

Persistent elevations of proinflammatory cytokines in the lungs are associated with increased mortality from acute lung injury (ALI), suggesting that the degree of pulmonary inflammation is an important determinant of clinical course in ALI. The transcriptional regulatory factor nuclear factor-kappaB (NF-kappaB) is involved in modulating the expression of many cytokines and other proinflammatory mediators implicated in the development and progression of ALI. Because neutrophils appear to play a major role in the development of ALI, we examined the relationships between clinical outcome and activation of NF-kappaB in peripheral neutrophils from patients (n = 30) with sepsis-induced ALI. We found that nuclear translocation of NF-kappaB in this setting was dependent on the activation of p38 and Akt kinases. Diminished activation of NF-kappaB or Akt, but not p38, in the early postintubation period was associated with less time on the ventilator and improved survival in critically ill patients with ALI. These results suggest that early alterations in neutrophil activation patterns, particularly involving the ability to accumulate NF-kappaB to the nucleus after relevant stimuli, contribute to subsequent clinical course in ALI.

The two faces of IKK and NF-kappaB inhibition: prevention of systemic inflammation but increased local injury following intestinal ischemia-reperfusion

We studied the role of NF-kappaB in acute inflammation caused by gut ischemia-reperfusion through selective ablation of IkappaB kinase (IKK)-beta, the catalytic subunit of IKK that is essential for NF-kappaB activation. Ablation of IKK-beta in enterocytes prevented the systemic inflammatory response, which culminates in multiple organ dysfunction syndrome (MODS) that is normally triggered by gut ischemia-reperfusion. IKK-beta removal from enterocytes, however, also resulted in severe apoptotic damage to the reperfused intestinal mucosa. These results show the dual function of the NF-kappaB system, which is responsible for both tissue protection and systemic inflammation, and underscore the caution that should be exerted in using NF-kappaB and IKK inhibitors.

Nuclear factor kappa B expression in peripheral blood mononuclear cells of patients with acute pancreatitis

INTRODUCTION

Although many experimental studies have implicated the activation of nuclear factor kappa B (NF-kappaB) as a pivotal step in the pathobiology of acute pancreatitis, no clinical investigations have been reported. AIMTo investigate the expression of NF-kappaB and its characteristics in peripheral blood mononuclear cells (PBMCs) of patient with acute pancreatitis.

METHODOLOGY

Forty-five patients were prospectively enrolled. The expression of NF-kappaB in PBMCs was measured in the patients by electrophoretic mobility shift assay at admission and 14 days after the onset of acute pancreatitis. Twelve healthy individuals were also included as control subjects.

RESULTS

At admission, the PBMCs from patients with acute pancreatitis showed higher levels of NF-kappaB activities than did those from control subjects. In vitro, the lipopolysaccharide (LPS) treatment of the PBMCs from the control subjects and patients with mild pancreatitis induced further activation of the NF-kappaB. The response was significantly reduced in patients with severe pancreatitis. Patients who had persistently high NF-kappaB activities, a reduced response of NF-kappaB to LPS, and a low p50p65:p50p50 ratio after LPS stimulation at 14 days developed serious systemic complications in the later clinical course.

CONCLUSIONS

An alteration of the characteristics of PBMCs occurs in the early phase of acute pancreatitis and may predispose patients to a higher risk of serious systemic complications.

Effect of flavone derivatives on interleukin-1beta (IL-1beta) mRNA expression and IL-1beta protein synthesis in stimulated RAW 264.7 macrophages

It is known that the redox status of cells affects gene expression. Flavones, as natural antioxidants, efficiently modulate this status and may play a role in the regulation of inducible gene expression of inflammatory mediators. This study was designed to investigate the effect of five flavone derivatives variously substituted with hydroxyl groups (chrysin, galangin, kaempferol, quercetin and myricetin) on interleukin-1beta (IL-1beta) gene expression in stimulated RAW 264.7 macrophages. The cells were incubated with tested hydroxyflavones and stimulated with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). Then, the following were estimated: the level of IL-1beta mRNA in these cells and the concentration of IL-1beta protein in cell-culture supernatants and cell lysates. Each of the tested compounds significantly decreased IL-1beta mRNA expression. The most potent inhibitor was chrysin (hydroxyflavone with two hydroxyl groups and a weak antioxidant activity). The effects of galangin and kaempferol were similar. Myricetin (hydroxyflavone with a strong antioxidant activity) significantly decreased the level of IL-1beta mRNA, but it had no effect on the IL-1beta protein synthesis. The results indicated that hydroxyflavones could modulate the IL-1beta gene expression in activated RAW 264.7 macrophages via inhibiting gene transcription. This action seems unlikely to be the result of antioxidant properties of tested compounds.

Circulating inflammatory mediators predict shock and mortality in febrile patients with microbial infection

The host response to microbial infection is associated with the release of inflammatory mediators. We hypothesized that the type and degree of the systemic response as reflected by levels of circulating mediators predict morbidity and mortality, according to the invasiveness of microbial infection. We prospectively studied 133 medical patients with fever and culture-proven microbial infection. For 3 days after inclusion, the circulating levels of activated complement C3a, interleukin (IL)-6, and secretory phospholipase A(2) (sPLA(2)) were determined daily. Based on results of microbiological studies performed for up to 7 days, patients were classified as having local infections (Group 1, n = 80 positive local cultures or specific stains for fungal or tuberculous infections) or bacteremia (Group 2, n = 52 plus 1 patient with malaria parasitemia). Outcome was assessed as the development of septic shock and as mortality up to 28 days after inclusion. Fifteen patients (11%) developed septic shock and overall mortality was 18% (n = 24). Bacteremia was associated with shock and shock predisposed to death. Circulating mediator levels were generally higher in Group 2 than in Group 1. Circulating levels of IL-6 and sPLA(2) were higher in patients developing septic shock and in nonsurvivors, particularly in Group 1. High C3a was particularly associated with nonsurvival in Group 2. In Group 1, the area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the peak sPLA(2) for shock development was 0.79 (P < 0.05). The AUC of the ROC curve of the peak IL-6 and sPLA(2) for mortality was 0.69 and 0.68 (P < 0.05), respectively. In Group 2, the AUC of the ROC for peak C3a predicting mortality was 0.73 (P < 0.05). In conclusion, in medical patients with fever and microbial infection, the systemic inflammatory host response predicts shock and death, at an early stage, dependent on the invasiveness of microbial infection. The results suggest a differential pathogenetic role of complement activation on the one hand and release of cytokine and lipid mediators on the other in bacteremic and local microbial infections, respectively. They may partly explain the failure of strategies blocking proinflammatory cytokines or sPLA(2) in human sepsis and may extend the basis for attempts to inhibit complement activation at an early stage in patients at risk of dying from invasive microbial infections.

Enhanced expression of intranuclear NF-kappa B in primed polymorphonuclear leukocytes in systemic inflammatory response syndrome patients

BACKGROUND

Nuclear factor-kappa B (NF-kappa B) plays a critical role in the cellular response to a variety of stimuli, and it regulates the production of various inflammatory cytokines, adhesion molecules, and enzymes. Polymorphonuclear leukocytes (PMNLs) play a central role in systemic inflammatory response after severe insult. The role of NF-kappa B in activation of PMNLs, however, has not been clear. We developed a simple flow cytometric method for quantifying expression of intranuclear NF-kappa B in PMNLs, and we used it to evaluate NF-kappa B activity in patients with systemic inflammatory response syndrome (SIRS).

METHODS

Thirty patients who fulfilled the criteria for SIRS and 24 healthy volunteers were included as study subjects. Expression of intranuclear NF-kappa B with and without stimulation by lipopolysaccharide was quantified by our new method. Oxidative activity in PMNLs with and without formylmethionyl-leucyl-phenylalanine stimulation was measured by flow cytometry. Levels of interleukin-6, interleukin-8, PMNL elastase, and nitric oxide metabolites in blood were also measured.

RESULTS

Expression of intranuclear NF-kappa B in PMNLs both with and without LPS stimulation was significantly elevated in SIRS patients in comparison with that of healthy volunteers. PMNL oxidative activity was significantly elevated in SIRS patients. Positive correlation was observed between intranuclear NF-kappa B expression and PMNL oxidative activity, whereas no relation was observed between intranuclear NF-kappa B expression and serum concentrations of chemical mediators.

CONCLUSION

Our new flow cytometric method proved useful for quantifying intranuclear NF-kappa B expression in PMNLs. In PMNLs from SIRS patients, intranuclear NF-kappa B expression and oxidative activity were significantly elevated with positive correlation, and enhanced expression of NF-kappa B may play an important role in PMNL activation in SIRS.

Oxidative stress and gene expression in sepsis

Dysregulation of the immuno-inflammatory response, as seen in sepsis, may culminate in host cell and organ damage. Lipopolysaccharide from Gram-negative bacterial cell walls induces gene activation and subsequent inflammatory mediator expression. Gene activation is regulated by a number of transcription factors at the nuclear level, of which nuclear factor kappaB appears to have a central role. The redox (reduction-oxidation) cellular balance is important for normal cellular function, including transcription factor regulation. In sepsis, a state of severe oxidative stress is encountered, with host endogenous antioxidant defences overcome. This has implications for cellular function and the regulation of gene expression. This review gives an overview of the mechanisms by which transcription factor activation and inflammatory mediator overexpression occur in sepsis, together with the events surrounding the state of oxidative stress encountered and the effects on the host's antioxidant defences. The effect of oxidative stress on transcription factor regulation is considered, together with the role of antioxidant repletion in transcription factor activation and in sepsis in general. Other interventions that may modulate transcription factor activation are also highlighted.

N-3 polyunsaturated fatty acids and inflammation: from molecular biology to the clinic

The immune system is involved in host defense against infectious agents, tumor cells, and environmental insults. Inflammation is an important component of the early immunologic response. Inappropriate or dysfunctional immune responses underlie acute and chronic inflammatory diseases. The n-6 PUFA arachidonic acid (AA) is the precursor of prostaglandins, leukotrienes, and related compounds that have important roles in inflammation and in the regulation of immunity. Feeding fish oil results in partial replacement of AA in cell membranes by EPA. This leads to decreased production of AA-derived mediators, through several mechanisms, including decreased availability of AA, competition for cyclooxygenase (COX) and lipoxygenase (LOX) enzymes, and decreased expression of COX-2 and 5-LOX. This alone is a potentially beneficial anti-inflammatory effect of n-3 FA. However, n-3 FA have a number of other effects that might occur downstream of altered eicosanoid production or might be independent of this effect. For example, dietary fish oil results in suppressed production of proinflammatory cytokines and can modulate adhesion molecule expression. These effects occur at the level of altered gene expression. Fish oil feeding has been shown to ameliorate the symptoms of some animal models of autoimmune disease and to protect against the effects of endotoxin. Clinical studies have reported that oral fish oil supplementation has beneficial effects in rheumatoid arthritis and among some asthmatics, supporting the idea that the n-3 FA in fish oil are anti-inflammatory. There are indications that the inclusion of fish oil in enteral and parenteral formulae is beneficial to patients.

Role of NF-kB in multiple organ dysfunction during acute obstructive cholangitis

AIM

To elucidate the role of NF-kB activation in the development of multiple organ dysfunction (MOD) during acute obstructive cholangitis (AOC) in rats.

METHODS

Forty-two Wistar rats were divided into three groups: the AOC group, the group of bile duct ligation (BDL group), and the sham operation group (SO group). All the animals in the three groups were killed in the 6th and 48th hour after operation. Morphological changes of vital organs were observed under light and electron microscopy. NF-kB activation was determined with Electrophoretic Mobility Shift Assay (EMSA). Arterial blood gas analyses and the serum levels of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine were performed. The concentrations of TNF-alpha and IL-6 in plasma were also measured.

RESULTS

The significant changes of histology and ultrastructure of vital organs were observed in AOC group. By contrast, in BDL group, all the features of organs damage were greatly reduced. Expression of NF-kB activation in various tissues increased in AOC group when compared to other two groups. At 6 h, the arterial pH in three groups was 7.52+/-0.01, 7.46+/-0.02, and 7.45+/-0.02, and the blood pCO(2) was 33.9+/-0.95 mmHg, 38.1+/-0.89 mmHg, 38.9+/-0.94 mmHg, there was difference in three groups (P<0.05). At 48 h, the blood pH values in three groups was 7.33+/-0.07, 7.67+/-0.04, and 7.46+/-0.03, and blood HCO(3)(-) was 20.1+/-1.29 mmol x L(-1), 26.7+/-1.45 mmol x L(-1) and 27.4+/-0.35 mmol x L(-1), there was also difference in three groups (P<0.05). In AOC group, Levels of LDH, ALT, BUN and creatinine were 1,6359.9+/-2,278.8 nkat x L(-1), 5,796.2+/-941.9 nkat.L(-1), 55.7+/-15.3 mg/dl, and 0.72+/-0.06 mg/dl, which were higher than in SO group (3,739.1+/- 570.1 nkat x L(-1), 288.4+/-71.7 nkat x L(-1), 12.5+/-2.14 mg/dl, and 0.47+/-0.03 mg/dl) (P<0.05). Levels of plasma TNF-alpha and IL-6 in AOC at 48 h were 429+/-56.62 ng x L(-1) and 562+/-57 ng x L(-1), which increased greatly when compared to BDL group (139+/-16 ng x L(-1), 227+/-43 ng x L(-1)) and SO group (74+/-10 ng x L(-1), 113+/-19 ng x L(-1)) (P<0.05).

CONCLUSION

The pathological damages and the NF-kB activation of many vital organs excised during AOC. These findings have an important implication for the role of NF-kB activation in MOD during AOC.

Dietary modification of inflammation with lipids

The n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are found in high proportions in oily fish and fish oils. The n-3 PUFA are structurally and functionally distinct from the n-6 PUFA. Typically, human inflammatory cells contain high proportions of the n-6 PUFA arachidonic acid and low proportions of n-3 PUFA. The significance of this difference is that arachidonic acid is the precursor of 2-series prostaglandins and 4-series leukotrienes, which are highly-active mediators of inflammation. Feeding fish oil results in partial replacement of arachidonic acid in inflammatory cell membranes by EPA. This change leads to decreased production of arachidonic acid-derived mediators. This response alone is a potentially beneficial anti-inflammatory effect of n-3 PUFA. However, n-3 PUFA have a number of other effects which might occur downstream of altered eicosanoid production or might be independent of this activity. For example, animal and human studies have shown that dietary fish oil results in suppressed production of pro-inflammatory cytokines and can decrease adhesion molecule expression. These effects occur at the level of altered gene expression. This action might come about through antagonism of the effects of arachidonic acid-derived mediators or through more direct actions on the intracellular signalling pathways which lead to activation of transcription factors such as nuclear factor kappa B (NFB). Recent studies have shown that n-3 PUFA can down regulate the activity of the nuclear transcription factor NFB. Fish oil feeding has been shown to ameliorate the symptoms in some animal models of chronic inflammatory disease and to protect against the effects of endotoxin and similar inflammatory challenges. Clinical studies have reported that oral fish oil supplementation has beneficial effects in rheumatoid arthritis and among some patients with asthma, supporting the idea that the n-3 PUFA in fish oil are anti-inflammatory. There are indications that inclusion of n-3 PUFA in enteral and parenteral formulas might be beneficial to patients in intensive care or post-surgery.

In vitro effects of eicosanoids derived from different 20-carbon Fatty acids on production of monocyte-derived cytokines in human whole blood cultures

INTRODUCTION

Prostaglandins (PG) and leukotrienes (LT) are usually formed from arachidonic acid (e.g. PGE(2), LTB(4), LTC(4)). The anti-inflammatory effects of fish oil may be mediated through the production of alternative PG and/or LT formed from eicosapentaenoic acid (e.g. PGE(3), LTC(5)). This study examines the effects of PG and LT derived from different fatty acid precursors on lipopolysaccharide-induced cytokine production by cultured human whole blood. Methods Human whole blood was diluted 1:5 and incubated for 48h with lipopolysaccharide. PGE and LT were added and the concentrations of inflammatory cytokines in the cell culture supernatants determined.

RESULTS

Tumour necrosis factor (TNF)-alpha concentrations were significantly decreased by the addition of PGE. At the maximum concentration used (10(-6)M) TNF-alpha concentration was reduced to 100%, 90% and 70% by PGE(1), PGE(2) and PGE(3) respectively. Likewise, interleukin (IL)-1beta concentration was decreased to 60%, 30% and 40% by 10(-6)M PGE(1), PGE(2) and PGE(3), respectively. IL-6 and IL-10 concentrations were not altered by PG. LTB(4), LTC(4) or LTC(5) did not significantly affect cytokine concentrations.

CONCLUSIONS

PGE inhibit lipopolysaccharide-stimulated TNF-alpha and IL-1beta production in human whole blood cultures. PGE(1), PGE(2) and PGE(3) show a similar pattern and magnitude of effect. This suggests that the anti-inflammatory effects of dietary fish oil may not be mediated through a simple substitution of one family of eicosanoids for another.

Insight into some of the signaling pathways triggered by a lipid immunomodulator

The use of non specific immunomodulatory agents takes an important place in the aspecific host response to invading microorganisms. In this context, antimicrobial properties of royal jelly have been ascribed to organic acids (mainly 10 hydroxy-2-decenoic acid or 10-HDA) and proteins. We synthesized a derivative of 10-HDA, the 1-(2-methoxyethoxymethyl)2,3-(10-hydroxy2-decenoyl)(E) glycerol referred as diHDA-glycerol which was previously found to protect mice against virulent Salmonella typhimurium challenge through more adequate immune regulations. This study was conducted to further investigate some of the signaling pathways followed by diHDA-glycerol in cell transduction. Members of NF-kappaB transcription factors are key regulators of many cytokines acting on immunity and they control genes involved in responses to numerous signals such as bacterial products. Therefore, we investigated some parameters acting on NF-kappaB translocation in U937 cells after diHDA-glycerol treatment. Due to the chemical structure of the molecule we also investigated the sphingomyelinase pathway. Our results showed that diHDA-glycerol induced a rapid NF-kappaB translocation as a consequence of IkappaB-alpha proteolysis. An intracellular production of reactive oxygen species (ROS) may also account for NF-kappaB activation, without de novo protein synthesis. DiHDA-glycerol induced a strong activation of neutral sphingomyelinase, suggesting an important role of sphingolipids in the regulatory responses induced by diHDA-glycerol.

Stress-dose corticosteroid therapy for sepsis and acute lung injury or acute respiratory distress syndrome in critically ill adults

Sepsis and acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) are associated with high mortality rates despite recent therapeutic advances. Both disease states involve uncontrolled host defense responses that lead to inflammation, endothelial damage, enhanced coagulation, diminished fibrinolysis and fibroproliferation to produce microthrombi, and relative adrenal insufficiency. Corticosteroids inhibit the host defense response and may offer an inexpensive therapeutic option. Results of several randomized, double-blind studies demonstrated no survival benefit and higher secondary infection rates when supraphysiologic doses of corticosteroids were administered for less than 24 hours. Recently, the emphasis of research for corticosteroid therapy has involved adrenocortical replacement dosage regimens administered for several days to weeks, with doses corresponding to the stress level of the disease. Stress-dose therapy with hydrocortisone in patients with septic shock who require vasopressor support, especially if adrenal insufficiency is present, accelerates hemodynamic stability and reduces mortality. The frequency of gastrointestinal hemorrhage was higher with corticosteroid therapy than with placebo, but the occurrence of secondary infections was similar to that of placebo. The only randomized, double-blind study that evaluated stress-dose methylprednisolone therapy for ARDS was terminated early after only 24 patients were enrolled because therapy with methylprednisolone was associated with enhanced survival despite higher secondary infection rates. A multicenter study investigating stress-dose methylprednisolone for ARDS is under way and should provide valuable information. Sufficient data support stress-dose hydrocortisone therapy for vasopressor-dependent septic shock. Stress-dose methylprednisolone therapy for ALI-ARDS requires further study but may be warranted in cases of refractory infection-induced ARDS when impending mortality is likely.

Parthenolide, an inhibitor of the nuclear factor-kappaB pathway, ameliorates cardiovascular derangement and outcome in endotoxic shock in rodents

Parthenolide is a sesquiterpene lactone used in folk medicine for its anti-inflammatory activity. Recent in vitro studies have shown that this compound inhibits the nuclear factor (NF)-kappaB pathway. This study examines the effect of parthenolide in endotoxic shock in rodents. Endotoxic shock was induced by administration of Escherichia coli endotoxin in rats. Three groups of rats received parthenolide (0.25, 0.5, or 1 mg/kg) 15 min before endotoxin; another group received parthenolide (1 mg/kg) 3 h after endotoxin. In vehicle-treated rats, administration of endotoxin caused severe hypotension, which was associated with a marked hyporeactivity to norepinephrine in ex vivo thoracic aortas. Immunohistochemistry showed positive staining for nitrotyrosine, poly(ADP-ribose) synthetase (PARS) and apoptosis, whereas Northern blot analysis showed increased mRNA expression of inducible nitric-oxide synthase (iNOS) in thoracic aortas. Elevated levels of plasma nitrate/nitrite were also found. Elevated lung levels of myeloperoxidase activity were indicative of infiltration of neutrophils. These inflammatory events were preceded by cytosolic degradation of inhibitor kappaBalpha (IkappaBalpha) and activation of nuclear NF-kappaB in the lung. In vivo pretreatment and post-treatment with parthenolide improved the hemodynamic profile and reduced plasma nitrate/nitrite and lung neutrophil infiltration in a dose-dependent fashion. Vascular hyporeactivity of ex vivo aortas was ameliorated. Treatment with parthenolide also abolished nitrotyrosine formation, PARS expression, and apoptosis and reduced iNOS mRNA content in thoracic aortas. DNA binding of NF-kappaB was inhibited by parthenolide in the lung, whereas degradation of IkappaBalpha was unchanged. In a separate set of experiments, pretreatment or post-treatment with parthenolide significantly improved survival in mice challenged with endotoxin. We conclude that parthenolide exerts beneficial effects during endotoxic shock through inhibition of NF-kappaB.

Nuclear factor kB activity in patients with acute severe cholangitis

AIM

To determine the NF-kB activity in peripheral blood mononuclear cells (PBMC) in patients with acute cholangitis of severe type (ACST) and correlate the degree of NF-kB activation with severity of biliary tract infection and clinical outcome.

METHODS

Twenty patients with ACST were divided into survivor group (13 cases) and nonsurvivor group (7 cases). Other ten patients undergoing elective gastrectomy or inguinal hernia repair were selected as control group. Peripheral blood samples were taken 24 hours postoperatively. PBMC were separated by density gradient centrifugation, then nuclear proteins were isolated from PBMC, and Electrophoretic Mobility Shift Assay (EMSA) used determined. The results were quantified by scanning densitometer of a Bio-Image Analysis System and expressed as relative optical density (ROD). The levels of TNF-alpha, IL-6, and IL-10 in the plasma of patients with ACST and healthy control subjects were determined by using an enzyme-linked immunoassay (ELISA).

RESULTS

The NF-kB activity was 5.02 +/- 1.03 in nonsurvivor group, 2.98 +/- 0.51 in survivor group and 1.06 +/- 0.34 in control group. There were statistical differences in three groups (P<0.05). The levels of TNF-alpha and IL-6 in plasma were (498 +/- 53)ng.L(-1)and (587 +/- 64)ng.L(-1)in nonsurvivor group, (284 +/- 32)ng.L(-1) and (318 +/- 49)ng.L(-1)in survivor group and (89 +/- 11)ng.L(-1) and (102 +/-13)ng.L(-1)in control group. All patients with ACST had increased levels of TNF-alpha and IL-6, which were many-fold greater than those of control group, and there was an evidence of significantly higher levels in those of nonsurvivor group than that in survivor group (P<0.05). The levels of IL-10 in plasma were (378+/-32)ng.L(-1), (384+/-37)ng.L(-1) and (68+/-11)ng.L(-1) in three groups, respectively. All patients had also increased levels of IL-10 when compared with control group (P<0.05), but the IL-10 levels were not significantly higher in nonsurvivors than in survivors (P>0.05).

CONCLUSION

NF-kB activity in PBMC in patients with ACST increases markedly and the degree of NF-kB activation is correlated with severity of biliary tract infection and clinical outcome.

Interleukin-1 receptor antagonist gene polymorphism and mortality in patients with severe sepsis

This study aims to determine the influence of the polymorphism within the intron 2 of the interleukin-1 receptor antagonist gene (IL-1RN*) on the outcome of severe sepsis, and to assess its functional significance by correlating this polymorphism with the total production of interleukin-1 receptor antagonist (IL-1Ra) protein determined in stimulated peripheral blood mononuclear cells (PBMC). A group of 78 patients with severe sepsis (51 survivors and 27 nonsurvivors) was compared with a healthy control group of 130 blood donors, and 56 patients with uncomplicated pneumonia. We found a significant association between IL-1RN* polymorphism and survival. Thus, after adjusting for age and APACHE II score, multiple logistic regression analysis showed that patients homozygotes for the allele *2 had a 6.47-fold increased risk of death (95% CI 1.01--41.47, P = 0.04). Besides, compared with patients homozygous or heterozygous for the allele *1, IL-1RN*2 homozygotes produced significantly lower levels of IL-1Ra from their PBMC. Our results suggest that insufficient production of this cytokine might contribute, among other factors, to the higher mortality rate found in severe sepsis patients with the IL-1RN*2 homozygous genotype.

Humoral markers of severity and prognosis of critical illness

Despite the considerable advances made in understanding the pathophysiology of systemic inflammation during critical illness, clinical progress has been elusive as it remains a very deadly condition. Cortisol and thyroid hormone levels can be as predictive of outcome as the commonly used severity parameters (i.e. APACHE). Indeed, levels of endocrine humoral substances such as arachidonic acids, nitric oxide, endothelin, calcitonin precursors, leptin and adenosine correlate with the severity and outcome of critical illness. Furthermore, calcitonin precursors represent a potentially new hormokine paradigm, being transcriptionally activated in all cells in response to infection. The cytokines are immune markers that often correlate with severity and outcome, but their release is transient. In contrast, the so-called acute phase proteins, such as C-reactive protein and serum amyloid A, are highly sensitive to inflammatory activity and can be important markers of severity and outcome. Leukocyte esterase, adhesion molecules, platelet activating factor and activated protein C are additional humoral immune markers; the replacement of the latter has been shown to be a promising therapeutic option. Natriuretic peptides are neurocrine humoral markers that have important cardiovascular implications. The level of macrophage migrating inhibitory factor, released by the pituitary, is elevated in sepsis and counteracts glucocorticoid action. Cellular markers to severe stress include the enhanced expression of protective substances in the form of heat shock proteins. High mobility group-1 is a DNA-binding protein and a late mediator of the inflammatory response. Apoptotic markers such as the soluble fas ligand are also elevated in inflammation. In summary, during critical illness, the endocrine, immune and nervous systems elaborate a multitude of humoral markers, the roles of which merit further scrutiny in order to improve therapeutic outcome.

Intracellular glutathione deficiency is associated with enhanced nuclear factor-kappaB activation in older non-insulin dependent diabetic patients

Diabetes mellitus may be associated with intracellular glutathione (GSH) deficiency. Since in vivo studies have shown that plasma intracellular GSH plays a key role in regulating the activation of nuclear factor kappaB (NF-kappaB), we have investigated the relationship between intracellular thiols (GSH, homocysteine, cysteine and cysteinyglycine) and NF-kappaB activity in the peripheral blood mononuclear cells (PBMC) of 63 elderly non-insulin dependent diabetes mellitus (NIDDM) patients (28 microalbuminurics and 35 normoalbuminurics) and 30 healthy age- and sex-matched subjects. In addition, we have measured plasma concentrations of these thiol compounds, serum concentrations of interleukin-6 (IL-6) and vascular cell adhesion molecule-1 (sVCAM-1), that are partly dependent on the NF-kappaB activation, as well as the serum levels of thiobarbituric acid reacting substances (TBARS), as index of lipid peroxidation. Diabetic patients with microalbuminuria (MAB) and normoalbuminuria had NF-kappaB activity 2.1- and 1.5-fold greater, respectively, than the control group. As compared to normoalbuminuric patients, patients with MAB had significantly higher levels of glycemia, plasma homocysteine, and serum concentrations of TBARS, IL-6 and sVCAM-1 (in all cases, p < 0.01), and significantly lower GSH content in the PBMC (p < 0.05). The intracellular GSH in PBMC correlated with NF-kappaB activation (r = -0.82; p < 0.0001), serum TBARS (r = -0.60; p < 0.001), and with fasting glycemia (r = -0.56; p < 0.001) in patients with MAB, whereas a weaker association between GSH levels in PBMC and NF-kappaB activation (r = -0.504, p < 0.001) was seen in patients without MAB. These results suggest that the decrease of intracellular GSH content in elderly NIDDM patients with MAB is strongly associated with enhanced NF-kappaB activation, which could contribute to the development of increased glomerular capillary permeability and its rapid progression.

Nutritional modulation of immune function

The inflammatory response to injury and infection, although an essential part of immune function, carries the risk of severe tissue depletion and immunosuppression. These outcomes increase morbidity and delay recovery. Evidence is accumulating that single-nucleotide polymorphisms in the genes controlling pro-inflammatory cytokine production adversely influence the response. Immunonutrition provides a means of modulating the inflammatory response to injury and infection, and thereby improves clinical outcome. n-3 Polyunsaturated fatty acids (n-3 PUFA), glutamine, arginine, S amino acids and nucleotides are important components of immunonutrient mixes. While animal model studies suggest that all these components may exert a beneficial effect in patients, the number of large randomized placebo-controlled trials utilizing immunonutrition is fairly limited and the observed effects are relatively small. Meta-analyses suggest that while immunonutrition may not reduce mortality rates, a reduction in hospital length of stay, decreased requirements for ventilation and lower infection rates are achieved by this mode of nutrition. The present paper discusses some underlying reasons for the difficulty in demonstrating the clinical efficacy of immunonutrition. Paramount among these reasons is the antioxidant status and genetic background of the patient. A number of studies suggest that there is an inverse relationship between inflammation and T-cell function. Immuno-enhancive effects have been shown in a number of studies in which n-3 PUFA, glutamine and N-acetyl cysteine have been employed. All these nutrients may exert their effects by suppressing inflammation; n-3 PUFA by direct suppression of the process and glutamine and N-acetyl cysteine by acting indirectly on antioxidant status. Glutamine and nucleotides exert a direct effect on lymphocyte proliferation. Preliminary data suggests that not all genotypes are equally sensitive to the effects of immunonutrition. When further studies have been conducted to discern the precise interaction between each individual's genotype of relevance to the response to injury and infection, and immunonutrients, the level of precision in the application of immunonutrition will undoubtedly improve.