CDP571, a humanized antibody to human tumor necrosis factor-alpha: safety, pharmacokinetics, immune response, and influence of the antibody on cytokine concentrations in patients with septic shock. CPD571 Sepsis Study Group

The Prospect of Biomimetic Immune Cell Membrane-Coated Nanomedicines for Treatment of Serious Bacterial Infections and Sepsis

Invasive bacterial infections and sepsis are persistent global health concerns, complicated further by the escalating threat of antibiotic resistance. Over the past 40 years, collaborative endeavors to improve the diagnosis and critical care of septic patients have improved outcomes, yet grappling with the intricate immune dysfunction underlying the septic condition remains a formidable challenge. Anti-inflammatory interventions that exhibited promise in murine models failed to manifest consistent survival benefits in clinical studies through recent decades. Novel therapeutic approaches that target bacterial virulence factors, for example with monoclonal antibodies, aim to thwart pathogen-driven damage and restore an advantage to the immune system. A pioneering technology addressing this challenge is biomimetic nanoparticles-a therapeutic platform featuring nanoscale particles enveloped in natural cell membranes. Borne from the quest for a durable drug delivery system, the original red blood cell-coated nanoparticles showcased a broad capacity to absorb bacterial and environmental toxins from serum. Tailoring the membrane coating to immune cell sources imparts unique characteristics to the nanoparticles suitable for broader application in infectious disease. Their capacity to bind both inflammatory signals and virulence factors assembles the most promising sepsis therapies into a singular, pathogen-agnostic therapeutic. This review explores the ongoing work on immune cell-coated nanoparticle therapeutics for infection and sepsis. SIGNIFICANCE STATEMENT: Invasive bacterial infections and sepsis are a major global health problem made worse by expanding antibiotic resistance, meaning better treatment options are urgently needed. Biomimetic cell-membrane-coated nanoparticles are an innovative therapeutic platform that deploys a multifaceted mechanism to action to neutralize microbial virulence factors, capture endotoxins, and bind excessive host proinflammatory cytokines, seeking to reduce host tissue injury, aid in microbial clearance, and improve patient outcomes.

The Potential Diagnostic and Predictive Role of HbA1c in Diabetic, Septic Patients: A Retrospective Single-Center Study

Background

As diabetes mellitus is a major risk factor of sepsis, we aimed to evaluate the possible effects of diabetes mellitus and poor glycemic control on the diagnosis of sepsis.

Methods

In our retrospective study, we included diabetic, septic patients-in whom the diagnosis of sepsis was based on the systemic inflammatory response syndrome (SIRS) criteria (n = 112, SIRS group)-who had HbA1c levels measured either in the previous 30 days (n = 39, SIRS 30 d subgroup) or within 24 hours after their emergency department admission (n = 73, SIRS 24 h subgroup). We later selected those patients from the SIRS group, whose sequential organ failure assessment (SOFA) score was ≥2 (n = 55, SOFA group), and these patients were also divided based on the time of HbA1c measurement (n = 21, SOFA 30 d subgroup and n = 34, SOFA 24 h subgroup). We analyzed the relationship between laboratory parameters, length of hospital stay, and HbA1c.

Results

We found a significant positive correlation between glucose and HbA1c (p < 0.001, p < 0.001, respectively), significant negative correlations between white blood cell count (WBC) and glucose (p=0.01, p=0.02, respectively), WBC and HbA1c levels (p=0.001, p=0.02, respectively) in the SIRS 24 h and SOFA 24 h subgroups. Furthermore, there was a significant positive correlation between length of hospital stay and HbA1c in the SOFA 24 h subgroup (p=0.01). No significant correlations were found in the SIRS 30 d and SOFA 30 d subgroups.

Conclusion

Based on our results, normal WBC with elevated HbA1c might be considered a positive SIRS criterium in diabetic, SIRS 24 h patients. Besides this potential diagnostic role, HbA1c might also be an additional prognostic biomarker in diabetic, SOFA 24 h patients.

Dichotomous Role of Tumor Necrosis Factor in Pulmonary Barrier Function and Alveolar Fluid Clearance

Alveolar-capillary leak is a hallmark of the acute respiratory distress syndrome (ARDS), a potentially lethal complication of severe sepsis, trauma and pneumonia, including COVID-19. Apart from barrier dysfunction, ARDS is characterized by hyper-inflammation and impaired alveolar fluid clearance (AFC), which foster the development of pulmonary permeability edema and hamper gas exchange. Tumor Necrosis Factor (TNF) is an evolutionarily conserved pleiotropic cytokine, involved in host immune defense against pathogens and cancer. TNF exists in both membrane-bound and soluble form and its mainly -but not exclusively- pro-inflammatory and cytolytic actions are mediated by partially overlapping TNFR1 and TNFR2 binding sites situated at the interface between neighboring subunits in the homo-trimer. Whereas TNFR1 signaling can mediate hyper-inflammation and impaired barrier function and AFC in the lungs, ligand stimulation of TNFR2 can protect from ventilation-induced lung injury. Spatially distinct from the TNFR binding sites, TNF harbors within its structure a lectin-like domain that rather protects lung function in ARDS. The lectin-like domain of TNF -mimicked by the 17 residue TIP peptide- represents a physiological mediator of alveolar-capillary barrier protection. and increases AFC in both hydrostatic and permeability pulmonary edema animal models. The TIP peptide directly activates the epithelial sodium channel (ENaC) -a key mediator of fluid and blood pressure control- upon binding to its α subunit, which is also a part of the non-selective cation channel (NSC). Activity of the lectin-like domain of TNF is preserved in complexes between TNF and its soluble TNFRs and can be physiologically relevant in pneumonia. Antibody- and soluble TNFR-based therapeutic strategies show considerable success in diseases such as rheumatoid arthritis, psoriasis and inflammatory bowel disease, but their chronic use can increase susceptibility to infection. Since the lectin-like domain of TNF does not interfere with TNF's anti-bacterial actions, while exerting protective actions in the alveolar-capillary compartments, it is currently evaluated in clinical trials in ARDS and COVID-19. A more comprehensive knowledge of the precise role of the TNFR binding sites versus the lectin-like domain of TNF in lung injury, tissue hypoxia, repair and remodeling may foster the development of novel therapeutics for ARDS.

Baricitinib: A Review of Pharmacology, Safety, and Emerging Clinical Experience in COVID-19

A hyperinflammatory response to severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection, reminiscent of cytokine release syndrome, has been implicated in the pathophysiology of acute respiratory distress syndrome and organ damage in patients with coronavirus disease 2019 (COVID-19). Agents that inhibit components of the pro-inflammatory cascade have garnered interest as potential treatment options with hopes that dampening the proinflammatory process may improve clinical outcomes. Baricitinib is a reversible Janus-associated kinase (JAK)-inhibitor that interrupts the signaling of multiple cytokines implicated in COVID-19 immunopathology. It may also have antiviral effects by targeting host factors that viruses rely for cell entry and by suppressing type I interferon driven angiotensin-converting-enzyme-2 upregulation. However, baricitinib's immunosuppressive effects may be detrimental during acute viral infections by delaying viral clearance and increasing vulnerability to secondary opportunistic infections. The lack of reliable biomarkers to monitor patients' immune status as illness evolves complicates deployment of immunosuppressive drugs like baricitinib. Furthermore, baricitinib carries the risk of increased thromboembolic events, which is concerning given the proclivity towards a hypercoagulable state in patients with COVID-19. In this article, we review available data on baricitinib with an emphasis on immunosuppressive and antiviral pharmacology, pharmacokinetics, safety, and current progress in COVID-19 clinical trials.

Role of Immunoglobulin Therapy to Prevent and Treat Infections

Immunoglobulins have been used widely in medicine for a variety of diseases including infectious diseases. While the main clinical applications of immunoglobulin therapy concern their use as replacement for patients with primary immunodeficiencies, or as treatment for autoimmune and inflammatory disorders, their role in infectious disease is limited largely to viral and toxin neutralization and replacement therapy in patients with immunoglobulin deficiencies. Many aspects of the therapeutic regimen of immunoglobulins even in the established indications remain open. Recently, due to the worldwide surge of immunosuppression caused by AIDS, organ transplantation, cancer, and autoimmune therapies, as well as the emergence of multidrug-resistant bacteria, there has been renewed interest in the use of antibody preparation to prevent infections in high-risk groups.

Knowing the limitations of the current anti-infective armamentarium, approaches that target the host through manipulations to augment the host immune response provide a helpful aid to conventional treatment options. A substantial body of evidence has demonstrated that strategies aiming to support or stimulate immune response could be feasible approaches that would benefit immunocompromised patients. In the present chapter, we present contemporary indications of immunoglobulin administration for therapy and prophylaxis of infections in the immunocompromised population.

A new method for removing endotoxin from plasma using hemocompatible affinity chromatography technology, applicable for extracorporeal treatment of septic patients

The pathogenesis of sepsis begins with the proliferation of micro-organisms at a site of infection, followed by invasion of the bloodstream and other organs. Gram-negative bacteria account for a large part of sepsis cases. The structural component of Gram-negative bacteria, endotoxin or lipopolysaccharide (LPS), induces the synthesis and release of endogenous mediators of sepsis. A growing number of investigations of the molecular mechanisms occurring in sepsis, point to endotoxin as a central mediator leading to multi-organ failure and death. In numerous clinical trials, attempts to target molecules downstream of endotoxin have been made, but have not been associated with improved survival. We describe an affinity-based system for the selective removal of endotoxin from plasma. The small-scale device, a 1.5 ml cartridge, contains beads that bind endotoxin with high specificity and efficiency. In addition, evidence is presented that this device does not affect plasma hemostasis, nor does it activate the complement system. Taken together, these results represent a proof of principle for endotoxin removal from plasma, which may be of clinical value to treat sepsis by extracorporeal circulation of the blood through a scaled-up version of this endotoxin-removing device.

Targeting cytokines as a treatment for patients with sepsis: A lost cause or a strategy still worthy of pursuit?

Despite often knowing the aetiology of sepsis and its clinical course there has not been the anticipated advances in treatment strategies. Cytokines are influential mediators of immune/inflammatory reactions and in patients with sepsis high circulating levels are implicated in the onset and perpetuation of organ failure. Antagonising the activities of pro-inflammatory cytokines enhances survival in animal models of sepsis but, so far, such a therapeutic strategy has not improved patient outcome. This article addresses the questions of why encouraging laboratory findings have failed to be translated into successful treatments of critically ill patients and whether modifying cytokine activity still remains a promising avenue for therapeutic advance in severe sepsis. In pursuing this task we have selected reports that we believe provide an incisive, critical and balanced view of the topic.

Pathophysiology of sepsis-related cardiac dysfunction: driven by inflammation, energy mismanagement, or both?

Sepsis is a systemic inflammatory response that follows bacterial infection. Cardiac dysfunction is an important consequence of sepsis that affects mortality and has been attributed to either elevated inflammation or suppression of both fatty acid and glucose oxidation and eventual ATP depletion. Moreover, cardiac adrenergic signaling is compromised in septic patients and this aggravates further heart function. While anti-inflammatory therapies are important for the treatment of the disease, administration of anti-inflammatory drugs did not improve survival in septic patients. This review article summarizes findings on inflammatory and other mechanisms that are triggered in sepsis and affect cardiac function and mortality. Particularly, it focuses on the effects of the disease in metabolic pathways, as well as in adrenergic signaling and the potential interplay of the latter with inflammation. It is suggested that therapeutic approaches should include combination of anti-inflammatory treatments, stimulation of energy production, and restoration of adrenergic signaling in the heart.

Abandon the mouse research ship? Not just yet!

Many preclinical studies in critical care medicine and related disciplines rely on hypothesis-driven research in mice. The underlying premise posits that mice sufficiently emulate numerous pathophysiologic alterations produced by trauma/sepsis and can serve as an experimental platform for answering clinically relevant questions. Recently, the lay press severely criticized the translational relevance of mouse models in critical care medicine. A series of provocative editorials were elicited by a highly publicized research report in the Proceedings of the National Academy of Sciences (PNAS; February 2013), which identified an unrecognized gene expression profile mismatch between human and murine leukocytes following burn/trauma/endotoxemia. Based on their data, the authors concluded that mouse models of trauma/inflammation are unsuitable for studying corresponding human conditions. We believe this conclusion was not justified. In conjunction with resulting negative commentary in the popular press, it can seriously jeopardize future basic research in critical care medicine. We will address some limitations of that PNAS report to provide a framework for discussing its conclusions and attempt to present a balanced summary of strengths/weaknesses of use of mouse models. While many investigators agree that animal research is a central component for improved patient outcomes, it is important to acknowledge known limitations in clinical translation from mouse to man. The scientific community is responsible to discuss valid limitations without overinterpretation. Hopefully, a balanced view of the strengths/weaknesses of using animals for trauma/endotoxemia/critical care research will not result in hasty discount of the clear need for using animals to advance treatment of critically ill patients.

Anti-TNF-α therapy for patients with sepsis: a systematic meta-analysis

OBJECTIVE

In humans, the role of anti-tumour necrosis factor (TNF)-α therapy in severe sepsis and septic shock is debatable. The aim of this meta-analysis was to determine the efficacy of anti-TNF-α therapies against placebo in patients with severe sepsis or septic shock.

METHODS

A structured literature search was undertaken to identify randomised controlled trials (RCTs) conducted in patients with severe sepsis or septic shock receiving anti-TNF-α therapy or placebo. A meta-analysis on relative risk (OR) with a 95% confidence interval (95% CI) was performed.

RESULTS

Seventeen studies with a total of 8971 patients were included. When all forms of anti-TNF-α therapy were pooled together, there was a significant reduction of 28-day all-cause mortality with respect to placebo (OR = 0.91, 95% CI: 0.83-0.99; p = 0.04). Subgroup analysis showed that anti-TNF-α antibodies (monoclonal and polyclonal) reduced mortality (OR = 0.90, 95% CI: 0.81-0.99; p = 0.04). Monoclonal antibodies enhanced survival (OR = 0.91, 95% CI: 0.82-1.00; p = 0.05), while polyclonal antibodies or receptor blockers did not enhance survival (OR = 0.71, 95% CI: 0.39-1.28, p = 0.25; OR = 0.95, 95% CI: 0.78-1.17, p = 0.65). There was a trend towards better survival in patients with high levels of IL-6 (> 1000 pg/ml) and patients with shock if they were treated with anti-TNF-α therapy (OR = 0.85, 95% CI: 0.72-1.00; OR = 0.80, 95% CI: 0.62-1.04). Publication bias and statistical heterogeneity (I(2)  < 50% and p > 0.1) were absent. Sensitivity analysis suggests that these results are highly stable.

CONCLUSIONS

This meta-analysis suggests that in patients with severe sepsis (before shock), immunotherapy with anti-TNF-α monoclonal antibodies reduces overall mortality. In patients with shock or high levels of IL-6 (> 1000 pg/ml), anti-TNF-α therapy may improve survival.

Antitumor necrosis factor therapy is associated with improved survival in clinical sepsis trials: a meta-analysis

OBJECTIVES

Sepsis is a lethal syndrome annually affecting approximately 900,000 patients in the United States alone. Despite their benefit in rheumatoid disease, selective antitumor necrosis factor agents failed to improve outcome in early sepsis trials in the 1990s. However, data from additional sepsis trials testing these agents are now available. We therefore sought to determine the effect on survival of selective antitumor necrosis factor agents in randomized clinical sepsis trials..

DATA SOURCES

PubMed, Scopus, Embase, and Web of Science.

STUDY SELECTION

Randomized human sepsis trials of selective antitumor necrosis factor agents reporting survival rates.

DATA EXTRACTION

Two investigators independently collected relevant data on study characteristics, treatment interventions, and patients from each study.

DATA SYNTHESIS

Antitumor necrosis factor agents in 15 sepsis trials (n=8,896 patients) meeting inclusion criteria had similar effects (I=0, p=0.84) and compared with controls (placebo in 14 trials or a lower dose in one trial) overall decreased the relative risk of death (95% CI) (0.93 [0.88-0.98], p=0.01). In subgroup analysis, tumor necrosis factor monoclonal antibodies (10 trials, n=6,818) alone produced a significant survival benefit (0.93 [0.87, 0.99], p=0.02) (I=0, p=0.83). Tumor necrosis factor polyclonal antibodies (two trials, n=151) and low-molecular-weight soluble receptor (two trials, n=1,786) had similar beneficial effects to antitumor necrosis factor agents overall (0.82 [0.49-1.37], p=0.45; 0.93 [0.81-1.08], p=0.33, respectively). The effect of tumor necrosis factor high-molecular-weight soluble receptor (one trial, n=141) was not significantly different from other agents but was on the side of harm (1.50 [0.86-2.61], p=0.16).

CONCLUSION

Antitumor necrosis factor agents produced a modest but significant decrease in the risk of dying with sepsis. Prior individual trials failed to demonstrate benefit, likely because they were underpowered. A definitive trial demonstrating the potential benefit of such agents might require 10,000 or more patients with sepsis.

Intravenous immunoglobulin for treating sepsis, severe sepsis and septic shock

BACKGROUND

Mortality from sepsis and septic shock remains high. Results of trials on intravenous immunoglobulins (IVIG) as adjunctive therapy for sepsis have been conflicting. This is an update of a Cochrane review that was originally published in 1999 and updated in 2002 and 2010.

OBJECTIVES

To estimate the effects of IVIG as adjunctive therapy in patients with bacterial sepsis or septic shock on mortality, bacteriological failure rates, and duration of stay in hospital.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 6), MEDLINE (1966 to December 2012), and EMBASE (1988 to December 2012). We contacted investigators in the field for unpublished data. The original search was performed in 1999 and updated in 2002 and 2008.

SELECTION CRITERIA

We included randomized controlled trials comparing IVIG (monoclonal or polyclonal) with placebo or no intervention in patients of any age with bacterial sepsis or septic shock.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the studies for inclusion and undertook methodologic quality assessment and data abstraction. We conducted pre-specified subgroup analyses by type of immunoglobulin preparation.

MAIN RESULTS

We included 43 studies that met our inclusion criteria in this updated review out of 88 potentially eligible studies. The studies included a large polyclonal IVIG trial in neonates that was concluded in 2011 and classified as ongoing in the 2010 version of this review. Pooled analysis of polyclonal and monoclonal IVIG was not done due to clinical heterogeneity. Subgroup analysis of 10 polyclonal IVIG trials (n = 1430) and seven trials on IgM-enriched polyclonal IVIG (n = 528) showed significant reductions in mortality in adults with sepsis compared to placebo or no intervention (relative risk (RR) 0.81; 95% confidence interval (CI) 0.70 to 0.93 and RR 0.66; 95% CI 0.51 to 0.85, respectively). Subgroup analysis of polyclonal IVIG in neonates, which now includes the recently concluded large polyclonal IVIG trial, showed no significant reduction in mortality for standard IVIG (RR 1.00; 95% CI 0.92 to 1.08; five trials, n = 3667) and IgM-enriched polyclonal IVIG (RR 0.57; 95% CI 0.31 to 1.04; three trials, n = 164). Sensitivity analysis of trials with low risk of bias showed no reduction in mortality with polyclonal IVIG in adults (RR 0.97; 95% CI 0.81 to 1.15; five trials, n = 945) and neonates (RR 1.01; 95% CI 0.93 to 1.09; three trials, n = 3561). Mortality was not reduced among patients (eight trials, n = 4671) who received anti-endotoxin antibodies (RR 0.99; 95% CI 0.91 to1.06) while anti-cytokines (nine trials, n = 7893) demonstrated a marginal reduction in mortality (RR 0.92; 95% CI 0.86 to 0.97).

AUTHORS' CONCLUSIONS

Polyclonal IVIG reduced mortality among adults with sepsis but this benefit was not seen in trials with low risk of bias. Among neonates with sepsis, there is sufficient evidence that standard polyclonal IVIG, as adjunctive therapy, does not reduce mortality based on the inclusion of the large polyclonal IVIG trial on neonates. For Ig-M enriched IVIG, the trials on neonates and adults were small and the totality of the evidence is still insufficient to support a robust conclusion of benefit. Adjunctive therapy with monoclonal IVIGs remains experimental.

Animal models of sepsis

Sepsis remains a common, serious, and heterogeneous clinical entity that is difficult to define adequately. Despite its importance as a public health problem, efforts to develop and gain regulatory approval for a specific therapeutic agent for the adjuvant treatment of sepsis have been remarkably unsuccessful. One step in the critical pathway for the development of a new agent for adjuvant treatment of sepsis is evaluation in an appropriate animal model of the human condition. Unfortunately, the animal models that have been used for this purpose have often yielded misleading findings. It is likely that there are multiple reasons for the discrepancies between the results obtained in tests of pharmacological agents in animal models of sepsis and the outcomes of human clinical trials. One of important reason may be that the changes in gene expression, which are triggered by trauma or infection, are different in mice, a commonly used species for preclinical testing, and humans. Additionally, many species, including mice and baboons, are remarkably resistant to the toxic effects of bacterial lipopolysaccharide, whereas humans are exquisitely sensitive. New approaches toward the use of animals for sepsis research are being investigated. But, at present, results from preclinical studies of new therapeutic agents for sepsis must be viewed with a degree of skepticism.

Review of experimental animal models of biliary acute pancreatitis and recent advances in basic research

Acute pancreatitis (AP) is a formidable disease, which, in severe forms, causes significant mortality. Biliary AP, or gallstone obstruction-associated AP, accounts for 30-50% of all clinical cases of AP. In biliary AP, pancreatic acinar cell (PAC) death (the initiating event in the disease) is believed to occur as acinar cells make contact with bile salts when bile refluxes into the pancreatic duct. Recent advances have unveiled an important receptor responsible for the major function of bile acids on acinar cells, namely, the cell surface G-protein-coupled bile acid receptor-1 (Gpbar1), located in the apical pole of the PAC. High concentrations of bile acids induce cytosolic Ca(2+) overload and inhibit mitochondrial adenosine triphosphate (ATP) production, resulting in cell injury to both PACs and pancreatic ductal epithelial cells. Various bile salts are employed to induce experimental AP, most commonly sodium taurocholate. Recent characterization of taurolithocholic acid 3-sulphate on PACs has led researchers to focus on this bile salt because of its potency in causing acinar cell injury at relatively low, sub-detergent concentrations, which strongly implicates action via the receptor Gpbar1. Improved surgical techniques have enabled the infusion of bile salts into the pancreatic duct to induce experimental biliary AP in mice, which allows the use of these transgenic animals as powerful tools. This review summarizes recent findings using transgenic mice in experimental biliary AP.

Glibenclamide reduces proinflammatory cytokines in an ex vivo model of human endotoxinaemia under hypoxaemic conditions

AIMS

In vivo application of the K(ATP)-channel blocker glibenclamide can reverse endotoxin-induced hypotension, vascular hyporeactivity and shock in experimental animals. The hypothesis of the present study is, that the drug effects might not only be based on direct inhibition of K(ATP)-channels of vascular smooth muscle cells, but might also reflect reduction of shock-induced excess proinflammatory cytokines and procoagulatory molecules produced in the blood monocytes.

MAIN METHODS

Human whole blood (normoxaemic or hypoxaemic) supplemented ex vivo with 100 ng/ml LPS was used to assess glibenclamide (3-100 μM) effects on IL-1 beta, IL-6, TNF-alpha, tissue factor, and plasminogen-activator-inhibitor-2 (PAI-2). Co-incubations with monocytes and erythrocytes and cytosolic calcium measurements were performed to reveal their purinergic intercellular interaction.

KEY FINDINGS

In heparinized blood, glibenclamide reduced LPS-induced release of IL-1 beta and TNF-alpha, tissue factor and PAI-2 mRNA in a concentration-dependent manner. When samples were subjected to strong hypoxemia using 95% N(2)/5% CO(2), these parameters became even more sensitive to the drug. No drug effect was observable in citrated blood or in isolated monocytes. IL-1 beta mRNA inhibition by glibenclamide appeared to be dependent on P2X7-receptor activation of monocytes by ATP-releasing erythrocytes during hypoxia. Cytosolic calcium values as well as the duration of calcium transients elicited by P2X7-receptor stimulation in isolated monocytes were strongly increased during hypoxia, both of which could be abolished by glibenclamide.

SIGNIFICANCE

We conclude that the anti-inflammatory effect of glibenclamide is mainly based on the reduction of calcium entry by drug-induced depolarization of hypoxic monocytes. Thus, glibenclamide possesses a potentially beneficial shock-specific anti-inflammatory action.

Association of tumor necrosis factor β genetic polymorphism and sepsis susceptibility

The association of the tumor necrosis factor β (TNF-β) Nco1 genetic polymorphism with susceptibility to sepsis was evaluated in 60 consecutive patients diagnosed with sepsis and in 148 healthy blood donors. Genomic DNA was extracted from peripheral blood cells and a 782 base-pair fragment of the TNF-β gene was amplified by PCR. The PCR products were subjected to Nco1 restriction digestion and analysed by restriction fragment length polymorphism analysis. Tumor necrosis factor α (TNF-α) and the C-reactive protein (CRP) serum levels were also determined by ELISA and nephelometry, respectively. Among the septic patients, the allelic frequencies of TNFB1 and TNFB2 were 0.2833 and 0.7166, respectively, and they differed from those observed in the blood donors (p=0.0282). The TNFB2 allele frequency was higher in the septic patients than in the blood donors [odds ratio=1.65 (CI 95% 1.02-2.69), p=0.0315]. The TNF-α and CRP serum levels and the APACHE II and SOFA clinical scores did not differ in the patients with the TNFB1 or TNFB2 alleles (p>0.05). The results suggest that the TNFB2 allele is associated with susceptibility to sepsis, but it was not found to be associated with the immunological and clinical biomarkers of the disease.

Effects of TNF-alpha-converting enzyme inhibition on acute lung injury induced by endotoxin in the rat

We studied the effects of TNF-converting enzyme inhibition with Y-41654, which down-regulates the production of soluble TNF-alpha (sTNF-alpha), on acute lung injury induced by intratracheal administration of LPS. We first verified in vitro that pretreatment of isolated alveolar macrophages from Sprague-Dawley male rats with 20 microL of 0.1-mM Y-41654, decreased significantly (P < 0.05) the concentration of sTNF-alpha in cell supernatants induced by 10 microg/mL of LPS. We then studied four groups of rats (each n = 10) including 1) a control group, 2) an LPS group (300 microg /kg, instilled intratracheally), 3) a Y-41654 group, and 4) a treatment group treated with Y-41654 after LPS instillation. Y-41654, 10 mg/kg in 0.7 mL of phosphate-buffered saline, was administered (i.v.), 15 min before and 0.5, 1.5, 2.5, and 3.5 h after saline or LPS instillation. The animals were observed for 4 h. In the animals treated with Y-41654, the concentrations of sTNF-alpha and protein in bronchoalveolar lavage fluid, and the number of neutrophils in lung tissue and bronchoalveolar lavage fluid were significantly lower at 4 h than in the LPS group (P < 0.05). In conclusion, sTNF-alpha plays an important role in the development of acute lung injury induced by intratracheal administration of LPS, in part modulating neutrophil kinetics.

Severe sepsis and septic shock in the emergency department

Increased attention has focused recently on the acute management of severe sepsis and septic shock, conditions that represent the end-stage systemic deterioration of overwhelming infection. Clinical trials have identified new therapies and management approaches that, when applied early, appear to reduce mortality. Practice guidelines have been advanced by critical care societies, and many of the proposed interventions involve therapies other than antimicrobials directed at hemodynamic resuscitation or addressing adverse effects of the inflammatory cascade. Although many emergency departments (EDs) are now adopting treatment protocols for sepsis that are based on published treatment guidelines, recent research calls many of the initial recommendations into question, and validation trials of some of these approaches are ongoing. This article reviews the initial evaluation and treatment considerations of sepsis in the ED setting.

Role of tumor necrosis factor-alpha in acute pancreatitis: from biological basis to clinical evidence

Tumor necrosis factor (TNF)-alpha is a pleiotropic cytokine that exerts host-damaging effects in different autoimmune and inflammatory diseases. It is a key regulator of other proinflammatory cytokines and of leukocyte adhesion molecules, and it is a priming activator of immune cells. In recent years, several research lines-mostly derived from animal models and in vitro studies-suggested that TNF-alpha plays a pivotal role in the pathogenesis of acute pancreatitis. In particular, it contributes to the systemic progression of the inflammatory response and to the end-organ dysfunction often observed in severe disease. Current clinical applications of TNF-alpha in acute pancreatitis include the assessment of blood concentrations to predict disease severity and to identify individuals prone to develop complications such as multiple organ failure and septic shock. However, TNF-alpha is rapidly cleared from the bloodstream, and sensitivity and overall accuracy of its measurement seem strictly time dependent, thereby being of potential prognostic value only in the first days after the onset of the disease. In parallel, TNF-alpha has been evaluated as a novel pharmacologic target for treating pancreatitis. Although promising results have been observed in the laboratory, transition to clinical practice seems problematic, in particular, in the light of divergent results obtained in sepsis trials. Therefore, in future clinical trials pertaining to TNF-alpha neutralization in acute pancreatitis, timing of intervention should be related to changes in TNF-alpha serum levels, and inclusion and exclusion criteria should be accurately selected to better define the population most likely to benefit.

Pathophysiology of sepsis

Sepsis remains a critical problem with significant morbidity and mortality even in the modern era of critical care management. Multiple derangements exist in sepsis involving several different organs and systems, although controversies exist over their individual contribution to the disease process. Septic patients have substantial, life-threatening alterations in their coagulation system, and currently, there is an approved therapy with a component of the coagulation system (activated protein C) to treat patients with severe sepsis. Previously, it was believed that sepsis merely represented an exaggerated, hyperinflammatory response with patients dying from inflammation-induced organ injury. More recent data indicate that substantial heterogeneity exists in septic patients' inflammatory response, with some appearing immuno-stimulated, whereas others appear suppressed. Cellular changes continue the theme of heterogeneity. Some cells work too well such as neutrophils that remain activated for an extended time. Other cellular changes become accelerated in a detrimental fashion including lymphocyte apoptosis. Metabolic changes are clearly present, requiring close and individualized monitoring. At this point in time, the literature richly illustrates that no single mediator/system/pathway/pathogen drives the pathophysiology of sepsis. This review will briefly discuss many of the important alterations that account for the pathophysiology of sepsis.

The occurrence of severe sepsis and septic shock are related to distinct patterns of cytokine gene expression

Patient response to acute bacterial infection is highly variable. Differing outcomes in this setting may be related to variations in the immune response to an infectious insult. Using quantitative real-time polymerase chain reaction, we quantified gene expression of the tumor necrosis factor alpha(TNFalpha), interferon gamma (IFNgamma), and interleukin 10 (IL10), IL12p35, and IL4 genes in 3 patient groups. These groups consisted of an intensive care unit (ICU) cohort who presented with severe sepsis or septic shock, a group of noncritically ill ward patients with documented Gram-negative bacteremia, and a group of healthy controls. Greater interleukin 10 messenger RNA (mRNA) levels were detected in the ICU group in comparison with both the bacteremic and control groups (P < 0.0001). More TNF-alpha mRNA was detected in the ICU group when compared with the control group (P < 0.0001). However, TNF-alpha mRNA was most abundant in the bacteremic group (P = 0.0007). Lesser IFN-gamma mRNA levels were detected in the ICU group when compared with both the bacteremic and control groups (P < 0.0003). Cytokine mRNA levels were not associated with the occurrence of shock upon admission to ICU. On the seventh day of ICU stay, the presence of shock was associated with lesser IFN-gamma mRNA (P = 0.0004) and lesser TNF-alpha mRNA (P = 0.001). Survivors had greater TNF-alpha mRNA copy numbers on day 7 of ICU stay than nonsurvivors (P = 0.002). We conclude that a proinflammatory response is the appropriate response in the setting of infection and is associated with lesser requirements for inotropes and lesser mortality. Quantitative real-time polymerase chain reaction can be used to predict infection outcome in clinically relevant situations where enzyme-linked immunosorbent assay testing has proved disappointing.

Severe sepsis and septic shock: review of the literature and emergency department management guidelines

Severe sepsis and septic shock are as common and lethal as other acute life-threatening conditions that emergency physicians routinely confront such as acute myocardial infarction, stroke, and trauma. Recent studies have led to a better understanding of the pathogenic mechanisms and the development of new or newly applied therapies. These therapies place early and aggressive management of severe sepsis and septic shock as integral to improving outcome. This independent review of the literature examines the recent pathogenic, diagnostic, and therapeutic advances in severe sepsis and septic shock for adults, with particular relevance to emergency practice. Recommendations are provided for therapies that have been shown to improve outcomes, including early goal-directed therapy, early and appropriate antimicrobials, source control, recombinant human activated protein C, corticosteroids, and low tidal volume mechanical ventilation.

Cytokines and Escherichia coli Sepsis

This review reviews the critical role played by cytokines in the pathogenesis of Escherichia coli sepsis. It focuses on prototypic pro-inflammatory and anti-inflammatory cytokines and their influence on mortality in experimental animal models of E. coli endotoxemia and of live E. coli sepsis. The review reviews the results of clinical trials on anticytokine therapy in patients with severe sepsis or septic shock. The recognition of the critical role played by tumor necrosis factor (TNF), a secreted 17kDa cytokine, in endotoxic and gram-negative shock has been a major step forward in our understanding of the pathogenesis of sepsis. The review describes the role of TNF, IL1, and IL6 in animal models of E. coli endotoxemia and sepsis. Given the pivotal role played by TNF in experimental sepsis and the fact that elevated concentrations of TNF were detected in the circulation of patients with sepsis, anti-TNF treatment strategies were investigated as adjunctive therapy for severe sepsis and septic shock. Several studies demonstrated that high levels of interleukin-6 (IL-6) are associated with an increased risk for fatal outcome. Gamma interferon (IFN-γ), IL-12, and IL-18 are functionally related cytokines. A recent study has indicated that transgenic mice overexpressing IL-15 are resistant to an otherwise lethal intraperitoneal E. coli challenge. IL4, IL10, and IL13are prototypic anti-inflammatory cytokines. Their classification as anti-inflammatory cytokines is based on the observation that these molecules inhibit the production of proinflammatory cytokines (primarily TNF and IL1) and toxic oxygen and reactive nitrogen species by myeloid cells.

Effect of drotrecogin alfa (activated) on human endothelial cell permeability and Rho kinase signaling

OBJECTIVE

To explore whether the improvement in organ function and the vasoactive effect observed in the clinical studies of drotrecogin alfa (activated) (recombinant human activated protein C, rhAPC) in sepsis are a result of rhAPC's effect on endothelial cell (EC) permeability and modulation of the intracellular cytoskeleton via the Rho kinase signaling pathway.

DESIGN

Findings regarding dose and duration of exposure to the drug with sequential addition of rhAPC and mediators (thrombin, histamine, interleukin-1 beta).

SETTING

Research laboratory in a pharmaceutical company.

SUBJECTS

Cultured primary human EC from different tissues and vascular beds.

INTERVENTIONS

A monolayer of EC was incubated with either rhAPC, thrombin, histamine, or interleukin-1 beta alone or with rhAPC in combination with thrombin or interleukin-beta. The effect of rhAPC and mediators on EC permeability was monitored with measurement of electrical resistance. The effect on Rho kinase pathway signaling was monitored by the levels of phosphorylated myosin light chain and blockage with the Rho kinase specific inhibitor, Y27632.

MEASUREMENTS AND MAIN RESULTS

Thrombin alone induced an early, concentration-dependent, and transient leakiness of EC. Interleukin-1 beta (0.5 ng/mL) induced an early, irreversible leakiness of EC. rhAPC (0.05-0.2 microg/mL, approximate median therapeutic blood levels) alone had no effect on EC permeability. rhAPC at > or=1 microg/mL induced an early EC leakage. rhAPC (0.19 microg/mL) attenuated the leakage induced by 0.5 ng/mL interleukin-1beta on microvascular EC derived from lung and skin and partially attenuated the leakage induced by 0.25 nM thrombin on human coronary arterial ECs. Levels of phosphorylated myosin light chain increased rapidly in human coronary arterial ECs when stimulated with thrombin or rhAPC (about 100-fold less potent) in a concentration-dependent manner via the Rho kinase signaling pathway. Short (5 mins) preconditioning of human coronary arterial ECs with 0.19 microg/mL rhAPC partially blocked the increase in phosphorylated myosin light chain levels induced by thrombin (0.06-0.2 nM).

CONCLUSIONS

At concentrations exceeding physiologic and therapeutic levels, rhAPC increases EC permeability, an effect not seen at lower concentrations. The data suggest that interpretation of published in vitro and in vivo data of rhAPC and EC permeability should take into consideration the concentrations of rhAPC used or achieved. Other preliminary novel observations suggest that studying the effects of rhAPC on EC permeability and intracellular cytoskeletal organization may provide understanding of the effect of rhAPC on EC function.

CDP 571: anti-TNF monoclonal antibody, BAY 103356, BAY W 3356, Humicade

CDP 571 [anti-TNF monoclonal antibody, BAY 103356, BAY W 3356, Humicade] is a recombinant humanised antibody directed against tumour necrosis factor (TNF). CDP 571 has an advantage over the mouse/human chimera anti-TNF-alpha antibody, nerelimomab, in that it is suitable for multiple dosing as it is not so immunogenic. Celltech constructed CDP 571 by grafting the section of mouse antibody that recognises TNF onto a human IgG4 antibody. In the third quarter of 1999, Celltech merged with Chiroscience to form Celltech Chiroscience. In January 2000, Medeva was merged into Celltech Chiroscience, which was renamed as Celltech Group. The research division of Celltech Group is now called Celltech R&D (formerly Celltech Chiroscience Discovery) and the manufacturing and marketing division is called Celltech Pharmaceuticals (formerly Celltech Medeva Pharma). Celltech has completed two phase III trials, involving around 670 patients with moderate-to-severe Crohn's disease; however, both these trials failed to meet their primary endpoints. Biogen and Celltech group will review the scope of their collaboration following additional analysis of the phase III data and discussions with regulatory authorities. The Celltech Group intends to devote significant resources towards enhancing the capability of Celltech Pharmaceuticals to market CDP 571 and other new drugs (such as CDP 860 and CDP 870) as specialised hospital products. Phase II trials were underway in the United Kingdom for use of the drug in the treatment of type 2 diabetes mellitus. However, these trials have also been discontinued. Celltech Group is no longer developing CDP 571 for septic shock, based on negative results with the related compound nerelimomab. The compound was in phase III trials for septic shock in France, Belgium, the United Kingdom, Germany and the US. Celltech also plans to investigate the use of CDP 571 in psoriasis via a collaboration with Biogen (USA). In January 2002, AFX (Agence France-Presse and the Financial Times Group) reported that analysts at Morgan Stanley have forecast Humicade trade mark to reach sales of 250 million US dollars in 2008--at that time, the market value for anti-TNF products to treat rheumatoid arthritis and Crohn's disease will exceed 4 billion US dollars, according to Morgan Stanley.

Advances in sepsis therapy

During the past 3 years new insights have been gained into the fundamental elements that underlie the pathogenesis of sepsis, and after years of frustrating failures, progress in the basic understanding of sepsis has translated into successful new therapies. These new treatment strategies have significantly improved the outcome of patients experiencing the puzzling syndrome of severe sepsis. More effective supportive therapies with early, goal-oriented therapy including volume resuscitation, catecholamine therapy and transfusion improve the chances for survival in septic shock. Novel endocrine management with hydrocortisone replacement therapy for relative adrenal insufficiency in septic shock patients and strict blood glucose control provide a survival advantage in critically ill patients. Administering appropriate antimicrobial therapy, nutritional support and ventilation protocols with low tidal volumes have now been shown to benefit septic patients. Finally, human recombinant activated protein C (drotrecogin alfa), which ameliorates sepsis-induced disseminated intravascular coagulation and exerts several other favourable effects on endothelial cells, has been shown to reduce mortality in patients with severe sepsis. On the basis of newly discovered pathophysiological mechanisms of sepsis, several other adjuvant therapies for sepsis are in various stages of preclinical and clinical development. Individualised and optimal supportive care with efforts to reverse the precipitating cause of sepsis remains the mainstay of therapy for severe sepsis. How these new and often expensive regimens will fit into the standard treatment approach to sepsis remains to be defined by future clinical investigations.

Protection from endotoxemia by adenoviral-mediated gene transfer of human bactericidal/permeability-increasing protein

Sepsis represents a growing concern in high-risk patients and there has been a lack of effective preventives and therapies. Bacterial/permeability increasing protein (BPI) is a human neutrophil granule-associated defense molecule specific for Gram-negative bacteria and their products. To develop a BPI-transgene-based prophylactic or therapeutic modality, we have developed a recombinant, replication-deficient adenoviral vector expressing full-length human BPI protein (AdhBPI). The expression of BPI is under control of a murine cytomegalovirus (CMV) promoter. Using in vitro and in vivo systems, AdhBPI-mediated gene transfer led to extracellular secretion of BPI protein, which effectively neutralized endotoxin (lipopolysaccharide [LPS]) and markedly reduced the production of proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and macrophage inflammatory protein 2 (MIP-2) by freshly isolated murine alveolar macrophages. By using a mouse model of nonlethal sepsis elicited with LPS, we demonstrated that in vivo gene transfer of BPI was able to markedly inhibit the effect of a large dose of LPS on cytokine responses when injected intraperitoneally. Furthermore, such in vivo BPI gene transfer also improved the survival of mice suffering from lethal septic shock elicited by intraperitoneal injection of d-galactosamine and LPS. Thus, our results suggest that human BPI gene transfer vector has the potential to be used as a therapeutic agent for septic conditions.

Such stuff as dreams are made on: mediator-directed therapy in sepsis

Sepsis, a life-threatening disorder that arises through the body's response to infection, is the leading cause of death and disability for patients in an intensive care unit. Advances in the understanding of the complex biological processes responsible for the clinical syndrome have led to the identification of many promising new therapeutic targets, including bacterial toxins, host-derived mediators, and downstream processes such as coagulation and the endocrine response. Diverse therapies directed against these targets have shown dramatic effects in animal models; however, in humans, their impact has been frustratingly modest, and only one agent--recombinant activated protein C--has achieved regulatory approval. This review summarizes the approaches that have been evaluated in clinical trials, explores the reasons for the discordance between biological promise and clinical reality, and points to approaches that may lead to greater success in the future.

The problems and challenges of immunotherapy in sepsis

Despite decades of research, the morbidity and mortality of sepsis and septic shock remain very high. To further compound the problem, results from all investigative trials (with one exception) have shown that tested immunotherapies aimed at modulating the excessive expression of key cytokines, such as the interleukins and tumor necrosis factor, have been either equivalent or inferior to placebo. While controversy prevails in terms of continuing such investigative trials, study designs can be held accountable for inherent flaws. Testing for the wrong hypothesis, errant study design, using the wrong agent, focusing on an inappropriate target group, excessive expectations, and uncontrolled variables have potentially obscured the real efficacy such agents might have to offer. By standardizing protocols and reducing uncontrolled variables, research can be more precisely targeted so as to unmask the real benefits to the patient.

Increasing the efficacy of anti-inflammatory agents used in the treatment of sepsis

Excessive production of inflammatory mediators during invasive infection plays a key role in the pathogenesis of septic shock. In an attempt to improve survival of patients with this lethal syndrome, agents were developed to selectively inhibit mediators in this inflammatory response. Despite promising preclinical results, several different mediator-specific anti-inflammatory agents failed to demonstrate significant benefit in patients. There was, however, a significant difference in mortality between preclinical and clinical trials. The median control mortality in preclinical trials, performed almost uniformly in highly lethal sepsis models, was 88%. In clinical trials however, the median control mortality rate was much lower, at 41%. A recent meta-regression analysis of these preclinical and clinical trials in combination with prospective confirmatory studies demonstrated that risk of death as assessed by control group mortality rate significantly altered the treatment effect of these agents in both humans and animals. While anti-inflammatory agents were very beneficial in groups with high control mortality rates, they were ineffective or harmful in groups with low control mortality rates. Thus, variation in the risk of death due to sepsis provides a basis for the marked difference in the efficacy of these anti-inflammatory agents in preclinical and clinical trials over the last decade. In contrast to mediator-specific anti-inflammatory agents, glucocorticoids and activated protein C have recently demonstrated significant beneficial effects in individual clinical trials. However, glucocorticoids were studied only in patients with vasopressor-dependent septic shock, which is associated with a high control mortality rate (i.e. 61%) similar to the level at which mediator-specific agents would have been expected to be markedly beneficial. Furthermore, consistent with earlier findings for mediator-specific anti-inflammatory agents, analysis of the activated protein C study also demonstrated a relationship between risk of death and effect of treatment. Developing better methods to define high-risk septic populations for treatment with anti-inflammatory agents will increase the efficacy of this therapeutic approach and minimize its potential for harm.

Risk and the efficacy of antiinflammatory agents: retrospective and confirmatory studies of sepsis

We investigated whether a relationship between risk of death and treatment effect could explain the disparate results between the preclinical and clinical sepsis trials of antiinflammatory agents over the last decade. A metaregression analysis of cited preclinical studies showed that the treatment effects of these agents were highly dependent on risk of death (p = 0.0001) and that animals were studied at significantly higher control mortality rates than humans (median [25th-75th quartile], 88% [79-96%] versus 39% [32-42%], p = 0.0001). An analysis of the clinical trials showed that antiinflammatory agents were also significantly more efficacious in septic patients with higher risk of death (p = 0.002) and were harmful in those with low risk. To test this relationship prospectively, we studied antiinflammatory agents in models employing differing doses of bacterial challenge to produce the full range of risk of death. We found that the efficacy of these agents, although very beneficial at high control mortality rates, was much reduced (p = 0.0001) and similar to those in human trials at moderate control mortality rates (i.e., 30 to 40%). The efficacy of antiinflammatory agents during sepsis is dependent on the risk of death, an observation that explains the apparent contradiction between preclinical and clinical trial results. Accounting for this relationship may be necessary for the safe and effective development of antiinflammatory therapies for sepsis.

Cytokine modulation in sepsis and septic shock

Sepsis and septic shock are a major cause of morbidity and mortality in patients admitted to the intensive care unit. Since the introduction of antibiotic therapy, the mortality associated with sepsis has remained within the 30- 50% range. Sepsis constitutes the systemic response to infection. This response encompasses both pro-inflammatory and anti-inflammatory phases that are marked by the sequential generation of pro- and anti-inflammatory cytokines. Among the most important pro-inflammatory cytokines are TNF-alpha and IL-1beta. The pro-inflammatory effects of such cytokines are inhibited by soluble receptors/receptor antagonists and anti-inflammatory cytokines including IL-10 and transforming growth factor-beta. Modulation of the activity of both pro- and anti-inflammatory cytokines to improve outcome in patients with sepsis has been subject of multiple clinical studies. This review will examine clinical trials evaluating several strategies for blocking or attenuating TNF-alpha and IL-1beta activity. This review will also survey the current state of experimental therapies involving IL-10, transforming growth factor-beta, granulocyte colony-stimulating factor and IFN-phi. Finally, newer developments related to less known cytokines such as macrophage migration inhibitory factor and high mobility group 1 protein will be evaluated.

Pharmacology of acute lung injury

The acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a clinical syndrome that affects both medical and surgical patients. To date, despite improved understanding of the pathogenesis of ALI/ARDS, pharmacological modalities have been unsuccessful in decreasing mortality. However, several pharmacological agents for ARDS are in development and have shown great promise. In addition to the anti-inflammatory category including late corticosteroids, inhaled nitric oxide, alveolar surfactant, and vasodilators are being evaluated. Replacements of anticoagulation mediators have also suggested beneficial effects on the patient outcome. This article provides an overview of pharmacological treatments of ALI/ARDS.

Future of monoclonal antibodies in the treatment of hematologic malignancies

BACKGROUND

The approval of monoclonal antibodies (MAbs) as antibody-targeted therapy in the management of patients with hematologic malignancies has led to new treatment options for this group of patients. The ability to target antibodies to novel functional receptors can increase their therapeutic efficacy.

METHODS

The authors reviewed improvements in MAb design to enhance their effectiveness over the existing therapeutic MAb currently approved for treating hematologic malignancies.

RESULTS

Three classes of therapeutic MAbs showing promise in human clinical trials for treatment of hematologic malignancies include unconjugated MAb, drug conjugates in which the antibody preferentially delivers a potent cytotoxic drug to the tumor, and radioactive immunotherapy in which the antibody delivers a sterilizing dose of radiation to the tumor.

CONCLUSIONS

A better appreciation of how MAbs are metabolized in the body and localized to tumors is resulting in the development of new antibody constructs with improved biodistribution profiles.

Randomized, controlled clinical trials in sepsis: has methodological quality improved over time?

OBJECTIVE

To systematically evaluate the methodological quality of randomized clinical trials and to determine whether randomized clinical trials of sepsis improved in methodological quality over time.

DATA SOURCES

Computerized MEDLINE search of articles published in any language from 1966 to 1998 combined with a manual search of bibliographies of published articles and communication with known experts in the field.

STUDY SELECTION

All randomized clinical trials of sepsis, severe sepsis, and septic shock performed in adults and published as full articles.

DATA EXTRACTION

Abstracts of all retrieved records were reviewed and the inclusion criteria were applied. All selected articles were classified into (a) trials designed to detect differences in mortality as the primary end point, or (b) trials focusing on surrogate outcome measures (i.e., physiological or biochemical parameters). All retrieved trials were then graded for methodological quality using an objective grading scheme developed specifically for this study. The data selection and extraction process was carried out independently by two of the authors; any disagreement was resolved by discussion.

DATA SYNTHESIS

Seventy-four randomized clinical trials involving septic patients qualified for inclusion in this study (40 reporting mortality outcomes, 34 reporting other surrogate outcomes). Trials reporting mortality as the primary outcome had significantly higher quality scores compared with trials reporting surrogate outcome measures (29.6 +/- 1.0 vs. 24.3 +/- 0.8, p =.0006). From 1976 to 1998, trial methodology improved significantly over time (an average of 0.36 points per year, p =.021). Mortality outcome trials improved an average of 0.58 points per year (p =.0011) whereas surrogate outcome trials did not demonstrate an improvement in methodological quality over time (p =.249).

CONCLUSION

The methodological limitations identified in this article can help to target further improvement in trial design to enhance the validity of findings from future randomized clinical trials of sepsis.

Intravenous immunoglobulin for treating sepsis and septic shock

BACKGROUND

Death from severe sepsis and septic shock is common, and researchers have explored whether antibodies to the endotoxins in some bacteria reduces mortality.

OBJECTIVES

To estimate the effects of intravenous immunoglobulin (IVIG) in patients with bacterial sepsis or septic shock on mortality, bacteriological failure rates, and duration of stay in hospital.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group specialized register up to November 2001; the Cochrane Controlled Trials Register, The Cochrane Library issue 4, 2001; MEDLINE 1966 to November 2001; and EMBASE 1988 to September 2001. We contacted investigators active in the field for unpublished data.

SELECTION CRITERIA

Randomised trials comparing intravenous immunoglobulin (monoclonal or polyclonal) with placebo or no intervention, in patients with bacterial sepsis or septic shock.

DATA COLLECTION AND ANALYSIS

Inclusion criteria, trial quality assessment, and data abstraction were done in duplicate. We conducted pre-specified subgroup analyses by type of immunoglobulin preparation.

MAIN RESULTS

Twenty-seven out of 55 studies met our inclusion criteria. Pooled analysis of all types of IVIG preparations revealed a significant trend toward reduction of mortality (n= 8,856; RR=0.91; 95%CI 0.86-0.96). Overall mortality was reduced in patients who received polyclonal IVIG (n=492; RR=0.64; 95% CI 0.51 to 0.80). For the two high-quality trials on polyclonal IVIG, the RR for overall mortality was 0.30, but the confidence interval was wide (95% CI 0.09 to 0.99, n=91). Mortality was not reduced among patients who received monoclonal antibodies such as anti-endotoxins (n=2,826 in 5 good-quality studies; RR=0.97; 95% CI 0.88 to 1.07) or anti-cytokines (n=4,318; RR=0.93; 95% CI 0.86 to 1.01). A few studies measured secondary outcomes (deaths from sepsis or length of hospitalisation) but no differences in the intervention and control groups were identified except among those who received polyclonal IVIG, where sepsis-related mortality was significantly reduced (n=161; RR=0.35; 95% CI 0.18 to 0.69).

REVIEWER'S CONCLUSIONS

Polyclonal IVIG significantly reduced mortality and and is a promising adjuvant in the treatment of sepsis and septic shock. However, all the trials were small and the totality of the evidence is insufficient to support a robust conclusion of benefit. Adjunctive therapy with monoclonal IVIGs remains experimental.

Safety and dose relationship of recombinant human activated protein C for coagulopathy in severe sepsis

OBJECTIVES

To assess the safety and effect on coagulopathy of a range of doses of recombinant human activated protein C (rhAPC). To determine an effective dose and duration of rhAPC for use in future clinical trials.

DESIGN

Double-blind, randomized, placebo-controlled, multicenter, dose-ranging (sequential), phase II clinical trial.

SETTING

Forty community or academic medical institutions in United States and Canada.

PATIENTS

One hundred thirty-one adult patients with severe sepsis.

INTERVENTIONS

Intravenous infusion of rhAPC (12, 18, 24, or 30 microg/kg/hr) or placebo for 48 or 96 hrs.

MEASUREMENTS AND MAIN RESULTS

No significant differences in incidence of serious bleeding events (4% rhAPC, 5% placebo, p >.999) or incidence of serious adverse events (39% rhAPC, 46% placebo, p = 0.422) between rhAPC- and placebo-treated patients were observed. One of 53 rhAPC-treated patients with suitable immunogenicity samples had a low level, transient, non-neutralizing anti-APC antibody response not associated with any clinical adverse event. Significant dose-dependent decreases in both D-dimer (p <0.001) and end of infusion interleukin 6 levels (p =.021) were demonstrated. No statistically significant effects on fibrinogen or platelet counts were observed. A nonstatistically significant 15% relative risk reduction in 28-day all-cause mortality was observed between rhAPC- and placebo-treated patients.

CONCLUSIONS

rhAPC was safe and well-tolerated and demonstrated a dose-dependent reduction in D-dimer and interleukin 6 levels relative to placebo. The dose of 24 microg/kg/hr for 96 hrs was selected for use in future clinical studies.

A review of modifications to recombinant antibodies: attempt to increase efficacy in oncology applications

Although monoclonal antibodies have high specificity, their usefulness in the clinic, especially against solid tumors, has been limited. This arises in part from the inability of antibody molecules to penetrate into the tumor and kill the tumor cells. In addition, natural cytotoxic effects of antibodies, mediated through complement or Fc receptors, may not be sufficient to kill malignant cells. This review will present some of the antibody modifications used to increase efficacy. Modified recombinant antibodies have been designed to be more cytotoxic (immunotoxins), to increase natural effector functions (bivalent antibodies, antibody-fusion molecules, multimeric antibodies, directed mutations in Fc region), or to pretarget cells for concentration of cytotoxic drugs. This review will also focus on engineering of smaller versions of antibodies that retain specificity (single chain Fvs, Fabs, Fab(2)s, minibodies, domain deleted antibodies) and have increased penetrability of solid tumors. Many of these antibody modifications may result in antigenic compounds which can limit repeat administration. Clinical experiences will be highlighted if information is available.

Anti-tumor necrosis factor therapy in sepsis: update on clinical trials and lessons learned

OBJECTIVE

Tumor necrosis factor (TNF) is an important mediator involved in the pathogenesis of sepsis. We review clinical studies investigating the efficacy of anti-TNF therapy in decreasing mortality rates in septic patients.

DATA SOURCES

We conducted a computerized bibliographic search of randomized, clinical, multicenter trials studying the effects of anti-TNF therapy in the treatment of sepsis. We included all primary studies, reviewed all published meta-analyses, and contacted primary investigators of multicenter trials where necessary.

DATA SYNTHESIS

Almost all randomized studies targeting TNF during sepsis show a small, albeit nonsignificant, benefit in decreasing mortality. Strategies using monoclonal antibodies are more effective than are strategies using TNF receptor proteins. Analysis of randomized multicenter trials shows a small but significant benefit with anti-TNF therapeutic strategies. Furthermore, a recent study in 2634 septic patients using a murine anti-TNF antibody shows a 3.6% significant benefit in reducing mortality.

CONCLUSIONS

Anti-TNF strategies are only partially effective in patients with sepsis. Although individual studies show small, nonsignificant benefits, analysis of all trial data as well as data from a recent trial in a large population of septic patients show that anti-TNF strategies may confer a small survival benefit. Better characterization of patients and a more multimodal approach by concomitantly targeting other mediators involved in sepsis may be helpful in enlarging the clinical benefit of anti-TNF therapy.

Humanized anti-ganglioside GM2 antibody is effective to induce antibody-dependent cell-mediated cytotoxicity in mononuclear cells from lung cancer patients

Ganglioside GM2 is one of the major gangliosides expressed on the cell surface of human tumors including lung cancer. We have previously reported that a mouse-human chimeric monoclonal antibody (mAb), KM966, against GM2 promotes the lysis of lung cancer cells by human blood mononuclear cells (MNC) of healthy donors. In this study, we examined antibody-dependent cell-mediated cytotoxicity (ADCC) of MNC, using KM966 mAb and its humanized counterpart, KM8969, in 16 lung cancer patients and 18 control patients. The ADCC activity was assessed by 4-h (51)Cr release from GM2 positive SBC-3 small cell lung cancer cells. MNC from lung cancer patients exhibited similar ADCC activity to those from control patients when KM966 and KM8969 were used as mAb. Moreover, effective ADCC activity was observed even in MNC from advanced lung cancer patients. These observations suggest the potential activity of humanized anti-GM2 mAb (KM8969), as well as chimeric KM966, in biological therapy for lung cancer patients.

[Value of anti-TNF-alpha molecules in inflammatory and infectious diseases]

INTRODUCTION

The pathophysiological interest of tumor necrosis factor-alpha (TNF-alpha) has been recently reported in inflammatory and infectious diseases. Thus, TNF-alpha blockade has become a new field of therapeutical research.

CURRENT KNOWLEDGE AND KEY POINTS

Several biological agents specifically directed against TNF-alpha are available: anti-TNF-alpha monoclonal antibodies on the one hand--either mainly murine sequence (cA2), partially humanized (CDP 571) or fully human (D2E7)--and TNF-alpha soluble receptors on the other hand (lenercept or etanercept). The first clinical studies reveal interesting results. In rheumatoid arthritis (cA2, etanercept), these molecules may be used either alone or in synergistic combination with methotrexate. They produce a significant response compared to placebo or methotrexate alone, without loss of efficacy in medium-term treatment. In Crohn's disease (cA2 CDP571), they reduce significantly the activity of the disease, compared to placebo, and cA2 makes it possible to accelerate closure of the fistulas. The studies of severe sepsis did not reveal a significant efficacy, however, and only one study has been published on malignant disease, with a possible interesting effect. Even if these medications are usually well tolerated, the frequency of infections is slightly increased. The development of anti-DNA antibodies has also been reported, but drug-induced lupus is highly unusual.

FUTURE PROSPECTS AND PROJECTS

Further studies will define the place of anti-TNF-alpha biological agents among the other available treatments of rheumatoid arthritis and Crohn's disease. Because of their high cost, these drugs will probably be limited to patients with active inflammatory disease despite more conventional treatments.

Interleukin-1 receptor antagonist as an adjunct in the treatment of Haemophilus influenzae otitis media in the chinchilla

OBJECTIVES

This purpose of this study was to investigate the effect of blockade of the inflammatory cytokine pathway on experimentally induced otitis media in the chinchilla model.

STUDY DESIGN

Pilot, randomized placebo-controlled trial.

METHODS

Ampicillin-sensitive Haemophilus influenzae otitis media was induced in 45 adult chinchillas. The animals were randomly assigned to the following treatment groups: 1) transbullar injections (TBI) of interleukin-1 receptor antagonist (IL-1ra) and intramuscular ampicillin, 2) TBI of saline and intramuscular ampicillin, 3) TBI of IL-1ra and intramuscular sa-1 line or 4) TBI of saline and intramuscular saline. Blinded investigators measured resolution of otitis media by otomicroscopy, tympanogram, and culture results.

RESULTS

Comparisons were made between the treatment groups to assess the ability of IL-1ra to assist with resolution of otitis media using exact two-group binomial tests with the StatXact statistical program. The group with TBI of IL-1ra and intramuscular ampicillin as a treatment demonstrated trends suggesting more rapid resolution of positive cultures and more rapid and complete return to normal results on tympanograms and otomicroscopic findings compared with the group treated with TBI of saline and intramuscular ampicillin. These trends did not achieve statistical significance with the relatively small sample sizes used in this pilot study.

CONCLUSIONS

This investigation provides further evidence that the inflammatory cytokine cascade plays a significant role in the pathophysiology of otitis media and that modulation of this inflammatory pathway may provide novel and efficacious treatments for otitis media Further studies with larger groups of animals are warranted to determine whether the trends identified in this pilot study are reproducible and achieve statistical significance.

Anti-inflammatory therapies in sepsis and septic shock

Despite advances in supportive care, the morbidity and mortality rate resulting from sepsis and septic shock remain high (30 - 50%). A central hypothesis driving sepsis research in recent years is that this syndrome is the result of excessive inflammation. Therapies designed to inhibit the inflammatory response were first shown to be markedly beneficial in animal models of sepsis and then tested in numerous clinical trials involving thousands of patients. Three broad anti-inflammatory strategies have been investigated. First, glucocorticoids in high doses administered at the onset of sepsis were studied. This approach proved unsuccessful. More recently, however, glucocorticoids in lower doses have been found to have a beneficial effect in patients with septic shock. Whether the mechanism of this treatment benefit is through inhibition of inflammation, or by counteracting a relative steroid refractoriness occurring during sepsis, remains unknown. The next focus of research were agents active against the endotoxin molecule. However, as with the experience with glucocorticoids, this approach lacked a consistent pattern of efficacy. It is unclear if this lack of efficacy is the result of endotoxin being a poor therapeutic target, or from testing agents which lacked the appropriate biological activity. Most recently, clinical trials in sepsis have focused on inhibiting specific host pro-inflammatory mediators (e.g., TNF, interleukins). While individual trials of inhibitors of these pro-inflammatory mediators failed to show a convincing benefit, pooling the results of these trials suggest that this approach has a marginal effect, supporting a role for excessive inflammation in sepsis. An unanswered question is reconcilling the very favourable effects obtained with anti-inflammatory treatments in animal models with the marginal results in humans. Further clinical and laboratory research is needed and may provide insight into more effective ways to use the anti-inflammatory agents already tested, or to investigate other potentially more effective anti-inflammatory agents in this syndrome.