Activated protein C for sepsis

Protein C activity as a potential prognostic factor for nursing home-acquired pneumonia

Introduction

Despite the poor prognosis for nursing home acquired pneumonia (NHAP), a useful prognostic factor is lacking. We evaluated protein C (PC) activity as a predictor of in-hospital death in patients with NHAP and community-acquired pneumonia (CAP).

Methods

This prospective, observational study included all patients hospitalized with pneumonia between July 2007 and December 2012 in a single hospital. We measured PC activity at admission and investigated whether it was different between survivors and non-survivors. We also examined whether PC activity < 55% was a predictor for in-hospital death of pneumonia by logistic regression analysis with CURB-65 items (confusion, blood urea >20 mg/dL, respiratory rate >30/min, and blood pressure <90/60 mmHg, age >65). When it was a useful prognostic factor for pneumonia, we combined PC activity with the existing prognostic scores, the pneumonia severity index (PSI) and CURB-65, and analyzed its additional effect by comparing the areas under the receiver operating characteristic curves (AUCs) of the modified and original scores.

Results

Participants comprised 75 NHAP and 315 CAP patients. PC activity was lower among non-survivors than among survivors in NHAP and all-pneumonia (CAP+NHAP). PC activity <55% was a useful prognostic predictor for NHAP (Odds ratio 7.39 (95% CI; 1.59–34.38), and when PSI or CURB-65 was combined with PC activity, the AUC improved (from 0.712 to 0.820 for PSI, and 0.657 to 0.734 for CURB-65).

Conclusions

PC activity was useful for predicting in-hospital death of pneumonia, especially in NHAP, and became more useful when combined with the PSI or CURB-65.

Magnesium Hydride Ameliorates Endotoxin-Induced Acute Respiratory Distress Syndrome by Inhibiting Inflammation, Oxidative Stress, and Cell Apoptosis

Acute respiratory distress syndrome (ARDS) causes uncontrolled pulmonary inflammation, resulting in high morbidity and mortality in severe cases. Given the antioxidative effect of molecular hydrogen, some recent studies suggest the potential use of molecular hydrogen as a biomedicine for the treatment of ARDS. In this study, we aimed to explore the protective effects of magnesium hydride (MgH2) on two types of ARDS models and its underlying mechanism in a lipopolysaccharide (LPS)-induced ARDS model of the A549 cell line. The results showed that LPS successfully induced oxidative stress, inflammatory reaction, apoptosis, and barrier breakdown in alveolar epithelial cells (AEC). MgH2 can exert an anti-inflammatory effect by down-regulating the expressions of inflammatory cytokines (IL-1β, IL-6, and TNF-α). In addition, MgH2 decreased oxidative stress by eliminating intracellular ROS, inhibited apoptosis by regulating the expressions of cytochrome c, Bax, and Bcl-2, and suppressed barrier breakdown by up-regulating the expression of ZO-1 and occludin. Mechanistically, the expressions of p-AKT, p-mTOR, p-P65, NLRP3, and cleaved-caspase-1 were decreased after MgH2 treatment, indicating that AKT/mTOR and NF-κB/NLRP3/IL-1β pathways participated in the protective effects of MgH2. Furthermore, the in vivo study also demonstrated that MgH2-treated mice had a better survival rate and weaker pathological damage. All these findings demonstrated that MgH2 could exert an ARDS-protective effect by regulating the AKT/mTOR and NF-κB/NLRP3/IL-1β pathways to suppress LPS-induced inflammatory reaction, oxidative stress injury, apoptosis, and barrier breakdown, which may provide a potential strategy for the prevention and treatment of ARDS.

Down-regulation of TNF-α via macrophage-targeted RNAi system for the treatment of acute inflammatory sepsis

Sepsis is a systemic inflammatory response syndrome caused by bacterial infection. The sepsis therapy has involved prescription of adequate antibiotics, requiring several days to determine the proper type without reducing the inflammatory response. Thus, it is necessary to rapidly decrease fundamental inflammation, which can induce serious organ damage. In the inflammatory mechanism, tumor necrosis factor-alpha (TNF-α) produced by macrophages has an important role in infiltration of macrophages into infected sites and as a trigger for secretion of pro-inflammatory cytokines. However, commercialized TNF-α antibody medicines have limits such as fibrosis, cytokine storms, and high production costs. There is a growing need for anti-inflammatory sepsis treatment free from side effects. For this reason, TNF-α converting enzyme (TACE) could be an innovative target to break the positive feedback loop of inflammatory mediators (TNF-α) since it converts the inactive TNF-α membrane bound form to the activated soluble form in macrophages. A non-viral gene delivery system was developed in this study to deliver siRNA into inflammation-mediated macrophages without toxicity. The peptide-based gene carrier created by conjugating positively-charged nine arginine (9R) and the TKPR (Thr-Lys-Pro-Arg) sequence from the Fc region of Immunoglobulin G (IgG) specifically binds to the neuropilin-1 (NRP-1) receptor on the macrophage surface. Our results demonstrated that siTACE/TKPR-9R complexes were internalized in macrophages and successfully down-regulated TACE mRNA level. Finally, RNA interference with cell-targeted peptide carriers indicates a fundamental therapy for acute inflammatory sepsis free of off-target effects.

Role of Antithrombin III and Tissue Factor Pathway in the Pathogenesis of Sepsis

The pathobiology of the septic process includes a complex interrelationship between inflammation and the coagulations system. Antithrombin (AT) and tissue factor are important components of the coagulation system and have potential roles in the production and amplification of sepsis. Sepsis is associated with a decrease in AT levels, and low levels are also associated with the development of multiple organ failure and death. Treatment strategies incorporating AT replacement therapy in sepsis and septic shock have not resulted in an improvement in survival or reversal of disseminated intravascular coagulation.

Protective effects of PNU‑282987 on sepsis‑induced acute lung injury in mice

The cholinergic anti‑inflammatory pathway is considered an attractive approach for the alleviation of inflammatory diseases. Sepsis is characterized by systemic inflammation and widespread organ injury, especially that in the lung. In the present study, we explored the effects of an α7nAChR agonist, PNU‑282987, on sepsis‑induced lung injury and investigated the mechanisms of PNU‑282987 in response to lipopolysaccharide (LPS) stimulation in peritoneal macrophages. Sepsis was induced in C57BL/6 mice via cecal ligation puncture (CLP). Fifty mice were randomly divided into five groups: The sham group treated with vehicle, the sham group treated with PNU‑282987, the CLP group treated with vehicle, and the CLP group treated with PNU‑282987 (1 mg/kg) 1 h before or 2 h after surgery. All mice were sacrificed at 12 or 24 h after CLP. Both pre‑ and post‑CLP treatment with PNU‑282987 significantly attenuated sepsis‑induced lung injury and the release of IL‑6 in the bronchoalveolar lavage fluid (BALF). Pre‑treatment with PNU‑282987 also inhibited sepsis‑increased TNF‑α and IL‑6 production, while post‑CLP treatment only inhibited IL‑6 production in the lung tissue. Neither pre‑ nor post‑CLP treatment with PNU‑282987 affected IL‑6 release in the serum. Furthermore, pretreatment with PNU‑282987 resulted in reductions in TNF‑α and IL‑6 release in a dose‑ and time‑dependent manner and decreased the phosphorylation levels of p38, JNK and ERK under LPS conditions in peritoneal macrophages. Our results demonstrate that activation of α7nAChR alleviates sepsis‑induced lung injury; this effect is associated with the suppression of inflammatory responses via the MAPK pathway, suggesting that α7nAChR is a potential therapeutic target for the treatment of sepsis.

The Vitamin E Analog Gamma-Tocotrienol (GT3) and Statins Synergistically Up-Regulate Endothelial Thrombomodulin (TM)

Statins; a class of routinely prescribed cholesterol-lowering drugs; inhibit 3-hydroxy-3-methylglutaryl-coenzymeA reductase (HMGCR) and strongly induce endothelial thrombomodulin (TM); which is known to have anti-inflammatory; anti-coagulation; anti-oxidant; and radioprotective properties. However; high-dose toxicity limits the clinical use of statins. The vitamin E family member gamma-tocotrienol (GT3) also suppresses HMGCR activity and induces TM expression without causing significant adverse side effects; even at high concentrations. To investigate the synergistic effect of statins and GT3 on TM; a low dose of atorvastatin and GT3 was used to treat human primary endothelial cells. Protein-level TM expression was measured by flow cytometry. TM functional activity was determined by activated protein C (APC) generation assay. Expression of Kruppel-like factor 2 (KLF2), one of the key transcription factors of TM, was measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). TM expression increased in a dose-dependent manner after both atorvastatin and GT3 treatment. A combined treatment of a low-dose of atorvastatin and GT3 synergistically up-regulated TM expression and functional activity. Finally; atorvastatin and GT3 synergistically increased KLF2 expression. These findings suggest that combined treatment of statins with GT3 may provide significant health benefits in treating a number of pathophysiological conditions; including inflammatory and cardiovascular diseases.

Coagulopathy and the prognostic potential of D-dimer in hyperlipidemia-induced acute pancreatitis

BACKGROUND

Coagulopathy and its association with disease severity in hyperlipidemia (HL)- and non-hyperlipidemia (NHL)-induced acute pancreatitis (AP) are not clear. The present study was to evaluate the relationship between coagulation homeostasis and AP.

METHODS

This study included 106 AP patients admitted to our hospital between October 2011 and January 2013. Stratified by disease severity, the patients were divided into two groups: a mild AP (MAP) group (n=69); and a moderately severe AP (MSAP) group (n=37). Based on disease etiology, there were 31 HL-induced AP (HLP) cases and 75 NHL-induced AP (NHLP) cases. The HLP and NHLP groups were compared for parameters of coagulation homeostasis, lipid metabolism, and disease severity. Correlations between disease severity and levels of D-dimer and protein C were investigated, and the prognostic potential of D-dimer was evaluated.

RESULTS

Compared with MAP patients, MSAP patients showed higher levels of D-dimer and lower levels of protein C. HLP patients had higher protein C levels than NHLP patients. Both D-dimer and protein C levels were significantly associated with the disease severity, not the disease etiology. D-dimer levels correlated positively with low density lipoprotein cholesterol levels and performed well as a sensitive and specific predictor of disease severity in AP patients, especially in HLP patients.

CONCLUSIONS

The coagulation homeostasis is different between HLP and NHLP patients, and HL may be a contributing factor for thrombosis and fibrinolysis in HLP. D-dimer may be a robust marker of disease severity in HLP.

Kallistatin protects against sepsis-related acute lung injury via inhibiting inflammation and apoptosis

Kallistatin, an endogenous plasma protein, exhibits pleiotropic properties in inhibiting inflammation, oxidative stress and apoptosis, as evidenced in various animal models and cultured cells. Here, we demonstrate that kallistatin levels were positively correlated with the concentration of total protein in bronchoalveolar lavage fluids (BALF) from patients with sepsis-related acute respiratory distress syndrome (ARDS), indicating a compensatory mechanism. Lower ratio of kallistatin to total protein in BALF showed a significant trend toward elevated neutrophil counts (P = 0.002) in BALF and increased mortality (P = 0.046). In lipopolysaccharide (LPS)-treated mice, expression of human kallistatin in lung by gene transfer with human kallistatin-encoding plasmid ameliorated acute lung injury (ALI) and reduced cytokine/chemokine levels in BALF. These mice exhibited attenuated lung epithelial apoptosis and decreased Fas/FasL expression compared to the control mice. Mouse survival was improved by kallistatin gene transfer or recombinant human kallistatin treatment after LPS challenge. In LPS-stimulated A549 human lung epithelial cells, kallistatin attenuated apoptosis, down-regulated Fas/FasL signaling, suppressed intracellular reactive oxygen species (ROS) and inhibited ROS-mediated NF-κB activation and inflammation. Furthermore, LPS-induced apoptosis was blocked by antioxidant N-acetylcysteine or NF-κB inhibitor via down-regulating Fas expression. These findings suggest the therapeutic potential of kallistatin for sepsis-related ALI/ARDS.

Therapeutic interventions in sepsis: current and anticipated pharmacological agents

Sepsis is a clinical syndrome characterized by a multisystem response to a pathogenic assault due to underlying infection that involves a combination of interconnected biochemical, cellular and organ-organ interactive networks. After the withdrawal of recombinant human-activated protein C (rAPC), researchers and physicians have continued to search for new therapeutic approaches and targets against sepsis, effective in both hypo- and hyperinflammatory states. Currently, statins are being evaluated as a viable option in clinical trials. Many agents that have shown favourable results in experimental sepsis are not clinically effective or have not been clinically evaluated. Apart from developing new therapeutic molecules, there is great scope for for developing a variety of drug delivery strategies, such as nanoparticulate carriers and phospholipid-based systems. These nanoparticulate carriers neutralize intracorporeal LPS as well as deliver therapeutic agents to targeted tissues and subcellular locations. Here, we review and critically discuss the present status and new experimental and clinical approaches for therapeutic intervention in sepsis.

Recombinant human annexin A5 inhibits proinflammatory response and improves cardiac function and survival in mice with endotoxemia

OBJECTIVES

Annexin A5 is a 35-kDa protein with high affinity binding to negatively charged phospholipids. However, its effects on sepsis are not known. Our aim was to study the effects of annexin A5 on myocardial tumor necrosis factor-α expression, cardiac function, and animal survival in endotoxemia.

DESIGN

Prospective experimental study.

SETTING

University laboratory.

SUBJECTS

Adult male C57BL/6 mice.

INTERVENTIONS

Mice were challenged with lipopolysaccharide (4 or 20 mg/kg, i.p.) to induce endotoxemia with and without recombinant human annexin A5 treatment (5 or 10 μg/kg, i.v.). Cytokine expression and cardiac function were assessed, and animal survival was monitored.

MEASUREMENTS AND MAIN RESULTS

Treatment with annexin A5 inhibited myocardial mitogen-activated protein kinase, and nuclear factor-κB activation in mice with endotoxemia. Furthermore, annexin A5-treated animals showed significant reductions in myocardial and plasma levels of tumor necrosis factor-α and interleukin-1β while cardiac function was significantly improved during endotoxemia. Additionally, 5-day animal survival was significantly improved by either an immediate or a 4-hour delayed annexin A5 treatment after lipopolysaccharide challenge. Importantly, annexin A5 dose-dependently inhibited lipopolysaccharide binding to a toll-like receptor-4/myeloid differentiation factor 2 fusion protein.

CONCLUSIONS

Annexin A5 treatment decreases cytokine expression and improves cardiac function and survival during endotoxemia. These effects of annexin A5 are mediated by its ability to inhibit lipopolysaccharide binding to toll-like receptor-4, leading to reductions in mitogen-activated protein kinase and Akt signaling. Our study suggests that annexin A5 may have therapeutic potential in the treatment of sepsis.

The Methanol Extract of Azadirachta indica A. Juss Leaf Protects Mice Against Lethal Endotoxemia and Sepsis

In the present study, the inhibitory effect of neem leaf extract (NLE) on lipopolysaccaride (LPS)-induced nitric oxide (NO) and tumor necrosis factor-α (TNF-α) production was examined both in vitro and in vivo. In vitro study revealed that NLE treatment (100 μg/ml) inhibits LPS (100 ng/ml)-induced NO production by 96% and TNF-α production by 32%. The reduction in NO production is probably conferred by the complete suppression of inducible nitric oxide synthase (iNOS) expression. Interestingly, in vivo NLE significantly improved the survival rate of mice in an experimental sepsis model. Administration of NLE (100 mg/kg) 24 h before LPS treatment (20 mg/kg) improved the survival rate of mice by 60%. The inhibition of plasma NO and TNF-α production by NLE is likely to account for the improved survival of mice. Our results suggest that NLE may present a promising avenue in the development of therapeutic agents for the treatment of inflammatory diseases.

Enteral nutritional therapy in septic patients in the intensive care unit: compliance with nutritional guidelines for critically ill patients

OBJECTIVE

Evaluate the compliance of septic patients' nutritional management with enteral nutrition guidelines for critically ill patients.

METHODS

Prospective cohort study with 92 septic patients, age ≥ 18 years, hospitalized in an intensive care unit, under enteral nutrition, evaluated according to enteral nutrition guidelines for critically ill patients, compliance with caloric and protein goals, and reasons for not starting enteral nutrition early or for discontinuing it. Prognostic scores, length of intensive care unit stay, clinical progression, and nutritional status were also analyzed.

RESULTS

The patients had a mean age of 63.4 ± 15.1 years, were predominantly male, were diagnosed predominantly with septic shock (56.5%), had a mean intensive care unit stay of 11 (7.2 to 18.0) days, had 8.2 ± 4.2 SOFA and 24.1 ± 9.6 APACHE II scores, and had 39.1% mortality. Enteral nutrition was initiated early in 63% of patients. Approximately 50% met the caloric and protein goals on the third day of intensive care unit stay, a percentage that decreased to 30% at day 7. Reasons for the late start of enteral nutrition included gastrointestinal tract complications (35.3%) and hemodynamic instability (32.3%). Clinical procedures were the most frequent reason to discontinue enteral nutrition (44.1%). There was no association between compliance with the guidelines and nutritional status, length of intensive care unit stay, severity, or progression.

CONCLUSION

Although the number of septic patients under early enteral nutrition was significant, caloric and protein goals at day 3 of intensive care unit stay were met by only half of them, a percentage that decreased at day 7.

Therapeutic modulation of coagulation and fibrinolysis in acute lung injury and the acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) are characterized by excessive intraalveolar fibrin deposition, driven, at least in part by inflammation. The imbalance between activation of coagulation and inhibition of fibrinolysis in patients with ALI/ARDS favors fibrin formation and appears to occur both systemically and in the lung and airspace. Tissue factor (TF), a key mediator of the activation of coagulation in the lung, has been implicated in the pathogenesis of ALI/ARDS. As such, there have been numerous investigations modulating TF activity in a variety of experimental systems in order to develop new therapeutic strategies for ALI/ARDS. This review will summarize current understanding of the role of TF and other proteins of the coagulation cascade as well the fibrinolysis pathway in the development of ALI/ARDS with an emphasis on the pathways that are potential therapeutic targets. These include the TF inhibitor pathway, the protein C pathway, antithrombin, heparin, and modulation of fibrinolysis through plasminogen activator- 1 (PAI-1) or plasminogen activators (PA). Although experimental studies show promising results, clinical trials to date have proven unsuccessful in improving patient outcomes. Modulation of coagulation and fibrinolysis has complex effects on both hemostasis and inflammatory pathways and further studies are needed to develop new treatment strategies for patients with ALI/ARDS.

Recombinant human activated protein C for severe sepsis in neonates

BACKGROUND

Sepsis is a common problem in preterm and term infants. The incidence of neonatal sepsis has declined, but mortality remains high. Recombinant human activated protein C (rhAPC) possess a broad spectrum of activity modulating coagulation and inflammation. In septic adults it may reduce mortality, but no significant benefit has been reported in children with severe sepsis.

OBJECTIVES

To determine whether treatment with rhAPC reduces mortality and/or morbidity in neonatal sepsis.

SEARCH METHODS

For this update searches were carried out in May 2011 of the Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and abstracts of annual meetings of the Pediatric Academic Societies. Doctoral dissertations, theses and the Science Citation Index for articles on activated protein C were searched. No language restriction was applied.

SELECTION CRITERIA

Randomized or quasi-randomized trials, assessing the efficacy of rhAPC compared to placebo or no intervention as an adjunct to antibiotic therapy of suspected or confirmed severe sepsis in term and preterm infants less than 28 days old. Eligible trials should report at least one of the following outcomes: mortality during initial hospital stay, neurodevelopmental assessment at two years of age or later, length of hospital stay, duration of ventilation, chronic lung disease, periventricular leukomalacia, intraventricular haemorrhage, necrotizing enterocolitis, bleeding, and any other adverse events.

DATA COLLECTION AND ANALYSIS

Review authors were to independently evaluate the articles for inclusion criteria and quality, and abstract information for the outcomes of interest. Differences were to be resolved by consensus. The statistical methods were to include relative risk, risk difference, number needed to treat to benefit or number needed to treat to harm for dichotomous and weighed mean difference for continuous outcomes reported with 95% confidence intervals. A fixed effect model was to be used for meta-analysis. Heterogeneity tests, including the I(2) statistic, were to be performed to assess the appropriateness of pooling the data.

MAIN RESULTS

No eligible trials were identified. In October 2011 rhAPC (Xigris®) was withdrawn from the market by Eli Lilly due to a higher mortality in a trial among adults. Xigris® (DrotAA)( rhAPC) should no longer be used in any age category and the product should be returned to the distributor.

AUTHORS' CONCLUSIONS

Despite the scientific rationale for its use, there is insufficient data to use rhAPC for the management of severe sepsis in newborn infants. Due to the results among adults with lack of efficacy, an increase in bleeding and resulting withdrawal of rhAPC from the market, neonates should not be treated with rhAPC and further trials should not be conducted.

Knowledge and therapeutic gaps: a public health problem in the rare coagulation disorders population

Rare coagulation disorders (RCDs) present a considerable and multifaceted public health risk. Although inherited RCDs affect a minor segment of any local healthcare delivery system, their global impact is major and highlight the challenges of delivering healthcare services to any rare disease population. These include but are not limited to: (1) a general lack of knowledge about and familiarity with the genetic and clinical implications of the disorder among affected patients, and both urgent and specialty care providers; (2) the potential for preventable morbidity and mortality related to delayed diagnosis and treatment; (3) the lack of safe and effective therapies; and (4) minimal research activity to establish and improve standards of care. A multiagency national partnership has established an approach to address these problems through development of a clinical, genetic, and treatment-related web-based data-collection tool that will: (1) generate a reliable, sufficient knowledge base for these disorders; (2) facilitate new product licensure through subject identification and access to comparative historical treatment data; and (3) serve as an effective tool for outcomes research and post-licensure product surveillance. To maximize impact, this database is being harmonized with a European data-collection effort. Database development and harmonization is in progress. A resource library was completed and disseminated to major national and international bleeding disorder websites to provide state-of-the-art patient and provider education on each RCD. We believe that this model is effective and adaptable to other rare conditions.

Systemic inflammation in the elderly

Inflammation is an adaptive response to surgery. When the pro-inflammatory responses are unregulated and become over reactive, systemic inflammatory response syndrome may occur. Postoperative systemic inflammation is more common than is generally acknowledged and is observed in about 10-15% of elderly patients undergoing major surgery. Although the vast majority of systemic inflammation is related to infections, other important predisposing risk factors, such as extent of trauma and haemorrhage, should not be overlooked. Increased awareness, modification of risk factors and early recognition are the key elements in the management of systemic inflammation. Prompt resuscitation aiming to correct hypotension, hypovolaemia and tissue hypoxia may improve outcome. Future large prospective observational studies are needed to define the incidence, risk factors and impact of systemic inflammatory syndrome in the elderly surgical patients. A better understanding of the molecular events during the systemic inflammatory response syndrome is required for future development of specific immunotherapy.

Endothelial activation, dysfunction and permeability during severe infections

PURPOSE OF REVIEW

Over the last few years, there have been major advances in our understanding of the role of the microvascular endothelium in the pathogenesis of severe, systemic infections.

RECENT FINDINGS

Endothelial activation and dysfunction contribute directly to the morbidity and mortality of sepsis and other, severe systemic infections. The end-result of diffuse endothelial activation and dysfunction may be the loss of microvascular barrier integrity, leading to tissue edema, shock and multiple organ failure. Endothelial activation also leads to an increase in angiopoietin-2, which is known to destabilize barrier function and promote inflammation.

SUMMARY

The ratio of the secreted endothelial growth factors, angiopoietin-2 and angiopoietin-1 appears to be a useful prognostic tool during severe infections. Finally, agents that enhance endothelial barrier integrity may prove useful as therapies for sepsis.

The resuscitation package in sepsis

Sepsis and its attendant complications are commonly encountered in the intensive care unit. Early recognition of sepsis is critical because it allows for rapid deployment of a multifaceted resuscitation package. The cornerstones of sepsis management are antibiotic therapy, source control, and hemodynamic resuscitation. In select patients, ancillary therapies are indicated, such as activated protein C, corticosteroids, and glycemic control. Given the complexity of sepsis management, optimal care can be delivered as a bundle-a protocol encompassing the above interventions. The evidence behind the various components of sepsis management are reviewed here.

Proteases as therapeutics

Proteases are an expanding class of drugs that hold great promise. The U.S. FDA (Food and Drug Administration) has approved 12 protease therapies, and a number of next generation or completely new proteases are in clinical development. Although they are a well-recognized class of targets for inhibitors, proteases themselves have not typically been considered as a drug class despite their application in the clinic over the last several decades; initially as plasma fractions and later as purified products. Although the predominant use of proteases has been in treating cardiovascular disease, they are also emerging as useful agents in the treatment of sepsis, digestive disorders, inflammation, cystic fibrosis, retinal disorders, psoriasis and other diseases. In the present review, we outline the history of proteases as therapeutics, provide an overview of their current clinical application, and describe several approaches to improve and expand their clinical application. Undoubtedly, our ability to harness proteolysis for disease treatment will increase with our understanding of protease biology and the molecular mechanisms responsible. New technologies for rationally engineering proteases, as well as improved delivery options, will expand greatly the potential applications of these enzymes. The recognition that proteases are, in fact, an established class of safe and efficacious drugs will stimulate investigation of additional therapeutic applications for these enzymes. Proteases therefore have a bright future as a distinct therapeutic class with diverse clinical applications.

Inflammation and coagulation. An overview

Inflammation and coagulation are two main host-defence systems that interact with each other. Inflammation activates coagulation and coagulation modulates the inflammatory activity in many ways. The contributing molecular pathways are reviewed. Thrombin and activated protein C (APC) and its receptor EPCR constitute a major physiological regulatory system to control vascular wall permeability during sepsis. Pro-inflammatory cellular effects of coagulation proteases as well as the anti-inflammatory effects of APC/EPCR are mediated by signaling via protease activated receptors PAR on mononuclear cells, endothelial cells, platelets, fibroblast, and smooth muscle cells. The beneficial effects of APC in sepsis are mainly dependent on the PAR-mediated cell-protective properties rather than the anticoagulant protease function on coagulation cofactors FV/Va and FVIII/VIIIa. Animal experiments with signaling selective APC-variants show promise in improving the therapeutic efficacy and safety of APC in sepsis.

Activated protein C up-regulates procoagulant tissue factor activity on endothelial cells by shedding the TFPI Kunitz 1 domain

Thrombin and activated protein C (APC) signaling can mediate opposite biologic responses in endothelial cells. Given that thrombin induces procoagulant tissue factor (TF), we examined how TF activity is affected by APC. Exogenous or endogenously generated APC led to increased TF-dependent factor Xa activity. Induction required APC's proteolytic activity and binding to endothelial cell protein C receptor but not protease activated receptors. APC did not affect total TF antigen expression or the availability of anionic phospholipids on the apical cell membrane. Western blotting and cell surface immunoassays demonstrated that APC sheds the Kunitz 1 domain from tissue factor pathway inhibitor (TFPI). A TFPI Lys86Ala mutation between the Kunitz 1 and 2 domains eliminated both cleavage and the enhanced TF activity in response to APC in overexpression studies, indicating that APC up-regulates TF activity by endothelial cell protein C receptor-dependent shedding of the Kunitz 1 domain from membrane-associated TFPI. Our results demonstrate an unexpected procoagulant role of the protein C pathway that may have important implications for the regulation of TF- and TFPI-dependent biologic responses and for fine tuning of the hemostatic balance in the vascular system.

New modalities in treating pneumococcal pneumonia

Despite the availability of effective antibiotics and intensive medical care, pneumococcal pneumonia is still associated with substantial mortality. Early diagnosis is becoming increasingly possible. This article reviews several adjunctive measures that might be instituted at or soon after admission in patients who are hospitalized for community-acquired pneumonia that is found to be due to Streptococcus pneumoniae. Available data favor the use of a macrolide together with a β-lactam antibiotic for treatment, based largely on immunomodulatory activity of macrolides. Two large subgroup analyses from a single major study suggest that activated protein C (eg, drotrecogin) should be considered for patients with severe sepsis, organ failure, and an Acute Physiology and Chronic Health Evaluation II score > 25 due to pneumococcal pneumonia. Statins exert an anti-inflammatory effect and several retrospective studies suggest that their use might ameliorate the adverse effects of pneumonia. Because inflammation elsewhere in the body is associated with inflammation in coronary arteries and because pneumococcal pneumonia has been shown to precipitate myocardial infarction, statins might be of further benefit by decreasing the likelihood of associated myocardial infarction. Aspirin, which inhibits platelet aggregation in inflamed coronary arteries, might also be considered for initial therapy. One reason that the association between myocardial infarction and pneumonia was not previously recognized is that aspirin was widely used in the past when people had acute febrile conditions. The literature on the benefits of corticosteroids in pneumonia is not convincing, and a particularly well-done, very recent study shows no benefit with corticosteroid use in patients with pneumococcal pneumonia, and perhaps even a worse outcome. No clinical data favor the use of platelet-activating factor antagonists.

Established and novel biomarkers of sepsis

The increased incidence of sepsis, a systemic response to infection that occurs in some patients, has stimulated interest in identifying infected patients who are at risk and intervening early. When this condition progresses to severe sepsis (characterized by organ dysfunction), mortality is high. Hospitals that have implemented recommendations of the Surviving Sepsis Campaign have seen a reduction in mortality rate for hospital-acquired severe sepsis. They may reduce this further by focusing on new approaches to diagnosing sepsis, especially at an early stage. Sepsis is a complicated syndrome with many physiological derangements and many emerging laboratory markers of sepsis have been proposed as adjuncts to clinical evaluation. The list includes cytokines, acute phase proteins, neutrophil activation markers, markers of abnormal coagulation and, recently, markers of suppression of both the innate and adaptive immune response. The perfect biomarker would accurately identify patients at risk of developing severe sepsis and then guide targeted therapy.

Upregulation of Microparticles in DIC and its Impact on Inflammatory Processes

Disseminated intravascular coagulation (DIC) results in the catastrophic simultaneous activation of thrombotic and hemorrhagic processes. Its pathophysiology and the role of inflammation and microparticles (MPs) are not fully understood. Microparticles represent small phospholipid-expressing procoagulant vesicular fragments, released with cellular disruption and apoptosis. Functional MPs were measured in 100 random patients from a population of patients with DIC. Plasma samples from 30 normal male and female volunteers were used as control. Commercial Annexin trapping method was used to determine procoagulant activity of MPs. Mean ± SD concentration of MPs in the DIC group was 24.6 ± 14.2 nmol/L (range: 0.0-60.0 nmol/L), significantly higher than the control group: 8.5 ± 4.3 nmol/L (range: 1.3-17.4 nmol/L). Distribution curves and scattergrams showed that MPs concentration in the DIC samples was more widespread. This demonstrates that MPs are upregulated in patients with DIC and may mediate the hemostatic activation and inflammatory responses in this syndrome.

Lack of effect of oral administration of resveratrol in LPS-induced systemic inflammation

PURPOSE

The high mortality index due to sepsis and the lack of an effective treatment requires the search for new compounds that can serve as therapy for this disease. Resveratrol, a well-known anti-inflammatory natural compound, might be a good candidate for the treatment of sepsis. The aim of this work was to study the effects of oral administration of resveratrol, before and after sepsis initiation, on inflammation markers in a murine model of endotoxin-induced sepsis.

METHODS

Sprague-Dawley male rats were treated with resveratrol the 3 days prior to LPS administration and 45 min later. Hematological parameters, TNF-α, IL-1β and CINC-1, FRAP and TBARS levels were determined. Resveratrol and resveratrol-derived metabolites profile in plasma was compared after oral and intraperitoneal administration.

RESULTS

Oral treatment with resveratrol had no apparent systemic protective effects. However, resveratrol reduced the levels of lipid peroxidation in the small intestine and colon. Importantly, the administration of LPS caused a decrease in resveratrol absorption. When resveratrol bioavailability after i.p. administration was compared to that observed after oral administration, a different profile of resveratrol metabolites was found in plasma.

CONCLUSION

These results highlight the importance of studying the bioavailability of the assayed compounds in the experimental models used to be able to choose the best route of administration depending on the target organ and to determine which compounds or derived metabolites are effective treating the studied disease.

Tryptophan degradation and serum neopterin concentrations in intensive care unit patients

Alterations in neopterin concentrations and tryptophan degradation accompany the activation of cellular immune systems. Accordingly, in a variety of diseases, mainly in infections, elevated neopterin levels and tryptophan degradation have been observed. This study aimed to assess serum neopterin levels and tryptophan degradation in intensive care unit (ICU) patients with systemic inflammatory response syndrome (SIRS, n = 9), sepsis (n = 8), septic shock (n = 10), and multiple organ dysfunction syndrome (MODS, n = 7) at the first day of ICU hospitalization. The kynurenine-to-tryptophan (kyn/trp) ratio was used in order to evaluate the degree of tryptophan degradation. The results of each patient group were compared with the control group (n = 30). The differences among the ICU groups and the correlations between APACHE II scores and neopterin concentrations or tryptophan degradation were investigated. All patient groups presented statistically higher kyn/trp and neopterin levels than the controls. The sepsis, septic shock, and MODS group had markedly higher neopterin levels than the SIRS group (all P < 0.05). Additionally, it was found that the survivor group had significantly lower neopterin levels compared with non-survivors (P < 0.05) and lower kyn/trp, but the latter difference was not significant. Neopterin levels and kyn/trp were both correlated with APACHE II score (both P < 0.05). The results indicate that serum neopterin levels and tryptophan degradation correlate well with the severity of the disease in ICU patients, and this was true even at the first day of hospitalization in the unit.

How I manage haematology patients with septic shock

Patients with a variety of haematological conditions are at risk of infection and its most serious complication: septic shock. Mortality for septic shock remains high and especially so in patients with haematological malignancy and following bone marrow transplantation. However, advances in the treatment of severe sepsis have improved mortality rates even though evidence for the management of severe sepsis in haematology patients is limited. Wherever possible this review will concentrate on evidence directly applicable to haematology patients but inevitably will have to extrapolate evidence from other patient groups. The Surviving Sepsis Guidelines 2008 provide information on best practice in the management of patients with severe sepsis and septic shock and are broadly applicable though not specific to haematology patients. This review summarizes a practical approach to the management of severe sepsis in haematology patients and highlights areas of research which may bring new treatments in the future. The review is limited to the management and initial resuscitation of septic shock in adult haematology patients and will not address the detailed intensive care management of these patients or the management of severe sepsis in children.

Managing septic shock

Although several successful clinical trials in the last 2-3 years have been greeted with enthusiasm by intensivists, severe sepsis and septic shock still have increasing incidence and more or less unchanged mortality. Within the last few years, the progress in sepsis research covering definitions, epidemiology, pathophysiology, diagnosis, and standard and adjunctive therapy as well as general measures such as treatment bundles is encouraging. In this report, a small selection of recent publications, focusing on the current discussion of activated protein C as well as the relevance of the Surviving Sepsis Campaign bundle therapy, is presented and the possible impact on clinical routine is discussed.

An unusual cause of multiple cerebral hemorrhages: drotrecogin alpha (activated protein C)

The mortality of severe sepsis is still high, despite improved treatment modalities. It is known that treatment with DAA reduces mortality in this condition; however, major bleeding may occur as a complication. We present a patient with normal findings on platelet and coagulation tests who developed multiple cerebral hemorrhages after DAA infusion. Patients with septic shock who undergo DAA infusion should be followed closely for possible intracranial bleeding. When intracranial hemorrhage is detected in patients in the intensive care unit, treatment with DAA infusion should be questioned.