Interleukin 6 is a prognostic indicator of outcome in severe intra-abdominal sepsis

Efficacy of taurine-enhanced enteral nutrition in improving the outcomes of critically ill patients: A systematic review and meta-analysis

BACKGROUND

Taurine is considered an immunomodulatory agent. From current reports on clinical studies, we conducted a systematic review and meta-analysis to investigate the effects of taurine-enhanced enteral nutrition (EN) on the outcomes of critically ill patients to resolve conflicting evidence in literature.

METHODS

Literature from PubMed, EMBASE, Web of Science, Cochrane Library, CNKI, SINOMED, and WanFang databases were retrieved, and randomized controlled trials (RCTs) were identified. The time range spanned from January 1, 2000, to January 31, 2024. The Cochrane Collaboration Tool was used to evaluate the risk of bias. We used the GRADE approach to rate the quality of evidence and the I2 test to assess the statistical heterogeneity of the results. Risk ratio (RR), mean difference (MD), and 95% confidence interval (95% CI) were used to analyze measurement data.

RESULTS

Four trials involving 236 patients were finally included. The meta-analysis results indicated that taurine-enhanced EN did not reduce mortality (RR = 0.70, p = 0.45, 95% CI [0.28, 1.80], two trials, 176 participants, low quality). There was also no significant difference in length of stay in the intensive care unit (ICU) between the taurine-enhanced EN and control groups. Taurine-enhanced EN may reduce pro-inflammatory factor interleukin-6 (IL-6) levels in critically ill patients（the result about IL-6 cannot be pooled）. However, taurine-enhanced EN had no significant impact on high-sensitivity-C-reactive protein levels (MD = -0.41, p = 0.40, 95% CI [-1.35, 0.54], two trials, 60 participants, low quality).

DISCUSSION

Taurine-enhanced EN may reduce IL-6 levels and is not associated with improved clinical outcomes in critically ill patients, which may have potential immunoregulatory effects in critically ill patients. Given that published studies have small samples, the above conclusions need to be verified by more rigorously designed large-sample clinical trials.

Adverse outcomes and an immunosuppressed endotype in septic patients with reduced IFN-γ ELISpot

BACKGROUNDSepsis remains a major clinical challenge for which successful treatment requires greater precision in identifying patients at increased risk of adverse outcomes requiring different therapeutic approaches. Predicting clinical outcomes and immunological endotyping of septic patients generally relies on using blood protein or mRNA biomarkers, or static cell phenotyping. Here, we sought to determine whether functional immune responsiveness would yield improved precision.METHODSAn ex vivo whole-blood enzyme-linked immunosorbent spot (ELISpot) assay for cellular production of interferon γ (IFN-γ) was evaluated in 107 septic and 68 nonseptic patients from 5 academic health centers using blood samples collected on days 1, 4, and 7 following ICU admission.RESULTSCompared with 46 healthy participants, unstimulated and stimulated whole-blood IFN-γ expression was either increased or unchanged, respectively, in septic and nonseptic ICU patients. However, in septic patients who did not survive 180 days, stimulated whole-blood IFN-γ expression was significantly reduced on ICU days 1, 4, and 7 (all P < 0.05), due to both significant reductions in total number of IFN-γ-producing cells and amount of IFN-γ produced per cell (all P < 0.05). Importantly, IFN-γ total expression on days 1 and 4 after admission could discriminate 180-day mortality better than absolute lymphocyte count (ALC), IL-6, and procalcitonin. Septic patients with low IFN-γ expression were older and had lower ALCs and higher soluble PD-L1 and IL-10 concentrations, consistent with an immunosuppressed endotype.CONCLUSIONSA whole-blood IFN-γ ELISpot assay can both identify septic patients at increased risk of late mortality and identify immunosuppressed septic patients.TRIAL REGISTRYN/A.FUNDINGThis prospective, observational, multicenter clinical study was directly supported by National Institute of General Medical Sciences grant R01 GM-139046, including a supplement (R01 GM-139046-03S1) from 2022 to 2024.

Adverse Long-Term Outcomes and an Immune Suppressed Endotype in Sepsis Patients with Reduced Interferon-γELISpot: A Multicenter, Prospective Observational Study

BACKGROUND

Sepsis remains a major clinical challenge for which successful treatment requires greater precision in identifying patients at increased risk of adverse outcomes requiring different therapeutic approaches. Predicting clinical outcomes and immunological endotyping of septic patients has generally relied on using blood protein or mRNA biomarkers, or static cell phenotyping. Here, we sought to determine whether functional immune responsiveness would yield improved precision.

METHODS

An ex vivo whole blood enzyme-linked immunosorbent (ELISpot) assay for cellular production of interferon-γ (IFN-γ) was evaluated in 107 septic and 68 non-septic patients from five academic health centers using blood samples collected on days 1, 4 and 7 following ICU admission.

RESULTS

Compared with 46 healthy subjects, unstimulated and stimulated whole blood IFNγ expression were either increased or unchanged, respectively, in septic and nonseptic ICU patients. However, in septic patients who did not survive 180 days, stimulated whole blood IFNγ expression was significantly reduced on ICU days 1, 4 and 7 (all p<0.05), due to both significant reductions in total number of IFNγ producing cells and amount of IFNγ produced per cell (all p<0.05). Importantly, IFNγ total expression on day 1 and 4 after admission could discriminate 180-day mortality better than absolute lymphocyte count (ALC), IL-6 and procalcitonin. Septic patients with low IFNγ expression were older and had lower ALC and higher sPD-L1 and IL-10 concentrations, consistent with an immune suppressed endotype.

CONCLUSIONS

A whole blood IFNγ ELISpot assay can both identify septic patients at increased risk of late mortality, and identify immune-suppressed, sepsis patients.

A matched case-control study on the effectiveness of extracorporeal cytokine adsorption in critically ill patients

Extracorporeal cytokine adsorption aims to reduce cytokine levels in critically ill patients. However, little convincing data exist to support its widespread use. This retrospective study compared interleukin-6 (IL-6) levels in patients treated with or without cytokine adsorber (CytoSorb®). Intensive care patients between Jan 2017 and Dec 2021 who had at least two IL-6 measurements were included. They were divided into an adsorber group and a standard of care group. We screened 3865 patients and included 52 patients in the adsorber group and 94 patients in the standard of care group. Matching was performed and the groups were compared regarding IL-6, lactate, CRP, procalcitonin, vasopressor requirement, and mortality rate. After matching, there were 21 patients in each group. Patients had similar age, ECMO and renal replacement therapy use, baseline noradrenaline requirement, serum lactate, pH, CRP, and IL-6 levels. There were no significant differences in the time course of IL-6, lactate, CRP, procalcitonin and noradrenaline requirement between groups. Two-day and ICU mortality and Kaplan-Meier estimated survival were also comparable. In this matched case-control study no difference in IL-6, inflammatory parameters, noradrenaline requirement or mortality was observed between patients treated with adsorber or standard of care.

BACTERIOPHAGE M13 MODULATES THE SEPSIS-RELATED INFLAMMATORY RESPONSES AND ORGAN DAMAGE IN A CLP MODEL

ABSTRACT

Background: Sepsis is a life-threatening disorder that leads to the induction of inflammatory responses and organ failure. Phage therapy is a new approach to controlling infections resistant to common treatments, including sepsis. Several studies have shown the effect of lytic bacteriophages on infection control by reducing the bacterial load. The present study deals with lysogenic bacteriophage M13 on the inflammatory responses caused by cecal ligation and puncture (CLP)-induced sepsis in a mouse model. Methods Bacteriophage M13 harvested from ER2738, titrated, and confirmed by transmission electron microscopy analysis. In vitro toxicity and immunomodulatory effect of bacteriophage M13 were assessed on splenocytes by measurement of cell viability and the production level of cytokines, nitric oxide, and reactive oxygen species. For in vivo experiments, 8-weeks-old male C57BL/6 mice were randomly divided into the following three groups: CLP + NS (treated with normal saline), CLP + M13 (treated with an intraperitoneal injection of 10 9 PFU/mL of bacteriophage M13), and sham + NS (induced surgery but without ligation and puncture, treated with NS). The mice were killed at different time points after surgery (6, 24, 48, and 72, n = 10 for each time point of each group). The kidney, liver, and lungs were harvested for histopathological analysis, and blood was obtained for cytokine and liver enzyme assay. The spleen was used to assess the bacterial load using colony-forming unit assay. The rectal temperature and survival were evaluated during the study. Results According to the in vitro results, 10 9 PFU/mL of bacteriophage M13 was not toxic and did not affect the level of cytokine, nitric oxide, and reactive oxygen species production by splenocytes, but it reduced the inflammatory response of splenocytes in responses to LPS. In vivo studies indicated that the amount of proinflammatory cytokines, liver enzymes, bacterial load, and organ failure were decreased in the CLP + M13 group compared with CLP + NS, whereas the survival rate was increased. Conclusions These experiments demonstrated that bacteriophage M13 could lessen the consequences related to sepsis in CLP mice and can be considered a therapeutic approach in sepsis.

A new approach to sepsis treatment by rasagiline: a molecular, biochemical and histopathological study

AIM

We aimed to investigate the effects of rasagiline on acute lung injury that develops in the sepsis model induced with the cecal ligation and puncture in rats.

MAIN METHODS

The rats were separated into the following six groups, Group 1: Sham, Group 2: Sham + Rasagiline 4 mg/kg, Group 3: Sepsis, Group 4: Sepsis + Rasagiline 1 mg/kg, Group 5: Sepsis + Rasagiline 2 mg/kg, Group 6: Sepsis + Rasagiline 4 mg/kg. A total of four holes were opened with a 16-gauge needle through the cecum distal to the point of ligation.

KEY FINDINGS

Rasagiline treatment increased glutathione level and superoxide dismutase activity while decreased the malondialdehyde level after the sepsis. There was a statistically significant improvement in the doses of 2 mg/kg and 4 mg/kg. Rasagiline also increased Tnf-α, IL1β, IL6, NF-κβand HMGB1 gene expressions in dose-dependent at 2 mg/kg and 4 mg/kg doses. In increased doses, rasagiline prevent the development of edema, the formation of inflammation, and hemorrhage.

SIGNIFICANCE

Rasagiline exerts both antioxidant and anti-inflammatory effects on the cecal ligation and puncture induced acute lung injury in rats.

Aryl Hydrocarbon Receptor Activation by Benzo[a]pyrene Prevents Development of Septic Shock and Fatal Outcome in a Mouse Model of Systemic Salmonella enterica Infection

This study focused on immunomodulatory effects of aryl hydrocarbon receptor (AhR) activation through benzo[a]pyrene (BaP) during systemic bacterial infection. Using a well-established mouse model of systemic Salmonella enterica (S.E.) infection, we studied the influence of BaP on the cellular and humoral immune response and the outcome of disease. BaP exposure significantly reduced mortality, which is mainly caused by septic shock. Surprisingly, the bacterial burden in BaP-exposed surviving mice was significantly higher compared to non-exposed mice. During the early phase of infection (days 1-3 post-infection (p.i.)), the transcription of proinflammatory factors (i.e., IL-12, IFN-γ, TNF-α, IL-1β, IL-6, IL-18) was induced faster under BaP exposure. Moreover, BaP supported the activity of antigen-presenting cells (i.e., CD64 (FcγRI), MHC II, NO radicals, phagocytosis) at the site of infection. However, early in infection, the anti-inflammatory cytokines IL-10 and IL-22 were also locally and systemically upregulated in BaP-exposed S.E.-infected mice. BaP-exposure resulted in long-term persistence of salmonellae up to day 90 p.i., which was accompanied by significantly elevated S.E.-specific antibody responses (i.e., IgG1, IgG2c). In summary, these data suggest that BaP-induced AhR activation is capable of preventing a fatal outcome of systemic S.E. infection, but may result in long-term bacterial persistence, which, in turn, may support the development of chronic inflammation.

Early Elevation of Thioredoxin-1 Serum Levels Predicts 28-Day Mortality in Patients with Sepsis

Background

Sepsis is the leading cause of death in critically ill patients, and the prevention of which requires precise outcome prediction and early intervention. We evaluated the prognostic prediction value of serum thioredoxin-1 (Trx-1) as an anti-inflammatory factor in patients with sepsis.

Methods

As a prospective study, patients with sepsis admitted to the intensive care unit (ICU) of our hospital during 2020 were recruited. Medical history collection, sequential organ failure assessment (ΔSOFA), and laboratory tests were performed within 24 h of admission. Serum levels of Trx-1 and other inflammatory biomarkers were detected with samples dynamically collected before, during, and after septic shock. Patients were categorized as survivors and non-survivors according to survival status on day 28. Correlation between Trx-1 and other sepsis-associated parameters as well as the correlation of Trx-1 and other sepsis-associated parameters with 28-day mortality were evaluated. Prognostic factors were identified by Cox regression analyses.

Results

A total of 187 patients were recruited. Serum Trx-1 level was positively correlated with inflammatory factors (interleukin-6, C-reactive protein, procalcitonin) and index of sepsis severity (ΔSOFA score, partial pressure of oxygen/fraction of inspired oxygen), all of which were significantly higher in non-survivors than survivors. While Trx-1 level at different timepoints and its evolution over time significantly differed between survivors and non-survivors, the initial Trx-1 level outperformed the other parameters in predicting 28-day survival. With 38.27 ng/mL as the cutoff value, serum Trx-1 predicted 28-day survival with optimal sensitivity and specificity.

Conclusion

Early increases in serum levels of Trx-1 can predict 28-day mortality in sepsis patients in the ICU.

Biomarker-Guided Individualization of Antibiotic Therapy

Treatment failure of antibiotic therapy due to insufficient efficacy or occurrence of toxicity is a major clinical challenge, and is expected to become even more urgent with the global rise of antibiotic resistance. Strategies to optimize treatment in individual patients are therefore of crucial importance. Currently, therapeutic drug monitoring plays an important role in optimizing antibiotic exposure to reduce treatment failure and toxicity. Biomarker-based strategies may be a powerful tool to further quantify and monitor antibiotic treatment response, and reduce variation in treatment response between patients. Host response biomarkers, such as CRP, procalcitonin, IL-6, and presepsin, could potentially carry significant information to be utilized for treatment individualization. To achieve this, the complex interactions among immune system, pathogen, drug, and biomarker need to be better understood and characterized. The purpose of this tutorial is to discuss the use and evidence of currently available biomarker-based approaches to inform antibiotic treatment. To this end, we also included a discussion on how treatment response biomarker data from preclinical, healthy volunteer, and patient-based studies can be further characterized using pharmacometric and system pharmacology based modeling approaches. As an illustrative example of how such modeling strategies can be used, we describe a case study in which we quantitatively characterize procalcitonin dynamics in relation to antibiotic treatments in patients with sepsis.

Aptamer-based biosensors for the diagnosis of sepsis

Sepsis, the syndrome of infection complicated by acute organ dysfunction, is a serious and growing global problem, which not only leads to enormous economic losses but also becomes one of the leading causes of mortality in the intensive care unit. The detection of sepsis-related pathogens and biomarkers in the early stage plays a critical role in selecting appropriate antibiotics or other drugs, thereby preventing the emergence of dangerous phases and saving human lives. There are numerous demerits in conventional detection strategies, such as high cost, low efficiency, as well as lacking of sensitivity and selectivity. Recently, the aptamer-based biosensor is an emerging strategy for reasonable sepsis diagnosis because of its accessibility, rapidity, and stability. In this review, we first introduce the screening of suitable aptamer. Further, recent advances of aptamer-based biosensors in the detection of bacteria and biomarkers for the diagnosis of sepsis are summarized. Finally, the review proposes a brief forecast of challenges and future directions with highly promising aptamer-based biosensors.

Effects of Neutrophil-to-Lymphocyte Ratio Combined With Interleukin-6 in Predicting 28-Day Mortality in Patients With Sepsis

Background

The current study aimed to evaluate the relationship between the neutrophil-to-lymphocyte ratio (NLR) combined with interleukin (IL)-6 on admission day and the 28-day mortality of septic patients.

Material and Methods

We conducted an observational retrospective study. Patients with presumed sepsis were included. We observed the correlation of studied biomarkers (NLR, IL-6, PCT, and CRP) and the severity scores (APACHE II and SOFA scores) by plotting scatter plots. The relationships of the studied biomarkers and 28-day mortality were evaluated by using Cox regression model, receiver-operating characteristic (ROC) curve, and reclassification analysis.

Results

A total of 264 patients diagnosed with sepsis were enrolled. It was revealed that IL-6 had the strongest correlation with both APACHE II and SOFA scores, followed by the NLR and PCT, and there was no obvious correlation between CRP and the illness severity. NLR and IL-6 were independent predictors of the 28-day mortality in septic patients in the Cox regression model [NLR, odds ratio 1.281 (95% CI 1.159-1.414), P < 0.001; IL-6, odds ratio 1.017 (95% CI 1.005-1.028), P=0.004]. The area under the ROC curve (AUC) of NLR, IL-6 and NLR plus IL-6 (NLR_IL-6) was 0.776, 0.849, and 0.904, respectively.

Conclusion

Our study showed that the levels of NLR and IL-6 were significantly higher in the deceased patients with sepsis. NLR and IL-6 appeared to be independent predictors of 28-day mortality in septic patients. Moreover, NLR combined with IL-6 could dramatically enhance the prediction value of 28-day mortality.

Imipenem alters systemic and liver inflammatory responses in CLP- induced sepsis mice in a dose-dependent manner

BACKGROUND

Considering the role of inflammation in the outcome of sepsis and the widespread use of imipenem in the disease, this study was designed to assess the effect of imipenem on the dynamics of inflammatory responses in the sepsis mouse model.

METHODS

Cecal Ligation and Puncture (CLP) model was used to induce sepsis in mice. C57BL/6 mice were divided into sham, CLP-induced sepsis mice, CLP-induced sepsis mice receiving 25 mg/kg, and 125 mg/kg imipenem. Blood and liver samples were obtained and bacterial load, endotoxin level, and liver enzymes were evaluated. The concentration and mRNA expression of cytokines were also determined.

RESULTS

Sepsis mice treated with a high dose (125 mg/kg) of imipenem showed a significant reduction in bacterial load, while increased liver enzymes, endotoxin level, and inflammatory cytokine production in plasma and liver. In contrast, significant reduction in the liver enzymes, bacterial load, endotoxin levels, and inflammatory cytokine levels was observed in the mice treated with a low dose (25 mg/kg) of imipenem compared with other mice groups. Liver tissue pathology of mice indicated little tissue destruction in the sepsis mice treated with 25 mg/kg of imipenem compared to other groups. Mice receiving 25 mg/kg of imipenem had better survival rate.

CONCLUSIONS

Our results demonstrated the dose-dependent effect of subcutaneous administration of imipenem on the inflammatory responses in sepsis mice. A dose of 25 mg/kg imipenem resulted in better pathology, lower inflammatory mediators, and increased survival rate in sepsis mice.

Association of inflammatory biomarkers with subsequent clinical course in suspected late onset sepsis in preterm neonates

BACKGROUND

Sepsis is a major health issue in preterm infants. Biomarkers are used to diagnose and monitor patients with sepsis, but C-reactive protein (CRP) is proven not predictive at onset of late onset neonatal sepsis (LONS) diagnosis. The aim of this study was to evaluate the association of interleukin-6(IL-6), procalcitonin (PCT) and CRP with subsequent sepsis severity and mortality in preterm infants suspected of late onset neonatal sepsis.

METHODS

The study was conducted at the Erasmus University Medical Center-Sophia Children's Hospital Rotterdam. Patient data from January 2018 until October 2019 were reviewed for all preterm neonates born with a gestational age below 32 weeks with signs and symptoms suggestive of systemic infection, in whom blood was taken for blood culture and for inflammatory biomarkers determinations. Plasma IL-6 and PCT were assessed next to CRP at the moment of suspicion. We assessed the association with 7-day mortality and sepsis severity (neonatal sequential organ failure assessment (nSOFA) score, need for inotropic support, invasive ventilation and thrombocytopenia).

RESULTS

A total of 480 suspected late onset neonatal sepsis episodes in 208 preterm neonates (gestational age < 32 weeks) were retrospectively analyzed, of which 143 episodes were classified as sepsis (29.8%), with 56 (11.7%) cases of culture negative, 63 (13.1%) cases of gram-positive and 24(5.0%) cases of gram-negative sepsis. A total of 24 (5.0%) sepsis episodes resulted in death within 7 days after suspicion of LONS. Both IL-6 (adjusted hazard ratio (aHR): 2.28; 95% CI 1.64-3.16; p < 0.001) and PCT (aHR: 2.91; 95% CI 1.70-5.00; p < 0.001) levels were associated with 7-day mortality; however, CRP levels were not significantly correlated with 7-day mortality (aHR: 1.16; 95% CI (0.68-2.00; p = 0.56). Log IL-6, log PCT and log CRP levels were all significantly correlated with the need for inotropic support.

CONCLUSIONS

Our findings show that serum IL-6 and PCT levels at moment of suspected late onset neonatal sepsis offer valuable information about sepsis severity and mortality risk in infants born below 32 weeks of gestation. The discriminative value was superior to that of CRP. Determining these biomarkers in suspected sepsis may help identify patients with imminent severe sepsis, who may require more intensive monitoring and therapy.

Exhaled Volatile Organic Compounds during Inflammation Induced by TNF-α in Ventilated Rats

Systemic inflammation alters the composition of exhaled breath, possibly helping clinicians diagnose conditions such as sepsis. We therefore evaluated changes in exhaled breath of rats given tumor necrosis factor-alpha (TNF-α). Thirty male Sprague-Dawley rats were randomly assigned to three groups (n = 10 each) with intravenous injections of normal saline (control), 200 µg·kg⁻¹ bodyweight TNF-α (TNF-α-200), or 600 µg·kg⁻¹ bodyweight TNF-α (TNF-α-600), and were observed for 24 h or until death. Animals were ventilated with highly-purified synthetic air to analyze exhaled air by multicapillary column–ion mobility spectrometry. Volatile organic compounds (VOCs) were identified from a database. We recorded blood pressure and cardiac output, along with cytokine plasma concentrations. Control rats survived the 24 h observation period, whereas mean survival time decreased to 22 h for TNF-α-200 and 23 h for TNF-α-600 rats. Mean arterial pressure decreased in TNF-α groups, whereas IL-6 increased, consistent with mild to moderate inflammation. Hundreds of VOCs were detected in exhalome. P-cymol increased by a factor-of-two 4 h after injection of TNF-α-600 compared to the control and TNF-α-200. We found that 1-butanol and 1-pentanol increased in both TNF-α groups after 20 h compared to the control. As breath analysis distinguishes between two doses of TNF-α and none, we conclude that it might help clinicians identify systemic inflammation.

Staging and Personalized Intervention for Infection and Sepsis

Background: Sepsis is defined as a dysregulated host response to infection, resulting in life-threatening organ dysfunction. It is now understood that this dysregulation not only constitutes excessive inflammation, but also sustained immune suppression. Immune-modulatory therapies thus have great potential for novel sepsis therapies. Here, we provide a review of biomarkers and functional assays designed to immunologically stage patients with sepsis as well as therapies designed to alter the innate and adaptive immune systems of patients with sepsis beneficially. Methods: A search of PubMed/MEDLINE and clinicaltrials.gov was performed between October 1, 2019 and December 22, 2019 using search terms such as "sepsis immunotherapy," "sepsis biomarkers," "sepsis clinical trials," and variations thereof. Results: Despite more than 30 years of research, there is still no Food and Drug Administration (FDA)-cleared biomarker that has proven to be effective in either identifying patients with sepsis who are at an increased risk of adverse outcomes or responsive to specific interventions. Similarly, past clinical trials investigating new treatment strategies have rarely stratified patients with sepsis. Overall, the results of these trials have been disappointing. Novel efforts to properly gauge an individual patient's immune response and choose an appropriate immunomodulatory agent based on the results are underway. Conclusion: Our evolving understanding of the different mechanisms perturbing immune homeostasis during sepsis strongly suggests that future successes will depend on finding the right therapy for the right patient and administering it at the right time. For such a personalized medicine approach, novel biomarkers and functional assays to properly stage the patient with sepsis will be crucial. The growing repertoire of immunomodulatory agents at our disposal, as well as re-appraisal of agents that have already been tested in unstratified cohorts of patients with sepsis, may finally translate into successful treatment strategies for sepsis.

Diagnostic and prognostic value of interleukin-6, pentraxin 3, and procalcitonin levels among sepsis and septic shock patients: a prospective controlled study according to the Sepsis-3 definitions

Background

This study investigated the clinical value of interleukin-6 (IL-6), pentraxin 3 (PTX3), and procalcitonin (PCT) in patients with sepsis and septic shock diagnosed according to the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3).

Methods

Serum levels of IL-6, PTX3, and PCT were measured in 142 enrolled subjects (51 with sepsis, 46 with septic shock, and 45 as controls). Follow-up IL-6 and PTX3 levels were measured in patients with initial septic shock within 24 h of hospital discharge. Optimal cut-off values were determined for sepsis and septic shock, and prognostic values were evaluated.

Results

Serum IL-6 levels could discriminate sepsis (area under the curve [AUC], 0.83–0.94, P <  0.001; cut-off value, 52.60 pg/mL, 80.4% sensitivity, 88.9% specificity) from controls and could distinguish septic shock (AUC, 0.71–0.89; cut-off value, 348.92 pg/mL, 76.1% sensitivity, 78.4% specificity) from sepsis. Twenty-eight-day mortality was significantly higher in the group with high IL-6 (≥ 348.92 pg/mL) than in the group with low IL-6 (< 348.92 pg/mL) (P = 0.008). IL-6 was an independent risk factor for 28-day mortality among overall patients (hazard ratio, 1.0004; 95% confidence interval, 1.0003–1.0005; p = 0.024). In septic shock patients, both the initial and follow-up PTX3 levels were consistently significantly higher in patients who died than in those who recovered (initial p = 0.004; follow-up P <  0.001).

Conclusions

The diagnostic and prognostic value of IL-6 was superior to those of PTX3 and PCT for sepsis and septic shock.

Development of an IL-6 point-of-care assay: utility for real-time monitoring and management of cytokine release syndrome and sepsis

Aim: Bedside or point-of-care testing (POCT) provides immediate results, allowing for rapid clinical decision making and management of critically ill patients. IL-6 is a central mediator in cytokine release syndrome and sepsis, two potentially life-threatening events. A real-time point-of-care measurement of IL-6 readily available in hospitals and/or to clinicians could provide a valuable tool for decision making. Materials & methods: An IL-6 assay is developed on a POCT device (Proxim, CA, USA), with comparison data measured by ELISA, Ella, and the Roche Cobas. Results: Samples evaluated on a Proxim POCT device showed good correlation with data from multiple platforms. Conclusions: An IL-6 point-of-care assay was developed as potential tool for rapid clinical decision making and management of patients with sepsis and/or cytokine release syndrome.

Plasma interleukin-6 concentration for the diagnosis of sepsis in critically ill adults

BACKGROUND

The definition of sepsis has evolved over time, along with the clinical and scientific knowledge behind it. For years, sepsis was defined as a systemic inflammatory response syndrome (SIRS) in the presence of a documented or suspected infection. At present, sepsis is defined as a life-threatening organ dysfunction resulting from a dysregulated host response to infection. Even though sepsis is one of the leading causes of mortality in critically ill patients, and the World Health Organization (WHO) recognizes it as a healthcare priority, it still lacks an accurate diagnostic test. Determining the accuracy of interleukin-6 (IL-6) concentrations in plasma, which is proposed as a new biomarker for the diagnosis of sepsis, might be helpful to provide adequate and timely management of critically ill patients, and thus reduce the morbidity and mortality associated with this condition.

OBJECTIVES

To determine the diagnostic accuracy of plasma interleukin-6 (IL-6) concentration for the diagnosis of bacterial sepsis in critically ill adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, and Web of Science on 25 January 2019. We screened references in the included studies to identify additional studies. We did not apply any language restriction to the electronic searches.

SELECTION CRITERIA

We included diagnostic accuracy studies enrolling critically ill adults aged 18 years or older under suspicion of sepsis during their hospitalization, where IL-6 concentrations were evaluated by serological measurement.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and extracted data. We assessed the methodological quality of studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. We estimated a summary receiver operating characteristic (SROC) curve by fitting a hierarchical summary ROC (HSROC) non-linear mixed model. We explored sources of heterogeneity using the HSROC model parameters. We conducted all analyses in the SAS statistical software package and R software.

MAIN RESULTS

We included 23 studies (n = 4192) assessing the accuracy of IL-6 for the diagnosis of sepsis in critically ill adults. Twenty studies that were available as conference proceedings only are awaiting classification. The included participants were heterogeneous in terms of their distribution of age, gender, main diagnosis, setting, country, positivity threshold, sepsis criteria, year of publication, and origin of infection, among other factors. Prevalence of sepsis greatly varied across studies, ranging from 12% to 78%. We considered all studies to be at high risk of bias due to issues related to the index test domain in QUADAS-2. The SROC curve showed a great dispersion in individual studies accuracy estimates (21 studies, 3650 adult patients), therefore the considerable heterogeneity in the collected data prevented us from calculating formal accuracy estimates. Using a fixed prevalence of sepsis of 50% and a fixed specificity of 74%, we found a sensitivity of 66% (95% confidence interval 60 to 72). If we test a cohort 1000 adult patients under suspicion of sepsis with IL-6, we will find that 330 patients would receive appropriate and timely antibiotic therapy, while 130 patients would be wrongly considered to have sepsis. In addition, 370 out of 1000 patients would avoid unnecessary antibiotic therapy, and 170 patients would have been undiagnosed of sepsis. This numerical approach should be interpreted with caution due to the limitations described above.

AUTHORS' CONCLUSIONS

Our evidence assessment of plasma interleukin-6 concentrations for the diagnosis of sepsis in critically ill adults reveals several limitations. High heterogeneity of collected evidence regarding the main diagnosis, setting, country, positivity threshold, sepsis criteria, year of publication, and the origin of infection, among other factors, along with the potential number of misclassifications, remain significant constraints for its implementation. The 20 conference proceedings assessed as studies awaiting classification may alter the conclusions of the review once they are fully published and evaluated. Further studies about the accuracy of interleukin-6 for the diagnosis of sepsis in adults that apply rigorous methodology for conducting diagnostic test accuracy studies are needed. The conclusions of the review will likely change once the 20 studies pending publication are fully published and included.

Immune therapy in sepsis: Are we ready to try again?

Immune therapy to ease the burden of sepsis has thus far failed to consistently improve patient outcomes. Advances in cancer immune therapy and awareness that prolonged immune-suppression in sepsis can leave patients vulnerable to secondary infection and death have driven resurgence in the field of sepsis immune-therapy investigation. As we develop and evaluate these novel therapies, we must learn from past experiences where single-mediator targeted immune therapies were blindly delivered to heterogeneous patient cohorts with complex and evolving immune responses. Advances in genomics, proteomics, metabolomics, and point-of-care technology, coupled with a better understanding of sepsis pathogenesis, have meant that personalised immune-therapy is on the horizon. Here, we review the complex immune pathogenesis in sepsis and the contemporary immune therapies that are being investigated to manipulate this response. An outline of the immune biomarkers that may be used to support this approach is also provided.

Precision Immunotherapy for Sepsis

Decades of sepsis research into a specific immune system-targeting adjunctive therapy have not resulted in the discovery of an effective compound. Apart from antibiotics, source control, resuscitation and organ support, not a single adjunctive treatment is used in current clinical practice. The inability to determine the prevailing immunological phenotype of patients and the related large heterogeneity of study populations are regarded by many as the most important factors behind the disappointing results of past clinical trials. While the therapeutic focus has long been on immunosuppressive strategies, increased appreciation of the importance of sepsis-induced immunoparalysis in causing morbidity and mortality in sepsis patients has resulted in a paradigm shift in the sepsis research field towards strategies aimed at enhancing the immune response. However, similar to immunosuppressive therapies, precision medicine is imperative for future trials with immunostimulatory compounds to succeed. As such, identifying those patients with a severely suppressed or hyperactive immune system who will most likely benefit from either immunostimulatory or immunosuppressive therapy, and accurate monitoring of both the immune and treatment response is crucial. This review provides an overview of the challenges lying ahead on the path towards precision immunotherapy for patients suffering from sepsis.

Can intravenous steroid administration reduce postoperative pain scores following total knee arthroplasty?: A meta-analysis

BACKGROUND

The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to evaluate whether intravenous steroids would result in reduced acute pain and postoperative nausea and vomiting (PONV) among patients undergoing total knee arthroplasty (TKA).

METHODS

Electronic databases, including PubMed, Embase, Web of Science, and the Cochrane Library, were searched to identify articles published from database inception to July 2016. RCTs that compared the effects of intravenous steroids with the effects of placebo among patients undergoing TKA were included in this meta-analysis. The primary outcomes were visual analogue scale (VAS) scores after 12, 24, and 48 hours of rest and PONV incidence. The secondary outcomes were blood glucose levels and incidence of infection. We calculated the risk ratio (RR) with its corresponding 95% confidence interval (CI) for dichotomous outcomes and the mean difference (MD) with its corresponding 95% CI for continuous outcomes.

RESULTS

Seven clinical trials involving 434 patients were included in the final meta-analysis. The pooled results indicated that intravenous steroids were associated with decreased VAS scores after 24 hours (MD = -10.21, 95%CI = -18.80 to -1.63, P = .020) and 48 hours (MD = -2.60, 95%CI = -4.70 to -0.50, P = .015) of rest. Moreover, intravenous steroids were also associated with decreased risk of nausea (RR = 0.58, 95% CI 0.44-0.77, P = .000) and vomiting (RR = 0.46, 95% CI = 0.24-0.88, P = .019). However, intravenous steroids were also associated with increased blood glucose levels. No significant difference in the risk of infection was identified between the 2 groups.

CONCLUSION

Intravenous steroids may be associated with decreased pain intensity and decreased risk of nausea and vomiting during the early period following TKA. However, evidence supporting its use is limited by the low quality of and variations in dosing regimens between the included RCTs. Thus, more high-quality RCTs are needed to identify the optimal drug administration intervals for maximal pain control.

Variation in the levels of IL-6 in pediatric patients with severe bacterial infectious diseases and correlation analysis between the levels of IL-6 and procalcitonin

The objective of the present study was to investigate variations in the levels of interleukin (IL)-6, procalcitonin (PCT), and C-reactive protein (CRP) in children with severe bacterial infectious diseases and to analyze the correlation between the levels of IL-6 and PCT to determine the value of combined diagnosis with IL-6 and PCT. We analyzed 126 patients admitted to Xuzhou Children's Hospital for treatment, who were divided into severe bacterial infection (observation group, n=65) and non-bacterial infection groups (control group, n=61). The levels of IL-6, PCT, and CRP were measured and compared between the two groups. Data from both groups were statistically analyzed. The levels of IL-6, PCT, and CRT in the observation group were significantly higher than those in the control group (P<0.01); in the observation group, the levels of IL-6 and PCT on the 5th and 10th day after treatment were significantly lower than those before treatment (P<0.01); PCT showed better value for diagnosing severe bacterial infections compared with IL-6 and CRP; there was a positive correlation between the levels of IL-6 and PCT in the observation group; and the sensitivity and specificity of combined diagnosis with IL-6 and PCT for severe bacterial infection was 93.84% and 96.72%, respectively, which were significantly higher than those for diagnosis with only IL-6 (P<0.01). In conclusion, IL-6 combined with PCT can serve as an indicator with high sensitivity for detection of severe bacterial infections in children, which is of great significance for the differential diagnosis of severe bacterial infections in the early stage.

Human Brain Chemokine and Cytokine Expression in Sepsis: A Report of Three Cases

BACKGROUND

Sepsis is a systemic response to infection that can affect brain function by inducing resident cells (including astrocytes and microglia) to generate brain chemokines and cytokines. However, there are few studies on the human brain. Since this information may shed further light on pathogenesis, our study objective was to measure the expression of 36 chemokines and cytokines in autopsied brain from 3 cases of sepsis and 10 controls, and to relate this to astrocyte and microglial activation.

METHODS

The right frontal pole was removed at autopsy and chemokine and cytokine expression measured by multiplexed enzyme-linked immunosorbent assay and real-time quantitative polymerase chain reaction (qPCR). Immunohistochemistry and image analysis were carried out to determine the expression of glial fibrillary acidic protein (GFAP), a marker of activated astrocytes, and CD68 and CD45, markers of activated microglial cells.

RESULTS

Concentrations of the chemokines CXCL8, CXCL10, CXCL12, CCL13 and CCL22 were increased in pooled data from the three cases of sepsis (p<0.05); however, their messenger RNA (mRNA) expression was unaltered. CXCL13, CXCL1, CXCL2, CCL1, CCL2, CCL8, CCL20, (interleukin) IL-16, IL-1β and (tumour necrosis factor) TNF concentrations showed increases in two of three sepsis cases. Additionally, individual sepsis cases showed increases in mRNA expression for HDAC (histone deacetylase) 6 and EIF (eukaryotic translation initiation factor) 4A2. Brain GFAP expression was significantly increased (p<0.05) in pooled data from the three sepsis cases. Individual sepsis cases showed increases in CD68 or CD45 expression.

CONCLUSIONS

These expression patterns add to our understanding of the pathogenesis of sepsis and its effects on the brain.

Association between Interleukin-6 Promoter Polymorphism (-174 G/C), Serum Interleukin-6 Levels and Mortality in Severe Septic Patients

The association between interleukin (IL)-6 promoter polymorphism (-174 G/C), circulating IL-6 levels and mortality in septic patients has scarcely been addressed, and then only in studies of small sample size, and a direct association among them has not been previously reported. Therefore, the purpose of our study was to determine whether this association exists. An observational, prospective and multicenter study including severe septic patients was undertaken and serum IL-6 levels at severe sepsis diagnosis and IL-6 promoter polymorphism (-174 G/C) were determined. The end-point of the study was 30-day mortality. The study included 263 patients with the following genotypes of IL-6 promoter polymorphism (-174 G/C): 123 (46.8%) GG, 110 (41.8%) GC and 30 (11.4%) CC. CC homozygous patients showed lower sepsis-related organ failure assessment (SOFA) score, serum IL-6 levels and mortality at 30 days compared to those with other genotypes (GC or GG). On regression analysis, CC homozygous patients showed lower 30-day mortality than those with genotype GG (odds ratio = 0.21; 95% CI = 0.053−0.838; p = 0.03) or GC (hazard ratio = 0.28; 95% CI = 0.074−1.037; p = 0.06). The most important results of our study were that CC might be a favorable genotype in septic patients showing lower serum IL-6 levels and lower risk of death within 30 days.

Immunotherapeutic implications of IL-6 blockade for cytokine storm

IL-6 contributes to host defense against infections and tissue injuries. However, exaggerated, excessive synthesis of IL-6 while fighting environmental stress leads to an acute severe systemic inflammatory response known as ‘cytokine storm’, since high levels of IL-6 can activate the coagulation pathway and vascular endothelial cells but inhibit myocardial function. Remarkable beneficial effects of IL-6 blockade therapy using a humanized anti-IL-6 receptor antibody, tocilizumab were recently observed in patients with cytokine release syndrome complicated by T-cell engaged therapy. In this review we propose the possibility that IL-6 blockade may constitute a novel therapeutic strategy for other types of cytokine storm, such as the systemic inflammatory response syndrome including sepsis, macrophage activation syndrome and hemophagocytic lymphohistiocytosis.

Cytokine patterns in cancer patients: A review of the correlation between interleukin 6 and prognosis

OBJECTIVE

In tumor patients, IL-6 appears to be one component of a consistent cancer-associated cytokine network resulting in both a systemic immune stimulation and a microenvironment of cancer-induced immune suppression that ultimately protects the cancer cells. IL-6 has been associated with prognosis in cancer patients, but so far a systemical analysis has not been carried out.

METHODS

The present meta-analysis studies the relation between IL-6 serum levels and the prognosis of cancer patients in the available clinical literature of 100 articles published between 1993 and 2013 comprising 11,583 patients.

RESULTS

The IL-6 serum level was described as significantly correlating with survival in 82/101 series comprising 85.6% of patients (9917/11,583) with 23 different cancer types. A total of 64 studies dichotomized patient cohorts according to various cut-off IL-6 serum levels: in 59/64 of these series corresponding to 94.5% of the reported patients (7694/8142) significant correlations between IL-6 serum level and survival were seen. The median survival of cancer patients had been determined above various cut-off levels of serum IL-6 in 24 dichotomized studies (26 cohorts). There was a highly significant inverse correlation between median survival of the cohorts with IL-6 serum level above cut-off (1272 patients) and their corresponding IL-6 cut-off values (Spearman R -0,48 p= < 0.001) following a linear regression when both parameters were log-transformed (p < 0.001). A significant correlation between increasing serum IL-6 and tumor stage or metastases was described in 39/44 studies and 91% of published patients (4221/4636) where clinical parameters had been specified.

CONCLUSIONS

Closely associated with the patient's clinical condition and independent of the cancer histology, the increased IL-6 serum level uniformly appears to correlate with survival as paraneoplastic condition in later cancer stages independent of the cancer type. Modifications of this paraneoplastic immune reaction may offer new therapeutic options in cancer.

Inflammatory molecules expression pattern for identifying pathogen species in febrile patient serum

Inflammatory molecules, such as cytokines and chemokines, have been considered markers for bacterial or viral infection in serum of patients in numerous studies. The aim of the present study was to investigate whether we were able to identify the pathogen species through patterns of inflammatory molecules. A total of 132 patients with elevated body temperature (tympanic temperature, >38.3°C) were recruited for this study. The concentrations of various inflammatory molecules in the patients' serum were evaluated using a cytometric bead array. Higher concentrations of interleukin (IL)-6 and IL-8 were detected in bacterial infection groups (patients with positive and negative blood cultures), as compared with the viral infection group. Viral infection (including influenza and dengue viral infections) was associated with higher concentrations of interferon-γ-inducible protein 10 (IP-10), as compared with the bacterial infection group. In addition, IL-8 levels in the gram-negative bacteria group were higher, as compared with the gram-positive bacteria group. However, IL-8 was insufficient for bacterial species identification. By contrast, dengue virus infection induced the highest serum level of IP-10 among all groups. In conclusion, detection of the patterns of inflammatory molecules may aid the subsequent management and treatment modalities in hospitals, although evaluation of these molecules alone may be insufficient for identifying the pathogen species.

Cytokines as Early Markers of Colorectal Anastomotic Leakage: A Systematic Review and Meta-Analysis

Purpose. Colorectal anastomotic leakage (CAL) is one of the most severe complications after colorectal surgery. This meta-analysis evaluates whether systemic or peritoneal inflammatory cytokines may contribute to early detection of CAL. Methods. Systematic literature search was performed in the acknowledged medical databases according to the PRISMA guidelines to identify studies evaluating systemic and peritoneal levels of TNF, IL-1β, IL-6, and IL-10 for early detection of CAL. Means and standard deviations of systemic and peritoneal cytokine levels were extracted, respectively, for patients with and without CAL. The meta-analysis of the mean differences was carried out for each postoperative day using Review Manager. Results. Seven articles were included. The meta-analysis was performed with 5 articles evaluating peritoneal cytokine levels. Peritoneal levels of IL-6 were significantly higher in patients with CAL compared to patients without CAL on postoperative days 1, 2, and 3 (P < 0.05). Similar results were found for peritoneal levels of TNF but on postoperative days 3, 4, and 5 (P < 0.05). The articles regarding systemic cytokine levels did not report any significant difference accordingly. Conclusion. Increased postoperative levels of peritoneal IL-6 and TNF are significantly associated with CAL and may contribute to its early detection.

Biomarkers of necrotising soft tissue infections: aspects of the innate immune response and effects of hyperbaric oxygenation-the protocol of the prospective cohort BIONEC study

INTRODUCTION

The mortality and amputation rates are still high in patients with necrotising soft tissue infections (NSTIs). It would be ideal to have a set of biomarkers that enables the clinician to identify high-risk patients with NSTI on admission. The objectives of this study are to evaluate inflammatory and vasoactive biomarkers as prognostic markers of severity and mortality in patients with NSTI and to investigate whether hyperbaric oxygen treatment (HBOT) is able to modulate these biomarkers. The overall hypothesis is that plasma biomarkers can be used as prognostic markers of severity and mortality in patients with NSTI and that HBOT reduces the inflammatory response.

METHODS AND ANALYSIS

This is a prospective, observational study being conducted in a tertiary referral centre. Biomarkers will be measured in 114 patients who have been operatively diagnosed with NSTI. On admission, baseline blood values will be obtained. Following surgery and HBOT, daily blood samples for measuring regular inflammatory and vasoactive biomarkers (pentraxin-3, interleukin-6 and nitrite) will be acquired. Samples will be analysed using validated ELISA assays, chemiluminescence and Griess reaction. Clinical data will be obtained during admission in the intensive care unit for a maximum of 7 days. The primary analysis will focus on pentraxin-3, interleukin-6 and nitrite as early markers of disease severity in patients with NSTI.

ETHICS AND DISSEMINATION

The study has been approved by the Regional Scientific Ethical Committee of Copenhagen (H-2-2014-071) and the Danish Data Protection Agency (J. no. 30-0900 and J. no. 30-1282). Results will be presented at national and international conferences and published in peer-reviewed scientific journals.

TRIAL REGISTRATION

NCT02180906.

Red blood cell distribution width during the first week is associated with severity and mortality in septic patients

Objective

Higher values of red blood cell distribution width (RDW) have been found in non-surviving than in surviving septic patients. However, it is unknown whether RDW during the first week of sepsis evolution is associated with sepsis severity and early mortality, oxidative stress and inflammation states, and these were the aims of the study.

Methods

We performed a prospective, observational, multicenter study in six Spanish Intensive Care Units with 297 severe septic patients. We measured RDW, serum levels of malondialdehyde (MDA) to assess oxidative stress, and tumour necrosis factor (TNF)-α to assess inflammation at days 1, 4, and 8. The end-point was 30-day mortality.

Results

We found higher RDW in non-surviving (n = 104) than in surviving (n = 193) septic patients at day 1 (p = 0.001), day 4 (p = 0.001), and day 8 (p = 0.002) of ICU admission. Cox regression analyses showed that RDW at day 1 (p<0.001), 4 (p = 0.005) and 8 (p = 0.03) were associated with 30-day mortality. Receiver operating characteristic curves showed that RDW at day 1 (p<0.001), 4 (p<0.001), and 8 (p<0.001) could be used to predict 30-day mortality. RDW showed a positive correlation with serum MDA levels at day 1 and day 4, with serum TNF-α levels at days 4 and 8, and with SOFA score at days 1, 4 and 8.

Conclusions

The major findings of our study were that non-surviving septic patients showed persistently higher RDW during the first week of ICU stay than survivors, that RDW during the first week was associated with sepsis severity and mortality, that RDW during the first week could be used as biomarker of outcome in septic patients, and that there was an association between RDW, serum MDA levels, and serum TNF-α levels during the first week.

A peptide of heparin cofactor II inhibits endotoxin-mediated shock and invasive Pseudomonas aeruginosa infection

Sepsis and septic shock remain important medical problems with high mortality rates. Today's treatment is based mainly on using antibiotics to target the bacteria, without addressing the systemic inflammatory response, which is a major contributor to mortality in sepsis. Therefore, novel treatment options are urgently needed to counteract these complex sepsis pathologies. Heparin cofactor II (HCII) has recently been shown to be protective against Gram-negative infections. The antimicrobial effects were mapped to helices A and D of the molecule. Here we show that KYE28, a 28 amino acid long peptide representing helix D of HCII, is antimicrobial against the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, the Gram-positive Bacillus subtilis and Staphylococcus aureus, as well as the fungus Candida albicans. Moreover, KYE28 binds to LPS and thereby reduces LPS-induced pro-inflammatory responses by decreasing NF-κB/AP-1 activation in vitro. In mouse models of LPS-induced shock, KYE28 significantly enhanced survival by dampening the pro-inflammatory cytokine response. Finally, in an invasive Pseudomonas infection model, the peptide inhibited bacterial growth and reduced the pro-inflammatory response, which lead to a significant reduction of mortality. In summary, the peptide KYE28, by simultaneously targeting bacteria and LPS-induced pro-inflammatory responses represents a novel therapeutic candidate for invasive infections.

Anesthetic management for patients with perforation peritonitis

Perforation peritonitis is a common surgical emergency. Anesthesia in patients with perforation peritonitis can be challenging. Delayed presentations, old age, hemodynamic instability, presence of sepsis and organ dysfunction are some of the predictors of poor outcome in such patients. Pre-operative optimization can reduce intraoperative and post-operative morbidity and mortality, but surgery should not be unnecessarily delayed. Intensive care in critical care settings may be essential.

Current concept of abdominal sepsis: WSES position paper

Although sepsis is a systemic process, the pathophysiological cascade of events may vary from region to region.

Abdominal sepsis represents the host’s systemic inflammatory response to bacterial peritonitis.

It is associated with significant morbidity and mortality rates, and is the second most common cause of sepsis-related mortality in the intensive care unit.

The review focuses on sepsis in the specific setting of severe peritonitis.

A key regulatory role for Vav1 in controlling lipopolysaccharide endotoxemia via macrophage-derived IL-6

Macrophages are centrally involved in the pathogenesis of acute inflammatory diseases, peritonitis, endotoxemia, and septic shock. However, the molecular mechanisms controlling such macrophage activation are incompletely understood. In this article, we provide evidence that Vav1, a member of the RhoGEF family, plays a crucial role in macrophage activation and septic endotoxemia. Vav1-deficient mice demonstrated a significantly increased susceptibility for LPS endotoxemia that could be abrogated by anti-IL-6R Ab treatment. Subsequent studies showed that Vav1-deficient macrophages display augmented production of the proinflammatory cytokine IL-6. Nuclear Vav1 was identified as a key negative regulator of macrophage-derived IL-6 production. In fact, Vav1 formed a nuclear DNA-binding complex with heat shock transcription factor 1 at the HSE2 region of the IL-6 promoter to suppress IL-6 gene transcription in macrophages. These findings provide new insights into the pathogenesis of endotoxemia and suggest new avenues for therapy.

Cytokines and signaling molecules predict clinical outcomes in sepsis

Introduction

Inflammatory response during sepsis is incompletely understood due to small sample sizes and variable timing of measurements following the onset of symptoms. The vasopressin in septic shock trial (VASST) compared the addition of vasopressin to norepinephrine alone in patients with septic shock. During this study plasma was collected and 39 cytokines measured in a 363 patients at both baseline (before treatment) and 24 hours. Clinical features relating to both underlying health and the acute organ dysfunction induced by the severe infection were collected during the first 28 days of admission.

Hypothesis

Cluster analysis of cytokines identifies subgroups of patients at differing risk of death and organ failure.

Methods

Circulating cytokines and other signaling molecules were measured using a Luminex multi-bead analyte detection system. Hierarchical clustering was performed on plasma values to create patient subgroups. Enrichment analysis identified clinical outcomes significantly different according to these chemically defined patient subgroups. Logistic regression was performed to assess the importance of cytokines for predicting patient subgroups.

Results

Plasma levels at baseline produced three subgroups of patients, while 24 hour levels produced two subgroups. Using baseline cytokine data, one subgroup of 47 patients showed a high level of enrichment for severe septic shock, coagulopathy, renal failure, and risk of death. Using data at 24 hours, a larger subgroup of 81 patients that largely encompassed the 47 baseline subgroup patients had a similar enrichment profile. Measurement of two cytokines, IL2 and CSF2 and their product were sufficient to classify patients into these subgroups that defined clinical risks.

Conclusions

A distinct pattern of cytokine levels measured early in the course of sepsis predicts disease outcome. Subpopulations of patients have differing clinical outcomes that can be predicted accurately from small numbers of cytokines. Design of clinical trials and interventions may benefit from consideration of cytokine levels.

Traditional chinese medicine diagnosis "yang-xu zheng": significant prognostic predictor for patients with severe sepsis and septic shock

Pathogenesis of sepsis includes complex interaction between pathogen activities and host response, manifesting highly variable signs and symptoms, possibly delaying diagnosis and timely life-saving interventions. This study applies traditional Chinese medicine (TCM) Zheng diagnosis in patients with severe sepsis and septic shock to evaluate its adaptability and use as an early predictor of sepsis mortality. Three-year prospective observational study enrolled 126 septic patients. TCM Zheng diagnosis, Acute Physiology and Chronic Health Evaluation (APACHE) II score, and blood samples for host response cytokines measurement (tumor necrosis factor-α, Interleukin-6, Interleukin-8, Interleukin-10, Interleukin-18) were collected within 24 hours after admission to Intensive Care Unit. Main outcome was 28-day mortality; multivariate logistic regression analysis served to determine predictive variables of the sepsis mortality. APACHE II score, frequency of Nutrient-phase heat, and Qi-Xu and Yang-Xu Zhengs were significantly higher in nonsurvivors. The multivariate logistic regression analysis identified Yang-Xu Zheng as the outcome predictor. APACHE II score and levels of five host response cytokines between patients with and without Yang-Xu Zheng revealed significant differences. Furthermore, cool extremities and weak pulse, both diagnostic signs of Yang-Xu Zheng, were also proven independent predictors of sepsis mortality. TCM diagnosis “Yang-Xu Zheng” may provide a new mortality predictor for septic patients.

Immune response after systematic lymph node dissection in lung cancer surgery: changes of interleukin-6 level in serum, pleural lavage fluid, and lung supernatant in a dog model

BACKGROUND

Systematic nodal dissection (SND) is regarded as a core component of lung cancer surgery. However, there has been a concern on the increased morbidity associated with SND. This study was performed to investigate whether or not SND induces significant immune response.

METHODS

Sixteen dogs were divided into two groups; group 1 (n = 8) underwent thoracotomy only, and group 2 (n = 8) underwent SND after thoracotomy. We compared interleukin-6 (IL-6) levels in serum, pleural lavage fluid and lung supernatant at the time of thoracotomy (T0) and at 2 h(T1) after thoracotomy (group 1) or SND (group 2). Severity of inflammation and IL-6 expression in lung tissue were evaluated in a semi-quantitative manner.

RESULTS

The operative results were comparable. IL-6 was not detected in serum in either group. IL-6 in pleural lavage fluid marginally increased from 4.75 ± 3.74 pg/mL at T0 to 19.75 ± 8.67 pg/mL at T1 in group 1 (P = 0.112), and from 7.75 ± 5.35 pg/mL to 17.72 ± 8.58 pg/mL in group 2 (P = 0.068). IL-6 in lung supernatant increased from 0.36 ± 0.14 pg/mL/mg to 1.15 ± 0.17 pg/mL/mg in group 1 (P = 0.003), and from 0.25 ± 0.08 pg/mL/mg to 0.82 ± 0.17 pg/mL/mg in group 2 (P = 0.001). However, the degree of increase in IL-6 in pleural lavage fluid and lung supernatant were not different between two groups (P = 0.421 and P = 0.448). There was no difference in severity of inflammation and IL-6 expression between groups.

CONCLUSIONS

SND did not increase IL-6 in pleural lavage fluid and lung supernatant. This result suggests that SND could be routinely performed in lung cancer surgery without increasing the significant inflammatory response.

Severe septic patients with mitochondrial DNA haplogroup JT show higher survival rates: a prospective, multicenter, observational study

Objective

In a previous cohort study (n=96), we found an association between mitochondrial (mt) DNA haplogroup JT and increased survival of severe septic patients, after controlling for age and serum lactic acid levels. The aim of this research was to increase the predictive accuracy and to control for more confounder variables in a larger cohort (n=196) of severe septic patients, to confirm whether mtDNA haplogroup JT influences short and medium-term survival in these patients.

Methods

We conducted a prospective, multicenter, observational study in six Spanish Intensive Care Units. We determined 30-day and 6-month survival and mtDNA haplogroup in this second cohort of 196 patients and in the global cohort (first and second cohorts combined) with 292 severe septic patients. Multiple logistic regression and Cox regression analyses were used to test for the association of mtDNA haplogroups JT with survival at 30-days and 6-months, controlling for age, sex, serum interleukin-6 levels and SOFA score.

Results

Logistic and Cox regression analyses showed no differences in 30-day and 6-month survival between patients with mtDNA haplogroup JT and other haplogroups in the first cohort (n=96). In the second cohort (n=196), these analyses showed a trend to higher 30-day and 6-month survival in those with haplogroup JT. In the global cohort (n=292), logistic and Cox regression analyses showed higher 30-day and 6-month survival for haplogroup JT. There were no significant differences between J and T sub-haplogroups in 30-day and 6-month survival.

Conclusions

The global cohort study (first and second cohorts combined), the largest to date reporting on mtDNA haplogroups in septic patients, confirmed that haplogroup JT patients showed increased 30-day and 6-month survival. This finding may be due to single nucleotide polymorphism defining the whole haplogroup JT and not separately for J or T sub-haplogroups.

Local and systemic innate immune response to secondary human peritonitis

Introduction

Our aim was to describe inflammatory cytokines response in the peritoneum and plasma of patients with peritonitis. We also tested the hypothesis that scenarios associated with worse outcome would result in different cytokine release patterns. Therefore, we compared cytokine responses according to the occurrence of septic shock, mortality, type of peritonitis and peritoneal microbiology.

Methods

Peritoneal and plasma cytokines (interleukin (IL) 1, tumor necrosis factor α (TNFα), IL-6, IL-10, and interferon γ (IFNγ)) were measured in 66 patients with secondary peritonitis.

Results

The concentration ratio between peritoneal fluid and plasma cytokines varied from 5 (2 to 21) (IFNγ) to 1310 (145 to 3888) (IL-1). There was no correlation between plasma and peritoneal fluid concentration of any cytokine. In the plasma, TNFα, IL-6, IFNγ and IL-10 were higher in patients with shock versus no shock and in nonsurvivors versus survivors (P ≤0.03). There was no differential plasma release for any cytokine between community-acquired and postoperative peritonitis. The presence of anaerobes or Enterococcus species in peritoneal fluid was associated with higher plasma TNFα: 50 (37 to 106) versus 38 (29 to 66) and 45 (36 to 87) versus 39 (27 to 67) pg/ml, respectively (P = 0.02). In the peritoneal compartment, occurrence of shock did not result in any difference in peritoneal cytokines. Peritoneal IL-10 was higher in patients who survived (1505 (450 to 3130) versus 102 (9 to 710) pg/ml; P = 0.04). The presence of anaerobes and Enterococcus species was associated with higher peritoneal IFNγ: 2 (1 to 6) versus 10 (5 to 28) and 7 (2 to 39) versus 2 (1 to 6), P = 0.01 and 0.05, respectively).

Conclusions

Peritonitis triggers an acute systemic and peritoneal innate immune response with a simultaneous release of pro and anti-inflammatory cytokines. Higher levels of all cytokines were observed in the plasma of patients with the most severe conditions (shock, non-survivors), but this difference was not reflected in their peritoneal fluid. There was always a large gradient in cytokine concentration between peritoneal and plasma compartments highlighting the importance of compartmentalization of innate immune response in peritonitis.

Biomarkers of sepsis

Sepsis is an unusual systemic reaction to what is sometimes an otherwise ordinary infection, and it probably represents a pattern of response by the immune system to injury. A hyper-inflammatory response is followed by an immunosuppressive phase during which multiple organ dysfunction is present and the patient is susceptible to nosocomial infection. Biomarkers to diagnose sepsis may allow early intervention which, although primarily supportive, can reduce the risk of death. Although lactate is currently the most commonly used biomarker to identify sepsis, other biomarkers may help to enhance lactate’s effectiveness; these include markers of the hyper-inflammatory phase of sepsis, such as pro-inflammatory cytokines and chemokines; proteins such as C-reactive protein and procalcitonin which are synthesized in response to infection and inflammation; and markers of neutrophil and monocyte activation. Recently, markers of the immunosuppressive phase of sepsis, such as anti-inflammatory cytokines, and alterations of the cell surface markers of monocytes and lymphocytes have been examined. Combinations of pro- and anti-inflammatory biomarkers in a multi-marker panel may help identify patients who are developing severe sepsis before organ dysfunction has advanced too far. Combined with innovative approaches to treatment that target the immunosuppressive phase, these biomarkers may help to reduce the mortality rate associated with severe sepsis which, despite advances in supportive measures, remains high.

Maximal chemiluminescent intensity in response to lipopolysaccharide assessed by endotoxin activity assay on admission day predicts mortality in patients with sepsis

OBJECTIVE

Sepsis is the leading cause of death among critically ill patients. There are, however, few appropriate biomarkers to predict mortality in patients with sepsis. We focused on maximal chemiluminescent intensity in response to lipopolysaccharide assessed by endotoxin activity assay and evaluated the diagnostic value of maximal chemiluminescent intensity on admission day as a predictor of mortality in patients with sepsis.

DESIGN

Prospective, observational study.

SETTING

ICU.

PATIENTS

One hundred and thirty-two patients with sepsis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Within 12 hours after admission, a whole-blood sample was collected, and variables assessed by endotoxin activity assay were measured in each patient. Severity of illness was assessed simultaneously by Acute Physiology and Chronic Health Evaluation (APACHE) II score and Sequential Organ Failure Assessment (SOFA) score. The primary outcome was 28-day mortality. One hundred and fifteen patients survived and 17 died. maximal chemiluminescent intensity values were significantly lower in the nonsurvivors than in the survivors (p <0.05). We investigated maximal chemiluminescent intensity, APACHE II score, and SOFA score as predictors of 28-day mortality. Receiver operating characteristic analysis showed that area under the curve for maximal chemiluminescent intensity was 0.902, which was superior to the area under the curves for APACHE II score (0.836) and SOFA score (0.807). At the optimal cutoff value for maximal chemiluminescent intensity, 21,000 RLU/s, the sensitivity for correct prediction of 28-day mortality was 82.4% and the specificity was 92.2%. Kaplan-Meier analysis showed that low maximal chemiluminescent intensity (<21,000 RLU/s) closely correlated with poor overall patient survival compared with high maximal chemiluminescent intensity (>21,000 RLU/s) (p <0.001 by log-rank test). After adjusting for APACHE II score by Cox regression analysis, maximal chemiluminescent intensity was identified as an independent predictor for the probability of 28-day mortality.

CONCLUSION

Maximal chemiluminescent intensity level measured on admission day appears to have high predictive value for mortality in patients with sepsis.

Is there value in plasma cytokine measurements in patients with severe trauma and sepsis?

For the past thirty years, since IL-1β and TNFα were first cloned, there have been efforts to measure plasma cytokine concentrations in patients with severe sepsis and trauma, and to use these measurements to predict clinical outcome and response to therapies. The numbers of cytokines and chemokines that have been measured in the plasma have literally exploded with the development of multiplex immune approaches. Dozens of relatively small cohort studies have shown plasma cytokine concentrations correlating with outcome in sepsis and trauma. Despite what appears to be a consensus that plasma cytokine concentrations should be useful in the clinical setting, only two cytokines, IL-6 and procalcitonin, have approached routine clinical use. IL-6 has been used as a research tool for entry into sepsis-intervention trials, while procalcitonin is being used clinically at a large number of institutions to distinguish sepsis from other inflammatory processes. For most cytokines, the relative lack of sensitivity and specificity of individual or multiplex cytokine measurements has hindered their utility to predict clinical trajectory in individual patients. The problem rests with a general misunderstanding of cytokine biology, failing to appreciate the general paracrine nature of these mediators, the presence of binding proteins, chaperones and inhibitors in the plasma, and the rapid clearance of these proteins by binding to cell receptors and clearance predominantly by the kidney. The future of using plasma cytokine measurements as an indicator of sepsis/trauma severity or predicting outcome is generally behind us, although there is optimism that procalcitonin measurements may ultimately prove to have utility in the diagnosis of severe sepsis.

A murine model of mild traumatic brain injury exhibiting cognitive and motor deficits

BACKGROUND

Mild traumatic brain injury (TBI) is a serious public health concern affecting more than 1.7 million people in the United States annually. Mild TBI is difficult to diagnose and is clinically associated with impaired motor coordination and cognition.

METHODS

We subjected mice to a mild TBI (mTBI-1 or mTBI-2) induced by a weight drop model. We assessed brain injury histologically and biochemically, the latter by serum neuron-specific enolase and glial fibrillary acidic protein. Systemic and brain inflammation were measured by cytokine array. We determined blood-brain barrier integrity by cerebral vascular leakage of micromolecular and macromolecular fluorescent molecules. We evaluated mice using a rotarod device and novel object recognition to measure motor coordination and cognition, respectively.

RESULTS

Mice undergoing mTBI-1 or mTBI-2 had significant deficits in motor coordination and cognition for several days after injury compared with controls. Furthermore, both mTBI-1 and mTBI-2 caused micromolecular leakage in the blood-brain barrier, whereas only mTBI-2 caused macromolecular leakage. Serum neuron-specific enolase and glial fibrillary acidic protein were elevated acutely and corresponded to the degree of injury, but returned to baseline within 24 h. Serum cytokines interleukin-6 and keratinocyte-derived chemokine were significantly increased within 90 min of TBI. Interleukin-6 levels correlated with the degree of injury.

CONCLUSIONS

The current study provides a reproducible model of mild TBI in mice that exhibits pathologic features of mild TBI in humans. Furthermore, our data suggest that serum cytokines, such as IL-6, may be effective biomarkers for severity of head injury.

Pulse Spectrum Analysis, a Faster and Easier Way to Predict Outcome of Sepsis?

In order to provide a faster and easier way for outcome prediction of sepsis, this study aimed to characterize the pattern of arterial pulse spectrum by a rat cecum ligation and puncture (CLP) model and explore whether specific harmonic components of pulse spectrum are associated with the mortality of CLP rats, followed by the comparison of accuracy between these specific variables and IL-6.

Nineteen Sprague-Dawley rats receiving CLP were analyzed. Femoral artery of each rat was catheterized for blood pressure recording and blood sampling in the first 24 hours after CLP. The former was for off-line pulse spectrum analysis, and the latter for IL-6 assay. These rats were observed for 3-day mortality after CLP, and were divided into survivor or non-survivor groups. Differences of the hemodynamic profile, IL-6, and changes of the harmonics between the 2 groups were analyzed by using the Mann-Whitney test. Kaplan-Meier curves were constructed to characterize cumulative survival with the best prognostic cutoff point.

The characteristic changes of pulse spectrum were different between survivors and non-survivors. The percentage differences of the 2nd harmonic proportion (C2) increased significantly from the 10th hour after CLP, and was higher in the non-survivors. Serum levels of IL-6 were also higher in the non-survivor group. Analyzed by Kaplan-Meier survival curve for 3-day mortality, C2 had a higher accuracy than IL-6 as a predictor.

The pulse spectrum analysis may be applied to evaluate the prognosis of CLP rats, and the rapidly and highly elevated C2 harmonic had a strong association with the 3-day mortality of CLP rats.

Mixed antagonist response and sepsis severity-dependent dysbalance of pro- and anti-inflammatory responses at the onset of postoperative sepsis

It has been postulated that an early systemic inflammatory response syndrome (SIRS) and a subsequent compensatory anti-inflammatory response syndrome (CARS) occur sequentially in sepsis. Co-existence of both is referred to as mixed antagonist response syndrome (MARS). Pro- and anti-inflammatory cytokine production was investigated in patients with postoperative sepsis, a murine peritonitis model and in vitro to further delineate the interaction of hyper- and hypo-inflammation in sepsis. IL-6 and IL-10 were measured in serum samples from 80 patients on d1 and d2 of postoperative sepsis and were similarly determined at various time points after induction of septic peritonitis in mice. Cytokine production of RAW264 macrophages was stimulated in vitro using TLR agonists. IL-6 and IL-10 were measured in supernatants. All cytokine measurements were performed by ELISA. In patients, the initial phase of the immune response to sepsis was characterized by a concomitant elevation of serum IL-6 and IL-10 levels. IL-10 levels were correlated with IL-6 levels in an exponential manner (p<0.001), which could be confirmed in a mouse model of septic peritonitis. In vitro experiments revealed that the observed exponential correlation may occur as function of TLR signaling intensity. Early postoperative sepsis seems to be characterized by a primary MARS. Sepsis severity was positively correlated with a disproportionate elevation of the anti-inflammatory response relative to the pro-inflammatory response, a pattern reminiscent of TLR-driven responses. Detailed characterization of immune responses in sepsis may help to direct standard therapies and to develop effective immunomodulatory strategies.