Designing phase 3 sepsis trials: application of learned experiences from critical care trials in acute heart failure

Reframing sepsis immunobiology for translation: towards informative subtyping and targeted immunomodulatory therapies

Sepsis is a common and deadly condition. Within the current model of sepsis immunobiology, the framing of dysregulated host immune responses into proinflammatory and immunosuppressive responses for the testing of novel treatments has not resulted in successful immunomodulatory therapies. Thus, the recent focus has been to parse observable heterogeneity into subtypes of sepsis to enable personalised immunomodulation. In this Personal View, we highlight that many fundamental immunological concepts such as resistance, disease tolerance, resilience, resolution, and repair are not incorporated into the current sepsis immunobiology model. The focus for addressing heterogeneity in sepsis should be broadened beyond subtyping to encompass the identification of deterministic molecular networks or dominant mechanisms. We explicitly reframe the dysregulated host immune responses in sepsis as altered homoeostasis with pathological disruption of immune-driven resistance, disease tolerance, resilience, and resolution mechanisms. Our proposal highlights opportunities to identify novel treatment targets and could enable successful immunomodulation in the future.

Recent Advances in Immunomodulatory Therapy in Sepsis: A Comprehensive Review

Sepsis remains a critical healthcare challenge, characterized by dysregulated immune responses to infection, leading to organ dysfunction and high mortality rates. Traditional treatment strategies often fail to address the underlying immune dysregulation, necessitating exploring novel therapeutic approaches. Immunomodulatory therapy holds promise in sepsis management by restoring immune balance and mitigating excessive inflammation. This comprehensive review examines the pathophysiology of sepsis, current challenges in treatment, and recent advancements in immunomodulatory agents, including biologics, immunotherapy, and cellular therapies. Clinical trial outcomes, safety profiles, and future research and clinical practice implications are discussed. While immunomodulatory therapies show considerable potential in improving sepsis outcomes, their successful implementation requires further research, collaboration, and integration into standard clinical protocols.

Immunotherapy to treat sepsis induced-immunosuppression: Immune eligibility or outcome criteria, a systematic review

Sepsis-induced immunosuppression (SIS) is the target of multiple clinical studies testing immunotherapies. To date, most trials are performed on a heterogeneous and unselected population. Without any consensual definition of immunosuppression and therapeutic goals, results from these trials remain poorly transposable. In this perspective, we conducted a systematic review aiming at 1/registering the inclusion criteria, 2/ report the outcomes evaluated in this literature. We searched Pubmed, Embase, and ClinicalTrials.gov for studies using an immunotherapy to reverse SIS. This review collected for each study: design, intervention, immune inclusion criteria, outcome, definition of sepsis, and source of infection. From the 80 studies assessed for eligibility, 29 were included: 17 RCT, 6 observational prospective studies, 6 ongoing RCT. Sepsis was defined based upon current recommendations at the time, with most patients presenting at least one organ failure. We found important heterogeneity regarding the use of immune parameters, both as inclusion and as outcome criteria. Only 13 studies selected patients suffering from immunosuppression based on immune biomarkers. Two immune criterias were commonly used: lymphocyte count and monocytic HLA-DR expression. This heterogeneity criteria in studies targeting SIS justify the conduct of a consensus process to define criteria to diagnose SIS and identify relevant outcomes markers.

SC2sepsis: sepsis single-cell whole gene expression database

Sepsis, one of the major challenges in the intensive care unit, is characterized by complex host immune status. Improved understandings of the phenotypic changes of immune cells during sepsis and the driving molecular mechanisms are critical to the elucidation of sepsis pathogenesis. Single-cell RNA sequencing (scRNA-seq), which interprets transcriptome at a single-cell resolution, serves as a useful tool to uncover disease-related gene expression signatures of different cell populations in various diseases. It has also been applied to studies on sepsis immunopathological mechanisms. Due to the fact that most sepsis-related studies utilizing scRNA-seq have very small sample sizes and there is a lack of an scRNA-seq database for sepsis, we developed Sepsis Single-cell Whole Gene Expression Database Website (SC2sepsis) (http://www.rjh-sc2sepsis.com/), integrating scRNA-seq datasets of human peripheral blood mononuclear cells from 45 septic patients and 26 healthy controls, with a total amount of 232 226 cells. SC2sepsis is a comprehensive resource database with two major features: (i) retrieval of 1988 differentially expressed genes between pathological and healthy conditions and (ii) automatic cell-type annotation, which is expected to facilitate researchers to gain more insights into the immune dysregulation of sepsis.

Efficacy and Safety of Vilobelimab (IFX-1), a Novel Monoclonal Anti-C5a Antibody, in Patients With Early Severe Sepsis or Septic Shock-A Randomized, Placebo-Controlled, Double-Blind, Multicenter, Phase IIa Trial (SCIENS Study)

Supplemental Digital Content is available in the text.

Anaphylatoxin C5a, a proinflammatory complement split product, plays a central role in mediating organ dysfunction.

Monitoring circulating dipeptidyl peptidase 3 (DPP3) predicts improvement of organ failure and survival in sepsis: a prospective observational multinational study

Background

Dipeptidyl peptidase 3 (DPP3) is a cytosolic enzyme involved in the degradation of various cardiovascular and endorphin mediators. High levels of circulating DPP3 (cDPP3) indicate a high risk of organ dysfunction and mortality in cardiogenic shock patients.

Methods

The aim was to assess relationships between cDPP3 during the initial intensive care unit (ICU) stay and short-term outcome in the AdrenOSS-1, a prospective observational multinational study in twenty-four ICU centers in five countries. AdrenOSS-1 included 585 patients admitted to the ICU with severe sepsis or septic shock. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by the Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use and need for renal replacement therapy. cDPP3 levels were measured upon admission and 24 h later.

Results

Median [IQR] cDPP3 concentration upon admission was 26.5 [16.2–40.4] ng/mL. Initial SOFA score was 7 [5–10], and 28-day mortality was 22%. We found marked associations between cDPP3 upon ICU admission and 28-day mortality (unadjusted standardized HR 1.8 [CI 1.6–2.1]; adjusted HR 1.5 [CI 1.3–1.8]) and between cDPP3 levels and change in renal and liver SOFA score (p = 0.0077 and 0.0009, respectively). The higher the initial cDPP3 was, the greater the need for organ support and vasopressors upon admission; the longer the need for vasopressor(s), mechanical ventilation or RRT and the higher the need for fluid load (all p < 0.005). In patients with cDPP3 > 40.4 ng/mL upon admission, a decrease in cDPP3 below 40.4 ng/mL after 24 h was associated with an improvement of organ function at 48 h and better 28-day outcome. By contrast, persistently elevated cDPP3 at 24 h was associated with worsening organ function and high 28-day mortality.

Conclusions

Admission levels and rapid changes in cDPP3 predict outcome during sepsis.

Trial Registration ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015.

Transglutaminase 2 as a Marker for Inflammation and Therapeutic Target in Sepsis

Sepsis results in lethal organ malfunction due to dysregulated host response to infection, which is a condition with increasing prevalence worldwide. Transglutaminase 2 (TG2) is a crosslinking enzyme that forms a covalent bond between lysine and glutamine. TG2 plays important roles in diverse cellular processes, including extracellular matrix stabilization, cytoskeletal function, cell motility, adhesion, signal transduction, apoptosis, and cell survival. We have shown that the co-culture of Candida albicans and hepatocytes activates and induces the translocation of TG2 into the nucleus. In addition, the expression and activation of TG2 in liver macrophages was dramatically induced in the lipopolysaccharide-injected and cecal ligation puncture-operated mouse models of sepsis. Based on these findings and recently published research, we have reviewed the current understanding of the relationship between TG2 and sepsis. Following the genetic and pharmacological inhibition of TG2, we also assessed the evidence regarding the use of TG2 as a potential marker and therapeutic target in inflammation and sepsis.

The promise and pitfalls of composite endpoints in sepsis and COVID-19 clinical trials

Composite endpoints reveal the tendency for statistical convention to arise locally within subfields. Composites are familiar in cardiovascular trials, yet almost unknown in sepsis. However, the VITAMINS trial in patients with septic shock adopted a composite of mortality and vasopressor-free days, and an ordinal scale describing patient status rapidly became standard in COVID studies. Aware that recent use could incite interest in such endpoints, we are motivated to flag their potential value and pitfalls for sepsis research and COVID studies.

Levosimendan Efficacy and Safety: 20 years of SIMDAX in Clinical Use

Levosimendan was first approved for clinic use in 2000, when authorisation was granted by Swedish regulatory authorities for the haemodynamic stabilisation of patients with acutely decompensated chronic heart failure. In the ensuing 20 years, this distinctive inodilator, which enhances cardiac contractility through calcium sensitisation and promotes vasodilatation through the opening of adenosine triphosphate-dependent potassium channels on vascular smooth muscle cells, has been approved in more than 60 jurisdictions, including most of the countries of the European Union and Latin America. Areas of clinical application have expanded considerably and now include cardiogenic shock, takotsubo cardiomyopathy, advanced heart failure, right ventricular failure and pulmonary hypertension, cardiac surgery, critical care and emergency medicine. Levosimendan is currently in active clinical evaluation in the US. Levosimendan in IV formulation is being used as a research tool in the exploration of a wide range of cardiac and non-cardiac disease states. A levosimendan oral form is at present under evaluation in the management of amyotrophic lateral sclerosis. To mark the 20 years since the advent of levosimendan in clinical use, 51 experts from 23 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, UK and Ukraine) contributed to this essay, which evaluates one of the relatively few drugs to have been successfully introduced into the acute heart failure arena in recent times and charts a possible development trajectory for the next 20 years.

Levosimendan Efficacy and Safety: 20 Years of SIMDAX in Clinical Use

Levosimendan was first approved for clinical use in 2000, when authorization was granted by Swedish regulatory authorities for the hemodynamic stabilization of patients with acutely decompensated chronic heart failure (HF). In the ensuing 20 years, this distinctive inodilator, which enhances cardiac contractility through calcium sensitization and promotes vasodilatation through the opening of adenosine triphosphate-dependent potassium channels on vascular smooth muscle cells, has been approved in more than 60 jurisdictions, including most of the countries of the European Union and Latin America. Areas of clinical application have expanded considerably and now include cardiogenic shock, takotsubo cardiomyopathy, advanced HF, right ventricular failure, pulmonary hypertension, cardiac surgery, critical care, and emergency medicine. Levosimendan is currently in active clinical evaluation in the United States. Levosimendan in IV formulation is being used as a research tool in the exploration of a wide range of cardiac and noncardiac disease states. A levosimendan oral form is at present under evaluation in the management of amyotrophic lateral sclerosis. To mark the 20 years since the advent of levosimendan in clinical use, 51 experts from 23 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, the United Kingdom, and Ukraine) contributed to this essay, which evaluates one of the relatively few drugs to have been successfully introduced into the acute HF arena in recent times and charts a possible development trajectory for the next 20 years.

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.

Recombinant human milk fat globule-EGF factor VIII (rhMFG-E8) as a therapy for sepsis after acute exposure to alcohol

BACKGROUND

Alcohol intake predisposes to infections and sepsis. Alcohol and sepsis inhibit the expression of milk fat globule epidermal growth factor-factor VIII (MFG-E8), a glycoprotein essential for optimal efferocytosis, resulting in the release of proinflammatory molecules and increased sepsis severity. We previously reported that recombinant mouse (rm) MFG-E8 attenuates sepsis-induced organ injury in rats with acute alcohol intoxication. In order to develop a therapy that can be safely used in humans, we have produced recombinant human (rh) MFG-E8 and evaluated its efficacy to ameliorate sepsis after acute exposure to alcohol.

METHODS

We induced acute alcohol intoxication with a bolus injection of alcohol (1.75 g/kg BW) followed by an intravenous infusion of 300 mg/kg/h alcohol for 10 h. Sepsis was then induced by cecal ligation and puncture (CLP). At -10, 0, and 10 h relative to CLP, rats received MFG-E8 or vehicle (albumin) intravenously. Animals were euthanized at 20 h after CLP for blood and tissue collection. Additional groups of animals were used for a survival study.

RESULTS

Compared to vehicle, rhMFG-E8 treatment ameliorated blood levels of proinflammatory cytokines (% improvement: TNF-α 49.8%, IL-6 34.7%) and endotoxin (61.7%), as well as of transaminases (AST 36.2%, ALT 40.1%) and lactate (18.4%). Rats treated with rhMFG-E8 also had a significant histological attenuation of the acute lung injury, as well as a reduction in the number of apoptotic cells in the thymus (43.4%) and cleaved caspase 3 (38.7%) in the spleen. In addition, rhMFG-E8 improved the 10-day sepsis survival rate from 45 to 80% CONCLUSION: rhMFG-E8 significantly ameliorated sepsis in rats with acute alcohol exposure, demonstrating rhMFG-E8's potential to be developed as an effective therapy for sepsis in alcohol abusers.

High mobility group box protein 1 neutralization therapy in ovine bacteremia: Lessons learned from an ovine septic shock model incorporating intensive care support

Sepsis is a highly complex and often fatal syndrome which varies widely in its clinical manifestations, and therapies that target the underlying uncontrolled immune status in sepsis are needed. The failure of preclinical approaches to provide significant sepsis survival benefit in the clinic is often attributed to inappropriate animal disease models. It has been demonstrated that high mobility group box protein 1 (HMGB1) blockade can reduce inflammation, mortality and morbidity in experimental sepsis without promoting immunosuppression. Within this study, we explored the use of ovine anti-HMGB1 antibodies in a model of ovine septic shock incorporating intensive care supports (OSSICS). Results: Septic sheep exhibited elevated levels of HMGB1 within 12 h after the induction of sepsis. In this study, sepsis was induced in six anaesthetized adult Border Leicester × Merino ewes via intravenous instillation of E. coli and sheep monitored according to intensive care unit standard protocols for 26 h, with the requirement for noradrenaline as the primary endpoint. Septic sheep exhibited a hyperdynamic circulation, renal dysfunction, deranged coagulation profile and severe metabolic acidosis. Sheep were assigned a severity of illness score, which increased over time. While a therapeutic effect of intravenous anti-HMGB1 antibody could not be observed in this model due to limited animal numbers, a reduced bacterial dose induced a septic syndrome of much lower severity. With modifications including a reduced bacterial dose, a longer timeframe and broad spectrum antibiotics, the OSSICS model may become a robust tool for preclinical assessment of sepsis therapeutics.

Association between fluid overload and SOFA score kinetics in septic shock patients: a retrospective multicenter study

Background

Fluid infusion represents one of the cornerstones of resuscitation therapies in order to increase oxygen delivery during septic shock. Fluid overload as a consequence of excessive fluid administration seems to be linked to worse long-term outcome. However, its immediate effect on patient’s clinical state is poorly described. The goal of this study was to assess the impact of FO on SOFA score kinetics as a surrogate marker of organ dysfunction from day 0 to day 5.

Material and methods

Retrospective, multicenter, investigator-initiated study. All adult patients (> 18 years old) admitted from January 2012 to April 2017 in one of the three ICUs for septic shock, secondary to peritonitis or pulmonary infection and mechanically ventilated, were included. Univariate analysis was performed with Student’s t and chi-square test, for continuous and categorical variables, respectively. A multivariate linear regression model evaluated the impact of FO on delta SOFA score from day 0 to day 5. Secondly, a multivariate mixed-model accounting for repeated measures analyzed the impact of FO on SOFA score kinetics.

Results

One hundred twenty-nine patients met the inclusion criteria and were assigned into FO and no FO groups. FO occurred in 39% of the patients. The difference between SOFA score at day 0 and day 5 was more than twofold higher in the no FO group than in the FO group with a difference of 2.37 between the two groups (4.52 vs. 2.15; p = 0.001). Cumulative fluid intake at day 5 was higher in the FO group (2738 vs. 8715 ml, p < 0.001). In multivariate analysis, FO was associated with delta SOFA score: aRR = 0.15 (95% CI 0.03–0.63; p = 0.009). In mixed model, the regression coefficient for fluid overload status (r² = 1.16; p = 0.014) indicated that the slope for SOFA score kinetic was less pronounced for patients with FO than for patients without FO.

Conclusions

FO patients had a more prolonged multi-organ failure according to SOFA score kinetics during septic shock from resuscitation phase to day 5.

Electronic supplementary material

The online version of this article (10.1186/s40560-019-0394-0) contains supplementary material, which is available to authorized users.

Association of Age With Short-term and Long-term Mortality Among Patients Discharged From Intensive Care Units in France

IMPORTANCE

An aging population is increasing the need for intensive care unit (ICU) beds. The benefit of ICU admission for elderly patients remains a subject of debate; however, long-term outcomes across all adult age strata are unknown.

OBJECTIVE

To describe short-term and long-term mortality (up to 3 years after discharge) across age strata in adult patients admitted to French ICUs.

DESIGN, SETTING, AND PARTICIPANTS

Using data extracted from the French national health system database, this cohort study determined in-hospital mortality and mortality at 3 months and 3 years after discharge of adult patients (older than 18 years) admitted to French ICUs from January 1 to December 31, 2013, focusing on age strata. The dates of analysis were November 2017 to December 2018.

EXPOSURE

Intensive care unit admission.

MAIN OUTCOMES AND MEASURES

In-hospital mortality and mortality at 3 months and 3 years after hospital discharge.

RESULTS

The study included 133 966 patients (median age, 65 years [interquartile range, 53-76 years); 59.9% male). Total in-hospital mortality was 19.0%, and 3-year mortality was 39.7%. For the 108 539 patients discharged alive from the hospital, 6.8% died by 3 months, and 25.8% died by 3 years after hospital discharge. After adjustment for sex, comorbidities, reason for hospitalization, and organ support (invasive ventilation, noninvasive ventilation, vasopressors, inotropes, fluid resuscitation, blood products administration, cardiopulmonary resuscitation, renal replacement therapy, and mechanical circulatory support), risk of mortality increased progressively across all age strata but with a sharp increase in those 80 years and older. In-hospital and 3-year postdischarge mortality rates, respectively, were 30.5% and 44.9% in patients 80 years and older compared with 16.5% and 22.5% in those younger than 80 years. Total 3-year mortality was 61.4% among patients 80 years and older vs 35.1% in those younger than 80. After age and sex standardization, excess mortality was highest among young patients during their first year after hospital discharge and persisted into the second and third years. In contrast, the mortality risk was close to the general population risk among elderly patients (≥80 years). Age and reason for hospitalization were strongly associated with long-term mortality (9-, 13-, and 20-fold increase in the risk of death 3 years after ICU discharge in patients aged 80-84, 85-89, and ≥90 years, respectively, compared with patients aged <35 years), while organ support use during ICU showed a weaker association (all organ support had 1.3-fold or lower increase in the risk of death).

CONCLUSIONS AND RELEVANCE

Results of this study suggest that aging was associated with an increased risk of mortality in the 3 years after hospital discharge that included an ICU admission, with a sharp increase in those 80 years and older. However, compared with the general population matched by age and sex, excess long-term mortality was high in young surviving patients but not in elderly patients.

A double-blind, placebo-controlled, randomised, multicentre, proof-of-concept and dose-finding phase II clinical trial to investigate the safety, tolerability and efficacy of adrecizumab in patients with septic shock and elevated adrenomedullin concentration (AdrenOSS-2)

INTRODUCTION

Sepsis remains a major health problem with an increasing incidence, high morbidity and high mortality. Apart from treatment with antibiotics and organ support, no approved specific adjunct therapies currently exist. Adrenomedullin (ADM) is a vasoactive peptide. High plasma concentrations of ADM correlate with worse outcome in sepsis patients. Preclinical work with the non-neutralising ADM-binding antibody adrecizumab showed promising effects in animal models of septic shock, including improved vascular barrier function, reduced vasopressor demand and organ dysfunction and increased survival. Therapeutic use of adrecizumab may therefore improve outcome in critically ill patients with septic shock and high ADM plasma concentrations. Phase I studies in healthy volunteers did not reveal any safety concerns. In this biomarker-guided trial, the safety and efficacy of adrecizumab will be investigated in patients with septic shock.

METHODS AND ANALYSIS

We describe a phase II, randomised, double-blind, placebo-controlled, biomarker-guided, proof-of-concept and dose-finding clinical trial in patients with early septic shock and high concentration of circulating ADM. A total of 300 patients will be enrolled at approximately 30 sites within the European Union. Patients are randomised to receive active treatment (2 and 4 mg/kg adrecizumab) or placebo, in a 1:1:2 ratio. Patient selection is guided by clinical parameters, and biomarker-guided by measurement of circulating biologically active ADM concentration at admission. Primary endpoint is safety and tolerability of adrecizumab over a 90-day period. A key secondary endpoint is the Sepsis Severity Index over a 14-day period.

ETHICS AND DISSEMINATION

This study is approved by relevant institutional review boards/independent ethics committees and is conducted in accordance with the ethical principles of the Declaration of Helsinki, the European Medicines Agency guidelines of Good Clinical Practice and all other applicable regulations. Results of this study will be published in a peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBER

NCT03085758; Pre-results.

[Epistemology in the intensive care unit-what is the purpose of a definition? : Paradigm shift in sepsis research]

The adoption of the new sepsis definition in early 2016 introduced a new paradigm for the clinical picture of sepsis. Up until now, sepsis was defined as a systemic inflammatory reaction (systemic inflammatory response syndrome, SIRS) to an infection. Based on a better understanding of the molecular mechanisms, the focus of the new definition is no longer the inflammatory response, but rather the tissue damage and impairment of organ function which this induces. The paradigm thus moves away from the infection and the systemic inflammatory response, and toward that which makes sepsis so dangerous in terms of both disease dynamics and outcome: organ failure due to a dysregulated host response to an infection. This change of perspective or paradigm enables patients with an increased risk of developing sepsis to be recognized and treated earlier in clinical routine, even outside of the intensive care unit. The new definition also promotes development of new treatment strategies with improved ability to treat sepsis causally.

Exploring the Protective Role and the Mechanism of Sphingosine 1 Phosphate in Endotoxic Cardiomyocytes

FTY720 is a sphingosine 1 phosphate (S1P) receptor agonist approved for the treatment of multiple sclerosis, which is a chronic inflammatory autoimmune disorder. Sepsis is a complex syndrome associated with progressive endotoxemic developments, which finally leads to damage of multiple organs, including the heart. In critical patients, cardiovascular dysfunction due to sepsis is a major cause of death. Previous studies have shown an association between S1P and cardioprotection in the situation of ischemia reperfusion and myocardial infarction. Therefore, we will study the role of S1P towards endotoxic cardiomyocytes. Different doses of FTY720 were applied or not to endotoxic cardiomyocytes. The concentration of inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 was measured by enzyme-linked immuno sorbent assay. Western blotting was used to analyze the downstream signaling pathways. We discovered that FTY720 reduced the levels of TNF-α and IL-6 through the NF-ΚB pathway, inhibited the expression of caspase-3, and activated both protein kinase B and extracellular signal-regulated kinase 1/2. Additionally, the activation of protein kinase B and extracellular signal-regulated kinase 1/2 could be inhibited by the S1P1 and S1P3 receptor antagonist vulcanized polyethylene23019. Therefore, we infer that S1P exerts a protective effect towards endotoxic cardiomyocytes by decreasing the levels of TNF-α and IL-6, regulating apoptotic and survival signaling pathway. The S1P1 and S1P3 receptors are involved in the prosurvival signal activation.

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.

Is There a Role for Hematopoietic Growth Factors During Sepsis?

Sepsis is a complex syndrome characterized by simultaneous activation of pro- and anti-inflammatory processes. After an inflammatory phase, patients present signs of immunosuppression and possibly persistent inflammation. Hematopoietic growth factors (HGFs) are glycoproteins that cause immune cells to mature and/or proliferate. HGFs also have a profound effect on cell functions and behavior. HGFs play crucial role in sepsis pathophysiology and were tested in several clinical trials without success to date. This review summarizes the role played by HGFs during sepsis and their potential therapeutic role in the Management of sepsis-related immune disturbances.

Six subphenotypes in septic shock: Latent class analysis of the PROWESS Shock study

PURPOSE

Septic shock is a highly heterogeneous condition which is part of the challenge in its diagnosis and treatment. In this study we aim to identify clinically relevant subphenotypes of septic shock using a novel statistic al approach.

METHODS

Baseline patient data from a large global clinical trial of septic shock (n = 1696) was analysed using latent class analysis (LCA). This approach allowed investigators to identify subgroups in a heterogeneous population by estimating a categorical latent variable that detects relatively homogeneous subgroups within a complex phenomenon.

RESULTS

LCA identified six different, clinically meaningful subphenotypes of septic shock each with a typical profile: (1) "Uncomplicated Septic Shock, (2) "Pneumonia with adult respiratory distress syndrome (ARDS)", (3) "Postoperative Abdominal", (4) "Severe Septic Shock", (5): "Pneumonia with ARDS and multiple organ dysfunction syndrome (MODS)", (6) "Late Septic Shock". The 6-class solution showed high entropy approaching 1 (i.e., 0.92), indicating there was excellent separation between estimated classes.

CONCLUSIONS

LCA appears to be an applicable statistical tool in analysing a heterogenous clinical cohort of septic shock. The results may lead to a better understanding of septic shock complexity and form a basis for considering targeted therapies and selecting patients for future clinical trials.

Clinical research in critical care. Difficulties and perspectives

In the field of Intensive Care Medicine, improved survival has resulted from better patient care, the early detection of clinical deterioration, and the prevention of iatrogenic complications, while research on new treatments has been followed by an overwhelming number of disappointments. The origins of these fiascos must be sought in the conjunction of methodological problems - common to other disciplines - and the particularities of critically ill patients. The present article discusses both aspects and suggests some options for progress.

Delayed Second Dose Antibiotics for Patients Admitted From the Emergency Department With Sepsis: Prevalence, Risk Factors, and Outcomes

OBJECTIVE

1) Determine frequency and magnitude of delays in second antibiotic administration among patients admitted with sepsis; 2) Identify risk factors for these delays; and 3) Exploratory: determine association between delays and patient-centered outcomes (mortality and mechanical ventilation after second dose).

DESIGN

Retrospective, consecutive sample sepsis cohort over 10 months.

SETTING

Single, tertiary, academic medical center.

PATIENTS

All patients admitted from the emergency department with sepsis or septic shock (defined: infection, ≥ 2 systemic inflammatory response syndrome criteria, hypoperfusion/organ dysfunction) identified by a prospective quality initiative.

EXCLUSIONS

less than 18 years old, not receiving initial antibiotics in the emergency department, death before antibiotic redosing, and patient refusing antibiotics.

INTERVENTIONS

We determined first-to-second antibiotic time and delay frequency. We considered delay major for first-to-second dose time greater than or equal to 25% of the recommended interval. Factors of interest were demographics, recommended interval length, comorbidities, clinical presentation, location at second dose, initial resuscitative care, and antimicrobial activity mechanism.

MEASUREMENTS AND MAIN RESULTS

Of 828 sepsis cases, 272 (33%) had delay greater than or equal to 25%. Delay frequency increased dose dependently with shorter recommended interval: 11 (4%) delays for 24-hour intervals (median time, 18.52 hr); 31 (26%) for 12-hour intervals (median, 10.58 hr); 117 (47%) for 8-hour intervals (median, 9.60 hr); and 113 (72%) for 6-hour intervals (median, 9.55 hr). In multivariable regression, interval length significantly predicted major delay (12 hr: odds ratio, 6.98; CI, 2.33-20.89; 8 hr: odds ratio, 23.70; CI, 8.13-69.11; 6 hr: odds ratio, 71.95; CI, 25.13-206.0). Additional independent risk factors were inpatient boarding in the emergency department (odds ratio, 2.67; CI, 1.74-4.09), initial 3-hour sepsis bundle compliance (odds ratio, 1.57; CI, 1.07-2.30), and older age (odds ratio, 1.16 per 10 yr, CI, 1.01-1.34). In the exploratory multivariable analysis, major delay was associated with increased hospital mortality (odds ratio, 1.61; CI, 1.01-2.57) and mechanical ventilation (odds ratio, 2.44; CI, 1.27-4.69).

CONCLUSIONS

Major second dose delays were common, especially for patients given shorter half-life pharmacotherapies and who boarded in the emergency department. They were paradoxically more frequent for patients receiving compliant initial care. We observed association between major second dose delay and increased mortality, length of stay, and mechanical ventilation requirement.

Appropriate endpoints for evaluation of new antibiotic therapies for severe infections: a perspective from COMBACTE's STAT-Net

PURPOSE

In this era of rising antimicrobial resistance, slowly refilling antibiotic development pipelines, and an aging population, we need to ensure that randomized clinical trials (RCTs) determine the added benefit of new antibiotic agents effectively and in a valid way, especially for severely ill patients. Unfortunately, universally accepted endpoints for the evaluation of new drugs in severe infections are lacking.

METHODS

We review and discuss the current practices and challenges regarding endpoints in RCTs in this field and propose novel approaches.

RESULTS

Usual endpoints actually recommended for drug development suffer from important flaws. Mortality requires large sample size and only partly related to the infectious process. Clinical cure rate is highly subjective in critically ill patients where symptoms may be related to other intercurrent events. Currently, composite endpoints, hierarchical nested designs, and competing risks analysis seem to be the most promising new tools for designing and analyzing clinical trials in this area, although they require further validation.

CONCLUSION

Regulatory authorities, pharmaceutical companies, and clinicians need to agree on the most appropriate clinical endpoints for severe infections to ensure efficient approval of new, effective antibiotic agents.

Antibacterial and detoxifying activity of NZ17074 analogues with multi-layers of selective antimicrobial actions against Escherichia coli and Salmonella enteritidis

NZ17074 (N1), an arenicin-3 derivative isolated from the lugworm, has potent antibacterial activity and is cytotoxic. To reduce its cytotoxicity, seven N1 analogues with different structures were designed by changing their disulfide bonds, hydrophobicity, or charge. The “rocket” analogue-N2 and the “kite” analogue-N6 have potent activity and showed lower cytotoxicity in RAW264.7 cells than N1. The NMR spectra revealed that N1, N2, and N6 adopt β-sheet structures stabilized by one or two disulfide bonds. N2 and N6 permeabilized the outer/inner membranes of E. coli, but did not permeabilize the inner membranes of S. enteritidis. N2 and N6 induced E. coli and S. enteritidis cell cycle arrest in the I-phase and R-phase, respectively. In E. coli and in S. enteritidis, 18.7–43.8% of DNA/RNA/cell wall synthesis and 5.7–61.8% of DNA/RNA/protein synthesis were inhibited by the two peptides, respectively. Collapsed and filamentous E. coli cells and intact morphologies of S. enteritidis cells were observed after treatment with the two peptides. Body weight doses from 2.5–7.5 mg/kg of N2 and N6 enhanced the survival rate of peritonitis- and endotoxemia-induced mice; reduced the serum IL-6, IL-1β and TNF-α levels; and protected mice from lipopolysaccharide-induced lung injury. These data indicate that N2 and N6, through multiple selective actions, may be promising dual-function candidates as novel antimicrobial and anti-endotoxin peptides.

New Consensus Definitions for Sepsis and Septic Shock: Implications for Treatment Strategies and Drug Development?

Sepsis continues to escape a precise diagnostic definition. The most recent consensus definition, termed Sepsis-3, highlights the importance of the maladaptive and potentially life-threatening host response to infection. After briefly reviewing the history and epidemiology of sepsis, we go on to describe some of the challenges encountered when classifying such a heterogenous disease state. In the context of these new definitions for sepsis and septic shock, we explore current and potentially novel therapies, and conclude by mentioning some of the controversies of this most recent framework.

Outcomes in necrotizing soft tissue infections treated with therapeutic plasma exchange

BACKGROUND

Treatment of necrotizing soft tissue infections (NSTIs) includes prompt surgical debridement and antibiotics, but despite standard care, the morbidity and mortality remain high. Since therapeutic plasma exchange (TPE) has been considered for treatment of severe sepsis, this study evaluates the efficacy of TPE for patients with NSTI.

STUDY DESIGN AND METHODS

This is a retrospective study of patients with diagnosis of NSTI who received treatment with and without TPE over an 11-year period. The primary outcome was in-hospital mortality.

RESULTS

Fifty-two patients with NSTI treated with TPE (TPE group) and 125 patients with NSTI not treated with TPE (non-TPE group) were assessed. Nineteen (36.5%) patients died in the TPE group, and 35 (28%) patients died in the non-TPE group. Within the TPE group, there was significant improvement in white blood cell (WBC) count and sodium levels 7 days after TPE treatment, but no improvement in creatinine. Inverse probability weighting based on propensity scores was used to compare survival in the TPE and non-TPE groups and demonstrated that TPE was associated with an increased odds of death (odds ratio, 2.8). A second analysis matched for six variables yielded 31 pairs and demonstrated no significant difference in mortality or length of stay.

CONCLUSIONS

This study describes the largest series of patients with NSTIs treated with TPE and showed no evidence of clinical benefit. Further carefully designed studies with meaningful clinical endpoints would prove useful in assessing reproducibility and determining if there is a role for TPE in other forms of severe sepsis.

Pro-Resolving Molecules-New Approaches to Treat Sepsis?

Inflammation is a complex response of the body to exogenous and endogenous insults. Chronic and systemic diseases are attributed to uncontrolled inflammation. Molecules involved in the initiation of inflammation are very well studied while pathways regulating its resolution are insufficiently investigated. Approaches to down-modulate mediators relevant for the onset and duration of inflammation are successful in some chronic diseases, while all of them have failed in sepsis patients. Inflammation and immune suppression characterize sepsis, indicating that anti-inflammatory strategies alone are inappropriate for its therapy. Heme oxygenase 1 is a sensitive marker for oxidative stress and is upregulated in inflammation. Carbon monoxide, which is produced by this enzyme, initiates multiple anti-inflammatory and pro-resolving activities with higher production of omega-3 fatty acid-derived lipid metabolites being one of its protective actions. Pro-resolving lipids named maresins, resolvins and protectins originate from the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid while lipoxins are derived from arachidonic acid. These endogenously produced lipids do not simply limit inflammation but actively contribute to its resolution, and thus provide an opportunity to combat chronic inflammatory diseases and eventually sepsis.

Early sepsis bundle compliance for non-hypotensive patients with intermediate versus severe hyperlactemia

OBJECTIVE

To compare the association of 3-h sepsis bundle compliance with hospital mortality in non-hypotensive sepsis patients with intermediate versus severe hyperlactemia.

METHODS

This was a cohort study of all non-hypotensive, hyperlactemic sepsis patients captured in a prospective quality-improvement database, treated October 2014 to September 2015 at five tertiary-care centers. We defined sepsis as 1) infection, 2) ≥2 SIRS criteria, and 3) ≥1 organ dysfunction criterion. "Time-zero" was the first time a patient met all sepsis criteria.

INCLUSION CRITERIA

systolic blood pressure>90 mmHg, mean arterial pressure>65 mmHg, and serum lactate≥2.2 mmol/L. Primary exposures: 1) intermediate(2.2-3.9 mmol/L) versus severe(≥4.0 mmol/L) hyperlactemia and 2) full 3-h bundle compliance. Bundle elements: The primary outcome was 60-day in-hospital mortality.

RESULTS

2417 patients met inclusion criteria. 704(29%) had lactate≥4.0 mmol/L versus 1775 patients with lactate 2.2-3.9 mmol/L. Compliance was 75% for antibiotics and 53% for fluids. Full-compliance was comparable between lactate groups (n=200(29%) and 488(28%), respectively). We observed 424(17.5%) mortalities: intermediate/non-compliant - 182(14.9%), intermediate/compliant - 41(8.4%), severe/non-compliant - 147(29.2%), severe/compliant - 54(27.0%) [difference-of-differences=4.3%, CI=2.6-5.9%]. In multivariable regression, mortality predictors included severe hyperlactemia (OR=1.99, CI=1.51-2.63) and bundle compliance (OR=0.62, CI=0.42-0.90), and their interaction was significant: p_{(interaction)}=0.022.

CONCLUSION

We observed a significant interaction between 3-h bundle compliance and initial hyperlactemia. Bundle compliance may be associated with greater mortality benefit for non-hypotensive sepsis patients with less severe hyperlactemia.

Reasons for death in patients with sepsis and septic shock

PURPOSE

Understanding the underlying cause of mortality in sepsis has broad implications for both clinical care and interventional trial design. However, reasons for death in sepsis remain poorly understood. We sought to characterize reasons for in-hospital mortality in a population of patients with sepsis or septic shock.

MATERIALS AND METHODS

We performed a retrospective review of patients admitted to the intensive care unit with sepsis or septic shock who died during their index admission. Reasons for death were classified into 6 categories determined a priori by group consensus. Interrater reliability was calculated and Fleiss κ reported. The associations between selected patient characteristics (eg, serum lactate) and reason for death were also assessed.

RESULTS

One hundred fifteen patients were included. Refractory shock (40%) and comorbid withdrawal of care (44%) were the most common reasons for death. Overall interrater agreement was substantial (κ = 0.61, P<.01). Lactate was higher in patients who died because of refractory shock as compared with those who died for other reasons (4.7 vs 2.8 mmol/L, P<.01).

CONCLUSION

In this retrospective cohort, refractory shock and comorbid withdrawal of care were the most common reasons for death. Following prospective validation, the classification methodology presented here may be useful in the design/interpretation of trials in sepsis.

Genomics and pharmacogenomics of sepsis: so close and yet so far

Sapru et al. show in this issue of Critical Care that variants of thrombomodulin and the endothelial protein C receptor, but not protein C, are associated with mortality and organ dysfunction (ventilation-free and organ failure-free days) in ARDS. Hundreds of gene variants have been found prognostic in sepsis. However, none of these prognostic genomic biomarkers are used clinically. Predictive biomarker discovery (pharmacogenomics) usually follows a candidate gene approach, utilizing knowledge of drug pathways. Pharmacogenomics could be applied to enhance efficacy and safety of drugs used for treatment of sepsis (e.g., norepinephrine, epinephrine, vasopressin, and corticosteroids). Pharmacogenomics can enhance drug development in sepsis, which is very important because there is no approved drug for sepsis. Pharmacogenomics biomarkers must pass three milestones: scientific, regulatory, and commercial. Huge challenges remain but great opportunities for pharmacogenomics of sepsis are on the horizon.