The effect of polymyxin B hemoperfusion on modulation of human leukocyte antigen DR in severe sepsis patients

The role of polymyxin B-immobilized hemoperfusion in reducing mortality and enhancing hemodynamics in patients with sepsis and septic shock: A systematic review and meta-analysis

Purpose

Polymyxin B-immobilized hemoperfusion (PMX-HP) is a therapeutic strategy for removing circulating endotoxins from patients with sepsis or septic shock. However, the survival advantage of PMX-HP treatment remains controversial for patients with sepsis/septic shock. Therefore, this study collected all the clinical trials to assess the effect and the safety of PMX-HP treatment.

Methods

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for eligible trials fromtheir inception through June 30, 2023. All clinical trials that investigated the effect of polymyxin B hemoperfusion in patients who died with sepsis or septic shock within 28-day mortality were eligible. The Cochrane Risk of Bias Assessment instrument and the ROBINS-I tool were used to assess the risk of bias.

Results

A total of 30 trials, including 25680 adult patients, were included. PMX-HP decreased 28-day mortality (OR 0.75, 95 % CI 0.65-0.88; p＜0.00001). Subgroup analysis revealed that 28-day mortality was significantly reduced after PMX-HP treatment in the mixed infection site group and in the age under 70 years old group. PMX-HP might also lower endotoxin levels (MD -1.22, 95 % CI -1.62 - 0.81, p < 0.00001) and improve SOFA scores (MD -2.11, 95 % CI -3.80- 0.43, p = 0.01). PMX-HP was not linked to the development of significant adverse events (p = 0. 05).

Conclusion

Our findings suggest that PMX-HP therapy can reduce 28-day mortality in individuals with sepsis or septic shock. The therapeutic effect may be due to the ability of PMX-HP to lower endotoxin levels and enhance hemodynamics. However, further assessment of the clinical effects of PMX-HP on sepsis or septic shock is required.

Blood Purification for Adult Patients With Severe Infection or Sepsis/Septic Shock: A Network Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

This study aimed to conduct a comprehensive and updated systematic review with network meta-analysis (NMA) to assess the outcome benefits of various blood purification modalities for adult patients with severe infection or sepsis.

DATA SOURCES

We conducted a search of PubMed, MEDLINE, clinical trial registries, Cochrane Library, and Embase databases with no language restrictions.

STUDY SELECTION

Only randomized controlled trials (RCTs) were selected.

DATA EXTRACTION

The primary outcome was overall mortality. The secondary outcomes were the length of mechanical ventilation (MV) days and ICU stay, incidence of acute kidney injury (AKI), and kidney replacement therapy requirement.

DATA SYNTHESIS

We included a total of 60 RCTs with 4,595 participants, comparing 16 blood purification modalities with 17 interventions. Polymyxin-B hemoperfusion (relative risk [RR]: 0.70; 95% CI, 0.57-0.86) and plasma exchange (RR: 0.61; 95% CI, 0.42-0.91) were associated with low mortality (very low and low certainty of evidence, respectively). Because of the presence of high clinical heterogeneity and intransitivity, the potential benefit of polymyxin-B hemoperfusion remained inconclusive. The analysis of secondary outcomes was limited by the scarcity of available studies. HA330 with high-volume continuous venovenous hemofiltration (CVVH), HA330, and standard-volume CVVH were associated with shorter ICU stay. HA330 with high-volume CVVH, HA330, and standard-volume CVVH were beneficial in reducing MV days. None of the interventions showed a significant reduction in the incidence of AKI or the need for kidney replacement therapy.

CONCLUSIONS

Our NMA suggests that plasma exchange and polymyxin-B hemoperfusion may provide potential benefits for adult patients with severe infection or sepsis/septic shock when compared with standard care alone, but most comparisons were based on low or very low certainty evidence. The therapeutic effect of polymyxin-B hemoperfusion remains uncertain. Further RCTs are required to identify the specific patient population that may benefit from extracorporeal blood purification.

Endotoxin removal therapy with Polymyxin B immobilized fiber column: a single center experience from EUPHAS2 registry

Although the precise clinical indication for initiation of PMX-HA is widely debated in the literature, a proper patient selection and timing of treatment delivery might play a critical role in the clinical course of a specific subphenotype of septic shock (endotoxic shock). In light of this view, since 2019, we have introduced in our clinical practice a diagnostic-therapeutic flowchart to select patients that can benefit the most from the treatment proposed. In addition, we reported in this study our experience of PMX-HA in a cohort of critically ill patients admitted to our intensive care unit (ICU). We analyzed a single centre, retrospective, observational web-based database (extracted from the EUPHAS2 registry) of critically ill patients admitted to the ICU between January 2016 and May 2021 who were affected by endotoxic shock. Patients were divided according to the diagnostic-therapeutic flowchart in two groups: Pre-Flowchart (Pre-F) and Post-Flowchart (Post-F). From January 2016 to May 2021, 61 patients were treated with PMX-HA out of 531 patients diagnosed with septic shock and of these, fifty patients (82%) developed AKI during their ICU stay. The most common source of infection was secondary peritonitis (36%), followed by community-acquired pneumonia (29%). Fifty-five (90%) out of 61 patients received a second PMX-HA treatment, with a statistically significant difference between the two groups (78% of the Pre-F vs. 100% of the Post-F group, p = 0.005). In both groups, between T0 and T120, the Endotoxin Activity Assay (EAA) decreased, while the SOFA score, mean arterial pressure (MAP), and Vasoactive Inotropic Score (VIS) improved with no statistically significant difference. Furthermore, when performing a propensity score matching analysis to compare mortality between the two groups, statistically significant lower ICU and 90-day mortalities were observed in the Post-F group [p = 0.016]. Although in this experienced centre data registry, PMX-HA was associated with organ function recovery, hemodynamic improvement, and current EAA level reduction in critically ill patients with endotoxic shock. Following propensity score-matched analysis, ICU mortality and 90-day mortalities were lower in the diagnostic-therapeutic flowchart group when considering two temporal groups based on strict patient selection criteria and timing to achieve PMX. Further Randomised Control Trials focused on centre selection, adequate training and a flowchart of action when assessing extracorporeal blood purification use should be performed.

Derivation and elimination of uremic toxins from kidney-gut axis

Uremic toxins are chemicals, organic or inorganic, that accumulate in the body fluids of individuals with acute or chronic kidney disease and impaired renal function. More than 130 uremic solutions are included in the most comprehensive reviews to date by the European Uremic Toxins Work Group, and novel investigations are ongoing to increase this number. Although approaches to remove uremic toxins have emerged, recalcitrant toxins that injure the human body remain a difficult problem. Herein, we review the derivation and elimination of uremic toxins, outline kidney-gut axis function and relative toxin removal methods, and elucidate promising approaches to effectively remove toxins.

Involvement of Innate Immune System in the Pathogenesis of Sepsis-Associated Acute Kidney Injury

Although experimental models have shown that the innate immune system is a main contributor to acute kidney injury (AKI), its involvement in human sepsis-associated AKI (SA-AKI) remains unclear. We retrospectively evaluated 19 patients with SA-AKI who were treated with continuous renal replacement therapy (CRRT). Serum cytokine, complement components, and the proportion and functions of innate immune cells, such as CD56+ T cells, CD56+ natural killer (NK) cells, and monocytes, were analyzed. There were no differences in the proportions of CD56+ T and NK cells between patients with SA-AKI and healthy controls. In patients with SA-AKI, fas ligand (FasL) expression in CD56+ T cells was significantly upregulated, and the proportion of perforin-positive CD56+ T cells tended to be higher than that in healthy controls. The positive rate of both FasL and perforin of CD56+ T cells was significantly higher than that of CD56- T cells, which include cytotoxic T cells. Antigen-presenting capacity and phagocytic activity of monocytes in patients with SA-AKI were significantly decreased compared to those of healthy controls and did not recover soon after the initiation of CRRT. CD56+ T cells are involved in the disease processes of human SA-AKI through effector molecules such as FasL or perforin.

Endotoxin activity trend and multi-organ dysfunction in critically ill patients with septic shock, who received Polymyxin-B hemadsorption: A multicenter, prospective, observational study

BACKGROUND

The baseline endotoxin activity (EAT0) may predict the outcome of critically ill septic patients who receive Polymyxin-B hemadsorption (PMX-HA), however, the clinical implications of specific EA trends remain unknown.

METHODS

Subgroup analysis of the prospective, multicenter, observational study EUPHAS2. We included 50 critically ill patients with septic shock and EAT0 ≥ 0.6, who received PMX-HA. The primary outcome of the study was the EA and SOFA score progression from T0 to 120 h afterwards (T120). Secondary outcomes included the EA and SOFA score progression in whom had EA at 48 h (EAT48) < 0.6 (EA responders, EA-R) versus who had not (EA non-responders, EA-NR).

RESULTS

Septic shock was mainly caused by 27 abdominal (54%) and 17 pulmonary (34%) infections, predominantly due to Gram negative bacteria (39 patients, 78%). The SAPS II score was 67.5 [52.8-82.3] and predicted a mortality rate of 75%. Between T0 and T120, the EA decreased (p < 0.001), while the SOFA score and the Inotropic Score (IS) improved (p < 0.001). In comparison with EA-NR (18 patients, 47%), the EA-R group (23 patients, 53%) showed faster IS improvement and lower requirement of continuous renal replacement therapy (CRRT) during the ICU stay. Overall hospital mortality occurred in 18 patients (36%).

CONCLUSIONS

In critically ill patients with septic shock and EAT0 ≥ 0.6 who received PMX-HA, EA decreased and SOFA score improved over 120 h. In whom high EA resolved within 48 h, IS improvement was faster and CRRT requirement was lower compared with patients with EAT48 ≥ 0.6.

Bacterial extracellular vesicles repress the vascular protective factor RNase1 in human lung endothelial cells

BACKGROUND

Sepsis is one of the leading causes of death worldwide and characterized by blood stream infections associated with a dysregulated host response and endothelial cell (EC) dysfunction. Ribonuclease 1 (RNase1) acts as a protective factor of vascular homeostasis and is known to be repressed by massive and persistent inflammation, associated to the development of vascular pathologies. Bacterial extracellular vesicles (bEVs) are released upon infection and may interact with ECs to mediate EC barrier dysfunction. Here, we investigated the impact of bEVs of sepsis-related pathogens on human EC RNase1 regulation.

METHODS

bEVs from sepsis-associated bacteria were isolated via ultrafiltration and size exclusion chromatography and used for stimulation of human lung microvascular ECs combined with and without signaling pathway inhibitor treatments.

RESULTS

bEVs from Escherichia coli, Klebsiella pneumoniae and Salmonella enterica serovar Typhimurium significantly reduced RNase1 mRNA and protein expression and activated ECs, while TLR2-inducing bEVs from Streptococcus pneumoniae did not. These effects were mediated via LPS-dependent TLR4 signaling cascades as they could be blocked by Polymyxin B. Additionally, LPS-free ClearColi™ had no impact on RNase1. Further characterization of TLR4 downstream pathways involving NF-кB and p38, as well as JAK1/STAT1 signaling, revealed that RNase1 mRNA regulation is mediated via a p38-dependent mechanism.

CONCLUSION

Blood stream bEVs from gram-negative, sepsis-associated bacteria reduce the vascular protective factor RNase1, opening new avenues for therapeutical intervention of EC dysfunction via promotion of RNase1 integrity. Video Abstract.

Effects of hemoperfusion first aid process reengineering on electrolyte disturbance, liver function and prognosis in patients with acute poisoning

Acute poisoning is a frequently encountered medical emergency in the emergency room, typically resulting from the incorrect use of drugs or pesticides, and is characterized by sudden onset of severe symptoms, often leading to fatalities. This research was to explore the effect of hemoperfusion first aid process reengineering on electrolyte disturbance, liver function and prognosis in patients with acute poisoning. From August 2019 to July 2021, 137 patients with acute poisoning who received first aid process reengineering were selected as the observation group, and 151 patients with acute poisoning who received routine first aid were selected as the control group. The success rate, first aid-related indicators, electrolyte, liver function, and prognosis and survival were recorded after first aid treatment. The observation group had a 100% effective rate on the third day of first aid, which was significantly higher than the control group (91.39%). The observation group also had shorter time for emesis induction, poisoning assessment, venous transfusion, consciousness recovery, opening of the blood purification circuit, and start of hemoperfusion than the control group (P < 0.05). Additionally, the observation group showed lower levels of alpionine aminotransferase, total bilirubin, serum creatinine, and urea nitrogen after treatment, and a significantly lower mortality rate (6.57%) than the control group (26.28%) (P < 0.05). Hemoperfusion first aid process reengineering in patients with acute poisoning can improve the success rate of first aid, shorten the time of first aid, improve the electrolyte disturbance, treatment effect, liver function and blood routine of the patients.

The Regulation of Neutrophil Migration in Patients with Sepsis: The Complexity of the Molecular Mechanisms and Their Modulation in Sepsis and the Heterogeneity of Sepsis Patients

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Common causes include gram-negative and gram-positive bacteria as well as fungi. Neutrophils are among the first cells to arrive at an infection site where they function as important effector cells of the innate immune system and as regulators of the host immune response. The regulation of neutrophil migration is therefore important both for the infection-directed host response and for the development of organ dysfunctions in sepsis. Downregulation of CXCR4/CXCL12 stimulates neutrophil migration from the bone marrow. This is followed by transmigration/extravasation across the endothelial cell barrier at the infection site; this process is directed by adhesion molecules and various chemotactic gradients created by chemotactic cytokines, lipid mediators, bacterial peptides, and peptides from damaged cells. These mechanisms of neutrophil migration are modulated by sepsis, leading to reduced neutrophil migration and even reversed migration that contributes to distant organ failure. The sepsis-induced modulation seems to differ between neutrophil subsets. Furthermore, sepsis patients should be regarded as heterogeneous because neutrophil migration will possibly be further modulated by the infecting microorganisms, antimicrobial treatment, patient age/frailty/sex, other diseases (e.g., hematological malignancies and stem cell transplantation), and the metabolic status. The present review describes molecular mechanisms involved in the regulation of neutrophil migration; how these mechanisms are altered during sepsis; and how bacteria/fungi, antimicrobial treatment, and aging/frailty/comorbidity influence the regulation of neutrophil migration.

CytoSorb hemoperfusion markedly attenuates circulating cytokine concentrations during systemic inflammation in humans in vivo

BACKGROUND

The CytoSorb hemoadsorption device has been demonstrated to be capable of clearing inflammatory cytokines, but has not yet been shown to attenuate plasma cytokine concentrations. We investigated the effects of CytoSorb hemoperfusion on plasma levels of various cytokines using the repeated human experimental endotoxemia model, a highly standardized and reproducible human in vivo model of systemic inflammation and immunological tolerance induced by administration of bacterial lipopolysaccharide (LPS).

METHODS

Twenty-four healthy male volunteers (age 18-35) were intravenously challenged with LPS (a bolus of 1 ng/kg followed by continuous infusion of 0.5 ng/kg/hr for three hours) twice: on day 0 to quantify the initial cytokine response and on day 7 to quantify the degree of endotoxin tolerance. Subjects either received CytoSorb hemoperfusion during the first LPS challenge (CytoSorb group), or no intervention (control group). Plasma cytokine concentrations and clearance rates were determined serially. This study was registered at ClinicalTrials.gov (NCT04643639, date of registration November 24th 2020).

RESULTS

LPS administration led to a profound increase in plasma cytokine concentrations during both LPS challenge days. Compared to the control group, significantly lower plasma levels of tumor necrosis factor (TNF, - 58%, p < 0.0001), interleukin (IL)-6 ( - 71%, p = 0.003), IL-8 ( - 48%, p = 0.02) and IL-10 ( - 26%, p = 0.03) were observed in the CytoSorb group during the first LPS challenge. No differences in cytokine responses were observed during the second LPS challenge.

CONCLUSIONS

CytoSorb hemoperfusion effectively attenuates circulating cytokine concentrations during systemic inflammation in humans in vivo, whereas it does not affect long-term immune function. Therefore, CytoSorb therapy may be of benefit in conditions characterized by excessive cytokine release.

Rationale for sequential extracorporeal therapy (SET) in sepsis

Sepsis and septic shock remain drivers for morbidity and mortality in critical illness. The clinical picture of patients presenting with these syndromes evolves rapidly and may be characterised by: (a) microbial host invasion, (b) establishment of an infection focus, (c) opsonisation of bacterial products (e.g. lipopolysaccharide), (d) recognition of pathogens resulting in an immune response, (e) cellular and humoral effects of circulating pathogen and pathogen products, (f) immunodysregulation and endocrine effects of cytokines, (g) endothelial and organ damage, and (h) organ crosstalk and multiple organ dysfunction. Each step may be a potential target for a specific therapeutic approach. At various stages, extracorporeal therapies may target circulating molecules for removal. In sequence, we could consider: (a) pathogen removal from the circulation with affinity binders and cartridges (specific), (b) circulating endotoxin removal by haemoperfusion with polymyxin B adsorbers (specific), (c) cytokine removal by haemoperfusion with sorbent cartridges or adsorbing membranes (non-specific), (d) extracorporeal organ support with different techniques for respiratory and cardiac support (CO₂ removal or extracorporeal membrane oxygenation), and renal support (haemofiltration, haemodialysis, or ultrafiltration). The sequence of events and the use of different techniques at different points for specific targets will likely require trials with endpoints other than mortality. Instead, the primary objectives should be to achieve the desired action by using extracorporeal therapy at a specific point.

New Frontiers in Sepsis-Induced Acute Kidney Injury and Blood Purification Therapies: The Role of Polymethylmethacrylate Membrane Hemofilter

Acute kidney injury (AKI) is a common consequence of sepsis with a mortality rate of up to 40%. The pathogenesis of septic AKI is complex and involves several mechanisms leading to exacerbated inflammatory response associated with renal injury. A large body of evidence suggests that inflammation is tightly linked to AKI through bidirectional interaction between renal and immune cells. Preclinical data from our and other laboratories have identified in complement system activation a crucial mediator of AKI. Partial recovery following AKI could lead to long-term consequences that predispose to chronic dysfunction and may also accelerate the progression of preexisting chronic kidney disease. Recent findings have revealed striking morphological and functional changes in renal parenchymal cells induced by mitochondrial dysfunction, cell cycle arrest via the activation of signaling pathways involved in aging process, microvascular rarefaction, and early fibrosis. Although major advances have been made in our understanding of the pathophysiology of AKI, there are no available preventive and therapeutic strategies in this field. The identification of ideal clinical biomarkers for AKI enables prompt and effective therapeutic strategy that could prevent the progression of renal injury and promote repair process. Therefore, the use of novel biomarkers associated with clinical and functional criteria could provide early interventions and better outcome. Several new drugs for AKI are currently being investigated; however, the complexity of this disease might explain the failure of pharmacological intervention targeting just one of the many systems involved. The hypothesis that blood purification could improve the outcome of septic AKI has attracted much attention. New relevant findings on the role of polymethylmethacrylate-based continuous veno-venous hemofiltration in septic AKI have been reported. Herein, we provide a comprehensive literature review on advances in the pathophysiology of septic AKI and potential therapeutic approaches in this field.

Effect of extracorporeal hemoadsorption in critically ill patients with COVID-19: A narrative review

COVID-19 has been affecting the world unprecedentedly and will remain widely prevalent due to its elusive pathophysiological mechanism and the continuous emergence of new variants. Critically ill patients with COVID-19 are commonly associated with cytokine storm, multiple organ dysfunction, and high mortality. To date, growing evidence has shown that extracorporeal hemoadsorption can exert its adjuvant effect to standard of care by regulating immune homeostasis, reducing viremia, and decreasing endotoxin activity in critically ill COVID-19 cases. However, the selection of various hemofilters, timing of initiation and termination of hemoadsorption therapy, anticoagulation management of extracorporeal circuits, identification of target subgroups, and ultimate survival benefit remain controversial. The purpose of this narrative review is to comprehensively summarize the rationale for the use of hemoadsorption in critically ill patients with COVID-19 and to gather the latest clinical evidence in this field.

Cellular Immuno-Profile in Septic Human Host: A Scoping Review

Simple Summary

Septic shock is a life-threatening disease caused by a dysregulated host response to infection, affecting millions of people every year and killing more than 25% directly despite advances in modern medicine. This pathology is characterized by apoptosis-induced depletion of immune cells and immunodepression. Many alterations in the expression of surface markers of neutrophils and monocytes have been described in septic patients. There is no specific treatment but the early identification and diagnosis of the pathology as well as timely treatment can greatly improve patient outcomes. The aim of this study was to inspect the recently published literature to inform the clinician about the most up-to-date techniques for the study of immune cell phenotypes and on the function of leukocytes of extracorporeal and non-blood purification treatments proposed for sepsis were also analyzed. The most important alteration observed in septic neutrophils is the activation of a survival program capable of resisting apoptotic death. As regards adaptive immunity, sepsis-induced apoptosis leads to lymphopenia in patients with septic shock and this process involves all types of T cells (CD4, CD8 and Natural Killer), except for regulatory T cells, favoring immunosuppression. Several promising therapies that target the host’s immune response to sepsis are currently under evaluation.

Abstract

Innate and adaptive immune system cells play a critical role in the host response to sepsis. Sepsis is a life-threatening disease characterized by apoptosis-induced depletion of immune cells and immunodepression, which contribute to morbidity and mortality. Many alterations in the expression of surface markers of neutrophils and monocytes have been described in septic patients. The aim of this study was to inspect the recently published literature to inform the clinician about the most up-to-date techniques for the study of circulating leukocytes. The impact on cell phenotypes and on the function of leukocytes of extracorporeal and non-blood purification treatments proposed for sepsis were also analyzed. We conducted a systematic review using Pubmed/Medline, Ovid/Willey, the Cochrane Library, the Cochrane Controlled Trials Register, and EMBASE, combining key terms related to immunological function in sepsis and selected the most relevant clinical trials and review articles (excluding case reports) published in the last 50 years. The most important alteration in neutrophils during sepsis is that they activate an anti-apoptotic survival program. In septic monocytes, a reduced characteristic expression of HLA-DR is observed, but their role does not seem to be significantly altered in sepsis. As regards adaptive immunity, sepsis leads to lymphopenia and immunosuppression in patients with septic shock; this process involves all types of T cells (CD4, CD8 and Natural Killer), except for regulatory T cells, which retain their function. Several promising therapies that target the host immune response are currently under evaluation. During the worldwide pandemic caused by SARS-CoV-2, it was useful to study the “cytokine storm” to find additional treatments, such as the oXiris^® filter. This therapy can decrease the concentration of inflammatory markers that affect the severity of the disease.

Endotoxin removal therapy with Polymyxin B immobilized fiber column as a COVID-19-bedside strategy protocol for endotoxic shock

Endotoxin -induced sepsis is a leading cause of ICU mortality. From 1994 to the present, PMX-HP has been available as an adjuvant therapy for endotoxin removal and immunomodulation. The efficacy and usefulness of this therapy have been demonstrated for more than a quarter of a century and are partially supported by clinical studies. However, it appears that selected subgroups of patients with endotoxic shock and with appropriate timing could benefit. Endotoxemia may be involved in the pathophysiology of COVID-19, based on enterocyte dysfunction and malabsorptive syndrome. Due to the characteristics of the microbiota, Gram-negative bacteria or their fragments (i.e., endotoxin) may translocate into the systemic circulation leading to inflammatory activation, immune dysfunction, and sepsis. In addition, patients with severe forms of COVID-19 are at risk of superimposed infections. Endotoxemia can arise due to the translocation of Gram-negative bacteria or their fragments from the gut barrier. According to the most updated evidence available from large randomized trials, septic shock patients with MODS > 9 and EA levels ranging from 0.6 to 0.9 are those who may benefit the most from PMX-HP treatment in terms of improvement of survival. As shown in a previous publication, we believe that similarly to the source control, microbiological cultures, and antibiotics administration, EA evaluation at regular intervals, and the targeted use of PMX-HP could be lifesaving and adequate within the golden hour for the diagnosis and treatment of endotoxic shock. In our center, we applied a diagnostic-clinical flowchart also for endotoxic shock related to COVID-19.

Neutrophils in acute inflammation: current concepts and translational implications

Modulation of neutrophil recruitment and function is crucial for targeting inflammatory cells to sites of infection to combat invading pathogens while, at the same time, limiting host tissue injury or autoimmunity. The underlying mechanisms regulating recruitment of neutrophils, 1 of the most abundant inflammatory cells, have gained increasing interest over the years. The previously described classical recruitment cascade of leukocytes has been extended to include capturing, rolling, adhesion, crawling, and transmigration, as well as a reverse-transmigration step that is crucial for balancing immune defense and control of remote organ endothelial leakage. Current developments in the field emphasize the importance of cellular interplay, tissue environmental cues, circadian rhythmicity, detection of neutrophil phenotypes, differential chemokine sensing, and contribution of distinct signaling components to receptor activation and integrin conformations. The use of therapeutics modulating neutrophil activation responses, as well as mutations causing dysfunctional neutrophil receptors and impaired signaling cascades, have been defined in translational animal models. Human correlates of such mutations result in increased susceptibility to infections or organ damage. This review focuses on current advances in the understanding of the regulation of neutrophil recruitment and functionality and translational implications of current discoveries in the field with a focus on acute inflammation and sepsis.

Interaction of Lipopolysaccharide-Spiked Blood with Anti-Fouling Polymyxin B-Modified Glass

Bacterial endotoxin, also known as lipopolysaccharide (LPS), plays a major role in the initiation of sepsis, a severe inflammatory condition. Removal of the toxin from blood is one accepted method of patient treatment. Polymyxin B (PMB)-modified columns have been employed successfully for this purpose via extra-corporeal blood-flow systems that incorporate a cartridge for toxin removal. Herein we demonstrate that PMB-modified glass beads are able to reduce the presence of LPS competitively with the equivalent fiber column used in a commercial cartridge. Analysis by gas chromatography-mass spectrometry and ELISA of released fatty acids from the toxin indicates that PMB does not physically capture or significantly remove LPS from the blood samples. In reality, interaction between the surface-bound PMB and the toxin may lead to disaggregation or monomerization of LPS aggregates. As aggregates are the bioactive form of LPS, it is possible that the monomerization of these entities may be the mechanism by which their toxicity is reduced. Moreover, this work indicates that LPS monomers are stabilized subsequent to disaggregation induced by PMB.

Effects of Dietary Supplementation with Lactobacillus acidophilus and Bacillus subtilis on Mucosal Immunity and Intestinal Barrier Are Associated with Its Modulation of Gut Metabolites and Microbiota in Late-Phase Laying Hens

We investigated the effects of dietary supplementation with Lactobacillus acidophilus and Bacillus subtilis on the intestinal immune response, intestinal barrier function, cecal microbiota profile, and metabolite profile in late-phase laying hens. Hens were divided into three groups and fed with the basal diet (NC group), basal diet supplementation with 250 mg/kg B. subtilis and L. acidophilus mixture powder (LD group), and basal diet supplementation with 500 mg/kg B. subtilis and L. acidophilus mixture powder (HD group), respectively. The results indicated that the dietary supplementation with L. acidophilus and B. subtilis increased the integrity of the intestinal barrier as evidenced by the significant increase in the number of ileal goblet cells and improve the expression of occludin, claudin-1, and ZO-1 genes in the HD group. Moreover, the levels of IL-6, TNF-α, and IFN-γ were significantly decreased in the LD and HD groups. The levels of immunoglobulin G (IgG) increased in the LD and HD group, and the levels of secretory immunoglobulin A (sIgA) increased with the HD treatment. Furthermore, 16 s rRNA sequencing revealed L. acidophilus in combination with B. subtilis increased the diversity of gut microbiota. The metabolomic analysis revealed beneficial changes in the amino acid metabolism and lipid metabolism (decrease in LysoPC and LysoPE levels). In conclusion, dietary supplementation with L. acidophilus and B. subtilis could improve intestinal barrier function and maintain immune homeostasis. These beneficial effects may be associated with the modulation of the intestinal microbiome and metabolites.

Comparison of the Clinical Effectiveness of AN69-oXiris versus AN69-ST Filter in Septic Patients: A Single-Centre Study

INTRODUCTION

The clinical effectiveness of AN69-oXiris remains unclear. This study aimed to compare the effects of AN69-oXiris and AN69-ST filters on cytokine levels and clinical improvement in septic patients.

METHODS

This prospective observational study recruited septic patients who underwent blood purification in the First Affiliated Hospital of Soochow University between December 2019 and May 2020. Patients were assigned to an AN69-oXiris (oXiris) or AN69-ST (ST) group based on their preferred filter. Patients' clinical data, cytokine levels, and prognostic indicators were analysed at baseline (T0), 24 h after treatment (T1), and at the end of the treatment (T2).

RESULTS

Forty-four patients participated in this study (22 patients in each group). Participants in both groups showed improvements in mean arterial pressure (MAP) values, oxygenation indices, and urinary output, and decreased vasoactive-inotropic scores (VISs), heart rates, lactic acid levels, and serum creatinine levels after blood purification. Reductions in cytokine levels were observed at T1 in both groups. Improvement the haemodynamic status was higher in the oXiris group than in the ST group at T2 (MAP: 79.0 [76.0, 85.0] vs. 77.0 [72.75, 79.25] mm Hg, p = 0.04; VISs: 9.10 [0.00, 16.69] vs. 19.05 [10.60, 26.33], p = 0.03, respectively). Patients in the oXiris group also had lower cytokine levels than those in the ST group at T1 (tumour necrosis factor-α: 24.55 [16.9, 30.15] vs. 30.15 [23.38, 34.13] pg/mL, p = 0.04; interleukin (IL)-6: 66.63 [46.21, 102.20] vs. 125.48 [79.73, 167.97] pg/mL, p = 0.01; IL-8: 53.59 [35.10, 66.01] vs. 63.60 [45.58, 83.37] pg/mL, p = 0.04; IL-10: 13.50 [10.35, 18.68] vs. 17.15 [13.80, 21.95] pg/mL, p = 0.04, respectively). There were no significant differences between the 2 groups regarding hospital mortality, intensive care unit length of stay (LOS), and hospital LOS.

CONCLUSION

Blood purification using the AN69-oXiris or AN69-ST filter proved useful for septic patients, which was associated with reduced cytokine levels and improved clinical condition. Patients treated with AN69-oXiris had a more remarkable improvement in haemodynamic status and lower cytokine levels than those treated with AN69-ST filter, but there were no differences in clinical outcomes. Further investigations are needed to prove this finding.

Immune Modulation in Critically Ill Septic Patients

Sepsis is triggered by infection-induced immune alteration and may be theoretically improved by pharmacological and extracorporeal immune modulating therapies. Pharmacological immune modulation may have long lasting clinical effects, that may even worsen patient-related outcomes. On the other hand, extracorporeal immune modulation allows short-term removal of inflammatory mediators from the bloodstream. Although such therapies have been widely used in clinical practice, the role of immune modulation in critically ill septic patients remains unclear and little evidence supports the role of immune modulation in this clinical context. Accordingly, further research should be carried out by an evidence-based and personalized approach in order to improve the management of critically ill septic patients.

Endotoxin Adsorbent Therapy in Severe COVID-19 Pneumonia

INTRODUCTION

Uncontrolled systemic inflammation may occur in severe coronavirus disease 19 (COVID-19). We have previously shown that endotoxemia, presumably from the gut, may complicate COVID-19. However, the role of endotoxin adsorbent (EA) therapy to mitigate organ dysfunction in COVID-19 has not been explored.

METHODS

We conducted a retrospective observational study in COVID-19 patients who received EA therapy at the King Chulalongkorn Memorial Hospital, Bangkok, Thailand, between March 13 and April 17, 2020. Relevant clinical and laboratory data were collected by inpatient chart review.

RESULTS

Among 147 hospitalized COVID-19 patients, 6 patients received EA therapy. All of the 6 patients had severe COVID-19 infection with acute respiratory distress syndrome (ARDS). Among these, 5 of them were mechanically ventilated and 4 had complications of secondary bacterial infection. The endotoxin activity assay (EAA) results of pre-EA therapy ranged from 0.47 to 2.79. The choices of EA therapy were at the discretion of attending physicians. One patient was treated with oXiris® along with continuous renal replacement therapy, and the others received polymyxin B hemoperfusion sessions. All patients have survived and were finally free from the mechanical ventilation as well as had improvement in PaO2/FiO2 ratio and decreased EAA level after EA therapy.

CONCLUSIONS

We demonstrated the clinical improvement of severe COVID-19 patients with elevated EAA level upon receiving EA therapy. However, the benefit of EA therapy in COVID-19 ARDS is still unclear and needs to be elucidated with randomized controlled study.

Up-to-date information on polymyxin B-immobilized fiber column direct hemoperfusion for septic shock

Endotoxin adsorption therapy by polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) has been used for the treatment of septic shock patients. Endotoxin, an outer membrane component of Gram-negative bacteria, plays an important role in the pathogenesis of septic shock. Endotoxin triggers a signaling cascade for leukocytes, macrophage, and endothelial cells to secrete various mediators including cytokines and nitric oxide, leading to septic shock and multiple organ dysfunction syndrome. PMX-DHP directly adsorbed not only endotoxin but also monocytes and anandamide. It reduced blood levels of inflammatory cytokines such as interleukin (IL)-1, IL-6, tumor necrosis factor-alpha and IL-17A, adhesion molecules, plasminogen activator inhibitor 1, and high mobility group box-1. As a result, PMX-DHP increased blood pressure and reduced the dose of vasoactive-inotropic agents. PMX-DHP improved monocyte human leukocyte antigen-DR expression in patients with severe sepsis and septic shock. A post hoc analysis of EUPHRATES (Evaluating the Use of Polymyxin B Hemoperfusion in Randomized Controlled Trial of Adults Treated for Endotoxemia and Septic Shock) trial has shown that PMX-DHP significantly reduced 28-day mortality compared with the control group in septic shock patients with endotoxin activity assay level between 0.60 and 0.89. Longer duration of PMX-DHP may be another strategy to bring out the beneficial effects of PMX-DHP. Further studies are needed to confirm the efficacy of PMX-DHP treatment for septic shock.

Blood purification for sepsis: an overview

Sepsis is a life-threatening organ failure exacerbated by a maladaptive infection response from the host, and is one of the major causes of mortality in the intensive care unit. In recent decades, several extracorporeal blood purification techniques have been developed to manage sepsis by acting on both the infectious agents themselves and the host immune response. This research aims to summarize recent progress on extracorporeal blood purification technologies applied for sepsis, discuss unanswered questions on renal replacement therapy for septic patients, and present a decision-making strategy for practitioners.

Therapeutic Rationale for Endotoxin Removal with Polymyxin B Immobilized Fiber Column (PMX) for Septic Shock

Endotoxin removal therapy with polymyxin B immobilized fiber column (PMX) has been clinically applied for sepsis and septic shock patients since 1994. The effectiveness and usefulness of this therapy have been demonstrated for more than a quarter of a century. However, a documented survival benefit has not yet been demonstrable in a large, multicenter, randomized and controlled trial. Following the findings derived from a large sepsis clinical trial with PMX in North America, a new trial is ongoing to determine if PMX has a long-term survival benefit when administered to septic patients. Another approach to support a survival benefit from intervention with PMX is to utilize a detailed analysis available from a large clinical data base. The endotoxin adsorption capacity of PMX columns in vitro and the effectiveness of PMX columns can be further demonstrable in animal models. The capability of PMX and details of its mechanism of action to intervene in the sepsis cascade and impede organ dysfunction in septic patients is not fully understood. The surface antigen expression in monocytes and neutrophils are improved after PMX therapy. Immunomodulatory effects as a result of endotoxin removal and/or other mechanisms of action have been suggested. These effects and other potential immune effects may explain some of the improved effects upon organ dysfunction of sepsis and septic shock patients. Endotoxemia may be involved in the pathophysiology of other diseases than sepsis. A rapid diagnostic method to detect and target endotoxemia could allow us to practice precision medicine and expand the clinical indications of endotoxin removal therapy.

Uncertain Clinical Effect of Polymyxin B Hemoperfusion in Patients with Septic Acute Kidney Injury Requiring Continuous Renal Replacement Therapy

ABSTRACT

Polymyxin B hemoperfusion (PMX-HP) may improve the clinical outcomes of patients with sepsis and gram-negative bacteremia by reducing endotoxin levels. However, the recent studies with the variable degree of renal support have shown that the improvement of survival rate by PMX-HP remains unclear in such patients. Therefore, we investigated whether the addition of PMX-HP to continuous renal replacement therapy (CRRT) could improve the survival rate than CRRT alone. This study included 231 patients with sepsis undergoing CRRT alone or PMX-HP with CRRT. Primary outcomes were 28-day and 90-day all-cause mortality. Urine output, ventilator support, and Sequential Organ Failure Assessment (SOFA) score were not significantly different between the two groups. Crude 28-day and 90-day mortality rates were higher in the PMX-HP with CRRT group than in the CRRT alone group. To correct for disease severity, propensity score (PS) matching was performed with acute respiratory distress syndrome, mechanical ventilation support, extracorporeal membrane oxygenation, infection source (abdomen), age, inotropic score, SOFA score, C-reactive protein, and procalcitonin levels. Sixty-six PS-matched pairs revealed significantly higher 28-day and 90-day mortality rates in the PMX-HP with CRRT group than in the CRRT alone group. Considering the mortality rates after PS matching, the additional use of PMX-HP does not improve the clinical outcomes of patients with sepsis and acute kidney injury requiring CRRT.

Clearance of inflammatory cytokines in patients with septic acute kidney injury during renal replacement therapy using the EMiC2 filter (Clic-AKI study)

BACKGROUND

The EMiC2 membrane is a medium cut-off haemofilter (45 kiloDalton). Little is known regarding its efficacy in eliminating medium-sized cytokines in sepsis. This study aimed to explore the effects of continuous veno-venous haemodialysis (CVVHD) using the EMiC2 filter on cytokine clearance.

METHODS

This was a prospective observational study conducted in critically ill patients with sepsis and acute kidney injury requiring kidney replacement therapy. We measured concentrations of 12 cytokines [Interleukin (IL) IL-1β, IL-1α, IL-2, IL-4, IL-6, IL-8, IL-10, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, vascular endothelial growth factor, monocyte chemoattractant protein (MCP)-1, epidermal growth factor (EGF)] in plasma at baseline (T0) and pre- and post-dialyzer at 1, 6, 24, and 48 h after CVVHD initiation and in the effluent fluid at corresponding time points. Outcomes were the effluent and adsorptive clearance rates, mass balances, and changes in serial serum concentrations.

RESULTS

Twelve patients were included in the final analysis. All cytokines except EGF concentrations declined over 48 h (p < 0.001). The effluent clearance rates were variable and ranged from negligible values for IL-2, IFN-γ, IL-1α, IL-1β, and EGF, to 19.0 ml/min for TNF-α. Negative or minimal adsorption was observed. The effluent and adsorptive clearance rates remained steady over time. The percentage of cytokine removal was low for most cytokines throughout the 48-h period.

CONCLUSION

EMiC2-CVVHD achieved modest removal of most cytokines and demonstrated small to no adsorptive capacity despite a decline in plasma cytokine concentrations. This suggests that changes in plasma cytokine concentrations may not be solely influenced by extracorporeal removal.

TRIAL REGISTRATION

NCT03231748, registered on 27th July 2017.

Endotoxemia and circulating bacteriome in severe COVID-19 patients

BACKGROUND

When severe, COVID-19 shares many clinical features with bacterial sepsis. Yet, secondary bacterial infection is uncommon. However, as epithelium is injured and barrier function is lost, bacterial products entering the circulation might contribute to the pathophysiology of COVID-19.

METHODS

We studied 19 adults, severely ill patients with COVID-19 infection, who were admitted to King Chulalongkorn Memorial Hospital, Bangkok, Thailand, between 13th March and 17th April 2020. Blood samples on days 1, 3, and 7 of enrollment were analyzed for endotoxin activity assay (EAA), (1 → 3)-β-D-glucan (BG), and 16S rRNA gene sequencing to determine the circulating bacteriome.

RESULTS

Of the 19 patients, 13 were in intensive care and 10 patients received mechanical ventilation. We found 8 patients with high EAA (≥ 0.6) and about half of the patients had high serum BG levels which tended to be higher in later in the illness. Although only 1 patient had a positive blood culture, 18 of 19 patients were positive for 16S rRNA gene amplification. Proteobacteria was the most abundant phylum. The diversity of bacterial genera was decreased overtime.

CONCLUSIONS

Bacterial DNA and toxins were discovered in virtually all severely ill COVID-19 pneumonia patients. This raises a previously unrecognized concern for significant contribution of bacterial products in the pathogenesis of this disease.

Effect of Extracorporeal Blood Purification on Mortality in Sepsis: A Meta-Analysis and Trial Sequential Analysis

OBJECTIVE

The objective of this study was to conduct a meta-analysis and trial sequential analysis (TSA) of published randomized controlled trials (RCTs) to determine whether mortality benefit exists for extracorporeal blood purification techniques in sepsis.

DATA SOURCES

A systematic search on MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for RCTs was performed.

STUDY SELECTION

RCTs investigating the effect of extracorporeal blood purification device use on mortality among critically ill septic patients were selected.

DATA EXTRACTION

Mortality was assessed using Mantel-Haenszel models, and I2 was used for heterogeneity. Data are presented as odds ratios (OR); 95% confidence intervals (CIs); p values; I2. Using the control event mortality proportion, we performed a TSA and calculated the required information size using an anticipated intervention effect of a 14% relative reduction in mortality.

DATA SYNTHESIS

Thirty-nine RCTs were identified, with 2,729 patients. Fourteen studies used hemofiltration (n = 789), 17 used endotoxin adsorption devices (n = 1,363), 3 used nonspecific adsorption (n = 110), 2 were cytokine removal devices (n = 117), 2 used coupled plasma filtration adsorption (CPFA) (n = 207), 2 combined hemofiltration and perfusion (n = 40), and 1 used plasma exchange (n = 106). On conventional meta-analysis, hemofiltration (OR 0.56 [0.40-0.79]; p < 0.001; I2 = 0%), endotoxin removal devices (OR 0.40 [0.23-0.67], p < 0.001; I2 = 71%), and nonspecific adsorption devices (OR 0.32 [0.13-0.82]; p = 0.02; I2 = 23%) were associated with mortality benefit, but not cytokine removal (OR 0.99 [0.07-13.42], p = 0.99; I2 = 64%), CPFA (OR 0.50 [0.10-2.47]; p = 0.40; I2 = 64%), or combined hemofiltration and adsorption (OR 0.71 [0.13-3.79]; p = 0.69; I2 = 0%). TSA however revealed that based on the number of existing patients recruited for RCTs, neither hemofiltration (TSA-adjusted CI 0.29-1.10), endotoxin removal devices (CI 0.05-3.40), nor nonspecific adsorption devices (CI 0.01-14.31) were associated with mortality benefit.

CONCLUSION

There are inadequate data at present to conclude that the use of extracorporeal blood purification techniques in sepsis is beneficial. Further adequately powered RCTs are required to confirm any potential mortality benefit, which may be most evident in patients at greatest risk of death.

Effectiveness of polymyxin B-immobilized hemoperfusion against sepsis and septic shock: A systematic review and meta-analysis

PURPOSE

To evaluate the efficacy and safety of Polymyxin B-immobilized hemoperfusion (PMX-HP) against sepsis or septic shock.

METHODS

We searched databases (PubMed, EMBASE and Cochrane Library) to identify eligible randomized controlled trials (RCTs). The primary outcomes we included in this review were mortality at the longest follow-up available and serious adverse events associated with treatments. We used the Cochrane risk of bias assessment tool to evaluate risk of bias. Trial Sequential Analysis (TSA) was performed to assess the conclusion reached in our research.

RESULTS

Thirteen studies including 1163 patients were identified. Use of PMX-HP could reduce overall mortality [relative risk (RR) 0.68, 95% confidence interval (CI) 0.51-0.91, P = 0.01]. An interesting finding was that the mortality of patients in Acute Physiology and Chronic Health Evaluation (APACHE II) scores <25 group (RR 0.64, 95% CI 0.52-0.78, P < 0.0001) and sepsis group (RR 0.48, 95% CI 0.32-0.72, P = 0.0003) significantly decreased after PMX-HP treatment. The result also showed that PMX-HP could reduce endotoxin levels [Standardized mean difference (SMD) -1.53, 95% CI -2.92- -0.13, P = 0.03] and improve mean arterial pressure (SMD 1.07, 95% CI 0.14-2.01, P = 0.02). Serious adverse events between the PMX-HP group and standard therapy group were not significantly different (RR 2.16, 95% CI 0.97-4.80, I² = 0%, P = 0.06). However, TSA did not provide conclusive evidence and more high quality RCTs were required.

CONCLUSION

Using PMX-HP to treat patients with less severe sepsis can reduce overall mortality and is safe. Treatment efficacy may benefit from the reduction of endotoxin level and the improvement of hemodynamics. More high quality RCTs are required to further evaluate the clinical role of PMX-HP against severe sepsis or septic shock.

Treatment of Pyonephritis Complicated by Septic Shock Using Extracorporeal Device Polymyxin B-Hemoperfusion

Direct hemoperfusion using polymyxin B-immobilized fiber (PMX-DHP) is an established treatment method for septic shock caused by Gram-negative infections. We report one instance in which PMX-DHP therapy has been used successfully in a 33-year-old woman with septic shock from urosepsis. Although there is lack of recommendations in latest Surviving Sepsis Campaign Guidelines, evidence of PMX-DHP efficacy in this subset of patients is growing.

Blood Purification Techniques for Sepsis and Septic AKI

Sepsis is the primary cause of acute kidney injury in critically ill patients. During the past decades, several extracorporeal blood purification techniques have been developed for sepsis and sepsis-induced acute kidney injury management. These therapies could act on both the infectious agent itself and the host immune response. In this article, we review the available literature discussing the different extracorporeal blood purification techniques, including high-volume hemofiltration, cascade hemofiltration, hemoperfusion, coupled plasma filtration adsorption, plasma exchange, and specific optimized renal replacement therapy membranes.

Beneficial effect modification on survival outcome of sepsis between ART-123 and polymyxin B‑immobilised haemoperfusion: a nationwide Japanese registry study

Background

Although recently published randomised controlled trials did not confirm significant positive effect of ART-123 or polymyxin B‑immobilised haemoperfusion (PMX-HP) on survival outcome, previous studies using a dataset of 3195 patients with sepsis registered at 42 intensive care units throughout Japan revealed significantly reduced mortality following these treatments. A study has suggested the efficacy of combination therapy with ART-123 and PMX-HP; however, it did not evaluate the effect modification between them. We hypothesised that coadministration of ART-123 and PMX-HP has a significant positive effect modification on survival outcome. The purpose of this study was to evaluate the effect modification between ART-123 and PMX-HP treatment on the survival outcome of sepsis using post hoc analysis of the dataset of the Japan Septic Disseminated Intravascular Coagulation registry.

Results

Of the 3195 patients recorded in the registry, 2350 were analysed. The product term between ART-123 and PMX-HP was analysed by the Cox regression model to evaluate significance. The primary outcome of this study was hospital mortality. Although the administration of ART-123 was independently positively associated with survival outcome (adjusted hazard ratio [HR]: 0.834, 95% confidence interval [CI] 0.695–0.999; P = 0.049) in the model prior to the introduction of the product term, a significant effect modification on survival outcome was observed between the administration of ART-123 and PMX-HP treatment (adjusted HR: 0.667, 95% CI 0.462–0.961; P = 0.030).

Conclusions

The main effect of the administration of ART-123 may be beneficial for survival outcome in patients with sepsis. In addition, a significant beneficial effect modification on survival outcome was observed between the administration of ART-123 and PMX-HP treatment.

The haemodynamic effects of oXiris haemofilter in septic shock patients requiring renal support: A single-centre experience

Excessive pro-inflammatory and anti-inflammatory cytokines are mediators for haemodynamic alterations, metabolic acidosis, and multi-organ failure in sepsis. Recently, oXiris^® haemofilter (Baxter, IL, USA) has been introduced as a novel haemofilter to mitigate inflammatory response during sepsis-associated acute kidney injury requiring renal replacement therapy. In the present case series, the researchers retrospectively reviewed critically ill patients with septic shock with the use of at least one oXiris haemofilter during continuous renal replacement therapy between June 2015 and December 2017. The timing for oXiris initiation was at the nephrologists' discretion. The impact of oXiris haemofilter was evaluated on mean arterial pressure, vasopressor dosage, Sequential Organ Failure Assessment score, lactate and base excess during 72 h after treatment. Thirty-five patients were enrolled in the study. An improvement of haemodynamic status was found, shown by increased mean arterial pressure by 6.1% (p = 0.35), decreased norepinephrine dose by 45.9% (p = 0.02), inotropic score by 26.4% (p = 0.02) and vasopressor dependency index by 40.5% (p = 0.01). Cardiovascular Sequential Organ Failure Assessment scores significantly decreased over 72 h (p = 0.02). Blood lactate levels and base excess also showed statistically significant improvements. The median filter lifetime was 23 (interquartile range = 14-36) hours. The intensive care unit mortality was 82.9%. Treatment with oXiris was safe and well-tolerated with no device-related adverse events. In conclusion, continuous renal replacement therapy with oXiris haemofilter is safe and may improve haemodynamic parameters in septic patients with severe renal dysfunction. Nonetheless, these findings were drawn from a retrospective analysis without a control group, and therefore cannot be generalised. Randomised controlled trials are warranted to confirm these findings.

Blood Purification and Mortality in Sepsis and Septic Shock: A Systematic Review and Meta-analysis of Randomized Trials

BACKGROUND

Sepsis and septic shock are severe inflammatory conditions related to high morbidity and mortality. We performed a systematic review with meta-analysis of randomized trials to assess whether extracorporeal blood purification reduces mortality in this setting.

METHODS

Electronic databases were searched for pertinent studies up to January 2019. We included randomized controlled trials on the use of hemoperfusion, hemofiltration without a renal replacement purpose, and plasmapheresis as a blood purification technique in comparison to conventional therapy in adult patients with sepsis and septic shock. The primary outcome was mortality at the longest follow-up available. We calculated relative risks and 95% CIs. The grading of recommendations assessment, development and evaluation methodology for the certainty of evidence was used.

RESULTS

Thirty-seven trials with 2,499 patients were included in the meta-analysis. Hemoperfusion was associated with lower mortality compared to conventional therapy (relative risk = 0.88 [95% CI, 0.78 to 0.98], P = 0.02, very low certainty evidence). Low risk of bias trials on polymyxin B immobilized filter hemoperfusion showed no mortality difference versus control (relative risk = 1.14 [95% CI, 0.96 to 1.36], P = 0.12, moderate certainty evidence), while recent trials found an increased mortality (relative risk = 1.22 [95% CI, 1.03 to 1.45], P = 0.02, low certainty evidence); trials performed in the United States and Europe had no significant difference in mortality (relative risk = 1.13 [95% CI, 0.96 to 1.34], P = 0.15), while trials performed in Asia had a positive treatment effect (relative risk = 0.57 [95% CI, 0.47 to 0.69], P < 0.001). Hemofiltration (relative risk = 0.79 [95% CI, 0.63 to 1.00], P = 0.05, very low certainty evidence) and plasmapheresis (relative risk = 0.63 [95% CI, 0.42 to 0.96], P = 0.03, very low certainty evidence) were associated with a lower mortality.

CONCLUSIONS

Very low-quality randomized evidence demonstrates that the use of hemoperfusion, hemofiltration, or plasmapheresis may reduce mortality in sepsis or septic shock. Existing evidence of moderate quality and certainty does not provide any support for a difference in mortality using polymyxin B hemoperfusion. Further high-quality randomized trials are needed before systematic implementation of these therapies in clinical practice.

The role of neutrophil chemotaxis activity as an immunologic biomarker to predict mortality in critically-ill patients with severe sepsis

BACKGROUND

Innate immunity is an important host response to infection. However, the role of innate immunity as a prognostic biomarker in severe sepsis is still unknown. This study is to evaluate the discriminatory characteristics of these biomarkers on clinical outcome.

MATERIALS AND METHODS

Retrospective study was conducted in critically ill patients with severe sepsis. Neutrophil function was assessed by neutrophil chemotaxis activity and CD-11b expression. Monocyte function was assessed by measurement of mHLA-DR expression and presepsin level. The primary end point was 28 day-mortality.

RESULTS

A total of 136 participants were enrolled. Patients were classified into 2 groups as survivors (n = 63, 46.3%) and non-survivors (n = 73, 53.7%). Neutrophil chemotaxis activity was significantly higher in survivors (46.7% vs. 41.2%, p = .023). There was no difference in the remaining biomarker levels between survivors and non-survivors. Only decreased neutrophil chemotaxis activity was associated with 28-day mortality. Combining neutrophil chemotaxis activity with mHLA-DR, CD-11b expression, presepsin, and SOFA score provided the highest AUC of 0.90 (0.84-0.96) in predicting 28-day mortality.

CONCLUSION

Neutrophil chemotaxis activity appears to be a promising novel immunologic biomarker in predicting clinical outcome in patients with severe sepsis.

Acute kidney injury from sepsis: current concepts, epidemiology, pathophysiology, prevention and treatment

Sepsis-associated acute kidney injury (S-AKI) is a frequent complication of the critically ill patient and is associated with unacceptable morbidity and mortality. Prevention of S-AKI is difficult because by the time patients seek medical attention, most have already developed acute kidney injury. Thus, early recognition is crucial to provide supportive treatment and limit further insults. Current diagnostic criteria for acute kidney injury has limited early detection; however, novel biomarkers of kidney stress and damage have been recently validated for risk prediction and early diagnosis of acute kidney injury in the setting of sepsis. Recent evidence shows that microvascular dysfunction, inflammation, and metabolic reprogramming are 3 fundamental mechanisms that may play a role in the development of S-AKI. However, more mechanistic studies are needed to better understand the convoluted pathophysiology of S-AKI and to translate these findings into potential treatment strategies and add to the promising pharmacologic approaches being developed and tested in clinical trials.

The effect of direct hemoperfusion with polymyxin B immobilized cartridge on meropenem in critically ill patients requiring renal support

PURPOSE

To evaluate the effect of direct hemoperfusion with polymyxin B immobilized cartridge (DHP-PMX) on meropenem pharmacokinetics in critically ill patients with sepsis requiring continuous venovenous hemofiltration (CVVH).

MATERIAL AND METHODS

After intravenous infusion of 1 g meropenem over 3 h repeated every 8 h for at least 3 doses, 2 serial blood and ultrafiltration fluid samples were collected: one over a dose interval of meropenem with DHP-PMX therapy; and the other on the following day over a dose interval of meropenem with no DHP-PMX therapy. Meropenem concentrations were measured by high performance liquid chromatography. Pharmacokinetic parameters of meropenem and extraction ratio of DHP-PMX were calculated.

RESULTS

Mean AUC_0-8 of meropenem on DHP-PMX day was comparable to that of the DHP-PMX free day (285.2 ± 138.2 vs 297.8 ± 130.2 mg ∗ h/L; paired t-test, p = .618). No statistical significance of peak and trough concentrations, volume of distribution, sieving coefficient, or half-life were found. Extraction ratio of DHP-PMX on meropenem was 0 [0-0.03] and clearance by DHP-PMX was 0.04 [0-0.2] L/h which was not considered clinically significant.

CONCLUSIONS

No significant effect of DHP-PMX on meropenem pharmacokinetics was observed among severe sepsis/septic shock patients during CVVH treatment.

TRIAL REGISTRATION

Clinical Trial Registry detail: NCT registry: 02413541 (First registered March 3, 2015, last update October 16, 2017).

Polymyxin B hemoperfusion in endotoxemic septic shock patients without extreme endotoxemia: a post hoc analysis of the EUPHRATES trial

PURPOSE

The EUPHRATES trial examined the impact of polymyxin B hemoperfusion (PMX) on mortality in patients with septic shock and endotoxemia, defined as EAA ≥ 0.60. No difference was found in 28-day all-cause mortality. However, the trial showed that in some patients with septic shock the burden of endotoxin activity was extreme (EAA ≥ 0.9). In a post hoc analysis, we evaluated the impact of PMX use in patients with septic shock and endotoxin activity measured between 0.6-0.89.

METHODS

Post-hoc analysis of the EUPHRATES trial for the 194 patients with EAA ≥ 0.6-0.89 who completed two treatments (PMX or sham). The primary end point was mortality at 28 days adjusted for APACHE II score and baseline mean arterial pressure (MAP). Additional end points included changes in MAP, cumulative vasopressor index (CVI), median EAA reduction, ventilator-free days (VFD), dialysis-free days (DFD) and hospital length of stay. Subpopulations analyzed were site and type of infection and those with norepinephrine dose > 0.1 mcg/kg/min at baseline.

RESULTS

At 28 days, 23 patients of 88 (26.1%) in the PMX group died versus 39 of 106 (36.8%) in the sham group [risk difference 10.7%, OR 0.52, 95% CI (0.27, 0.99), P = 0.047]. When unadjusted for baseline variables, P = 0.11. The 28-day survival time in the PMX group was longer than for the sham group [HR 0.56 (95% CI 0.33, 0.95) P = 0.03]. PMX treatment compared with sham showed greater change in MAP [median (IQR) 8 mmHg (- 0.5, 19.5) vs. 4 mmHg (- 4.0, 11) P = 0.04] and VFD [median (IQR) 20 days (0.5, 23.5) vs. 6 days (0, 20), P = 0.004]. There were no significant differences in other end points. There was a significant difference in mortality in PMX-treated patients with no bacterial growth on culture [PMX, 6/30 (20%) vs. sham, 13/31 (41.9%), P = 0.005]. The median EAA change in the population was - 12.9% (range: increase 49.2%-reduction 86.3%). The mortality in the above median EAA change group was PMX: 6/38 (15.7%) vs. sham 15/49 (30.6%), P = 0.08.

CONCLUSIONS

These hypothesis-generating results, based on an exploratory post hoc analysis of the EUPHRATES trial, suggest measurable responses in patients with septic shock and an EAA ≥ 0.6 to 0.89 on changes in mean arterial pressure, ventilator-free days and mortality.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT01046669. Funding Spectral Medical Incorporated.