A rapid assay of endotoxin in whole blood using autologous neutrophil dependent chemiluminescence

Challenges in Septic Shock: From New Hemodynamics to Blood Purification Therapies

Sepsis and septic shock are associated with high mortality, with diagnosis and treatment remaining a challenge for clinicians. Their management classically encompasses hemodynamic resuscitation, antibiotic treatment, life support, and focus control; however, there are aspects that have changed. This narrative review highlights current and avant-garde methods of handling patients experiencing septic shock based on the experience of its authors and the best available evidence in a context of uncertainty. Following the first recommendation of the Surviving Sepsis Campaign guidelines, it is recommended that specific sepsis care performance improvement programs are implemented in hospitals, i.e., "Sepsis Code" programs, designed ad hoc, to achieve this goal. Regarding hemodynamics, the importance of perfusion and hemodynamic coherence stand out, which allow for the recognition of different phenotypes, determination of the ideal time for commencing vasopressor treatment, and the appropriate fluid therapy dosage. At present, this is not only important for the initial timing, but also for de-resuscitation, which involves the early weaning of support therapies, directed elimination of fluids, and fluid tolerance concept. Finally, regarding blood purification therapies, those aimed at eliminating endotoxins and cytokines are attractive in the early management of patients in septic shock.

Effects of enhanced adsorption haemofiltration versus haemoadsorption in severe, refractory septic shock with high levels of endotoxemia: the ENDoX bicentric, randomized, controlled trial

BACKGROUND

Endotoxin adsorption is a promising but controversial therapy in severe, refractory septic shock and conflicting results exist on the effective capacity of available devices to reduce circulating endotoxin and inflammatory cytokine levels.

METHODS

Multiarm, randomized, controlled trial in two Swiss intensive care units, with a 1:1:1 randomization of patients suffering severe, refractory septic shock with high levels of endotoxemia, defined as an endotoxin activity ≥ 0.6, a vasopressor dependency index ≥ 3, volume resuscitation of at least 30 ml/kg/24 h and at least single organ failure, to a haemoadsorption (Toraymyxin), an enhanced adsorption haemofiltration (oXiris) or a control intervention. Primary endpoint was the difference in endotoxin activity at 72-h post-intervention to baseline. In addition, inflammatory cytokine, vasopressor dependency index and SOFA-Score dynamics over the initial 72 h were assessed inter alia.

RESULTS

In the 30, out of 437 screened, randomized patients (10 Standard of care, 10 oXiris, 10 Toraymyxin), endotoxin reduction at 72-h post-intervention-start did not differ among interventions (Standard of Care: 12 [1-42]%, oXiris: 21 [10-51]%, Toraymyxin: 23 [10-36]%, p = 0.82). Furthermore, no difference between groups could be observed neither for reduction of inflammatory cytokine levels (p = 0.58), nor for vasopressor weaning (p = 0.95) or reversal of organ injury (p = 0.22).

CONCLUSIONS

In a highly endotoxemic, severe, refractory septic shock population neither the Toraymyxin adsorber nor the oXiris membrane could show a reduction in circulating endotoxin or cytokine levels over standard of care. Trial registration ClinicalTrials.gov. NCT01948778. Registered August 30, 2013. https://clinicaltrials.gov/study/NCT01948778.

Clinical implications of endotoxin activity and Polymyxin-B hemoperfusion in critically ill patients with septic cardiomyopathy: A single-center, retrospective, observational study

BACKGROUND

To explore the association between endotoxin activity (EA) and septic cardiomyopathy (SCM), the relationship between endotoxin removal by Polymyxin-B hemoperfusion (PMX-HP) and recovery from SCM (R-SCM), and the correlation between R-SCM and the 28-day mortality in septic patients admitted to the intensive care unit (ICU).

METHODS

Observational study that included patients admitted to two ICUs of a tertiary university hospital between April 2011 and December 2019, who received PMX-HP for sepsis/septic shock. The SCM and R-SCM were assessed by transthoracic echocardiography.

RESULTS

Among 148 patients, SCM was diagnosed in 60 (46%) of them and had no relationship with median EA (SCM group: 0.73; no-SCM group: 0.66, p = 0.48). Recovery from SCM was observed in 24 patients (49%) and was independently associated with the PMX-HP (OR 4.19, 95%CI [1.22, 14.3]; p = 0.02) and the SAPS2 II score (OR 0.94, 95%CI [0.9, 0.98]; p = 0.006). In the SCM group, the 28-day mortality was 60% and was independently predicted by R-SCM (OR 0.02, 95%CI [0.001, 0.3] p = 0.005) and SAPS II score (OR 1.11, 95%CI [1.01, 1.23] p = 0.037).

CONCLUSIONS

In septic patients, EA was not associated with SCM. However, endotoxin removal by Polymyxin-B hemoperfusion was associated with recovery from cardiomyopathy, which was a predictor of lower 28-day mortality.

Endotoxic Septic Shock: Diagnosis and Treatment

Endotoxin, also referred to as lipopolysaccharide (LPS), is a potent stimulator of the inflammatory cascade which may progress to sepsis and septic shock. The term endotoxic septic shock has been used for patients who have a clinical phenotype that is characterized by high endotoxin activity in addition to a high burden of organ failure; especially a pattern of organ failure including hepatic dysfunction, acute kidney injury, and various forms of endothelial dysfunction. Endotoxic septic shock has been a target for drug therapy for decades with no success. A likely barrier to their success was the inability to quantify endotoxin in the bloodstream. The Endotoxin Activity Assay (EAA) is positioned to change this landscape. In addition, medical devices using adsorptive technology in an extra-corporeal circulation has been shown to remove large quantities of endotoxin from the bloodstream. Focusing on the use of EAA to determine high concentrations of endotoxin will allow patients with endotoxic septic shock to be identified quickly and these patients may benefit most from removal of endotoxin using extracorporeal methods.

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.

The Cytotoxic Effect of Septic Plasma on Healthy RBCs: Is Eryptosis a New Mechanism for Sepsis?

Sepsis is a life-threatening multiple-organ dysfunction induced by infection and is one of the leading causes of mortality and critical illness worldwide. The pathogenesis of sepsis involves the alteration of several biochemical pathways such as immune response, coagulation, dysfunction of endothelium and tissue damage through cellular death and/or apoptosis. Recently, in vitro and in vivo studies reported changes in the morphology and in the shape of human red blood cells (RBCs) causing erythrocyte death (eryptosis) during sepsis. Characteristics of eryptosis include cell shrinkage, membrane blebbing, and surface exposure to phosphatidylserine (PS), which attract macrophages. The aim of this study was to evaluate the in vitro induction of eryptosis on healthy RBCs exposed to septic plasma at different time points. Furthermore, we preliminary investigated the in vivo levels of eryptosis in septic patients and its relationship with Endotoxin Activity Assay (EAA), mortality and other biological markers of inflammation and oxidative stress. We enrolled 16 septic patients and 16 healthy subjects (no systemic inflammation in the last 3 months) as a control group. At diagnosis, we measured Interleukin-6 (IL-6) and Myeloperoxidase (MPO). For in vitro study, healthy RBCs were exposed to the plasma of septic patients and CTR for 15 min, 1, 2, 4 and 24 h. Morphological markers of death and eryptosis were evaluated by flow cytometric analyses. The cytotoxic effect of septic plasma on RBCs was studied in vitro at 15 min, 1, 2, 4 and 24 h. Healthy RBCs incubated with plasma from septic patients went through significant morphological changes and eryptosis compared to those exposed to plasma from the control group at all time points (all, p < 0.001). IL-6 and MPO levels were significantly higher in septic patients than in controls (both, p < 0.001). The percentage of AnnexinV-binding RBCs was significantly higher in septic patients with EAA level ≥0.60 (positive EAA: 32.4%, IQR 27.6-36.2) compared to septic patients with EAA level <0.60 (negative EAA: 14.7%, IQR 5.7-30.7) (p = 0.04). Significant correlations were observed between eryptosis and EAA levels (Spearman rho2 = 0.50, p < 0.05), IL-6 (Spearman rho2 = 0.61, p < 0.05) and MPO (Spearman rho2 = 0.70, p < 0.05). In conclusion, we observed a quick and great cytotoxic effect of septic plasma on healthy RBCs and a strong correlation with other biomarkers of severity of sepsis. Based on these results, we confirmed the pathological role of eryptosis in sepsis and we hypothesized its use as a biomarker of sepsis, potentially helping physicians to face important treatment decisions.

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.

Increased Endotoxin Activity in COVID-19 Patients Admitted to the Intensive Care Unit

OBJECTIVE

Endotoxin is a component of Gram-negative bacteria and can be measured in blood using the endotoxin activity assay (EAA). Endotoxin exposure initiates an inflammatory cascade that may contribute to organ dysfunction. Endotoxemia has been reported in previous viral pandemics and we investigated the extent of endotoxemia and its relationship to outcomes in critically ill patients with COVID-19.

MATERIALS AND METHODS

We conducted a Prospective Cohort Study of 96 critically-ill COVID-19 patients admitted to the George Washington University Hospital ICU from 25 Mar-6 Jun 2020. EAA and inflammatory markers (ferritin, d dimer, IL-6, CRP) were measured on ICU admission and at the discretion of the clinical team. Clinical outcomes (mortality, LOS, need for renal replacement therapy (RRT), intubation) were measured. Statistical analysis was conducted using descriptive statistics and effect estimates with 95% confidence intervals. Comparisons were made using chi-square tests for categorical variables, and T-tests for continuous variables.

RESULTS

A majority of patients (68.8%) had high EAA [≥ 0.60], levels seen in septic shock. Only 3 patients had positive bacterial cultures. EAA levels did not correlate with mortality, higher levels were associated with greater organ failure (cardiovascular, renal) and longer ICU LOS. Among 14 patients receiving RRT for severe AKI, one had EAA < 0.6 (p = 0.043). EAA levels did not directly correlate with other inflammatory markers.

CONCLUSIONS

High levels of endotoxin activity were found in a majority of critically-ill COVID-19 patients admitted to the ICU and were associated with greater risk for cardiovascular and renal failure. Further investigation is needed to determine if endotoxin reducing strategies are useful in treating severe COVID-19 infection.

Blood purification in sepsis and COVID-19: what´s new in cytokine and endotoxin hemoadsorption

Sepsis and COVID-19 are two clinical conditions that can lead to a dysregulated inflammatory state causing multiorgan dysfunction, hypercytokinemia, and a high risk of death. Specific subgroups of critically ill patients with particular characteristics could benefit from rescue treatment with hemoadsorption. There is a lack of adequately designed randomized controlled trials evaluating the potential benefits of cytokine or endotoxin hemoadsorption. Critically ill COVID-19 patients with severe acute respiratory failure poorly responsive to conventional treatment could be candidates to receive cytokine hemoadsorption in the presence of high levels of interleukin 6. This treatment can also be suitable for patients with refractory septic shock and hypercytokinemia. In the context of high endotoxin activity, hemoadsorption with polymyxin B could improve clinical parameters and the prognosis of patients with refractory septic shock. Predictive enrichment, using biomarkers or other individual features, identifies potential responders to cytokine, endotoxin, or sequential hemoadsorption. Besides, recognizing the particular subsets of patients likely to respond to one or both types of hemoadsorption will aid the design of future studies that accurately validate the effectiveness of these therapies.

Periodontitis and cardiometabolic disorders: The role of lipopolysaccharide and endotoxemia

Lipopolysaccharide is a virulence factor of gram-negative bacteria with a crucial importance to the bacterial surface integrity. From the host's perspective, lipopolysaccharide plays a role in both local and systemic inflammation, activates both innate and adaptive immunity, and can trigger inflammation either directly (as a microbe-associated molecular pattern) or indirectly (by inducing the generation of nonmicrobial, danger-associated molecular patterns). Translocation of lipopolysaccharide into the circulation causes endotoxemia, which is typically measured as the biological activity of lipopolysaccharide to induce coagulation of an aqueous extract of blood cells of the assay. Apparently healthy subjects have a low circulating lipopolysaccharide activity, since it is neutralized and cleared rapidly. However, chronic endotoxemia is involved in the pathogenesis of many inflammation-driven conditions, especially cardiometabolic disorders. These include atherosclerotic cardiovascular diseases, obesity, liver diseases, diabetes, and metabolic syndrome, where endotoxemia has been recognized as a risk factor. The main source of endotoxemia is thought to be the gut microbiota. However, the oral dysbiosis in periodontitis, which is typically enriched with gram-negative bacterial species, may also contribute to endotoxemia. As endotoxemia is associated with an increased risk of cardiometabolic disorders, lipopolysaccharide could be considered as a molecular link between periodontal microbiota and cardiometabolic diseases.

Precision medicine in sepsis and septic shock: From omics to clinical tools

Sepsis is a heterogeneous disease with variable clinical course and several clinical phenotypes. As it is associated with an increased risk of death, patients with this condition are candidates for receipt of a very well-structured and protocolized treatment. All patients should receive the fundamental pillars of sepsis management, which are infection control, initial resuscitation, and multiorgan support. However, specific subgroups of patients may benefit from a personalized approach with interventions targeted towards specific pathophysiological mechanisms. Herein, we will review the framework for identifying subpopulations of patients with sepsis, septic shock, and multiorgan dysfunction who may benefit from specific therapies. Some of these approaches are still in the early stages of research, while others are already in routine use in clinical practice, but together will help in the effective generation and safe implementation of precision medicine in sepsis.

Comparison of Endotoxin Activity Assay and Various Biomarkers for Severity Assessment in Colorectal Perforation Patients

Colorectal perforation is a serious disease with high mortality requiring emergency surgery. This study aimed to evaluate the role of the endotoxin activity assay (EAA) to assess the severity in patients admitted to the intensive care unit after emergency surgeries for colorectal perforations. Patients were divided into high (EAA ≥.4) and low (EAA <.4) groups based on the EAA levels, and the correlation between the EAA values and clinical variables related to the severity was evaluated. The SOFA scores were significantly higher in the high group than those in the low group. The high EAA value persisted even after 48 hours and extended the ICU length of stay. These results suggest that EAA may be a potential biomarker to assess severity and useful as one of the instrumental in predicting the outcomes for colorectal perforation patients.

Endotoxin Activity in Patients With Extracorporeal Membrane Oxygenation Life Support: An Observational Pilot Study

Background: Extracorporeal membrane oxygenation (ECMO) life support has become an integral part of intensive care. The endotoxin activity assay (EAA) is a useful test to measure endotoxemia severity in whole blood. To date, no information is available regarding the EAA levels and their effect on clinical outcomes in critically ill patients with ECMO support.

Methods: This prospective observational pilot study enrolled adult critically ill patients with ECMO support from August 2019 to December 2020. The EAA levels were measured within 24 h (T1), and at 25–48 (T2), 49–72 (T3), and 73–96 h (T4) after ECMO initiation. This study primarily aimed to investigate the incidence of high EAA levels (≥0.6) at each time point. Subsequent exploratory analyses were conducted to compare the EAA levels of venoarterial ECMO (VA-ECMO) patients between 30-day survivors and non-survivors. Post-hoc analysis was performed to compare the clinical outcomes of VA-ECMO patients with elevated EAA levels at T3 (vs. T1) and those without elevated EAA levels.

Results: A total of 39 VA-ECMO patients and 15 venovenous ECMO (VV-ECMO) patients were enrolled. At T1, the incidence of high EAA level (≥0.6) was 42% in VV-ECMO patients and 9% in VA-ECMO patients (P = 0.02). At T2, the incidence of high EAA level was 40% in VV-ECMO patients and 5% in VA-ECMO patients (P = 0.005). In VA-ECMO patients, EAA levels at T3 were significantly higher in 30-day non-survivors than in survivors (median [interquartile range]: 0.49 [0.37–0.93] vs. 0.31 [0.19–0.51], median difference 0.16 [95% confidence interval [CI], 0.02–0.31]; P = 0.024). Moreover, VA-ECMO patients with elevated EAA levels at T3 (vs. T1) had lower 30-day survival than patients without elevated EAA levels (39 vs. 83%, P = 0.026) and fewer ECMO free days by day 30 (median: 3 vs. 23 days, median difference 12 days [95% CI, 0–22]; P = 0.028).

Conclusions: A certain proportion of patients experienced high EAA levels (≥0.6) after VV-ECMO or VA-ECMO initiation. VA-ECMO patients with an elevated EAA level at 49–72 h were associated with poor clinical outcomes.

Impact of polymyxin B hemoperfusion therapy on high endotoxin activity level patients after successful infection source control: a prospective cohort study

We sought to evaluate the clinical implication of endotoxin levels in gram-negative bacilli (GNB)-induced abdominal septic shock patients with polymyxin B-hemoperfusion (PMX-HP) treatment. A prospective cohort of 60 patients who received surgical infectious source control for abdominal sepsis from January 2019 to December 2020 was included in the study. Endotoxin activity (EA) levels and Sequential Organ Failure Assessment (SOFA) scores were assessed immediately after surgery (baseline), 24, and 48 h post baseline. With receiver operating characteristic curves, the patients were stratified into two groups by the EA cut-off value (high-risk group vs low-risk group) and the clinical outcomes were compared. Logistic regression was performed to identify the clinical impact of PMX-HP on in-hospital death. Among the 31 high-risk patients (EA level ≥ 0.54), 16 patients (51.6%) received PMX-HP treatment and showed significant decreases in EA levels compared to patients who underwent conventional treatment only (− 0.34 vs − 0.12, p = 0.01). SOFA scores also showed significant improvement with PMX-HP treatment (12.8–8.9, p = 0.007). Fourteen in-hospital deaths occurred (45.2%), and PMX-HP treatment had a protective effect on in-hospital death (odds ratio (OR) 0.04, p = 0.03). In 29 low-risk patients (EA level < 0.54), seven patients (24.1%) received PMX-HP treatment and showed significant decreases in EA levels (0.46–0.16, p = 0.018). However, SOFA scores and in-hospital deaths were not improved by PMX-HP treatment. EA level significantly decreased after PMX-HP treatment and it may represent a therapeutic option to improve organ impairment and in-hospital death in septic shock patients with EA levels exceeding 0.54.

Leaky Gut Syndrome Is Associated with Endotoxemia and Serum (1→3)-β-D-Glucan in Severe Dengue Infection

The hallmark of severe dengue infection is the increased vascular permeability and hemodynamic alteration that might be associated with an intestinal permeability defect. However, the mechanisms underlying the gastrointestinal-related symptoms of dengue are not well characterized. A prospective observational study was conducted on patients with dengue who were categorized according to: (i) febrile versus critical phase and (ii) hospitalized patients with versus without the warning signs to evaluate the gut barrier using lactulose-to-mannitol excretion ratio (LEMR). Serum endotoxins, (1→3)-β-D-glucan (BG), and inflammatory parameters were measured. A total of 48 and 38 patients were enrolled in febrile illness and critical phase, respectively, while 22 and 64 patients presented with or without the warning signs, respectively. At enrollment, a positive LEMR test was found in 20 patients (91%) with warning signs, regardless of phase of infection. Likewise, serum endotoxins and BG, the indirect biomarkers for leaky gut, prominently increased in patients who developed severe dengue when compared with the non-severe dengue (endotoxins, 399.1 versus 143.4 pg/mL (p < 0.0001); BG, 123 versus 73.8 pg/mL (p = 0.016)). Modest impaired intestinal permeability occurred in dengue patients, particularly those with warning signs, and were associated with endotoxemia and elevated BG. Thus, leaky gut syndrome might be associated with severity of dengue infection.

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.

Polymyxin B hemoperfusion in coronavirus disease 2019 patients with endotoxic shock: Case series from EUPHAS2 registry

The coronavirus disease 2019 (COVID-19) has been shown to involve the gastrointestinal tract, which implies bacterial translocation and endotoxemia. The aim of this study was to evaluate the role of extracorporeal endotoxin removal by Polymyxin B hemoperfusion (PMX-HP), in the treatment of patients with COVID-19 and secondary bacterial infection. We conducted a subgroup analysis of a multicenter, multinational, prospective, and observational web-based database (EUPHAS2 registry). We included 12 patients with severe acute respiratory syndrome coronavirus 2 infection confirmed by real-time reverse transcriptase-polymerase chain reaction from nasal/oral swab, admitted to the intensive care unit between February and May 2020, who were affected by septic shock and received PMX-HP as per clinical indication of the attending physician. Septic shock was diagnosed in nine patients (75%), with a median time between symptoms onset and PMX-HP treatment of 16 (14-22) days. We identified Gram-negative bacteria in most of the microbiological cultures (N = 17, 65%), followed by Gram-positive bacteria in (N = 4, 15%), fungi (N = 3, 12%) and no growth (N = 2, 8%). Sequential Organ Failure Assessment (SOFA) score progressively improved over the next 120 hours following PMX-HP and it was associated with median endotoxin activity assay (EAA) decrease from 0.78 [0.70-0.92] at T0 to 0.60 [0.44-0.72] at T120 (P = .245). A direct correlation was observed between SOFA score and EAA. Lung Injury Score decreased and was associated with hemodynamic improvement over the same period. No statistically significant difference was observed for RIFLE score at each time point. Nine out of 12 patients (75%) required continuous renal replacement therapy because of acute kidney injury. In a series of consecutive COVID-19 patients with endotoxic shock, PMX-HP was associated with organ function recovery, hemodynamic improvement, and contemporary EAA level reduction. No PMX-HP-related complications were observed.

Endotoxins and Non-Alcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. It occurs with a prevalence of up to 25%, of which 10-20% cases progress to nonalcoholic steatohepatitis (NASH), cirrhosis, and liver cancer. The histopathology of NASH is characterized by neutrophilic infiltration, and endotoxins from gram-negative rods have been postulated as a contributing factor. Elevations in endotoxin levels in the blood can be classified as intestinal and hepatic factors. In recent years, leaky gut syndrome, which is characterized by impaired intestinal barrier function, has become a significant issue. A leaky gut may prompt intestinal bacteria dysbiosis and increase the amount of endotoxin that enters the liver from the portal vein. These contribute to persistent chronic inflammation and progressive liver damage. In addition, hepatic factors suggest that liver damage can be induced by low-dose endotoxins, which does not occur in healthy individuals. In particular, increased expression of CD14, an endotoxin co-receptor in the liver, may result in leptin-induced endotoxin hyper-responsiveness in obese individuals. Thus, elevated blood endotoxin levels contribute to the progression of NASH. The current therapeutic targets for NASH treat steatosis and liver inflammation and fibrosis. While many clinical trials are underway, no studies have been performed on therapeutic agents that target the intestinal barrier. Recently, a randomized placebo-controlled trial examined the role of the intestinal barrier in patients with NAFLD. To our knowledge, this study was the first of its kind and study suggested that the intestinal barrier may be a novel target in the future treatment of NAFLD.

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.

Selective Polymyxin Hemoperfusion in Complex Therapy of Sepsis in Children after Cardiac Surgery

BACKGROUND

To date, sepsis remains one of the main challenges of intensive care in pediatrics. Newborns with low birth weight and infants with chronic diseases and congenital disorders are particularly at risk. The incidence of infectious complications in pediatric cardiac surgery is known to be approximately 15-30%. The main etiological factor of sepsis is endotoxin.

AIM

To evaluate the efficiency and safety of polymyxin (PMX) B-immobilized column-direct hemoperfusion in complex intensive therapy of sepsis in children after cardiac surgery with cardiopulmonary bypass.

DESIGN

Prospective cohort study.

METHODS

This study enrolled 15 children, aged 9-96 months, with congenital heart diseases and with body weights of 6.2-22.5 kg. The criteria for admission were body weight >6 kg and clinical and laboratory signs of sepsis (microbiological analysis, procalcitonin [PCT] >2 ng/mL, and endotoxin activity assay [ЕАА] >0.6). Intensive care included inotropic and vasopressor support, mechanical ventilation, broad-spectrum antibiotic therapy, and PMX hemoperfusion procedures. Extracorporeal therapy was initiated within 24 h following the sepsis diagnosis. Every patient underwent 2 hemoperfusion sessions with the use of a PMX B-immobilized column; the session duration was 180 min.

RESULTS

We noted improvements in hemodynamic parameters, oxygenation index, and laboratory signs of sepsis, with decreases in the endotoxin concentration according to the EAA, PCT, and presepsin levels. The 28-day survival of the patients in this severely affected group was 80%. Main Conclusion: The inclusion of extracorporeal methods of blood purification, aimed at the selective elimination of circulating endotoxin, in the treatment of sepsis increases the survival rates of children after open heart surgery. Second Conclusion: The obtained results of sepsis therapy with PMX hemoperfusion in children after cardiac surgery enable us to suggest the sufficient safety and efficiency of the procedures in this category of severely affected patients.

Importance of Endotoxin Clearance in Endotoxemic Septic Shock: An Analysis From the Evaluating Use of PolymyxinB Hemoperfusion in a Randomized Controlled Trial of Adults Treated for Endotoxemic Septic Shock (EUPHRATES) Trial

To investigate the relationship between survival and treatment-related reduction in endotoxin activity for patients in the Evaluating Use of PolymyxinB Hemoperfusion in a Randomized controlled trial of Adults Treated for Endotoxemia and Septic shock trial with baseline endotoxin activity assay greater than or equal to 0.60 to less than 0.90 units.

Design

Post hoc analysis of a multicenter randomized controlled clinical trial.

Setting

Fifty-five tertiary hospitals in North America.

Patients

Patients with septic shock and endotoxin activity assay level greater than or equal to 0.60 to less than 0.90 and multiple organ dysfunction syndrome greater than 9.

Interventions

Two polymyxin B hemoperfusion treatments or Sham.

Measurements and Main Results

One-hundred ninety-four patients were included (88 polymyxin B and 106 Sham). We evaluated the impact of changes in endotoxin activity assay based on comparison to the median reduction from baseline to day 3 and a second method where a target post-treatment endotoxin activity assay level (day 3) was established. The population median reduction in endotoxin activity assay level was 10.4%. In patients with a greater than median reduction, there was trend toward lower mortality with polymyxin B (17.1% vs 33.3%; p = 0.07) and a significant increase in mechanical ventilation-free days (20 vs 13.5; p = 0.04). The pressure adjusted heart rate showed a significant improvement in the polymyxin B group (p = 0.02). For patients who achieved an endotoxin activity assay of less than 0.65 at day 3, the polymyxin B treated group had a trend toward a mortality reduction compared to Sham (16% vs 33%;p = 0.06) and a significant increase in ventilation-free day (20 vs 16; p = 0.05). Kaplan-Meier analysis showed a 17% reduction in mortality with polymyxin B (p = 0.04).

Conclusions

These findings suggest that reducing endotoxin activity assay levels with polymyxin B as measured by comparison to a median reduction or when a treatment target is established, may result in improvements in mortality and organ function outcomes. This article is the first to report endotoxin activity assay measurements in response to polymyxin B use versus Sham in patients with septic shock and elevated endotoxin activity assay. These findings are considered to be hypothesis generating and will need to be prospectively validated.

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.

Anti-endotoxin Properties of Polymyxin B-immobilized Fibers

Polymyxin B is an antibiotic that shows strong bactericidal activity against Gram-negative bacteria, by binding to and inactivating endotoxin. Systemic administration of polymyxin B in humans is restricted because of its nephrotoxicity and neurotoxicity, and this compound was therefore considered a strong candidate ligand for the extracorporeal selective adsorption of circulating endotoxin in the blood. Toraymyxin® is a direct hemoperfusion column that uses polymyxin B attached to an insoluble carrier to bind endotoxin in the blood. In 1994, the Japanese National Health Insurance system approved the use of Toraymyxin for the treatment of endotoxemia and septic shock.In this chapter, we will review the development, clinical use, and efficacy of Toraymyxin, examine the structure of the Toraymyxin column, and comment on the current position of Toraymyxin in the treatment of severe sepsis and septic shock. We will also highlight some potential new applications of Toraymyxin for pulmonary diseases.

Association between endotoxemia and enterocyte injury and clinical course in patients with gram-positive septic shock: A posthoc analysis of a prospective observational study

Endotoxemia often occurs in patients with gram-positive infections. The possible mechanism is thought to be bacterial translocation after enterocyte hypoperfusion injury. However, the association between endotoxemia and enterocyte injury among patients with gram-positive septic shock has never been assessed. The aim of this study was to evaluate the association between endotoxemia and enterocyte injury in gram-positive septic shock patients and to evaluate the association among endotoxemia, subsequent clinical course, and other related factors.This was a posthoc analysis of a prospective observational study that evaluated the capability of intestinal fatty acid-binding protein (I-FABP), an indicator of enterocyte injury, to predict mortality. Among 57 patients in septic shock, those whose causative microorganisms were gram positive were included. The correlation between endotoxin activity (EA), which indicates endotoxemia, and I-FABP levels upon admission to the intensive care unit (ICU), the clinical course, and other related factors were evaluated.A total of 21 patients were examined. One-third of the patients presented with high EA levels at the time of ICU admission. However, there was no significant correlation between EA and I-FABP levels (Spearman ρ = 0.002, P = .993). Additionally, high EA levels were not associated with abdominal complications after ICU admission or mortality. Similarly, high EA levels were not associated with severity scores, inotropic scores, or lactate levels upon ICU admission, which were previously reported to be factors related to high EA levels.In this posthoc analysis, no correlation was observed between endotoxemia and enterocyte injury among patients in gram-positive septic shock. Additionally, high EA levels were not associated with the clinical course and reported factors related to endotoxemia. Although our results need to be validated in a large prospective cohort study, hypoperfusion enterocyte injury might not be a cause of endotoxemia in these patients. Thus, if there is no correlation between EA and I-FABP levels, other mechanisms that induce high EA levels among patients with gram-positive septic shock should be elucidated.

Comparative Evaluation of Endotoxin Activity Level and Various Biomarkers for Infection and Outcome of ICU-Admitted Patients

Here, we concurrently measured the endotoxin activity (EA) level and levels of multiple biomarkers in patient blood obtained within 24 h after being admitted into the intensive care unit (ICU) and analyzed whether there were links between these markers and their associations with patient conditions and outcomes. The EA levels highly correlated with disease severity and patient survival, and showed a significant positive association with levels of lactate, procalcitonin, presepsin, and interleukin-6. Notably, the EA level was the marker that most highly correlated with the results of blood culture, and the presepsin level was the marker most highly correlated with the survival outcome at 28 days. Thus, the optimal biomarker should be selected based on whether it will be used to discriminate the presence of an infection or to predict survival.

Impact of hemoperfusion with polymyxin B added to hemofiltration in patients with endotoxic shock: a case-control study

Background

Septic shock is a leading cause of death in critical patients. In patients with gram-negative septic shock, hemoperfusion with polymyxin B aims to remove endotoxins from plasma. We analyzed the clinical and biological response to hemoperfusion in patients with septic shock and acute kidney injury.

Methods

This prospective case–control study in the medical–surgical intensive care unit of a university hospital included consecutive adults patients with septic shock and suspected gram-negative bacteria infection with elevated plasma endotoxin activity (EAA > 0.6 EU/ml) and acute kidney injury requiring continuous renal replacement therapy (CRRT). At onset of septic shock, half underwent CRRT plus hemoperfusion with polymyxin B for two hours a day during two consecutive days (hemoperfusion group) and half received only CRRT (control group). We measured clinical, physiological, and biological parameters (EAA, C-reactive protein, procalcitonin, and cytokines) daily during the first 5 days.

Results

We included 18 patients (male, 33%; mean age, 67.5; mean SOFA score, 11.3). Abdominal infections predominated (50% had peritonitis). At the beginning of CRRT, RIFLE classification was “failure” for 72% and “injury” for 28%. Baseline characteristics did not differ between groups. Patients in the hemoperfusion group required longer mechanical ventilation (12.4 vs. 9.4 days, p = 0.03) and CRRT (8.5 vs. 6 days, p = 0.01) than in the control group. Noradrenaline doses, lactate, procalcitonin, and C-reactive protein decreased in both groups. At day 5, EAA was significantly lower in the hemoperfusion group (0.58 EU/ml vs. 0.73 EU/ml in controls, p = 0.03). There were no significant differences between groups in other biomarkers or ICU mortality (33.3% in the treatment group vs. 44.4% in the control group, p = 0.5). No adverse effects of hemoperfusion were observed.

Conclusions

Hemoperfusion with polymyxin B added to CRRT resulted in faster decrease in endotoxin levels, but we observed no improvements in clinical, physiological, or biological parameters.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0465-8) contains supplementary material, which is available to authorized users.

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

BACKGROUND

Recent randomized trials have not found that polymyxin B hemoperfusion (PMX-HP) improves outcomes for patients with sepsis. However, it remains unclear whether the therapy could provide benefit for highly selected patients. Monocyte human leukocyte antigen (mHLA-DR) expression, a critical step in the immune response, is decreased during sepsis and leads to worsening sepsis outcomes. One recent study found that PMX-HP increased mHLA-DR expression while another found that the treatment removed HLA-DR-positive cells.

METHODS

We conducted a randomized controlled trial in patients with blood endotoxin activity assay (EAA) level ≥ 0.6. Patients in the PMX-HP group received a 2-h PMX-HP treatment plus standard treatment for 2 consecutive days. Patients in the non-PMX-HP group received only standard treatment. The primary outcome compared the groups on median change in mHLA-DR expression between day 3 and baseline. Secondary outcomes compared the groups on the mean or median change in CD11b expression, neutrophil chemotaxis, presepsin, cardiovascular Sequential Organ Failure Assessment (CVS SOFA) score, vasopressor dose, and EAA level between day 3 and baseline. We further compared the groups on mortality, ICU-free days, ventilator-free days, dialysis dependence status, renal recovery, serum creatinine, vasopressor-free days, and major adverse kidney events (MAKE 28), measured on day 28.

RESULTS

Fifty-nine patients were randomized to PMX-HP (n = 29) and non-PMX-HP (n = 30) groups. At baseline, mHLA-DR expression, CD11b, neutrophil chemotaxis, and clinical parameters were comparable between groups. The median change in mHLA-DR expression between day 3 and baseline was higher in PMX-HP patients than in patients receiving standard therapy alone (P = 0.027). The mean change in CD11b between day 3 and baseline was significantly lower in the PMX-HP group than in the non-PMX-HP group (P = 0.002). There were no significant changes from baseline in neutrophil chemotaxis, presepsin, CVS SOFA scores, vasopressor doses, or EAA level between groups. On day 28 after enrollment, mortality, ICU-free days, ventilator-free days, dialysis dependence status, renal recovery, serum creatinine, vasopressor-free days, and MAKE 28 were comparable between groups.

CONCLUSION

PMX-HP improved mHLA-DR expression in severe sepsis patients. Future studies should examine the potential benefit of PMX-HP in patients with low mHLA-DR expression.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02413541 . Registered on 3 March 2015.

Effect of Targeted Polymyxin B Hemoperfusion on 28-Day Mortality in Patients With Septic Shock and Elevated Endotoxin Level: The EUPHRATES Randomized Clinical Trial

Importance

Polymyxin B hemoperfusion reduces blood endotoxin levels in sepsis. Endotoxin activity can be measured in blood with a rapid assay. Treating patients with septic shock and elevated endotoxin activity using polymyxin B hemoperfusion may improve clinical outcomes.

Objective

To test whether adding polymyxin B hemoperfusion to conventional medical therapy improves survival compared with conventional therapy alone among patients with septic shock and high endotoxin activity.

Design, Setting, and Participants

Multicenter, randomized clinical trial involving 450 adult critically ill patients with septic shock and an endotoxin activity assay level of 0.60 or higher enrolled between September 2010 and June 2016 at 55 tertiary hospitals in North America. Last follow-up was June 2017.

Interventions

Two polymyxin B hemoperfusion treatments (90-120 minutes) plus standard therapy completed within 24 hours of enrollment (n = 224 patients) or sham hemoperfusion plus standard therapy (n = 226 patients).

Main Outcomes and Measures

The primary outcome was mortality at 28 days among all patients randomized (all participants) and among patients randomized with a multiple organ dysfunction score (MODS) of more than 9.

Results

Among 450 eligible enrolled patients (mean age, 59.8 years; 177 [39.3%] women; mean APACHE II score 29.4 [range, 0-71 with higher scores indicating greater severity), 449 (99.8%) completed the study. Polymyxin B hemoperfusion was not associated with a significant difference in mortality at 28 days among all participants (treatment group, 84 of 223 [37.7%] vs sham group 78 of 226 [34.5%]; risk difference [RD], 3.2%; 95% CI, -5.7% to 12.0%; relative risk [RR], 1.09; 95% CI, 0.85-1.39; P = .49) or in the population with a MODS of more than 9 (treatment group, 65 of 146 [44.5%] vs sham, 65 of 148 [43.9%]; RD, 0.6%; 95% CI, -10.8% to 11.9%; RR, 1.01; 95% CI, 0.78-1.31; P = .92). Overall, 264 serious adverse events were reported (65.1% treatment group vs 57.3% sham group). The most frequent serious adverse events were worsening of sepsis (10.8% treatment group vs 9.1% sham group) and worsening of septic shock (6.6% treatment group vs 7.7% sham group).

Conclusions and Relevance

Among patients with septic shock and high endotoxin activity, polymyxin B hemoperfusion treatment plus conventional medical therapy compared with sham treatment plus conventional medical therapy did not reduce mortality at 28 days.

Trial Registration

ClinicalTrials.gov Identifier: NCT01046669.

Endotoxin Activity in Neonates Undergoing Cardiac Surgery: Cohort Study

BACKGROUND

Endotoxemia in pediatric cardiac surgical patients is poorly understood. The endotoxin activity assay (EAA) levels were examined in neonates undergoing cardiac surgery in order to assess their reference levels and their association with other pre-, intra-, and postoperative risk factors for gut hypoperfusion. We finally observed if refeeding was associated with modification of endotoxin levels.

METHODS

In a prospective cohort study, neonates undergoing surgery for correction or palliation were enrolled. Preterm birth, weight below 1.5 kg, the need for extracorporeal membrane oxygenation, and urgent surgery were exclusion criteria.

RESULTS

Among the 26 enrolled neonates, 12 underwent on-pump and 14 off-pump surgery, 22 received a preoperative infusion of prostaglandin E2. Overall, 11 patients were surgically corrected and 15 received a palliation. Endotoxin activity assay baseline levels were inversely correlated with age at surgery ( r = -.50, P = .006) and they increased to postoperative day2 ( P = .002). On-pump versus off-pump surgery ( P =.36) and surgical palliation with a Blalock-Taussig shunt versus correction ( P = .45) did not predict increase in EAA levels. Aortic clamping for coarctation repair was associated with the lowest levels ( P = .04). Systolic, mean, and diastolic pressures were associated with EAA levels ( r = -.55, P = .01; r = -.45, P = .02; r = -.37, P = .04, respectively). Endotoxin activity assay levels after refeeding were similar to baseline levels. Patients with abdominal distension and feeding intolerance showed higher median peak EAA levels (0.7, 0.66-1.11) than asymptomatic patients (0.53, 0.35-0.64; P = .01).

CONCLUSIONS

Endotoxin activity assay levels increase after elective neonatal surgery and are not modified by refeeding. High postoperative levels may predict feeding intolerance.

Palmitate-induced lipotoxicity is crucial for the pathogenesis of nonalcoholic fatty liver disease in cooperation with gut-derived endotoxin

Although previous studies have indicated important roles of palmitate, a saturated fatty acid, in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), it remains unclear how palmitate contributes to inflammation and fibrosis in the liver. Administration of palmitate in high fat diet (HFD)-fed but not basal diet (BD)-fed mice resulted in an increase in serum alanine aminotransferase (ALT) levels. Surprisingly, combined administration of very low dose lipopolysaccharide in palmitate-treated mice led to a marked increase in serum ALT levels despite BD-fed conditions. Administration of palmitate alone in BD-fed mice caused inflammatory cell infiltration and liver fibrosis mediated by the toll-like receptor 4 pathway without ALT elevation. In addition, a significant correlation between serum free fatty acid levels and liver fibrosis stage was observed in patients with NAFLD. These results indicate that palmitate may play crucial roles in the pathogenesis of NAFLD in the presence of gut-derived endotoxin.

Endotoxin Metabolism Reflects Hepatic Functional Reserve in End-Stage Liver Disease

BACKGROUND

The hepatic clearance of endotoxin (Et) may reflect hepatic functional reserve and ischemic injury to hepatocytes. Therefore, we examined the relationships between Et activity (EA) and the metrics Pediatric End-Stage Liver Disease (PELD)/Model of End-Stage Liver Disease (MELD) score and alanine transaminase (ALT) levels in the postoperative period.

METHODS

We performed 8 living-donor liver transplantations (LDLTs) for biliary atresia at our center from April 2012 to December 2012. EA was measured by means of an Et activity assay (EAA) in samples collected from a vein 1 day before LDLT, from the portal vein during the intraoperative anhepatic phase, from an artery 1 hour after reperfusion, from an artery on postoperative day (POD) 1, and from an artery or vein at PODs 7 and 14.

RESULTS

EAs generally remained at low levels. EA at the reperfusion period was significantly lowest. The correlation coefficient for the preoperative MELD/PELD score and the EAA was 0.837, and the corresponding P value was .009; thus, there was a significant relationship between the preoperative MELD/PELD score and the EAA. The correlation coefficients for ALT at POD 1 and EA during the anhepatic phase, at 1 hour after reperfusion, and at POD 1 were 0.64, 0.43, and 0.38, respectively, and the P values for these correlations were .08, .67, and .34. Thus, we observed that ALT and EA generally tended to be somewhat directly correlated, but no significant relationships between these 2 metrics were observed.

CONCLUSIONS

Endotoxin metabolism reflects the hepatic functional reserve capacity of end-stage liver disease.

IL-7 and procalcitonin are useful biomarkers in the comprehensive evaluation of the severity of acute cholangitis

BACKGROUND

The incidence of biliary tract infection (BTI), especially healthcare-associated cholangitis, is increasing. However, there are few reports concerning biomarkers of acute cholangitis. We therefore performed an exhaustive investigation of several biomarkers.

METHODS

We retrospectively measured 11 cytokines, six chemokines and procalcitonin (PCT), and endotoxin activity assay (EAA) values (IRB: 110512019) of 61 samples with acute cholangitis.

RESULT

The 28-day mortality rate was 9.8%. The levels of most cytokines and chemokines were significantly correlated with each other. A low IL-7 level was found to predict blood culture positivity. Low IL-7 level was also found to predict disseminated intravascular coagulation. Low IL-7 levels and a high PCT level were found to be predictors of severe cholangitis. The 28-day mortality in the group of patients with an IL-7 level of ≤6.0 and a PCT level of >0.5 was 18.2%. It was significantly higher than in the other group.

CONCLUSION

The combined use of IL-7 and PCT may be useful for evaluating severe acute cholangitis; these results may suggest that severe acute cholangitis is affected by immunosuppressive changes.

History and current status of polymyxin B-immobilized fiber column for treatment of severe sepsis and septic shock

Toraymyxin^® (Toray Medical Co., Ltd, Tokyo, Japan) has been developed as a direct hemoperfusion column that contains polymyxin B‐immobilized fiber to bind endotoxins in patients’ blood. Toraymyxin was approved by the Japanese National Health Insurance system for the treatment of endotoxemia and septic shock in 1994. Since then, PMX (defined as direct hemoperfusion with Toraymyxin) has been safely used in more than 100 000 cases in emergency and intensive care units in Japan. Toraymyxin is currently available for use in clinical settings in 12 countries outside of Japan. We reviewed and analyzed the development, clinical use, and efficacy of Toraymyxin, and assessed the current status of Toraymyxin use for the treatment of severe sepsis and septic shock. Our review shows that PMX appeared to be effective in improving hemodynamics and respiratory function in septic shock requiring emergency abdominal surgery. Recent large‐scale ranomized controlled trialscould not demonstrate whether prognosis is improved by PMX. However, the latest meta‐analysis revealed that PMX significantly decreased mortality in patients with severe sepsis and septic shock. Combination of PMX with continuous hemodiafiltration and longer duration of PMX might be an effective strategy to improve survival in such patients.

The Level of Oxidative Neutrophil Response When Determining Endotoxin Activity Assay: A New Biomarker for Defining the Indications and Effectiveness of Intensive Care in Patients with Sepsis

Background. To analyse the clinical informativity of the neutrophil oxidative response level (“Response”) during an Endotoxin Activity Assay (EAA) as a new biomarker defining the indications and effectiveness of intensive care in cardiac surgical patients with septic complications. Methods. Blood samples were taken from 198 adult patients who were admitted to the ICU after cardiac surgery (SIRS: 34, MODS: 36, and sepsis: 128). The composite of laboratory studies included CRP, PCT, EAA with “Response” level, and presepsin. Results. 83% of patients had a “normal” neutrophil response, 12% of patients had a low neutrophil response, and 5% of patients had a critically low neutrophil response. Patients with critically low responses had the lowest values of the EAA and the highest concentrations of PSP and D-dimer (p < 0.05). Conclusions. EAA results should be interpreted with the level of neutrophil response. “Response” > 0.5 has a negative predictive value; the EAA < 0.6 at “Response” < 0.5 may indicate a high level of endotoxaemia.

Lubiprostone improves intestinal permeability in humans, a novel therapy for the leaky gut: A prospective randomized pilot study in healthy volunteers

BACKGROUND AND AIMS

The barrier function of the small intestinal mucosa prevents the introduction of undesired pathogens into the body. Breakdown of this barrier function increases intestinal permeability. This has been proposed to induce not only gastrointestinal diseases, including inflammatory bowel disease and irritable bowel syndrome, but also various other diseases, including allergies, diabetes mellitus, liver diseases, and collagen diseases, which are associated with this so called "leaky gut syndrome." As such, a method to prevent leaky gut syndrome would have substantial clinical value. However, no drugs have been demonstrated to improve disturbed intestinal permeability in humans to date. Therefore, we investigated whether a drug used to treat chronic constipation, lubiprostone, was effective for this purpose.

METHODS

Healthy male volunteers were treated with lubiprostone (24 μg/day) for 28 days. Intestinal permeability was evaluated by measuring the lactulose-mannitol ratio (LMR) after administration of diclofenac and compared with an untreated group. The examination was conducted three times in total, i.e., at baseline before diclofenac administration and after 14 and 28 days of lubiprostone treatment. Blood endotoxin activity was also evaluated at the same time points.

RESULTS

The final analysis was conducted on 28 subjects (14 in the lubiprostone group and 14 in the untreated group). The LMR after 28 days of treatment was significantly lower in the lubiprostone group than that in the untreated group (0.017 vs. 0.028, respectively; 95% confidence interval, -0.022--0.0001; p = 0.049). Blood endotoxin activity exhibited almost no change over time in the lubiprostone and untreated groups and displayed no significant differences at any time point of examination.

CONCLUSIONS

This study is the first to report an improvement in leaky gut using an available drug in humans. The result suggests that lubiprostone may prevent and ameliorate "leaky gut syndrome". However, a pivotal trial is needed to confirm our finding.

In vitro flow-through assay for rapid detection of endotoxin in human sera: A proof-of-concept

An increase in endotoxin concentration in the bloodstream can trigger activation of innate immune response leading to septic shock. There is currently no method available for rapid endotoxin detection at a patient's bedside. We demonstrate a simple, portable and cost-effective strategy to measure endotoxin levels in human serum within 5min using a flow-through assay. A drop of serum containing LPS was spotted on an endotoxin-affinity membrane placed over high-wicking absorbent pads. Subsequent addition of polymyxin B sulfate drug-conjugated gold nanoparticles allowed concentration-dependent visualization of spots by the naked eye in the clinically-relevant range of 10pg/mL to 10ng/mL. The results were quantified using a concentration-calibrated color chart and the assay performance was tested with archival plasma samples of 18 known septicemia patients. The results showed a reasonably good correlation with the patients' hematological data. This proof-of-concept study puts forth an interesting alternative for early septicemia diagnosis in future.

Plasmapheresis and other extracorporeal filtration techniques in critical patients

Plasmapheresis is an extracorporeal technique that eliminates macromolecules involved in pathological processes from plasma. A review is made of the technical aspects, main indications in critical care and potential complications of plasmapheresis, as well as of other extracorporeal filtration techniques such as endotoxin-removal columns and other devices designed to eliminate cytokines or modulate the inflammatory immune response in critical patients.

Endotoxemia-menace, marker, or mistake?

Endotoxemia is in its scientific ascendancy. Never has blood-borne, Gram-negative bacterial endotoxin (LPS) been invoked in the pathogenesis of so many diseases-not only as a trigger for septic shock, once its most cited role, but also as a contributor to atherosclerosis, obesity, chronic fatigue, metabolic syndrome, and many other conditions. Finding elevated plasma endotoxin levels has been essential supporting evidence for each of these links, yet the assays used to detect and quantitate endotoxin have important limitations. This article describes several assays for endotoxin in plasma, reviews what they do and do not measure, and discusses why LPS heterogeneity, LPS trafficking pathways, and host LPS inactivation mechanisms should be considered when interpreting endotoxin assay results.

The effects of direct hemoperfusion using a polymyxin B-immobilized column in a pig model of severe Pseudomonas aeruginosa pneumonia

Background

Hemoperfusion through a column containing polymyxin B-immobilized fiber (PMX-HP) is beneficial in abdominal sepsis. We assessed the effects of PMX-HP in a model of severe Pseudomonas aeruginosa pneumonia.

Methods

Eighteen pigs with severe P. aeruginosa pneumonia were mechanically ventilated for 76 h. Pigs were randomized to receive standard treatment with fluids and vasoactive drugs, or standard treatment with two 3-h PMX-HP sessions. Antibiotics against P. aeruginosa were never administered. We assessed endotoxemia through the endotoxin activity assay (EA). We measured the static lung elastance, ratio of arterial partial pressure per inspiratory fraction of oxygen (PaO₂/FIO₂), mean arterial pressure, cardiac output, systemic vascular resistance and inotropic score. Finally, every 24 h, we assessed complete blood count.

Results

In comparison with the control group, PMX-HP decreased percentage of circulating neutrophils from 47.4 ± 13.8 to 40.8 ± 11.5 % (p = 0.009). In a subgroup of animals with the worst hemodynamic impairment, EA in the control and PMX-HP groups was 0.50 ± 0.29 and 0.29 ± 0.14, respectively (p = 0.018). Additionally, in the control and PMX-HP groups, static lung elastance was 26.9 ± 8.7 and 25.3 ± 7.5 cm H₂O/L (p = 0.558), PaO₂/FIO₂ was 347.3 ± 61.9 and 356.4 ± 84.0 mmHg (p = 0.118), mean arterial pressure was 81.2 ± 10.3 and 81.6 ± 13.1 mmHg (p = 0.960), cardiac output was 3.30 ± 1.11 and 3.28 ± 1.19 L/min (p = 0.535), systemic vascular resistance was 1982.6 ± 608.4 and 2011.8 ± 750.0 dyne/s/cm^–5 (p = 0.939), and inotropic score was 0.25 ± 0.10 and 0.26 ± 0.18 (p = 0.864).

Conclusions

In mechanically ventilated pigs with severe P. aeruginosa pneumonia, PMX-HP does not have any valuable clinical benefit, and studies are warranted to fully evaluate a potential role of PMX-HP in septic shock associated with severe pulmonary infections.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-016-0155-3) contains supplementary material, which is available to authorized users.

Endotoxemia Following Multiple Trauma: Risk Factors and Prognostic Implications

OBJECTIVE

To evaluate the prevalence and time course of systemic endotoxemia following severe multiple trauma, to define its risk factors, and to explore the correlation between post-trauma endotoxemia and organ dysfunction.

DESIGN

Prospective single-center cohort study.

SETTING

Emergency department and ICU of adult tertiary care level I trauma center.

PATIENTS

Forty-eight severely injured (Injury Severity Score ≥ 16) patients, admitted to ICU within 24 hours of injury.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Endotoxemia was not evident on initial presentation, but developed subsequently in 75% of patients, even in the absence of Gram-negative infection. Nonsurviving patients had higher endotoxin levels than survivors on day 1 (endotoxemia, 0.48 vs 0.28; p = 0.048). Shock at admission, or surgery within the first 48 hours after trauma, was associated with higher endotoxin levels and predicted subsequent maximal endotoxemia, after adjusting for other significant covariates. Maximal endotoxemia levels were higher in patients who developed organ dysfunction, reflected in a cumulative Multiple Organ Dysfunction Score greater than 25, and patients with an intermediate endotoxemia level (≥ 0.4) had more cardiovascular dysfunction.

CONCLUSIONS

It is the first study to detect increasing levels of endotoxemia following multiple trauma. Shock and early surgery predict the development of endotoxemia; endotoxemia is particularly associated with cardiovascular dysfunction. However, Gram-negative infections are uncommon in these patients, suggesting that the gastrointestinal tract is the dominant reservoir of endotoxin. Endotoxin may be an appropriate therapeutic target in patients who have sustained severe multiple trauma.

Evaluation of Endotoxemia After Pediatric Cardiac Surgery With the Endotoxin Activity Assay: An Exploratory Prospective Cohort Study

OBJECTIVE

Children with congenital heart diseases undergoing surgery with cardiopulmonary bypass are exposed to a high risk of perioperative endotoxemia. The aim of our study was to prospectively evaluate endotoxin assay activity reference levels during the postoperative phase of infants undergoing cardiac surgery for congenital heart disease and to assess their association with perioperative variables and postoperative infections.

DESIGN

Prospective exploratory single-center cohort study.

SETTING

Tertiary pediatric cardiac ICU.

PATIENTS

Infants undergoing cardiac surgery with cardiopulmonary bypass were enrolled. Exclusion criteria were preoperative suspected or confirmed infection, the need for extracorporeal membrane oxygenation or a ventricular assist device in any perioperative phase, surgery for heart transplantation, and/or urgent surgery.

INTERVENTIONS

Serial measurements of endotoxin assay activity were performed at baseline, pediatric cardiac ICU arrival, postoperative day 1 and 2.

MEASUREMENTS AND MAIN RESULTS

Twenty-five patients were enrolled. Overall, 14 of 25 patients (58%) presented at least one endotoxin assay activity level greater than 0.4 during the study period (normal level is < 0.4). Endotoxin assay activity levels tended to significantly increase from baseline to postoperative day 1 and 2 and from pediatric cardiac ICU arrival to postoperative day 2 (p < 0.0001). Endotoxin assay activity greater than 0.6 predicted Gram-negative infections with a sensitivity of 0.40, a specificity of 0.95, a positive predictive value of 0.66, and a negative predictive value of 0.86. At multivariable regression, endotoxin assay activity on postoperative day 1 resulted independently associated with cardiopulmonary bypass duration, lactate, temperature peak, and vasoactive inotropic score at pediatric cardiac ICU arrival. Children with endotoxin assay activity levels greater than 0.6 (vs all the others) showed a significantly higher median (interquartile) number of ventilation days: 8 (2-39) versus 1.5 (1-3 (p = 0.02).

CONCLUSIONS

This exploratory study showed that endotoxin assay activity levels in infants undergoing cardiopulmonary bypass are frequently above 0.4 and peak 24-48 hours after surgery and appear to be associated with perioperative impaired organ perfusion. Endotoxin assay activity is not useful to predict Gram-negative infections.

Endotoxin detection in full blood plasma in a theranostic approach to combat sepsis

A qualitative piezoelectric biosensor assay alternative for the detection of bacterial endotoxin is described to perform measurements in full human blood plasma in a real-time and label-free advanced fashion.