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.

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.

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.

Endotoxin Adsorbent Therapy in Severe COVID-19 Pneumonia

<b><i>Introduction:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusions:</i></b> 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.

An in vitro study on factors affecting endotoxin neutralization in human plasma using the Limulus amebocyte lysate test

Endotoxin neutralization, caused by plasma components, makes it difficult to detect endotoxins in human blood. In this study, we investigated which factors influence the recovery of endotoxins using limulus ameobocyte lysate (LAL)-based assays. The individual factors that were examined in more detail were lipoprotein content, type of blood anticoagulation, kinetics and serum levels of divalent cations. Furthermore, it was investigated whether there is a direct correlation between LAL activity and monocyte activation. We could show that polyanionic heparin increases endotoxin recovery in blood, while citrate anticoagulation promotes endotoxin neutralization. Furthermore, we could show that the endotoxin activity in human plasma and serum decreases strongly over time. Time-dependent endotoxin neutralization reaches its maximum after 4–6 h incubation. By means of filtration tests we could determine that endotoxins in the plasma bind to lipoproteins but do not influence their activity. Comparative measurements have shown that high LAL activity of endotoxins in plasma simultaneously possesses high monocyte activating properties in whole blood. For the maximum recovery of endotoxins in human blood the physiological calcium and magnesium concentrations are sufficient. In this study, it was shown that the endotoxin neutralizing plasma components have a molecular weight similar to β2-microglobulin (11.7 kDa). For the exact identification of the endotoxin neutralizing plasma components, which caused a modulation of the immunostimulating endotoxin activity, further investigations have to be carried out in the future.

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.

The Use of Selective Hemosorption of Lipopolysaccharides in the Complex Treatment of Sepsis

Background Sepsis and septic shock are formidable and complications in surgery with mortality 20–50%. In the pathogenesis of sepsis, a significant role belongs to bacterial endotoxin (LPS - liposaccharide).Aim of study Assessment of the efficacy of selective lipopolysaccharides hemosorption (SLH) in treatment of sepsis.Material and methods We examined 65 patients with developed sepsis or suspected presence of gram-negative infection. Patients were retrospectively divided into two groups. In Group 1, 27 patients received Polymyxin B hemoperfusion using Toraymyxin cartridges. In Group 2 (38 patients), adsorber Alteco (LPSA) was used.Results It was established that 28-day mortality was 11.1% in Polymyxin group and 28.9% in LPS group A, p = 0.091, 60-day mortality was 33.3 and 55.3%, respectively (p=0.065). The use of SLH contributed to a decrease in the activity of endotoxin (EAA) from 0.52 (0.39; 0.65) to 0.40 (0.36; 0.57) EU (p=0.330) in Polymyxin group and from 0.59 ( 0.42; 0.72) to 0.54 (0.40; 0.81) EU ( p = 0.981) in the LPS-A group. At the same time, the level of procalcitonin (PCT) in the blood statistically significantly decreased from 8.4 (3.6; 29.0) to 4.8 (1.9; 36.3) ng/ml (p=0.0117) only in the LPS-A group. The level of C-reactive protein (CRB) in the blood statistically significantly decreased only in the Polymyxin group, from 205 (154; 264) to 162 (106; 202) mg/L (p<0.001). After SPH procedures, there was a tendency to a decrease in the level of blood cytokines in both groups. Conclusion 1. The trend of better survival among patients was noted during hemoperfusion when using Polymyxin B in comparison with the results of adsorption of lipopolysaccharide with Alteco cartridges: so, 28-day mortality was 11.1 and 28.9%, respectively (statistically not significant).2. As a result, the procedure of selective lipopolysaccharides hemosorbtion on hemosorbents with Polymyxin B in blood significantly decreased level of C-reactive protein (21%), there was statistically insignificant decrease in the level of endotoxin activity (23.1%), lipopolysaccharide binding protein (21.6%), procalcitonin (2.4 times), presepsin (20%), as well as the level of interleukin-6 (3.4 times) and interleukin-10 (1.6 times) . Adsorption of lipopolysaccharide with Alteco cartridges leads to a statistically significant reduction of procalcitonin in blood (1.8 times), and statistically insignificant decrease of: endotoxin activity (9.3%), lipopolysaccharide binding protein (28.6%), interleukin-6 (3.8 times), interleukin-10 (7.1 times) and soluble receptor to interleukin-2 (2.2 times).