Endotoxemic Shock: A Molecular Phenotype in Sepsis

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 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.

Novel insights at the crossroads of antibiotic use and cancer risk

The continuous use of antibiotics is associated with the spread of antimicrobial resistances and the not yet clear link to cancer development. Many conventional antibiotics have already shown different effects on a variety of cancer types raising questions for their rational use in cancer. However, discrepancy in the observed trend for some antibiotics reducing cancer development and being associated with higher risk of cancer underscores the lack of understanding the complex link between antibiotics and cancer. Here, we briefly summarize the possible antibiotic-mediated effects on cancer and conclude that those effects can be direct via i) specific targeting of tumor/cancer, ii) antimicrobial activity and iii) immunomodulatory activity whereby iv) indirectly caused effects primarily affect immune equilibrium between bacteria, cancer and immune cells. Furthermore, we also conclude that there is a great need for bulk profiling, comprehensive screening programs in all countries and in-depth studies to understand the risks and benefits of antibiotic use.

Sepsis-associated acute kidney injury: consensus report of the 28th Acute Disease Quality Initiative workgroup

Sepsis-associated acute kidney injury (SA-AKI) is common in critically ill patients and is strongly associated with adverse outcomes, including an increased risk of chronic kidney disease, cardiovascular events and death. The pathophysiology of SA-AKI remains elusive, although microcirculatory dysfunction, cellular metabolic reprogramming and dysregulated inflammatory responses have been implicated in preclinical studies. SA-AKI is best defined as the occurrence of AKI within 7 days of sepsis onset (diagnosed according to Kidney Disease Improving Global Outcome criteria and Sepsis 3 criteria, respectively). Improving outcomes in SA-AKI is challenging, as patients can present with either clinical or subclinical AKI. Early identification of patients at risk of AKI, or at risk of progressing to severe and/or persistent AKI, is crucial to the timely initiation of adequate supportive measures, including limiting further insults to the kidney. Accordingly, the discovery of biomarkers associated with AKI that can aid in early diagnosis is an area of intensive investigation. Additionally, high-quality evidence on best-practice care of patients with AKI, sepsis and SA-AKI has continued to accrue. Although specific therapeutic options are limited, several clinical trials have evaluated the use of care bundles and extracorporeal techniques as potential therapeutic approaches. Here we provide graded recommendations for managing SA-AKI and highlight priorities for future research.

Sirtuin 1 activator alleviated lethal inflammatory injury via promotion of autophagic degradation of pyruvate kinase M2

Upregulation of pyruvate kinase M2 (PKM2) is critical for the orchestration of metabolism and inflammation in critical illness, while autophagic degradation is a recently revealed mechanism that counter-regulates PKM2. Accumulating evidence suggests that sirtuin 1 (SIRT1) function as a crucial regulator in autophagy. The present study investigated whether SIRT1 activator would downregulate PKM2 in lethal endotoxemia via promotion of its autophagic degradation. The results indicated that lethal dose of lipopolysaccharide (LPS) exposure decreased the level of SIRT1. Treatment with SRT2104, a SIRT1 activator, reversed LPS-induced downregulation of LC3B-II and upregulation of p62, which was associated with reduced level of PKM2. Activation of autophagy by rapamycin also resulted in reduction of PKM2. The decline of PKM2 in SRT2104-treated mice was accompanied with compromised inflammatory response, alleviated lung injury, suppressed elevation of blood urea nitrogen (BUN) and brain natriuretic peptide (BNP), and improved survival of the experimental animals. In addition, co-administration of 3-methyladenine, an autophagy inhibitor, or Bafilomycin A1, a lysosome inhibitor, abolished the suppressive effects of SRT2104 on PKM2 abundance, inflammatory response and multiple organ injury. Therefore, promotion of autophagic degradation of PKM2 might be a novel mechanism underlying the anti-inflammatory benefits of SIRT1 activator.