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The release of "neutrophil extracellular traps" (NETs) has been identified as a novel immune response in innate immunity. Neutrophil extracellular traps are composed of neutrophil-derived circulating free DNA (cf-DNA), histones, and neutrophil cytoplasm-derived proteins such as proteases. Here, we studied the putative predictive value of plasma cf-DNA/NETs for the development of sepsis and mortality after multiple trauma. In a prospective pilot study with 45 multiple trauma (Injury Severity Score>16) patients, cf-DNA was directly quantified in plasma. Blood samples were sequentially obtained daily from admission to our Trauma Center until day 10. Because of limited intensive care unit (ICU) stay of less than 3 days, 8 patients have been excluded, resulting in 37 patients that were evaluated. Time kinetics of cf-DNA/NETs was compared with C-reactive protein (CRP), interleukin (IL) 6, leukocyte counts, and myeloperoxidase. The severity of the injury was calculated on the basis of the Injury Severity Score, as well as Multiple Organ Dysfunction Score, Sequential Organ Failure Assessment, and Simplified Acute Physiology Score II on ICU. Initially high cf-DNA/NETs values (>800 ng/mL) with recurrent increased values between days 5 to 9 were associated with subsequent sepsis, multiple organ failure, and death. In conjunction with cf-DNA/NETs, IL-6 was significantly elevated after admission. However, the development of a second hit was not indicated by IL-6. In contrast to cf-DNA/NETs, no difference in CRP kinetics was observed between patients with and without development of sepsis. Circulating free DNA/NETs kinetics rather followed kinetics of Multiple Organ Dysfunction Score, Sepsis-related Organ Failure Assessment, leukocyte counts, and partially of myeloperoxidase. Circulating free DNA/NETs seems to be a valuable additional marker for the calculation of injury severity and/or prediction of inflammatory second hit on ICU. However, a large clinical trial with severely injured patients should confirm the prognostic value of neutrophil-derived cf-DNA/NETs.

Sepsis is a leading cause of morbidity and mortality worldwide. Dysregulated immune response to infection is a hallmark of sepsis, leading to life‐threatening organ dysfunction or even death. Advancing knowledge of the complex pathophysiological mechanisms has been a strong impetus for the development of therapeutic strategies aimed at rebalancing the immune response by modulating the excess of both pro‐ and anti‐inflammatory mediators. There is a wealth of preclinical data suggesting clinical benefits of various extracorporeal techniques in an attempt to modulate the exaggerated host inflammatory response. However, the evidence base is often weak. Owing to both an advancing comprehension of the pathophysiology and the increased quality of clinical trials, progress has been made in establishing extracorporeal therapies as part of the general therapeutic canon in sepsis. We aim for a comprehensive overview of the technical aspects and clinical applications in the context of the latest evidence concerning these techniques. [ABSTRACT FROM AUTHOR]

Liver dysfunction (LD) and liver failure are associated with poor outcome in critically ill patients. In patients with severe sepsis or septic shock, LD occurred in nearly 19% of patients. An early diagnosis of LD at time of initial damage of the liver can lead to a better prognosis of these patients because an early start of therapy is possible. We performed a second prospective study with septic patients to test a new cell-based cytotoxicity device (biosensor) to evaluate clinical relevance for early diagnosis of LD and prognostic capacity. In the clinical study, 99 intensive care unit patients were included in two groups. From the patients of the septic group (n = 51, SG), and the control (non-septic) group [n = 49, control group (CG)] were drawn 20 ml blood at inclusion, after 3, and 7 days for testing with the biosensor. Patients’ data were recorded for hospital survival, organ function, and demographic data, illness severity [acute physiology and chronic health evaluation (APACHE) II-, sepsis-related organ failure assessment (SOFA) scores], cytokines, circulating-free deoxyribonucleic acid/neutrophil-derived extracellular traps (cf-DNA/NETs), microbiological results, and pre-morbidity. For the developed cytotoxicity test, the human liver cell line HepG2/C3A was used. Patients’ plasma was incubated in a microtiter plate assay with the test cells and after 6 days incubation the viability (trypan blue staining, XTT-test) and functionality (synthesis of albumin, cytochrome 1A2 activity) was analyzed. An impairment of viability and functionality of test cells was only seen in the SG compared with the CG. The plasma of non-survivors in the SG led to a more pronounced impairment of test cells than the plasma of survivors at inclusion. In addition, the levels of cf-DNA/NETs were significantly higher in the SG at inclusion, after 3, and after 7 days compared with the CG. The SG showed an in-hospital mortality of 24% and the values of bilirubin, APACHE II-, and SOFA scores were markedly higher at inclusion than in the CG. Hepatotoxicity of septic plasma was already detected with the liver cell-based biosensor at inclusion and also in the course of disease. The biosensor may be a tool for early diagnosis of LD in septic patients and may have prognostic relevance. [ABSTRACT FROM AUTHOR]

Abstract: Posttrauma apoptosis resistance of neutrophils (PMN) is related to overshooting immune responses, systemic inflammatory response syndrome (SIRS) and multiple organ failure (MOF). Recently, we have shown that the apoptosis resistance in circulating PMN from severely injured patients which is known to be mediated by high serum levels of pro-inflammatory cytokines can be overcome by the activation of Fas death receptor. Here, we aimed to study whether stimulation of surface Fas leads to the inactivation of hyperactivated PMN from critically ill patients with SIRS. PMN from 23 multiple trauma patients (mean injury severity score (ISS) 34±1.9) were isolated at day 1 after admission to the trauma center. PMN from 17 volunteer blood donors served as controls. Neutrophil activity has been determined after ex vivo short (1h) and long-term (4h) stimulation of freshly isolated PMN with immobilized agonistic anti-Fas antibodies. We found neutrophil chemotactic migration in response to IL-8, phagocytosis and oxidative burst to be significantly inhibited in control cells already after short-term (1h) Fas stimulation. In contrast, inactivation of trauma PMN by agonistic anti-Fas antibodies was found to be efficient only after long-term (4h) incubation of cells with agonistic antibodies. Thus, in trauma PMN down-regulation of neutrophil activity seems to be delayed when compared to cells isolated from healthy controls, suggesting impaired susceptibility for Fas stimulation in these cells. Interestingly, whereas Fas-mediated inhibition of phagocytosis and oxidative burst could be prevented by the broad range caspase inhibitor t-butoxycarbonyl-aspartyl(O-methyl)-fluoromethyl ketone (BocD-fmk), the chemotactic activity in response to IL-8 was unaffected. In conclusion, we demonstrate that stimulation of neutrophil Fas does not only initiate apoptosis but also induces inhibition of neutrophil functions, partially by non-apoptotic signaling. [Copyright &y& Elsevier]