Cellular and Molecular Markers of Outcome in Septic Shock (original) (raw)

Early Assessment of Leukocyte Alterations at Diagnosis of Septic Shock

Shock, 2010

A dramatic decrease in circulating lymphocyte number is regularly described after septic shock. However, it is unknown how early this alteration develops after diagnosis of shock and if it remains stable over time. Twenty-one septic shock patients with no comorbidities were included within 2 h after the beginning of vasopressive treatment. Flow cytometry phenotyping of circulating leukocyte subpopulations and quantitative real-time polymerase chain reaction of T-bet, GATA-3, FOXP3, and ROR+ mRNA were performed in patients from the diagnosis of shock and every 6 h during the subsequent 48 h. From their admission in the intensive care unit, patients present with major alterations of circulating leukocyte count (leukocytosis, neutrophilia, and major lymphopenia). The numbers of every lymphocyte subpopulations (T, B, and natural killer cells) were diminished. Gene expression analysis of transcription factors specific for T H 1, T H 2, CD4 + CD25 + regulatory, and T H 17 lymphocytes showed a severe decrease in comparison with healthy individuals' values. These alterations remain stable during the first 48 h after inclusion in the protocol despite early and aggressive resuscitation and antibiotherapy administered in patients. At the time of diagnosis of shock and admission in the intensive care unit, septic patients already present with severe lymphopenia involving every lymphocyte subsets including CD4 + T-cell subpopulations. No significant variation could be detected within the first 48 h. This should be taken into account in the forthcoming clinical trials testing immunomodulating therapies in septic shock patients.

THE OCCURRENCE OF SEVERE SEPSIS AND SEPTIC SHOCK ARE RELATED TO DISTINCT PATTERNS OF CYTOKINE GENE EXPRESSION

Shock, 2006

Patient response to acute bacterial infection is highly variable. Differing outcomes in this setting may be related to variations in the immune response to an infectious insult. Using quantitative real-time polymerase chain reaction, we quantified gene expression of the tumor necrosis factor !(TNF!), interferon + (IFN+), and interleukin 10 (IL10), IL12p35, and IL4 genes in 3 patient groups. These groups consisted of an intensive care unit (ICU) cohort who presented with severe sepsis or septic shock, a group of noncritically ill ward patients with documented Gram-negative bacteremia, and a group of healthy controls. Greater interleukin 10 messenger RNA (mRNA) levels were detected in the ICU group in comparison with both the bacteremic and control groups (P G 0.0001). More TNF-! mRNA was detected in the ICU group when compared with the control group (P G 0.0001). However, TNF-! mRNA was most abundant in the bacteremic group (P = 0.0007). Lesser IFN-+ mRNA levels were detected in the ICU group when compared with both the bacteremic and control groups (P G 0.0003). Cytokine mRNA levels were not associated with the occurrence of shock upon admission to ICU. On the seventh day of ICU stay, the presence of shock was associated with lesser IFN-+ mRNA (P = 0.0004) and lesser TNF-! mRNA (P = 0.001). Survivors had greater TNF-! mRNA copy numbers on day 7 of ICU stay than nonsurvivors (P = 0.002). We conclude that a proinflammatory response is the appropriate response in the setting of infection and is associated with lesser requirements for inotropes and lesser mortality. Quantitative real-time polymerase chain reaction can be used to predict infection outcome in clinically relevant situations where enzyme-linked immunosorbent assay testing has proved disappointing.

Prognostic values of serum cytokines in septic shock

Intensive Care Medicine, 1994

cantly associated with a favourable outcome. IL6 is certainly involved in the pathophysiology of septic shock but further studies are required to determine whether or not it is directly involved in the mediation of late and lethal complications of septic shock. Serum lactate levels and oxygen-derived variables were of less interest as prognostic factors.

Pathophysiologic mechanisms in septic shock

Laboratory Investigation a Journal of Technical Methods and Pathology, 2014

The systemic inflammatory response that occurs in the septic patient as a result of an infectious insult affects multiple organs and systems, causing numerous physiological derangements. Alterations in phagocytic, lymphocytic and endothelial cell function and immune regulation are evident, leading to heterogeneity in a host's response to a septic challenge. In addition, the normal hemostatic balance shifts toward a procoagulant state through alterations in tissue factor, antithrombin, protein C and the inhibition of fibinolysis, which can result in thrombus formation and paradoxical hemostatic failure. In an effort to diagnose sepsis and predict outcomes, biomarkers such as C-reactive protein, pro-calcitonin, pro-and anti-inflammatory cytokines have been investigated with varying results. Targeted therapies for sepsis, most notably Xigris (recombinant human activated protein C), have proven unsuccessful and treatment continues to remain reliant on source control, antibiotics and supportive interventions, specifically early goal-directed therapy. This brief review gives an overview of the immunopathologic and coagulopathic alterations that occur in sepsis, soluble inflammatory mediators as potential diagnostic and prognostic biomarkers, and the clinical management of the septic patient.

Early Biomarker Activity in Severe Sepsis and Septic Shock and A Contemporary Review of Immunotherapy Trials

Shock, 2013

Improving time to diagnosis and intervention has positively impacted outcomes in acute myocardial infarction, stroke, and trauma through elucidating the early pathogenesis of those diseases. This insight may partly explain the futility of time-insensitive immunotherapy trials for severe sepsis and septic shock. The aim of this study was to examine the early natural history of circulatory biomarker activity in sepsis, relative to previous animal and human outcome trials. We conducted a literature search using PubMed, MEDLINE, and Google Scholar to identify outcome trials targeting biomarkers with emphasis on the timing of therapy. These findings were compared with the biomarker activity observed over the first 72 h of hospital presentation in a cohort of severe sepsis and septic shock patients. Biomarker levels in animal and human research models are elevated within 30 min after exposure to an inflammatory septic stimulus. Consistent with these findings, the biomarker cascade is activated at the most proximal point of hospital presentation in our patient cohort. These circulatory biomarkers overlap; some have bimodal patterns and generally peak between 3 and 36 h while diminishing over the subsequent 72 h of observation. When this is taken into account, prior outcome immunotherapy trials have generally enrolled patients after peak circulatory biomarker concentrations. In previous immunotherapy sepsis trials, intervention was delayed after the optimal window of peak biomarker activity. As a result, future studies need to recalibrate the timing of enrollment and administration of immunotherapy agents that still may hold great promise for this deadly disease.

Proinflammatory versus anti-inflammatory response in sepsis patients: looking at the cytokines

Critical Care, 2014

Introduction: During the course of systemic inflammation, most of the immune cell types get activated to a certain degree as part of, or contributing to, the cascade of physiopathological events. Whether for some cells, classically phagocytes of the innate immune system, it is clear that direct sensing of pathogen-associated molecular patterns leads to activation initiating systemic inflammation, the picture is not so clear for natural killer (NK) cells. While NK cells have been shown to express toll-like receptors (TLR), the role of these receptors on NKs during systemic inflammation has not been directly addressed. Methods: To directly assess the role of TLR expression on NK cells we used an adoptive transfer model in which NKs purified from the spleens of WT, TLR4KO and TLR2/4DKO mice were transferred intravenously to RAG2 -/γc -/-(devoid of T, B and NK cells). Five days after reconstitution the mice were challenged intraperitoneally with conventional or TLR-grade lipopolysaccharide (LPS). Immune cell activation and production of IFNγ by NK cells was determined after 6 hours by FACS analysis. Results: We observed no differences in reconstitution of the recipient mice with NK cells from different backgrounds suggesting no difference in trafficking and survival of the transferred cells. At 6 hours after LPS challenge, WT, TLR4KO or TLR2/4DKO NK cells recovered from the spleen and lungs of RAG2 -/γc -/mice showed comparable levels of CD69 activation marker expression. Intracellular labeling for IFNγ in NK cells also revealed no significant differences. Conclusion: Whether there is a role for direct TLR signaling on NK cells remains the objective of further investigations; however, our data show that in the course of a systemic inflammatory process, like endotoxinemia, the expression of TLR2 and TLR4 by NK cells makes no difference in terms of their activation and secretion of IFNγ