Temporal increase of platelet mitochondrial respiration is negatively associated with clinical outcome in patients with sepsis

Introduction  

Mitochondrial dysfunction has been suggested as a contributing factor to the pathogenesis of sepsis-induced multiple organ failure. Also, restoration of mitochondrial function, known as mitochondrial biogenesis, has been implicated as a key factor for the recovery of organ function in patients with sepsis. Here we investigated temporal changes in platelet mitochondrial respiratory function in patients with sepsis during the first week after disease onset.     

白介素10基因多态性与术后脓毒症发生发展的相关研究

目的研究白介素10（IL-10）基因启动子区域中IL-10-592、IL-10-819、IL-101-082基因多态性与术后严重脓毒症易感性及其预后的相关性。方法采用聚合酶链反应（PCR）结合RsaⅠ、MaeⅢ、MnlⅠ限制性内切酶酶切分析法检测116例术后并发严重脓毒症患者和141例健康献血员（对照组）的IL-10-592、IL-10-819、IL-10-1082基因多态性。结果IL-10-1082等位基因1的频率在脓毒症组为59.9％,对照组为50.4%（P<0.05）;IL-10-1082基因型分布频率在脓毒症组和对照组间有显著性差异（P<0.05）;而IL-10-592、IL-10-819等位基因频率及基因型频率在脓毒症组和对照组间均无显著性差异（P均>0.05）;IL-10-592、IL-10-819、IL-10-1082等位基因频率及基因型频率在死亡的与存活的脓毒症患者间均无显著性差异（P均>0.05）。结论IL-10-1082基因多态性与术后严重脓毒症的易感性有关,与其预后不相关;而IL-10-592、IL-10-819基因多态性与术后严重脓毒症的易感性及预后均不相关。     

Cytomegalovirus reactivation and associated outcome of critically ill patients with severe sepsis

Introduction

Sepsis has been identified as a risk factor for human cytomegalovirus (CMV) reactivation in critically ill patients. However, the contribution of CMV reactivation on morbidity and mortality is still controversial. Therefore, we analyzed the incidence and impact of CMV reactivation on outcome in patients with severe sepsis.

Methods

In a prospective longitudinal double-blinded observational study, 97 adult nonimmunosuppressed CMV-seropositive patients with new onset of severe sepsis were included. Leukocytes, plasma and tracheal secretions were examined weekly for CMV-DNA by PCR. Tracheal secretions were additionally tested for HSV (Herpes Simplex Virus)-DNA. The influence of CMV-reactivation on the endpoints was analysed by Cox proportional-hazard regression analysis. Time-dependency was evaluated by landmark analysis.

Results

Six out 97 died and five were discharged from the hospital within 72 hours and were excluded of the analysis. CMV reactivation occurred in 35 of the 86 (40.69%) analysed patients. HSV infection occurred in 23 of the 35 (65.7%) CMV reactivators. In 10 patients CMV-plasma-DNAemia appeared with a DNA-content below 600 copies/ml in four cases and a peak amount of 2,830 copies/ml on average. In patients with and without CMV reactivation mortality rates were similar (37.1% vs. 35.3%, P = 0.861), respectively. However, in the multivariate COX regression analyses CMV reactivation was independently associated with increased length of stay in the ICU (30.0, interquartile range 14 to 48 vs. 12.0, interquartile range 7 to 19 days; HR (hazard ratio) 3.365; 95% CI (confidence interval) 1.233 to 9.183, P = 0.018) and in the hospital (33.0, interquartile range 24 to 62 vs. 16.0, interquartile range 10 to 24 days, HR 3.3, 95% CI 1.78 to 6.25, P < 0.001) as well as prolonged mechanical ventilation (22.0, interquartile range 6 to 36 vs. 7.5, interquartile range 5 to 15.5 days; HR 2.6,CI 95% 1.39 to 4.94; P < 0.001) and impaired pulmonary gas exchange (six days, interquartile range 1 to 17, vs. three, interquartile range 1 to 7, days in reactivators vs. non-reactivators, P = 0.038). HSV reactivation proved not to be a risk factor for these adverse effects.

Conclusions

These data indicate an independent correlation between CMV reactivation and increased morbidity in the well-defined group of nonimmunosuppressed patients with severe sepsis, but CMV reactivation had no impact on mortality in this group with low CMV-DNA plasma levels. Thus, the potential harms and benefits of antiviral treatment have to be weighed cautiously in patients with severe sepsis or septic shock.     

Early lactate clearance is associated with improved outcome in severe sepsis and septic shock

OBJECTIVE: Serial lactate concentrations can be used to examine disease severity in the intensive care unit. This study examines the clinical utility of the lactate clearance before intensive care unit admission (during the most proximal period of disease presentation) as an indicator of outcome in severe sepsis and septic shock. We hypothesize that a high lactate clearance in 6 hrs is associated with decreased mortality rate. DESIGN: Prospective observational study. SETTING: An urban emergency department and intensive care unit over a 1-yr period. PATIENTS: A convenience cohort of patients with severe sepsis or septic shock. INTERVENTIONS: Therapy was initiated in the emergency department and continued in the intensive care unit, including central venous and arterial catheterization, antibiotics, fluid resuscitation, mechanical ventilation, vasopressors, and inotropes when appropriate. MEASUREMENTS AND MAIN RESULTS: Vital signs, laboratory values, and Acute Physiology and Chronic Health Evaluation (APACHE) II score were obtained at hour 0 (emergency department presentation), hour 6, and over the first 72 hrs of hospitalization. Therapy given in the emergency department and intensive care unit was recorded. Lactate clearance was defined as the percent decrease in lactate from emergency department presentation to hour 6. Logistic regression analysis was performed to determine independent variables associated with mortality. One hundred and eleven patients were enrolled with mean age 64.9 +/- 16.7 yrs, emergency department length of stay 6.3 +/- 3.2 hrs, and overall in-hospital mortality rate 42.3%. Baseline APACHE II score was 20.2 +/- 6.8 and lactate 6.9 +/- 4.6 mmol/L. Survivors compared with nonsurvivors had a lactate clearance of 38.1 +/- 34.6 vs. 12.0 +/- 51.6%, respectively (p =.005). Multivariate logistic regression analysis of statistically significant univariate variables showed lactate clearance to have a significant inverse relationship with mortality (p =.04). There was an approximately 11% decrease likelihood of mortality for each 10% increase in lactate clearance. Patients with a lactate clearance> or =10%, relative to patients with a lactate clearance <10%, had a greater decrease in APACHE II score over the 72-hr study period and a lower 60-day mortality rate (p =.007). CONCLUSIONS: Lactate clearance early in the hospital course may indicate a resolution of global tissue hypoxia and is associated with decreased mortality rate. Patients with higher lactate clearance after 6 hrs of emergency department intervention have improved outcome compared with those with lower lactate clearance.     

APOE polymorphism is associated with risk of severe sepsis in surgical patients

OBJECTIVE: To test for an association between apolipoprotein E (APOE) genotypes and the occurrence of severe sepsis in an elective surgical cohort. DESIGN: Prospective, observational, single cohort study. SETTING: Sixteen-bed surgical intensive care unit (ICU) at a university hospital. PATIENTS: Patients were 343 patients with planned admission to the ICU after major elective noncardiac surgery. INTERVENTIONS: Blood samples, together with demographic data, baseline clinical data, and Acute Physiology and Chronic Health Evaluation II scores, were collected on admission to the ICU and on each subsequent ICU day. APOE genotyping was conducted using a polymerase chain reaction-based assay. The primary outcome was diagnosis of severe sepsis; secondary outcomes included time on mechanical ventilation, ICU length of stay, and ICU mortality. MEASUREMENTS AND MAIN RESULTS: Severe sepsis was diagnosed in 34 of 343 patients (9.9%). Carriers of the APOepsilon3 allele (one or two copies) had a lower incidence of severe sepsis than patients with no APOepsilon3 allele (p = .014), with a relative risk of 0.284 (95% confidence interval 0.127-0.635). The protective effect of APOepsilon3 genotype on the incidence of severe sepsis remained significant (p < .01) after adjusting for age, gender, or race in a logistic regression model. Supporting our findings, presence of the APOepsilon3 allele was also associated with fewer days spent in the ICU (p = .007). In contrast, APOE genotypes were not associated with duration of mechanical ventilation or ICU mortality. CONCLUSIONS: In an elective surgical cohort, presence of the APOepsilon3 allele is associated with decreased incidence of severe sepsis and a shorter ICU length of stay.     

A CXCL2 polymorphism is associated with better outcomes in patients with severe sepsis

OBJECTIVE: Several studies have implicated the CXCL2 chemokine as a mediator in the development of sepsis. We hypothesized that a tandem repeat polymorphism (AC)n in the CXCL2 gene, previously associated with susceptibility to severe sepsis, contributes to morbidity and mortality in severe sepsis. DESIGN: Prospective, observational, genetic study of septic patients. SETTING: A network of Spanish postsurgical and critical care units. PATIENTS: A total of 183 critically ill patients fulfilling the International Sepsis Criteria for severe sepsis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients were classified into three groups according to the presence of compound 24 +/- 1 (AC) repeat genotypes: homozygote 24 +/- 1 carriers (HC group), heterozygote 24 +/- 1 carriers (HTC), and non 24 +/- 1 carriers (NC group). Mortality, development of acute respiratory distress syndrome, and number of failing organs were determined for each group. Overall mortality was 46.4%. HC patients had a lower mortality (39.9%) than HTC (52.2%) and NC (72.7%) patients (trend test p = .018). This difference remained significant when using a multiple logistic regression analysis (p = .035). The presence of population stratification was ruled out, since 20 independent genomic control markers demonstrated homogeneity among groups. An exploratory analysis of the effect of acute respiratory distress syndrome on mortality showed a relative risk of 2.60 in the HC group (p = .0004), while in the nonhomozygote carriers (NHC) group the relative risk was 3.34 (p = .0001). CONCLUSIONS: Our data suggest that a tandem repeat polymorphism (AC)n at position -665 in the CXCL2 gene may be an independent predictor of mortality for severe sepsis. Additional studies are needed to confirm these results.     

Severe protein C deficiency is associated with organ dysfunction in patients with severe sepsis

PurposeThe aim of this study was to assess the relationship between protein C levels and temporal changes in organ dysfunction.Materials and MethodsUsing data from the placebo arm of Recombinant Human Activated PROtein C Worldwide Evaluation in Severe Sepsis trial (N = 775), we compared the development of organ dysfunction over time, in adult severe sepsis patients with and without severe protein C deficiency.ResultsAt study enrollment (baseline), patients with and without severe protein C deficiency were similar in age and likelihood of comorbidities. Patients with severe protein C deficiency had lower arterial blood pressure (P = .0006), greater serum creatinine concentration (P < .0001), elevated markers of thrombosis and inflammation, and impairment of fibrinolysis (P < .0001). The baseline PaO₂/FiO₂ ratio was not significantly different between the 2 groups. Seven days after study enrollment, cardiovascular and renal function remained significantly worse in patients with severe protein C deficiency (P < .0001), and respiratory dysfunction was greater (P < .0001). Baseline protein C deficiency was seen to be associated with subsequent pulmonary, renal, and hematologic organ failure.ConclusionsSevere protein C deficiency in patients with severe sepsis is associated with both the incidence and severity of organ dysfunction and subsequent worsening of organ function and may be a useful predictor of organ failure in severe sepsis.     

严重脓毒症患者血清血管内皮生长因子的临床研究

目的 检测严重脓毒症患者血清血管内皮生长因子(VEGF)水平的动态变化,探讨VEGF与急性生理学与慢性健康状况评分系统Ⅱ(APACHEⅡ)评分及相关临床参数的关系.方法 采用前瞻性随机对照研究,选择2006年7月-2007年10月本院重症监护病房(ICU)收治的29例严重脓毒症患者,检测发病后1、3、7 d血小板计数(PLT)、白蛋白(Alb)水平,并计算APACHEⅡ评分;采用酶联免疫吸附法(ELISA)检测血清VEGF水平,并按患者生存与死亡分为两组,比较两组的异同.以同期31例健康体检者作为健康对照组.结果 健康对照组VEGF水平为(78.77±8.15)ng/L;生存组16例患者随时间延长VEGF水平逐渐下降(F=40.32,P<0.01),7 d时接近健康对照组(P>0.05);死亡组13例患者VEGF水平3 d下降,7 d又上升(F=29.61,P<0.01).VEGF水平与APACHEⅡ评分呈显著正相关(r=0.510,P=0.000),与PLT呈显著负相关(r=-0.221,P=0.046),与Alb未显示相关性(r=-0.029,P=0.789).结论 严重脓毒症患者VEGF水平在发病早期明显升高,随病程进展生存组VEGF水平逐渐下降,死亡组下降不明显,VEGF在一定程度上反映脓毒症病情严重程度.     

Serum lipid profile,cytokine production,and clinical outcome in patients with severe sepsis

Purpose

The purpose of the study is to evaluate the prevalence and clinical significance of hypolipidemia and the relationship to cytokine concentrations and outcomes in septic patients.

Materials and methods

A prospective study was undertaken including 50 patients with severe sepsis due to community-acquired infections. Serum concentrations of total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein as well as tumor necrosis factor α (TNF-α), interleukin (IL) 6, IL-8, IL-10, and transforming growth factor (TGF) β₁ were determined on admission and days 3 and 10 during hospitalization.

Results

Of the 50 patients enrolled, 28 survived, whereas 22 died during their hospital stay. Sepsis survivors had significantly higher HDL-C concentrations than nonsurvivors, whereas all patients with HDL-C values greater than 25 mg/dL survived. Baseline levels of TGF-β₁ were significantly higher in survivors. High-density lipoprotein levels correlated inversely with TNF-α, IL-6, and IL-10 concentrations and positively with baseline TGF-β₁ levels. Independent risk factors of mortality were IL-10 levels on day 3, whereas HDL-C concentration on admission was related to survival.

Conclusions

Low cholesterol and lipoprotein concentrations are detected in septic patients, especially in individuals with poor outcome. High-density lipoprotein cholesterol concentration seems to be an early independent predictive marker of survival in severe sepsis.     

Masseter muscle oxygen saturation is associated with central venous oxygen saturation in patients with severe sepsis

Objective  

This monocentric prospective study was conducted to determine if tissue oxygen saturation measured non invasively over masseter muscle site (Masseter-StO2) can predict the central venous oxygen saturation (ScvO2) level in severe sepsis and septic shock.     

De-escalation of empirical therapy is associated with lower mortality in patients with severe sepsis and septic shock

Purposes

We set out to assess the safety and the impact on in-hospital and 90-day mortality of antibiotic de-escalation in patients admitted to the ICU with severe sepsis or septic shock.

Methods

We carried out a prospective observational study enrolling patients admitted to the ICU with severe sepsis or septic shock. De-escalation was defined as discontinuation of an antimicrobial agent or change of antibiotic to one with a narrower spectrum once culture results were available. To control for confounding variables, we performed a conventional regression analysis and a propensity score (PS) adjusted-multivariable analysis.

Results

A total of 712 patients with severe sepsis or septic shock at ICU admission were treated empirically with broad-spectrum antibiotics. Of these, 628 were evaluated (84 died before cultures were available). De-escalation was applied in 219 patients (34.9 %). By multivariate analysis, factors independently associated with in-hospital mortality were septic shock, SOFA score the day of culture results, and inadequate empirical antimicrobial therapy, whereas de-escalation therapy was a protective factor [Odds-Ratio (OR) 0.58; 95 % confidence interval (CI) 0.36–0.93). Analysis of the 403 patients with adequate empirical therapy revealed that the factor associated with mortality was SOFA score on the day of culture results, whereas de-escalation therapy was a protective factor (OR 0.54; 95 % CI 0.33–0.89). The PS-adjusted logistic regression models confirmed that de-escalation therapy was a protective factor in both analyses. De-escalation therapy was also a protective factor for 90-day mortality.

Conclusions

De-escalation therapy for severe sepsis and septic shock is a safe strategy associated with a lower mortality. Efforts to increase the frequency of this strategy are fully justified.     

Macrophage migration inhibitory factor is associated with positive cultures in patients with sepsis after cardiac surgery

This prospective consecutive observational study describes the blood levels of macrophage migration inhibitory factor (MIF), other cytokines, and markers of acute-phase response in 49 consecutive patients who developed the clinical syndrome of sepsis after cardiac surgery. Before starting antimicrobial treatment, all patients underwent microbiologic screening, and blood samples were collected. These samples subsequently were assayed for MIF, macrophage chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6 and -10, procalcitonin (PCT), and C-reactive protein (CRP). Patients with positive cultures (n = 25) had a higher mortality (P = 0.046) and higher levels of MIF (P < 0.001) than those with negative cultures (n = 24). We could not detect significant difference between the groups concerning the levels of CRP, PCT, IL6, IL10, MCP-1, or TNF-alpha. MIF levels showed an area under receiver operator curve of 0.823 for the prediction of culture-proven bacterial infection, with the best cut-off value at 988.5 pg/mL. In conclusion, circulating levels of MIF could be indicated as a valuable marker of microbiologically documented sepsis in patients after cardiac surgery, which suggests that MIF may be prospectively explored as a useful diagnostic tool in this setting.     

重症败血症患者炎性介质水平对预后的影响

探索可早期预测败血症预后的炎性介质指标。方法：前瞻性研究,观察期28日,分析重症败血症患者与死亡相关的临床和实验室指标。结果：共连续观察26例,死亡14例（53．8％）,且多死于研究阶段的第1周内（74．0％）。死亡组患者血总胆红素水平、4项全身炎性反应综合征（SIRS）指标的积分和循环中的细胞间黏附分子－1（sICAM-1)水平明显高于死亡组,其它炎性因子包括一些细胞因子和黏附分子的水平在2组间差异不大。结论：败血症患者的sICAM-1水平可早期预测脏器衰竭和死亡。     

Genetic variants in the NOD2/CARD15 gene are associated with early mortality in sepsis patients

Objective Genetic variants in the NOD2/CARD15 gene resulting in a diminished capacity to activate NF-κB in response to bacterial cell wall products have been associated with Crohn's disease (CD). Recently, we found an association between the variant Leu1007fsinsC of the NOD2/CARD15 gene (SNP13) and a significantly increased rate of transplant related mortality (TRM) due to intestinal and pulmonary complications in stem cell transplantation (SCT). To assess a possible contribution of variants in the NOD2/CARD15 gene to sepsis related mortality (SRM) we investigated 132 prospectively characterised, consecutive patients with sepsis. Design and patients The three most common NOD2/CARD15 variants (Arg702Trp, Gly908Arg, and Leu1007fsinsC) were determined in 132 prospectively characterised patients with sepsis attended to three intensive care units at the University of Regensburg by Taqman PCR. NOD2/CARD15 genotype and major patients' characteristics were correlated with SRM. Results Patient groups with and without NOD2/CARD15 variants did not differ in their clinical characteristics such as median age, gender, reason for admission or APACHE score; however, SRM (day 30) was increased in patients with NOD2/CARD15 coding variants (42 vs. 31%) and was highest (57%) in 8 patients carrying the Leu1007fsinsC variant (p < 0.05). Multivariate analysis demonstrated the Leu1007fsinsC genetic variant as an independent risk factor for SRM. Conclusion Our findings indicate a major role of NOD2/CARD15 coding variants for SRM. This may be indicative for a role of impaired barrier function and bacterial translocation in the pathophysiology of early sepsis related death. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Genetic variants of the MBL2 gene are associated with mortality in pneumococcal sepsis

Studies evaluating associations between polymorphisms of innate immunity genes and prognosis of infectious diseases have yielded conflicting results. Our aim was to assess the impact on mortality of different genotypic variants of the innate immunity in patients with pneumococcal sepsis. All adults admitted to the hospital with diagnosis of sepsis caused by Streptococcus pneumoniae were enrolled and single-nucleotide polymorphisms (SNP) in mannose-binding lectin 2 (MBL2), toll-like receptor (TLR) 2, TLR4, and Fcγ receptor IIa genes were genotyped. Underlying diseases, severity of illness, and antibiotic management were also recorded. We included 117 patients: 98 pneumonias (83.6%), 17 meningitis (14.5%), and 2 patients (1.9%) with primary pneumococcal bacteremia. Allelic variants of the MBL2 gene (individuals heterozygous or homozygous for one of the 3 allelic variants B, C, and D: AO/OO) were present in 37 patients (32%), T399I polymorphism in TLR4 in 19 (16.2%), TLR4 D299G/T399I in 11 (9.4%), TLR2 R753Q in 3 (2.5%), and FcγRIIa-R/R131 in 26 patients (23%). Factors associated independently with in-hospital mortality were SNP MBL2 AO/OO (adjusted hazard ratios [aHR] 3.2, 95% confidence interval [CI] 1.01-9.8) and septic shock (aHR 15.3, 95% CI 3.5-36.5), whereas first adequate antibiotic dose ≤ 4 h was a protective factor (aHR 0.2, 95% CI 0.06-0.8). SNP MBL2 AO/OO (aHR 2.2, 95% CI 1.1-8.1) remained as a variable independently associated with 90-day mortality. In conclusion, variant alleles in the MBL2 gene are independently associated with in-hospital and medium-term mortalities in patients admitted to the hospital with pneumococcal sepsis.     

Increased levels of soluble vascular endothelial cadherin are associated with poor outcome in severe sepsis

Endothelial cells are thought to play a key role in sepsis pathogenesis: vascular endothelial damage occurs in severe sepsis and multiple organ dysfunction. Soluble vascular endothelial cadherin (VE-cadherin) levels were investigated in a prospective study involving 28 consecutive critically ill patients with or without severe sepsis who were admitted to surgical intensive care; 13 healthy age-matched volunteers were included as controls. Soluble VE-cadherin levels increased significantly in patients with severe sepsis compared with ill patients without severe sepsis and healthy controls. There was a significant linear correlation between soluble VE-cadherin levels and illness severity scores. Soluble VE-cadherin levels were significantly higher in patients who died compared with survivors. In vitro cell culture showed that serum from patients with severe sepsis greatly decreased VE-cadherin staining at intercellular junctions and total VE-cadherin expression in human umbilical cord vein endothelial cells. These findings suggest that endothelial cells play an important role in the poor outcome of patients with severe sepsis.