Protein C as an early biomarker to distinguish pneumonia from sepsis

Purpose

Patients with pneumonia often are unrecognized as also having sepsis. We evaluated protein C, as a potential biomarker, to differentiate between patients with pneumonia and sepsis.

Materials and Methods

A retrospective chart review was performed for all protein C tests over a 14-month period (January 11, 2007, to March 10, 2008) at an 8-hospital system with 1706 total beds. Charts were screened for the discharge diagnoses of sepsis, severe sepsis, septic shock, bacteremia, and pneumonia. Protein C levels were compared between patients with sepsis and pneumonia, and at time intervals of 0 to 12 hours, 12 to 24 hours, 24 to 48 hours, and more than 48 hours after diagnosis.

Results

One thousand forty-seven protein C levels were obtained in 980 patients. Thirty-two protein C levels met the inclusion and exclusion criteria for the sepsis group, and 34 for the pneumonia group. Overall, the mean protein C levels were significantly less in patients with sepsis at 59.2% (95% confidence interval [CI], 49.5%-68.9%) compared with patients with pneumonia at 108.9% (95% CI, 95.6%-122.3%; P < .001). In addition, levels within each of the time intervals were also significantly lower in the sepsis group.

Conclusions

In this study, protein C levels performed well in differentiating between patients with sepsis or pneumonia in the early period after diagnosis.     

乌司他丁对肠源性脓毒症大鼠D-二聚体和蛋白C系统的影响

目的：观察乌司他丁（ulinastatin，UTI）对肠源性脓毒症大鼠D-二聚体（DD）、蛋白C（PS）系统的影响。方法：将Wistar大鼠随机分为4组，假手术组（SH组，n=36）、脓毒症组（SEP组，n=30）、UTI3h给药组（UTI3h组。n=30）和12h给药组（UTI12h组，n=18）。利用经典盲肠结扎穿孔法建立肠源性脓毒症大鼠模型，分别于正常对照组及制模后6、12、24、48及72h组心脏取血测定DD、PC和蛋白S（PS）。结果：与SH组相比，SEP组大鼠DD在造模后逐渐升高，PC、PS含量降低，差异有显著性（P〈0．05）。与SEP组相比，UTI3h,UTI12h组大鼠的DD降低，PC含量下降趋势减弱，差异有显著性（P〈0．05）。结论：UTI能有效改善脓毒症期间的抗凝抑制和继发性纤溶亢进。     

脓毒症与内皮细胞损伤

脓毒症的发病率和死亡率一直居世界首位。内皮细胞损伤导致多器官功能障碍增加了脓毒症的严重程度和死亡风险。在这篇综述中,我们阐述了内皮细胞在正常生理条件下的功能和在脓毒症时的功能变化,其中包括内皮细胞形态学的改变,内皮细胞促粘附、促凝、抗纤溶的功能改变和降低了对血管张力的调节。内皮细胞可能成为我们治疗脓毒症的靶点。     

狼疮抗凝物抑制蛋白C途径引起血栓的机制研究

目的 从狼疮抗凝物（LA）抑制蛋白C（PC）途径研究系统性红斑狼疮（SLE）患者发生血栓的机制。方法 依整磷脂酰乙醇胺（PE）活化的蛋白C（APC）活性抑制试验（改良的dRVVT方法）,将正常人与SLE患者IgG预先与PE孵育后再加入纯化的试验体系中,观察是否抑制APC活性。结果 试验体系中APC的抗凝活性由于加入PE而增强。LA可抑制依赖PE的APC抗凝活性;且与其浓度成正比。SLE伴LA阳性的血栓患者的LA－IgG对APC抑制程度比LA阴性及无血栓的SLE患者更明显;而正常人IgG对APC无抑制作用。结论 LA通过干扰PE抑制PC途径可能SLE患者发生血栓的重要原因。     

Protein C pathway in sepsis

The goals of this chapter are to provide a brief review of the biology of the protein C pathway and some of the features of the pathway that make it uniquely positioned to control microvascular coagulation and control the acute inflammatory response. Activated protein C works as an antithrombotic agent by inactivating factors Va and VIIIa. It is particularly effective at preventing microvascular thrombosis. Platelets may provide a margin of safety for activated protein C as an antithrombotic. Approximately 25% of the factor V/Va in plasma is contained within the platelet and hence resistant to time dependent inactivation by activated protein C. In addition, factor Va bound to the platelet surface is relatively resistant to inactivation by activated protein C. Activated protein C also facilitates clot lysis by inhibiting plasminogen activator inhibitor 1, a process that is accelerated markedly by vitronectin. Inflammatory cytokines like tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) downregulate two key components of the protein C activation complex, thrombomodulin and the endothelial cell protein C receptor resulting in decreased protein C activation. Activated protein C in turn has been shown in several animal models and in vitro to inhibit TNF elaboration in response to endotoxin. This inhibition appears to be due to diminished nuclear factor kappaB (NF kappaB) expression and nuclear translocation. Activated protein C has been shown to reduce the rate of death due to severe sepsis. This reduction may be due to both the anticoagulant effects as demonstrated by a reduction in D-dimer and inflammatory effects as demonstrated by a reduction in interleukin 6.     

Anticoagulant modulation of inflammation in severe sepsis

Inflammation and coagulation are so tightly linked that the cytokine storm which accompanies the development of sepsis initiates thrombin activation and the development of an intravascular coagulopathy. This review examines the interaction between the inflammatory and coagulation cascades, as well as the role of endogenous anticoagulants in regulating this interaction and dampening the activity of both pathways. Clinical trials attempting to improve outcomes in patients with severe sepsis by inhibiting thrombin generation with heparin and or endogenous anticoagulants are reviewed. In general, these trials have failed to demonstrate that anticoagulant therapy is associated with improvement in mortality or morbidity. While it is possible that selective patients who are severelyill with a high expected mortality may be shown to benefit from such therapy, at the present time none of these anticoagulants are neither approved nor can they be recommended for the treatment of sepsis.     

Protein C concentrate to restore physiological values in adult septic patients

OBJECTIVE: To describe the efficacy and safety of protein C (PC) concentrate to restore physiological values in adult septic patients having clinical contraindications to activated PC. DESIGN: Case series (pilot study). SETTING: Three adult ICUs of a University Hospital. PATIENTS AND PARTICIPANTS: Twenty adult patients affected by severe sepsis or septic shock with plasma values of PC < 50%. INTERVENTIONS: Patients were treated with PC concentrate (Ceprotin ((R))--Baxter) with a starting bolus followed by a continuous infusion for 72 h [3 IU/(kg h)]. MEASUREMENTS AND RESULTS: PC activity, WBC, platelets, D: -Dimer, fibrinogen, PT, aPTT, AT III, lactate, Sepsis-related Organ Failure Assessment (SOFA), Disseminated Intravascular Coagulation (DIC) score, adverse events, and mortality were measured. Baseline plasma PC activity was 34.5 +/- 9.1%. PC concentrate normalized the PC activity in all patients within 48 h, and then remained stable for the following days. At baseline, several patients showed abnormal PT, aPTT, platelets values, and lactate levels. During the study period, there was a significant increase of platelets, fibrinogen, PT, AT III, and a significant decrease of D: -Dimer, aPTT, DIC score, and lactate. No adverse reactions (hemorrhage or thrombosis) were observed. Mortality at 28 days was 35%. CONCLUSIONS: Our pilot study shows that the administration of PC concentrate to patients having contraindications to the treatment with activated PC was safe and possibly useful to control the coagulopathy triggered and sustained by sepsis. A randomized, double blind study in patients with severe sepsis and contraindications to activated PC administration would be advisable to state the safety and the possible role of this product in the treatment of severe sepsis.     

维生素C在脓毒症中的应用进展

脓毒症是重症患者发病和死亡的主要原因。由于氧化应激时代谢消耗增加以及脱氢抗坏血酸再循环减少等原因,脓毒症患者常合并维生素C减少或缺乏。外源性补充维生素C,可能是脓毒症有效的辅助治疗措施。本文就维生素C在脓毒症中应用的作用机制、用法用量、潜在副作用、联合疗法及目前开展的临床研究等方面进行综述,旨在深化临床医师对维生素C在脓毒症治疗中的作用的认识。     

内皮细胞蛋白C受体与脓毒症的研究进展

内皮细胞蛋白C受体(EPCR)是蛋白C抗凝系统的主要组成部分.EPCR不仅在蛋白C活化过程中起重要作用,而且作为蛋白C及活化蛋白C的共同受体,EPCR在脓毒症中亦介导了活化蛋白C抗炎及细胞保护作用的发挥.本文就EPCR的结构、表达调节及其在脓毒症中的作用作一综述.     

Coagulopathy,catecholamines, and biomarkers of endothelial damage in experimental human endotoxemia and in patients with severe sepsis: A prospective study

Purpose

The aim of this study was to investigate associations between circulating catecholamines, endothelial damage, and coagulopathy in experimental human endotoxemia and septic patients.

Materials and Methods

Nine healthy male volunteers undergoing endotoxemia (4-hour 0.5 ng/kg/hour infusion of E. coli lipopolysaccharide, blood sampling at 0, 4, and 6 hours) and 20 patients with severe sepsis. Analysis of plasma biomarkers (adrenaline, noradrenaline, thrombomodulin, syndecan-1, soluble vascular endothelial cadherin, histone-complexed DNA fragments, soluble CD40 ligand [sCD40L], protein C, tissue-type plasminogen activator, plasminogen activator inhibitor 1) and routine coagulation tests.

Results

Endotoxemia increased heart rate, temperature, white blood cell count, C-reactive protein and procalcitonin, decreased blood pressure and induced a hemostatic response with platelet consumption, reduced protein C and sCD40L levels and enhanced tissue-type plasminogen activator release (all P < .05). Septic patients had increased levels of noradrenaline, syndecan-1, thrombomodulin, histone-complexed DNA and sCD40L but reduced soluble vascular endothelial cadherin and plasminogen activator inhibitor 1 (all P < .05) and plasma catecholamines correlated positively with syndecan-1 (adrenaline and noradrenaline) and sTM (only noradrenaline) (all P < .05), biomarkers reflecting endothelial damage. Furthermore, noradrenaline, syndecan-1 and thrombomodulin levels correlated with INR and disease severity scores (noradrenaline and thrombomodulin) (all P < .05).

Conclusions

Experimental endotoxemia induced a discrete hemostatic response without sympathoadrenal activation or endothelial damage. Septic patients had high levels of catecholamines and endothelial damage biomarkers that correlated with each other and with markers of hypocoagulability and disease severity.     

Relationship of antibodies to endotoxin core to mortality in medical patients with sepsis syndrome

Objectives: To assess the prognostic value of determining anti-endotoxin core antibodies (EndoCab) immunoglobulin (Ig)G and IgM in medical patients with sepsis syndrome in order to identify patient subgroups that may profit from endotoxin-neutralizing therapy. The findings were correlated with clinical outcome, endotoxin levels and sepsis score. Design: Cohort study with a follow-up period of 30 days. Setting: Medical intensive care units (2) of a university hospital. Patients and methods: Twenty-nine patients who fulfilled the criteria of sepsis syndrome and did not present with septic shock or had not been treated with antibiotics for more than 3 days were included in the study. Twenty-one intensive care patients without infections served as controls for antibody concentrations. Interventions: Blood samples were obtained from indwelling arterial catheters or direct venipuncture on admission and daily thereafter until transfer to a regular unit. Sepsis scores were determined daily. Results: The mortality rate at 30 days was 44.8 % (13 out of 29). Sepsis patients had significantly lower initial EndoCab IgM and IgG concentrations than controls. Initial EndoCab IgG concentrations were significantly lower in non-survivors of sepsis syndrome but not in survivors compared to controls (median concentrations 51.5 vs 110.1 vs 245.4 MU/ml). EndoCab IgM and IgG were lower in non-survivors compared to survivors, though that difference failed to reach significance (p = 0.11 in both cases). Depletion of initial EndoCab IgM concentrations (defined as a value below the 10th percentile of a control population) was present in 15 patients, 9 of whom died, and depletion of IgG in five patients, four of whom died. EndoCab IgM and IgG concentrations rose concordantly in survivors and non-survivors in the course of the disease. Endotoxin levels were significantly higher in non-survivors compared to controls but not in survivors. A sepsis score of 21 and higher was associated with 90.9 % mortality (specificity 93.8 %, sensitivity 76.9 %). Conclusions: Decreased EndoCab IgG concentrations are associated with increased mortality in medical patients with sepsis syndrome. The measurement of initial anti-endotoxin antibodies may provide a useful tool to identify septic patients who profit potentially from endotoxin neutralizing therapy, however considerable overlap of antibody concentrations warrants additional parameters. The sepsis score is easy to determine and useful in the evaluation of medical patients with sepsis. Received: 4 September 1998 Final revision received: 28 December 1998 Accepted: 15 February 1999     

2型糖尿病病人血浆可溶性内皮细胞蛋白C受体和血栓调节蛋白的变化

目的 探讨2型糖尿病(2-DM)病人血浆可溶性内皮细胞蛋白C受体(sEPCR)和血栓调节蛋白(sTM)的测定及其临床意义。方法 采用酶联免疫双抗体夹心法测定74例2-DM病人和20例正常对照组(C组)sEPCR和sTM,并根据24 h尿白蛋白(24 h UAE)分为A组(n=36,24 h UAE<30 mg)、B组(n=18,24 h UAE<30～300 mg)和C组(n=20,24 h UAE≥300 mg)。结果 与C组比较,DM病人血浆sEPCR和、sTM显著升高,P<0.05和P<0.01;分组比较,A组sEPCR和sTM水平无显著差异,B组显著升高(P<0.05和P<0.01),C组更进一步升高,P值分别<0.01和0.001;sEPCR与sTM、24 h UAE和糖化血红蛋白呈显著正相关(P<0.05),sTM与24 h UAE(P<0.01)和糖化血红蛋白(P<0.05)呈显著正相关;sEPCR和sTM与DM病程、空腹血糖、血脂和年龄均无相关性。结论 sEPCR和sTM升高与DM血管病变的发生和严重程度相关,是反映血管内皮细胞功能的良好指标,并可能参与其高凝状态的形成。     

Impairment of thrombin generation in the early phases of the host response of sepsis

Purpose

The purpose was to investigate the presence of hypercoagulability in the very early phase of the host response to an infection in the clinical course of sepsis and septic shock.

Material and Methods

Twenty-four patients with chemotherapy-associated febrile neutropenia were evaluated at baseline, at the time of fever onset, and 48 hours thereafter using the thrombin generation test, a more physiological and global assay of hemostasis.

Results

The rate of thrombin generation was decreased and no signals of systemic hypercoagulability could be observed during the first 48 hours of sepsis. Moreover, patients that evolved to septic shock presented a more significant impairment in thrombin generation than those with noncomplicated sepsis.

Conclusions

Patients with sepsis and febrile neutropenia present an impairment in thrombin generation from very early stages of their disease course. These results suggest that the procoagulant in vitro alterations described during sepsis do not necessarily translate into a clinically relevant systemic hypercoagulable state. These findings could help explain why treatment with systemic anticoagulants did not translate to clinical benefits in human sepsis and highlight the need for a better understanding of the hemostatic alterations in sepsis before new treatments targeting coagulation activation are developed.     

凝血酶对牛主动脉内皮细胞组织因子活性的影响及其与PKC传导途径的关系

目的探讨凝血酶对内皮细胞组织因子（ＴＦ）活性的刺激作用及其与细胞内蛋白激酶Ｃ（ＰＫＣ）传导系统的关系。方法传代培养新生牛主动脉血管内皮细胞,取刺激或未受刺激的第４～８代细胞冻融液测定其ＴＦ活性。结果体外培养的血管内皮细胞在静息状态下ＴＦ活性极低（４．２０±１．１９）。与对照组相比,凝血酶的刺激使内皮细胞ＴＦ活性明显升高（ｎ＝８,Ｐ＜０．００１）,且呈剂量依赖性关系（ｒ＝０．７８,Ｐ＜０．０５）和时间依赖性关系（ｒ＝０．８８,Ｐ＜０．０５）。ＰＫＣ抑制剂Ｈ７抑制凝血酶对内皮细胞ＴＦ活性的刺激作用（ｎ＝８,Ｐ＜０．０１）,且抑制作用呈剂量依赖性。ＰＫＣ激动剂佛波酯也可刺激内皮细胞ＴＦ活性增高（３０．５９±３．７９,ｎ＝８,Ｐ＜０．００１）,并可被Ｈ７阻断,ＰＭＡ对凝血酶的刺激作用没有显著影响。结论在凝血酶的刺激下,血管内皮细胞可产生较大量的ＴＦ;凝血酶对内皮细胞的这种刺激作用依赖于细胞内ＰＫＣ系统传导途径。     

抗磷脂综合征合并静脉血栓和蛋白C活性异常1例研究报告

目的：探讨抗磷脂综合征（antiphospholipid syndrome，APS）患者静脉血栓形成的原因。方法：对1例APS患者用发色底物法测定蛋白C活性（PC：A）、蛋白S活性（PS：A）和抗凝血酶活性；用ELISA方法测定PC、血浆纤溶酶原、血浆组织型纤溶酶原激活物、血浆纤溶酶原激活抑制物-1、α2-抗纤溶酶抗原和抗心磷脂抗体（ACA）。活化蛋白C抵抗（APC—R）检测结果以受检者血浆加入APC后的APTT与未加APC血浆的APTT的比值表示，比值〈2．0时为APC-R阳性。狼疮抗凝物质（LA）检测使用以dRVVT为基础的商品化试剂盒。采用PCR扩增和直接测序，检测PC的基因及FVLeiden和凝血酶原G20210A的突变。结果：本例患者LA和APC—R阳性，PC：A降低，PC抗原量增加，其他结果正常．PC基因所有外显子测字结果正常，FVLeiden突变和凝血酶原G20210A突变未检出。结论：LA可能通过抑制PC途径导致患者发生血栓，联合检测ACA、APC-R、抗凝蛋白抗原及活性有利于血栓性疾病的病因学诊断。     

糖尿病足患者血浆活化蛋白C抵抗、蛋白C和蛋白S活性的测定

目的探讨PC、PS活性的变化在糖尿病足形成中的作用和临床意义,以及APCR与糖尿病足形成的关系。方法采用Dahlback法对50例健康成年人(对照组)及60例糖尿病足患者(DF1、DF2组)进行APCR阳性率测定,同时测定受检者蛋白C(PC,)和蛋白S(PS)。结果糖尿病足(DF)患者血浆PC/PS活性下降与对照组有显著性差异。结论血浆PC/PS活性检测对糖尿病足患者的诊断、估计预后和疗效观察有参考价值,且APCR阳性者有动脉血栓发生的倾向。     

IL-35和C3与脓毒症患者病情严重程度及预后的关系

目的 探讨补体C3和白细胞介素35(IL-35)在脓毒症病情判断及预后评估中的价值.方法 选取脓毒症患者80例,其中脓毒症45例(脓毒症组)、严重脓毒症患者35例(严重脓毒症组)[单器官功能障碍12例(单器官功能障碍组)、多器官功能障碍综合征(MODS)16例(MODS组)、死亡7例(死亡组)],收集所有患者的临床资料...