Coagulation biomarkers in critically ill patients

Pharmacotherapy consideration of thrombolytic medications in COVID-19-associated ARDS

BACKGROUND

In late 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is responsible for coronavirus disease (COVID-19), was identified as the new pathogen to lead pneumonia in Wuhan, China, which has spread all over the world and developed into a pandemic. Despite the over 1 year of pandemic, due to the lack of an effective treatment plan, the morbidity and mortality of COVID-19 remains high. Efforts are underway to find the optimal management for this viral disease.

MAIN BODY

SARS-CoV-2 could simultaneously affect multiple organs with variable degrees of severity, from mild to critical disease. Overproduction of pro-inflammatory mediators, exacerbated cellular and humoral immune responses, and coagulopathy such as Pulmonary Intravascular Coagulopathy (PIC) contributes to cell injuries. Considering the pathophysiology of the disease and multiple microthrombi developments in COVID-19, thrombolytic medications seem to play a role in the management of the disease. Beyond the anticoagulation, the exact role of thrombolytic medications in the management of patients with COVID-19-associated acute respiratory distress syndrome (ARDS) is not explicit. This review focuses on current progress in underlying mechanisms of COVID-19-associated pulmonary intravascular coagulopathy, the historical use of thrombolytic drugs in the management of ARDS, and pharmacotherapy considerations of thrombolytic therapy, their possible benefits, and pitfalls in COVID-19-associated ARDS.

CONCLUSIONS

Inhaled or intravenous administration of thrombolytics appears to be a salvage therapy for severe ARDS associated with COVID-19 by prompt attenuation of lung injury. Considering the pathogenesis of COVID-19-related ARDS and mechanism of action of thrombolytic agents, thrombolytics appear attractive options in stable patients without contraindications.

Risk of major bleeding associated with aspirin use in non-surgical critically ill patients receiving therapeutic anticoagulation

BACKGROUND

We aimed to evaluate the risk of major bleeding in non-surgical critically ill patients who received aspirin in conjunction with therapeutic anticoagulation (concomitant therapy) compared to those who received therapeutic anticoagulation alone.

METHODS

This is a retrospective cohort study of critically ill patients initiated on therapeutic anticoagulation at a large academic medical center from 2007 to 2016. The exposure of interest was aspirin therapy during anticoagulation. The primary outcome was the incidence of major bleeding during hospitalization. Secondary outcomes included in-hospital mortality, hospital free days, and new myocardial infarction or stroke.

RESULTS

5507 (73.2%) patients received anticoagulation alone and 2014 (26.8%) received concomitant therapy; major bleeding occurred in 19.0% and 22.2%, respectively. There was no increased risk of major bleeding [OR 1.10 (95% CI: 0.93-1.30); p = .27] or mortality [OR 0.93 (95% CI: 0.77-1.11); p = .43] with concomitant therapy. Patients receiving concomitant therapy had fewer hospital-free days (mean decrease of 0.73 [1.36, 0.09]; p = .03) and were more likely to experience new myocardial infarction or stroke [OR 2.61 (95% CI: 1.72-3.98); p < .001].

CONCLUSIONS

In non-surgical critically ill patients receiving therapeutic anticoagulation, concomitant use of aspirin was not associated with an increased risk of bleeding or in-hospital mortality.

Novel Anticoagulant Peptide from Lactoferrin Binding Thrombin at the Active Site and Exosite-I

Thrombin is currently one of the important targets for the treatment and prevention of thrombosis. At present, there are few reports on the application of lactoferrin peptides in anticoagulation. In this study, a peptide with the amino acid sequence of LRPVAAEIY (LF-LR) derived from lactoferrin was shown to possess antithrombotic activity. LF-LR (5 mM) significantly prolonged activated partial thromboplastin time, prothrombin time, and thrombin time for 13.4, 1.7, and 5.1 s, respectively. It prolonged the coagulation time of fibrinogen from 15.3 ± 0.4 to 20.2 ± 0.5 s by affecting the conformation of thrombin. Using circular dichroism analysis, LF-LR can increase the α-helix content of thrombin from 25.6 to 56.7% and made the β-sheet disappear. In addition, LF-LR also quenched fluorescence of thrombin at about 346 nm (λ_Ex = 280 nm). By means of molecular docking, it was found that LF-LR could bind to both the active site and the exosite-I of thrombin, and the combined LYS60F, TRP60D, ASP189, LYS36, and ARG77A are typical amino acids in the two domains, respectively.

Anticoagulant Decapeptide Interacts with Thrombin at the Active Site and Exosite-I

Thrombin can be used as a target for its inhibitors to prevent blood coagulation. A novel peptide (TKLTEEEKNR, PfCN) identified from αS2-casein (fragments 211-220) with high anticoagulant activity was screened and prepared. The activated partial thromboplastin time, prothrombin time, and thrombin time, at the concentration of 4 mM, prolonged about 19, 2.5 and 5.5 s, respectively. At the same concentration, the fibrinogen clotting time prolonged from 25.5 ± 0.7 to 38.3 ± 1.3 s. The thrombin inhibitory efficiency in vitro (IC₅₀ value of 29.27 mM) and antithrombosis effect in vivo were determined. The secondary structure of thrombin, which was influenced by PfCN, indicates that PfCN can bind to thrombin. Isothermal titration calorimetry and the chromogenic substrate test showed that PfCN belongs to the bivalent thrombin inhibitor like bivalirudin. Although the effect was not as good as bivalirudin, in the animal experiment, bleeding occurred in the bivalirudin group but not in the PfCN group. Moreover, molecular docking illustrates the mechanism for the antithrombin activity of PfCN. These results indicated that PfCN could be used as an effective thrombin inhibitor with broad potential for the prevention of thrombotic acute pulmonary embolism and other thrombotic events.

Prediction of bleeding by thromboelastography in ICU patients with haematological malignancy and severe sepsis

: ICU patients with haematological malignancy have an increased risk of bleeding. Recently, global haemostatic methods such as thromboelastography (TEG) have gained impact in evaluating coagulation. The aim of this study was to observe whether TEG could predict bleeding in haematological ICU patients with severe sepsis. Post-hoc single-centre analysis of patients with haematological malignancy included in the Scandinavian Starch for Severe Sepsis/Septic Shock (6S) trial. Clinical characteristics, TEG measurements and details regarding bleeding complications were retrieved from the 6S database. The association between TEG and bleeding were analysed by Cox regression and receiver operating characteristic curves. A total of 202 patients with severe sepsis were admitted to the ICU of Rigshospitalet, Copenhagen and included in the 6S trial. Forty-one had haematological malignancy and were analysed in the current study. During ICU stay, 20 patients (49%) had bleeding complications and 13 (32%) patients bled within the first 5 ICU days. We observed no associations between TEG and subsequent bleeding in Cox regression models. TEG variables at baseline had low predictive value for bleeding. Baseline TEG variables did not add value in identifying patients with high risk of bleeding in ICU patients with haematological malignancy and severe sepsis.

An anticoagulant peptide from beta-casein: identification, structure and molecular mechanism

A bioactive peptide is identified from casein hydrolysates.

Thromboelastometric prediction of mortality using the kinetics of clot growth in critically ill septic patients

: Sepsis induces alterations in blood coagulation which are associated with mortality. Using rotational thromboelastometry (ROTEM), these states are often characterized by changes in parameters representing terminal clot lysis. However, the ROTEM changes are often subtle, making them difficult to recognize and interpret. The objective of this study is to evaluate a new ROTEM clot velocity parameter representing clot formation kinetics in septic ICU patients. We hypothesized that this time-based parameter was significantly different in critically ill septic survivors vs. nonsurvivors. This retrospective observational study included severe sepsis and septic shock patients having a minimum of two organ dysfunctions by Sequential Organ Failure Assessment criteria (study group), and a control group of healthy adults without infection . ROTEM with EXTEM activation was performed in all groups. The time from maximal clot formation velocity to zero velocity, representing the latter portion of time during active clot formation prior to achieving maximal clot firmness (t-AUCi) was calculated along with other ROTEM parameters and compared between septic survivors, nonsurvivors and healthy controls. A total of 76 septic patients, of which 26.3%, survived, were included in the study group, and 26 healthy control individuals were included in the control group. t-AUCi correlated with terminal clot lysis (P < 0.001), and was significantly prolonged in septic nonsurvivors compared with survivors and healthy controls (P < 0.001). t-AUCi also differentiated nonsurvivors vs. survivors among those patients having similar ROTEM lysis indices. t-AUCi was useful to differentiate critically ill septic patients, and could be useful to identify septic patients with high-risk of ICU mortality.

Effects of malignancy on blood coagulation in septic intensive care patients

: The objectives of the study are to examine the effect of sepsis on the coagulation profile of patients having solid cancer and to test the hypothesis that septic patients with cancer have normal or increased hemostatic capacity despite prolonged standard coagulation tests (SCTs) compared with noninfected cancer patients. Patients with solid cancer were included in the study forming two groups: study group included patients with sepsis with minimum two organ dysfunctions and control group formed by noninfected cancer patients. SCTs, platelet count, plasma levels of coagulation factors and rotation thromboelastometry (TEM International GmbH, Munich, Germany) were determined in both groups. Study group patients (n = 35) showed prolonged SCTs, thrombocytopenia, decreased coagulation factor levels and increased D-dimer compared with control group (n = 35). However, fibrinogen levels and clot firmness assessed by rotation thromboelastometry were not different between groups and clot lysis indexes at 45 and 60 min were increased in study group compared with control group. The first derivative of the clot firmness curve revealed an increased time to the maximum velocity of clot formation for study group, without differences in the maximum velocity of clot formation, or in total thrombus formation. Sepsis with organ dysfunction in cancer patients is associated with delayed initiation of coagulation and reduced fibrinolysis compared with control patients, but overall clot formation and stabilization is not different. For septic cancer patients, SCTs and plasmatic indicators of fibrinolysis do not translate well to whole blood clot formation and may be misleading indicators of thrombotic or bleeding risk.

Thromboelastometry profile in critically ill patients: A single-center, retrospective, observational study

Background

Transfusion therapy is associated with increased morbidity, mortality and costs. Conventional coagulation tests (CCT) are weak bleeding predictors, poorly reflecting coagulation in vivo. Thromboelastometry (ROTEM) provides early identification of coagulation disorders and can guide transfusion therapy by goals, reducing blood components transfusion.

Objective

The aim of this study is to describe coagulation profile of critically ill patients using ROTEM and evaluate the association between CCT and thromboelastometry.

Methods

This is a retrospective, observational study conducted in medical-surgical intensive care unit (ICU). Adult patients (≥18 years) admitted to ICU between November 2012 and December 2014, in whom ROTEM analyses were performed for bleeding management were included in this study. The first ROTEM and CCT after ICU admission were recorded simultaneously. Additionally, we collected data on blood components transfusion and hemostatic agents immediately after laboratory tests results.

Results

The study included 531 patients. Most ROTEM tests showed normal coagulation profile [INTEM (54.8%), EXTEM (54.1%) and FIBTEM (53.3%)] with divergent results in relation to CCT: low platelet count (51.8% in INTEM and 55.9% in EXTEM); prolonged aPTT (69.9% in INTEM and 63.7% in EXTEM) and higher INR (23.8% in INTEM and 27.4% in EXTEM). However 16,7% of patients with normocoagulability in ROTEM received platelet concentrates and 10% fresh frozen plasma.

Conclusion

The predominant ROTEM profile observed in this sample of critically ill patients was normal. In contrast, CCT suggested coagulopathy leading to a possibly unnecessary allogenic blood component transfusion. ROTEM test may avoid inappropriate allogeneic blood products transfusion in these patients.

Anticoagulant therapy in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) presents a complex pathophysiology characterized by pulmonary activated coagulation and reduced fibrinolysis. Despite advances in supportive care of this syndrome, morbidity and mortality remains high, leading to the need of novel therapies to combat this disease. Focus these therapies in the inhibition of ARDS development pathophysiology is essential. Beneficial effects of anticoagulants in ARDS have been proved in preclinical and clinical trials, thanks to its anticoagulant and anti-inflammatory properties. Moreover, local administration by nebulization in the alveolar compartment increases local efficacy and does not produce systemic bleeding. In this review the coagulation and fibrinolytic pathway and its pharmacological targets to treat ARDS are summarized.

A new era of thromboelastometry

Severe hemorrhage with necessity of allogeneic blood transfusion is common complication in intensive care unit and is associated with increased morbidity and mortality. Prompt recognition and treatment of bleeding causes becomes essential for the effective control of hemorrhage, rationalizing the use of allogeneic blood components, and in this way, preventing an occurrence of their potential adverse effects. Conventional coagulation tests such as prothrombin time and activated partial thromboplastin time present limitations in predicting bleeding and guiding transfusion therapy in critically ill patients. Viscoelastic tests such as thromboelastography and rotational thromboelastometry allow rapid detection of coagulopathy and goal-directed therapy with specific hemostatic drugs. The new era of thromboelastometry relies on its efficacy, practicality, reproducibility and cost-effectiveness to establish itself as the main diagnostic tool and transfusion guide in patients with severe active bleeding.

Hemostasis biomarkers and risk of sepsis: the REGARDS cohort

Essentials Few studies have investigated the risk of sepsis by baseline hemostasis biomarkers measures. Baseline hemostasis biomarkers and risk of sepsis was examined using case-control study design. Increased fibrinogen, factor IX, and factor XI levels may be associated with risk of sepsis. Hemostasis biomarkers may provide a target for sepsis mitigation or prevention.

SUMMARY

Background Sepsis is a major public health concern, responsible for more than 750 000 hospitalizations and 200 000 annual deaths in the USA. Few studies have investigated the association between baseline measurements of hemostasis biomarkers and the future risk of sepsis. Objective To determine whether hemostasis biomarkers levels measured at baseline in a cohort of community-dwelling participants are associated with the risk of future sepsis events. Methods We performed a nested case-control study within the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. We identified sepsis hospitalizations occurring over a 10-year period. There were 50 incident sepsis cases with baseline measurements of hemostasis (fibrinogen, factor VIII, FIX, FXI, protein C, and D-dimer). Using incidence density sampling, we matched the 50 sepsis cases with 200 controls by age, sex, and race. We used conditional logistic regression to evaluate the association between baseline hemostasis biomarkers and future sepsis events. Results Comparison of 50 sepsis cases with 200 non-sepsis controls showed that sepsis cases had lower education and income, were more likely to live in the stroke belt, had chronic lung disease, and had higher albumin level/creatinine level ratios (ACRs). Individuals with higher baseline fibrinogen levels (adjusted odds ratio [OR] per standard deviation: 1.40, 95% confidence interval [CI] 1.01-1.94), FIX levels ([OR] 1.46, 95% [CI] 1.03-2.07) and FXI levels ([OR]1.52, 95% [CI] 1.04-2.23) were more likely to experience a sepsis event. Conclusion Baseline fibrinogen, FIX and FXI levels are associated with future episodes of sepsis. Hemostasis biomarkers may provide targets for sepsis mitigation or prevention.

Platelet and endothelial cell P-selectin are required for host defense against Klebsiella pneumoniae-induced pneumosepsis

BACKGROUND

Sepsis is associated with activation of platelets and endothelial cells accompanied by enhanced P-selectin surface expression. Both platelet- and endothelial P-selectin have been associated with leukocyte recruitment and induction of inflammatory alterations. Klebsiella (K.) pneumoniae is a common human sepsis pathogen, particularly in the context of pneumonia.

METHODS

Wild-type (WT) and P-selectin-deficient (Selp(-/-) ) mice or bone marrow chimeric mice were infected with K. pneumoniae via the airways to induce pneumosepsis. Mice were sacrificed during early (12 h after infection) or late-stage (44 h) sepsis for analyses, or followed in a survival study.

RESULTS

Selp(-/-) mice displayed 10-1000-fold higher bacterial burdens in the lungs, blood and distant organs during late-stage sepsis. P-selectin deficiency did not influence leukocyte recruitment to the lungs, but was associated with decreased platelet-monocyte complexes and increased cytokine release. Bone marrow transfer studies revealed a role for both platelet and endothelial cell P-selectin as mice deficient in platelet or endothelial cell P-selectin displayed an intermediate phenotype in bacterial loads and survival compared with full wild-type or full knockout control mice.

CONCLUSION

Both platelet and endothelial cell P-selectin contribute to host defense during Klebsiella pneumosepsis.

Antiplatelet and antithrombotic activities of purpurogallin in vitro and in vivo

Enzymatic oxidation of pyrogallol was efficiently transformed to an oxidative product, purpurogallin (PPG). Here, the anticoagulant activities of PPG were examined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT), and the activities of thrombin and activated factor X (FXa). And, the effects of PPG on expression of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were evaluated in tumor necrosis factor (TNF)-α activated human umbilical vein endothelial cells (HUVECs). Treatment with PPG resulted in prolonged aPTT and PT and inhibition of the activities of thrombin and FXa, as well as inhibited production of thrombin and FXa in HUVECs. In addition, PPG inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. PPG also elicited anticoagulant effects in mice. In addition, treatment with PPG resulted in significant reduction of the PAI-1 to t-PA ratio. Collectively, PPG possesses antithrombotic activities and offers a basis for development of a novel anticoagulant. [BMB Reports 2014; 47(7): 376-381]

The efficacy and safety of plasma exchange in patients with sepsis and septic shock: a systematic review and meta-analysis

Introduction

Sepsis and septic shock are leading causes of intensive care unit (ICU) mortality. They are characterized by excessive inflammation, upregulation of procoagulant proteins and depletion of natural anticoagulants. Plasma exchange has the potential to improve survival in sepsis by removing inflammatory cytokines and restoring deficient plasma proteins. The objective of this study is to evaluate the efficacy and safety of plasma exchange in patients with sepsis.

Methods

We searched MEDLINE, EMBASE, CENTRAL, Scopus, reference lists of relevant articles, and grey literature for relevant citations. We included randomized controlled trials comparing plasma exchange or plasma filtration with usual care in critically ill patients with sepsis or septic shock. Two reviewers independently identified trials, extracted trial-level data and performed risk of bias assessments using the Cochrane Risk of Bias tool. The primary outcome was all-cause mortality reported at longest follow-up. Meta-analysis was performed using a random-effects model.

Results

Of 1,957 records identified, we included four unique trials enrolling a total of 194 patients (one enrolling adults only, two enrolling children only, one enrolling adults and children). The mean age of adult patients ranged from 38 to 53 years (n = 128) and the mean age of children ranged from 0.9 to 18 years (n = 66). All trials were at unclear to high risk of bias. The use of plasma exchange was not associated with a significant reduction in all-cause mortality (risk ratio (RR) 0.83, 95% confidence interval (CI) 0.45 to 1.52, I² 60%). In adults, plasma exchange was associated with reduced mortality (RR 0.63, 95% CI 0.42 to 0.96; I² 0%), but was not in children (RR 0.96, 95% CI 0.28 to 3.38; I² 60%). None of the trials reported ICU or hospital lengths of stay. Only one trial reported adverse events associated with plasma exchange including six episodes of hypotension and one allergic reaction to fresh frozen plasma.

Conclusions

Insufficient evidence exists to recommend plasma exchange as an adjunctive therapy for patients with sepsis or septic shock. Rigorous randomized controlled trials evaluating clinically relevant patient-centered outcomes are required to evaluate the impact of plasma exchange in this condition.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0699-2) contains supplementary material, which is available to authorized users.

Contribution of procoagulant phospholipids, thrombomodulin activity and thrombin generation assays as prognostic factors in intensive care patients with septic and non-septic organ failure

BACKGROUND

Multiple organ dysfunction syndrome (MODS) observed in patients with sepsis and in nonseptic patients organ failure (OF) is associated with a high mortality rate. We investigated whether new coagulation assays [quantification of procoagulant phospholipids (PPL) activity, functional assays measuring the activity of thrombomodulin (TMa) or tissue factor (TFa) and thrombin generation using calibrated automated thrombography (CAT)] could constitute new tools to better understand the physiopathology of MODS and have any prognostic value.

METHODS

We measured TMa, TFa, PPL and CAT in 32 healthy controls, 24 patients with sepsis and 26 patients with non-septic OF. We compared these parameters with usual coagulation assays [prothrombin time, activated partial thromboplastin time, protein C (PC), protein S, D-Dimers (D-Di), soluble thrombomodulin (sTM)] and markers of inflammation (IL-6, CRP). Samples were collected within 24 h of the diagnosis.

RESULTS

TMa, TFa, PPL, the lag time and time to thrombin peak levels were increased in both groups of patients. For both groups D-Di, IL-6, CRP and endogenous thrombin potential (ETP) were higher in non-survivors than in survivors, while PC and PPL were lower in non-survivors than in survivors. TMa increase was more marked in non-survivors patients with OF, while the ratio TMa/sTM was low in non-survivors with sepsis. Received operating characteristic (ROC) curve analysis indicated that thrombin peak and ETP were the more powerful discriminating factors in patients with sepsis or non-septic OF, respectively.

CONCLUSIONS

PPL, TMa and CAT assays could represent promising tools to identify patients with increased risk of mortality in MODS and could procure insights into pathogenesis of MODS.

Prognostic value of the International Society on Thrombosis and Haemostasis scoring system for overt disseminated intravascular coagulation in emergency department sepsis

PURPOSE

The International Society on Thrombosis and Haemostasis (ISTH) scoring system is a useful tool to diagnosis overt disseminated intravascular coagulation in clinical practice. The main purposes of this study were to investigate the prognostic value of the ISTH score in emergency department (ED) sepsis and compare the ISTH score with two established scoring systems, the Sequential Organ Failure Assessment (SOFA) score and Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and two biomarkers,procalcitonin (PCT) and C-reactive protein (CRP).

METHODS

Septic patients were consecutively enrolled from the ED of Beijing Chaoyang Hospital, China. The ISTH score, SOFA score and APACHE II score were calculated, and PCT and CRP levels were measured on enrollment. A 30-day follow-up was performed.

RESULTS

A total of 680 septic patients were enrolled in this study. The Cox regression analysis showed that the ISTH score had a greater effect on 30-day mortality prediction, and the receiver operating characteristic curve analysis showed that the accuracy of the ISTH score in prediction of 30-day mortality was better than the SOFA score, the APACHE II score, PCT and CRP. Combination of the ISTH score and CRP can enhance the predictive accuracy of 30-day mortality.

CONCLUSION

The ISTH score is a valuable scoring system in the prognosis evaluation in ED sepsis.

Antithrombotic activities of epi-sesamin in vitro and in vivo

Sesamin (SM) and epi-sesamin (ESM) were isolated from Asarum sieboldii and their anticoagulant activities were examined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT), and the activities of cell-based thrombin and activated factor X (FXa). In addition, the effects of SM and ESM on the expression of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were tested in tumor necrosis factor-α (TNF-α) activated human umbilical vein endothelial cells (HUVECs). Treatment with ESM, but not SM, resulted in significantly prolonged aPTT and PT and inhibition of the activities of thrombin and FXa, and ESM inhibited production of thrombin and FXa in HUVECs; and ESM inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. In accordance with these anticoagulant activities, ESM elicited anticoagulant effects in mice. In addition, treatment with ESM, but not SM, resulted in the inhibition of TNF-α-induced production of PAI-1, and treatment with ESM resulted in a significant reduction of the PAI-1 to t-PA ratio. Of particular interest, inhibition of the anticoagulant activity by ESM was more potent than that by SM, likely due to differences between their three-dimensional structures. Collectively, ESM possesses antithrombotic activities and offers a basis for the development of a novel anticoagulant.

Antithrombotic activities of pellitorine in vitro and in vivo

Pellitorine (PLT), an active amide compound, is well known to possess insecticidal, antibacterial and anticancer properties. However, the anti-coagulant functions of PLT are not studied yet. Here, the anticoagulant activities of PLT were examined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT), and the activities of cell-based thrombin and activated factor X (FXa). Furthermore, the effects of PLT on the expressions of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were tested in tumor necrosis factor (TNF)-α activated human umbilical vein endothelial cells (HUVECs). Treatment with PLT resulted in prolonged aPTT and PT and inhibition of the activities of thrombin and FXa, and PLT inhibited production of thrombin and FXa in HUVECs. And PLT inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. In accordance with these anticoagulant activities, PLT elicited anticoagulant effects in mouse. In addition, treatment with PLT resulted in the inhibition of TNF-α-induced production of PAI-1 and in the significant reduction of the PAI-1 to t-PA ratio. Collectively, PLT possesses antithrombotic activities and offers bases for development of a novel anticoagulant.

Novel biomarkers for early prediction of sepsis-induced disseminated intravascular coagulation in a mouse cecal ligation and puncture model

Introduction

The objective of this study was to identify biomarkers of sepsis-induced disseminated intravascular coagulation (DIC) among platelet-derived factors using biotin label-based custom protein microarray technology in a mouse cecal ligation and puncture (CLP) model.

Methods

KM mice were randomized into sham-operated and CLP groups. Blood samples were obtained immediately and at 1 h, 2 h, 6 h, 12 h, 24 h, 48 h and 72 h after establishment of the CLP for platelet count, coagulation assay and blood chemistry. Lung and mesentery tissues were examined histologically at all corresponding time points, looking for microthrombus formation. Serial protein microarray analysis was performed to detect platelet-derived factors.

Results

The survival rate 72 h post-CLP was 15%, but there was no mortality among the sham-operated mice. Compared with the sham group, the platelet count (n = 5, p < 0.05), fibrinogen concentration (n = 5, p < 0.05) and alanine aminotransferase level of the CLP group began to decrease significantly at 6 h post-CLP. Significant prolongation of prothrombin time (n = 5, p < 0.05) and activated partial thromboplastin time (n = 5, p < 0.05) and elevation of D-dimer (n = 5, p < 0.05) occurred after 6 h post-CLP. On histology, microthrombus formation in lung and mesentery tissue was observed in the CLP groups 6 h post-CLP and had become significant and extensive 12 h post-CLP (n = 5, p < 0.05). On protein microarray analysis and ELISA, thrombospondin (TSP), tissue inhibitor of metalloproteinase 1 (TIMP-1) and thymus chemokine-1 (TCK-1) all increased during the first 2 h post-CLP, then remained at a higher level than in the sham group for 72 h post-CLP (n = 5, p < 0.05).

Conclusions

TSP, TIMP-1 and TCK-1 are elevated in the early stage of sepsis-induced DIC in a mouse CLP model and may be considered early markers for sepsis-induced DIC.

Phospholipid scramblase expression in the pregnant mouse uterus in LPS-induced preterm delivery

Phospholipid scramblases (PLSCR), stimulated by proinflammatory cytokines, are thought to mediate the loss of lipid asymmetry in cell membranes, allowing for specific reactions in the coagulation cascade. The PLSCR may therefore provide a link between inflammation, coagulation, and, because thrombin is a uterotonic, preterm birth (PTB). To explore the relationship between PLSCR expression and inflammation-related PTB, we utilized reverse transcriptase-polymerase chain reaction and Western blot studies to quantify messenger RNA (mRNA) and protein expression for the 4 PLSCR homologues (PLSCR 1-4). Uteri from day 15 pregnant mice were harvested at several time points after intrauterine lipopolysaccharide (LPS) injection (or normal saline, for controls). Expression of mRNA in all 4 Plscr isoforms was demonstrated. Lipopolysaccharide treatment resulted in increased expression of PLSCR-1 and a decrease in Plscr4 mRNA, thereby demonstrating modulation of PLSCR-1 and PLSCR-4 in LPS-induced PTB. Additionally, protein expression was confirmed for all except PLSCR-4, with increased expression of PLSCR-1 after LPS treatment.

Systemic versus localized coagulation activation contributing to organ failure in critically ill patients

In the pathogenesis of sepsis, inflammation and coagulation play a pivotal role. Increasing evidence points to an extensive cross-talk between these two systems, whereby inflammation not only leads to activation of coagulation but coagulation also considerably affects inflammatory activity. The intricate relationship between inflammation and coagulation may not only be relevant for vascular atherothrombotic disease in general but has in certain clinical settings considerable consequences, for example in the pathogenesis of microvascular failure and subsequent multiple organ failure, as a result of severe infection and the associated systemic inflammatory response. Molecular pathways that contribute to inflammation-induced activation of coagulation have been precisely identified. Pro-inflammatory cytokines and other mediators are capable of activating the coagulation system and downregulating important physiological anticoagulant pathways. Activation of the coagulation system and ensuing thrombin generation is dependent on an interleukin-6-induced expression of tissue factor on activated mononuclear cells and endothelial cells and is insufficiently counteracted by physiological anticoagulant mechanisms and endogenous fibrinolysis. Interestingly, apart from the overall systemic responses, a differential local response in various vascular beds related to specific organs may occur.