Disseminated Intravascular Coagulation: What's New?

[The Functional Roles and the Potential as Drug Targets of Glycoproteins Regulating Complement and Coagulation Pathways]

Complement (C) activation occurs via three pathways, namely the classical, lectin, and alternative pathways. Intercommunication occurs between the complement and coagulation systems, which can trigger tissue injury and inflammation. Disseminated intravascular coagulation (DIC) is a life-threatening disease characterized by disordered coagulation and systemic inflammation; here, the intercommunication between the complement and coagulation systems contributes to the development of DIC. Extracellular histones, which are contributors to the damage-associated molecular pattern, induce severe thrombosis. C5 is a key molecule in the intercommunication between the complement and coagulation systems and is associated with the development of lethal histone-induced thrombosis. Heparin and chondroitin sulfate (CS) are negatively charged, allowing them to bind to extracellular histones. As the coagulation system is less affected by CS than heparin, CS shows potential as an effective drug for the treatment of patients with DIC who have a high risk of bleeding. Complement receptor type-1-related gene Y (Crry) inhibits the complement pathway via binding to C3b and C4b. Hence, Crry is a potent inhibitor of the classical and alternative C pathways. The expression of Crry is decreased by the endothelial damage induced by extracellular histones. Crry dysfunction promotes the activation of C on the surface of endothelial cells. The prevention of C3 cleavage on endothelial cells might be a useful therapy targeting acute lung injury.

Recurrent Disseminated Intravascular Coagulation in Metastatic Castration-Resistant Prostate Cancer: A Case Report

Disseminated intravascular coagulation (DIC) is a systemic disease characterized by simultaneous thrombosis, bleeding, and partially excessive fibrinolysis. Systemic shock, trauma, bacterial toxins, and procoagulants-expressing solid and hematologic malignancies are common causes of this life-threatening hemorrhagic complication and often require treatment in intensive care units. We describe a case of an elderly man with recurrent severe bleeding events in the cause of DIC, including epistaxis, hemoptysis, hematuria, and gastrointestinal bleeding. Laboratory investigations revealed elevated prostate-specific antigen (PSA), suggesting an underlying prostate cancer. Despite intensified coagulatory therapy, the coagulation disorder could not be stabilized. A single injection of degarelix, a gonadotropin-releasing hormone (GnRH) receptor antagonist, led to rapid stabilization of the coagulation and decreased PSA within days. One year after initiating androgen-deprivation therapy, there were recurrent transfusion-requiring bleeding events, and a concomitant PSA increase occurred, suggesting metastatic castration-resistant disease associated with DIC. This case emphasizes DIC as a possible primary phenomenon and indicator for the progression of the underlying malignancy, as well as the importance of etiological therapies in the management of DIC.

Quantitative proteomics analysis of Angiostrongylus vasorum-induced alterations in dog serum sheds light on the pathogenesis of canine angiostrongylosis

Blood contains hundreds of proteins, reflecting ongoing cellular processes and immune reactions. Infections with the blood-dwelling cardiopulmonary nematode Angiostrongylus vasorum in dogs manifest with a broad spectrum of clinical signs including respiratory distress, bleeding diathesis and neurological signs, and are associated with a perturbed blood protein profile in dogs. However, current knowledge does not completely explain the observed pathologies induced by A. vasorum infections, including bleeding disorders. Using sera from experimentally infected dogs, dog serum proteome was analysed by quantitative mass spectrometry methods over several time points before and after inoculation. Following computational analysis, we identified 139 up- and downregulated proteins after infection (log2 ratio cut-off ≥ 1.0; q-value ≤ 0.05). Among upregulated proteins were chitinase 3-like 1 and pulmonary surfactant-associated protein B (log2 fold-changes ≥ 5). Pathway enrichment revealed the complement (especially the lectin pathway) and coagulation cascades as significantly affected upon analysis of downregulated proteins. Among them were mannan-binding lectin serine peptidases, ficolin, and coagulation factor XIII-B. These results bring new elements towards understanding the underlying pathomechanisms of bleeding diatheses observed in some A. vasorum-infected dogs.

Understanding and treating solid tumor-related disseminated intravascular coagulation in the "era" of targeted cancer therapies

A systemic activation of blood coagulation is usually present in many clinical conditions including the infectious or inflammatory ones and malignant disease as well. Depending upon circumstances, patients suffering from acute decompensated disseminated intravascular coagulation may be managed by a medical oncologist and either an internist or a physician working in an emergency and/or intensive care unit. In some cases, for example, the indolent ones, the activation of coagulation might not be easily detected by routine laboratory tests and not lead to clinical manifestations. Such a chronically activated intravascular coagulation can progress toward an overt decompensated disseminated intravascular coagulation. Traditional therapy of decompensated disseminated intravascular coagulation is based on reversing the underlying triggering disease and providing patients with adequate supportive treatment. The dilemma for the oncologist is whether or not the trigger cause can be treated and amended with a specific antineoplastic treatment, without worsening the consumption of platelets and the risk of bleeding. In light of the availability of new targeted therapies, the main criteria that should drive the strategy against solid cancer-related disseminated intravascular coagulation will be discussed.

Bone Marrow-Derived Mesenchymal Stem Cells-Mediated Protection Against Organ Dysfunction in Disseminated Intravascular Coagulation Is Associated With Peripheral Immune Responses

Disseminated intravascular coagulation (DIC) is a fatal thrombohemorrhagic disorder. Bone marrow-derived mesenchymal stem cells (BMSCs) are multipotent stem cells that have tremendous therapeutic effect. Our aim was to explore whether the immune mechanisms were associated with BMSCs-afforded protection against DIC. We generated a rat model of DIC by lipopolysaccharide (LPS, 3 mg/kg) injection via the tail vein. In the treatment group, rats were pre-treated with 1 × l0³ , 1 × l0⁴ , 1 × l0⁵ , and 1 × l0⁶ allogeneic BMSCs before LPS injection. Blood sample was withdrawn from the abdominal aorta at 0 (before), 4, and 8 h after LPS injection and used for biochemical analyses. After experiments, the mice were sacrificed and their organs were harvested and observed by H&E and PTAH staining. Continuous infusion of LPS into the rats gradually impaired the hemostatic parameters and damaged organ functions. However, pre-treatment with BMSCs dose-dependently improved the hemostatic parameters. Meanwhile, the treatment significantly suppressed the fibrin microthrombi formation and alleviated liver, heart, lung, and renal injuries. Flow cytometry analysis demonstrated that BMSCs pre-treatment inhibited LPS-induced upregulation of CD3⁺ CD8⁺ T cells and CD3⁺ /CD161a⁺ NKT cells in the peripheral blood. BMSCs pre-treatment reversed the upregualtion of the B-cell population and the percentage of CD43⁺ /CD172a⁺ monocytes in the DIC models. Finally, BMSCs pre-treatment decreased the levels of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1β (IL-1β), and interleukin-6 (IL-6) and increased the levels of interleukin-10 (IL-10) in LPS-induced DIC models. Pre-treatment with BMSCs can reduce coagulation and alleviate organ dysfunction via peripheral immune responses in LPS-induced DIC rat model. J. Cell. Biochem. 118: 3184-3192, 2017. © 2017 Wiley Periodicals, Inc.

Complement component 5 promotes lethal thrombosis

Extracellular histones promote platelet aggregation and thrombosis; this is followed by induction of coagulation disorder, which results in exhaustion of coagulation factors. Complement component 5 (C5) is known to be associated with platelet aggregation and coagulation system activation. To date, the pathological mechanism underlying liver injury has remained unclear. Here, we investigated whether C5 promotes liver injury associated with histone-induced lethal thrombosis. C5-sufficient and C5-deficient mice received single tail vein injections of purified, unfractionated histones obtained from calf thymus (45–75 μg/g). Subsequently, the mice were monitored for survival for up to 72 h. Based on the survival data, the 45 μg/g dose was used for analysis of blood cell count, liver function, blood coagulation ability, and promotion of platelet aggregation and platelet/leukocyte aggregate (PLA) production by extracellular histones. C5-deficient mice were protected from lethal thrombosis and had milder thrombocytopenia, consumptive coagulopathy, and liver injury with embolism and lower PLA production than C5-sufficient mice. These results indicate that C5 is associated with coagulation disorders, PLA production, and embolism-induced liver injury. In conclusion, C5 promotes liver injury associated with histone-induced lethal thrombosis.

The Neisseria meningitidis lpxL1 mutant induces less tissue factor expression and activity in primary human monocytes and monocyte-derived microvesicles than the wild type meningococcus

Neisseria meningitidis (N. meningitidis) may cause sepsis and meningitis. N. meningitidis with a mutated lpxL1 gene has five, instead of six, acyl chains in the lipid A moiety. Compared with patients infected with the wild type (wt) meningococcus, patients infected with the lpxL1 mutant have a mild meningococcal disease with less systemic inflammation and less coagulopathy. Circulating tissue factor (TF), the main initiator of coagulation, has a central role in the development of coagulation disturbances during sepsis. To study how TF was influenced by the lpxL1 mutant, human primary monocytes and whole blood were incubated with the lpxL1 mutant or the wt meningococcus (H44/76). Monocyte and microvesicle (MV)-associated TF expression and TF-dependent thrombin generation were measured. In both purified monocytes and whole blood, our data show that the lpxL1 mutant is a weaker inducer of monocyte and MV-associated TF compared with the wt. Our data indicate that low levels of circulating TF may contribute to the reduced coagulopathy reported in patients infected with lpxL1 mutants.

Disseminated intravascular coagulation following administration of sunitinib

Sunitinib is an increasingly used, orally administered targeted therapy, approved by the European Medicines Agency for the treatment of various types of cancer, including gastrointestinal stromal tumor unresectable or metastatic disease, following disease progression or intolerance to imatinib, and advanced or metastatic renal cell carcinoma, progressive well-differentiated pancreatic neuroendocrine tumors in patients with unresectable, locally advanced or metastatic disease. Sunitinib inhibits several tyrosine kinases, including the vascular endothelial growth factor receptor and the platelet-derived growth factor receptor. Tyrosine kinases inhibitor therapies are generally well-tolerated; nonetheless, they are not void of side effects. The majority of patients reported are grade 1 or 2, and include common and unspecific adverse events, including fatigue, gastrointestinal disorders, skin discoloration, altered taste, cough and dyspnea. Grade 3 or 4 adverse events, including bleeding and hemorrhage, are less frequent. The present study presented the first case of disseminated intravascular coagulation associated with the administration of sunitinib, shortly following the increase of sunitinib dosage.

Coagulopathy and its management in patients with severe burns

Severe burn injury is associated with systemic coagulopathy. The changes in coagulation described in patients with severe burns resemble those found patients with sepsis or major trauma. Coagulopathy in patients with severe burns is characterized by procoagulant changes, and impaired fibrinolytic and natural anticoagulation systems. Both the timing of onset and the severity of hemostatic derangements are related to the severity of the burn. The exact pathophysiology and time course of coagulopathy are uncertain, but, at least in part, result from hemodilution and hypothermia. As the occurrence of coagulopathy in patients with severe burns is associated with increased comorbidity and mortality, coagulopathy could be seen as a potential therapeutic target. Clear guidelines for the treatment of coagulopathy in patients with severe burns are lacking, but supportive measures and targeted treatments have been proposed. Supportive measures are aimed at avoiding preventable triggers such as tissue hypoperfusion caused by shock, or hemodilution and hypothermia following the usually aggressive fluid resuscitation in these patients. Suggested targeted treatments that could benefit patients with severe burns include systemic treatment with anticoagulants, but sufficient randomized controlled trial evidence is lacking.

Thromboelastography Parameter Predicts Outcome After Subarachnoid Hemorrhage: An Exploratory Analysis

OBJECTIVE

Hypercoagulability after subarachnoid hemorrhage (SAH) is well described and may be platelet mediated. Thromboelastography (TEG) provides a global assessment of coagulation. We sought to determine whether the maximum amplitude (MA) parameter of TEG, a measure of platelet strength and function, is associated with outcome after SAH.

METHODS

One hundred ten TEG analyses were performed for patients with moderate-to-severe SAH and compared with 6 healthy age- and sex-matched controls. TEG indices included MA, G value (G), alpha angle, and thrombus generation and were correlated to functional outcomes and laboratory tests including complete blood count, erythrocyte sedimentation rate, high sensitivity C-reactive protein, fibrinogen, and d-dimer, obtained on post-bleed days (PBDs) 1, 3, 5, 7, and 10.

RESULTS

MA was significantly elevated compared with controls on PBD 3 (70.0 mm ± 4.5 mm vs. 64.1 mm ± 6.5 mm; P = 0.02), PBD 5 (72.6 mm ± 5.3 mm vs. 64.1 mm ± 6.5 mm; P = 0.003), PBD 7 (73.0 mm ± 5.4 mm vs. 64.1 mm ± 6.5 mm; P = 0.003), and PBD 10 (73.4 mm ± 6.0 mm vs. 64.1 mm ± 6.5 mm; P = 0.005). G was significantly elevated compared with controls on PBD 3 (P = 0.03), PBD 5 (P = 0.01), PBD 7 (P = 0.01), and PBD 10 (P = 0.02). The only biomarker associated with poor outcome was CRP. Multivariate logistic regression demonstrated an association between elevated MA and outcome (odds ratio 39.1, P = 0.006) independent of CRP, age, Hunt Hess grade, and transfusion.

CONCLUSIONS

TEG indices are associated with poor outcome after SAH and may identify a platelet-mediated hypercoagulable state. The association between MA and outcome was stronger than that between traditional biomarkers and was independent of age and Hunt Hess grade.

Antithrombin: anti-inflammatory properties and clinical applications

Many humoral and cellular components participate in bidirectional communication between the coagulation and inflammation pathways. Natural anticoagulant proteins, including antithrombin (AT), tissue factor pathway inhibitor, and protein C, suppress proinflammatory mediators. Conversely, inflammation blunts anticoagulant activity and, when uncontrolled, promotes systemic inflammation-induced coagulation, such as those that occur in disseminated intravascular coagulation and severe sepsis. This review discusses the mechanisms of action and clinical use of AT concentrate in critically ill patients and in the settings of perioperative anticoagulation management for surgery and obstetrics. AT is a serine protease inhibitor with broad anticoagulant activity and potent anti-inflammatory properties. In clinical conditions associated with hereditary or acquired AT deficiency, administration of AT concentrate has been shown to restore proper haemostasis and attenuate inflammation. Of note, AT modulates inflammatory responses not only by inhibiting thrombin and other clotting factors that induce cytokine activity and leukocyte-endothelial cell interaction, but also by coagulation-independent effects, including direct interaction with cellular mediators of inflammation. An increasing body of evidence suggests that AT concentrate may be a potential therapeutic agent in certain clinical settings associated with inflammation. In addition to the well-known anticoagulation properties of AT for the treatment of hereditary AT deficiency, AT also possesses noteworthy anti-inflammatory properties that could be valuable in treating acquired AT deficiency, which often result in thrombotic states associated with an inflammatory component.

Peroxynitrite may affect fibrinolysis via the reduction of platelet-related fibrinolysis resistance and alteration of clot structure

We tested the hypothesis that in vitro peroxynitrite (ONOO(-), a product of activated inflammatory cells) may affect fibrinolysis in human blood through the reduction of platelet-related fibrinolysis resistance. It was found that ONOO(-) (25-300 µM) accelerated lysis of platelet-fibrin clots (in PRP) dose-dependently, whereas fibrinolysis of platelet-free clots was slightly inhibited by ≥ 1000 µM stressor. Concentrations of ONOO(-) affecting the lysis of platelet-rich clots, inhibited clot retraction (CR) in a dose-dependent manner. Thromboelastometry (ROTEM) measurements performed in PRP showed that treatment with ONOO(-) (threshold conc. 100 µM) prolongs clotting time, and reduces alpha angle, and clot formation velocity parameters indicating for reduced thrombin formation rate. In PRP, ONOO(-) (threshold conc. 100 µM) reduced the collagen-evoked exposure of phosphatidylserine (PS) on platelets' plasma membrane, the shedding of platelet-derived microparticles (PMP), and inhibited platelet-dependent thrombin generation (measured in artificial system), dose-dependently. As judged by confocal microscopy, similar ONOO(-) concentrations altered the architecture of clots formed in collagen-treated PRP. Clots formed in the presence of ONOO(-) were less dense and were composed of thicker fibers, which make them more susceptible to lysis. In platelet-depleted plasma, ONOO(-) (up to milimolar concentration) did not alter clot structure. Blockage of PS exposed on platelets resulted in an alteration of clot architecture toward more prone to lysis. ONOO(-), at lysis-affecting concentrations, inhibited the collagen-evoked secretion of fibrinolytic inhibitors from platelets. We conclude that physiologically relevant ONOO(-) concentrations may accelerate the lysis of platelet-fibrin clots predominantly via downregulation of platelet-related mechanisms including: platelet secretion, clot retraction, platelet procoagulant response, and the alteration in clot architecture associated with it.

Evaluation of obstetrical patients with disseminated intravascular coagulopathy - tertiary center experience

OBJECTIVE

The purpose of the present study is twofold: (a) to investigate the etiology of disseminated intravascular coagulopathy (DIC) caused by obstetrical conditions and (b) to present parameters that can be used in predicting DIC-related mortality in obstetrical patients.

MATERIAL AND METHOD

Obstetrical patients who had a delivery at or were referred (after delivery) to Obstetrics and Gynecology Clinic of Dicle University between July 2006 and December 2013 were retrospectively analyzed in this study. Those patients diagnosed with DIC were included in the study.

RESULTS

Fifty-six obstetrical patients carrying the diagnosis of DIC were included in this study. The overall mortality rate was 25% among these patients. More specifically, the mortality rate was 10.7% among patients with a DIC score ≤5 and 40.7% among those with a DIC score > 5. Multiple logistic regression analysis resulted in the finding that international normalized ratio (INR) and urea were among those factors affecting mortality in obstetrical DIC [OR: 8.44 (CI: 1.9-36.8), OR: 1.05 (CI: 1.0-1.1), respectively].

CONCLUSION

DIC is a syndrome that might be caused by obstetrical conditions. It is associated with high mortality and morbidity rates. In obstetrical DIC, urea is the most important factor affecting mortality. In addition, we are of the opinion that DIC score might guide mortality predictions as a determinant of prognosis.

An update for atypical haemolytic uraemic syndrome: diagnosis and treatment. A consensus document

Haemolytic uraemic syndrome (HUS) is a clinical entity defined as the triad of nonimmune haemolytic anaemia, thrombocytopenia, and acute renal failure, in which the underlying lesions are mediated by systemic thrombotic microangiopathy (TMA). Different causes can induce the TMA process that characterizes HUS. In this document we consider atypical HUS (aHUS) a sub-type of HUS in which the TMA phenomena are the consequence of the endotelial damage in the microvasculature of the kidneys and other organs due to a disregulation of the activity of the complement system. In recent years, a variety of aHUs-related mutations have been identified in genes of the the complement system, which can explain approximately 60% of the aHUS cases, and a number of mutations and polymorphisms have been functionally characterized. These findings have stablished that aHUS is a consequence of the insufficient regulation of the activiation of the complement on cell surfaces, leading to endotelial damage mediated by C5 and the complement terminal pathway. Eculizumab is a monoclonal antibody that inhibits the activation of C5 and blocks the generation of the pro-inflammatory molecule C5a and the formation of the cell membrane attack complex. In prospective studies in patients with aHUS, the use of Eculizumab has shown a fast and sustained interruption of the TMA process and it has been associated with significative long-term improvements in renal function, the interruption of plasma therapy and important reductions in the need of dialysis. According to the existing literature and the accumulated clinical experience, the Spanish aHUS Group published a consensus document with recommendations for the treatment of aHUs (Nefrologia 2013;33[1]:27-45). In the current online version of this document, we update the aetiological classification of TMAs, the pathophysiology of aHUS, its differential diagnosis and its therapeutic management.

Macrophage Activation Syndrome in Patients with Systemic Juvenile Idiopathic Arthritis under Treatment with Tocilizumab

OBJECTIVE

To identify macrophage activation syndrome (MAS) in patients with systemic juvenile idiopathic arthritis (sJIA) undergoing tocilizumab (TCZ) treatment, and to confirm laboratory marker changes and responses to treatment in patients with MAS receiving TCZ.

METHODS

In Japan, 394 patients with sJIA were registered in an all-patient registry surveillance of TCZ as of January 15, 2012. TCZ (8 mg/kg) was administered every 2 weeks to patients with sJIA. MAS, hemophagocytic lymphohistiocytosis, or Epstein-Barr virus-associated hemophagocytic syndrome (EB-VAHS) was reported in 23 of these patients (25 events). The Safety Evaluation Committee of Tocilizumab for JIA reviewed these cases and clinically evaluated the data and laboratory findings using their own therapeutic experience. Events were categorized into 4 groups: definitive MAS, probable MAS, EB-VAHS, and non-MAS.

RESULTS

The committee's review revealed 3 events of definitive MAS in 3 patients, 12 events of probable MAS in 11 patients, 2 events of EB-VAHS in 2 patients, and 8 events of non-MAS in 8 patients. There were 2 patients who developed 2 events: 2 events in 1 patient were classified into definitive MAS and probable MAS, and 2 events in another patient were classified into probable MAS. In patients with definitive or probable MAS, common clinical manifestations and laboratory findings of MAS were observed. Changes in laboratory data observed in patients with EB-VAHS were similar to those observed in patients with MAS.

CONCLUSION

These results suggest that the clinical/laboratory features in the course of MAS appear to be similar among patients regardless of whether TCZ is administered. Similarities in the pathophysiological background of MAS and EB-VAHS were also suggested.

Diagnosis of overt disseminated intravascular coagulation in critically Ill adults by Sonoclot coagulation analysis

Disseminated intravascular coagulation (DIC) diagnosis is hampered by the limited availability of reliable clinical or laboratory tests. Currently available tests are time consuming and expensive. We investigated whether coagulation and platelet function analyses using the Sonoclot system were suitable for overt DIC diagnosis in critically ill adults. This was an observational diagnostic study performed in 498 patients presenting with an underlying disorder associated with DIC. Overt DIC patients were identified according to an International Society on Thrombosis and Hemostasis (ISTH) score of >5. Coagulation and platelet parameters were analyzed using the Sonoclot system, and compared with ISTH as the gold standard. Receiver operating characteristic curves and area under the curves were used to evaluate the value of the Sonoclot parameters. There were no differences for age or gender between the groups. Significant correlations were observed between activated clotting time (ACT) and ISTH score (r = 0.7; P < 0.001), clot rate (CR) and ISTH score (r = 0.5; P < 0.001), platelet function (PF) and ISTH score (r = -0.6; P < 0.001), and PF and platelet count (r = 0.5; P < 0.001). An ACT cut-off value of 213.5 s alone or combined with CR presented good sensitivity (76.7 and 86.8 %, respectively) and specificity (96.2 and 93.3 %, respectively). Sonoclot analysis can be performed using a point-of-care device that effectively discriminates low and high ISTH scores, and that effectively predicts coagulation dysfunction in patients with overt DIC.

Importance of Kupffer cells in the development of acute liver injuries in mice

Kupffer cells reside within the liver sinusoid and serve as gatekeepers. They produce pro- and anti-inflammatory cytokines and other biologically important molecules upon the engagement of pattern recognition receptors such as Toll-like receptors. Kupffer cell-ablated mice established by in vivo treatment with clodronate liposomes have revealed many important features of Kupffer cells. In this paper, we review the importance of Kupffer cells in murine acute liver injuries and focus on the following two models: lipopolysaccharide (LPS)-induced liver injury, which is induced by priming with Propionibacterium acnes and subsequent challenge with LPS, and hypercoagulability-mediated acute liver failure such as that in concanavalin A (Con A)-induced hepatitis. Kupffer cells are required for LPS sensitization induced by P. acnes and are a major cellular source of interleukin-18, which induces acute liver injury following LPS challenge. Kupffer cells contribute to Con A-induced acute liver failure by initiating pathogenic, intrasinusoidal thrombosis in collaboration with sinusoidal endothelial cells. The mechanisms underlying these models may shed light on human liver injuries induced by various etiologies such as viral infection and/or abnormal metabolism.

Microparticle-associated tissue factor activity correlates with plasma levels of bacterial lipopolysaccharides in meningococcal septic shock

INTRODUCTION

The plasma level of bacterial lipopolysaccharides (LPS) is associated with activation of the coagulation system, inhibition of fibrinolysis and the nature of the clinical presentation and outcome in patients with meningococcal disease. Tissue factor (TF)-bearing microparticles (MPs) appear to contribute to the pathogenesis of disseminated intravascular coagulation (DIC). The aim of this study was to investigate the relationship between MP-associated TF activity and the level of bacterial LPS in plasma from patients with meningococcal septic shock and meningitis.

MATERIALS AND METHODS

MPs isolated from citrated plasmas were assessed for TF-dependent activity with both a plasma-based thrombin generation assay (CAT) and whole blood-based thromboelastometry (ROTEM). The LPS level was measured using a chromogenic Limulus amebocyte lysate assay.

RESULTS

MPs obtained from patients with meningococcal septic shock initiated significantly more efficient and TF-dependent thrombin generation in the CAT assay compared to MPs from patients with meningococcal meningitis. Differences in MP-associated TF activity between the septic shock patients and the meningitis patients were also evident when MPs were added to whole blood using ROTEM. The level of plasma LPS in patients with septic shock (range 2-2,100 EU/mL) was correlated with thrombogram parameters in the CAT assay; lagtime (r(s)=-0.84), time to peak (rs=-0.83), peak (r(s)=0.85) and ETP (r(s)=0.83).

CONCLUSIONS

MPs obtained from patients with meningococcal septic shock displayed more efficient TF-dependent thrombin generation and clot formation compared to MPs from meningitis patients. MP-associated TF activity was closely associated with plasma LPS levels in the septic shock group.

Kidney Transplantation from Donors with Severe Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC) is a syndrome characterized by massive formation of thrombin, which can lead to renal dysfunction or failure. Many transplant centers are reluctant to accept the kidneys from donors with DIC especially if renal dysfunction is present. We developed protocol of machine perfusion followed by tissue plasminogen activator (tPA) infusion in order to treat and evaluate DIC kidneys prior to transplantation. The kidneys were placed on machine preservation with tPA added to the perfusate prior to transplantation. Three kidneys were transplanted from two donors who sustained gunshot injuries to the brain. A biopsy at the time of organ recovery documented widespread fibrin thrombi in approximately 80% of the glomeruli. Serial biopsies showed interval improvement following machine perfusion and a normal appearing kidney three months after successful transplantation. The histological presence of DIC in a deceased organ donor, even if associated with renal dysfunction, is not a contraindication to renal transplantation. Machine perfusion and tPA infusions may contribute to the recovery and successful transplantation of such kidneys.

Tanshinone IIA protects rabbits against LPS-induced disseminated intravascular coagulation (DIC)

AIM

To evaluate the effects of tanshinone IIA (Tan IIA), a lipophilic diterpene from the Chinese herb Salvia miltiorrhiza, on lipopolysaccharide (LPS)-induced disseminated intravascular coagulation (DIC) in rabbits.

METHODS

LPS-induced DIC model was made in adult male New Zealand rabbits by continuous intravenous infusion of LPS (0.5 mg/kg) via marginal ear vein for 6 h. The animals were simultaneously administered with Tan IIA (1, 3 and 10 mg/kg) or heparin (500 000 IU/kg) through continuous infusion via the contralateral marginal ear vein for 6 h. Before and 2 and 6 h after the start of LPS infusion, blood samples were taken for biochemical analyses.

RESULTS

Continuous infusion of LPS into the rabbits gradually impaired the hemostatic parameters, damaged renal and liver functions, increased the plasma TNF-α level, and led to a high mortality rate (80%). Treatment of the rabbits with Tan IIA dose-dependently attenuated the increase in activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrin-fibrinogen degradation products (FDP); ameliorated the decrease in plasma levels of fibrinogen and platelets; and reversed the decline in activity of protein C and antithrombin III. Meanwhile, the treatment significantly suppressed the increase in the plasma levels of aminotransferase, creatinine and TNF-α, and led to much lower mortality (46.7% and 26.7% for the medium- and high-dose groups). Treatment of the rabbits with the high dose of heparin also effectively improved the hemostatic parameters, ameliorated liver and renal injuries, and reduced the plasma level of TNF-α, and significantly reduced the mortality (33.3%).

CONCLUSION

Tan IIA exerts a protective effect against DIC in rabbits.

Prospective comparison of new Japanese Association for Acute Medicine (JAAM) DIC and International Society of Thrombosis and Hemostasis (ISTH) DIC score in critically ill septic patients

INTRODUCTION

We prospectively compared the new Japanese Association for Acute Medicine (JAAM) score with the International Society of Thrombosis and Hemostasis (ISTH) score for diagnosis of disseminated intravascular coagulation (DIC) in septic patients admitted in a general critical care intensive care unit.

MATERIAL AND METHOD

Septic patients with platelet count of <150 × 10(9)/L were included. Both DIC scores were estimated from day 1 to day 4 along with APACHE II and SOFA scores.

RESULTS

Out of the 148 blood samples drawn from 42 patients (28 male & 14 female) the JAAM and ISTH DIC scores had an overall significant agreement (k=0.246, p<0.001) in 83 samples. JAAM score had higher diagnostic rates on all four days. Significant (p ≤ 0.001) day wise variation existed in JAAM and ISTH DIC scores. Correlation between JAAM DIC and ISTH DIC scores on day 1 (r=0.631) & day 4 (r=0.609) was significant (p<0.001). Pneumonia was the predominant cause of sepsis. Twenty seven (64.3%) patients died during their stay in ICU. Amongst DIC patients both severity scores (SOFA/APACHE II) and DIC scores (JAAM/ISTH) did not discriminate between survivors and non-survivors. Health care associated infection (p=0.040), high lactate levels (p=0.020) on day 1 and high procalcitonin levels (p=0.036) were found to have significant discriminating ability between survivors and non-survivors. Significantly shorter length of stay was observed amongst non-survivors (p=0.002).

CONCLUSIONS

In sepsis the JAAM DIC score identified most of the patients diagnosed by the overt ISTH criteria, but failed to discriminate between survivors and non-survivors amongst DIC patients.

The acute coagulopathy of trauma is due to impaired initial thrombin generation but not clot formation or clot strength

BACKGROUND

Acute coagulopathy of trauma (ACOT) has been described as a very early hypocoagulable state, but the mechanism remains controversial. One proposed mechanism is tissue hypoperfusion leading to protein C activation, with subsequent inhibition of Factors V and VIII. Variability in trauma has impeded the use of clinical data towards the elucidation of the mechanisms of ACOT, but thrombelastography (TEG) may provide insight by assessing hemostatic function from initial thrombin activation to fibrinolysis. We hypothesized that in a controlled animal model of trauma/hemorrhagic shock, clotting factor dysfunction is the predominant mechanism in early ACOT.

METHODS

Rats anesthetized by inhaled isoflurane (n = 6) underwent laparotomy, and hemorrhage was induced to maintain a MAP of 35 mm Hg for 30 min. Rats were then resuscitated with twice their shed blood volume in normal saline. TEG was performed at baseline, shock, and post-resuscitation periods. No heparin was given. Statistical analysis was performed by ANOVA with post-hoc Fisher's test.

RESULTS

Coagulation factor function was significantly impaired in the early stages of trauma/hemorrhagic shock. TEG R and SP-values were significantly increased from baseline to shock (P < 0.001) and from shock to post-resuscitation periods (P < 0.05). Delta (R-SP), a measure of thrombin generation, showed a significant increase (P < 0.05) from baseline to shock. No significant changes were found in K, Angle, MA, and LY30 values.

CONCLUSION

Clotting factor derangement leading to impaired thrombin generation is the principle etiology of ACOT in this model and not the dynamics of clot formation, fibrin cross-linking, clot strength/platelet function, or fibrinolysis.

Tissue factor and thrombosis: The clot starts here

Thrombosis, or complications from thrombosis, currently occupies the top three positions in the cardiovascular causes of morbidity and mortality in the developed world. There are a limited number of safe and effective drugs to prevent and treat thrombosis. Animal models of thrombosis are necessary to better understand the complex components and interactions involved in the formation of a clot. Tissue factor (TF) is required for the initiation of blood coagulation and likely plays a key role in both arterial and venous thrombosis. Understanding the role of TF in thrombosis may permit the development of new antithrombotic drugs. This review will focus on the role of TF in in vivo models of thrombosis.

[Septic vasculopathy]

Sepsis is one of the commonest causes of death around the world. The real frequency of cutaneous lesions in the setting of sepsis is unknown, but when they appear, they are usually one of the earliest signs of sepsis, thus allowing a rapid diagnosis of this potentially life-threatening condition. Four are the main physiopathologic mechanisms that can induce cutaneous lesions in sepsis: a) disseminated intravascular coagulation; b) direct vessel wall invasion by the microorganism; c) immune-mediated vasculitis, and d) septic embolism. We know that more than one of these mechanisms can appear in one single patient. In this review, we analyse these four mechanisms, their clinical presentation, and the histological findings that can be found in the cutaneous biopsy.

Hematopoietic and nonhematopoietic cell tissue factor activates the coagulation cascade in endotoxemic mice

Tissue factor (TF) is the primary activator of the coagulation cascade. During endotoxemia, TF expression leads to disseminated intravascular coagulation. However, the relative contribution of TF expression by different cell types to the activation of coagulation has not been defined. In this study, we investigated the effect of either a selective inhibition of TF expression or cell type-specific deletion of the TF gene (F3) on activation of coagulation in a mouse model of endotoxemia. We found that inhibition of TF on either hematopoietic or nonhematopoietic cells reduced plasma thrombin-antithrombin (TAT) levels 8 hours after administration of bacterial lipopolysaccharide (LPS). In addition, plasma TAT levels were significantly reduced in endotoxemic mice lacking the TF gene in either myeloid cells (TF(flox/flox),LysM(Cre) mice) or in both endothelial cells (ECs) and hematopoietic cells (TF(flox/flox),Tie-2(Cre) mice). However, deletion of the TF gene in ECs alone had no effect on LPS-induced plasma TAT levels. Similar results were observed in mice lacking TF in vascular smooth muscle cells. Finally, we found that mouse platelets do not express TF pre-mRNA or mRNA. Our data demonstrate that in a mouse model of endotoxemia activation of the coagulation cascade is initiated by TF expressed by myeloid cells and an unidentified nonhematopoietic cell type(s).

Cellular sources of tissue factor in endotoxemia and sepsis

Sepsis is a systemic host response to infection by pathogenic microorganisms. Activation of the coagulation cascade during endotoxemia and sepsis leads to disseminated intravascular coagulation. This review focuses on tissue factor expression by hematopoietic and non-hematopoietic cells and its contribution to the activation of coagulation during endotoxemia and sepsis.

Inflammatory stress and idiosyncratic hepatotoxicity: hints from animal models

Adverse drug reactions (ADRs) present a serious human health problem. They are major contributors to hospitalization and mortality throughout the world (Lazarou et al., 1998; Pirmohamed et al., 2004). A small fraction (less than 5%) of ADRs can be classified as "idiosyncratic." Idiosyncratic ADRs (IADRs) are caused by drugs with diverse pharmacological effects and occur at various times during drug therapy. Although IADRs affect a number of organs, liver toxicity occurs frequently and is the primary focus of this review. Because of the inconsistency of clinical data and the lack of experimental animal models, how IADRs arise is largely undefined. Generation of toxic drug metabolites and induction of specific immunity are frequently cited as causes of IADRs, but definitive evidence supporting either mechanism is lacking for most drugs. Among the more recent hypotheses for causation of IADRs is that inflammatory stress induced by exogenous or endogenous inflammagens is a susceptibility factor. In this review, we give a brief overview of idiosyncratic hepatotoxicity and the inflammatory response induced by bacterial lipopolysaccharide. We discuss the inflammatory stress hypothesis and use as examples two drugs that have caused IADRs in human patients: ranitidine and diclofenac. The review focuses on experimental animal models that support the inflammatory stress hypothesis and on the mechanisms of hepatotoxic response in these models. The need for design of epidemiological studies and the potential for implementation of inflammation interaction studies in preclinical toxicity screening are also discussed briefly.

Matrix metalloproteinase-10 is upregulated by thrombin in endothelial cells and increased in patients with enhanced thrombin generation

OBJECTIVE

Thrombin is a multifunctional serine protease that promotes vascular proinflammatory responses whose effect on endothelial MMP-10 expression has not previously been evaluated.

METHODS AND RESULTS

Thrombin induced endothelial MMP-10 mRNA and protein levels, through a protease-activated receptor-1 (PAR-1)-dependent mechanism, in a dose- and time-dependent manner. This effect was mimicked by a PAR-1 agonist peptide (TRAP-1) and antagonized by an anti-PAR-1 blocking antibody. MMP-10 induction was dependent on extracellular regulated kinase1/2 (ERK1/2) and c-jun N-terminal kinase (JNK) pathways. By serial deletion analysis, site-directed mutagenesis and electrophoretic mobility shift assay an AP-1 site in the proximal region of MMP-10 promoter was found to be critical for thrombin-induced MMP-10 transcriptional activity. Thrombin and TRAP-1 upregulated MMP-10 in murine endothelial cells in culture and in vivo in mouse aorta. This effect of thrombin was not observed in PAR-1-deficient mice. Interestingly, circulating MMP-10 levels (P<0.01) were augmented in patients with endothelial activation associated with high (disseminated intravascular coagulation) and moderate (previous acute myocardial infarction) systemic thrombin generation.

CONCLUSIONS

Thrombin induces MMP-10 through a PAR-1-dependent mechanism mediated by ERK1/2, JNK, and AP-1 activation. Endothelial MMP-10 upregulation could be regarded as a new proinflammatory effect of thrombin whose pathological consequences in thrombin-related disorders and plaque stability deserve further investigation.

Plasma tissue factor and tissue factor pathway inhibitor in patients with primary glomerulonephritis

OBJECTIVE

Nephrotic syndrome (NS) is associated with numerous blood coagulation abnormalities and a marked predisposition to thromboembolism. Fibrin formation within the glomeruli occurs in various forms of human and experimental glomerulonephritis and may play an important role in progressive glomerular injury. The aim of this study was to measure the plasma concentrations of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) and intravascular thrombin generation markers and to analyze their relationships in patients with primary glomerulonephritis.

MATERIAL AND METHODS

The study population comprised 57 patients (mean age 35.2 years; range 18-63 years) with primary glomerulonephritis: 36 with NS (NS group) and 21 without (non-NS group). The control group consisted of 24 sex- and age-matched healthy volunteers. TF and TFPI antigen, prothrombin fragment F 1+2 (PF 1+2) and thrombin-antithrombin III complex (TAT) concentrations in plasma were estimated using commercially available kits.

RESULTS

Serum TF and TFPI concentrations in both the NS and non-NS groups were higher than those observed in the control group. Moreover, there were significant differences in TF and TFPI concentrations between the NS and non-NS groups. TF:TFPI ratios in both the examined groups were constant and significantly higher than those in the control group. Positive correlations between TF and both PF 1+2 and TAT concentrations in the total cohort of patients were shown. Furthermore, a positive correlation between TF and TFPI concentrations was observed.

CONCLUSIONS

Our data support the hypothesis concerning activation of coagulation pathways in patients with primary glomerulonephritis. An inadequate TFPI concentration as a result of an elevated TF:TFPI ratio characterizes not only patients with clinical manifestations of NS but also patients with mild proteinuria.

MAP Kinase Phosphatase-1 and Septic Shock

Mitogen-activated protein (MAP)(§) kinase cascades are crucial signal transduction pathways in the biosynthesis of proinflammatory cytokines. MAP kinase phosphatase (MKP)-1, an archetypal member of the MKP family, plays a pivotal role in the feedback control of p38 and JNK. In vitro studies using cultured macrophages have provided strong evidence for a critical role of MKP-1 in the restraint of pro-inflammatory cytokine biosynthesis. Recently, a number of studies conducted using MKP-1 knockout mice have verified the importance of MKP-1 in the regulation of p38 and JNK and in the regulation of pro-inflammatory cytokine synthesis. Upon lipopolysaccharide challenge MKP-1 knockout mice produced dramatically greater amounts of inflammatory cytokines, developed severe hypotension, and multi-organ failure, and exhibited a remarkable increase in mortality. These studies demonstrate that MKP-1 is an essential feedback regulator of the innate immune response, and that it plays a critical role in preventing septic shock and multi-organ dysfunction during pathogenic infection.

Proteolytic inactivation of tissue factor pathway inhibitor by bacterial omptins

The immune response to infection includes activation of the blood clotting system, leading to extravascular fibrin deposition to limit the spread of invasive microorganisms. Some bacteria have evolved mechanisms to counteract this host response. Pla, a member of the omptin family of Gram-negative bacterial proteases, promotes the invasiveness of the plague bacterium, Yersinia pestis, by activating plasminogen to plasmin to digest fibrin. We now show that the endogenous anticoagulant tissue factor pathway inhibitor (TFPI) is also highly sensitive to proteolysis by Pla and its orthologs OmpT in Escherichia coli and PgtE in Salmonella enterica serovar Typhimurium. Using gene deletions, we demonstrate that bacterial inactivation of TFPI requires omptin expression. TFPI inactivation is mediated by proteolysis since Western blot analysis showed that TFPI cleavage correlated with loss of anticoagulant function in clotting assays. Rates of TFPI inactivation were much higher than rates of plasminogen activation, indicating that TFPI is a better substrate for omptins. We hypothesize that TFPI has evolved sensitivity to proteolytic inactivation by bacterial omptins to potentiate procoagulant responses to bacterial infection. This may contribute to the hemostatic imbalance in disseminated intravascular coagulation and other coagulopathies accompanying severe sepsis.

Coagulopathy in patients who experience snakebite

BACKGROUND/AIMS

Coagulopathy is a common complication of snakebite, but there is little information on the clinical importance of coagulopathy. We analyzed the characteristics of coagulopathy after envenomation.

METHODS

Ninety-eight patients who experienced snakebite were enrolled in this study. We divided all the patients into three groups by the ISTH DIC scoring system: the normal, simple coagulopathy and DIC groups. The coagulopathy group included both the simple coagulopathy and DIC groups. We then conducted a case-control study.

RESULTS

There was a significant decrease in the Hct, protein, albumin, ALP and cholesterol levels in the coagulopathy group, and only the cholesterol level was deceased in the DIC group (0<0.05). Leukocytosis and rhabdomyolysis were significantly associated with coagulopathy, and hemolysis and rhabdomyolysis were associated with DIC (p<0.05). The presence of rhabdomyolysis was considered a risk factor for coagulopathy (p<0.05). These conditions continued for up to six to seven days after the snakebite.

CONCLUSIONS

Evaluation of coagulopathy with using these characteristics is helpful to properly manage the patients who experience snakebite.

Coagulation disorders after traumatic brain injury

BACKGROUND

Over the past decade new insights in our understanding of coagulation have identified the prominent role of tissue factor. The brain is rich in tissue factor, and injury to the brain may initiate disturbances in local and systemic coagulation. We aimed to review the current knowledge on the pathophysiology, incidence, nature, prognosis and treatment of coagulation disorders following traumatic brain injury (TBI).

METHODS

We performed a MEDLINE search from 1966 to April 2007 with various MESH headings, focusing on head trauma and coagulopathy. We identified 441 eligible English language studies. These were reviewed for relevance by two independent investigators. A meta-analysis was performed to calculate the frequencies of coagulopathy after TBI and to determine the association of coagulopathy and outcome, expressed as odds ratios.

RESULTS

Eighty-two studies were relevant for the purpose of this review. Meta-analysis of 34 studies reporting the frequencies of coagulopathy after TBI, showed an overall prevalence of 32.7%. The presence of coagulopathy after TBI was related both to mortality (OR 9.0; 95%CI: 7.3-11.6) and unfavourable outcome (OR 36.3; 95%CI: 18.7-70.5).

CONCLUSIONS

We conclude that coagulopathy following traumatic brain injury is an important independent risk factor related to prognosis. Routine determination of the coagulation status should therefore be performed in all patients with traumatic brain injury. These data may have important implications in patient management. Well-performed prospective clinical trials should be undertaken as a priority to determine the beneficial effects of early treatment of coagulopathy.

SIRS-associated coagulopathy and organ dysfunction in critically ill patients with thrombocytopenia

BACKGROUND

Coagulopathy and thrombocytopenia often occur in critically ill patients, and disseminated intravascular coagulation (DIC) can lead to multiple organ dysfunction and a poor outcome. However, the relation between coagulopathy and systemic inflammatory response has not been thoroughly clarified. Thus, we evaluated coagulative activity, organ dysfunction, and systemic inflammatory response syndrome (SIRS) in critically ill patients with thrombocytopenia and examined the balance between coagulopathy and systemic inflammation.

PATIENTS AND METHODS

Two hundred seventy-three patients, who were admitted to 13 critical care centers in Japan and fulfilled the criteria of platelet count of less than 150*10(9)/L, were included. Coagulative variables (platelet count, fibrin/fibrinogen degradation products, and DIC scores), organ dysfunction index (Sequential Organ Failure Assessment [SOFA] score), and SIRS score in each patient were evaluated for 4 consecutive days after fulfilling the above entry criteria. The effect of SIRS on coagulopathy and organ dysfunction was evaluated in these patients.

RESULTS

Both the maximum SIRS score and entry SIRS score had significant relation to the maximum SOFA score during the observation period. Coagulation disorders indicated by the minimum platelet count, maximum DIC scores, and positivity for DIC worsened gradually with increases in SIRS scores. Both the minimum platelet count and maximum DIC scores were significantly correlated with the maximum SOFA score, indicating that a relation exists between coagulopathy and organ dysfunction.

CONCLUSIONS

In critically ill patients with thrombocytopenia, coagulopathy and organ dysfunction progress with significant mutual correlation, depending on the increase in SIRS scores. The SIRS-associated coagulopathy may play a critical role in inducing organ dysfunction after severe insult.