Blood coagulation disorders in septic patients

Hemostatic Manifestations of Invasive Fungal Infections: A Comprehensive Review of Pathophysiological Mechanisms in Sepsis-Induced Hemostatic Disturbances, with a Focus on the Neonatal Population

Sepsis is a life-threatening condition that has challenged many clinicians over the years. The immune and hemostatic systems are the primary pillars of sepsis pathogenesis. Dysregulation of these intricate mechanisms significantly worsens the prognosis. Coagulopathy is a critical aspect of sepsis, with the degree of hemostatic impairment being a key determinant of poor outcomes. Although the concept of sepsis caused by bacteria has been well investigated, the fungal impact in the complexity of sepsis-related hemostatic derangement is not yet fully unraveled. In addition, sepsis occurs in patients across all age groups, with a particular concern for neonates, whose immature and vulnerable systems amplify the challenges. Notably, despite the high incidence of fungal septicemia in neonatal intensive care units (NICUs), along with its significant morbidity, mortality, and adverse neonatal outcomes, the impact of fungal sepsis on the neonatal hemostatic system-an essential determinant of prognosis-remains largely unexplored. The present review delves into the pathophysiologic mechanisms of sepsis-induced coagulopathy attributed to fungal infection, the mechanisms of fungal involvement in the hemostatic derangement, and attempts to contextualize this knowledge within the unique neonatal population. Finally, it aims to raise awareness of the critical need for a deep understanding of this hazardous condition to guide the development of optimal therapeutic strategies.

A Global Assessment of Coagulation Profile and a Novel Insight into Adamts-13 Implication in Neonatal Sepsis

Neonatal sepsis is a life-threatening condition associated with significant morbidity and mortality. Sepsis-induced coagulopathy is a well-recognized entity, signifying the strong cross-talk between inflammation and coagulation. The aim of the present study was to compare the coagulation profile between the acute phase of sepsis and recovery in term and preterm neonates. Additional comparisons to healthy neonates were undertaken. Levels of clotting, anti-clotting factors and ADAMTS-13 (A disintegrin and metalloprotease with thrombospondin type-1 motives), the cleaving protein of von Willebrand factor (VWF), were measured in 16 term and preterm neonates in the acute phase of infection and following recovery, as well as in 18 healthy neonates. Clotting times were prolonged, while levels of particular clotting factors were lower in the acute phase of infection compared to controls and recovery. On the other hand, levels of fibrinogen, factor VIII (FVIII) and VWF were significantly higher in the acute phase in comparison to controls and recovery, while they remained persistently higher in the infection group compared to controls. In regard to the anticlotting mechanism, a clear suppression was observed in septic neonates. ADAMTS-13 levels were significantly lower in the acute phase of infection in comparison to controls and recovery (p = 0.015 and 0.004, respectively), while a trend toward superimposed normalization was demonstrated post infection, as higher ADAMTS-13 levels were measured in recovered neonates compared to controls (p = 0.002). The coagulation profile is considerably deranged in neonatal sepsis. ADAMTS-13 deficiency in septic neonates is a novel finding with promising future implications, as ADAMTS-13 substitution may serve as a useful therapeutic option in neonatal sepsis, prompting further investigation in future studies.

TEG in the monitoring of coagulation changes in patients with sepsis and the clinical significance

Application values of thromboelastography (TEG) in dynamic monitoring of coagulation parameters of sepsis patients were investigated. Eighty-one patients with sepsis who were admitted to the ICU department of the General Hospital of Ningxia Medical University from April 1, 2015 to December 31, 2015 were collected. Clinical data of the patients were collected. Data were compared using 5 grouping methods: i) the 81 patients were divided into the sepsis group (n=45) and sepsis shock group (n=36); ii) patients were divided into two groups: group A (APACHE II score ≤13, n=51); group B (APACHE II score >13, n=30); iii) according to Disseminated Intravascular Coagulation Diagnosis Integral System (CDSS), patients were divided into non-disseminated intravascular coagulation (DIC) group (CDSS <7 points) and DIC group (CDSS ≥7 points); TEG indexes were compared between the two groups; iv) correlation between TEG indexes and Sequential Organ Failure Assessment (SOFA) scores was analyzed; v) patients were divided into survival group and non-survival group and correlations between TEG indicators and prognosis were analyzed. At 6 h after ICU entry, compared with sepsis group, R value and K time were significantly increased, LY30 was also increased, while MA value, coagulation index (CI), and α angle were significantly decreased in the septic shock group (P<0.05). At 6 h after ICU entry, compared with sepsis group, R value and K time were significantly increased, while MA value, CI, and α angle were significantly decreased in the septic shock group (P<0.05). Compared with the non-DIC group, the DIC group had prolonged K time, decreased α angle, increased R value, and decreased CI and MA value (P<0.05). With increase of SOFA scores, R value and K value increased significantly, and α angle, MA value, and CI decreased significantly (P<0.05). According to TEG, platelet function and fibrinogen function of DIC patients were significantly reduced, and the body showed hypocoagulability.

Characteristics of thrombin generation in a fulminant porcine sepsis model

INTRODUCTION

The activation of blood coagulation has been demonstrated in most cases of sepsis, however previous studies in humans could not detect hypercoagulability with global hemostasis assays. In a fulminant porcine sepsis model we analysed coagulation screening tests and thrombin generation to evaluate hemostatic alterations.

MATERIALS AND METHODS

Live Escherichia coli bacteria were inoculated to female pigs and prothrombin time, activated partial thromboplastin time, thrombin time and fibrinogen were measured by coagulometry. Platelet counts, platelet aggregates and platelet phosphatidyl serine (PS) expression were studied, furthermore in in vitro experiments the PS-inducing ability of septic and control plasmas was investigated by flow cytometry. Thrombin generation was carried out by the Ascent Fluoroscan reader and results were evaluated by the Thrombinoscope software.

RESULTS

Clotting assays showed a large variability, but no systematic changes during the 4-hour observation period. Platelet count significantly decreased and the number of platelet aggregates increased already by 2h compared to baseline values and to control animals. Although the increase in platelet PS expression was non-significant in the septic group, the septic plasma elicited PS expression on normal human red blood cells. Thrombin generation became significantly faster, but the quantity of formed thrombin demonstrated both hypo- and hypercoagulability depending on the setting of the assay.

CONCLUSIONS

Enhanced thrombin generation without activators and the PS-inducing capacity of septic plasma are signs of hemostatic activation during fulminant sepsis while the decreased amount of generated thrombin upon tissue factor and phospholipid induced activation demonstrates attenuated thrombin forming ability.

Efficacy and safety of low-molecular-weight heparin in patients with sepsis: a meta-analysis of randomized controlled trials

Low-molecular-weight heparin (LMWH) is part of standard supportive care. We conducted a meta-analysis to investigate the efficacy and safety of LMWH in septic patients. We searched Pubmed, Embase, CKNI and Wanfang database prior to July 2015 for randomized controlled trials investigating treatment with LMWH in septic patients. We identified 11 trials involving 594 septic patients. Meta-analysis showed that LMWH significantly reduced prothrombin time (mean differences [MD] −0.88; 95% CI −1.47 to −0.29), APACHE II score (MD −2.50; 95% CI −3.55 to −1.46), and 28-day mortality (risk ratio [RR] 0.72; 95% CI 0.57–0.91) as well as increased the platelet counts (MD 18.33; 95% CI 0.73–35.93) than the usual treatment. However, LMWH did not reduce D-dimer (MD −0.34; 95% CI −0.85 to 0.18). LMWH also significantly increased the bleeding events (RR 3.82; 95% CI 1.81–8.08). LMWH appears to reduce 28-day mortality and APACHE II score among septic patients. Bleeding complications should be monitored during the LMWH treatment. As for limited data about LMWH and sepsis in the English literature, only trials published in the Chinese were included in the meta-analysis.

Adjuvant treatment with crude rhubarb for patients with systemic inflammation reaction syndrome/sepsis: a meta-analysis of randomized controlled trials

OBJECTIVE

The objective of this study is to evaluate the benefits of adjuvant treatment with crude rhubarb in patients with systemic inflammation reaction syndrome/sepsis by conducting a meta-analysis.

METHODS

We conducted a systematic literature search of medical electronic databases (up to October 2013). Only randomized controlled trials (RCTs) assessing adjuvant treatment with crude rhubarb in septic patients were included.

RESULTS

A total of 15 RCTs with 869 patients were identified. Pooled analysis showed that interleukin 6 (standardized mean differences [SMDs], -1.30; 95% confidence intervals [CIs], -1.94 to -0.66), tumor necrosis factor α (SMD, -0.95; 95% CI, -1.55 to -0.36), procalcitonin (SMD, -1.50; 95% CI, -2.20 to -0.80), von Willebrand factor (mean differences [MDs], -144.11; 95% CI, -253.87 to -34.35), prothrombin time (MD, -2.38; 95% CI, -2.67 to -2.10), acute physiology and chronic health evaluation II scores (MD, -4.51; 95% CI, -5.30 to -3.73), and gastrointestinal dysfunction (risk ratio, 0.28; 95% CI, 0.16-0.49) were significantly reduced after treatment with crude rhubarb. Platelet number (MD, 58.16; 95% CI, 51.16-65.15) was significantly increased. However, crude rhubarb therapy did not significantly reduce 28-day mortality (risk ratio, 0.60; 95% CI, 0.36-1.00) compared with the usual treatment.

CONCLUSIONS

Adjuvant treatment with crude rhubarb appears to have additional benefits in septic patients. Antiinflammation and anticoagulant/antiaggregant properties may be its potential mechanism.

The 'procoagulopathy' of trauma: too much, too late?

PURPOSE OF REVIEW

Although early acute traumatic coagulopathy has received much recent attention, the procoagulopathy that often follows appears less appreciated. Thromboembolic disease following trauma is common and lethal, but very effective prophylactic strategies are available. These strategies are variably implemented because of the difficulty in quantifying the magnitude of procoagulopathy in individual patients.

RECENT FINDINGS

The principal mechanisms of the procoagulopathy of trauma include inflammation and disseminated intravascular coagulation, tissue factor and thrombin dysregulation, and circulating microparticles and phospholipids. Quantification of these factors may allow better risk assessment in individual patients, but as yet none of these tests is in routine practice. Viscoelastic measurement of developing clot strength identifies a procoagulant state in many trauma patients, and may be a guide to the best choice of the many options for thromboembolic prophylaxis.

SUMMARY

The logical next step following from the improved pathophysiological understanding of the procoagulopathy of trauma should be a simultaneous clinical trial of procoagulopathy diagnosis and thromboembolic prophylaxis.

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.

A Syrian golden hamster model recapitulating ebola hemorrhagic fever

Ebola hemorrhagic fever (EHF) is a severe viral infection for which no effective treatment or vaccine is currently available. While the nonhuman primate (NHP) model is used for final evaluation of experimental vaccines and therapeutic efficacy, rodent models have been widely used in ebolavirus research because of their convenience. However, the validity of rodent models has been questioned given their low predictive value for efficacy testing of vaccines and therapeutics, a result of the inconsistent manifestation of coagulopathy seen in EHF. Here, we describe a lethal Syrian hamster model of EHF using mouse-adapted Ebola virus. Infected hamsters displayed most clinical hallmarks of EHF, including severe coagulopathy and uncontrolled host immune responses. Thus, the hamster seems to be superior to the existing rodent models, offering a better tool for understanding the critical processes in pathogenesis and providing a new model for evaluating prophylactic and postexposure interventions prior to testing in NHPs.

Host response dynamics following lethal infection of rhesus macaques with Zaire ebolavirus

To gain further insight into the interdependent pathogenic processes in Ebola hemorrhagic fever (EHF), we have examined the dynamics of host responses in individual rhesus macaques infected with Zaire ebolavirus over the entire disease course. Examination of coagulation parameters revealed that decreased coagulation inhibitor activity triggered severe coagulopathy as indicated by prolonged coagulation times and decreased fibrinogen levels. This has been proposed as one of the significant mechanisms underlying disseminated intravascular coagulation in EHF patients. Furthermore, monitoring of expression levels for cytokines/chemokines suggested a mixed anti-inflammatory response syndrome (MARS), which indicates that a catastrophic uncontrolled immunological status contributes to the development of fatal hemorrhagic fever. These results highlight the pathological analogies between EHF and severe sepsis and not only contribute to our understanding of the pathogenic process, but will also help to establish novel postexposure treatment modalities.

Biomarkers of endothelial dysfunction: can they help us deciphering systemic inflammation and sepsis?

The endothelial integrity, as mechanical barrier against microorganisms and as natural "anticoagulant", is crucial for physiologic organ function. Systemic activation of the endothelium upon inflammation, sepsis, and septic shock is always ending in blood-tissue barrier disruption. With increasing dysfunction, uncontrolled clotting activation, capillary microthrombi formation, tissue edema, local hypoxia, and ischemia are initiated. This in turn enhances a vicious circle leading to multiple organ failure and death. Therefore, biomarkers reflecting this special compartment may help in the early detection of systemic inflammation and its complications. This review provides an overview of the most important endothelial biomarkers and their possible use in sepsis.

(+)-Nootkatone and (+)-valencene from rhizomes of Cyperus rotundus increase survival rates in septic mice due to heme oxygenase-1 induction

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizomes of Cyperus rotundus have been used as traditional folk medicine for the treatment of inflammatory diseases. However, the mechanism by which extract of rhizomes of Cyperus rotundus (ECR) elicits anti-inflammation has not been extensively investigated so far. The aim of the present study was to test whether heme oxygenase (HO)-1 induction is involved in the anti-inflammatory action of ECR.

MATERIALS AND METHODS

Induction of HO-1 and inhibition of inducible nitric oxide synthase (iNOS)/NO production by ECR and its 12 constituents (3 monoterpenes, 5 sesquiterpenes, and 4 aromatic compounds) were investigated using RAW264.7 cells in vitro. In addition, anti-inflammatory action of ECR and its two active ingredients (nookkatone, valencene) were confirmed in sepsis animal model in vivo.

RESULTS

ECR increased HO-1 expression in a concentration-dependent manner, which was correlated with significant inhibition of iNOS/NO production in LPS-activated RAW264.7 cells. Among 12 compounds isolated from ECR, mostly sesquiterpenes induced stronger HO-1 expression than monoterpenes in macrophage cells. Nootkatone and valencene (sesquiterpenes) significantly inhibited iNOS expression and NO production in LPS-simulated RAW264.7 cells. Inhibition of iNOS expression by nootkatone, valencene, and ECR were significantly reduced in siHO-1 RNA transfected cells. Furthermore, all three showed marked inhibition of high mobility group box-1 (HMGB1) in LPS-activated macrophages and increased survival rates in cecal ligation and puncture (CLP)-induced sepsis in mice.

CONCLUSIONS

Taken together, we concluded that possible anti-inflammatory mechanism of ECR is, at least, due to HO-1 induction, in which sesquiterpenes such as nootkatone and valencene play a crucial role.

Interactions between coagulation and complement--their role in inflammation

The parallel expression of activation products of the coagulation, fibrinolysis, and complement systems has long been observed in both clinical and experimental settings. Several interconnections between the individual components of these cascades have also been described, and the list of shared regulators is expanding. The co-existence and interplay of hemostatic and inflammatory mediators in the same microenvironment typically ensures a successful host immune defense in compromised barrier settings. However, dysregulation of the cascade activities or functions of inhibitors in one or both systems can result in clinical manifestations of disease, such as sepsis, systemic lupus erythematosus, or ischemia-reperfusion injury, with critical thrombotic and/or inflammatory complications. An appreciation of the precise relationship between complement activation and thrombosis may facilitate the development of novel therapeutics, as well as improve the clinical management of patients with thrombotic conditions that are characterized by complement-associated inflammatory responses.

Novel aspects of fibrin(ogen) fragments during inflammation

Coagulation is fundamental for the confinement of infection and/or the inflammatory response to a limited area. Under pathological inflammatory conditions such as arthritis, multiple sclerosis or sepsis, an uncontrolled activation of the coagulation system contributes to inflammation, microvascular failure and organ dysfunction. Coagulation is initiated by the activation of thrombin, which, in turn, triggers fibrin formation by the release of fibrinopeptides. Fibrin is cleaved by plasmin, resulting in clot lysis and an accompanied generation of fibrin fragments such as D and E fragments. Various coagulation factors, including fibrinogen and/or fibrin [fibrin(ogen)] and also fibrin degradation products, modulate the inflammatory response by affecting leukocyte migration and cytokine production. Fibrin fragments are mostly proinflammatory, however, Bβ15-42 in particular possesses potential antiinflammatory effects. Bβ15-42 inhibits Rho-kinase activation by dissociating Fyn from Rho and, hence prevents stress-induced loss of endothelial barrier function and also leukocyte migration. This article summarizes the state-of-the-art in inflammatory modulation by fibrin(ogen) and fibrin fragments. However, further research is required to gain better understanding of the entire role fibrin fragments play during inflammation and, possibly, disease development.