Recent advances in disseminated intravascular coagulation: endothelial cells and fibrinolysis in sepsis-induced DIC

The pathogenesis and management of heatstroke and heatstroke-induced lung injury

In the past two decades, record-breaking heat waves have caused an increasing number of heat-related deaths, including heatstroke, globally. Heatstroke is a life-threatening systemic condition characterized by a core body temperature >40°C and the subsequent development of multiple organ dysfunction syndrome. Lung injury is a well-documented complication of heatstroke and is usually the secondary cause of patient death. In recent years, extensive research has been conducted to investigate the underlying causes of heatstroke and heatstroke-induced lung injury. This review aims to consolidate and present the current understanding of the key pathogenic mechanisms involved in heatstroke and heatstroke-induced lung injury. In addition, systemic factors such as heat cytotoxicity, systemic inflammation, oxidative stress, endothelial cell dysfunction, and other factors are involved in the pathogenesis of lung injury in heatstroke. Furthermore, we also established current management strategies for heatstroke and heatstroke-induced lung injury. However, further investigation is required to fully understand the detailed pathogenesis of heatstroke so that potentially effective means of treating and preventing heatstroke and heatstroke-induced lung injury can be developed and studied.

Effect of hypofibrinolysis on clinical outcomes of patients with septic disseminated intravascular coagulation

BACKGROUND

This study investigated the utility of thromboelastometry (ROTEM) in assessing hypofibrinolysis among septic patients, specifically the association of hypofibrinolysis, as determined by ROTEM, with septic disseminated intravascular coagulation (DIC), organ dysfunction, and clinical outcomes.

METHODS

This single-center, retrospective analysis included adult septic patients admitted to Saga University Hospital from 2013 to 2017, with available ROTEM data. Hypofibrinolysis was assessed using the lysis index at 60 min (LI60) in extrinsic thromboelastometry (EXTEM). Based on their LI60 values, patients were classified into three groups: Hyper (LI60 ≤ 85), Normal (LI60 86-96), and Hypo (LI60 ≥ 97).

RESULTS

Among the 63 cases analyzed, the Hypo group showed significantly higher APACHEII and SOFA scores than the Normal group, indicating greater disease severity. Similarly, DIC and sepsis-induced coagulopathy (SIC) scores were notably higher in the Hypo group. The diagnostic performance of LI60 for ISTH-overt DIC showed an area under the curve (AUC) of 0.954, with an optimal cutoff value of 97 %, achieving 100 % sensitivity and 83.3 % specificity. The odds ratio for ISTH-overt DIC was 2.894, indicating a strong association between elevated LI60 and occurrence of DIC. Hypofibrinolysis predicted 28-day mortality and high SOFA scores (≥ 10) with high specificity and negative predictive value (NPV). A Kaplan-Meier curve revealed that the Hypo Group showed significantly worse clinical outcomes than the Normal and Hyper groups.

CONCLUSION

For septic patients, fibrinolysis suppression presenting as "hypofibrinolysis" (elevated LI60) is associated with poor prognosis and risk of higher organ dysfunction. Moreover, it is a significant predictor of adverse clinical outcomes in sepsis.

Non-invasive point-of-care optical technique for continuous in vivo assessment of microcirculatory function: Application to a preclinical model of early sepsis

Increased amplitude of peripheral vasomotion is a potential early marker of sepsis-related microcirculatory impairment; however, previous reports relied on clinically unsuitable invasive techniques. Hyperspectral near-infrared spectroscopy (hsNIRS) and diffuse correlation spectroscopy (DCS) are non-invasive, bedside techniques that can be paired to continuously monitor tissue hemoglobin content (HbT), oxygenation (StO2), and perfusion (rBF) to detect vasomotion as low-frequency microhemodynamic oscillations. While previous studies have primarily focused on the peripheral microcirculation, cerebral injury is also a common occurrence in sepsis and hsNIRS-DCS could be used to assess cerebral microcirculatory function. This work aimed to use a hybrid hsNIRS-DCS system to continuously monitor changes in the peripheral and cerebral microcirculation in a rat model of early sepsis. It was hypothesized that the skeletal muscle would be a more sensitive early indicator of sepsis-related changes in microhemodynamics than the brain. Control animals received saline while the experimental group received fecal slurry to induce sepsis. Subsequently, hsNIRS-DCS measurements were acquired from the skeletal muscle and brain for 6 h. Peripheral rBF rapidly decreased in septic animals, but there were no significant changes in peripheral HbT or StO2, nor cerebral HbT, rBF, or StO2. The power of low-frequency peripheral oscillations in all parameters (i.e., HbT, StO2, and rBF) as well as cerebral HbT oscillations were elevated in septic animals during the final 4 h. These findings suggest that in the early stages of sepsis, while vital organs like the brain are partly protected, changes in peripheral perfusion and vasomotor activity can be detected using hsNIRS-DCS. Future work will apply the technique to ICU patients.

Heparin-binding protein and sepsis-induced coagulopathy: Modulation of coagulation and fibrinolysis via the TGF-β signalling pathway

BACKGROUND

Heparin-binding protein (HBP) levels have been linked to organ failure and may represent an inflammatory biomarker of sepsis. We found disseminated intravascular coagulation (DIC) is associated with higher HBP levels in patients and in in vivo and in vitro models. This prospective, single-center observational study investigated the effects and underlying mechanisms of HBP on the coagulation cascade in sepsis.

METHODS

538 patients with sepsis from June 2016 to December 2019 were enrolled. Mechanisms underlying HBP and the coagulation system were investigated in human umbilical vein endothelial cells (HUVEC) and C57 mice.

RESULTS

Increased HBP was associated with sepsis-induced DIC. The optimal cutoff value was 37.5 ng/mL (sensitivity: 56 %, specificity: 65 %). Antithrombin-III (AT-III) activity, plasmin-a2 plasmin inhibitor complex (PIC), procalcitonin (PCT), hemoglobin, and HBP ≥37.5 ng/mL were associated with of DIC occurrence. In HUVECs &C57 mice models, Western blotting, qPCR, and immunohistochemistry analysis showed that the binding between HBP and TGF-β receptor 2 (TGFBR2) caused elevation of plasminogen activator inhibitor-1 (PAI-1) levels. Furthermore, we found that mice stimulated with HBP had higher levels of fibrinogen and D-dimer in the blood. HBP treatment caused the accumulation of fibrinogen in mice lung tissue. Treatment with TGFBR2-small interfering RNAs inhibited the effects.

CONCLUSION

Patients with sepsis having HBP ≥37.5 ng/mL at admission were more likely to develop DIC. HBP upregulates the expression of fibrinogen and PAI-1 via TGFBR2 and the TGF-β signalling pathway.

Prospective Application of Mesenchymal Stem Cell-Derived Exosomes in the Treatment of Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC) is an acquired disorder characterized by systemic activation of blood coagulation, which can arise from various causes. Owing to its abrupt onset, rapid progression, and high mortality rate, DIC presents a major clinical challenge. Anticoagulant drugs, such as heparin or low-molecular-weight heparin, are the current gold standard of treatment; however, these interventions pose considerable bleeding risks. Thus, safer and more effective therapeutic strategies are urgently required. Owing to their strong anti-inflammatory and tissue repair capabilities, mesenchymal stem cell-derived exosomes (MSC-Exos) have gained considerable attention as novel therapeutic options for numerous disorders, including DIC. Their stability in diverse pathological states highlights their potential as promising candidates for DIC therapy. This review presents the latest insights on the pathogenesis of DIC and anti-inflammatory and anticoagulant properties of MSC-Exos. We aimed to elucidate the potential mechanisms by which MSC-Exos influence DIC pathogenesis. We speculate that MSC-Exos offer a multifaceted approach to DIC treatment by attenuating neutrophil extracellular trap formation, modulating M1/M2 macrophage polarization, altering Nrf2/NF-κB signalling pathway to downregulate pro-inflammatory factors, and correcting imbalances in the coagulation-fibrinolysis system through anticoagulant routes. This suggests that MSC-Exos are a potential paradigm in DIC therapy, offering novel targets and treatment modalities for DIC management.

Coagulopathy and acute pancreatitis: pathophysiology and clinical treatment

Coagulopathy is a critical pathophysiological mechanism of acute pancreatitis (AP), arising from the complex interplay between innate immune, endothelial cells and platelets. Although initially beneficial for the host, uncontrolled and systemic activation of coagulation cascade in AP can lead to thrombotic and hemorrhagic complications, ranging from subclinical abnormalities in coagulation tests to severe clinical manifestations, such as disseminated intravascular coagulation. Initiation of coagulation activation and consequent thrombin generation is caused by expression of tissue factor on activated monocytes and is ineffectually offset by tissue factor pathway inhibitor. At the same time, endothelial-associated anticoagulant pathways, in particular the protein C system, is impaired by pro-inflammatory cytokines. Also, fibrin removal is severely obstructed by inactivation of the endogenous fibrinolytic system, mainly as a result of upregulation of its principal inhibitor, plasminogen activator inhibitor type 1. Finally, increased fibrin generation and impaired break down lead to deposition of (micro) vascular clots, which may contribute to tissue ischemia and ensuing organ dysfunction. Despite the high burden of coagulopathy that have a negative impact on AP patients' prognosis, there is no effective treatment yet. Although a variety of anticoagulants drugs have been evaluated in clinical trials, their beneficial effects are inconsistent, and they are also characterized by hemorrhagic complications. Future studies are called to unravel the pathophysiologic mechanisms involved in coagulopathy in AP, and to test novel therapeutics block coagulopathy in AP.

Synergy Between NK Cells and Monocytes in Potentiating Cardiovascular Disease Risk in Severe COVID-19

BACKGROUND

Evidence suggests that COVID-19 predisposes to cardiovascular diseases (CVDs). While monocytes/macrophages play a central role in the immunopathogenesis of atherosclerosis, less is known about their immunopathogenic mechanisms that lead to CVDs during COVID-19. Natural killer (NK) cells, which play an intermediary role during pathologies like atherosclerosis, are dysregulated during COVID-19. Here, we sought to investigate altered immune cells and their associations with CVD risk during severe COVID-19.

METHODS

We measured plasma biomarkers of CVDs and determined phenotypes of circulating immune subsets using spectral flow cytometry. We compared these between patients with severe COVID-19 (severe, n=31), those who recovered from severe COVID-19 (recovered, n=29), and SARS-CoV-2-uninfected controls (controls, n=17). In vivo observations were supported using in vitro assays to highlight possible mechanistic links between dysregulated immune subsets and biomarkers during and after COVID-19. We performed multidimensional analyses of published single-cell transcriptome data of monocytes and NK cells during severe COVID-19 to substantiate in vivo findings.

RESULTS

During severe COVID-19, we observed alterations in cardiometabolic biomarkers including oxidized-low-density lipoprotein, which showed decreased levels in severe and recovered groups. Severe patients exhibited dysregulated monocyte subsets, including increased frequencies of proinflammatory intermediate monocytes (also observed in the recovered) and decreased nonclassical monocytes. All identified NK-cell subsets in the severe COVID-19 group displayed increased expression of activation and tissue-resident markers, such as CD69 (cluster of differentiation 69). We observed significant correlations between altered immune subsets and plasma oxidized-low-density lipoprotein levels. In vitro assays revealed increased uptake of oxidized-low-density lipoprotein into monocyte-derived macrophages in the presence of NK cells activated by plasma of patients with severe COVID-19. Transcriptome analyses confirmed enriched proinflammatory responses and lipid dysregulation associated with epigenetic modifications in monocytes and NK cells during severe COVID-19.

CONCLUSIONS

Our study provides new insights into the involvement of monocytes and NK cells in the increased CVD risk observed during and after COVID-19.

Endothelial cell dynamics in sepsis-induced acute lung injury and acute respiratory distress syndrome: pathogenesis and therapeutic implications

Sepsis, a prevalent critical condition in clinics, continues to be the leading cause of death from infections and a global healthcare issue. Among the organs susceptible to the harmful effects of sepsis, the lungs are notably the most frequently affected. Consequently, patients with sepsis are predisposed to developing acute lung injury (ALI), and in severe cases, acute respiratory distress syndrome (ARDS). Nevertheless, the precise mechanisms associated with the onset of ALI/ARDS remain elusive. In recent years, there has been a growing emphasis on the role of endothelial cells (ECs), a cell type integral to lung barrier function, and their interactions with various stromal cells in sepsis-induced ALI/ARDS. In this comprehensive review, we summarize the involvement of endothelial cells and their intricate interplay with immune cells and stromal cells, including pulmonary epithelial cells and fibroblasts, in the pathogenesis of sepsis-induced ALI/ARDS, with particular emphasis placed on discussing the several pivotal pathways implicated in this process. Furthermore, we discuss the potential therapeutic interventions for modulating the functions of endothelial cells, their interactions with immune cells and stromal cells, and relevant pathways associated with ALI/ARDS to present a potential therapeutic strategy for managing sepsis and sepsis-induced ALI/ARDS.

Validation of the time to attain maximal clot amplitude after reaching maximal clot formation velocity parameter as a measure of fibrinolysis using rotational thromboelastometry and its application in the assessment of fibrinolytic resistance in septic patients: a prospective observational study: communication from the ISTH SSC Subcommittee on Fibrinolysis

BACKGROUND

In sepsis, fibrinolysis resistance correlates with worse outcomes. Practically, rotational thromboelastometry (ROTEM) is used to report residual clot amplitude relative to maximum amplitude at specified times after clot formation clot lysis indices (CLIs). However, healthy individuals can exhibit similar CLIs, thus making it challenging to solely diagnose the low fibrinolytic state. Furthermore, CLI does not include the kinetics of clot formation, which can affect overall fibrinolysis. Therefore, a more nuanced analysis, such as time to attain maximal clot amplitude after reaching maximal clot formation velocity (t-AUCi), is needed to better identify fibrinolysis resistance in sepsis.

OBJECTIVES

To evaluate the correlation between the degree of fibrinolytic activation and t-AUCi in healthy or septic individuals.

METHODS

Whole blood (n = 60) from septic or healthy donors was analyzed using tissue factor-activated (EXTEM) and nonactivated (NATEM) ROTEM assays. Lysis was initiated with tissue-type plasminogen activator, and CLI and t-AUCi were calculated. Standard coagulation tests and plasma fibrinolysis markers (D-dimer, plasmin-α2-antiplasmin complex, plasminogen activator inhibitor type 1, and plasminogen) were also measured.

RESULTS

t-AUCi values decreased with increasing fibrinolytic activity and correlated positively with CLI for different degrees of clot lysis both in EXTEM and NATEM. t-AUCi cutoff value of 1962.0 seconds in EXTEM predicted low fibrinolytic activity with 81.8% sensitivity and 83.7% specificity. In addition, t-AUCi is not influenced by clot retraction.

CONCLUSION

Whole-blood point-of-care ROTEM analyses with t-AUCi offers a more rapid and parametric evaluation of fibrinolytic potential compared with CLI, which can be used for a more rapid and accurate diagnosis of fibrinolysis resistance in sepsis.

Antarctic Krill Oil from Euphausia superba Ameliorates Carrageenan-Induced Thrombosis in a Mouse Model

FJH-KO obtained from Antarctic krill, especially Euphausia superba, has been reported to contain high amounts of omega-3 polyunsaturated fatty acids (n-3 PUFA) and to exhibit anticancer and anti-inflammatory properties. However, its antithrombotic effects have not yet been reported. This study aimed to investigate the antithrombotic effects of FJH-KO in carrageenan-induced thrombosis mouse models and human endothelial cells. Thrombosis was induced by carrageenan injection, whereas the mice received FJH-KO pretreatment. FJH-KO attenuated carrageenan-induced thrombus formation in mouse tissue vessels and prolonged tail bleeding. The inhibitory effect of FJH-KO was associated with decreased plasma levels of thromboxane B2, P-selectin, endothelin-1, β-thromboglobulin, platelet factor 4, serotonin, TNF-α, IL-1β, and IL-6. Meanwhile, FJH-KO induced plasma levels of prostacyclin I2 and plasminogen. In vitro, FJH-KO decreased the adhesion of THP-1 monocytes to human endothelial cells stimulated by TNF-α via eNOS activation and NO production. Furthermore, FJH-KO inhibited the expression of TNF-α-induced adhesion molecules such as ICAM-1 and VCAM-1 by suppressing the NF-κB signaling pathway. Taken together, our study demonstrates that FJH-KO protects against carrageenan-induced thrombosis by regulating endothelial cell activation and has potential as an antithrombotic agent.

Coagulofibrinolytic effects of recombinant soluble thrombomodulin in prolonged porcine cardiac arrest

Aim

To evaluate coagulofibrinolytic abnormalities and the effects of ART-123 (recombinant human thrombomodulin alpha) in a porcine model of cardiac arrest and prolonged cardiopulmonary resuscitation (CA/CPR).

Methods

Fifteen pigs (n = 5 per group) underwent 8 minutes of no-flow CA followed by 50 minutes of mechanical CPR, while 2 pigs underwent sham arrest. CA/CPR animals were randomized to receive saline or 1 mg/kg ART-123 pre-arrest (5 minutes prior to ventricular fibrillation) or post-arrest (2 minutes after initiation of CPR). Arterial and venous blood samples were drawn at multiple time points for blood gas analysis and measurement of plasma and whole blood markers of coagulation and fibrinolysis.

Results

In saline-treated CA/CPR, but not sham animals, robust and persistent activation of coagulation and fibrinolysis was observed throughout resuscitation. After 50 minutes of CPR, plasma tests and thromboelastography indicated a mix of hypercoagulability and consumptive coagulopathy. ART-123 had a robust anticoagulant effect, reducing both thrombin-antithrombin (TAT) complexes and d-dimer (p < 0.05 for each). The duration of anticoagulant effect varied depending on the timing of ART-123 administration. Similarly, ART-123 when given prior to cardiac arrest was found to have pro-fibrinolytic effects, increasing free tissue plasminogen activator (tPA, p = 0.02) and decreasing free plasminogen activator inhibitor-1 (PAI-1, p = 0.04).

Conclusion

A porcine model of prolonged CA/CPR reproduces many of the coagulofibrinolytic abnormalities observed in human cardiac arrest patients. ART-123 demonstrates a combination of anticoagulant and profibrinolytic effects, depending on the timing of its administration relative to cardiac arrest.

Synergistic Role of NK Cells and Monocytes in Promoting Atherogenesis in Severe COVID-19 Patients

Clinical data demonstrate an increased predisposition to cardiovascular disease (CVD) following severe COVID-19 infection. This may be driven by a dysregulated immune response associated with severe disease. Monocytes and vascular tissue resident macrophages play a critical role in atherosclerosis, the main pathology leading to ischemic CVD. Natural killer (NK) cells are a heterogenous group of cells that are critical during viral pathogenesis and are known to be dysregulated during severe COVID-19 infection. Their role in atherosclerotic cardiovascular disease has recently been described. However, the contribution of their altered phenotypes to atherogenesis following severe COVID-19 infection is unknown. We demonstrate for the first time that during and after severe COVID-19, circulating proinflammatory monocytes and activated NK cells act synergistically to increase uptake of oxidized low-density lipoprotein (Ox-LDL) into vascular tissue with subsequent foam cell generation leading to atherogenesis despite recovery from acute infection. Our data provide new insights, revealing the roles of monocytes/macrophages, and NK cells in COVID-19-related atherogenesis.

Value of the FDP/FIB ratio in predicting early severe bleeding events in patients with newly diagnosed acute promyelocytic leukemia

Severe bleeding is the leading cause of early death in patients with newly diagnosed acute promyelocytic leukemia (APL). However, there are no means for hemorrhagic risk stratification in APL. This study aimed to identify optimized predictors of severe bleeding events related to APL. A total of 109 consecutive patients with newly diagnosed APL from January 2015 to April 2022 were retrospectively investigated. A systematic review of computer-based patient medical records was conducted to obtain clinical date, including baseline characteristics, routine blood examination findings, coagulation and fibrinolysis indexes, and bleeding events. Among the 109 patients, 89 were classified into the no-severe bleeding group, while 20 had severe bleeding. Compared with the patients with no severe bleeding, the patients with severe bleeding had significantly higher circulating leukemic cell percentages, disseminated intravascular coagulation (DIC) scores, D-dimer (D-D) levels, and fibrin degradation product (FDP) levels. They also had lower fibrinogen (FIB) levels and a longer prothrombin time. Multivariate analysis revealed that the circulating leukemic cell percentage (OR = 1.040, CI = 1.008-1.072, P = 0.012), FIB level (OR = 0.101, CI = 0.011-0.896, P = 0.040), and FDP level (OR = 1.012, CI = 1.000-1.024, P = 0.047) were independent risk factors for severe bleeding. FDP/FIB, D-D/FIB, and seven meaningful indicators in the single-factor analysis were included in the receiver operating characteristic (ROC) curve analysis. The results showed that FDP/FIB was the best indicator for predicting severe bleeding related to newly diagnosed APL. The area under the ROC curve of FDP/FIB was 0.915, and the best cutoff value was 61.77, with 100% sensitivity and 74.2% specificity. Statistical analysis showed a higher incidence of severe bleeding and higher DIC scores when FDP/FIB was >61.77 in APL patients. FDP/FIB has obvious advantages in predicting the degree of bleeding associated with primary promyelocytic leukemia; the greater the FDP/FIB value, the more severe the bleeding. The risk of severe bleeding was the highest when FDP/FIB > 61.77.

Sepsis-Induced Coagulopathy Phenotype Induced by Oxidized High-Density Lipoprotein Associated with Increased Mortality in Septic-Shock Patients

Sepsis syndrome is a highly lethal uncontrolled response to an infection, which is characterized by sepsis-induced coagulopathy (SIC). High-density lipoprotein (HDL) exhibits antithrombotic activity, regulating coagulation in vascular endothelial cells. Sepsis induces the release of several proinflammatory molecules, including reactive oxygen species, which lead to an increase in oxidative stress in blood vessels. Thus, circulating lipoproteins, such as HDL, are oxidized to oxHDL, which promotes hemostatic dysfunction, acquiring prothrombotic properties linked to the severity of organ failure in septic-shock patients (SSP). However, a rigorous and comprehensive investigation demonstrating that oxHDL is associated with a coagulopathy-associated deleterious outcome of SSP, has not been reported. Thus, we investigated the participation of plasma oxHDL in coagulopathy-associated sepsis pathogenesis and elucidated the underlying molecular mechanism. A prospective study was conducted on 42 patients admitted to intensive care units, (26 SSP and 16 non-SSP) and 39 healthy volunteers. We found that an increased plasma oxHDL level in SSP was associated with a prothrombotic phenotype, increased mortality and elevated risk of death, which predicts mortality in SSP. The underlying mechanism indicates that oxHDL triggers an endothelial protein expression reprogramming of coagulation factors and procoagulant adhesion proteins, to produce a prothrombotic environment, mainly mediated by the endothelial LOX-1 receptor. Our study demonstrates that an increased plasma oxHDL level is associated with coagulopathy in SSP through a mechanism involving the endothelial LOX-1 receptor and endothelial protein expression regulation. Therefore, the plasma oxHDL level plays a role in the molecular mechanism associated with increased mortality in SSP.

Pathogenesis and Therapy of Coagulation Disorders in Severe Acute Pancreatitis

Ischemia superimposed upon pancreatic edema leads to acute necrotizing pancreatitis. One possible mechanism contributing to ischemia is intravascular thrombogenesis since fibrin deposits have been detected in pancreatic capillaries by electron microscope. Current experimental and clinical data provided compelling evidence that the disorders in the blood coagulation system play a critical role in the pathogenesis of severe acute pancreatitis (SAP). This leads to microcirculatory failure of intra- and extrapancreatic organs and multiple organ failure and increases the case fatality rate. However, the mechanism of coagulopathy underlying SAP is not yet clear, although some anticoagulant drugs have entered clinical practice showing improvement in prognosis. Thus, enhanced understanding of the process might improve the treatment strategies with safety and high efficacy. Herein, the pathogenesis of the coagulation system of SAP was reviewed with a focus on the coagulation pathway, intercellular interactions, and complement system, thereby illustrating some anticoagulant therapies and potential therapeutic targets.

Increased thrombin activatable fibrinolysis inhibitor activity is associated with hypofibrinolysis in dogs with sepsis

Introduction

Disorders of coagulation are well-recognized in dogs with sepsis, but data regarding fibrinolysis disorders are limited. We aimed to characterize fibrinolysis in dogs with sepsis compared to healthy controls. We hypothesized that dogs with sepsis would be hypofibrinolytic, and that hypofibrinolysis would be associated with non-survival.

Methods

This was a prospective observational cohort study. We enrolled 20 client-owned dogs with sepsis admitted to the Cornell University Hospital for Animals and 20 healthy pet dogs. Coagulation and fibrinolytic pathway proteins including antiplasmin activity (AP), antithrombin activity (AT), thrombin activatable fibrinolysis inhibitor activity (TAFI), D-dimer concentration, fibrinogen concentration, and plasminogen activity were measured and compared between groups. Overall coagulation potential, overall fibrinolysis potential, and overall hemostatic potential were calculated from the curve of fibrin clot formation and lysis over time.

Results

Compared to healthy controls, dogs with sepsis had lower AT (P = 0.009), higher AP (P = 0.002), higher TAFI (P = 0.0385), and higher concentrations of fibrinogen (P < 0.0001) and D-dimer (P = 0.0001). Dogs with sepsis also had greater overall coagulation potential (P = 0.003), overall hemostatic potential (P = 0.0015), and lower overall fibrinolysis potential (P = 0.0004). The extent of fibrinolysis was significantly negatively correlated with TAFI. No significant differences were observed between survivors and non-survivors.

Discussion

Dogs with sepsis were hypercoagulable and hypofibrinolytic compared to healthy dogs, suggesting potential utility of thromboprophylaxis in this patient population. The association between high TAFI and low overall fibrinolysis potential might provide a potential mechanism for this hypofibrinolysis.

Salvianolic acid A alleviates lipopolysaccharide-induced disseminated intravascular coagulation by inhibiting complement activation

Introduction

Disseminated intravascular coagulation (DIC) is a syndrome characterized by coagulopathy, microthrombus, and multiple organ failure. The complement system in DIC is overactivated, and the functions of complement and coagulation pathways are closely related. Our previous screening revealed that salvianolic acid A (SAA) has anti-complement activity. The hyper-activated complement system was involved in the lipopolysaccharide (LPS) induced DIC in rats. The effects of SAA anti-complement action on LPS-induced DIC in rats were investigated.

Methods

The complement activity of the classical pathway and alternative pathway was detected through an in vitro hemolysis assay. The binding sites of SAA and complement C3b were predicted by molecular docking. LPS-induced disseminated coagulation experiments were performed on male Wistar rats to assess coagulation function, complement activity, inflammation, biochemistry, blood routine, fibrinolysis, and survival.

Results

SAA had an anti-complement activity in vivo and in vitro and inhibited the complement activation in the classical and alternative pathway of complement. The infusion of LPS into the rats impaired the coagulation function, increased the plasma inflammatory cytokine level, complemented activation, reduced the clotting factor levels, fibrinogen, and platelets, damaged renal, liver, and lung functions, and led to a high mortality rate (85%). SAA treatment of rats inhibited complement activation and attenuated the significant increase in D-dimer, interleukin-6, alanine aminotransferase, and creatinine. It ameliorated the decrease in plasma levels of fibrinogen and platelets and reversed the decline in activity of protein C and antithrombin III. The treatment reduced kidney, liver, and lung damage, and significantly improved the survival rate of rats (46.2 and 78.6% for the low- and high-dose groups, respectively).

Conclusion

SAA reduced LPS-induced DIC by inhibiting complement activation. It has considerable potential in DIC treatment.

Empiric Anticoagulation Therapy in Hospitalized COVID-19 Patients: An Evaluation of Bleeding Risk Scores Performances in Predicting Bleeding Events

Currently, there is no standardized consensus on anticoagulation (AC) among patients with coronavirus disease (COVID-19), which has an overwhelming bleeding risk. We aimed to compare the patterns of AC in COVID-19 patients and compare two validated risk scores in predicting bleeding events. A retrospective review of medical records was conducted for COVID-19 patients who received empiric anticoagulation therapy. The primary outcomes included bleeding events, survival, and mechanical ventilation needs. We applied the HAS-BLED and ORBIT bleeding risk scores to assess the predictive accuracy, using c-statistics and the receiver operating curve (ROC) method. Of the included patients (n = 921), with a mean age of 58.1 ± 13.2, 51.6% received therapeutic AC and 48.4% received a prophylactic AC dose. Significantly higher values of d-dimer and C-reactive protein (CRP) among the therapeutic AC users (p < 0.001) were noted with a significantly prolonged duration of hospital stay and mechanical ventilation (p < 0.001 and p = 0.011, respectively). The mean value of the HAS-BLED and ORBIT scores were 2.53 ± 0.93 and 2.26 ± 1.29, respectively. The difference between the two tested scores for major bleeding and clinically relevant non-major bleeding was significant (p = 0.026 and 0.036, respectively) with modest bleeding predictive performances. The therapeutic AC was associated with an increased risk of bleeding. HAS-BLED showed greater accuracy than ORBIT in bleeding risk predictability.

Spectroscopy detects skeletal muscle microvascular dysfunction during onset of sepsis in a rat fecal peritonitis model

Sepsis is a dysregulated host inflammatory response to infection potentially leading to life-threatening organ dysfunction. The objectives of this study were to determine whether early microvascular dysfunction (MVD) in skeletal muscle can be detected as dynamic changes in microvascular hemoglobin (MVHb) levels using spectroscopy and whether MVD precedes organ histopathology in septic peritonitis. Skeletal muscle of male Sprague-Dawley rats was prepared for intravital microscopy. After intraperitoneal injection of fecal slurry or saline, microscopy and spectroscopy recordings were taken for 6 h. Capillary red blood cell (RBC) dynamics and SO₂ were quantified from digitized microscopy frames and MVHb levels were derived from spectroscopy data. Capillary RBC dynamics were significantly decreased by 4 h after peritoneal infection and preceded macrohemodynamic changes. At the same time, low-frequency oscillations in MVHb levels exhibited a significant increase in Power in parts of the muscle and resembled oscillations in RBC dynamics and SO₂. After completion of microscopy, tissues were collected. Histopathological alterations were not observed in livers, kidneys, brains, or muscles 6 h after induction of peritonitis. The findings of this study show that, in our rat model of sepsis, MVD occurs before detectable organ histopathology and includes ~ 30-s oscillations in MVHb. Our work highlights MVHb oscillations as one of the indicators of MVD onset and provides a foundation for the use of non-invasive spectroscopy to continuously monitor MVD in septic patients.

Utilising Network Pharmacology to Explore Underlying Mechanism of Astragalus membranaceus in Improving Sepsis-Induced Inflammatory Response by Regulating the Balance of IκBα and NF-κB in Rats

Objective

The purpose of the present study was to explore the mechanism of Astragalus membranaceus in the treatment of sepsis.

Methods

We searched the active components and targets of Astragalus membranaceus using the TCMSP and BATMAN databases. Then, the GeneCards, MalaCards, and OMIM databases were used to screen out relevant targets of sepsis. The common targets of the former two gene sets were uploaded to the STRING database to create an interaction network. DAVID was used to perform KEGG enrichment analysis of the core targets. Based on the results of KEGG and previous studies, key pathways for the development of sepsis were identified and experimentally validated.

Result

We obtained 3,370 sepsis-related targets in databases and 59 active components in Astragalus membranaceus through data mining, corresponding to 1,130 targets. The intersection of the two types of targets led to a total of 318 common targets and 84 core targets were obtained after screening again. The KEGG and previous studies showed that these 84 core targets were involved in sepsis by regulating TNF, MAPK, and PI3K pathways. TNF, MAPK8, NF-κB, and IκBα are crucial in sepsis. Experimental validation demonstrated that some markers in sepsis model rats were improved after the intervention with Astragalus granules and their chemical components. Among them, IL-1β, IL-6, and TNF-α in rat serum were reduced. The mRNA and protein expression of TNF-α, IL-6, MMP9, MAPK8, and NF-κB were reduced in rat blood. However, the mRNA and protein expression of IκBα and PI3K were increased in rat blood.

Conclusion

The AST could affect the TNF, PI3K, and MAPK pathway cascade responses centred on IκBα and NF-κB, attenuate the expression of IL-6 and MMP9, and interfere with the inflammatory response during sepsis.

Ferritin as prognostic marker in COVID-19: the FerVid study

BACKGROUND

In COVID-19 patients the progressive clinical deterioration seems secondary to the activation of a cytokine storm. Ferritin is considered a direct mediator of the immune system and some evidences suggested a shared physio-pathogenic basis between COVID-19 and 'Hyperferritinemic Syndromes.' The aim of our study was to evaluate the prognostic role of ferritin in COVID-19 patients.

METHODS

We retrospectively studied consecutive COVID-19 patients admitted to four Italian Internal Medicine Units. Role of potential prognostic markers was evaluated with binary logistic regression analysis and results were expressed as odds ratios (ORs) with the corresponding 95% confidence intervals (CIs). Poor outcome was defined as death or need to transfer in the intensive care unit.

RESULTS

Two hundred patients were included (mean age 68.75 ± 13.22 years). Ferritin value was highly elevated (>3000 ng/mL) in 8% of our population; 13% of patients were transferred to intensive care units and 12% of patients died. At multivariate analysis, highly elevated ferritin levels (OR 16.67 C.I. 4.89-57.57 p < 0.001) and hemoglobin < 10 g/dL (OR 8.88 C.I. 2.02-39.09 p = 0.004) were independently associated with a bad outcome.Patients with ferritin values > 3000 ng/ml appeared to have an inflammatory activation with elevated values of CRP and D-dimer and low values of lymphocyte count.

CONCLUSION

Our results confirm the prognostic role of ferritin in hospitalized COVID-19 patients. Patients with high ferritin levels should be considered critically ill and treated in an adequate setting. Furthermore, COVID-19 seems to share some characteristics with hyperferritinemic syndromes with potential therapeutic implications.

Endothelial METTL3 (Methyltransferase-Like 3) Inhibits Fibrinolysis by Promoting PAI-1 (Plasminogen Activator Inhibitor-1) Expression Through Enhancing Jun Proto-Oncogene N6-Methyladenosine Modification

OBJECTIVE

METTL3 (methyltransferase-like protein 3)-mediated N6-methyladenosine modification is the most abundant RNA modification on eukaryote mRNAs and plays a crucial role in diverse physiological and pathological processes. However, whether N6-methyladenosine modification has function in thrombosis is unknown. This study aims to determine the role of METTL3 in the endothelial cells-mediated thrombosis. Approach and Results: RNA-sequencing and real-time quantitative PCR revealed that the expression of PAI-1 (plasminogen activator inhibitor-1) was downregulated in METTL3 knockdown human umbilical vein endothelial cells. In vitro experiments showed that METTL3 suppressed fibrinolysis. Mechanically, RNA methylation sequencing and meRIP-quantitative real-time PCR showed that METTL3 catalyzed N6-methyladenosine modification on 3' UTR of JUN mRNA. Western blotting analysis showed that METTL3 promoted JUN protein expression. Chromatin immunoprecipitation analysis demonstrated that JUN bound to the PAI-1 promoter in human umbilical vein endothelial cells. Furthermore, mice challenged with lipopolysaccharide resulted in higher METTL3 expression in vessels. Endothelial-specific knockdown of Mettl3 decreased expression of active PAI-1 in plasma and attenuated fibrin deposition in livers and lungs during endotoxemia.

CONCLUSIONS

Our study reveals that METTL3-mediated N6-methyladenosine modification plays a crucial role in fibrinolysis and is an underlying target for the therapy of thrombotic disorders.

Fibrinolytic Impairment and Mortality in Pediatric Septic Shock: A Single-Center Prospective Observational Study

OBJECTIVES

Fibrinolytic shutdown is associated with poor prognosis in adult sepsis, but data in the pediatric population are sparse. This study aimed to identify the association between impaired fibrinolysis and mortality in pediatric septic shock.

DESIGN

A prospective, observational study conducted between August 2019 and August 2020.

SETTING

PICU at a pediatric tertiary hospital in Hanoi, Vietnam.

PATIENTS

Fifty-six pediatric patients who met septic shock criteria were enrolled.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Conventional coagulation tests and rotational thromboelastometry were performed at diagnosis. The fibrinolytic activity on extrinsic pathway thromboelastometry was negatively correlated with the Vasoactive-Inotropic Score at 24 hours post-PICU admission, peak lactate level during the first 24 hours, Pediatric Logistic Organ Dysfunction-2 score, and Pediatric Risk of Mortality-III score (all p < 0.05). Compared with patients with nonovert disseminated intravascular coagulation, dysfunction of less than two organs, and who survived, patients with overt disseminated intravascular coagulation, dysfunction of greater than two organs, and who died showed significantly lower fibrinolytic activity, represented by significantly higher lysis indexes (%) and lower maximum lysis (%) (all p < 0.05). The threshold values for prediction of mortality were lysis index 60 minutes greater than 97.5 (area under the curve = 0.86; sensitivity = 73%; specificity = 90%), maximum lysis less than 6.5 (area under the curve = 0.83; sensitivity = 73%; specificity = 87%), and lysis index 45 minutes greater than 99.5 (area under the curve = 0.83; sensitivity = 73%; specificity = 85%). Hypofibrinolysis was associated with prolonged PICU length of stay in survivors and with early mortality in nonsurvivors.

CONCLUSIONS

Fibrinolytic shutdown in pediatric septic shock is associated with an increase in disease severity and mortality. This highlights the need for further investigations regarding whether fibrinolytic therapy improved the outcome of pediatric septic shock.

An "occlusive thrombosis-on-a-chip" microfluidic device for investigating the effect of anti-thrombotic drugs

Cardiovascular disease remains one of the world's leading causes of death. Myocardial infarction (heart attack) is triggered by occlusion of coronary arteries by platelet-rich thrombi (clots). The development of new anti-platelet drugs to prevent myocardial infarction continues to be an active area of research and is dependent on accurately modelling the process of clot formation. Occlusive thrombi can be generated in vivo in a range of species, but these models are limited by variability and lack of relevance to human disease. Although in vitro models using human blood can overcome species-specific differences and improve translatability, many models do not generate occlusive thrombi. In those models that do achieve occlusion, time to occlusion is difficult to measure in an unbiased and objective manner. In this study we developed a simple and robust approach to determine occlusion time of a novel in vitro microfluidic assay. This highlighted the potential for occlusion to occur in thrombosis microfluidic devices through off-site coagulation, obscuring the effect of anti-platelet drugs. We therefore designed a novel occlusive thrombosis-on-a-chip microfluidic device that reliably generates occlusive thrombi at arterial shear rates by quenching downstream coagulation. We further validated our device and methods by using the approved anti-platelet drug, eptifibatide, recording a significant difference in the "time to occlude" in treated devices compared to control conditions. These results demonstrate that this device can be used to monitor the effect of antithrombotic drugs on time to occlude, and, for the first time, delivers this essential data in an unbiased and objective manner.

Disseminated intravascular coagulation associated organ failure in obstetric patients admitted to intensive care units: a multicenter study in China

We aimed to determine disseminated intravascular coagulation (DIC)-associated organ failure and underlying diseases based on data from three ICU wards in tertiary hospitals in China from 2008 to 2016. The diagnosis of DIC was confirmed by an International Society of Thrombosis and Hemostasis score greater than or equal to 5. The maternal outcomes included the changes in organ function 24 h after ICU admission. The durations of hospital stay and ICU stay were recorded as secondary outcomes. Among 297 ICU admissions (median Sequential Organ Failure Assessment score, 4) for obstetric diseases, there were 87 DIC cases, with an estimated DIC incidence of 87 per 87,580 deliveries. Postpartum hemorrhage was the leading disease associated with DIC (71, 81.6%), followed by hypertensive disorders (27, 31.0%), sepsis (15, 17.2%), acute fatty liver of pregnancy (11, 12.6%) and amniotic fluid embolism (10, 11.5%). Compared with patients without DIC, those with DIC had higher rates of multiple organ dysfunction syndrome/death (27.6% vs 4.8%, p = 0.000), organ failure (36.8% vs 24.3%, p = 0.029), among which organ failure included acute renal failure (32.2% vs 10.0%, p = 0.000), respiratory failure (16.1% vs 8.6%, p = 0.057), disturbance of consciousness (12.6% vs 2.4%, p = 0.000) and DIC group also had higher rates of massive transfusion (52.9% vs 21.9%, p = 0.000), hysterectomy (32.2% vs 15.7%, p = 0.001), longer ICU (4 days vs 2 days, p = 0.000) and hospital stays (14 days vs 11 days, p = 0.005). DIC and amniotic fluid embolism were independent risk factors for organ failure in patients admitted to the ICU. Postpartum hemorrhage was the leading cause of DIC associated organ failure in obstetrics admitted to the ICU. The control of obstetric bleeding in a timely manner may improve obstetric prognoses.

Obesity as a Risk Factor for Severe COVID-19 and Complications: A Review

Emerging data suggest that obesity is a major risk factor for the progression of major complications such as acute respiratory distress syndrome (ARDS), cytokine storm and coagulopathy in COVID-19. Understanding the mechanisms underlying the link between obesity and disease severity as a result of SARS-CoV-2 infection is crucial for the development of new therapeutic interventions and preventive measures in this high-risk group. We propose that multiple features of obesity contribute to the prevalence of severe COVID-19 and complications. First, viral entry can be facilitated by the upregulation of viral entry receptors, like angiotensin-converting enzyme 2 (ACE2), among others. Second, obesity-induced chronic inflammation and disruptions of insulin and leptin signaling can result in impaired viral clearance and a disproportionate or hyper-inflammatory response, which together with elevated ferritin levels can be a direct cause for ARDS and cytokine storm. Third, the negative consequences of obesity on blood coagulation can contribute to the progression of thrombus formation and hemorrhage. In this review we first summarize clinical findings on the relationship between obesity and COVID-19 disease severity and then further discuss potential mechanisms that could explain the risk for major complications in patients suffering from obesity.

Can disseminated intravascular coagulation scores predict mortality in COVID-19 patients?

Objectives

Complications related to coronavirus disease 2019 (COVID-19) may lead to disseminated intravascular coagulation (DIC), which has been reported to be among the known causes of mortality in such patients. This study aims to analyse the incidence of DIC in COVID-19 non-survivors and to assess the association between DIC and its comorbidities.

Methods

The medical records of 154 non-survivors of COVID-19, hospitalised between April 2020 and July 2020, were retrospectively analysed. The International Society on Thrombosis and Haemostasis (ISTH) criteria for DIC were applied to identify the occurrence of coagulopathy. The receiver-operating characteristic (ROC) analysis was used to assess the association between DIC and its comorbidities.

Results

Out of 154 non-survivors, non-overt DIC was observed in 94.8% of the patients, whereas only 5.2% fulfilled the overt criteria of DIC with a mean age 64.6 years. The mortality rate was 4.5 times higher among men than women. The D-dimer level was >250 ng/ml in 68.8% of the patients including 88.9% of the non-overt and 100% of the overt DIC patients. Prothrombin time (PT) in non-overt and overt DIC cases was 17.3 s and 24.4 s, respectively. Thrombotic event and chronic kidney disease were found to be the main predictors of DIC (p < 0.0001 and 0.03, respectively) followed by diabetes mellitus (DM) and hypertension (statistically insignificant).

Conclusions

Our study concludes that the ISTH DIC score cannot predict mortality as the COVID-19 related DIC differs from the sepsis-induced DIC. Among the seriously ill, older patients with comorbidities, increased levels of D-dimer and prolonged PT are more reliable parameters among COVID-19 non-survivors.

Endotheliopathy in septic conditions: mechanistic insight into intravascular coagulation

Endothelial cells play a key role in maintaining intravascular patency through their anticoagulant properties. They provide a favorable environment for plasma anticoagulant proteins, including antithrombin, tissue factor pathway inhibitor, and protein C. Under septic conditions, however, the anticoagulant properties of endothelial cells are compromised. Rather, activated/injured endothelial cells can provide a scaffold for intravascular coagulation. For example, the expression of tissue factor, an important initiator of the coagulation pathway, is induced on the surface of activated endothelial cells. Phosphatidylserine, a high-affinity scaffold for gamma-carboxyglutamate domain containing coagulation factors, including FII, FVII, FIX, and FX, is externalized to the outer leaflet of the plasma membrane of injured endothelial cells. Hemodilution decreases not only coagulation factors but also plasma anticoagulant proteins, resulting in unleashed activation of coagulation on the surface of activated/injured endothelial cells. The aberrant activation of coagulation can be suppressed in part by the supplementation of recombinant antithrombin and recombinant thrombomodulin. This review aims to overview the physiological and pathological functions of endothelial cells along with proof-of-concept in vitro studies. The pathophysiology of COVID-19-associated thrombosis is also discussed.

Recent advances in the research and management of sepsis-associated DIC

Disseminated intravascular coagulation (DIC) is a common and life-threatening complication in sepsis. Sepsis-associated DIC is recognized as the systemic activation in coagulation with suppressed fibrinolysis that leads to organ dysfunction in combination with systemic intravascular inflammation. In this process, thrombin contributes a key role in connecting both coagulation and inflammation. Endothelial injury, a result of sepsis, causes DIC due to the effect of multiple activated factors that include neutrophils, platelets, and damage-associated molecular patterns. Recent advances in the understanding of pathophysiology have made it possible to diagnose sepsis-associated DIC at earlier timing with better accuracy. However, progress in the treatment is still limited, and new therapeutics for sepsis-associated DIC are needed.

Anticoagulation and bleeding risk in patients with COVID-19

BACKGROUND

There is no current standardized approach to anticoagulation in patients with Coronavirus Disease 2019 (COVID-19) while potential bleeding risks remain. Our study characterizes the patterns of anticoagulation use in COVID-19 patients and the risk of related bleeding.

METHODS

This is a single center retrospective analysis of 355 adult patients with confirmed diagnosis of COVID-19 from March 1 to May 31, 2020. Chi-square was used to analyze the relationship between degree of anticoagulant dose and bleeding events by site. Multivariable logistic regression was used to look at factors associated with inpatient death.

RESULTS

61% of patients were being treated with prophylactic doses of anticoagulation, while 7% and 29% were being treated with sub-therapeutic and therapeutic anticoagulation (TA) doses respectively. In 44% of patients, we found that the decision to escalate the dose of anticoagulation was based on laboratory values characterizing the severity of COVID-19 such as rising D-dimer levels. There were significantly higher rates of bleeding from non-CNS/non-GI sites (p = 0.039) and from any bleeding site overall (p = 0.019) with TA. TA was associated with significantly higher rates of inpatient death (41.6% vs 15.3% p < 0.0001) compared to those without. All patients who developed CNS hemorrhage died p = 0.011. After multivariable logistic regression, only age OR 1.04 95% CI (1.01 to 1.07) p = 0.008 and therapeutic anticoagulation was associated with inpatient mortality OR 6.16 95% CI (2.96 to 12.83) p ≤ 0.0001.

CONCLUSION

The use of TA was significantly associated with increased risk of bleeding. Bleeding in turn exhibited trends towards higher inpatient death among patients with COVID-19. These findings should be interpreted with caution and larger more controlled studies are needed to verify the net effects of anticoagulation in patients with COVID-19.

Recognition of Plasminogen Activator Inhibitor Type 1 as the Primary Regulator of Fibrinolysis

The fibrinolytic system consists of a balance between rates of plasminogen activation and fibrin degradation, both of which are finely regulated by spatio-temporal mechanisms. Three distinct inhibitors of the fibrinolytic system that differently regulate these two steps are plasminogen activator inhibitor type-1 (PAI-1), α2-antiplasmin, and thrombin activatable fibrinolysis inhibitor (TAFI). In this review, we focus on the mechanisms by which PAI-1 governs total fibrinolytic activity to provide its essential role in many hemostatic disorders, including fibrinolytic shutdown after trauma. PAI-1 is a member of the serine protease inhibitor (SERPIN) superfamily and inhibits the protease activities of plasminogen activators (PAs) by forming complexes with PAs, thereby regulating fibrinolysis. The major PA in the vasculature is tissue-type PA (tPA) which is secreted from vascular endothelial cells (VECs) as an active enzyme and is retained on the surface of VECs. PAI-1, existing in molar excess to tPA in plasma, regulates the amount of free active tPA in plasma and on the surface of VECs by forming a tPA-PAI-1 complex. Thus, high plasma levels of PAI-1 are directly related to attenuated fibrinolysis and increased risk for thrombosis. Since plasma PAI-1 levels are highly elevated under a variety of pathological conditions, including infection and inflammation, the fibrinolytic potential in plasma and on VECs is readily suppressed to induce fibrinolytic shutdown. A congenital deficiency of PAI-1 in humans, in turn, leads to life-threatening bleeding. These considerations support the contention that PAI-1 is the primary regulator of the initial step of fibrinolysis and governs total fibrinolytic activity.

Multiple limb compartment syndrome as a manifestation of capillary leak syndrome secondary to metformin and dipeptidyl peptidase IV inhibitor overdose: A case report

RATIONALE

Capillary leak syndrome is a condition that increases systemic capillary permeability and causes characteristic manifestations such as recurrent hypovolemia, systemic edema, and hemoconcentration. Acute limb compartment syndrome is a possible complication of severe capillary leak syndrome. However, timely diagnosis and prompt treatment are challenging because of atypical presentation.

PATIENT CONCERNS

An 18-year-old woman with a history of clinical depression was admitted to our intensive care unit (ICU) because of metformin and vildagliptin overdose. She developed marked vasodilatory shock with recurrent severe hypovolemia and disseminated intravascular coagulation. After urgent hemodialysis and plasma exchange, she started to stabilize hemodynamically. However, her limbs became stone-hard with massive edema. Her serum creatinine kinase level increased to an extremely high level.

DIAGNOSIS

Extremities were distended, and her skin developed pallor with blistering. Intramuscular pressure in both forearms and lower legs was significantly elevated.

INTERVENTIONS

Decompressive fasciotomy was performed. Hemodialysis was continued because of rhabdomyolyses-induced acute kidney injury.

OUTCOMES

The patient was finally able to walk by herself at the time of hospital discharge on day 109.

LESSONS

The possibility of acute compartment syndrome should be considered in patients with marked capillary leakage, especially after aggressive fluid resuscitation. It is important to be aware of the compartment syndrome in an ICU setting because communication barriers often mask typical symptoms and make diagnosis difficult.

The unique characteristics of COVID-19 coagulopathy

Thrombotic complications and coagulopathy frequently occur in COVID-19. However, the characteristics of COVID-19-associated coagulopathy (CAC) are distinct from those seen with bacterial sepsis-induced coagulopathy (SIC) and disseminated intravascular coagulation (DIC), with CAC usually showing increased D-dimer and fibrinogen levels but initially minimal abnormalities in prothrombin time and platelet count. Venous thromboembolism and arterial thrombosis are more frequent in CAC compared to SIC/DIC. Clinical and laboratory features of CAC overlap somewhat with a hemophagocytic syndrome, antiphospholipid syndrome, and thrombotic microangiopathy. We summarize the key characteristics of representative coagulopathies, discussing similarities and differences so as to define the unique character of CAC.

Clinical investigation of the utility of a pair of coagulation-fibrinolysis markers for definite diagnosis of sepsis-induced disseminated intravascular coagulation: A single-center, diagnostic, prospective, observational study

BACKGROUND

Disseminated intravascular coagulation (DIC) often occurs with sepsis. A scoring system has been used for the diagnosis of DIC, but the system included at least 4 parameters. The purpose of this study was to propose a simple set of DIC criteria with coagulation-fibrinolysis markers (CFMs).

METHODS

Patients with ≥2 signs of systemic inflammatory response syndrome and a quick Sequential Organ Failure Assessment score ≥ 2 points were investigated. All blood samples were collected on Days 0, 1, 3, and 7. Cutoff values of CFMs were calculated by receiver operating curve analysis. Positive predictive values (PPVs) and negative predictive values (NPVs) for the Japanese Association for Acute Medicine (JAAM) DIC criteria were evaluated by pairing the markers. Differences were analyzed by the Mann-Whitney U test, Kruskal-Wallis test, and the log-rank test.

RESULTS

A total of 107 patients were enrolled. The cutoff values of soluble fibrin (SF), protein C (PC), and plasminogen activator inhibitor (PAI)-1 were 48 μg/mL, 42%, and 71 ng/mL according to the International Society of Thrombosis and Hemostasis DIC criteria. The PPV of the severe SFxPC group was 100% for the JAAM DIC criteria, excluding Day 0.

CONCLUSION

Cutoff values of SF over 48 μg/mL and PC <42% could almost definitely identify JAAM DIC.

Tetrahydropalmatine has a therapeutic effect in a lipopolysaccharide-induced disseminated intravascular coagulation model

Objectives

The aim of this study was to determine the therapeutic effects of tetrahydropalmatine (Tet) on disseminated intravascular coagulation (DIC) by exploring the role of Tet using a lipopolysaccharide (LPS)-induced DIC model.

Methods/Materials: We established a mouse DIC model by injecting LPS. Hematoxylin-eosin (HE) staining was performed to detect liver and kidney damage. Blood samples were obtained to determine liver and kidney injury indexes, coagulation indexes, and inflammatory cytokines. An in vitro cell inflammation model was also established. Tumor necrosis factor-α (TNF-α) levels and nuclear factor kappa B (NF-κB) signaling pathway activation were determined by western blot.

Result

Tet ameliorated the damage to organ tissues, improved coagulation indexes, and reduced the inflammatory cytokine production in LPS-induced mouse DIC. Tet also inhibited TNF-α expression by suppressing NF-κB signaling pathway activation in an in vitro LPS model using RAW 264.7 macrophages.

Conclusions

Tet has a mitigating and therapeutic effect on the LPS-induced DIC model via anticoagulant and anti-inflammatory effects, showing its potential as an adjunct to DIC treatment.

Advance in the Management of Sepsis-Induced Coagulopathy and Disseminated Intravascular Coagulation

Coagulopathy commonly occurs in sepsis as a critical host response to infection that can progress to disseminated intravascular coagulation (DIC) with an increased mortality. Recent studies have further defined factors responsible for the thromboinflammatory response and intravascular thrombosis, including neutrophil extracellular traps, extracellular vesicles, damage-associated molecular patterns, and endothelial glycocalyx shedding. Diagnosing DIC facilitates sepsis management, and is associated with improved outcomes. Although the International Society on Thrombosis and Haemostasis (ISTH) has proposed criteria for diagnosing overt DIC, these criteria are not suitable for early detection. Accordingly, the ISTH DIC Scientific Standardization Committee has proposed a new category termed "sepsis-induced coagulopathy (SIC)" to facilitate earlier diagnosis of DIC and potentially more rapid interventions in these critically ill patients. Therapy of SIC includes both treatment of the underlying infection and correcting the coagulopathy, with most therapeutic approaches focusing on anticoagulant therapy. Recently, a phase III trial of recombinant thrombomodulin was performed in coagulopathic patients. Although the 28-day mortality was improved by 2.6% (absolute difference), it did not reach statistical significance. However, in patients who met entry criteria for SIC at baseline, the mortality difference was approximately 5% without increased risk of bleeding. In this review, we discuss current advances in managing SIC and DIC.

Exchange protein directly activated by cAMP plays a critical role in regulation of vascular fibrinolysis

Plasmin-mediated fibrinolysis at the surface of vascular endothelial cells (SVEC) plays a key role in maintaining vascular hemostasis, in which the cAMP pathway participates. After externalization to the SVEC, annexin A2 (ANXA2) serves as a platform for conversion of plasminogen to plasmin. Here we describe a regulatory role of the exchange protein directly activated by cAMP (EPAC) in ANXA2 externalization and vascular fibrinolysis. Knockout of EPAC1 in mice results in a decreased ANXA2 expression on the SVEC associated with increased fibrin deposition and fibrinolytic dysfunction. Reduced levels of EPAC1 are also found in endocardial tissues beneath atrial mural thrombi in patients. Notably, administration of recombinant ANXA2 ameliorates fibrinolytic dysfunction in the EPAC1-null mice. Mechanistically, EPAC1 regulates the SVEC plasminogen conversion depended on ANXA2. EPAC1 promotes tyrosine-23 phosphorylation of ANXA2, a prerequisite for its recruitment to the SVEC. Our data thus reveal a novel regulatory role for EPAC1 in vascular fibrinolysis.

Comparison of Antithrombin III and Pentoxifylline Treatments in Gram Negative Sepsis Patients Developing Disseminated Intravascular Coagulation

Objective:

The aim of this study was to evaluate the effects of antithrombin III (AT III) and pentoxifylline treatments on the gram negative septic patients with disseminated intravascular coagulation (DIC).

Method:

For six days after plasma AT III activity dropped lower than 80% in Gram-patients who developed DIC were treated with AT III (90-120 IU/kg/day in 6 hours) or pentoxifylline (1.5 mg/kg/h in 6 hours) Fibrinogen, FDP, D-dimer, complete blood count, AT III activity, and DIC scores were calculated and recorded.

Results:

The coagulation tests, AT III activity and FDP started to improve from the second day of treatment with both treatments (p<0.05). D-Dimer started to decrease on the second day of treatment with pentoxifylline (p<0.001) and fourth day of AT III treatment (p<0.05). Fibrinogen levels decreased on the second day of pentoxifylline treatment (p<0.05) and on the last day of AT III treatment (p<0.001). DIC scores started to decrease on the last day of treatment with AT III treatment (p<0.001) and on the third day of treatment with pentoxifylline (p<0.05).

Conclusion:

Both ATIII and pentoxifylline treatments had positive effects on fibrinogen, FDP, D-Dimer, AT III activity and DIC scores in patients with Gram-negative sepsis who developed DIC.

Comparison of a new criteria for sepsis-induced coagulopathy and International Society on Thrombosis and Haemostasis disseminated intravascular coagulation score in critically ill patients with sepsis 3.0: a retrospective study

Recently, new criteria for sepsis-induced coagulopathy (SIC) were developed, including the sequential organ failure assessment (SOFA) criteria. The objective of this study was to evaluate the new SIC criteria in patients diagnosed with sepsis 3.0. Data from patients diagnosed with sepsis 3.0 after ICU admission were retrospectively obtained from July 2013 to June 2014. Relevant demographic, clinical, and laboratory parameters were noted. This study included 252 patients. The International Society on Thrombosis and Haemostasis (ISTH) disseminated intravascular coagulation (DIC), modified ISTH-DIC, and SIC scores were higher among nonsurvivors (P < 0.0001). The Acute Physiology and Chronic Health Evaluation II (P < 0.001), ISTH (P = 0.001), modified ISTH (P = 0.001), and SIC scores (P = 0.007) were independent predictors of ICU mortality. Using the receiver operating characteristic curve, SOFA had the greatest power for predicting ICU mortality; ISTH or modified ISTH score had greater predictive power than the SIC score. There were strong correlations between SIC score and ISTH (P < 0.0001), modified ISTH (P < 0.0001), the Acute Physiology and Chronic Health Evaluation II (P = 0.012), and SOFA (P < 0.0001) scores. More nonsurvivors were diagnosed with DIC using the ISTH and modified ISTH criteria (P < 0.001). In contrast, there was no significant difference in the proportion of patients with SIC between both groups (P = 0.055). ISTH score, modified ISTH score, and SIC score were independent risk factors for ICU mortality. Compared with the ISTH and modified ISTH scores, SIC score showed no advantage in diagnosing sepsis-associated coagulopathy or DIC. The application of these three criteria in patients with sepsis 3.0 needs further evaluation.

Clinical Investigation of Coagulation Markers for Early Detection of Sepsis-Induced Disseminated Intravascular Coagulation: A Single-Center, Prospective Observational Study

Disseminated intravascular coagulation (DIC) often complicates sepsis, and its early treatment is crucial for improving patient outcomes. Coagulation markers may enable earlier diagnosis of DIC. The purpose of this study was to evaluate whether the risk of DIC onset can be predicted using coagulation markers. Patients who showed symptoms of systemic inflammatory response syndrome ≥2 and the quick Sequential Organ Failure Assessment score ≥2 points were investigated. All blood samples collected from the time of hospital admission to 7 days postadmission were investigated. Patients were classified according to time of DIC onset (1) no DIC group (not DIC developed), (2) pre-DIC group (DIC onset >24 hours after admission), (3) DIC group (DIC onset at time of the admission) and according to cutoff values of coagulation markers, High group and Low group. Statistical differences were analyzed by log-rank test, Kruskal-Wallis rank test, and Friedman test. A total of 107 patients were enrolled in the study. Soluble fibrin (SF), plasminogen activator inhibitor (PAI)-1, and d-dimer levels were significantly increased even under pre-DIC conditions. Japanese Association for Acute Medicine (JAAM) DIC scores increased significantly over time in the High SF group (≥31.0 µg/mL) and High PAI-1 group (≥49.0 ng/mL), while JAAM DIC scores in the Low SF group remained ≤3 until day 7. We proposed the cutoff values of SF as 31 µg/mL to detect early phase of DIC. Soluble fibrin might be useful not only to predict DIC but also to exclude a diagnosis of DIC.

Biomarkers of disseminated intravascular coagulation in pediatric intensive care unit in Thailand

INTRODUCTION

Disseminated intravascular coagulation (DIC) is a systemic activation of hemostatic system caused by several causes. Biomarkers including antithrombin (AT), protein C (PC), and thrombomodulin (TM) were reported as the additional markers for DIC in adults. This study aimed to determine the association between biomarkers among patients with overt DIC (ODIC) and nonovert DIC (NDIC) in children in PICU.

METHODS

We enrolled 103 subjects, aged 1 month-18 years, who were admitted to PICU at Chiang Mai University (CMU) Hospital >24 hours with underlying conditions predisposing to DIC were enrolled. Biomarkers were tested after 24 hours of admission. Subject who had NDIC on the 1^st investigations would have other tests on days 3-5 of admission.

RESULTS

The incidence of ODIC by the International Society on Thrombosis and Hemostasis (ISTH) DIC score was found 24%. The bleeding, thrombosis, and death were significantly higher in ODIC group (P < 0.05). Mean levels of AT and PC in ODIC group were significantly different from NDIC one (66.9% vs 79.9%, P < 0.001 and 46.1% vs 59.2%, P = 0.004, respectively) while mean level of TM was not different between two groups. Adding AT to DIC score was better than the original score for predict mortality [area under curve (AUC) = 0.662 vs AUC = 0.65] and bleeding (AUC = 0.751 vs AUC = 0.732).

CONCLUSIONS

ODIC is prevalent among critically ill children. Adverse outcomes were more commonly found in children with ODIC. AT and PC levels after 24 hours of PICU admission seem to be the useful biomarkers for ODIC in PICU.

Direct factor Xa inhibition attenuates acute lung injury progression via modulation of the PAR-2/NF-κB signaling pathway

The role of coagulation in acute lung injury (ALI) remains unclear. As factor Xa-dependent protease-activated receptor 2 (PAR-2) is reported to be an important target in blood coagulation and other processes, an inhibitor of factor Xa, rivaroxaban, was tested in vivo in C57BL/6 mice with ALI induced by intratracheal injections of lipopolysaccharide (LPS) and in vitro in LPS-stimulated human umbilical vein endothelial cells. Plasma concentrations and coagulation indices were measured in mice fed normal chow or chow containing rivaroxaban (0.2 or 0.4 mg/g) for 10 days. The rivaroxaban-treated mice had significantly reduced neutrophil sequestration with preservation of the lung tissue architecture compared with that in the untreated controls. The levels of tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6, as well as total protein and Evans blue concentrations, were all significantly reduced in bronchoalveolar lavage fluid from mice treated with rivaroxaban. Rivaroxaban treatment also ameliorated the LPS-induced PAR-2 increase and nuclear factor kappa B (NF-κB) activation. In vitro, cells treated with rivaroxaban had higher cell viability with an attenuation of LPS-induced increases in membrane permeability and proinflammatory cytokine levels, as well as reduced apoptosis. Furthermore, rivaroxaban inhibited the phosphorylation of TAK1 and p65. These data show that rivaroxaban attenuates ALI and inflammation by inhibiting the PAR-2/NF-κB signaling pathway.

Coagulofibrinolytic Changes in Patients with Post-cardiac Arrest Syndrome

Whole-body ischemia and reperfusion due to cardiac arrest and subsequent return of spontaneous circulation constitute post-cardiac arrest syndrome (PCAS), which consists of four syndromes including systemic ischemia/reperfusion responses and post-cardiac arrest brain injury. The major pathophysiologies underlying systemic ischemia/reperfusion responses are systemic inflammatory response syndrome and increased coagulation, leading to disseminated intravascular coagulation (DIC), which clinically manifests as obstruction of microcirculation and multiple organ dysfunction. In particular, thrombotic occlusion in the brain due to DIC, referred to as the "no-reflow phenomenon," may be deeply involved in post-cardiac arrest brain injury, which is the leading cause of mortality in patients with PCAS. Coagulofibrinolytic changes in patients with PCAS are characterized by tissue factor-dependent coagulation, which is accelerated by impaired anticoagulant mechanisms, including antithrombin, protein C, thrombomodulin, and tissue factor pathway inhibitor. Damage-associated molecular patterns (DAMPs) accelerate not only tissue factor-dependent coagulation but also the factor XII- and factor XI-dependent activation of coagulation. Inflammatory cytokines are also involved in these changes via the expression of tissue factor on endothelial cells and monocytes, the inhibition of anticoagulant systems, and the release of neutrophil elastase from neutrophils activated by inflammatory cytokines. Hyperfibrinolysis in the early phase of PCAS is followed by inadequate endogenous fibrinolysis and fibrinolytic shutdown by plasminogen activator inhibitor-1. Moreover, cell-free DNA, which is also a DAMP, plays a pivotal role in the inhibition of fibrinolysis. DIC diagnosis criteria or fibrinolysis markers, including d-dimer and fibrin/fibrinogen degradation products, which are commonly tested in patients and easily accessible, can be used to predict the mortality or neurological outcome of PCAS patients with high accuracy. A number of studies have explored therapy for this unique pathophysiology since the first report on "no-reflow phenomenon" was published roughly 50 years ago. However, the optimum therapeutic strategy focusing on the coagulofibrinolytic changes in cardiac arrest or PCAS patients has not yet been established. The elucidation of more precise pathomechanisms of coagulofibrinolytic changes in PCAS may aid in the development of novel therapeutic targets, leading to an improvement in the outcomes of PCAS patients.

Kaiso protects human umbilical vein endothelial cells against apoptosis by differentially regulating the expression of B-cell CLL/lymphoma 2 family members

Endothelial cell injury can promote the development of various cardiovascular diseases, thus, fully understanding the mechanisms underlying the maintenance of vascular endothelial cell homoeostasis may help prevent and treat cardiovascular disease. Kaiso, a zinc finger and BTB domain containing transcription factor, is key to embryonic development and cancer, but how Kaiso interacts with vascular endothelium is not fully understood. We report that Kaiso has an anti-apoptotic function in human umbilical vein endothelial cells (HUVECs) and human microvascular endothelial cells (HMEC-1s). Overexpression of Kaiso significantly increased cell viability and inhibited hydrogen peroxide-induced apoptosis. Furthermore, Kaiso increased expression of B-cell CLL/lymphoma 2 (BCL2) and reduced expression of BCL2-associated X protein (BAX) and BCL2-interacting killer (BIK) by differentially regulating gene promoter activity. Methylated DNA and specific Kaiso binding site (KBS) contributed to gene regulatory activity of Kaiso. In addition, p120ctn functioned cooperatively in Kaiso-mediated transcriptional regulation.

A Review of Radiation-Induced Coagulopathy and New Findings to Support Potential Prevention Strategies and Treatments

Results from our recent studies have led to the novel hypothesis that radiation-induced coagulopathy (RIC) and associated hemorrhage occurring as part of the acute radiation syndrome (ARS) is a major cause of death resulting from radiation exposure in large mammals, including humans. This article contains information related to RIC, as well as potential strategies for the prevention and treatment of RIC. In addition, new findings are reported here on the occurrence of RIC biomarkers in humans exposed to radiation. To determine whether irradiated humans have RIC biomarkers, blood samples were obtained from radiotherapy patients who received treatment for different types of malignancies. Blood samples from allogeneic hematopoietic cell transplantation (allo-HCT) patients obtained before, during and after irradiation indicated that exposure led to prolonged clot formation times, increased levels of thrombin-antithrombin III (TAT) complex and increased circulating nucleosome/histone (cNH) levels, which suggest potential coagulopathies in the allo-HCT patients. Since these allo-HCT patients received chemotherapy prior to radiotherapy, it is possible that the chemical agents could have influenced the observed results. Frozen plasma samples from radiotherapy patients with prostate, lung and breast cancer were also obtained for analyses of cNH levels. The results indicated that some of these patients had very high cNH blood levels. Analysis of cNH levels in plasma samples from irradiated ferrets also indicated increased cNH levels compared to preirradiation baseline levels. The results from irradiated animals and some radiotherapy patients suggest the possibility that anti-histone antibodies, which block the toxic effects of elevated cNH levels in the blood, might be useful as therapeutic agents for adverse biological radiation-induced effects. The detection of increased levels of cNH in some radiotherapy patient blood samples demonstrates its potential as a biomarker for diagnosing and/or predicting the propensity for developing coagulopathies/hemorrhage, offering possible treatment options with personalized medicine therapies for cancer patients.