The Coagulant Response in Sepsis

A Nonbactericidal Anionic Antimicrobial Peptide Provides Prophylactic and Therapeutic Efficacies against Bacterial Infections in Mice by Immunomodulatory-Antithrombotic Duality

Although bactericidal cationic antimicrobial peptides (AMPs) have been well characterized, less information is available about the antibacterial properties and mechanisms of action of nonbactericidal AMPs, especially nonbactericidal anionic AMPs. Herein, a novel anionic antimicrobial peptide (Gy-CATH) with a net charge of -4 was identified from the skin of the frog Glyphoglossus yunnanensis. Gy-CATH lacks direct antibacterial effects but exhibits significantly preventive and therapeutic capacities in mice that are infected with Staphylococcus aureus, Enterobacteriaceae coli, methicillin-resistant Staphylococcus aureus (MRSA), or carbapenem-resistant E. coli (CREC). In vitro and in vivo investigations proved the regulation of Gy-CATH on neutrophils and macrophages involved in the host immune defense against infection. Moreover, Gy-CATH significantly reduced the extent of pulmonary fibrin deposition and prevented thrombosis in mice, which was attributed to the regulatory role of Gy-CATH in physiological anticoagulants and platelet aggregation. These findings show that Gy-CATH is a potential candidate for the treatment of bacterial infection.

Association Between Nonthyroidal Illness Syndrome and Disseminated Intravascular Coagulation in Sepsis

Purpose

Both nonthyroidal illness syndrome (NTIS) and disseminated intravascular coagulation (DIC) are commonly occurred in sepsis. The objective of this study is to evaluate the association between NTIS and DIC, as well as their impacts on the mortality in adults with sepsis.

Patients and methods

A total of 1219 septic patients in two Chinese academic centers from October 2012 and October 2022 were enrolled in analysis. We conduct logistic regression models to analyze the independent risk factors for DIC. Modified Poisson regression models are used to estimate the relative risk (RR) of NTIS on the 28 days mortality in septic patients with DIC. Correlation analysis between thyroid function parameters and coagulation parameters is performed with Pearson coefficient be reported.

Results

DIC is diagnosed on 388 (31.8%) of all the 1219 enrolled septic patients within 72 hours after admission. In multivariate logistic regression models, NTIS (OR 3.19; CI 2.31-4.46; p<0.001) is a statistically significant independent risk factor for DIC after adjustment for potential confounders. Twenty-eight days mortality is significantly higher in DIC patients complicated with NTIS compared with the other DIC patients (23.2% vs 14.0%, p=0.024). This result is also robust in different modified Poisson regression models (Model 1: RR 1.46; CI 1.25-1.70; p<0.001; Model 2: RR 1.35; CI 1.14-1.60; p<0.001; Model 3: RR 1.18; CI 1.02-1.37; p=0.026). Correlation analysis reveals that the thyroid function parameters of FT3, FT4 and TSH only have weak correlations with coagulation parameters of platelet count, fibrinogen, FDP, D-dimers, PT, APTT and INR in sepsis.

Conclusion

NTIS is an independent risk factor for DIC in adults with sepsis. DIC patients complicated with NTIS have significantly higher severity and higher rate of mortality.

Oral anticoagulants increased 30-day survival in sepsis patients complicated with atrial fibrillation: a retrospective analysis from MIMIC-IV database

Background

The severity of sepsis is associated with systemic clotting activation. Atrial fibrillation (AF) is the most commonly observed arrhythmia in patients with sepsis and can lead to a poor prognosis. The aim of this study is to elucidate the association between oral anticoagulants and survival from septic patients complicated with AF.

Methods

The data of 8,828 septic patients, including 2,955 AF and 5,873 without AF, were all originated from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients with sepsis and AF are divided into OAC- group (n = 1,774) and OAC+ group (n = 1,181) based on OAC therapy. Septic patients with no AF were considered as the control group (n = 5,873, sepsis and no AF group). The main outcome endpoint was the survival rate of 30 day. The secondary outcome endpoint was the length of stay (LOS) from intensive care unit and hospital. Propensity score matching (PSM) was used to adjust the influence of superfluous factors, and a restricted mean survival time (RMST) analysis was used for calculating the benefit of survival time and survival rate. Analysis including univariate and multivariate logistic regression analysis was conducted to find prognosis-related predictors.

Results

After PSM, the OAC+group had a higher 30-day survival rate compared to the OAC- group (81.59% vs. 58.10%; P < 0.001) in the ICU. Despite the higher survival, the hospital LOS (14.65 days vs. 16.66 days; P = 0.15) and ICU LOS (6.93 days vs. 5.92 days; P = 0.02) were prolonged at OAC+ group than OAC- group. No difference was found in survival rate of 30 day between the sepsis patients using warfarin and patients using NOAC (85.60% vs. 79.84%, P = 0.12). The sepsis patients using warfarin had a prolonged LOS in ICU and hospital compared with the sepsis patients using NOAC. In the vasopressor subgroup, patients who received NOAC therapy were associated with a reduced 30-day survival rate (73.57% vs. 84.03%; P = 0.04) and reduced LOS in ICU and hospital than those on warfarin therapy.

Conclusion

This study demonstrated that oral anticoagulants may increase the 30-day survival rate of patients with sepsis and AF.

Tigecycline treatment causes a decrease in peripheral blood platelet

Tigecycline with broad-spectrum activity against pathogens has advantages in the treatment of severe infections in clinical. Accompany with the huge increase of tigecycline usage, more side effects began to arouse people's attention. The aim of this study was to assess the impact of tigecycline treatment on peripheral blood platelet in patients with severe infections. We retrospectively retrieved demographic and laboratory data in 24 cases of tigecycline-treated patients with severe infections. 18 patients (75%) who were administered tigecycline experienced a decrease in platelet count. The ages of platelet decrease group are significant older than normal group. In the platelet decreased group, the platelet count was significant decreased after 3 days tigecycline treatment. 9 patients' platelet count recovered in 5 days after tigecycline treatment withdraw. Platelet decrease in patient after tigecycline treatment, which can be reversed after tigecycline discontinuation. Tigecycline-induced platelet decrease is associated with age.

Hemostatic disorders in patients with infective endocarditis undergoing urgent surgical valve replacement - Rethinking current beliefs

BACKGROUND

Although infective endocarditis (IE) represents a unique model of thrombo-inflammatory disease, the most frequent early complications of surgical valve replacement (SVR) in IE population are coagulopathy and bleeding. The hemostatic capacity and procedure-related coagulation disorders of IE patients undergoing SVR are unknown. The aims of this study were to test periprocedural hemostasis in IE patients undergoing urgent SVR, and to assess the association between disorders of hemostasis and early bleeding as well as with thromboembolic events.

METHODS

A prospective, two-center, hypothesis generating, observational study was performed between Dec 2017 and Jan 2020. Periprocedural hemostasis of IE patients was assessed using Total Thrombus-formation Analysis System (T-TAS Plus) within 24 h before and 72 h post SVR.

RESULTS

Overall, 25 patients with active IE undergoing urgent SVR were tested. Hemostatic capacity of IE patients was significantly impaired pre-SVR as well as post-SVR compared to normal values, in most aspects of T-TAS assays under high and low shear forces, including prolonged activation of coagulation (T10), final clot formation (OT) and clot strength (AUC30). Post-SVR T-TAS results were significantly associated with early bleeding and with red blood cell, platelet, and fresh frozen plasma administration. No association with thrombo-embolic events was found.

CONCLUSIONS

Patients with active IE undergoing urgent SVR have significantly reduced hemostatic capacity before and after SVR. Hemostatic insufficiency post-SVR is related to bleeding and blood products transfusion. T-TAS may be helpful in assessment of periprocedural hemostasis in patients with IE undergoing SVR.

Decoding Sepsis-Induced Disseminated Intravascular Coagulation: A Comprehensive Review of Existing and Emerging Therapies

Disseminated intravascular coagulation (DIC) is a recurrent complication of sepsis. Since DIC not only promotes organ dysfunction but also represents a strong prognostic factor, it is important to diagnose DIC as early as possible. When coagulation is activated, fibrinolysis is inhibited, blood thinners are consumed, and a condition is created that promotes blood clotting, making it more difficult for the body to remove fibrin or prevent it from being deposited in the blood vessels. This leads to microvascular thrombosis, which plays a role in organ dysfunction. Despite efforts to understand the underlying mechanisms of sepsis-induced DIC, healthcare providers worldwide still face challenges in effectively treating this condition. In this review, we provide an in-depth analysis of the available strategies for sepsis-induced DIC, considering their effectiveness, limitations, and potential for future advances. Corticosteroids (CS), recombinant thrombomodulin (rTM), vitamin C, fibrinolytic therapy, and platelet transfusion are among the treatments discussed in the review. In addition, we are specifically addressing immunomodulatory therapy (IMT) by investigating treatments such as granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon gamma (IFN-γ), and mesenchymal stem cell therapy (MSC). Finally, we also examined how these therapies might affect COVID-19 cases, which often present with sepsis-induced DIC. The review suggests that targeted experiments with randomization are needed to verify the effectiveness of these treatments and to discover novel approaches to treat sepsis-induced DIC. By increasing our knowledge of sepsis-induced DIC, we can develop targeted treatments that have the potential to save lives and improve outcomes.

Plasminogen System in the Pathophysiology of Sepsis: Upcoming Biomarkers

Severe hemostatic disturbances and impaired fibrinolysis occur in sepsis. In the most serious cases, the dysregulation of fibrinolysis contributes to septic shock, disseminated intravascular coagulation (DIC), and death. Therefore, an analysis of circulating concentrations of pro- and anti-fibrinolytic mediators could be a winning strategy in both the diagnosis and the treatment of sepsis. However, the optimal cutoff value, the timing of the measurements, and their combination with coagulation indicators should be further investigated. The purpose of this review is to summarize all relevant publications regarding the role of the main components of the plasminogen activation system (PAS) in the pathophysiology of sepsis. In addition, the clinical value of PAS-associated biomarkers in the diagnosis and the outcomes of patients with septic syndrome will be explored. In particular, experimental and clinical trials performed in emergency departments highlight the validity of soluble urokinase plasminogen activator receptor (suPAR) as a predictive and prognostic biomarker in patients with sepsis. The measurements of PAI-I may also be useful, as its increase is an early manifestation of sepsis and may precede the development of thrombocytopenia. The upcoming years will undoubtedly see progress in the use of PAS-associated laboratory parameters.

Immediate postoperative parenteral anticoagulant therapy in patients with mesenteric ischemia after intestinal resection: a retrospective cohort study at a single institute

BACKGROUND

Bowel gangrene represents a major fatal event in acute mesenteric ischemia. Intestinal resection is inevitable in patients with peritonitis and bowel gangrene. This retrospective study aimed to elucidate the benefit of postoperative parenteral anticoagulation in patients with intestinal resection.

METHODS

Patients with acute mesenteric ischemia and bowel gangrene were recruited retrospectively between January 2007 and December 2019. All patients underwent bowel resection. They were categorized into two groups: patients without immediate parenteral anticoagulant therapy (Group A) and those with immediate parenteral anticoagulant therapy (Group B). Thirty-day mortality and survival were analyzed.

RESULTS

A total of 85 patients were included, with 29 patients in Group A and 56 patients in Group B. Patients in Group B had lower 30-day mortality (16.1%) and a higher 2-year survival rate (45.4%) than patients in Group A (30-day mortality: 51.7%, p = 0.001; 2-year survival rate: 19.0%, p = 0.001). In the 30-day mortality multivariate analysis, patients in Group B had a better outcome (odds ratio = 0.080, 95% confidence interval between 0.011 and 0.605, p = 0.014). Patients in Group B also had a better outcome in the survival multivariate analysis (hazard ratio: 0.435, 95% confidence interval between 0.213 and 0.887, p = 0.022).

CONCLUSIONS

Immediate postoperative parenteral anticoagulant therapy improves prognosis in patients with acute mesenteric ischemia treated by intestinal resection. Trial registration This research was retrospectively approved by the Institutional Review Board (IRB) I&II of Taichung Veterans General Hospital (TCVGH-IRB No.CE21256B) on July 28th, 2021. The informed consent waiver was also approved by IRB I&II of Taichung Veterans General Hospital. The Declaration of Helsinki and ICH-GCP guidelines were followed during this study.

Coagulation Disorders in Sepsis and COVID-19-Two Sides of the Same Coin? A Review of Inflammation-Coagulation Crosstalk in Bacterial Sepsis and COVID-19

Sepsis is a major cause of morbidity and mortality worldwide. Sepsis-associated coagulation disorders are involved in the pathogenesis of multiorgan failure and lead to a subsequently worsening prognosis. Alongside the global impact of the COVID-19 pandemic, a great number of research papers have focused on SARS-CoV-2 pathogenesis and treatment. Significant progress has been made in this regard and coagulation disturbances were once again found to underlie some of the most serious adverse outcomes of SARS-CoV-2 infection, such as acute lung injury and multiorgan dysfunction. In the attempt of untangling the mechanisms behind COVID-19-associated coagulopathy (CAC), a series of similarities with sepsis-induced coagulopathy (SIC) became apparent. Whether they are, in fact, the same disease has not been established yet. The clinical picture of CAC shows the unique feature of an initial phase of intravascular coagulation confined to the respiratory system. Only later on, patients can develop a clinically significant form of systemic coagulopathy, possibly with a consumptive pattern, but, unlike SIC, it is not a key feature. Deepening our understanding of CAC pathogenesis has to remain a major goal for the research community, in order to design and validate accurate definitions and classification criteria.

Fibrinogen Is Associated with Prognosis of Critically Ill Patients with Sepsis: A Study Based on Cox Regression and Propensity Score Matching

Introduction

Sepsis is a common syndrome in critically ill patients. Fibrinogen was reported to be associated with the prognosis of sepsis patients.

Materials and Methods

Data was acquired from Multiparameter Intelligent Monitoring in Intensive Care Database IV (MIMIC-IV) version 1.0. Cox proportional hazards regression was utilized to estimate the relationship between fibrinogen and inhospital mortality. The cumulative incidence of mortality by fibrinogen level was estimated through the Kaplan-Meier curve. Restricted cubic spline (RCS) was used to assess nonlinear relationship. Subgroup analysis was also conducted to evaluate the robustness of the association between fibrinogen and inhospital mortality. Propensity score matching (PSM) was applied to adjust for confounding factors.

Results

A total of 3365 patients, including 2031 survivors and 1334 nonsurvivors, were enrolled in our study. The survivors had a significantly elevated levels of fibrinogen compared with the deceased. The elevated level of fibrinogen was significantly associated with a decrease in mortality in multivariate Cox regression before and after PSM (HR 0.66, P < 0.001 and HR 0.73, P < 0.001, respectively). RCS showed a nearly linear relationship. Subgroup analysis demonstrated the robustness of the association in most subpopulations. However, the association between decreased levels of fibrinogen and increased inhospital mortality was denied after PSM.

Conclusion

The elevated level of fibrinogen hints at better overall survival in critically ill patients with sepsis. Decreased levels of fibrinogen may be of little value in identifying patients with a high risk of death.

Early prophylactic anticoagulation with heparin alleviates mortality in critically ill patients with sepsis: a retrospective analysis from the MIMIC-IV database

Background

Minimal data exist on anticoagulation use and timing and the dose of heparin in patients with sepsis, and whether heparin use improves sepsis survival remains largely unclear. This study was performed to assess whether heparin administration would provide a survival advantage in critically ill patients with sepsis.

Methods

A retrospective cohort study of patients with sepsis in the Medical Information Mart for Intensive Care (MIMIC)-IV database was conducted. Cox proportional hazards model and propensity score matching (PSM) were used to evaluate the outcomes of prophylactic anticoagulation with heparin administered by subcutaneous injection within 48 h of intensive care unit (ICU) admission. The primary outcome was in-hospital mortality. Secondary outcomes included 60-day mortality, length of ICU stay, length of hospital stay and incidence of acute kidney injury (AKI) on day 7. E-Value analysis were used for unmeasured confounding.

Results

A total of 6646 adult septic patients were included and divided into an early prophylactic heparin group (n = 3211) and a nonheparin group (n = 3435). In-hospital mortality in the heparin therapy group was significantly lower than that in the nonheparin group (prematched 14.7 vs 20.0%, hazard ratio (HR) 0.77, 95% confidence interval (CI) [0.68-0.87], p < 0.001, and postmatched 14.9 vs 18.3%, HR 0.78, 95% CI [0.68-0.89], p < 0.001). Secondary endpoints, including 60-day mortality and length of ICU stay, differed between the heparin and nonheparin groups (p < 0.01). Early prophylactic heparin administration was associated with in-hospital mortality among septic patients in different adjusted covariates (HR 0.71-0.78, p < 0.001), and only administration of five doses of heparin was associated with decreased in-hospital mortality after PSM (HR 0.70, 95% CI 0.56-0.87, p < 0.001). Subgroup analysis showed that heparin use was significantly associated with reduced in-hospital mortality in patients with sepsis-induced coagulopathy, septic shock, sequential organ failure assessment score ≥ 10, AKI, mechanical ventilation, gram-positive bacterial infection and gram-negative bacterial infection, with HRs of 0.74, 0.70, 0.58, 0.74, 0.73, 0.64 and 0.72, respectively (p <0.001). E-Value analysis suggested robustness to unmeasured confounding.

Conclusions

This study found an association between early administration prophylactic heparin provided to patients with sepsis and reduced risk-adjusted mortality. A prospective randomized-controlled study should be designed to further assess the relevant findings.

The Dipeptidyl Peptidase-4 Inhibitor Linagliptin Ameliorates Endothelial Inflammation and Microvascular Thrombosis in a Sepsis Mouse Model

The pathophysiology of sepsis involves inflammation and hypercoagulability, which lead to microvascular thrombosis and compromised organ perfusion. Dipeptidyl peptidase (DPP)-4 inhibitors, e.g., linagliptin, are commonly used anti-diabetic drugs known to exert anti-inflammatory effects. However, whether these drugs confer an anti-thrombotic effect that preserves organ perfusion in sepsis remains to be investigated. In the present study, human umbilical vein endothelial cells (HUVECs) were treated with linagliptin to examine its anti-inflammatory and anti-thrombotic effects under tumor necrosis factor (TNF)-α treatment. To validate findings from in vitro experiments and provide in vivo evidence for the identified mechanism, a mouse model of lipopolysaccharide (LPS)-induced systemic inflammatory response syndrome was used, and pulmonary microcirculatory thrombosis was measured. In TNF-α-treated HUVECs and LPS-injected mice, linagliptin suppressed expressions of interleukin-1β (IL-1β) and intercellular adhesion molecule 1 (ICAM-1) via a nuclear factor-κB (NF-κB)–dependent pathway. Linagliptin attenuated tissue factor expression via the Akt/endothelial nitric oxide synthase pathway. In LPS-injected mice, linagliptin pretreatment significantly reduced thrombosis in the pulmonary microcirculation. These anti-inflammatory and anti-thrombotic effects were independent of blood glucose level. Together the present results suggest that linagliptin exerts protective effects against endothelial inflammation and microvascular thrombosis in a mouse model of sepsis.

Neonatal Sepsis and Hemostasis

Neonatal sepsis is considered critical for a significant increase in neonatal morbidity and mortality among hospitalized neonates. Neonatal sepsis, in most cases, coexists with coagulopathy, which can prove to be life-threatening. Complex molecular and cellular systems are involved in the cross-talk between inflammation and hemostasis during sepsis. Disturbances in the regulating systems of the vascular endothelium, and platelet–endothelial and platelet–neutrophil interactions play a pivotal role in both inflammation and coagulation. This complex process is poorly understood in neonates. In addition to the developmental maturation of hemostasis and the immune response in neonatal sepsis, a cellular model of hemostasis during sepsis should be taken into account. This review focused on the molecular and cellular mechanisms underlying inflammation and hemostasis during neonatal sepsis, taking the developmental immune response and developmental hemostasis into account in order to provide future diagnostic approaches to be applied in everyday clinical settings. Regarding the diagnostic modalities, we briefly provide the limitations of the currently used conventional coagulation assays, focusing on viscoelastic tests and platelet flow cytometry.

Coagulation and fibrinolysis balance in disseminated intravascular coagulation

BACKGROUND

Sepsis is a common underlying disease associated with disseminated intravascular coagulation (DIC). We have recently determined hemostatic pathological states at diagnosis through simultaneous assessment of coagulation and fibrinolysis potentials in sepsis-associated DIC using clot-fibrinolysis waveform analysis. Here we aimed to investigate hemostatic pathological states, focusing on the balance between coagulation and fibrinolysis dynamics during the clinical course in pediatric sepsis-associated DIC.

METHODS

Coagulation and fibrinolysis potential functions in three pediatric patients with sepsis-associated DIC during their clinical course were quantified using clot-fibrinolysis waveform analysis. A maximum coagulation velocity (|min1|) and maximum fibrinolysis velocity (|FL-min1|) was calculated as a ratio relative to normal plasma.

RESULTS

In case 1, coagulation-enhanced and fibrinolysis-depressed state (|min1|-ratio 2.22 and |FL-min1|-ratio 0.42) was observed on day 1. This discrepancy significantly reduced after anticoagulant therapy and plasma exchange on day 2. A well-balanced hemostatic state (0.70 and 0.62, respectively) was restored on day 7. In case 2, fibrinolysis-impaired state (|min1|-ratio 1.09 and |FL-min1|-ratio 0.21) was seen on day 1. The |min1| ratio was slightly prolonged and the |FL-min1| ratio was severely decreased. Both were restored on day 7 and returned to normal levels on day 12. In case 3, twofold coagulation- and fibrinolysis-enhanced states (|min1|-ratio 1.99 and |FL-min1|-ratio 1.11) were seen on day 1. However, both potentials rapidly decreased on day 2 (0.49 and 0.0, respectively). She died on day 5.

CONCLUSIONS

The hemostatic pathological states in sepsis-associated DIC depend on disease progression. Comprehensive assessment of coagulation-fibrinolysis potentials over time may therefore be helpful in considering optimal treatment plans for sepsis-associated DIC.

Coagulopathy and sepsis: Pathophysiology, clinical manifestations and treatment

Sepsis is a complex syndrome with a high incidence, increasing by 8.7% annually over the last 20 years. Coagulopathy is a leading factor associated with mortality in patients with sepsis and range from slight thrombocytopenia to fatal disorders, such as disseminated intravascular coagulation (DIC). Platelet reactivity increases during sepsis but prospective trials of antiplatelet therapy during sepsis have been disappointing. Thrombocytopenia is a known predictor of worse prognosis during sepsis. The mechanisms underlying thrombocytopenia in sepsis have yet to be fully understood but likely involves decreased platelet production, platelet sequestration and increased consumption. DIC is an acquired thrombohemorrhagic syndrome, resulting in intravascular fibrin formation, microangiopathic thrombosis, and subsequent depletion of coagulation factors and platelets. DIC can be resolved with treatment of the underlying disorder, which is considered the cornerstone in the management of this syndrome. This review presents the current knowledge on the pathophysiology, diagnosis, and treatment of sepsis-associated coagulopathies.

Hypocoagulable Tendency on Thromboelastometry Associated With Severity and Anticoagulation Timing in Pediatric Septic Shock: A Prospective Observational Study

Objective: To identify whether coagulation profiles using thromboelastometry are associated with outcomes in pediatric septic shock. The primary outcomes were the development of disseminated intravascular coagulation (DIC) and the severity of the pediatric intensive care unit (PICU) existing scoring systems, while the secondary outcome was hospital mortality. This study aimed to contribute to current findings of the limitations of conventional tests in determining the optimal timing of anticoagulation in sepsis. Design: A prospective, observational study conducted between August 2019 and August 2020. Setting: PICU at a pediatric tertiary hospital in Hanoi, Vietnam. Patients: Fifty-five pediatric patients who met the septic shock criteria were enrolled. Measurements and Main Results: Fifty-five patients with septic shock were recruited. At the time of diagnosis, thromboelastometry revealed normocoagulability, hypercoagulability, and hypocoagulability in 29, 29, and 42% of the patients, respectively (p > 0.05); however, most patients in the overt DIC and non-survival groups progressed to hypocoagulability (82 and 64%, respectively). The overt DIC, PELOD-2 > 8, PRISM-III > 11, and non-survival group had a significant hypocoagulable tendency according to thromboelastometry parameters [prolonged clotting time (CT) and clot formation time (CFT); and reduced α-angle (α), maximum clot firmness (MCF), thrombodynamic potential index (TPI)] compared to the non-overt DIC, PELOD-2 ≤ 8, PRISM-III score ≤ 11 and survival group (p < 0.05). Conventional parameters between the normocoagulable and hypercoagulable groups were not different (p > 0.05). Hypocoagulability was characterized by lower platelet count and fibrinogen level, higher prolonged prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (APTT), and higher D-dimer level than in hypercoagulability (p < 0.05). Hypocoagulable tendency on thromboelastometry had a higher hazard at a PT > 16.1 s [area under the curve (AUC) = 0.747, odds ratio (OR) = 10.5, p = 0.002], INR > 1.4 (AUC = 0.754, OR = 6.9, p = 0.001), fibrinogen <3.3 g/L (AUC = 0.728, OR = 9.9, p = 0.004), and D-dimer > 3,863 ng/mL (AUC = 0.728, OR = 6.7, p = 0.004). Conclusions: Hypocoagulable tendency using thromboelastometry is associated with the severity of septic shock. Conventional coagulation tests may fail to detect hypercoagulability, which is crucial in determining anticoagulation timing.

COVID-19 associated coagulopathy in critically ill patients: A hypercoagulable state demonstrated by parameters of haemostasis and clot waveform analysis

Patients with COVID-19 are known to be at risk of developing both venous, arterial and microvascular thrombosis, due to an excessive immuno-thrombogenic response to the SARS-CoV-2 infection. Overlapping syndromes of COVID-19 associated coagulopathy with consumptive coagulopathy and microangiopathy can be seen in critically ill patients as well. Blood was collected from 12 Intensive Care Unit (ICU) patients with severe COVID-19 who were on either mechanical ventilation or on high flow oxygen with a PaO2/FiO2 ratio of <300 mmHg. Laboratory tests were performed for parameters of haemostasis, clot waveform analysis and anti-phospholipid antibodies. CWA parameters were raised with elevated aPTT median Min1 (clot velocity) 9.3%/s (IQR 7.1–9.9%/s), elevated PT median Min1 10.3%/s (IQR 7.1–11.1%/s), elevated aPTT median Min2 (clot acceleration) 1.5%/s² (IQR 1.0–1.6%/s²), elevated PT median Min2 5.2%/s² (3.6–5.7%/s²), elevated aPTT median Max2 (clot deceleration) 1.3%/s² (IQR 0.8–1.4%/s²) elevated PT median Max2 3.8%/s² (IQR 2.6–4.2%/s²), increased aPTT median Delta change (decreased light transmission due to increased clot formation) 87.8% (IQR 70.2–91.8%) and PT median Delta change 33.0%. This together with raised median Factor VIII levels of 262.5%, hyperfibrinogenemia (median fibrinogen levels 7.5 g/L), increased median von Willebrand factor antigen levels 320% and elevated median D-dimer levels 1.7 μg/dl support the diagnosis of COVID-19 associated coagulopathy. A lupus anticoagulant was present in 50% of patients. Our laboratory findings further support the view that severe SARS-CoV-2 infection is associated with a state of hypercoagulability.

PECAM-1 protects against DIC by dampening inflammatory responses via inhibiting macrophage pyroptosis and restoring vascular barrier integrity

Disseminated intravascular coagulation (DIC) is a frequent complication of sepsis that affects patient outcomes due to accompanying thrombo-inflammation and microvascular permeability changes. Platelet endothelial cell adhesion molecule-1 (PECAM-1), a cellular adhesion and signaling receptor that is expressed on both hematopoietic and endothelial cells, plays an important anti-inflammatory role in acute and chronic inflammatory disease models. Little is known, however, about role and mechanism of PECAM-1 in septic DIC. Here, we investigated whether PECAM-1 might play a protective role in hindering the development of septic DIC. Plasma levels of soluble PECAM-1 were markedly elevated in septic patients that developed DIC, with a correspondingly poorer outcome. PECAM-1 knockout exhibited more severe DIC and poorer outcome in the LPS induced- and cecal ligation and puncture-induced DIC model, which could be alleviated by tissue factor inhibitor. This phenomenon seemed to be equally linked to PECAM-1 expression by both endothelial and blood cells. Furthermore, PECAM-1 was found to exert its protective effect on developing septic DIC by the following 2 distinct mechanisms: the inhibition of macrophage pyroptosis and the acceleration of the restoration of the endothelial cell barrier. Taken together, these results implicate PECAM-1 as a potentially attractive target for the development of novel therapeutics to manage and treat septic DIC.

Effect of a Recombinant Human Soluble Thrombomodulin on Baseline Coagulation Biomarker Levels and Mortality Outcome in Patients With Sepsis-Associated Coagulopathy

OBJECTIVES

To assess the effects of recombinant human soluble thrombomodulin treatment on 28-day all-cause mortality in subgroups categorized by baseline coagulation biomarker levels (prothrombin fragment 1.2, thrombin-antithrombin complex, D-dimer) in patients with sepsis-associated coagulopathy in the Sepsis Coagulopathy Asahi Recombinant LE Thrombomodulin trial (SCARLET) (NCT01598831).

DESIGN

Post hoc, subgroup analysis of a randomized, double-blind, placebo-controlled, multinational, multicenter phase 3 study.

SETTING

ICUs at 159 sites in 26 countries.

PATIENTS

Eight-hundred adults with sepsis-associated coagulopathy defined as international normalized ratio greater than 1.40 and platelet count between 30 × 10/L and 150 × 10/L or greater than 30% decrease within 24 hours with concomitant cardiovascular and/or respiratory failure.

INTERVENTIONS

Patients randomized and treated with recombinant human soluble thrombomodulin (0.06 mg/kg/d; n = 395) or equivalent placebo (n = 405) for 6 days.

MEASUREMENTS AND MAIN RESULTS

Recombinant human soluble thrombomodulin did not significantly reduce 28-day all-cause mortality in the Sepsis Coagulopathy Asahi Recombinant LE Thrombomodulin trial: absolute risk reduction was 2.55% (p = 0.32) in patients with sepsis-associated coagulopathy. In this post hoc analysis, mortality steadily increased with increasing baseline prothrombin fragment 1.2 and thrombin-antithrombin complex levels in the placebo group; for those values exceeding the upper limit of normal, the mortality increases in the recombinant human soluble thrombomodulin group were lower or negligible with increasing baseline prothrombin fragment 1.2 and thrombin-antithrombin complex. Consequently, absolute risk reductions were greater in subgroups with higher baseline prothrombin fragment 1.2 or thrombin-antithrombin complex. Absolute risk reductions were also greater in subgroups with baseline coagulation biomarker levels at or above median of the entire study population, ranging from 4.2% (95% CI, -5.0% to 13.4%) to 5.5% (95% CI, -4.0% to 14.9%).

CONCLUSIONS

Compared with patients receiving placebo, patients treated with recombinant human soluble thrombomodulin having higher baseline thrombin generation biomarker levels had lower mortality. Further research regarding the predictive role of coagulation biomarkers for recombinant human soluble thrombomodulin treatment response in sepsis-associated coagulopathy is warranted to evaluate clinical relevance.

Evaluation of coagulation function by rotation thromboelastometry in critically ill patients with severe COVID-19 pneumonia

Critically ill patients with COVID-19 pneumonia suffered both high thrombotic and bleeding risk. The effect of SARS-CoV-2 on coagulation and fibrinolysis is not well known. We conducted a retrospective study of critically ill patients admitted to an intensive care unit (ICU) a cause of severe COVID-19 pneumonia and we evaluated coagulation function using rotational thromboelastometry (ROTEM) on day of admission (T0) and 5 (T5) and 10 (T10) days after admission to ICU. Coagulation standard parameters were also evaluated. Forty patients were enrolled into the study. The ICU and the hospital mortality were 10% and 12.5%, respectively. On ICU admission, prothrombin time was slightly reduced and it increased significantly at T10 (T0 = 65.1 ± 9.8 vs T10 = 85.7 ± 1.5, p = 0.002), while activated partial thromboplastin time and fibrinogen values were higher at T0 than T10 (32.2 ± 2.9 vs 27.2 ± 2.1, p = 0.017 and 895.1 ± 110 vs 332.5 ± 50, p = 0.002, respectively); moreover, whole blood thromboelastometry profiles were consistent with hypercoagulability characterized by an acceleration of the propagation phase of blood clot formation [i.e., CFT below the lower limit in INTEM 16/40 patients (40%) and EXTEM 20/40 patients (50%)] and significant higher clot strength [MCF above the upper limit in INTEM 20/40 patients (50%), in EXTEM 28/40 patients (70%) and in FIBTEM 29/40 patients (72.5%)]; however, this hypercoagulable state persists in the first five days, but it decreases ten day after, without returning to normal values. No sign of secondary hyperfibrinolysis or sepsis induced coagulopathy (SIC) were found during the study period. In six patients (15%) a deep vein thrombosis and in 2 patients (5%) a thromboembolic event, were found; 12 patients (30%) had a catheter-related thrombosis. ROTEM analysis confirms that patients with severe COVID-19 pneumonia had a hypercoagulation state that persisted over time.

Lung transplantation using argatroban in severe heparin-induced thrombocytopenia during extracorporeal membrane oxygenation: a case series

Lung transplantation during heparin-induced thrombocytopenia (HIT) is controversial and often considered a contraindication because of the risk of increased bleeding and thrombosis in the recipient. Although lung transplantation offers the best chance for cure in end-stage lung disease, the outcome after transplantation is still controversial in patients with HIT. In our center, two patients developed HIT type II during venovenous extracorporeal membrane oxygenation (ECMO) support for acute respiratory failure. They underwent successful lung transplantation using argatroban. The subsequent clinical course was uneventful except evacuation of post-operative hematoma in 1 patient, and they were discharged. Argatroban was successfully used during lung transplant surgery in patients who developed HIT type II during ECMO support. Further studies on the feasibility and safety of lung transplantation using a direct thrombin inhibitor in patients with HIT during ECMO are required.

Cell-free chromatin particles released from dying host cells are global instigators of endotoxin sepsis in mice

We have earlier reported that cell-free chromatin (cfCh) particles that are released from dying cells, or those that circulate blood, can readily enter into healthy cells, illegitimately integrate into their genomes and induce dsDNA breaks, apoptosis and intense activation of inflammatory cytokines. We hypothesized that sepsis is caused by cfCh released from dying host cells following microbial infection leading to bystander host cell apoptosis and inflammation which are perpetuated in a vicious cycle with release of more cfCh from dying host cells. To test this hypothesis we used three cfCh inactivating agents namely 1) anti-histone antibody complexed nanoparticles which inactivate cfCh by binding to histones; 2) DNase I which inactivates cfCh by degrading its DNA component, and 3) a novel pro-oxidant combination of Resveratrol and Copper which, like DNase I, inactivates cfCh by degrading its DNA component. Female C57 BL/6 mice, 6–8 weeks old, were administered a single i.p. injection of LPS at a dose of 10 mg/Kg or 20 mg/Kg with or without concurrent treatment with the above cfCh inactivating agents. Administration of cfCh inactivating agents concurrently with LPS resulted in prevention of following pathological parameters: 1) release of cfCh in extra-cellular spaces of brain, lung and heart and in circulation; 2) release of inflammatory cytokines in circulation; 3) activation of DNA damage, apoptosis and inflammation in cells of thymus, spleen and in PBMCs; 4) DNA damage, apoptosis and inflammation in cells of lung, liver, heart, brain, kidney and small intestine; 5) liver and kidney dysfunction and elevation of serum lactate; 6) coagulopathy, fibrinolysis and thrombocytopenia; 7) lethality. We conclude that cfCh that are released from dying host cells in response to bacterial endotoxin represents a global instigator of sepsis. cfCh inactivation may provide a novel approach to management of sepsis in humans.

Crosstalk between Platelet and Bacteria: A Therapeutic Prospect

Platelets are typically recognized for their roles in the maintenance of hemostasis and vascular wall repair to reduce blood loss. Beyond hemostasis, platelets also play a critical role in pathophysiological conditions like atherosclerosis, stroke, thrombosis, and infections. During infection, platelets interact directly and indirectly with bacteria through a wide range of cellular and molecular mechanisms. Platelet surface receptors such as GPIbα, FcγRIIA, GPIIbIIIa, and TLRs, etc. facilitate direct interaction with bacterial cells. Besides, the indirect interaction between platelet and bacteria involves host plasma proteins such as von Willebrand Factor (vWF), fibronectin, IgG, and fibrinogen. Bacterial cells induce platelet activation, aggregation, and thrombus formation in the microvasculature. The activated platelets induce the Neutrophil Extracellular Traps (NETs) formation, which further contribute to thrombosis. Thus, platelets are extensively anticipated as vital immune modulator cells during infection, which may further lead to cardiovascular complications. In this review, we cover the interaction mechanisms between platelets and bacteria that may lead to the development of thrombotic disorders. Platelet receptors and other host molecules involved in such interactions can be used to develop new therapeutic strategies to combat against infection-induced cardiovascular complications. In addition, we highlight other receptor and enzyme targets that may further reduce infection-induced platelet activation and various pathological conditions.

Role of inherited thrombophilic profile on survival of patients with sepsis

The existence of various coagulation and/or fibrinolytic system disorders (such as inherited thrombophilia) in patients with sepsis could possibly modify host response to infection as well as patient outcome. The aim of the study is to investigate inherited thrombophilic profile in patients with sepsis. Eighty-three patients with sepsis admitted at the Department of Internal Medicine of the University General Hospital of Patras, Greece were included. Thrombophilic profile (factor V G1691A (Leiden), factor V H1299R (R2), prothrombin G20210A, MTHFR C677T, MTHFR A1298C, factor XIII V34L, β-fibrinogen-455 G-A and plasminogen activator inhibitor (PAI)-1 4G/5G) was evaluated using the cardiovascular diseases (CVD) StripAssay based on DNA isolation, PCR and reverse hybridisation. Data were collected from patients' chart reviews. Seventy patients (84.3%) of the 83 enrolled had at least one thrombophilic mutation. The most common mutations were heterozygous for β-fibrinogen-455 G-A (43.4%), heterozygous for factor XIII V34L (32.5%), PAI-1 4G/4G (26.5%), homozygous MTHFR C677T (22.9%), heterozygous factor V H1299R (R2) (13.3%) and homozygous MTHFR A1298C (12.0%). A 30-day mortality was 14.5%. Multivariate analysis revealed that mortality was independently associated with Simplified Acute Physiology Score II score on admission, pneumonia and fibrinogen on admission. Nine patients (10.8%) developed septic shock. Coagulation disorders on admission, bacteraemia and PAI-1 genotype 5G/5G were independently associated with development of septic shock. The presence of thrombophilic mutations in patients with sepsis may affect their clinical response, and future studies are needed in order to elucidate the role of isolated thrombophilic mutations in patients with sepsis or septic shock.

Fluid resuscitation with 0.9% saline alters haemostasis in an ovine model of endotoxemic shock

INTRODUCTION

Fluid resuscitation is a cornerstone of severe sepsis management, however there are many uncertainties surrounding the type and volume of fluid that is administered. The entire spectrum of coagulopathies can be seen in sepsis, from asymptomatic aberrations to fulminant disseminated intravascular coagulation (DIC). The aim of this study was to determine if fluid resuscitation with saline contributes to the haemostatic derangements in an ovine model of endotoxemic shock.

MATERIALS AND METHODS

Twenty-one adult female sheep were randomly divided into no endotoxemia (n = 5) or endotoxemia groups (n = 16) with an escalating dose of lipopolysaccharide (LPS) up to 4 μg/kg/h administered to achieve a mean arterial pressure below 60 mmHg. Endotoxemia sheep received either no bolus fluid resuscitation (n = 8) or a 0.9% saline bolus (40 mL/kg over 60 min) (n = 8). No endotoxemia, saline only animals (n = 5) underwent fluid resuscitation with a 0.9% bolus of saline as detailed above. Hemodynamic support with vasopressors was initiated if needed, to maintain a mean arterial pressure (MAP) of 60-65 mm Hg in all the groups.

RESULTS

Rotational thromboelastometry (ROTEM®) and conventional coagulation biomarker tests demonstrated sepsis induced derangements to secondary haemostasis. This effect was exacerbated by saline fluid resuscitation, with low pH (p = 0.036), delayed clot initiation and formation together with deficiencies in naturally occurring anti-coagulants antithrombin (p = 0.027) and Protein C (p = 0.001).

CONCLUSIONS

Endotoxemia impairs secondary haemostasis and induces changes in the intrinsic, extrinsic and anti-coagulant pathways. These changes to haemostasis are exacerbated following resuscitation with 0.9% saline, a commonly used crystalloid in clinical settings.

Angiopoietin 2 Levels in the Risk Stratification and Mortality Outcome Prediction of Sepsis-Associated Coagulopathy

It has been well established that angiopoietin 2 (Ang-2), a glycoprotein involved in activation of the endothelium, plays an integral role in the pathophysiology of sepsis and many other inflammatory conditions. However, the role of Ang-2 in sepsis-associated coagulopathy (SAC) specifically has not been defined. The aim of this study was to measure Ang-2 plasma levels in patients with sepsis and suspected disseminated intravascular coagulation (DIC) in order to demonstrate its predictive value in SAC severity determination and 28-day mortality outcome. Plasma samples were collected from 102 patients with sepsis and suspected DIC at intensive care unit (ICU) admission. The Ang-2 plasma levels were quantified using a sandwich enzyme-linked immunosorbent assay method. The International Society on Thrombosis and Haemostasis DIC scoring system was used to compare the accuracy of Ang-2 levels versus clinical illness severity scores in predicting SAC severity. Mean Ang-2 levels in patients with sepsis and DIC were significantly higher in comparison to healthy controls (P < 0.0001), and median Ang-2 levels showed a downward trend over time (P = 0.0008). Baseline Ang-2 levels and clinical illness severity scores were higher with increasing severity of disease, and Ang-2 was a better predictor of DIC severity than clinical illness scores. This study demonstrates that Ang-2 levels are significantly upregulated in SAC, and this biomarker can be used to risk stratify patients with sepsis into non-overt DIC and overt DIC. Furthermore, the Ang-2 level at ICU admission in a patient with sepsis and suspected DIC may provide a predictive biomarker for mortality outcome.

Prediction of bleeding and thrombosis by standard biochemical coagulation variables in haematological intensive care patients

PURPOSE

We assessed the value of standard biochemical coagulation parameters in predicting bleeding, thrombosis and mortality in adult Intensive Care Unit (ICU) patients with haematological malignancies.

METHODS

We screened all patients with acute leukaemia and myelodysplastic syndrome admitted to a university hospital ICU during 2008-2012. Data were obtained from the clinical chemistry laboratory database and patient files. We graded bleeding according to the World Health Organisation (WHO)-system within 24-h, within 5-days and during the whole ICU stay. We analysed the predictive values of laboratory parameters using multiple logistic regression and receiver operator characteristics (ROC) curves. As we previously have established that platelet count at admission was associated with bleeding, we focused on International Normalised Ratio (INR), activated pro-thrombin time (APTT), anti-thrombin, D-dimer and fibrinogen, and markers of infection (C-reactive protein, pro-calcitonin), kidney function (creatinine) and tissue damage (lactate dehydrogenase (LDH)).

RESULTS

We included 116 patients; 66 (57%) had at least one bleeding episode and 11 (9%) patients had at least one thrombotic event. The differences in coagulation values when bleeding compared to baseline values were minor. INR was the only variable we found associated with subsequent bleeding within 24 h from admission to ICU (odds ratio 2.91, 95% CI: 1.01-8.43, P = 0.048). ROC analyses did not show predictive value of any of the other variables with regards to bleeding and none of the variables were associated with thrombosis in adjusted analyses. Increased levels of LDH at admission were associated with increased 7-day and 30-day mortality.

CONCLUSIONS

Increased INR at admission was associated with a higher rate of bleeding in ICU patients with haematological malignancies. No other biochemical coagulation or other parameter had any association with bleeding, thrombosis or mortality except increased LDH, which at ICU admission was associated with increased 30-day mortality.

Sepsis induced by cecal ligation and perforation (CLP) alters nucleotidase activities in platelets of rats

Sepsis is a potentially lethal condition, and it is associated with platelet alterations. The present study sought to investigate the activity of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), E-5'-nucleotidase, and ecto-adenosine deaminase (E-ADA) in the platelets of rats that were induced with sepsis. Male Wistar rats were divided into three groups of ten animals each: a negative control group (normal; NC); a group that underwent surgical procedures (sham); and a group that underwent cecal ligation and perforation (CLP). The induction of sepsis was confirmed by bacteremia, and the causative pathogen identified was Escherichia coli. Hematological parameters showed leukocytosis and thrombocytopenia in animals in the septic group. The results also revealed that there were significant (p < 0.05) increases in adenosine triphosphate (ATP) and adenosine monophosphate (AMP) hydrolyses, and in the deamination of adenosine in the CLP group compared to the sham and control groups. Conversely, ADP hydrolysis was significantly decreased (p < 0.05) in the CLP group compared to the sham and control groups. Purine levels were analyzed by high-performance liquid chromatography (HPLC) in serum samples from control, sham, and CLP groups. Increased concentrations of ATP, adenosine, and inosine were found in the CLP group compared to the sham and control groups. Conversely, the concentrations of ADP and AMP in the CPL group were not significantly altered. We suggest that alterations in hematological parameters, nucleotide hydrolysis in platelets, and nucleotide concentrations in serum samples of rats with induced sepsis may be related to thromboembolic events.

The role of heparin in sepsis: much more than just an anticoagulant

Despite progress in antibiotic treatment, mechanical ventilation, fluid resuscitation and blood glucose maintenance, sepsis remains a cause of high mortality in the intensive care unit to date, there are no proven treatment strategies for the routine management of septic patients. The extensive interaction between inflammation and coagulation contributes to the basic pathophysiology of sepsis. Thus, the agents that attenuate the activation of both inflammation and coagulation may improve the outcome in sepsis. Apart from the well-known anticoagulant effects of heparin, it also possesses various immunomodulatory properties and protects glycocalyx from shedding. Hence, heparin seems to be such an agent. Immunothrombosis plays an important role in early host defence against bacterial dissemination, thus the proper timing for anticoagulant therapy should be determined. We review the available experimental and clinical data supporting the use of heparin in sepsis. At this time the use of heparin in the treatment of sepsis is conflicting. Future trials of heparin therapy for sepsis should concentrate on the very severely ill patients, in whom benefit is most likely to be demonstrated.

Severity of anemia and hemostatic parameters are strong predictors of outcome in postoperative neurosurgical patients

Objective:

Post-operative neurosurgical patients are commonly associated with haemostatic derangements; many a times leading to development of overt disseminated intravascular coagulation (DIC) and eventually death in some of them. The present study has analysed the factors that would predict the outcome in post operative neurosurgical patients with deranged haemostatic parameters.

Methods:

This is a prospective, descriptive study over a period of 15 months on 115 post operative neurosurgical patients who were clinically suspected to have DIC and investigated for the haemostatic parameters. Patients with at least one parameter abnormal were included in the study and complete data was available in 85 patients was analysed.

Results:

Majority of deaths (22/33, 66.7%) were related to bleeding and end organ failure attributed to DIC. The most common haemostatic abnormalities found were thrombocytopenia with prolonged Prothrombin time (PT) in 48/115 (42.7%) patients. The parameters found significantly different between those who survived and those died were age, post-operative development of chest infections, severe anemia, and renal function abnormalities. Also, patient outcome correlated strongly with marked prolongation of prothrombin time (PT) and Partial thromboplastin time (PTT). However, presence of ≥3 coagulation abnormalities, presence of significant drop in haemoglobin post operatively and /or development of chest infection predicted death in postoperative neurosurgical patients with accuracy of 80.4% and this was highly significant (P = 0.000).

Conclusion:

Presence of ≥3 coagulation abnormalities, significant drop in hemoglobin post operatively and /or development of chest infection post-operatively were strong predictors of death in postoperative neurosurgical patients.

Recognition and Management of Hemostatic Disorders in Critically Ill Patients Needing to Undergo an Invasive Procedure

Abnormal laboratory coagulation test results are frequently documented in critically ill patients, and these patients often also need to undergo invasive procedures. Clinicians have an understandable desire to minimize any perceived heightened risk of bleeding complications in those patients who require invasive procedures. In this setting, prophylactic administration of platelets or plasma is commonplace. This review explores the nature of these sequential statements and the degree to which these statements are supported by evidence. We discuss the complexity of managing the low risk of procedure-related bleeding in a setting where coagulation tests fail to reliably predict this risk. The role of prophylactic transfusion of platelets and plasma and correction of medication-induced coagulopathy is also reviewed. New strategies are required to improve the evidence base, including novel methodological approaches or the use of a clinical scoring system.

Impact of thrombosis on pulmonary endothelial injury and repair following sepsis

The prevailing morbidity and mortality in sepsis are largely due to multiple organ dysfunction (MOD), most commonly lung injury, as well as renal and cardiac dysfunction. Despite recent advances in defining many aspects of the pathogenesis of sepsis-related MOD, including acute respiratory distress syndrome (ARDS), there are currently no effective pharmacological or cell-based treatments for the disease. Human and animal studies have shown that pulmonary thrombosis is common in sepsis-induced ARDS, and preclinical studies have shown that anticoagulation may improve outcome following sepsis challenge. The potential beneficial effect of anticoagulation on outcome is unconvincing in clinical studies, however, and these discrepancies may arise from the multiple and sometimes opposing actions of thrombosis on the pulmonary endothelium following sepsis. It has been suggested, for example, that mild pulmonary thrombosis prevents escape of bacterial infection into the circulation, while severe thrombosis causes hypoxia and results in pulmonary endothelial damage. Evidence from both human and animal studies has demonstrated the key role of microvascular leakage in determining the outcome of sepsis. In this review, we describe thrombosis-dependent mechanisms that regulate pulmonary endothelial injury and repair following sepsis, including activation of the coagulation cascade by tissue factor and stimulation of vascular repair by hypoxia-inducible factors. Targeting such mechanisms through anticoagulant, anti-inflammatory, and reparative methods may represent a novel approach for the treatment of septic patients.

Changing Definitions of Sepsis

Sepsis is one of the main causes of morbidity and mortality in critically ill patients despite the use of modern antibiotics and resuscitation therapies. Outcomes in sepsis have improved overall, probably because of an enhanced focus on early diagnosis and other improvements in supportive care, but mortality rates still remain unacceptably high. The diagnosis and definition of sepsis is a critical problem due to the heterogeneity of this disease process. Although it is apparent that much more needs to be done to advance our understanding, sepsis and related terms remain difficult to define. A 1991 consensus conference developed initial definitions that systemic inflammatory response syndrome (SIRS) to infection would be called sepsis. Definitions of sepsis and septic shock were revised in 2001 to incorporate the threshold values for organ damage. In early 2016, the new definitions of sepsis and septic shock have changed dramatically. Sepsis is now defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. The consensus document describes organ dysfunction as an acute increase in total Sequential Organ Failure Assessment (SOFA) score two points consequently to the infection. A significant change in the new definitions is the elimination of any mention of SIRS. The Sepsis-3 Task Force also introduced a new bedside index, called the qSOFA, to identify outside of critical care units patients with suspected infection who are likely to develop sepsis. Recently updated the consensus definitions improved specificity compared with the previous descriptions.

Coagulation and sepsis

Severe sepsis is almost invariably associated with systemic activation of coagulation. There is ample evidence that demonstrates a wide-ranging cross-talk between hemostasis and inflammation, which is probably implicated in the pathogenesis of organ dysfunction in patients with sepsis. Inflammation not only leads to initiation and propagation of coagulation activity, but coagulation also markedly influences inflammation. Molecular mechanisms that play a role in inflammation-induced effects on coagulation have been recognized in much detail. Pro-inflammatory cells and cyto- and chemokines can activate the coagulation system and downregulate crucial physiological anticoagulant mechanisms. Initiation of coagulation activation and consequent thrombin generation is caused by expression of tissue factor on activated monocytes and endothelial cells 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 (PAI-1). Increased fibrin generation and impaired break down lead to deposition of (micro)vascular clots, which may contribute to tissue ischemia and ensuing organ dysfunction. The foundation of the management of coagulation in sepsis is the explicit and thorough treatment of the underlying disorder by antibiotic treatment and source control measures. Adjunctive strategies focused at the impairment of coagulation, including anticoagulants and restoration of physiological anticoagulant mechanisms, may supposedly be indicated and have been found advantageous in experimental and initial clinical trials.

Modulation of Interleukins in Sepsis-Associated Clotting Disorders: Interplay With Hemostatic Derangement

Interleukins play a central role in the immune system and are involved in a variety of immunological, inflammatory, and infectious disease states including sepsis syndrome. Levels of interleukins may correlate with overall survival and may directly or indirectly affect some of the regulators of coagulation and fibrinolysis, thereby disrupting hemostasis and thrombosis. Our hypothesis is that in sepsis-associated coagulopathies (SACs), interleukins may be upregulated, leading to hemostatic imbalance by generating thrombogenic mediators. We profiled the levels of interleukins IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, and IL-10 in addition to d-dimer (DD) in patients with SAC and in normal donors. We observed the highest increase in interleukins IL-6 (322-fold), IL-8 (48-fold), IL-10 (72-fold), and DD (18-fold). This suggests that interleukins such as IL-6 and IL-10 have a close association with coagulopathy and fibrinolytic dysregulation in sepsis and can be considered as candidates for potential therapeutic targets in SAC.

The coagulopathy of acute sepsis

PURPOSE OF REVIEW

Sepsis, defined by the presence of infection and host inflammation, is a lethal clinical syndrome with an increasing mortality rate worldwide. In severe disease, the coagulation system becomes diffusely activated, with consumption of multiple clotting factors resulting in disseminated intravascular coagulation (DIC). When present, DIC portends a higher mortality rate. Understanding the mechanisms that tie inflammation and diffuse thrombosis will allow therapeutic interventions to be developed. The coagulopathy of acute sepsis is a dynamic process that is time and disease burden specific. Whole-blood testing of coagulation may provide more clinically useful information than the classical tests. Natural anticoagulants that regulate thrombosis are downregulated in sepsis. Patients may benefit from the modulation of the coagulation system when systemic inflammation and hypercoagulopathy exist. Proper timing of anticoagulant therapy may ultimately lead to decreased incidence of multisystem organ dysfunction.

RECENT FINDINGS

The pathogenesis of coagulopathy in sepsis is driven by an upregulation of procoagulant mechanisms and simultaneous downregulation of natural anticoagulants. Inflammation caused by the invading organism is a natural host defense that cannot be eliminated during treatment. Successful strategies to prevent multisystem organ dysfunction center on stratifying patients at high risk for DIC and restoring the balance of inflammation and coagulation.

SUMMARY

The prevention of DIC in septic patients is a key therapeutic target in preventing death from multisystem organ failure. Stratifying patients for therapy using thromboelastometry, specific markers for DIC, and composite scoring systems is an area of growing research.

Catastrophic APS in the context of other thrombotic microangiopathies

The catastrophic antiphospholipid syndrome (CAPS) is a rare disease that affects 1 % of cases with antiphospholipid syndrome (APS). CAPS can mimic or overlap with different thrombotic diseases; many patients present with a microthrombotic storm or thrombotic microangiopathic hemolytic anemia (TMHA). Thus, the differential diagnosis of CAPS includes thrombotic thrombocytopenic purpura (TTP), typical and atypical hemolytic uremic syndrome (HUS), systemic infections, malignancies, pregnancy-related disorders, malignant hypertension, heparin-induced thrombocytopenia, and drug-induced thrombotic microangiopathies. Antiphospholipid antibody (aPL) positivity has been proposed as the clue in this differential diagnosis; however, aPL can also occur in healthy people and in those with infections or malignancies. Thus, the differential diagnosis of an aPL-positive patient presenting with a microthrombotic storm is broad; the workup should include a special attention to signs of infection and disseminated malignant disease, assessing the funduscopic signs of malignant hypertension, testing ADAMTS13 activity and anti-heparin-platelet factor 4 (HPF4) antibodies, and searching previous exposure to certain drugs. This article aims to review the main diseases included in the differential diagnosis of CAPS in the context of other thrombotic microangiopathies.

Diagnostic and prognostic utility of tissue factor for severe sepsis and sepsis-induced acute lung injury

Background

Tissue factor (TF) and tissue factor pathway inhibitor (TFPI) play a central role in the endothelial permeability regulation and dysfunction, which is associated with the development of sepsis and acute lung injury/acute respiratory distress syndrome (ALI/ARDS). The aim of this study is to assess the diagnostic and prognostic values of TF and TFPI in patients with sepsis and sepsis-induced ARDS.

Methods

A total of 62 patients with sepsis, 167 patients with severe sepsis and 32 healthy volunteers were enrolled in this prospective observational study. TF and TFPI levels were measured by enzyme-linked immunosorbent assay (ELISA).

Results

Patients with sepsis-induced ARDS showed significantly higher median levels of TF compared with patients without ARDS (1425.5 (1019.9 to 2595.2) pg/ml vs 916.2 (724.1 to 1618.2) pg/ml, P < 0.001), and compared with sepsis patients (943.5 (786.4 to 992.4) pg/ml, P < 0.001) on the day of admission. However, there was no significant difference between sepsis patients and healthy subjects, or between septic shock and non-septic shock patients (P > 0.05). The AUC of TF for the diagnosis of sepsis-induced ARDS was 0.749 (95% confidence interval (CI) 0.675-0.822). Plasma TF levels in the non-survivors of severe sepsis were significantly higher than those of survivors (1618.6 (1017.1 to 2900.8) pg/ml vs. 979.9 (757.2 to 1645.5) pg/ml, P < 0.001), and multivariate logistic regression showed the plasma value of TF was the independent predictor for 30-day mortality in patients with severe sepsis (P = 0.0022, odds ratio (OR) = 1.41, 95% CI 1.24-1.69). The AUC of TF for predicting 30-day mortality in severe sepsis patients was 0.718 (95% CI 0.641-0.794). However, there was no significant difference in the plasma TFPI values among the healthy control, sepsis and severe sepsis groups (P > 0.05).

Conclusions

Our data showed that tissue factor is a valuable diagnostic biomarker for the diagnosis of sepsis-induced ARDS. Moreover, tissue factor is a strong prognostic marker for short-term mortality in severe sepsis and sepsis-induced ARDS patients.

Platelets and infections - complex interactions with bacteria

Platelets can be considered sentinels of vascular system due to their high number in the circulation and to the range of functional immunoreceptors they express. Platelets express a wide range of potential bacterial receptors, including complement receptors, FcγRII, Toll-like receptors but also integrins conventionally described in the hemostatic response, such as GPIIb–IIIa or GPIb. Bacteria bind these receptors either directly, or indirectly via fibrinogen, fibronectin, the first complement C1q, the von Willebrand Factor, etc. The fate of platelet-bound bacteria is questioned. Several studies reported the ability of activated platelets to internalize bacteria such as Staphylococcus aureus or Porphyromonas gingivalis, though there is no clue on what happens thereafter. Are they sheltered from the immune system in the cytoplasm of platelets or are they lysed? Indeed, while the presence of phagolysosome has not been demonstrated in platelets, they contain antimicrobial peptides that were shown to be efficient on S. aureus. Besides, the fact that bacteria can bind to platelets via receptors involved in hemostasis suggests that they may induce aggregation; this has indeed been described for Streptococcus sanguinis, S. epidermidis, or C. pneumoniae. On the other hand, platelets are able to display an inflammatory response to an infectious triggering. We, and others, have shown that platelet release soluble immunomodulatory factors upon stimulation by bacterial components. Moreover, interactions between bacteria and platelets are not limited to only these two partners. Indeed, platelets are also essential for the formation of neutrophil extracellular traps by neutrophils, resulting in bacterial clearance by trapping bacteria and concentrating antibacterial factors but in enhancing thrombosis. In conclusion, the platelet–bacteria interplay is a complex game; its fine analysis is complicated by the fact that the inflammatory component adds to the aggregation response.

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

Endothelial cells are highly active, sensing and responding to signals from extracellular environments. They act as gatekeepers, mediating the recruitment and extravasation of proinflammatory leukocytes to the sites of tissue damage or infection. Endothelial cells participate in fibrinolysis by secreting tissue-type plasminogen activator, which converts plasminogen to active enzyme plasmin through constitutive and regulated pathways. Fibrinolysis systems and inflammation are tightly linked, as both responses are major host defense systems against both healing processes of tissue repair as well as pathogenic microorganisms. Endothelial cell dysfunction is one of the early signs of systemic inflammation, and it is a trigger of multiple organ failure in sepsis. The marked increase in plasminogen activator inhibitor-1 level causes fibrinolytic shutdown in endotoxemia or sepsis and is one of the most important predictors of multiple organ dysfunction during sepsis-induced disseminated intravascular coagulation (DIC). Leukocytes exhibit the first-line response to microorganisms. Leukocyte-derived elastase degrades cross-linked fibrin to yield molecular species distinct from those generated by plasmin. The alternative systems for fibrinolysis that interact with the plasminogen activator-plasmin systems may play crucial roles in the lysis of fibrin clots in sepsis-induced DIC.

Histone deacetylase III as a potential therapeutic target for the treatment of lethal sepsis

BACKGROUND

We have recently demonstrated that inhibition of histone deacetylase (HDAC) Class I, II, and IV with nonspecific HDAC inhibitors improves survival in a mouse model of lethal cecal ligation and puncture (CLP). However, the consequence of HDAC Class III inhibition is unknown in this model. The aims of the present study were to explore the effect of EX-527, a selective Sirtuin 1 (SIRT1) inhibitor, on survival in the lethal model of CLP-sepsis and to assess the impact of the treatment on inflammatory cytokine production, coagulopathy, and bone marrow atrophy during severe sepsis.

METHODS

For Experiment I, C57BL/6J mice were subjected to CLP and, 1 hour later, intraperitoneally injected with either EX-527 dissolved in dimethyl sulfoxide (DMSO) or DMSO only. Survival was monitored for 10 days. For Experiment II, 1 hour after CLP animals were randomly treated with (1) DMSO vehicle and (2) EX-527. Peritoneal fluid and blood samples were collected for measurement of cytokines, and blood was also used to evaluate coagulation status using thrombelastography. In addition, long bones (femurs and tibias) were examined to determine morphologic changes in the marrow by hematoxylin and eosin staining. For Experiment III, normal primary splenocytes were cultured and treated with lipopolysaccharide in the presence or absence of EX-527 to assess cytokine production.

RESULTS

EX-527 significantly improved survival (50% vs. 0% survival as compared to vehicle, p = 0.0007) and attenuated levels of cytokines tumor necrosis factor α and interleukin 6 in the blood and the peritoneal fluid compared with the vehicle control. It also decreased tumor necrosis factor α and interleukin 6 production by splenocytes in vitro. Selective inhibition of SIRT1 was associated with significant improvements in fibrin cross-linkage, platelet function, and clot rigidity but had no significant impact on the clot initiation parameters. Moreover, inhibition of SIRT1 was associated with a significant decrease in bone marrow atrophy.

CONCLUSION

Selective inhibition of Class III HDAC SIRT1 significantly improves survival, attenuates cytokine levels and sepsis-associated coagulopathy, and decreases bone marrow atrophy in a lethal mouse septic model.

The

The addition of the word “catastrophic” to the term antiphospholipid syndrome (APS) was proposed 20 years ago by Ronald Asherson when he published an editorial in The Journal of Rheumatology describing a group of patients who develop multiple thrombosis in a short period of time and with a much worse prognosis than that attributed to patients with classic APS [1]. Since then, many cases have been published reporting patients with this devastating variant of the APS.

Clinical significance of platelet-associated hematological parameters as an early supplementary diagnostic tool for sepsis in thrombocytopenic very-low-birth-weight infants

Sepsis is an important cause of death in very-low-birth-weight (VLBW) neonates. Although conventional diagnostic indicator of sepsis has been done by blood cultures, this took much longer time. The measurement of platelet-associated parameters such as mean platelet volume (MPV) and platelet distribution width (PDW) become more reliable and accurate parameters as a non-specific marker for sepsis. Our objective is to examine the usefulness of those platelet hematological parameters as a supplementary diagnostic tool for sepsis in VLBW infants. This study is a retrospective cohort study of neonates subject to the diagnosis of sepsis from October 2006 to July 2010. This study was conducted at Korea University medical center. We studied total 2,336 infants for 32 days from birth (Day 0) to Day 31. We compared three groups of infants to examine differences of platelet parameters according to their age from birth to Day 31: (i) full-terms versus VLBW without sepsis, (ii) VLBW without sepsis versus VLBW with sepsis and (iii) thrombocytopenic VLBW without sepsis versus those with sepsis. The platelet-associated parameters were significantly distinguishable between septic and non-septic groups at their early age (∼ 1 week), especially platelet counts (PLT) (p = 0.0091), MPV (p = 0.007) and PDW (p = 0.0372) in thrombocytopenic VLBW infants. The decreased PLT, elevated MPV and PDW were major characteristics of septic group. We suggested maximum cutoff values of the platelet factors by performing receiver operating characteristic curve analysis between septic and non-septic thrombocytopenic VLBW infants, among which MPV was the most promising index (AUCMPV = 0.7044 > AUCPLT = 0.6921 > AUCPDW = 0.6593). Platelet-associated hematological parameters are useful for the early diagnosis of sepsis as a more efficient and supplementary diagnostic method in thrombocytopenic VLBW infants.

Is the neutrophil a 'prima donna' in the procoagulant process during sepsis?

Activation of the coagulation system is a fundamental host defense mechanism. Microorganisms that have invaded the body are trapped and disposed of in clots. Monocytes/macrophages are widely accepted as the main players in the procoagulant process; however, recent evidence suggests that neutrophils also play important roles. Tissue factor, which initiates the extrinsic coagulation cascade, is reportedly expressed on the surface of neutrophils, as well as on microparticles derived from neutrophils. Neutrophil extracellular traps (NETs) are another source of tissue factor. The components of NETs, such as DNA, histones, and granule proteins, also provide procoagulant activities. For instance, DNA initiates the intrinsic pathway, histones are a strong generator of thrombin, and granule proteins such as neutrophil elastase, cathepsin G and myeloperoxidase contribute to the suppression of the anticoagulation systems. Although understanding of the mechanisms that are involved in coagulation/fibrinolysis in sepsis has gradually progressed, the impact of neutrophils on thrombogenicity during sepsis remains to be addressed. Since the importance of the connection between coagulation and inflammation is advocated nowadays, further research on neutrophils is required.