Venous Thromboembolism in Sepsis: From Bench to Bedside

Association between platelet count and 30-day in-hospital mortality among intensive care unit patients with sepsis: a multicenter retrospective cohort study

Background

The relationship between platelet count and sepsis outcomes in intensive care units (ICUs) requires comprehensive investigation through large-scale multicenter studies.

Methods

In this multicenter retrospective cohort study, we analyzed 17,977 sepsis patients from 208 U.S. hospitals (2014-2015) using the eICU Collaborative Research Database v2.0. Analyses were adjusted for demographics, clinical parameters, comorbidities, and treatments. Generalized additive models and two-piecewise linear regression were used to assess the relationship between platelet count and mortality.

Results

A U-shaped relationship was identified with an inflection point at 176 × 10⁹/L. Below this threshold, each 10 × 10⁹/L increase in platelet count was associated with a 6% decrease in mortality risk (adjusted OR 0.94, 95% CI 0.93-0.95, p < 0.0001), while above it, each 10 × 10⁹/L increase was associated with a 1% increase in mortality risk (adjusted OR 1.01, 95% CI 1.00-1.01, p = 0.0153).

Conclusion

This large-scale, multicenter retrospective study has made a significant contribution to understanding the association between platelet count and mortality in patients with sepsis in intensive care units. We identified a critical threshold of 176 × 109/L for platelet count and demonstrated a distinct U-shaped relationship with 30-day in-hospital mortality, providing valuable reference criteria for clinical risk stratification.

Recent Advances in Pathogenesis and Anticoagulation Treatment of Sepsis-Induced Coagulopathy

Coagulopathy in sepsis is common and is associated with high mortality. Although immunothrombosis is necessary for infection control, excessive thrombus formation can trigger a systemic thrombo-inflammatory response. Immunothrombosis plays a core role in sepsis-induced coagulopathy, and research has revealed a complex interplay between inflammation and coagulation. Different mechanisms underlying sepsis-related coagulopathy are discussed, including factors contributing to the imbalance of pro- and anticoagulation relevant to endothelial cells. The potential therapeutic implications of anticoagulants on these mechanisms are discussed. This review contributes to our understanding of the pathogenesis of coagulopathy in patients with sepsis. Recent studies suggest that endothelial cells play an important role in immunoregulation and hemostasis. Meanwhile, the non-anticoagulation effects of anticoagulants, especially heparin, which act in the pathogenesis of coagulopathy in septic patients, have been partially revealed. We believe that further insights into the pathogenesis of sepsis-induced coagulopathy will help physicians evaluate patient conditions effectively, leading to advanced early recognition and better decision-making in the treatment of sepsis.

Immunohaemostasis and the significance of immune reactions in the regulation of blood coagulation

Introduction

This study was conducted to determine the specific features of the mutual influence of the immune and haemostatic systems in immunohaemostasis, the role of immune reactions in the regulation of blood coagulation, and the efficacy of modern methods of treating thrombosis and bleeding.

Methods

The study analysed relevant scientific sources on immunology and haematology and identified the specific features of the blood clotting process and the role of immune reactions in it.

Results

The study found that the immune system influences the haematological system through the interaction of blood clotting factors, platelets, plasminogen, endothelial cells with immune cells. The haemostatic system influences the immune system through mechanisms to maintain immune tolerance and immune memory and the properties of clotting factors to activate the stimulation and migration of immune cells to the site of infection. Immune reactions regulate blood coagulation by activating platelets, regulating blood coagulation factors, affecting fibrinolysis, and immune tolerance. The process of platelet activation involves immune cells, immune complexes, and microbial components. The regulation of blood coagulation factors is influenced by the ability of immune cells to produce activators and inhibitors of these factors and to stimulate or slow down fibrinolysis. The immune system's maintenance of immune tolerance to blood components is regulated by mechanisms of immune response suppression, partial immune ignoring of certain blood elements, inhibition of activation of certain immune cells, apoptosis, and selection of immature T-lymphocytes. Treatment methods for patients at risk of thrombosis and bleeding include anticoagulation, antiplatelet, dual antiplatelet therapy, thrombectomy, endovascular methods, medical prophylaxis of bleeding, and coagulation monitoring.

Conclusions

The findings of this study suggest the significance of immune responses in the regulation of blood coagulation processes, and therefore they can be used in the development of immunotherapy methods for the treatment of thrombosis and bleeding.

MicroRNA-181b-5p/HEY2 axis is involved in the progress of deep venous thrombosis via mediating vascular endothelial injury

OBJECTIVES

Deep-venous thrombosis (DVT) refers to abnormal blood clotting in the deep vein cavity, and post-thrombotic syndrome (PTS) is the most frequent complication. The study explored the impact of microRNA 181b-5p on DVT progression based on human umbilical vein endothelial cells (HUVECs).

METHODS

Levels of miR-181b-5p were examined in 150 cases with acute lower extremity DVT. ROC curve and K-M plot were drawn for clinical value assessment. The role of miR-181b-5p in HUVECs viability, migration, apoptosis, inflammatory response and adhesion factors' release was investigated. Target gene of miR-181b-5p was predicted, and its role in cell function was explored.

RESULTS

Low-expressed miR-181b-5p showed favorable diagnostic performance in differentiating DVT with the AUC of 0.948. Patients with low miR-181b-5p had a high incidence of PTS. miR-181b-5p overexpression promoted HUVECs' viability and migration, while inhibiting cell apoptosis and release of inflammatory and adhesion cytokines. As the target gene of miR-181b-5p, HEY2 overexpression reversed the role of miR-181b-5p in HUVECs.

CONCLUSION

MiR-181b-5p serves as a potential biomarker for DVT diagnosis and PTS development. Overexpression of this miRNA targeted HEY2 to alleviate endothelial cell damage.

The subsequent risk of retinal vein occlusion disease after sinusitis diagnosis: a nationwide population-based study

Retinal vein occlusion (RVO) is a common retinal vascular disease that causes visual impairment. However, there is limited evidence regarding the relationship between sinusitis and risk of RVO. This study investigated the association between sinusitis and the subsequent risk of RVO disease. A retrospective cohort study was conducted and patients with sinusitis or RVO were selected from the National Health Insurance Research Database (NHIRD) of Taiwan. In this population-based study, we identified a total of 131,532 sinusitis patients, who were matched with 263,064 non-sinusitis individuals based on sex and age. The Cox proportional hazard regression was applied to demonstrate the adjusted hazard ratio (aHR) with 95% confidence interval (CI) of main outcomes. Our results showed that the crude hazard ratio (cHR) for the risk of RVO was 1.35 (95% CI: 1.20-1.52) in the sinusitis cohort compared with the non-sinusitis cohort. After adjustment for demographics and comorbidities in the multivariable cox regression, the adjusted hazard ratio (aHR) was 1.28 (95% CI: 1.13-1.44). Moreover, statistically significant differences were observed in the 14-year cumulative incidence of RVO (p < 0.0001), central RVO (p = 0.0002), and branch RVO (p = 0.0004) between the sinusitis and non-sinusitis cohorts. In conclusion, our study revealed that patients with sinusitis were at higher risk of being diagnosed with RVO.

Venous thromboembolism: diagnostic advances and unaddressed challenges in management

PURPOSE OF REVIEW

This review summarizes recent advances in developing targeted diagnostics for venous thromboembolism (VTE) and unaddressed knowledge gaps in patient management. Without addressing these critical data needs, the morbidity in VTE patients will persist.

RECENT FINDINGS

Recent studies investigating plasma protein profiles in VTE patients have identified key diagnostic targets to address the currently unmet need for low-cost, confirmatory, point-of-care VTE diagnostics. These studies and a growing body of evidence from animal model studies have revealed the importance of inflammatory and vascular pathology in driving VTE, which are currently unaddressed targets for VTE therapy. To enhance the translation of preclinical animal studies, clinical quantification of thrombus burden and comparative component analyses between modeled VTE and clinical VTE are necessary.

SUMMARY

Lead candidates from protein profiling of VTE patients' plasma offer a promising outlook in developing low cost, confirmatory, point-of-care testing for VTE. Additionally, addressing the critical knowledge gap of quantitatively measuring clinical thrombi will allow for an array of benefits in VTE management and informing the translatability of experimental therapeutics.

Venous Thromboembolism in Burn Patients: A 5-Year Retrospective Study

Background and Objectives: Burn patients manifest all components of Virchow's triad, amplifying the concern for venous thromboembolism (VTE). Routine prophylaxis for VTE remains a subject of debate, with the central concern being the occurrence of associated adverse events. Materials and Methods: We conducted a five-year retrospective study on burn patients admitted to our burn center. Demographic data, comorbidities, burn lesions characteristics, surgical interventions, anticoagulant medication, the need for transfusions, the presence of a central venous catheter, length of stay, complications, and mortality were recorded. Results: Of the overall number of patients (494), 2.63% (13 patients) developed venous thromboembolic complications documented through paraclinical investigations. In 70% of cases, thrombosis occurred in a limb with central venous catether (CVC). Every patient with VTE had a Caprini score above 8, with a mean score of 12 points in our study group. Conclusions: Considering each patient's particularities and burn injury characteristics, individualized approaches may be necessary to optimize thromboprophylaxis effectiveness. We suggest routinely using the Caprini Risk Assessment Model in burn patients. We recommend the administration of pharmacologic thromboprophylaxis in all patients and careful monitoring of patients with Caprini scores above 8, due to the increased risk of VTE. Additionally, ongoing research in this field may provide insights into new strategies for managing thrombotic risk in burn patients.

Ciclopirox mitigates inflammatory response in LPS-induced septic shock via inactivation of SORT1-mediated wnt/β-Catenin signaling pathway

OBJECTIVE

Septic shock, the most severe stage of sepsis, is a deadly inflammatory disorder with high mortality. Ciclopirox (CPX) is a broad-spectrum antimycotic agent which also exerts anti-inflammatory effects in human diseases. However, whether CPX can relieve inflammatory response in LPS-induced septic shock remains unclear.

MATERIALS AND METHODS

Male C57BL/6 mice LPS were injected intraperitoneally with LPS to simulate septic shock in vivo. RAW264.7 cells and bone marrow-derived macrophages (BMDMs) were subject to LPS treatment to simulate septic shock in vitro. ELISA was applied to detect the level of pro-inflammatory cytokines. Cell viability was assessed by CCK-8 assay. Protein levels was detected by western blotting.

RESULTS

CPX enhanced the survival rate and attenuated inflammation in mice with LPS-induced septic shock. Similarly, CPX dose-dependently mitigated LPS-induced inflammation in BMDMs. It was also found that Sortilin 1 (SORT1) was upregulated in both in vivo and in vitro models of LPS-induced septic shock. In addition, SORT1 overexpression counteracted the alleviative effects of CPX on the inflammation response of LPS-challenged BMDMs by activating the Wnt/β-Catenin signaling. Furthermore, BML-284 (a Wnt/β-Catenin agonist) treatment also abrogated CPX-mediated moderation of LPS-triggered inflammatory reaction in BMDMs.

CONCLUSIONS

In sum, we found that CPX protected against LPS-induced septic shock by mitigating inflammation via SORT1-mediated Wnt/β-Catenin signaling pathway.

Heparin, Heparan Sulphate and Sepsis: Potential New Options for Treatment

Sepsis is a life-threatening hyperreaction to infection in which excessive inflammatory and immune responses cause damage to host tissues and organs. The glycosaminoglycan heparan sulphate (HS) is a major component of the cell surface glycocalyx. Cell surface HS modulates several of the mechanisms involved in sepsis such as pathogen interactions with the host cell and neutrophil recruitment and is a target for the pro-inflammatory enzyme heparanase. Heparin, a close structural relative of HS, is used in medicine as a powerful anticoagulant and antithrombotic. Many studies have shown that heparin can influence the course of sepsis-related processes as a result of its structural similarity to HS, including its strong negative charge. The anticoagulant activity of heparin, however, limits its potential in treatment of inflammatory conditions by introducing the risk of bleeding and other adverse side-effects. As the anticoagulant potency of heparin is largely determined by a single well-defined structural feature, it has been possible to develop heparin derivatives and mimetic compounds with reduced anticoagulant activity. Such heparin mimetics may have potential for use as therapeutic agents in the context of sepsis.

Novel Classification of Thrombotic Disorders Based on Molecular Hemostasis and Thrombogenesis Producing Primary and Secondary Phenotypes of Thrombosis

Thrombosis, the common and deadliest disorder among human diseases, develops as a result of the intravascular hemostasis following an intravascular injury, which can be caused by a variety of trauma, non-traumatic insults or clinical illnesses. Thrombosis can occur at any location of the vascular system supplied by blood from the heart to large and smallest arterial and venous systems and may affect the function and anatomy of the organ and tissue. It more commonly occurs in the smaller circulatory system of the vascular tree such as arterioles and capillaries, and venules of the organs, especially in the brain, lungs, heart, pancreas, muscle and kidneys, and sinusoids of the liver. Thrombosis has been referred as the disease of "blood clots", which concept is incompletely defined, but represents many different hemostatic diseases from microthrombosis to fibrin clot disease, macrothrombosis, and combined micro-macrothrombosis. Thrombosis is produced following an intravascular injury via one or more combination of four different mechanisms of thrombogenesis: microthrombogenesis, fibrinogenesis, macrothrombogenesis and micro-macrothrombogenesis initiated by normal physiological hemostasis in vivo. The clinical phenotype expression of thrombosis is determined by: (1) depth of the intravascular wall injury, (2) extent of the injury affecting the vascular tree system, (3) physiological character of the involved vascular system, (4) locality of the vascular injury, and (5) underlying non-hemostatic conditions interacting with hemostasis. Recent acquisition of "two-path unifying theory" of hemostasis and "two-activation theory of the endothelium" has opened a new frontier in science of medicine by identifying the pathophysiological mechanism of different thrombotic disorders and also contributing to the better understanding of many poorly defined human diseases, including different phenotypes of stroke and cardiovascular disease, trauma, sepsis and septic shock, multiorgan dysfunction syndrome, and autoimmune disease, and others. Reviewed are the fundamentals in hemostasis, thrombogenesis and thrombosis based on hemostatic theories, and proposed is a novel classification of thrombotic disorders.