Venous thrombosis

mRNA vaccination reduces the thrombotic possibility in COVID-19: Inflammation risk estimates

Thrombosis is a common clinical feature associated with morbidity and mortality in coronavirus disease-2019 (COVID-19) patients. Cytokine storm in COVID-19 increases patients' systemic inflammation, which can cause multiple health consequences. In this work, we aimed to indicate the effect of Pfizer-BioNTech vaccination on the modulation of monocyte chemoattractant protein-3 (MCP-3), matrix metalloproteinase 1 (MMP-1), and tumor necrosis factor-alpha (TNF-α) levels, and other systemic inflammatory biomarkers that associates with COVID-19 severity in patients who suffers from thrombosis consequences. For this purpose, ninety people were collected from Ibn Al-Nafees Hospital and divided into three groups each of which contained 30 people, 15 of them were venous thromboembolism (VTE) positive and the other were VTE negative. The three groups were non-vaccinated COVID-19, vaccinated COVID-19, and control. The levels of MCP-3 and TNF-α were significantly (p < 0.05) increased in vaccinated and non-vaccinated COVID-19 patients regardless of their thrombosis condition, while MMP-1 level was non-significantly (p > 0.05) higher in vaccinated patients compared to control. MCP-3 and TNF-α were correlated positively with D-dimer (r = 0.544 and r = 0.513, respectively) in non-vaccinated patients, while MMP-1 and TNF-α were correlated positively with D-dimer (r = 0.624 and r = 0.575, respectively) in vaccinated patients. The odds ratio of MCP-3 (2.252), MMP-1 (1.062), and TNF-α (1.360) were reduced in vaccinated patients (2.093, 1.022, and 1.301 for MCP-3, MMP-1, and TNF-α respectively). Thus, MCP-3 plays a vital role in COVID-19 pathophysiology, and vaccination can reduce the risk of developing VTE in COVID-19 patients, and improve the inflammatory condition of patients.

Identification of oxylipins and lipid mediators in pulmonary embolism

BACKGROUND

This study aimed to investigate the role of oxylipins and lipid mediators in Pulmonary Embolism (PE), a serious cardiovascular condition associated with high morbidity and mortality rates.

METHODS

A total of 6,365 hospitalized patients with thrombosis and 200 healthy individuals were recruited as the control group from 2015 to 2023. Thrombus type, coagulation, and lipid-related parameters were statistically analysed. Additionally, lipidomic characteristics of serum samples from the PE and control groups were examined via LC-MS/MS for the first time.

RESULTS

Among the 6,365 hospitalized patients with thrombosis, 72.1% (4,587/6,365) had venous thromboembolism (VTE). Within the VTE group, the incidence of PE was 12.1% (555/4,587). In comparison to the healthy control (HC) group, the PE group exhibited significant elevations in coagulation-related parameters, such as factor VIII (F VIII) and von Willebrand factor (vWF) activities, while antithrombin III (AT III) and factor XII (F XII) activities were notably reduced. Lipid-related parameters, including serum cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A (apoA), were significant reductions in PE patients (P < 0.0001), with areas under the curve (AUCs) exceeding 0.9. LC-MS/MS analysis of serum samples revealed 118 oxidized lipid metabolites. Compared to the HC group, the PE group exhibited 10 upregulated oxidized lipid metabolites, with the most significant difference observed in 20-hydroxyPGF2α derived from arachidonic acid (ARA). The study identified upregulated oxidized lipid metabolites primarily linked to the ARA metabolism signalling pathway.

CONCLUSION

This research indicates a notable correlation between lipid metabolism and the occurrence and development of PE. Specifically, upregulation of the arachidonic acid metabolism signalling pathway may be an important pathogenic factor for PE, and 20-hydroxyPGF2α derived from ARA has potential as a biomarker for PE disease.

Platelet integrin αIIbβ3 plays a key role in a venous thrombogenesis mouse model

Venous thrombosis (VT) is a common vascular disease associated with reduced survival and a high recurrence rate. VT is initiated by the accumulation of platelets and neutrophils at sites of endothelial cell activation. A role for platelet αIIbβ3 in VT is not established, a task complicated by the increased bleeding risk caused by partial agonists such as tirofiban. Here, we show that m-tirofiban, a modified version of tirofiban, does not agonize αIIbβ3 based on lack of neoepitope expression and the cryo-EM structure of m-tirofiban/full-length αIIbβ3 complex. m-tirofiban abolishes agonist-induced platelet aggregation while preserving clot retraction ex vivo and, unlike tirofiban, it suppresses venous thrombogenesis in a mouse model without increasing bleeding. These findings establish a key role for αIIbβ3 in VT initiation and suggest that m-tirofiban and compounds with a similar structurally-defined mechanism of action merit consideration as potential thromboprophylaxis agents in patients at high risk for VT and hemorrhage.

Neutrophil extracellular traps in homeostasis and disease

Neutrophil extracellular traps (NETs), crucial in immune defense mechanisms, are renowned for their propensity to expel decondensed chromatin embedded with inflammatory proteins. Our comprehension of NETs in pathogen clearance, immune regulation and disease pathogenesis, has grown significantly in recent years. NETs are not only pivotal in the context of infections but also exhibit significant involvement in sterile inflammation. Evidence suggests that excessive accumulation of NETs can result in vessel occlusion, tissue damage, and prolonged inflammatory responses, thereby contributing to the progression and exacerbation of various pathological states. Nevertheless, NETs exhibit dual functionalities in certain pathological contexts. While NETs may act as autoantigens, aggregated NET complexes can function as inflammatory mediators by degrading proinflammatory cytokines and chemokines. The delineation of molecules and signaling pathways governing NET formation aids in refining our appreciation of NETs' role in immune homeostasis, inflammation, autoimmune diseases, metabolic dysregulation, and cancer. In this comprehensive review, we delve into the multifaceted roles of NETs in both homeostasis and disease, whilst discussing their potential as therapeutic targets. Our aim is to enhance the understanding of the intricate functions of NETs across the spectrum from physiology to pathology.

A single-center study of reference intervals for TAT, PIC, TM and t-PAIC in healthy older Chinese adults

OBJECTIVE

To explore the distribution of thrombin-antithrombin complex (TAT), plasmin-α2-antiplasmin inhibitor complex (PIC), thrombomodulin (TM), and tissue plasminogen activator-inhibitor complex (t-PAIC) in healthy older Chinese adults, and establish the reference intervals (RIs).

METHODS

The Biotech Shine i2900 chemiluminescence immune assay was used to measure the plasma concentrations of TAT, PIC, TM, and t-PAIC in 1628 adults ≥ 60 years. The RIs were established using the 2.5th and 97.5th percentiles of the distribution.

RESULTS

TAT levels were lower in males than females across all ages. Differences between the ages of 60-79 and ≥ 80 in both sex groups were statistically significant, with an upward trend with age. PIC levels showed no difference between the sexes but increased with age in both groups. TM levels did not differ between the sex groups, with slight fluctuation with age. The level in females aged 60-69 was slightly higher than that in the other groups; the difference was statistically significant. T-PAIC levels were not significantly different between the sex groups, with less fluctuation with sex and age. The level in males ≥ 80 years old was slightly lower than that in the other groups; the difference was statistically significant. The RIs for all markers in healthy older Chinese adults were determined and statistically reported by age and sex. For TAT, the RIs for males aged 60-79 and ≥ 80 are 0.51-2.30 ng/mL and 0.88-3.72 ng/mL, respectively, whereas for females aged 60-79 and ≥ 80, the RIs are 0.68-2.82 ng/mL and 1.02-3.67 ng/mL, respectively. For PIC, the RIs for the age groups 60-69, 70-79, and ≥ 80 are 0.10-0.89 µg/mL, 0.12-1.00 µg/mL, and 0.21-1.04 µg/mL, respectively. The RI of TM for females aged 60-69 is 3.32-13.22 TU/mL, whereas it is 2.96-13.26 TU/mL for the other groups. The RI of t-PAIC for males aged ≥ 80 is 1.63-10.68 ng/mL, whereas it is 2.33-11.34 ng/mL for the other groups.

CONCLUSIONS

Discrepancies exist in thrombus markers among different sex and age groups. The RIs of TAT, PIC, TM and t-PAIC for healthy older Chinese adults were successfully established.

Enhanced venous thrombosis and hypercoagulability in murine and human metabolic dysfunction-associated steatohepatitis

BACKGROUND

Patients with metabolic dysfunction-associated steatohepatitis (MASH) are at an increased risk of developing venous thromboembolic events, including deep vein thrombosis (DVT). To date, the study of DVT in MASH has been hampered by the lack of reliable models that mimic the pathologic aspects of human disease.

OBJECTIVES

To evaluate DVT severity and hypercoagulability in murine and human MASH.

METHODS

Transcriptional changes in the liver, plasma markers of coagulation, and DVT severity were evaluated in mice fed a standard chow diet or a high-fructose, high-fat, and high-cholesterol MASH diet for 24 weeks. Plasma analyses of coagulation markers and thrombin generation assays were performed in a well-characterized cohort of patients with or without MASH.

RESULTS

Mice fed the MASH diet developed steatohepatitis and fibrosis, mimicking human MASH. Liver RNA sequencing revealed a significant upregulation of pathways related to inflammation and coagulation concomitant with increased levels of plasma coagulation markers including increased prothrombin fragment 1+2, thrombin-antithrombin complex, plasminogen activator inhibitor-1 levels, and endothelin 1. MASH exacerbated DVT severity in mice, as evidenced by increased thrombus weight and higher thrombosis incidence (15/15 vs 11/15 in controls, P = .0317). Higher endothelin 1 release and increased apoptosis were found in endothelial cells stimulated with supernatants of palmitate-stimulated HepG2 cells. Patients with MASH exhibited increased levels of plasma coagulation markers and delayed thrombin generation.

CONCLUSION

We report enhanced DVT severity and hypercoagulability, both in murine and human MASH. Our model of MASH-DVT can facilitate a better understanding of the fundamental mechanisms leading to increased venous thromboembolic events in patients with MASH.

Targeting Fibrinolytic Inhibition for Venous Thromboembolism Treatment: Overview of an Emerging Therapeutic Approach

Venous thrombosis and pulmonary embolism (venous thromboembolism) are important causes of morbidity and mortality worldwide. In patients with venous thromboembolism, thrombi obstruct blood vessels and resist physiological dissolution (fibrinolysis), which can be life threatening and cause chronic complications. Plasminogen activator therapy, which was developed >50 years ago, is effective in dissolving thrombi but has unacceptable bleeding risks. Safe dissolution of thrombi in patients with venous thromboembolism has been elusive despite multiple innovations in plasminogen activator design and catheter-based therapy. Evidence now suggests that fibrinolysis is rigidly controlled by endogenous fibrinolysis inhibitors, including α2-antiplasmin, plasminogen activator inhibitor-1, and thrombin-activable fibrinolysis inhibitor. Elevated levels of these fibrinolysis inhibitors are associated with an increased risk of venous thromboembolism in humans. New therapeutic paradigms suggest that accelerated and effective fibrinolysis may be achieved safely by therapeutically targeting these fibrinolytic inhibitors in venous thromboembolism. In this article, we discuss the role of fibrinolytic components in venous thromboembolism and the current status of research and development targeting fibrinolysis inhibitors.

Integrated landscape of plasma metabolism and proteome of patients with post-traumatic deep vein thrombosis

Deep vein thrombosis (DVT) is a leading cause of morbidity and mortality after trauma. Here, we integrate plasma metabolomics and proteomics to evaluate the metabolic alterations and their function in up to 680 individuals with and without DVT after trauma (pt-DVT). We identify 28 metabolites and 2 clinical parameter clusters associated with pt-DVT. Then, we develop a panel of 9 metabolites (hexadecanedioic acid, pyruvic acid, L-Carnitine, serotonin, PE(P-18:1(11Z)/18:2(9Z,12Z)), 3-Hydroxycapric acid, 5,6-DHET, 3-Methoxybenzenepropanoic acid and pentanenitrile) that can predict pt-DVT with high performance, which can be verified in an independent cohort. Furthermore, the integration analysis of metabolomics and proteomics data indicates that the upregulation of glycolysis/gluconeogenesis-TCA cycle may promote thrombosis by regulating ROS levels in red blood cells, suggesting that interfering with this process might be potential therapeutic strategies for pt-DVT. Together, our study comprehensively delineates the metabolic and hematological dysregulations for pt-DVT, and provides potential biomarkers for early detection.

Platelets in Thrombosis and Atherosclerosis: A Double-Edged Sword

This review focuses on the dual role of platelets in atherosclerosis and thrombosis, exploring their involvement in inflammation, angiogenesis, and plaque formation, as well as their hemostatic and prothrombotic functions. Beyond their thrombotic functions, platelets engage in complex interactions with diverse cell types, influencing disease resolution and progression. The contribution of platelet degranulation helps in the formation of atheromatous plaque, whereas the reciprocal interaction with monocytes adds complexity. Alterations in platelet membrane receptors and signaling cascades contribute to advanced atherosclerosis, culminating in atherothrombotic events. Understanding these multifaceted roles of platelets will lead to the development of targeted antiplatelet strategies for effective cardiovascular disease prevention and treatment. Understanding platelet functions in atherosclerosis and atherothrombosis at different stages of disease will be critical for designing targeted treatments and medications to prevent or cure the disease Through this understanding, platelets can be targeted at specific times in the atherosclerosis process, possibly preventing the development of atherothrombosis.

Efficacy and safety of aspirin in venous thromboembolism prevention after total hip arthroplasty, total knee arthroplasty or fracture

Background: This study aims to analyse the efficacy and safety of aspirin in the prevention of venous thromboembolism (VTE) for patients undergoing total hip arthroplasty (THA), total knee arthroplasty (TKA) or fracture. Patients and methods: Two independent investigators searched PubMed, Embase, Cochrane and ClinicalTrials.gov from January 2000 to June 2023 to retrieve randomized control trials (RCTs) about aspirin in VTE prevention after arthroplasty or fracture. Then, the relative risk (RR) was utilized to evaluate its efficiency and safety. Results: A total of 16 RCTs with 27,864 patients were included. There was no statistical difference in the incidence of deep-vein thrombosis (RR: 1.31, p = 0.100), pulmonary embolism (RR:1.05, p = 0.850), VTE (RR:1.28, p = 0.290), major bleeding (RR:0.96, p = 0.900), and death (RR:1.01, p = 0.960) between the aspirin group and the anticoagulants group. Subgroup analysis showed that a relatively higher incidence of deep-vein thrombosis in patients undergoing TKA (RR:1.49, p = 0.030), fracture (RR:1.48, p = 0.001), patients receiving 81 mg aspirin twice daily (RR:1.48, p = 0.001) and patients from North America (RR:1.57, p<0.001) when comparing aspirin with anticoagulants. Meanwhile, the incidence of VTE was higher in patients receiving 100 mg aspirin once daily (RR:1.82, p<0.001) compared with anticoagulants. Additionally, the incidence of all bleeding (RR:2.00, p = 0.030) was higher in patients receiving aspirin in Asia compared with anticoagulants. Conclusions: In terms of clinical effectiveness and safety, aspirin (antiplatelet agent) was generally not inferior to anticoagulants in the prevention of VTE after THA, TKA, or fracture. Notably, the clinical effectiveness of aspirin was affected by different surgical types, the doses of aspirin and races.

Thrombotic events associated with immune checkpoint inhibitors and novel antithrombotic strategies to mitigate bleeding risk

Although immunotherapy is expanding treatment options for cancer patients, the prognosis of advanced cancer remains poor, and these patients must contend with both cancers and cancer-related thrombotic events. In particular, immune checkpoint inhibitors are associated with an increased risk of atherosclerotic thrombotic events. Given the fundamental role of platelets in atherothrombosis, co-administration of antiplatelet agents is always indicated. Platelets are also involved in all steps of cancer progression. Classical antithrombotic drugs can cause inevitable hemorrhagic side effects due to blocking integrin β3 bidirectional signaling, which regulates simultaneously thrombosis and hemostasis. Meanwhile, many promising new targets are emerging with minimal bleeding risk and desirable anti-tumor effects. This review will focus on the issue of thrombosis during immune checkpoint inhibitor treatment and the role of platelet activation in cancer progression as well as explore the mechanisms by which novel antiplatelet therapies may exert both antithrombotic and antitumor effects without excessive bleeding risk.

Role of Platelets and Their Interaction with Immune Cells in Venous Thromboembolism

Venous thromboembolism (VTE) represents a significant global health challenge, ranking as the third leading cause of cardiovascular-related mortality. VTE pervades diverse clinical specialties, posing substantial risks to patient well-being and imposing considerable economic strains on health care systems. While platelets have long been recognized as pivotal players in hemostasis, emerging evidence underscores their multifaceted immune functions and their capacity to engage in crosstalk with other immune cells, such as neutrophils, thereby fostering immune-related thrombosis. Notably, investigations have elucidated the pivotal role of platelets in the pathogenesis of VTE. This review provides a comprehensive overview of platelet physiology, encompassing their activation, secretion dynamics, and implications in VTE. Moreover, it delineates the impact of platelet interactions with various immune cells on the initiation and progression of VTE, explores the correlation between platelet-related laboratory markers and VTE, and elucidates the role of platelets in thrombosis regression.

Rates and Impact of Serious Adverse Events after Endovascular Thrombectomy among Large Vessel Occlusion Stroke Patients

OBJECTIVE

Complications or serious adverse events (SAEs) are common in the treatment of patients with large vessel occlusion stroke. There has been limited study of the impact of SAEs for patients after endovascular thrombectomy (EVT). The goal of this study was to characterize the rates and clinical impact of SAEs following EVT.

METHODS

A post hoc analysis was performed using pooled databases of the "DEVT" and "RESCUE BT" trials. SAEs were designated as symptomatic intracranial hemorrhage, brain herniation or craniectomy, respiratory failure, circulatory failure, pneumonia, deep venous thrombosis, and systemic bleeding. The primary endpoint was functional independence (modified Rankin scale score 0-2 within 90 days). Logistic regression analysis was used to determine the predictors and associations between SAEs and outcomes.

RESULTS

Of 1,182 enrolled patients, 402 (34%) had a procedural complication and 745 (63%) had 1,404 SAE occurrences with 4.65% in-hospital mortality. The three most frequent SAEs were pneumonia (620, 52.5%), systemic bleeding (174, 14.7%), and respiratory failure (173, 14.6%). Pneumonia, systemic bleeding, or deep venous thrombosis was less life-threatening. Patients with advanced age (adjusted odds ratio, 1.28 [95% confidence interval, 1.14-1.43]), higher NIHSS (1.09 [1.06-1.11]), occlusion site (middle cerebral artery-M1 vs. internal carotid artery [ICA]: 0.75 [0.53-1.04]; M2 vs. ICA: 1.30 [0.80-2.12]), longer procedure time (1.01 [1.00-1.01]), and unsuccessful vessel recanalization (1.79 [1.06-2.94]) were more likely to experience SAEs. Compared with no SAE, patients with SAEs had lower odds of functional independence (0.46 [0.40-0.54]).

CONCLUSIONS

Overall, SAEs diagnosed following thrombectomy in patients with stroke were common (more than 60%) and associated with functional dependence. Patients with advanced age, higher NIHSS, longer procedure time, and failed recanalization were more likely to experience SAEs. There was no statistical difference in the risk of SAEs among patients with M1 and M2 occluded compared with those ICA occluded. An understanding of the prevalence and predictors of SAEs could alert clinicians to the estimated risk of an SAE for a patient after EVT.

ET1 acts as a potential plasma biomarker and therapeutic target in deep venous thrombosis rat model

Deep venous thrombosis (DVT) is the third leading cause of death in cardiovascular disease, following heart attacks and strokes. Early diagnosis and intervention are crucial for effective DVT therapy. We aim to investigate whether endothelin-1 (ET-1) could serve as an early diagnostic marker or a potential therapeutic target in a DVT rat model. CCK8 assay, invasion assay, and flow cytometry were used to detect the proliferation, migration and apoptosis of HUVECs, respectively. Elisa assay was used to detect ET-1 and coagulation factor VII in cell supernatant and rat?s plasma. Western blot was used to detect antioxidant signaling protein. Inferior vena cava stenosis was used to construct the DVT rat model. Lentivirus mediated overexpression of ET-1 in HUVECs impaired the cell proliferation and migration, increased cell apoptosis, inhibited the antioxidant signaling pathway proteins expression (e.g., NQO1, GCLC, Nrf-2), and upregulated coagulation factor VII. Furthermore, overexpression of ET-1 further impaired antioxidant signaling pathway protein in response to H2O2 treatment. However, lentivirus mediated ET-1 knockdown and BQ123 (an ET-1 inhibitor), showed the opposite results with ET-1 overexpression. We then established a DVT rat model by inferior vena cava stenosis. The stenosis induced early expression of ET-1 and coagulation factor VII in plasma at day 1 and restore their level at day 10. BQ123 could downregulate the coagulation factor VII to ameliorate the stenosis effects. Our findings suggest that ET-1 might serve as an early diagnostic marker for DVT rat model and a potential therapeutic target for treating DVT.

Platelet integrin αIIbβ3 plays a key role in venous thrombogenesis in a mouse model

Venous thrombosis (VT) is a common vascular disease associated with reduced survival and a high recurrence rate. Previous studies have shown that the accumulation of platelets and neutrophils at sites of endothelial cell activation is a primary event in VT, but a role for platelet αIIbβ3 in the initiation of venous thrombosis has not been established. This task has been complicated by the increased bleeding linked to partial agonism of current αIIbβ3 inhibitory drugs such as tirofiban (Aggrastat ® ). Here, we show that m-tirofiban, an engineered version of tirofiban, is not a partial agonist of αIIbβ3. This is based on its cryo-EM structure in complex with human full-length αIIbβ3 and its inability to increase expression of an activation-sensitive epitope on platelet αIIbβ3. m-tirofiban abolished agonist-induced platelet aggregation ex vivo at concentrations that preserved clot retraction and markedly suppressed the accumulation of platelets, neutrophils, and fibrin on thrombin-activated endothelium in real-time using intravital microscopy in a mouse model of venous thrombogenesis. Unlike tirofiban, however, m-tirofiban did not increase bleeding at the thrombosis-inhibitory dose. These findings establish a key role for αIIbβ3 in the initiation of VT, provide a guiding principle for designing potentially safer inhibitors for other integrins, and suggest that pure antagonists of αIIbβ3 like m-tirofiban merit further consideration as potential thromboprophylaxis agents in patients at high-risk for VT and hemorrhage.

Discovery of Heparin Mimetic, Potent, and Selective Inhibitors of Human Clotting Factor XIIIa

Factor XIIIa (FXIIIa) is a cysteine transglutaminase that catalyzes the last step in the coagulation process. An anion-binding site inhibition of FXIIIa is a paradigm-shifting strategy that may offer key advantages of controlled inhibition. Such an approach is likely to lead to novel FXIIIa inhibitors that do not carry bleeding risks. We previously reported a flavonoid trimer-based allosteric inhibitor of FXIIIa with moderate potency and selectivity. To further advance this approach, we evaluated a series of 27 variably sulfonated heparin mimetics against human FXIIIa. Only 13 molecules exhibited inhibitory activity at the highest concentration tested with IC50 values of 2-286 μM. Specifically, inhibitor 16 demonstrated an IC50 value of 2.4 ± 0.5 μM in a bisubstrate, fluorescence-based trans-glutamination assay. It also demonstrated a significant selectivity over other clotting factors including thrombin, factor Xa, and factor XIa as well as other cysteine enzymes including papain and tissue transglutaminase 2. Inhibitor 16 did not affect the viability of three human cell lines at a concentration that is 5-fold its FXIIIa-IC50. The molecule had a very weak effect on the activated partial thromboplastin time of human plasma at a concentration of >700 μM, further supporting its functional selectivity. Importantly, molecule 16 inhibited FXIIIa-mediated polymerization of fibrin(ogen) in a concentration-dependent manner as shown by the gel electrophoresis experiment. Michaelis-Menten kinetics revealed that the molecule competes with the Gln-donor protein substrate, i.e., dimethylcasein, but not with the Lys-donor small substrate, i.e., dansylcadaverine. Molecular modeling studies revealed that this type of molecule likely binds to an anion-binding site comprising the basic amino acids of Lys54, Lys61, Lys73, Lys156, and Arg244 among others. Overall, our work puts forward a new anion-binding site, selective, nontoxic, sulfonated heparin mimetic FXIIIa inhibitor 16 for further development as an effective and safer anticoagulant.

Exploration of effective biomarkers for venous thrombosis embolism in Behçet's disease based on comprehensive bioinformatics analysis

Behçet's disease (BD) is a multifaceted autoimmune disorder affecting multiple organ systems. Vascular complications, such as venous thromboembolism (VTE), are highly prevalent, affecting around 50% of individuals diagnosed with BD. This study aimed to identify potential biomarkers for VTE in BD patients. Three microarray datasets (GSE209567, GSE48000, GSE19151) were retrieved for analysis. Differentially expressed genes (DEGs) associated with VTE in BD were identified using the Limma package and weighted gene co-expression network analysis (WGCNA). Subsequently, potential diagnostic genes were explored through protein-protein interaction (PPI) network analysis and machine learning algorithms. A receiver operating characteristic (ROC) curve and a nomogram were constructed to evaluate the diagnostic performance for VTE in BD patients. Furthermore, immune cell infiltration analyses and single-sample gene set enrichment analysis (ssGSEA) were performed to investigate potential underlying mechanisms. Finally, the efficacy of listed drugs was assessed based on the identified signature genes. The limma package and WGCNA identified 117 DEGs related to VTE in BD. A PPI network analysis then selected 23 candidate hub genes. Four DEGs (E2F1, GATA3, HDAC5, and MSH2) were identified by intersecting gene sets from three machine learning algorithms. ROC analysis and nomogram construction demonstrated high diagnostic accuracy for these four genes (AUC: 0.816, 95% CI: 0.723-0.909). Immune cell infiltration analysis revealed a positive correlation between dysregulated immune cells and the four hub genes. ssGSEA provided insights into potential mechanisms underlying VTE development and progression in BD patients. Additionally, therapeutic agent screening identified potential drugs targeting the four hub genes. This study employed a systematic approach to identify four potential hub genes (E2F1, GATA3, HDAC5, and MSH2) and construct a nomogram for VTE diagnosis in BD. Immune cell infiltration analysis revealed dysregulation, suggesting potential macrophage involvement in VTE development. ssGSEA provided insights into potential mechanisms underlying BD-induced VTE, and potential therapeutic agents were identified.

Serum albumin, genetic susceptibility, and risk of venous thromboembolism

Background

Previous research on the association between serum albumin (ALB) and venous thromboembolism (VTE) has produced inconclusive results. The polygenic risk score is constructed from a set of independent risk variants associated with a disorder, enabling the identification of a larger fraction of the population at comparable or greater disease risk. It is still unknown whether ALB and genetic factors jointly contribute to the incidence of VTE.

Objectives

The present study aimed to explore ALB, genetic susceptibility, and the risk of VTE.

Methods

The present investigation was an analysis of prospectively collected data from UK Biobank, a population-based, longitudinal cohort. Cox proportional models were used to calculate hazard ratios and 95% CIs for VTE. The Kaplan-Meier curve was utilized to visualize the cumulative risk of VTE according to different serum ALB levels, and the restricted cubic spline model was leveraged to explore the exposure-response relationship among ALB levels and VTE risk.

Results

During median follow-up of 13.5 years, 11,502 cases with VTE were diagnosed among 417,113 participants in the UK Biobank. The lower ALB levels were associated with a higher risk for VTE. Individuals with both a high genetic risk and lowest ALB level had the highest risk of VTE (hazard ratio, 3.89; 95% CI, 3.41-4.43), compared with those with low genetic risk and highest ALB level. The positive joint effects of low ALB and polygenic risk score increased the risk of VTE in individuals with high genetic risk. This study excluded non-European patients and primarily focused on the European population, which may limit the generalizability of the findings.

Conclusion

Low serum ALB levels were linked to an increased risk of VTE, which was in accordance with a linear dose-response relationship. There was a positive additive effect of ALB and genetic susceptibility on the risk of VTE. ALB could serve as a biomarker for predicting the risk of VTE.

Contribution of FOS in neutrophils to venous thromboembolism via miR-144 based on bioinformatic prediction and validation

The Finkel-Biskis-Jinkins Osteosarcoma (c-Fos; encoded by FOS) plays an important role in several cardiovascular diseases, including atherosclerosis and stroke. However, the relationship between FOS and venous thromboembolism (VTE) remains unknown. We identified differentially expressed genes in Gene Expression Omnibus dataset, GSE48000, comprising VTE patients and healthy individuals, and analysed them using CIBERSORT and weighted co-expression network analysis (WGCNA). FOS and CD46 expressions were significantly downregulated (FOS p = 2.26E-05, CD64 p = 8.83E-05) and strongly linked to neutrophil activity in VTE. We used GSE19151 and performed PCR to confirm that FOS and CD46 had diagnostic potential for VTE; however, only FOS showed differential expression by PCR and ELISA in whole blood samples. Moreover, we found that hsa-miR-144 which regulates FOS expression was significantly upregulated in VTE. Furthermore, FOS expression was significantly downregulated in neutrophils of VTE patients (p = 0.03). RNA sequencing performed on whole blood samples of VTE patients showed that FOS exerted its effects in VTE via the leptin-mediated adipokine signalling pathway. Our results suggest that FOS and related genes or proteins can outperform traditional clinical markers and may be used as diagnostic biomarkers for VTE.

SGLT2 inhibition, venous thrombolism, and death due to cardiac causes: a mediation Mendelian randomization study

Objective

To investigate the causal role of venous thrombolism mediating sodium-glucose cotransporter 2 (SGLT2) inhibition in death due to cardiac causes using Mendelian randomization (MR).

Methods

A two-sample two-step MR was used to determine (1) the causal effects of SGLT2 inhibition on death due to cardiac causes; (2) the causal effects of venous thrombolism on death due to cardiac causes; and (3) the mediation effects of venous thrombolism. Genetic proxies for SGLT2 inhibition were identified as variants in the SLC5A2 gene that were associated with both levels of gene expression and hemoglobin A1c. Additionally, employing MR to investigate the causal association between SGLT2 inhibition and cardiac arrest as well as coronary heart disease (CHD).

Results

SGLT2 inhibition was associated with a lower risk of death due to cardiac causes (odds ratio [OR] = 0.983, [95% CI = 0.972, 0.993], P = 0.0016). Venous thrombolism was associated with death due to cardiac causes ([OR] = 1.031, [95% CI = 1.005, 1.057], P = 0.0199). Mediation analysis showed evidence of indirect effect of SGLT2 inhibition on death due to cardiac causes through venous thrombolism [β = -0.0015, (95% CI = -0.0032 -0.0002), P = 0.042], with a mediated proportion of 8.9% (95% CI = 1.2%, 18.7%) of the total. Furthermore, SGLT2 inhibition was linked to a lower risk of cardiac arrest ([OR] = 0.097, [95% CI = 0.013, 0.742], P = 0.025). SGLT2 inhibition was linked to a lower risk of CHD ([OR] = 0.957, [95% CI = 0.932, 0.982], P = 0.0009).

Conclusions

Our study identified the causal roles of SGLT2 inhibition in venous thrombolism. SGLT2 inhibition may influence death due to cardiac causes through venous thrombolism. Additionally, SGLT2 inhibition was associated with reduced risk of cardiac arrest and CHD.

Therapeutic effects and molecular mechanisms of natural products in thrombosis

Thrombotic disorders, such as myocardial infarction and stroke, are the leading cause of death in the global population and have become a health problem worldwide. Drug therapy is one of the main antithrombotic strategies, but antithrombotic drugs are not completely safe, especially the risk of bleeding at therapeutic doses. Recently, natural products have received widespread interest due to their significant efficacy and high safety, and an increasing number of studies have demonstrated their antithrombotic activity. In this review, articles from databases, such as Web of Science, PubMed, and China National Knowledge Infrastructure, were filtered and the relevant information was extracted according to predefined criteria. As a result, more than 100 natural products with significant antithrombotic activity were identified, including flavonoids, phenylpropanoids, quinones, terpenoids, steroids, and alkaloids. These compounds exert antithrombotic effects by inhibiting platelet activation, suppressing the coagulation cascade, and promoting fibrinolysis. In addition, several natural products also inhibit thrombosis by regulating miRNA expression, anti-inflammatory, and other pathways. This review systematically summarizes the natural products with antithrombotic activity, including their therapeutic effects, mechanisms, and clinical applications, aiming to provide a reference for the development of new antithrombotic drugs.

Venous Thromboembolism Prophylaxis in Low Body Weight Critically Ill Patients

OBJECTIVE

To compare bleeding and thromboembolic events in low body weight patients receiving reduced-dose venous thromboembolism (VTE) prophylaxis versus standard-dose VTE prophylaxis.

DESIGN

Multicenter, retrospective, cohort study.

SETTING

Five Ascension Health Hospitals.

PATIENTS

Adult, critically ill, low body weight (≤50 kg) patients who received either reduced-dose VTE prophylaxis (n = 140) or standard-dose VTE prophylaxis (n = 279) for at least 48 h.

INTERVENTION

Reduced-dose prophylaxis (enoxaparin 30 mg daily or heparin 5000 units every 12 h subcutaneously) or standard-dose prophylaxis (enoxaparin 40 mg daily, enoxaparin 30 mg every 12 h, or heparin 5000 units every 8 h subcutaneously).

MEASUREMENTS AND MAIN RESULTS

A total of 419 patients were included with a mean weight of 45.1 ± 4.2 kg in the standard-dose group and 44.0 ± 5.1 kg in the reduced-dose prophylaxis group (P = .02). The primary endpoint, composite bleeding, was significantly lower in patients receiving reduced-dose prophylaxis (5% vs 12.5%, P = .02). After adjusting for confounding factors, results remained consistent demonstrating reduced composite bleeding with reduced-dose prophylaxis (odds ratio: 0.36, 95% confidence interval: 0.14-0.96). Major bleeding events occurred in 3.6% of reduced-dose patients compared with 8.6% in standard-dose patients (P = .056). Clinically relevant nonmajor bleeding (5.4% vs 2.9%, P = .24) and VTE (2.2% vs 0%, P = .08) events were similar between groups.

CONCLUSIONS

A reduced-dose VTE prophylaxis strategy in low body weight, critically ill patients was associated with a lower risk of composite bleeding and similar rate of thromboembolism.

Circulating Cytokines and Venous Thromboembolism: A Bidirectional Two-Sample Mendelian Randomization Study

BACKGROUND

 Epidemiological evidence has linked circulating cytokines to venous thromboembolism (VTE). However, it remains uncertain whether these associations are causal due to confounding factors or reverse causality. We aim to explore the causality between circulating cytokines and VTE, encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

 In the current bidirectional Mendelian randomization (MR) study, instrumental variables of 41 circulating cytokines were obtained from the genome-wide association study meta-analyses (8,293 individuals). Summary statistics for the association of VTE (17,048 cases and 325,451 controls), DVT (8,077 cases and 295,014 controls), and PE (8,170 cases and 333,487 controls) were extracted from the FinnGen Study. A multivariable MR study was conducted to adjust for potential confounders. The inverse-variance weighted method was employed as the main analysis, and comprehensive sensitivity analyses were conducted in the supplementary analyses.

RESULTS

 The MR analysis indicated stromal cell-derived factor-1α was suggestively associated with a reduced risk of VTE (odds ratio [OR]: 0.90; 95% confidence interval [CI]: 0.81-0.99; p = 0.033) and DVT (OR: 0.85; 95% CI: 0.75-0.97; p = 0.015). In addition, suggestive association of granulocyte colony-stimulating factor with PE (OR: 1.20; 95% CI: 1.06-1.37; p = 0.005) was observed. Multivariable MR analysis showed that the effect of cytokines on VTE was partly mediated through hemoglobin A1c and systolic blood pressure. Reverse MR analysis revealed that VTE was linked to decreased levels of several cytokines.

CONCLUSION

 We provide suggestive genetic evidence supporting the bidirectional causal effect between circulating cytokines and VTE, highlighting the importance of targeting circulating cytokines to reduce the incidence of VTE.

From Hematopoietic Stem Cells to Platelets: Unifying Differentiation Pathways Identified by Lineage Tracing Mouse Models

Platelets are the terminal progeny of megakaryocytes, primarily produced in the bone marrow, and play critical roles in blood homeostasis, clotting, and wound healing. Traditionally, megakaryocytes and platelets are thought to arise from multipotent hematopoietic stem cells (HSCs) via multiple discrete progenitor populations with successive, lineage-restricting differentiation steps. However, this view has recently been challenged by studies suggesting that (1) some HSC clones are biased and/or restricted to the platelet lineage, (2) not all platelet generation follows the "canonical" megakaryocytic differentiation path of hematopoiesis, and (3) platelet output is the default program of steady-state hematopoiesis. Here, we specifically investigate the evidence that in vivo lineage tracing studies provide for the route(s) of platelet generation and investigate the involvement of various intermediate progenitor cell populations. We further identify the challenges that need to be overcome that are required to determine the presence, role, and kinetics of these possible alternate pathways.

System-Wide Thromboprophylaxis Interventions for Hospitalized Patients at Risk of Venous Thromboembolism: Focus on Cross-Platform Clinical Decision Support

Thromboprophylaxis of hospitalized patients at risk of venous thromboembolism (VTE) presents challenges owing to patient heterogeneity and lack of adoption of evidence-based methods. Intuitive practices for thromboprophylaxis have resulted in many patients being inappropriately prophylaxed. We conducted a narrative review summarizing system-wide thromboprophylaxis interventions in hospitalized patients. Multiple interventions for thromboprophylaxis have been tested, including multifaceted approaches such as national VTE prevention programs with audits, pre-printed order entry, passive alerts (either human or electronic), and more recently, the use of active clinical decision support (CDS) tools incorporated into electronic health records (EHRs). Multifaceted health-system and order entry interventions have shown mixed results in their ability to increase appropriate thromboprophylaxis and reduce VTE unless mandated through a national VTE prevention program, though the latter approach is potentially costly and effort- and time-dependent. Studies utilizing passive human or electronic alerts have also shown mixed results in increasing appropriate thromboprophylaxis and reducing VTE. Recently, a universal cloud-based and EHR-agnostic CDS VTE tool incorporating a validated VTE risk score revealed high adoption and effectiveness in increasing appropriate thromboprophylaxis and reducing major thromboembolism. Active CDS tools hold promise in improving appropriate thromboprophylaxis, especially with further refinement and widespread implementation within various EHRs and clinical workflows.

Angiogenesis in Chronic Thromboembolic Pulmonary Hypertension: A Janus-Faced Player?

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare form of pulmonary hypertension characterized by the presence of organized thrombi that obstruct pulmonary arteries, ultimately leading to right heart failure and death. Among others, impaired angiogenesis and inflammatory thrombosis have been shown to contribute to the progression of CTEPH. In this review, we summarize the 2-faced nature of angiogenesis in both thrombus formation and resolution in the context of CTEPH and highlight the dual role of angiogenesis and neovascularization in resolving venous thrombi. Furthermore, we discuss relevant in vitro and in vivo models that support the benefits or drawbacks of angiogenesis in CTEPH progression. We discuss the key pathways involved in modulating angiogenesis, particularly the underexplored role of TGFβ (transforming growth factor-beta) signaling in driving fibrosis as an integral element of CTEPH pathogenesis. We finally explore innovative treatment strategies that target angiogenic pathways. These strategies have the potential to pioneer preventive, inventive, or alternative therapeutic options for patients with CTEPH who may not qualify for surgical interventions. Moreover, they could be used synergistically with established treatments such as pulmonary endarterectomy or balloon pulmonary angioplasty. In summary, this review emphasizes the crucial role of angiogenesis in the development of in fibrothrombotic tissue, a major pathological characteristic of CTEPH.

Genetic associations of protein-coding variants in venous thromboembolism

Previous genetic studies of venous thromboembolism (VTE) have been largely limited to common variants, leaving the genetic determinants relatively incomplete. We performed an exome-wide association study of VTE among 14,723 cases and 334,315 controls. Fourteen known and four novel genes (SRSF6, PHPT1, CGN, and MAP3K2) were identified through protein-coding variants, with broad replication in the FinnGen cohort. Most genes we discovered exhibited the potential to predict future VTE events in longitudinal analysis. Notably, we provide evidence for the additive contribution of rare coding variants to known genome-wide polygenic risk in shaping VTE risk. The identified genes were enriched in pathways affecting coagulation and platelet activation, along with liver-specific expression. The pleiotropic effects of these genes indicated the potential involvement of coagulation factors, blood cell traits, liver function, and immunometabolic processes in VTE pathogenesis. In conclusion, our study unveils the valuable contribution of protein-coding variants in VTE etiology and sheds new light on its risk stratification.

In situ formed depot of elastin-like polypeptide-hirudin fusion protein for long-acting antithrombotic therapy

Thrombosis, induced by abnormal coagulation or fibrinolytic systems, is the most common pathology associated with many life-threatening cardio-cerebrovascular diseases. However, first-line anticoagulant drugs suffer from rapid drug elimination and risk of hemorrhagic complications. Here, we developed an in situ formed depot of elastin-like polypeptide (ELP)-hirudin fusion protein with a prodrug-like feature for long-term antithrombotic therapy. Highly secretory expression of the fusion protein was achieved with the assistance of the Ffu312 tag. Integration of hirudin, ELP, and responsive moiety can customize fusion proteins with properties of adjustable in vivo retention and controllable recovery of drug bioactivity. After subcutaneous injection, the fusion protein can form a reservoir through temperature-induced coacervation of ELP and slowly diffuse into the blood circulation. The biological activity of hirudin is shielded due to the N-terminal modification, while the activated key proteases upon thrombus occurrence trigger the cleavage of fusion protein together with the release of hirudin, which has antithrombotic activity to counteract thrombosis. We substantiated that the optimized fusion protein produced long-term antithrombotic effects without the risk of bleeding in multiple animal thrombosis models.

Comprehensive Analysis of the Role of Fibrinogen and Thrombin in Clot Formation and Structure for Plasma and Purified Fibrinogen

Altered properties of fibrin clots have been associated with bleeding and thrombotic disorders, including hemophilia or trauma and heart attack or stroke. Clotting factors, such as thrombin and tissue factor, or blood plasma proteins, such as fibrinogen, play critical roles in fibrin network polymerization. The concentrations and combinations of these proteins affect the structure and stability of clots, which can lead to downstream complications. The present work includes clots made from plasma and purified fibrinogen and shows how varying fibrinogen and activation factor concentrations affect the fibrin properties under both conditions. We used a combination of scanning electron microscopy, confocal microscopy, and turbidimetry to analyze clot/fiber structure and polymerization. We quantified the structural and polymerization features and found similar trends with increasing/decreasing fibrinogen and thrombin concentrations for both purified fibrinogen and plasma clots. Using our compiled results, we were able to generate multiple linear regressions that predict structural and polymerization features using various fibrinogen and clotting agent concentrations. This study provides an analysis of structural and polymerization features of clots made with purified fibrinogen or plasma at various fibrinogen and clotting agent concentrations. Our results could be utilized to aid in interpreting results, designing future experiments, or developing relevant mathematical models.

CD14 Blockade Does Not Improve Outcomes of Deep Vein Thrombosis Following Inferior Vena Cava Stenosis in Mice

Background

Neutrophil-mediated persistent inflammation and neutrophil extracellular trap formation (NETosis) promote deep vein thrombosis (DVT). CD14, a co-receptor for toll-like receptor 4 (TLR4), is actively synthesized by neutrophils, and the CD14/TLR4 signaling pathway has been implicated in proinflammatory cytokine overproduction and several aspects of thromboinflammation. The role of CD14 in the pathogenesis of DVT remains unclear.

Objective

To determine whether CD14 blockade improves DVT outcomes.

Methods

Bulk RNA sequencing and proteomic analyses were performed using isolated neutrophils following inferior vena cava (IVC) stenosis in mice. DVT outcomes (IVC thrombus weight and length, thrombosis incidence, neutrophil recruitment, and NETosis) were evaluated following IVC stenosis in mice treated with a specific anti-CD14 antibody, 4C1, or control antibody.

Results

Mice with IVC stenosis exhibited increased plasma levels of granulocyte colony-stimulating factor (G-CSF) along with a higher neutrophil-to-lymphocyte ratio and increased plasma levels of cell-free DNA, elastase, and myeloperoxidase. Quantitative measurement of total neutrophil mRNA and protein expression revealed distinct profiles in mice with IVC stenosis compared to mice with sham surgery. Neutrophils of mice with IVC stenosis exhibited increased inflammatory transcriptional and proteomic responses, along with increased expression of CD14. Treatment with a specific anti-CD14 antibody, 4C1, did not result in any significant changes in the IVC thrombus weight, thrombosis incidence, or neutrophil recruitment to the thrombus.

Conclusion

The results of the current study are important for understanding the role of CD14 in the regulation of DVT and suggest that CD14 lacks an essential role in the pathogenesis of DVT following IVC stenosis.

Risk factors for incident venous thromboembolism in patients with renal tumor and inferior vena cava tumor thrombus: a retrospective case-control study

BACKGROUND

Venous thromboembolism (VTE) is a principal cause of mortality and adverse oncologic outcomes in patients with renal tumor and inferior vena cava tumor thrombus (RT-IVCTT). However, the preoperative thrombotic risk factors in these patients remain not fully characterized.

OBJECTIVES

To identify preoperative thrombotic risk factors in patients with RT-IVCTT.

PATIENTS/METHODS

Two hundred fifty-seven consecutive postsurgical patients with RT-IVCTT aged 18-86 years were enrolled between January 2008 and September 2022. Clinicopathological variables were retrospectively reviewed. A multivariate logistic regression model was performed. Preoperative hemoglobin, neutrophils, and serum albumin levels were analyzed as both continuous and categorical variables.

RESULTS

VTE was identified in 63 patients (24.5%). On both continuously and categorically coded variables, advanced IVC thrombus (OR 3.2, 95% CI: 1.4-7.0; OR 2.7, 95% CI: 1.2-6.1), renal sinus fat invasion (OR 3.4, 95% CI: 1.6-7.0; OR 3.7, 95% CI: 1.8-7.7), IVC wall invasion (OR 3.6, 95% CI: 1.6-7.9; OR 4.3, 95% CI: 1.9-10.0), IVC blockage status of greater than 75% (OR 5.2, 95% CI: 1.7-15.8; OR 6.1, 95% CI: 1.9-19.7), and higher neutrophils (OR 1.3, 95% CI: 1.0-1.7; OR 2.4, 95% CI: 1.1-5.4) were significantly associated with increased VTE risk in patients with RT-IVCTT. Except hemoglobin, categorically coded serum albumin (OR 0.36, 95% CI: 0.17-0.75) was validated as an independent risk factor for VTE.

CONCLUSIONS

This study provided an insight of risk factors contributing to preoperative VTE in patients with RT-IVCTT, which may be beneficial for optimizing strategies to manage VTE in clinical practice.

Nomogram for predicting postoperative deep vein thrombosis in patients with spinal fractures caused by high-energy injuries

OBJECTIVE

Deep venous thrombosis (DVT) is a common complication in patients with spinal fractures caused by high-energy injuries. Early identification of patients at high risk of postoperative DVT is essential for the prevention of thrombosis. This study aimed to develop and validate a prediction model based on a nomogram to predict DVT in patients with spinal fractures caused by high-energy injuries.

METHODS

Clinical data were collected from 936 patients admitted to our hospital between January 2016 and December 2021 with spinal fractures caused by high-energy injuries. Multivariate logistic regression analysis was used to identify the risk factors for postoperative DVT and to develop a nomogram. The predictive performance of the nomogram was evaluated by the receiver operating characteristic (ROC) curve and calibration curve.

RESULTS

The incidence of preoperative DVT was 15.38% (144/936). The postoperative incidence of DVT was 20.5% (192/936). The multivariate analysis revealed that age, operation time, blood transfusion, duration of bed rest, American Spinal Injury Association (ASIA) score and D-dimer were risk factors for postoperative DVT. The area under the ROC curve of the nomogram was 0.835 and the calibration curve showed good calibration.

CONCLUSIONS

The nomogram showed a good ability to predict postoperative DVT in patients with spinal fractures caused by high-energy injuries, which may benefit pre- and postoperative DVT prophylaxis strategy development.

Platelet Microvesicles, Inflammation, and Coagulation Markers: A Pilot Study

BACKGROUND

Platelet "Microvesicles" (MVs) are studied for their role in blood coagulation and inflammation. The study aimed to establish if MVs are related to age, plasma levels of inflammation, coagulation, and fibrinolysis markers in healthy individuals.

METHODS

We prospectively enrolled volunteers aged over 18 years. MVs, plasma levels of C-reactive protein (CRP), Interleukin 6 (IL-6), Interleukin 10 (IL-10), Interleukin 17 (IL-17), and transforming growth factor β (TGF-β), fibrinogen, plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (VWF), homocysteine, factor VII (FVII), thrombin activatable fibrinolysis inhibitor (TAFI), and Protein S were tested.

RESULTS

A total of 246 individuals (median age 65 years ("IQR"54-72)) were evaluated. Both univariate analysis and logistic regression models showed that MVs positively correlate with age, CRP, IL-6, IL-10, IL-17, TGF-β, fibrinogen, PAI-1, VWF, FVII, and homocysteine, while inversely correlating with TAFI and Protein S. The ROC curve analysis performed to identify a cut off for MV values (700 kMP) showed a good accuracy with over-range cytokines fibrinolysis factor and coagulation markers.

CONCLUSIONS

To the best of our knowledge, this study is the first to correlate MVs with an entire panel of cardiovascular risk factors in healthy individuals. A future possible role of MVs in screening exams is suggested.

Life's Essential 8 is associated with atherosclerotic cardiovascular disease but not venous thromboembolism in men: a prospective cohort study

Background: Atherosclerotic cardiovascular disease (ASCVD) shares several risk factors with venous thromboembolism (VTE). The American Heart Association's Life's Simple 7 (LS7), which included seven health and behavioural factors for CVD prevention, has recently been upgraded to Life's Essential 8 (LE8) score. We aimed to examine the prospective association between LE8 and the risks of ASCVD and VTE in Finland.Methods: We utilized data based on 1899 men aged 42-61 years in the Kuopio Ischaemic Heart Disease (KIHD) prospective study. The LE8 score was generated from baselines measures of four health behaviours (physical activity, diet, nicotine exposure and sleep health) and four health factors (BMI, blood lipids, blood glucose and blood pressure). Each factor was scored from 0 to 100 and summed into a composite score. Participants were classified into quartiles (Q) based on the total LE8 score - Q1, ≤ 420; Q2, >420 to 485; Q3, >485 to 550; Q4, >550. Multivariable Cox regression models were utilized to determine the hazard ratios (HRs) along with the 95% confidence intervals (CI) for ASCVD and VTE.Results: After median follow-up durations of 24 and 25 years, 889 ASCVD and 127 VTE events were recorded, respectively. The risk of ASCVD was found to be 58% lower in men belonging to the highest LE8 quartile compared to those in the lowest quartile (HR:0.42; 95%CI: 0.34-0.51). There was no significant evidence of an association between LE8 and VTE risk (Q4 vs Q1, HR:1.02; 95%CI: 0.60-1.74).Conclusion: The risk of ASCVD was significantly lower in middle-aged and older Finnish men who had a high LE8 score, but there was no significant association with VTE. Further large-scale prospective studies conducted in women and other population groups are necessary to confirm these findings.

Complications in Osteonecrosis Patients Following Total Knee Arthroplasty: A Propensity-Matched Cohort Study

BACKGROUND

Several studies have demonstrated high complication rates in osteonecrosis (ON) patients undergoing total hip arthroplasty. However, there is a paucity of literature regarding outcomes of total knee arthroplasty (TKA) in ON patients. Our study aimed to assess preoperative risk factors associated with the development of ON and determine the incidence of postoperative complications up to one year following TKA.

METHODS

A retrospective cohort study was conducted using a large national database. Patients who had a primary TKA and ON were isolated using Current Procedural Terminology code 27447 and ICD-10-CM code M87, respectively. A total of 185,045 patients were identified, including 181,151 patients who had a TKA and 3,894 patients who had a TKA and ON. After propensity matching, both groups each contained 3,758 patients. Intercohort comparisons of primary and secondary outcomes after propensity score matching were made using the odds ratio. A P value of < .01 was determined to be significant.

RESULTS

The ON patients were found to have an increased risk for prosthetic joint infection, urinary tract infection, deep vein thrombosis, pulmonary embolism, wound dehiscence pneumonia, and the development of heterotopic ossification at different time points. Osteonecrosis patients had an increased risk of revision at the 1-year time point (odds ratio = 2.068, P < .0001).

CONCLUSION

The ON patients had a higher risk of systemic and joint complications than non-ON patients. These complications suggest a more complicated management course for patients who have ON prior to and after TKA.

Periprostatic adipose tissue thromboinflammation triggers prostatic neoplasia in early metabolic impairment: Interruption by rivaroxaban

AIMS

Prostate cancer is among the highest incidence malignancies in men with a prevalence rate increasing in parallel to the rising global trends in metabolic disorders. Whereas a sizeable body of evidence links metabolic impairment to negative prognosis of prostate cancer, the molecular mechanism underlying this connection has not been thoroughly examined. Our previous work showed that localized adipose tissue inflammation occurring in select adipose depots in early metabolic derangement instigated significant molecular, structural, and functional alterations in neighboring tissues underlying the complications observed at this stage. In this context, the periprostatic adipose tissue (PPAT) constitutes an understudied microenvironment with potential influence on the prostatic milieu.

MAIN METHODS AND RESULTS

We show that PPAT inflammation occurs in early prediabetes with signs of increased thrombogenic activity including enhanced expression and function of Factor X. This was mirrored by early neoplastic alterations in the prostate with fibrosis, increased epithelial thickness with marked luminal cellular proliferation and enhanced formation of intraepithelial neoplasia. Significantly, interruption of the procoagulant state in PPAT by a 10-day anticoagulant rivaroxaban treatment not only mitigated PPAT inflammation, but also reduced signs of prostatic neoplastic changes. Moreover, rivaroxaban decreased the murine PLum-AD epithelial prostatic cell viability, proliferation, migration, and colony forming capacity, while increasing oxidative stress. A protease-activated receptor-2 agonist reversed some of these effects.

SIGNIFICANCE

We provide some evidence of a molecular framework for the crosstalk between PPAT and prostatic tissue leading to early neoplastic changes in metabolic impairment mediated by upregulation of PPAT thromboinflammation.

Effective Prevention of Arterial Thrombosis with Albumin-Thrombin Inhibitor Conjugates

Thromboprophylaxis is indicated in patients at an elevated risk of developing thrombotic disorders, typically using direct oral anticoagulants or low-molecular-weight heparins. We postulated that transient thromboprophylaxis (days-weeks) could be provided by a single dose of an anticoagulant engineered for prolonged pharmacokinetics. In the present work, d-phenylalanyl-l-prolyl-l-arginine chloromethyl ketone (PPACK) was used as a model anticoagulant to test the hypothesis that conjugation of thrombin inhibitors to the surface of albumin would provide durable protection against thrombotic insults. Covalent conjugates were formed between albumin and PPACK using click chemistry, and they were tested in vitro using a thrombin activity assay and a clot formation assay. Thromboprophylactic efficacy was tested in mouse models of arterial thrombosis, both chemically induced (FeCl3) and following ischemia-reperfusion (transient middle cerebral artery occlusion; tMCAO). Albumin-PPACK conjugates were shown to have nanomolar potency in both in vitro assays, and following intravenous injection had prolonged circulation. Conjugates did not impact hemostasis (tail clipping) or systemic coagulation parameters in normal mice. Intravenous injection of conjugates prior to FeCl3-induced thrombosis provided significant protection against occlusion of the middle cerebral and common carotid arteries, and injection immediately following ischemia-reperfusion reduced stroke volume measured 3 days after injury by ∼40% in the tMCAO model. The data presented here provide support for the use of albumin-linked anticoagulants as an injectable, long-circulating, safe thromboprophylactic agent. In particular, albumin-PPACK provides significant protection against thrombosis induced by multiple mechanisms, without adversely affecting hemostasis.

Traumatic muscle injury

Traumatic muscle injury represents a collection of skeletal muscle pathologies caused by trauma to the muscle tissue and is defined as damage to the muscle tissue that can result in a functional deficit. Traumatic muscle injury can affect people across the lifespan and can result from high stresses and strains to skeletal muscle tissue, often due to muscle activation while the muscle is lengthening, resulting in indirect and non-contact muscle injuries (strains or ruptures), or from external impact, resulting in direct muscle injuries (contusion or laceration). At a microscopic level, muscle fibres can repair focal damage but must be completely regenerated after full myofibre necrosis. The diagnosis of muscle injury is based on patient history and physical examination. Imaging may be indicated to eliminate differential diagnoses. The management of muscle injury has changed within the past 5 years from initial rest, immobilization and (over)protection to early activation and progressive loading using an active approach. One challenge of muscle injury management is that numerous medical treatment options, such as medications and injections, are often used or proposed to try to accelerate muscle recovery despite very limited efficacy evidence. Another challenge is the prevention of muscle injury owing to the multifactorial and complex nature of this injury.

Molecular Dynamics Simulation Study of the Selective Inhibition of Coagulation Factor IXa over Factor Xa

Thromboembolic disorders, arising from abnormal coagulation, pose a significant risk to human life in the modern world. The FDA has recently approved several anticoagulant drugs targeting factor Xa (FXa) to manage these disorders. However, these drugs have potential side effects, leading to bleeding complications in patients. To mitigate these risks, coagulation factor IXa (FIXa) has emerged as a promising target due to its selective regulation of the intrinsic pathway. Due to the high structural and functional similarities of these coagulation factors and their inhibitor binding modes, designing a selective inhibitor specifically targeting FIXa remains a challenging task. The dynamic behavior of protein-ligand interactions and their impact on selectivity were analyzed using molecular dynamics simulation, considering the availability of potent and selective compounds for both coagulation factors and the co-crystal structures of protein-ligand complexes. Throughout the simulations, we examined ligand movements in the binding site, as well as the contact frequencies and interaction fingerprints, to gain insights into selectivity. Interaction fingerprint (IFP) analysis clearly highlights the crucial role of strong H-bond formation between the ligand and D189 and A190 in the S1 subsite for FIXa selectivity, consistent with our previous study. This dynamic analysis also reveals additional FIXa-specific interactions. Additionally, the absence of polar interactions contributes to the selectivity for FXa, as observed from the dynamic profile of interactions. A contact frequency analysis of the protein-ligand complexes provides further confirmation of the selectivity criteria for FIXa and FXa, as well as criteria for binding and activity. Moreover, a ligand movement analysis reveals key interaction dynamics that highlight the tighter binding of selective ligands to the proteins compared to non-selective and inactive ligands.

Use of patient-reported outcome measures in patients with venous thromboembolism: communication from the ISTH SSC Subcommittee on Predictive and Diagnostic Variables in Thrombotic Disease

Patient-reported outcome measures (PROMs) are patient-completed instruments that capture patient-perceived health status and well-being. PROMs measure disease impact and outcomes of care as reported by those who experience the disease. After pulmonary embolism or deep vein thrombosis, patients may face a broad spectrum of complications and long-term sequelae beyond the usual quality-of-care indicators of recurrent venous thromboembolism (VTE), bleeding complications, and survival. The full impact of VTE on individual patients can only be captured by assessing all relevant health outcomes from the patient's perspective in addition to the traditionally recognized complications. Defining and measuring all important outcomes will help facilitate treatment tailored to the needs and preferences of patients and may improve health outcomes. The International Society on Thrombosis and Haemostasis Scientific and Standardization Committee Subcommittee on Predictive and Diagnostic Variables in Thrombotic Disease endorsed the International Consortium for Health Outcomes Measurement (ICHOM) VTE project on development of a standardized set of patient-centered outcome measures for patients with VTE. In this communication, the course and result of the project are summarized, and based on these findings, we propose recommendations for the use of PROMs during clinical follow-up of patients with VTE. We describe challenges to implementation of PROMs and explore barriers and enablers.

Protective Role of Endothelial SIRT1 in Deep Vein Thrombosis and Hypoxia-induced Endothelial Dysfunction Mediated by NF-κB Deacetylation

Venous hypoxia is considered as the major pathogenetic mechanism linking blood flow stagnancy with deep vein thrombosis (DVT). Our previous study showed that activating SIRT1 may attenuate inferior vena cava (IVC) stenosis-induced DVT in rats. This study was aimed to investigate the role of endothelial SIRT1 in DVT and hypoxia-induced endothelial dysfunction as well as the underlying mechanism. Protein profiling of IVCs and blood plasma of DVT rats induced by IVC stenosis was analysed by 4D Label free proteomics analysis. To verify the independent role of SIRT1 in DVT and oxygen-glucose deprivation (OGD)-induced endothelial dysfunction, SIRT1 specific activator SRT1720 and SIRT1 knockdown in both local IVCs and endothelial cells were employed. Moreover, the role of the NF-κB were investigated using NF-κB inhibitor caffeic acid phenethyl ester (CAPE). SRT1720 significantly inhibited thrombus burden, leukocytes infiltration, protein expressions of cell adhesion molecules and chemokines, as well as acetylation level of NF-κB/p65 in wild DVT rats, while these protective effects of SRT1720 were abolished in rats with SIRT1 knockdown in local IVCs. In vitro, SRT1720 protected endothelial cells against OGD-induced dysfunction characterized with enhanced adhesion of monocytes as well as the protein expressions of cell adhesion molecules and chemokines, whereas these protective effects of SRT1720 were vanished by SIRT1 stable knockdown. Furthermore, CAPE attenuated endothelial cell dysfunction and abolished these effects of SIRT1 knockdown. Collectively, these data suggested that endothelial SIRT1 plays an independent role in ameliorating hypoxia-induced endothelial dysfunction and thrombotic inflammation in DVT, and this effect is mediated by NF-κB deacetylation.

Systemic thrombolysis with newer thrombolytics vs anticoagulation in acute intermediate risk pulmonary embolism: a systematic review and meta-analysis

BACKGROUND

Randomized controlled trials (RCTs) comparing systemic thrombolysis to anticoagulation in intermediate risk pulmonary embolism (PE) have yielded mixed results. A prior meta-analysis on this topic had included studies that used lower than standard dose of thrombolytics and included thrombolytic agents that are no longer available. Hence, interpreting the findings of that paper is not valid in contemporary practice.

OBJECTIVES

We undertook a systematic review and meta-analysis of randomized controlled trials of systemic thrombolysis with newer thrombolytic agents vs anticoagulation in intermediate risk PE.

METHODS

This systematic review and meta-analysis is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement.

RESULTS

Nine randomized controlled trials were included in the study. We did not find any difference in in-hospital mortality (RR: 0.79; 95% CI: 0.42-1.50; I2: 0) or risk of major bleeding (RR:2.08;95% CI: 0.98-4.42; I2: 23.9%) between systemic thrombolysis and anticoagulation. Systemic thrombolysis was associated with lower risks for vasopressor use (RR: 0.27; 95% CI: 0.11-0.64, I2: 0) and secondary/rescue thrombolysis (RR: 0.25; 95% CI: 0.14-0.45; I2: 0). But systemic thrombolysis was found to have an increased risk of intracranial hemorrhage (RR: 4.55; 95% CI: 1.30-15.91; I2:0). There was no difference in mechanical ventilation between the two groups (RR: 0.61; 95% CI: 0.31-1.19, I2:0).

CONCLUSION

In our meta-analysis of randomized controlled trials of systemic thrombolysis vs anticoagulation in intermediate risk PE, we did not find any difference in in-hospital mortality or overall risk of major bleeding. With systemic thrombolysis, we found lower risks for vasopressor use and need for secondary/ rescue thrombolysis and an increased risk of intracranial hemorrhage.

Inhibition of Factor XI: A New Era in the Treatment of Venous Thromboembolism in Cancer Patients?

Direct oral anticoagulants against activated factor X and thrombin were the last milestone in thrombosis treatment. Step by step, they replaced antivitamin K and heparins in most of their therapeutic indications. As effective as the previous anticoagulant, the decreased but persistent risk of bleeding while using direct oral anticoagulants has created space for new therapeutics aiming to provide the same efficacy with better safety. On this basis, drug targeting factor XI emerged as an option. In particular, cancer patients might be one of the populations that will most benefit from this technical advance. In this review, after a brief presentation of the different factor IX inhibitors, we explore the potential benefit of this new treatment for cancer patients.

Risk of Incident Venous Thromboembolism Among Patients With Bullous Pemphigoid or Pemphigus Vulgaris: A Nationwide Cohort Study With Meta-Analysis

Background Bullous pemphigoid (BP) and pemphigus vulgaris (PV) share similar pathophysiology with venous thromboembolism (VTE) involving platelet activation, immune dysregulation, and systemic inflammation. Nevertheless, their associations have not been well established. Methods and Results To examine the risk of incident VTE among patients with BP or PV, we performed a nationwide cohort study using Taiwan's National Health Insurance Research Database and enrolled 12 162 adults with BP or PV and 12 162 controls. A Cox regression model considering stabilized inverse probability weighting was used to calculate the hazard ratios (HRs) for incident VTE associated with BP or PV. To consolidate the findings, a meta-analysis that incorporated results from the present cohort study with previous literature was also conducted. Compared with controls, patients with BP or PV had an increased risk for incident VTE (HR, 1.87 [95% CI, 1.55-2.26]; P<0.001). The incidence of VTE was 6.47 and 2.20 per 1000 person-years in the BP and PV cohorts, respectively. The risk for incident VTE significantly increased among patients with BP (HR, 1.85 [95% CI, 1.52-2.24]; P<0.001) and PV (HR, 1.99 [95% CI, 1.02-3.91]; P=0.04). In the meta-analysis of 8 studies including ours, BP and PV were associated with an increased risk for incident VTE (pooled relative risk, 2.17 [95% CI, 1.82-2.62]; P<0.001). Conclusions BP and PV are associated with an increased risk for VTE. Preventive approaches and cardiovascular evaluation should be considered particularly for patients with BP or PV with concomitant risk factors such as hospitalization or immobilization.

Safety and efficacy of apixaban versus low-molecular weight heparin or vitamin-K antagonists for venous thromboembolism treatment in patients with severe renal failure: A systematic review and meta-analysis

INTRODUCTION

Chronic kidney disease is an independent risk factor for venous thromboembolism (VTE). Traditionally, Low Molecular Weight Heparin (LMWH) followed by warfarin has been the conventional therapy for VTE treatment. Direct oral anticoagulants (DOACs), including apixaban, have shown several advantages over the traditional therapy in individuals with normal kidney function. This meta-analysis aims to review the safety and efficacy of apixaban compared to warfarin or LMWH for the treatment of VTE in severe renal failure.

METHOD

We conducted literature search in PubMed, Embase, and Cochrane databases. Retrospective observational studies involving clinical effectiveness and safety outcomes of apixaban compared to warfarin in adult patients with an estimated glomerular filtration rate (eGFR) <30 mL/min/m2 or on dialysis were included.

RESULTS

Eight studies were included in the analysis. Significant reduction in VTE recurrence observed in apixaban compared to warfarin (RR, 0.65; 95 % CI, 0.43-0.98; P = 0.04; I2 = 78 %). No significant difference in all-cause mortality between apixaban and warfarin (RR, 0.99; 95 % CI, 0.91-1.07; P = 0.74; I2 = 0 %). Apixaban showed a significantly lower rate of major bleeding (RR, 0.72; 95 % CI, 0.62-0.84; P < 0.0001; I2 = 34 %) and minor bleeding events (RR, 0.42; 95 % CI, 0.21-0.86; P = 0.02; I2 = 10 %) compared to warfarin. No significant difference observed in clinically relevant non-major bleeding between apixaban and warfarin (RR, 0.81; 95 % CI, 0.65-1.00; P = 0.05; I2 = 67 %).

CONCLUSION

Apixaban was favored over warfarin for treating VTE in severe renal failure, reducing VTE recurrence and bleeding risk. No differences were observed in all-cause mortality and CRNMB events. More evidence is required due to limited RCTs and prospective studies.

Vortex-ultrasound for microbubble-mediated thrombolysis of retracted clots

Endovascular sonothrombolysis has gained significant attention due to its benefits, including direct targeting of the thrombus with sonication and reduced side effects. However, the small aperture of endovascular transducers restricts the improvement of their potential clinical efficiency due to inefficient acoustic radiation. Hence, in an earlier study, we used vortex ultrasound with an endovascular ultrasound transducer to induce shear stress and enhance the clot lysis. In this study, the vortex acoustic transduction mechanism was investigated using numerical simulations and hydrophone tests. Following this characterization, we demonstrated the performance of the vortex ultrasound transducer in thrombolysis of retracted clots in in vitro tests. The test results indicated that the maximum lysis rates were 79.0% and 32.2% with the vortex ultrasound for unretracted and retracted clots, respectively. The vortex ultrasound enhanced the efficiency of the thrombolysis by approximately 49%, both for retracted and unretracted clots, compared with the typical non-vortex ultrasound technique. Therefore, the use of endovascular vortex ultrasound holds promise as a potential clinical option for the thrombolysis of retracted clots.

Congenital thrombophilia in East-Asian venous thromboembolism population: a systematic review and meta-analysis

Background

Various inherited traits contribute to the overall risk of venous thromboembolism (VTE). In addition, the epidemiology of thrombophilia in the East-Asian VTE population remains unclear; thus, we aimed to assess the proportion of hereditary thrombophilia via a meta-analysis.

Methods

Publications from PubMed, EMBASE, web of science, and Cochrane before December 30, 2022, were searched. Studies from Japan, Korea, China, Hong Kong, Taiwan, Singapore, Thailand, Vietnam, Myanmar, and Cambodia were included. Congenital thrombophilia was described as diseases including protein C (PC) deficiency, protein S (PS) deficiency, antithrombin (AT) deficiency, factor (F)V Leiden (FVL), and prothrombin G20210A mutations. Studies were selected by 2 reviewers for methodological quality analysis. A random-effects model was used for the meta-analysis, assuming that estimated effects in the different studies are not identical.

Results

Forty-four studies involving 6453 patients from 7 counties/regions were included in the meta-analysis. The prevalence of PC, PS, and AT deficiencies were 7.1%, 8.3%, and 3.8%, respectively. Among 2924 patients from 22 studies, 5 patients were carriers of FVL mutation. Among 2196 patients from 10 studies, 2 patients were carriers of prothrombin G20210A mutation in a Thailand study.

Conclusion

The prevalence of PC, PS, and AT deficiencies was relatively high, while a much lower prevalence of FVL and prothrombin G20210A mutations were identified in East-Asian patients with VTE. Our data stress the relative higher prevalence of PC, PS, and AT deficiencies for thrombophilia in the East-Asian VTE population.

Surgery As a Trigger for Incident Venous Thromboembolism: Results from a Population-Based Case-Crossover Study

Background  Surgery is a major transient risk factor for venous thromboembolism (VTE). However, the impact of major surgery as a VTE trigger has been scarcely investigated using a case-crossover design. Aim  To investigate the role of major surgery as a trigger for incident VTE in a population-based case-crossover study while adjusting for other concomitant VTE triggers. Methods  We conducted a case-crossover study with 531 cancer-free VTE cases derived from the Tromsø Study cohort. Triggers were registered during the 90 days before a VTE event (hazard period) and in four preceding 90-day control periods. Conditional logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for VTE according to major surgery and after adjustment for other VTE triggers. Results  Surgery was registered in 85 of the 531 (16.0%) hazard periods and in 38 of the 2,124 (1.8%) control periods, yielding an OR for VTE of 11.40 (95% CI: 7.42-17.51). The OR decreased to 4.10 (95% CI: 2.40-6.94) after adjustment for immobilization and infection and was further attenuated to 3.31 (95% CI: 1.83-5.96) when additionally adjusted for trauma, blood transfusion, and central venous catheter. In a mediation analysis, 51.4% (95% CI: 35.5-79.7%) of the effect of surgery on VTE risk could be mediated through immobilization and infection. Conclusions  Major surgery was a trigger for VTE, but the association between surgery and VTE risk was in part explained by other VTE triggers often coexisting with surgery, particularly immobilization and infection.

Clinical Observation of Uninterrupted Thrombolytic Therapy via Indwelling Catheter for Lower Limb Deep Vein Thrombosis

Purpose

Observe uninterrupted thrombolytic therapy via indwelling catheter for lower limb deep vein thrombosis.

Methods

We retrospectively studied data from 32 patients with lower extremity deep vein thrombosis who received comprehensive treatment, consisting of general treatment, inferior vena cava filter implantation, interventional thrombolysis, angioplasty, stenting, and post-operative monitoring.

Results

The efficacy and safety of the comprehensive treatment were observed for a follow-up period of 6-12 months. The treatment was 100% effective; patient results indicated no serious bleeding, acute pulmonary embolism, or death after surgery.

Conclusion

The combination of intravenous and healthy side femoral vein puncture and directed thrombolysis to treat acute lower limb deep vein thrombosis is safe, effective, and minimally invasive while still achieving a good therapeutic effect.

Silica Nanoparticles Promote the Megakaryocyte Maturation and Differentiation: Potential Implications for Hematological Homeostasis

Silica nanoparticles (SiO₂ NPs) have been widely applied in diverse areas, thus causing the extensive release through multiple routes. Their toxicological effects, especially for the disturbance in hematological homeostasis, have raised public concern. Considering the detrimental role of excessive platelets in many cardiovascular diseases, the regulation of platelet formation offers a unique aspect for studying the blood compatibility of nanomaterials. In this study, the effects of SiO₂ NPs with four sizes (80, 120, 200, and 400 nm) were investigated on the maturation and differentiation of the megakaryocytes into platelets. The results showed that SiO₂ NPs promoted megakaryocyte development as manifested by the occurrence of irregular cell morphology, enlargement of cell size, increases in DNA content and DNA ploidy, and formation of spore-like protrusions. The expression of megakaryocyte-specific antigen (CD41a) was up-regulated, due to SiO₂ NP treatments. The correlation analysis of SiO₂ NP size with the above test bioindicators showed that the smaller the SiO₂ NPs were, the stronger effects they induced. Moreover, exposure to SiO₂ NPs induced the up-regulation of both GATA-1 and FLI-1, while the transcriptional expressions of aNF-E2 and fNF-E2 remained unchanged. The significant positive correlation of GATA-1 and FLI-1 with megakaryocytic maturation and differentiation suggested their crucial roles in the SiO₂ NP-promoted effect. The finding herein provided new insight into the potential health risk of SiO₂ NPs by perturbing the platelet-involved hematological homeostasis.