Journal of Thrombosis and Haemostasis最新文献

Background: Serine-threonine kinase 10 (STK10) is a member of Ste20 family of serine/threonine kinases. Our previous study showed STK10 is expressed in platelets and regulates platelet function in arterial thrombosis. Whether it plays a role in venous thrombosis remains unclear.

Objectives: In this study, we aim to investigate the role of platelet STK10 in deep vein thrombosis (DVT) by using platelet-specific STK10 knockout mice.

Methods: A DVT model was constructed via ligation of the inferior vena cava, and 24 hours later, an inferior vena cava sample was obtained for analysis of thrombi length and weight, the accumulation of platelets, neutrophils, platelet-neutrophil interaction, neutrophil extracellular traps (NET) formation, and platelet procoagulant function by immunofluorescence staining.

Results: During the development of DVT in mouse models, a significantly increased STK10 phosphorylation along with an increase of integrin-linked protein kinase phosphorylation (Ser343) was observed in the platelets. Deletion of platelet STK10 reduced the incidence and severity of DVT and inhibited platelet activation, platelet-neutrophil interaction, the recruitment and accumulation of platelets and neutrophils, and NET formation in the venous thrombin. In addition, absence of platelet STK10 inhibits NET formation induced by thrombin-stimulated platelets in vitro. Moreover, deficiency of platelet STK10 decreased platelet procoagulant activity in the peripheral blood and venous thrombi.

Conclusion: Our study shows a novel regulatory role of platelet STK10 in the development and pathogenesis of DVT, implying that targeting platelet STK10 might be a novel approach for the prevention and treatment of venous thrombosis.

Introduction: Severe haemophilia A (HA), defined by a clotting factor VIII (FVIII) level <1%, leads to a severe bleeding tendency. A pathogenic F8 variant p.His300Lysfs*41 accounted for <1% FVIII levels in a HA patient, however he exhibited a discordantly mild-to-moderate bleeding phenotype.

Methods: Multigene sequencing to detect possible genetic modifiers identified a heterozygous PROC variant (p.Trp414Arg). Plasma protein C (PC) activity and antigen were measured. Recombinant wild-type and mutant PC were produced using Expi293F™ cells with function and quantity measured by chromogenic activity assays and competitive ELISA. Protein structure was predicted with AlphaFold 3. Thrombin generation assays (TGA) in FVIII-deficient plasma with varying PC concentrations were used to assess anticoagulant activity.

Results: PC activity in the patient's plasma was 58% (clotting-based) and 53% (chromogenic), and PC antigenic concentration was 59%. Mutant PC in transfection supernatant demonstrated concordant marked reduction in PC activity (0% vs 90%) and quantity (4% vs 100%), compared to wild type. TGA demonstrated increases in endogenous thrombin potential and peak height on addition of thrombomodulin (TM) in PC deficient compared to PC replete FVIII deficient plasma.

Conclusion: The partial quantitative PC deficiency in the patient resulted from a heterozygous pathogenic PROC p.Trp414Arg variant. Quantitative reduction in PC improved thrombin generation in FVIII deficient plasma upon addition of TM. Thus, this PROC variant was predicted to attenuate bleeding severity in HA by improving thrombin generation. Multigene panel sequencing permits the identification of genetic modifiers that result in naturally rebalanced haemostasis in inherited bleeding disorders.

Anticoagulants are essential to health care, yet their global supply is inherently fragile. Reliance on animal-derived heparin creates vulnerability to contamination, animal disease, and logistical disruption, whereas synthetic alternatives like warfarin and direct oral anticoagulants face mounting manufacturing and geopolitical risks. The COVID-19 pandemic exposed how these intersecting threats can converge during a crisis, causing critical shortages. To build resilience, a systemic shift is required: developing nonanimal-derived anticoagulants, diversifying production geographically, establishing protected supply corridors, reducing high-carbon footprint manufacturing processes, and creating equitable allocation frameworks. Anticoagulants must be recognized as essential medical assets, necessitating sustained investment and international coordination to ensure reliable access for all health systems, particularly before the next pandemic or global shock.

Background: It has become increasingly important to accurately identify cancer patients at high risk for venous thromboembolism (VTE) who could have greater benefit with anticoagulants. Cancer-associated genomic variants could have a potential clinical utility for prediction of VTE.

Methods: This study was a single-center observational study using the C-CAT database, the national datacenter for cancer genomic medicine in Japan, and evaluated 412 cancer patients who underwent comprehensive genome profiling with FoundationOne CDx at Kyoto University Hospital. We comprehensively investigated the association between cancer-associated genomic variants and VTE development.

Results: In the entire cohort, 77% had distant metastasis, and 90% were under chemotherapy. During a median follow-up period of 693 days, 59 patients (14.3%) developed VTE events. The cumulative incidence of VTE events after specimen collection was 26.0% at 5 years. In the multivariable Fine-Gray sub-distribution hazard models adjusted for age, sex, cancer type, metastasis, and chemotherapy at baseline, several genomic variants showed a trend toward an increased risk of VTE, including ERBB2 (HR 2.43, 95% CI 1.21-4.87), APC (HR 1.94, 95% CI 0.84-4.50), KRAS (HR 1.67, 95% CI 0.79-3.53), ATM (HR 1.64, 95% CI 0.74-3.65), and NOTCH1 (HR 1.51, 95% CI 0.73-3.11). However, no variants remained statistically significant after correction for multiple testing.

Conclusion: The current exploratory study identified several genomic variants potentially associated with a high risk of cancer-associated VTE, which may indicate potential clinical utility of comprehensive genomic profiling for accurate prediction of VTE events in cancer patients.

Background: Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction to heparin caused by pathological immunoglobulin G (IgG) antibodies targeting platelet factor 4(PF4)/heparin antigenic complexes. Immune complexes (ICs) consisting of IgG antibodies and PF4/heparin bind to cellular FcγRIIA receptors to initiate prothrombotic cell signaling, including cytokine production and release.

Objective: This study sought to investigate the role of inflammasome cytokine production and release of IL-1β following HIT IC challenge.

Methods: Inflammasome cytokine release of IL-1β was measured in a whole blood assay, where healthy donor whole blood was incubated with PF4/heparin antigen and ICs consisting of either the monoclonal HIT-like antibody, KKO, or HIT patient plasma. Corresponding studies were conducted in peripheral blood mononuclear cells (PBMCs). Requirements for cellular FcγRIIA, complement pathway and inflammasome were determined with respective inhibitors. FcγRIIA transgenic mice with or without a genetic deletion of Nlrp3 were subjected to a FcγRIIA-dependent thrombosis model.

Results: Whole blood or PBMCs incubated with HIT ICs or HIT patient plasma elicited a significant increase in IL-1β secretion, which was dependent on FcγRIIA. IL-1β secretion required complement, as heat inactivated plasma or incubation with terminal complement inhibitors prevented cytokine release. Pretreatment of whole blood or PBMCs with the NLRP3 inhibitor MCC950 markedly reduced IL-1β secretion. Furthermore, transgenic mice given a FcγRIIA-dependent thrombotic challenge demonstrated a requirement for Nlrp3 to experience severe thrombocytopenia and thrombosis.

Conclusions: These data demonstrate that HIT ICs activate the inflammasome pathway in a FcγR/complement-dependent manner leading to IL-1β secretion which is a positive regulator of HIT pathology.

Background: The prothrombin time (PT) and activated partial thromboplastin time (APTT) are often considered routine tests in the assessment of perioperative bleeding risk. Physicians continue to order these tests, and major medical societies guidelines exhibit significant heterogeneity regarding the utility of coagulation tests as a general screening tool, despite many advocating for a risk-stratified approach over routine testing.

Objectives: This study aimed to assess for association between preoperative coagulation tests and bleeding events around elective surgery.

Methods: We conducted a systematic review of the literature. Three electronic databases were consulted MEDLINE, EMBASE, and EBM Reviews. Randomized trials and observational studies that assessed the predictive accuracy of preprocedural PT and APTT test results for perioperative bleeding were deemed eligible for inclusion. Outcomes included any bleeding events in the postoperative period.

Results: In total, 100 studies were included in our qualitative synthesis: otolaryngology (n = 15), minor surgeries and procedures (n = 15), neurosurgery (n = 17), orthopedic surgeries (n = 6), cardiac surgeries (n = 16), liver transplantation or hepatectomy (n = 20), general surgery, and other types of major surgery (n = 11). Qualitative synthesis demonstrated a weak or inconsistent association between PT or APTT and bleeding events. Associations were more frequently reported in studies involving patients with cirrhosis and/or neoplastic disease of the liver undergoing liver resection, transplantation, or major abdominal cancer debulking surgery.

Conclusion: Our findings confirm that coagulation testing results are not consistently associated with bleeding in minor surgeries and nearly all major elective surgeries. However, PT results might be associated with bleeding outcomes in patients with advanced liver disease undergoing major abdominal surgeries.

Background: More than 1 million people in the U.S. develop venous thromboembolism (VTE) annually, but little is known about long term mortality and causes of death after VTE.

Objectives: To investigate long-term mortality and causes of death after VTE, by VTE type.

Methods: Atherosclerosis Risk in Communities cohort participants free of VTE at baseline were followed from 1987-89 through 2019 for first-time VTE (unprovoked, cancer-provoked, or other-provoked) and death. The hazard ratios (HRs) of death and the proportion who died for each cause of death after first VTE were estimated by VTE type.

Results: The main causes of death after overall VTE were cancer (36%) and circulatory diseases (27%). After unprovoked VTE, 36% died of circulatory diseases and 13% of cancer. Those values were similar for other-provoked VTE. For cancer-provoked VTE, 80% died of cancer and 11% of circulatory diseases. Five years after overall VTE, the HR of death was 2.7 (95% confidence interval [CI]: 2.6-3.0). This HR was highest for cancer-provoked VTE (HR, 5.5, 95% CI: 4.3-6.9). Those with unprovoked (HR: 1.9; 95% CI: 1.7-2.2) and other provoked VTE (HR: 2.4; 95% CI: 2.0-2.7) also had elevated risk. Ten years after VTE, those with any VTE, unprovoked VTE, and other-provoked VTE had a 60% higher risk of death (95% CI for each 1.3-1.5 to 1.9).

Conclusions: Long-term mortality risk after VTE in this U.S. cohort was higher than among people without VTE. Apart from those with cancer-provoked VTE, circulatory diseases were the primary cause of death after VTE.

Background: Although fibrinolytic therapy is effective for treating acute myocardial infarction or ischemic stroke, its use is limited by a significant risk of bleeding, highlighting the need for safer alternatives. Antiplasmin serves as the primary endogenous inhibitor of plasmin, thereby protecting fibrin from degradation after plasminogen activation. Inhibition of antiplasmin may enhance fibrinolysis, potentially eliminating the need for exogenous lytic agents such as tissue-type plasminogen activator (tPA) or tenecteplase.

Objectives: Determine whether BAY3018250, a monoclonal antibody directed against human and rabbit antiplasmin, accelerates plasminogen activation in vitro and promotes thrombolysis in vivo.

Methods: Binding of BAY3018250 to antiplasmin was determined by surface plasmon resonance, ELISA, and SDS-PAGE. Its effect on plasminogen activation was determined in purified and plasma systems. Lysis of jugular vein thrombi was evaluated in rabbits.

Results: BAY3018250 bound antiplasmin with high affinity, decreased plasmin inhibition, blocked the formation of plasmin-antiplasmin complexes, and augmented plasma clot lysis mediated by tPA or tenecteplase. BAY3018250 promoted plasmin generation in human plasma. In rabbits with preformed jugular vein thrombi, administration of BAY3018250 enhanced both endogenous and tenecteplase-induced thrombolysis, without increasing blood loss from standardized ear incisions. Notably, 15 mg/kg BAY3018250 combined with 0.1 mg/kg tenecteplase achieved superior thrombolysis compared with 0.5 mg/kg tenecteplase alone, with no additional risk of bleeding.

Conclusions: These findings indicate that BAY3018250 is a promising candidate for promoting endogenous or plasminogen activator-induced fibrinolysis.

Background: Antiphospholipid syndrome (APS) is a thrombotic auto-immune disease, treated with long-term anticoagulation to prevent thrombotic complications. APS is defined by persistent presence of antiphospholipid antibodies (aPL). However, certain patients lose aPL positivity over time. The risk of thrombotic recurrence after aPL negativization is unknown; hence, the necessity of continued anticoagulation in this subset of patients is uncertain.

Objectives: To assess thrombotic recurrence in patients with APS and aPL negativization after discontinuation of anticoagulation.

Methods: In this systematic review and meta-analysis, Pubmed, Embase, Web of Science, Cochrane Library, Emcare and Academic Search Premier were searched for studies including patients with APS, aPL negativization and discontinued anticoagulation. Risk of bias was assessed using the ROBINS-I tool. The primary outcome was the pooled incidence rate (95%-CI) for thrombotic recurrence after discontinuation of anticoagulation, estimated using a random-effects Poisson regression model.

Results: In total, 55 patients from 6 relevant observational cohort studies fulfilled the inclusion criteria. Heterogeneity amongst these studies was found in the definition of aPL negativization, timing of treatment discontinuation and follow-up. A total of 3 venous thrombotic recurrences were reported, resulting in a pooled thrombotic recurrence rate of 1.61 per 100 person-years (95%-CI 0.52-4.98).

Conclusions: Interpretation of the thrombotic recurrence rate in patients with APS and aPL negativization found in this meta-analysis is limited by the nature and quality of the included data. Future research should assess whether aPL negativiation could be a factor to take into account when reevaluating the need for long-term anticoagulation in certain low-risk APS patients.