Journal of Thrombosis and Thrombolysis最新文献

Growing evidence suggests inflammatory bowel disease (IBD) is linked to ischemic stroke (IS); however, the results are inconclusive. Therefore, it remains uncertain whether the association between IBD and IS is causal. Herein, we performed a bidirectional Mendelian randomization (MR) study to examine the causal association of IBD with IS. We obtained summary-level data for IBD and IS from several publicly released genome-wide association studies to conduct a two-sample bidirectional Mendelian randomization (MR) analysis. Herein, the inverse-variance weighted method was utilized as the primary approach. Then, we applied the weighted median and MR-Egger estimators for the follow-up sensitivity analyses. In addition, the MR-Egger intercept test was performed to detect the potential directional pleiotropy. Genetically predicted IBD was not causally associated with IS and IS subtypes (IS: OR = 0.99, 95% CI 0.98-1.01, p = 0.49; large artery atherosclerosis stroke: OR = 1.00, 95% CI: 0.96-1.05, p = 0.88; cardioembolic stroke: OR = 0.99, 95% CI 0.96-1.03, p = 0.75; small-vessel occlusion stroke: OR = 1.02, 95% CI 0.99-1.05, p = 0.16). Moreover, we did not find a significant causal effect of UC or CD on IS and IS subtypes. Furthermore, there was no significant association observed between IS and IBD in the reverse MR analysis. The estimates were consistent across sensitivity analyses. Our MR analysis does not support a bidirectional causal association between IBD and IS, despite observational studies reporting an association of IBD with IS.

Animal models of thrombosis play a critical role in research, helping us understand the mechanisms of hemostasis and thrombus formation, as well as in the screening of anti-thrombotic drugs. This study aimed to evaluate the safety profile of two anticoagulants in murine research and to assess coagulation parameters, including prothrombin time (PT) and activated partial thromboplastin time (aPTT), using the VETSCAN^® VSpro coagulation analyzer in wild-type (C57BL/6) mice following administration of anticoagulants. Two experiments were conducted involving a total of sixty wild-type mice that received two common anticoagulants. Warfarin was administered in the drinking water at varying dosages, while dabigatran was incorporated into a custom-chow diet at two dosages (10 mg/g and 15 mg/g chow). The VSpro was used to establish a reference range for PT and aPTT values in untreated wild-type mice and to monitor coagulation changes in mice undergoing anticoagulant therapy. Dabigatran was well tolerated at both concentrations (10 mg/g and 15 mg/g chow), while warfarin was safe at a concentration of 2.5 mg/L, resulting in a doubling of PT and aPTT compared to baseline levels. Although the VSpro effectively detected coagulation abnormalities in murine models, certain limitations were observed, including out-of-range measurements in cases of coagulopathy. This study provides insights into safe anticoagulant dosages for murine models, supporting the use of dabigatran at 10 mg/g and 15 mg/g chow and warfarin at 2.5 mg/L. The VSpro analyzer was able to monitor coagulation parameters under these conditions, making it a feasible tool for murine research.

Thrombin generation (TG) is reduced after cardiac surgery using cardiopulmonary bypass (CPB), contributing to coagulopathy and bleeding. Plasma transfusion or four-factor prothrombin complex concentrate (PCC) are commonly used to treat coagulopathic bleeding after CPB without knowledge of how each may restore TG. To determine the effect of PCC infusion on restoration of thrombin generation compared with plasma transfusion, we performed a laboratory-based secondary analysis of a randomized, controlled trial of adult patients undergoing cardiac surgery to assess efficacy and safety of 4 F-PCC versus plasma for treatment of perioperative coagulopathic bleeding after CPB. Participants were randomized to receive either PCC (15 IU/kg) or plasma (10-15 ml/kg) after separation from CPB. Participant blood samples were obtained at pre-specified serial timepoints, with laboratory assays for TG and factor levels subsequently performed. The primary outcome was change in thrombin generation (TG) parameters after each randomized treatment through postoperative day 5. Secondary outcomes included serially derived clotting factor levels. Of 100 randomized participants, 99 were included in this laboratory analysis (PCC group, N = 51; plasma group, N = 48). After treatment, participants in the PCC group compared with those in the plasma group showed higher endogenous thrombin potential (ETP, Median, Interquartile range, IQR: 688 [371-1069] vs. 1088 [550-1691] nM minutes, P = 0.01), a greater increase din ETP (P = 0.002) and peak TG (P = 0.01) in the timepoints between heparin reversal and after treatment administration. Both groups demonstrated similar values in all TG assays by postoperative day 1 (P > 0.05). The PCC group also demonstrated higher levels of proteins C, S, and Factors II, VII, IX and X, early after treatment (P < 0.001 for all comparisons). Antithrombin levels were initially higher in the plasma group after treatment (Median, IQR: 66% [61-71%] vs. 56% [51-65%], P = 0.002) but differences did not persist beyond postoperative day 3. In this laboratory analysis from a recent randomized trial in adult cardiac surgery, PCC administration restored thrombin generation more rapidly than plasma in the early postoperative period without laboratory evidence of hypercoagulability. ClinicalTrials.gov identifier: NCT02557672 [1].

The use of weight-based unfractionated heparin (UFH) infusions is the standard of care in hospital management of venous thromboembolism (VTE). Initial dosing strategies for UFH in older adults and higher body weight patients remain uncertain given differences in pharmacokinetics and concerns for over-anticoagulation. Methods: This was a single-center, retrospective, pre-post study involving older adults aged ≥ 65 years and patients weighing ≥ 100 kg with suspected or confirmed VTE to determine if the use of adjusted body weight (AdjBW)-based UFH regimens improves time to therapeutic anti-Xa levels compared to total body weight (TBW)-based regimens Patients received weight-based UFH infusions, dosed according to either TBW or AdjBW, to target a therapeutic anti-Xa level. Each cohort consisted of 40 patients, stratified by whether they met age or weight criteria to ensure equal representation of elderly and higher body weight patients between cohorts. The median time to therapeutic anti-Xa levels was shorter in the AdjBW group compared to the TBW group (13.6 h versus 20.9 h; point estimate 5.3 h (95% CI 0.2 to 9.9)). This finding was driven by those aged ≥ 65 years and those who received a bolus dose at the start of the infusion. Among older adults and higher weight adults with suspected or confirmed VTE, the use of AdjBW to guide heparin infusion initiation was associated with shorter time to therapeutic anti-Xa levels. This finding driven by the older adult sample and the subgroup analyses did not find a statistically significant difference in time to therapeutic anti-Xa levels in higher body weight patients aged less than 65 years.

Treatments with different antithrombotic agents can affect micro-rheological variables, such as red blood cell (RBC) deformability and aggregation. Since the effect of dual antiplatelet and anticoagulant (APAC) treatment on micro-rheology is unknown, we aimed to investigate the effect of different intravenous doses of APAC on hematological and micro-rheological variables in a porcine model. Two groups were formed (APAC group, Control group), and blood was collected from the animals at preset intervals. Hematological variables, RBC deformability, and aggregation were measured. We observed an improvement in the RBC deformability measured at a low shear stress range (< 3 Pa). However, after both doses, a decrease in the maximal elongation index of RBC values occurred in the APAC group. RBC aggregation increased after APAC bolus dose, while it gradually and dose-dependently decreased. Supposedly, the improvement in RBC deformability that was observed at a lower shear rate could facilitate aggregation. Administration of APAC and unfractionated heparin (UFH) caused comparable changes in hematological and hemorheological variables. Signs of thrombosis or bleeding did not occur. APAC and UFH had comparable micro-rheological effects.

Combined deficiency of coagulation factor V (FV) and factor VIII (FVIII) is a rare bleeding disease caused by variants in either lectin mannose binding 1 (LMAN1) or multiple coagulation factor deficiency 2 (MCFD2) gene. Reducing the level of FVIII by inhibiting the LMAN1-MCFD2 complex may become a new anticoagulant approach. We aimed to find a new therapeutic option for anticoagulation by RNA interference (RNAi) targeting LMAN1 and MCFD2. siRNA sequences with cross-homology between mice and humans were designed based on LMAN1 or MCFD2 transcripts in NCBI and were screened with the Dual-Luciferase reporter assay. The optimal siRNAs were chemically modified and conjugated with three N-acetylgalactosamine molecules (GalNAc-siRNA), promoting their targeted delivery to the liver. The expression of LMAN1 and MCFD2 in cell lines or mice was examined by RT-qPCR and western blotting. For the mice administered with siRNA, we assessed their coagulation function by measuring APTT and the activity of FVIII factor. After administration, siRNAs GalNAc-LMAN1 and GalNAc-MCFD2 demonstrated effective and persistent LMAN1 and MCFD2 inhibition. 7 days after injection of 3mg/kg GalNAc-LMAN1, the LMAN1 mRNA levels reduced to 19.97% ± 3.78%. MCFD2 mRNA levels reduced to 32.22% ± 13.14% with injection of 3mg/kg GalNAc-MCFD2. After repeated administration, APTT was prolonged and the FVIII activity was remarkably decreased. The tail bleeding test of mice showed that the amount of bleeding in the treated group did not significantly increase compared with the control group. Our study confirms that therapy with RNAi targeting LMAN1-MCFD2 complex is effective and can be considered a viable option for anticoagulation drugs. However, the benefits and potential risk of bleeding in thrombophilic mice model needs to be evaluated.

Factor XIIa (FXIIa) is a plasma serine protease within the contact activation pathway. Inhibiting FXIIa could offer a viable therapeutic approach for achieving effective and safer anticoagulation without the bleeding risks that accompany the use of existing anticoagulants. Therefore, we investigated the anticoagulant properties of an amidine-containing molecule (inhibitor 1) to identify a potential lead molecule for subsequent development of FXIIa inhibitors. Results indicated that inhibitor 1 primarily inhibits human FXIIa with an IC₅₀ value of ~30 µM. The inhibitor demonstrated variable selectivity against thrombin, factor IXa, factor Xa, factor XIa, and activated protein C. Michaelis-Menten kinetics indicated that the molecule is an active site inhibitor of FXIIa. Molecular modeling studies revealed that the molecule recognizes residues His57, Asp189, and Ala190 in FXIIa's active site. The inhibitor selectively and concentration-dependently prolonged the clotting time of human plasma under activated partial thromboplastin time assay conditions. The inhibitor did not exhibit significant cytotoxicity in human HEK293 cells and the in silico pharmacokinetics and toxicology data were comparable to known anticoagulants. This study introduces inhibitor 1 as a lead platform for further development as an anticoagulant to provide a more effective and safer approach to preventing and treating thromboembolic diseases.

Drugs targeting factor XI may offer an alternative to heparin for preventing blood clotting in extracorporeal circulation. We investigated the effects of abelacimab, a novel monoclonal antibody targeting factor XI. We collected whole blood samples into two bags (each 240 ml, control group: enoxaparin 1.2 mg, treatment group: enoxaparin 1.2 mg plus abelacimab 5 mg) and circulated in a hemodialysis device for up to 3 h. We performed whole blood aggregation and thromboelastometry at several time points. Time to filter clotting was the primary endpoint. We included 10 volunteers. Each volunteer's blood was split into two bags (containing enoxaparin +/- abelacimab) and used simultaneously on two hemodialysis devices. The treatment group's time to filter clotting was significantly prolonged (treatment: 180 min, IQR 180-180 vs. control: 120 min, IQR 97-147, p < 0.001), and the transmembrane pressure was significantly lower at the end of the circuit flow (treatment: 13 mmHg vs. control: 65 mmHg, p = 0.001). Fibrinogen levels and median platelet counts were preserved. Platelet aggregation was better preserved in the treatment group for ristocetin (p = 0.015), thrombin receptor activating peptide (p = 0.015), and arachidonic acid (p = 0.001). Thromboelastometry showed prolonged clotting times in the treatment group at the end of the experiment (INTEM, p < 0.001; HEPTEM, p = 0.001). Abelacimab prolonged the time to filter clotting in this ex vivo model of hemodialysis. This is an aggressive model due to the frequent re-circulation of blood and a lack of endothelial cells. These data provide support for testing abelacimab in patients on hemodialysis.