TH open : companion journal to thrombosis and haemostasis最新文献

The development of inhibitors to von Willebrand factor (VWF) is a rare but potentially serious complication of VWF replacement therapy in patients with von Willebrand disease (VWD). Patients who develop VWF inhibitors may become unresponsive and/or may develop severe anaphylactic reactions to VWF concentrates. Data on inhibitor development and management in VWD remain limited, and better understanding of inhibitor development is an important goal in VWD management. The WIL-31 study demonstrated the efficacy and safety of prophylaxis with wilate, a plasma-derived VWF/factor VIII (pdVWF/FVIII) concentrate, in children and adults with VWD of all types. The annualized bleeding rate (ABR) was reduced by 84% with wilate prophylaxis compared with on-demand treatment, and prophylaxis was well tolerated. No inhibitors developed during the WIL-31 study. Here, we report two brothers with type 3 VWD who at the 6-month visit were found to have VWF inhibitors, which on further investigation were found to have already been present before the study. Despite the presence of inhibitors, neither patient showed any clinical symptoms, and prophylaxis with wilate led to a ≥85% reduction in ABR in both boys compared with on-demand treatment.

Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone encoded by the SERPINH1 gene, has emerged as a groundbreaking focus in thrombosis research. Recent findings published in "Science" have revolutionized our understanding of thrombosis, identifying HSP47 as a critical mediator in a new thrombosis target for treatment. This discovery not only unveils a novel pathway in thrombosis but also opens new avenues for therapeutic intervention. HSP47's significance extends beyond thrombosis, influencing pathological processes such as fibrosis and cancer. In fibrosis, its upregulation promotes collagen deposition, while its dysregulation in osteogenesis imperfecta (OI) Type X underscores the protein's indispensable role in collagen biosynthesis. The therapeutic challenge lies in balancing HSP47 inhibition to reduce fibrotic burden without impairing its essential physiological functions. In cancer, HSP47 plays dual roles. It supports tumor progression through collagen stabilization and metastasis facilitation while contributing to tissue repair under hyperthermia treatment combined with radiotherapy or chemotherapy. However, its overexpression can exacerbate tumor aggressiveness via mechanisms such as angiogenesis and epithelial-mesenchymal transition. This review emphasizes the pivotal discovery of HSP47's thrombogenic role and its broader implications in disease biology. These findings mark a paradigm shift in thrombosis research and underscore the potential of HSP47 as a target in diverse pathological contexts, from platelet-driven diseases to fibrotic and oncological disorders.

Background: Venous thromboembolism (VTE) can considerably limit patients' functioning and quality of life. Using patient-reported outcome measures (PROMs), the full impact of VTE on individual patients can be captured.

Methods: To evaluate the experiences of patients and healthcare professionals with the routine use of PROMs for VTE patients visiting the outpatient clinic, a mixed-methods study was performed at Leiden University Medical Center, the Netherlands. VTE PROMs were incorporated into routine care since March 2023, through a digital application sending patients invitations to complete PROMs. Quantitative and qualitative data were obtained from semi-structured interviews with patients and involved healthcare professionals. The NoMAD (normalization measure development) questionnaire was used to assess the implementation process from the professionals' perspective. Patients aged ≥18 years who experienced VTE and completed PROMs at two follow-up time points during ≥3 months follow-up and VTE patients who did not complete PROMs at both time points were asked to participate.

Results: Eight patients (five completed PROMs; three did not) and four professionals were interviewed. Both patients and professionals experienced the use of PROMs as neutral to predominantly positive (lower limit 3 on a scale of 1-5). All professionals valued the effects of PROMs on their work. Most patients felt the questionnaires contained too many questions. Suggestions to improve the completion rate, accessibility, PROMs content, and the digital tool were shared.

Conclusion: PROMs were believed to provide additional value during preparation for the appointment and during the consultation. The first experiences of patients and professionals, tending toward positive, can be used to improve PROMs application and support implementation in routine thrombosis care.

Objective: To describe an innovative anticoagulation strategy in a 20-year-old woman with innate jejunal atresia and ultrashort bowel syndrome who was dependent on long-term parenteral nutrition and suffered from multiple venous thrombotic events and bleeding complications since infancy.

Design: Single-patient case report.

Setting: Dresden University Hospital, Dresden, Germany.

Patient: Being fully CVC-dependent since birth, our patient repeatedly developed catheter-related thrombosis (CRT) since infancy and was treated with daily low-molecular-weight heparin injections for more than 15 years. Despite this, clotting, severe gastrointestinal bleeding, and osteoporosis remained a persistent problem, causing numerous hospitalizations over the years, significant developmental delays, and a decline in the patient's body mass index (BMI). A short period of rivaroxaban treatment had to be stopped owing to acute gastrointestinal bleeding. After the failure of all approved anticoagulant concepts, compassionate use access was granted to the investigational drug osocimab, a human monoclonal antibody inhibitor of factor XIa. Hereditary FXI deficiency as well as FXI inhibition in animal models have been shown to reduce arterial and venous thrombosis without increasing bleeding. Consistent with this, short-term osocimab treatment has shown clinical efficacy in preventing postoperative venous thromboembolism after knee replacement surgery and in reducing dialysis conduit clotting compared with placebo in patients undergoing hemodialysis, without increasing the rate of clinically relevant bleeding versus comparators. After initiating osocimab, the patient experienced no further clotting complications, and bleeding decreased in frequency and severity. The patient's BMI decline immediately stopped; her weight increased by over 10% in the subsequent 20 months, and menstruation started 3 months later without signs of menorrhagia. Now, with 2.5 years of uninterrupted exposure outside of a clinical trial, this patient has experienced the longest duration of factor XIa inhibition to date. She continues to receive osocimab under the compassionate use program and maintains a positive change in her well-being and quality of life.

Background: Patients taking direct oral anticoagulants (DOACs) often present complicated scenarios following major bleeding, stroke, or emergency surgery. Rapid whole blood assays of DOAC levels would aid clinical decisions such as the need for DOAC reversal.

Methods: We developed a single-use, storage-stable, eight-channel microfluidic device to estimate factor Xa (FXa) inhibitor (apixaban or rivaroxaban) levels in venous thromboembolism or atrial fibrillation patients. The assay simultaneously measured whole blood clotting dynamics on collagen/tissue factor (TF; wall shear rate, 200 ^-1 ) under four ex vivo conditions: no-treatment control, high dose Factor Xa inhibition, low dose or high dose FXa reversal agent (andexanet alfa). Fibrin and platelet deposition dynamics were monitored via two-color epifluorescence microscopy. Plasma samples were also evaluated by LC-MS/MS for DOAC concentrations.

Results: Experiments with healthy volunteer blood spiked with DOAC verified device performance (DOAC IC ₅₀ ∼120 nM) and confirmed that andexanet alfa added to healthy donor blood had no off-target effect on platelet or fibrin signal. Patient whole blood monitored for 15 to 25 minutes (17 minutes mean runtime) allowed calculation of functional DOAC concentrations ranging from 2 to 500 nM that correlated well with LC-MS/MS determination of apixaban or rivaroxaban (R ²  = 0.7 or 0.9, respectively). Platelet dysfunction was not observed in any patient on DOAC. For a threshold of 100 nM DOAC, the area under the curve (AUC) was found to be 0.881 for apixaban and 0.933 for rivaroxaban.

Conclusion: Microfluidic testing of whole blood can provide a rapid estimate of DOAC levels over the on-therapy range.

Background: Hypercoagulability is a risk factor for venous thromboembolism (VTE). Thrombin generation (TG) is a global coagulation assay that measures an individual's clotting tendency. We hypothesise that slow-onset TG (achieved by using a low procoagulant stimulus or an inhibitor of coagulation) is the optimal responsive TG method for detecting hypercoagulability.This study aimed to compare different TG assay conditions with respect to VTE risk and assess the risk of the first VTE.

Materials and methods: Basal TG at low tissue factor (TF) concentration and high TF concentration in the presence and absence of activated protein C (APC) were measured in plasma samples from 2,081 patients with first VTE and 2,908 healthy controls from the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis (MEGA) study. TG parameters and normalised activated protein C sensitivity ratio (nAPCsr) were categorised into quartiles as measured in the controls. We calculated odds ratios (ORs) with 95% confidence intervals (CIs) of the first VTE for different TG categories.

Results: Under all assay conditions the thrombin peak height was associated with VTE risk: peak height of >75th percentile, at low TF OR 6.8 (95% CI 5.5-8.3), at high TF, OR 3.0 (95% CI 2.5-3.6), and at high TF + APC, OR 3.8 (95% CI 3.2-4.5), all compared with a peak height of <25th percentile obtained in controls. An increased nAPCsr (higher resistance to APC) was also associated with VTE risk, OR 3.4 (95% CI 2.8-4.1).

Conclusion: Increased TG is associated with the risk of first VTE, particularly when triggered with a low procoagulant stimulus.

Antiphospholipid syndrome (APS) is a rare autoimmune disorder characterized by thromboembolic and obstetric complications in the presence of persistent antiphospholipid antibodies (aPL). Treatment aims to prevent recurrent thrombosis, primarily using anticoagulation therapy with vitamin K antagonists (VKA). Monitoring of VKA therapy relies on the International Normalized Ratio (INR), which can be assessed using point-of-care testing (POCT). However, in a subset of APS patients with a high-risk aPL profile, the POCT-INR is falsely elevated, which might lead to underdosing of VKA and subsequent high risk of recurrent thrombosis. This case report describes two female patients with triple-positive thrombotic APS receiving VKA therapy. Both patients underwent biweekly paired INR measurements via POCT-INR and venous INR methods. Despite significant discrepancies, a strong individual linear correlation was observed: r  = 0.77 (95% confidence interval [CI]: 0.54-0.99, p  < 0.001) and r  = 0.93 (95% CI: 0.88-0.97, p  < 0.001), respectively. These findings suggest that individualized correction factors could be developed to improve the accuracy of POCT-INR measurements, thereby optimizing VKA dosing in these patients.

Cancer-associated thrombosis affects between 1 and 20% of all patients diagnosed with cancer and is associated with significant morbidity and a poorer prognosis. Risk assessment scores exist which include the measurement of biomarkers, and which aim to identify patients at a higher risk of developing thrombotic events, but these are poor predictors and rarely used in routine clinical practice. VEGF is a potent angiogenic factor, produced by tumour cells, and released by platelets and is essential for tumour growth and progression. It also plays a role in the promotion of thrombosis through platelet activation and adhesion, and by inducing the expression of tissue factor. Therefore, the potential of VEGF to be used as a biomarker to predict cancer-associated thrombosis requires further investigation. This study reviewed the published literature to determine whether circulating VEGF levels are associated with increased risk of venous thromboembolism in patients with cancer. PubMed and OVID databases were systematically searched according to PRISMA guidelines for relevant papers using the keywords "cancer" AND "thrombosis" AND "VEGF" up to July 2023. Inclusion and exclusion criteria were applied. Seven papers (1,528 participants) were identified and included in the meta-analysis, three of which (922 participants) measured VEGF before a thrombotic event, and the remaining four (606 participants) measured VEGF at the time of the thrombosis. Our results showed that although plasma and serum VEGF tended to be higher in those who subsequently developed thrombosis than those who did not (mean difference 70.2 pg/mL for serum, and 11.44 pg/mL for plasma VEGF, 95% CI -2.39-25.73, p  = 0.10), this was not found to be statistically significant. However, analysis of VEGF following blood sampling at the time of thrombosis showed a stronger statistically significant association between increased VEGF levels and presence of thrombosis (mean difference 117.02 pg/mL for serum, and 116.6 pg/mL for plasma VEGF, 95% CI 55.42-190.82, p  = 0.0004). Based on current studies, whilst it is increased at the time of thrombosis, VEGF is not effective as a predictive biomarker of CAT.