Hamostaseologie最新文献

Hemophilia A is a hemorrhagic disease caused by a quantitative/qualitative deficiency of factor VIII. It is classified as severe, moderate, or mild based on its residual procoagulant activity. Long-term administration of FVIII promotes the development of neutralizing antibodies (inhibitors) in almost 30% of patients with the severe form of the disease. Currently, the role of regulatory T cells in the development of these antibodies is conflicting. Accordingly, the aim of this study was to determine the percentage of regulatory T cells subpopulations by flow cytometry in 10 healthy subjects, 15 patients with severe hemophilia without inhibitors, and 8 with inhibitors. No significant differences in the frequency of regulatory T cells subpopulations were found between hemophilia A patients with inhibitors versus hemophilia A patients without inhibitors or healthy subjects. Our results suggest that the role of the regulatory T cells populations on the development of inhibitors in adult patients with hemophilia A is questionable. However, further analysis of the etiological relevance of these cells requires future research.

Cytosolic calcium oscillations play a central role in platelet activation. However, signaling heterogeneity between platelets of the same individual, or between individuals, is poorly characterized. We utilized total internal reflection fluorescence microscopy of calcium fluorophore-loaded, surface-attached human platelets to monitor single-platelet calcium responses to collagen, ADP, and thrombin. For all activation types in healthy adult donors, four types of platelet calcium dynamics ("activation groups) were distinguished: (I) isolated spikes; (II) oscillations with a period of 3-10 s; (III) clusters of spikes following each other with calcium levels never returning to baseline; and (IV) a sustained high calcium level. The activation Groups I and II were predominant in the immobilized platelets of healthy adults (46 ± 22% and 33 ± 10%, respectively), with 18 ± 13% of platelets in Group III. Stimulation with ADP shifted the activation pattern, with Group I fraction falling to 15 ± 9% and Group III fraction rising to 43 ± 13% instead. For stimulation with ADP plus thrombin or collagen, Group III was predominant (71 ± 11% for thrombin, 46 ± 18% for collagen). A combination of all three agonists mainly produced Level III (69 ± 15%) and Level IV (18 ± 12%) platelets. Confocal microscopy revealed a gradual increase in all activation markers (including integrin activation, granule secretion, and spreading type) when one goes from Group I to Group IV. In the triple-negative breast cancer patients samples before therapy, the responses were shifted toward Group I indicating that their platelets were refractory. These results indicate the importance of platelet heterogeneity analysis and suggest a novel technique to investigate minor populations of refractory or hyperactive platelets.

Background: Persons with hemophilia (PwH) develop arthropathic changes due to recurrent hemarthroses. This study aimed to comprehensively investigate structural knee joint alterations in PwH, extended beyond synovitis and osteochondral abnormalities, and to compare findings with healthy controls (Con).

Methods: Bilateral knee ultrasound examinations were performed in 36 male PwH (severe A: 30, B: 2; moderate A: 3, B: 1; mean age: 47.1 ± 12.0) and 39 age-matched Con (mean age: 47.7 ± 12.8). A total of 26 landmarks and tissues, including synovium, osteophytes, ligaments, tendons, and bursae, were assessed quantitatively or semi-quantitatively. Clinical joint status was classified using the Hemophilia Joint Health Score, distinguishing between minorly (PwH-MI) and majorly (PwH-MA) affected joints.

Results: Synovium, osteophytes, ligaments, and bursae showed more pronounced alterations in PwH compared to Con. While the iliotibial band was slightly thicker in PwH (p = 0.023), the popliteus tendon (p = 0.001) and patellar tendon at the tibial insertion were significantly thinner. PwH-MA showed significant changes at all landmarks (p < 0.001), while PwH-MI demonstrated differences only in the lateral knee joint synovium (p = 0.006) compared to Con. Osteophytes and synovium were significantly thicker in PwH-MA than in PwH-MI.

Conclusion: The findings highlight the importance of assessing periarticular structures in PwH, as changes may contribute to functional impairments such as gait deviations. Further research is required to clarify the clinical implications.

The fibrinogen Dusart (p.Aα573Arg > Cys) is a dysfibrinogenemia associated with an increased risk of thrombosis. The aim of this study was to identify factors that could explain the hypofibrinolytic state associated with the Dusart mutation.The fibrin α2-antiplasmin (α2-AP) incorporation was quantified by a homemade enzyme-linked immunosorbent assay. The fibrin formation and lysis were studied by turbidity at 405 nm, and the global fibrinolytic capacity (GFC) with the Lysis timer device. The plasmin generation was assessed through an automated method. The clot growth was examined using Thrombodynamics. The clot structure was evaluated by measuring the permeation constant and scanning electron microscopy (SEM).The plasma levels of D-dimer, PAI-1, FXIII, PAP, and α2-AP were within the normal range, as was α2-AP incorporation into fibrin. By turbidity the patient's clots were almost transparent, and very resistant to fibrinolysis. The patient's GFC was 51 minutes compared with 45 minutes in control. The patient's endogenous plasmin potential and the peak plasmin were increased. The Thrombodynamics analysis revealed an increased lag time and a decreased initial velocity of patient's clot growth. The fibrin clot structure was characterized by a strong reduction in clot's flow (small pores size), and very thin fibers.The patient's procoagulant phenotype appears primarily driven by the formation of abnormally compact fibrin networks, leading to impaired perfusion and resistance to fibrinolysis, independent of any imbalance in fibrinolytic activators or inhibitors. These findings highlight the critical role of the fibrin clot structure in the thrombotic risk of this variant.

Efanesoctocog alfa (efa) is a recombinant coagulation factor VIII (FVIII) concentrate, engineered for improved extended half-life in hemophilia A treatment. Its design results in discrepancies in FVIII diagnostic tests, as has so far been demonstrated using spiked sample material (efa added to FVIII-deficient plasma). The aim of the present study was to evaluate FVIII assay discrepancies in post-infusion samples obtained from patients treated with efa. This retrospective analysis included 43 male patients on efa prophylaxis (26 on once weekly and 17 on twice weekly treatment scheme) summoned for determination of incremental recoveries. FVIII activity was measured at trough (3.5 or 7 days post-infusion) and peak levels (30 minutes post-infusion) using three diagnostic tests: two one-stage clotting assays (OSCAs) based on Actin FSL (AFSL) or Actin FS (AFS), and a chromogenic substrate assay (FVIII CSA). Incremental recoveries as determined by the recommended AFSL-based OSCA were found to be comparable between patient groups. At peak levels (64 to 214 IU/dL), comparable overestimation (1.9-fold) of plasma efa activity relative to Actin FSL-based OSCA was observed for both, the AFS-based OSCA and the FVIII CSA. In contrast, at trough levels (5 to 64 IU/dL), rate of overestimation relative to the AFSL-based OSCA results was found to be lower for the FVIII CSA (1.3-fold) when compared with the AFS-based OSCA (1.9-fold). Further analysis demonstrated different behavior of spiked and post-infusion samples within the FVIII CSA. Future studies will reveal underlying mechanisms and assess if drug-specific calibration will sufficiently correct for this phenomenon.

Despite enormous improvement in the management of patients with acute promyelocytic leukemia (APL), the distinctive coagulopathy observed at presentation in affected patients is often life-threatening. While hemorrhagic manifestations are well known and described in this setting, APL-related thromboses are underappreciated. Data regarding this complication are scarce showing variable incidence. Furthermore, risk factors for thrombosis are inconsistent and unreliable; so, differentiation of increased risk of hemorrhage from an increased thrombotic risk is quite difficult in the absence of adequate predictive scores. Besides, prophylactic use of anticoagulants and recombinant thrombomodulin are a matter of ongoing debate. Also, due to the common feature of thrombocytopenia and other hemorrhagic risks, patients with APL are excluded from trials analyzing anticoagulant prophylaxis in cancers; so, data from prospective trials are lacking. A detailed analysis of thrombotic risks in APL with the development of a reliable risk stratification model is needed to further improve the care of APL patients.

Second-generation thrombopoietin receptor agonists (TPO-RAs), romiplostim, eltrombopag, and avatrombopag, have been proved to be significant stimulators of megakaryopoiesis and, in the last decade, they have been incorporated in the treatment options against refractory immune thrombocytopenia in children and adults that do not respond to conventional therapy. Additionally, given their beneficial impact on hematopoiesis, they have successfully been applied in cases of non-immune thrombocytopenia, such as aplastic anemia, HCV-related thrombocytopenia, chronic liver disease, and most recently acute radiation syndrome. During the past years, a wide variety of clinical studies have been performed, in regard to the use of TPO-RAs in various thrombocytopenic settings, such as malignant hematology and hematopoietic stem cell transplantation, hereditary thrombocytopenias, and chemotherapy-treated patients with solid organ tumors. Although data indicate that TPO-RAs may be an effective and safe option for managing disease- or treatment-related thrombocytopenia in these patients, further research is needed to determine their efficacy and safety in these settings. Furthermore, recent studies have highlighted novel properties of TPO-RAs that render them as potential treatment candidates for reducing tumor burden or fighting infections. Herein, we discuss the potential novel applications of TPO-RAs and focus on data regarding their efficacy and safety in these contexts.

Changes in the hemostatic system during COVID infection lead to hypercoagulability. Numerous studies have evaluated hemostatic abnormalities in COVID patients during acute infection, in the period of hospitalization. However, the hemostatic status following hospital discharge has not been sufficiently assessed. Considering the importance of FVIII and D-dimer levels as markers for the assessment of thrombosis, our study aimed to evaluate changes in these markers, as well as the influence of patient's age and clinical presentation of COVID infection on those hemostatic markers in the post-COVID phase. This prospective study (July 2020 to December 2022) included 115 COVID patients, 68 (59%) with asymptomatic/mild and 47 (41%) with moderate/severe clinical presentation. Patient follow-up included laboratory evaluation of FVIII and D-dimer levels at 1, 3, and 6 months following the COVID infection. Three months after the COVID infection, elevated FVIII was recorded in 44% of younger versus 65% of older individuals, p = 0.05, respectively, and 30 versus 57% (p = 0.008) 6 months post-COVID infection. With a focus on clinical presentation, a higher number of patients with moderate/severe COVID had elevated FVIII activity, but a statistically significant difference was observed only for the 6 months (32% mild vs. 53% moderate/severe, p = 0.041) post-infection time point. Following a COVID infection, an increase in FVIII activity suggests a continued hypercoagulable state in the post-COVID period and correlates with elevated D-dimer levels. This increase in FVIII is more pronounced in patients with moderate/severe clinical picture and those patients older than 50 years.

In type 2 diabetes, platelets are likely affected by impaired long-term glycaemic control, but such pathophysiological links are poorly understood. This study thus compares platelet reactivity (i.e. agonist-evoked platelet reactions) in vitro with glycosylated haemoglobin (HbA1c), a measure commonly used for monitoring long-term metabolic control of type 2 diabetes. Elders with type 2 diabetes (n = 35) were divided according to HbA1c into groups (HbA1c-low and high) consisting of 17 and 18 subjects, respectively. For estimating mitochondria disintegration, a flow cytometer determined mitochondrial transmembrane potentials after whole blood agonist stimulation. The activating agents used were α-thrombin (10 μM) and collagen (0.15 μg/mL). The same apparatus analysed the fibrinogen receptor activity, lysosomal exocytosis (surface lysosomal-associated membrane protein 1), and platelet procoagulant characteristics (membrane-attached annexin V) after stimulation. In type 2 diabetes, after in vitro agonist stimulation, platelet mitochondria injury was higher in the HbA1c-high group. The fibrinogen receptor, lysosomal secretion, and the creation of procoagulant platelets proved to be uninfluenced by HbA1c.

Major bleeding (MB) is a serious complication in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI). Although its association with long-term adverse outcomes is well documented, the impact of in-hospital MB on early cardiovascular prognosis remains incompletely characterized.To investigate the association between in-hospital MB and major adverse cardiovascular events (MACE) in patients with ACS treated with PCI.We conducted a retrospective cohort study on 829 consecutive ACS patients who underwent successful PCI between January 2021 and December 2023. MB was defined as Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding events. MACE was defined as a composite of all-cause mortality, recurrent myocardial infarction, ischemic stroke, urgent target vessel revascularization, or new-onset/decompensated heart failure with left ventricular ejection fraction (LVEF) <30%. Clinical data and outcomes were extracted from hospital records and independently adjudicated.MB occurred in 4.5% of patients (n = 37). The incidence of in-hospital MACE was significantly higher among patients with MB compared to those without (40.5% vs. 8.1%, p < 0.001). In multivariate logistic regression, MB was the strongest independent predictor of in-hospital MACE (OR: 12.43, 95% CI: 3.43-44.98, p < 0.001), followed by reduced LVEF (OR per % increase: 0.794, 95% CI: 0.747-0.843, p < 0.001), age, and white blood cell count.In-hospital MB is a potent and independent predictor of early MACE in patients with ACS undergoing PCI. These findings emphasize the need for careful risk stratification, bleeding prevention strategies, and individualized antithrombotic management in this high-risk population.