Given the growing number of patients receiving direct oral anticoagulant (DOAC), patients requiring rapid neutralization is also increasing in case of major bleedings or urgent surgery/procedures. ...Idarucizumab is commercialized as a specific antidote to dabigatran while andexanet alfa has gained the Food and Drug Administration and the European Medicines Agency approval as an oral anti-factor Xa inhibitors antidote. Other antidotes or hemostatic agents are still under preclinical or clinical development, the most advanced being ciraparantag. DOAC plasma levels measurement allows to appropriately select patient for antidote administration and may prevent unnecessary prescription of expensive molecules in some acute clinical settings. However, these tests might be inconclusive after some antidote administration, namely andexanet alfa and ciraparantag. The benefit of laboratory monitoring following DOAC reversal remains unclear. Here, we sought to provide an overview of the key studies evaluating the safety and efficacy of DOAC reversal using the most developed/commercialized specific antidotes, to discuss the potential role of the laboratory monitoring in the management of patients receiving DOAC specific antidotes and to highlight the areas that deserve further investigations in order to establish the exact role of laboratory monitoring in the appropriate management of DOAC specific antidotes.
Anticoagulation monitoring and specific reversal agent targets
DOAC: direct oral anticoagulant; dTT: diluted thrombin time; ECA: ecarin chromogenic assay; ECT: ecarin cloting time. Display omitted
•Antidotes for direct oral anticoagulant (DOAC) reversal have been developed.•The role of laboratory monitoring in DOAC reversal using antidotes is unclear.•Dabigatran level prior to idarucizumab could predict reversal outcome.•Oral FXa inhibitor levels cannot be easily measured following andexanet alfa.•DOAC measurement using commercialized assays is not possible after ciraparantag.
The impact of estrogen and testosterone on atherosclerotic cardiovascular disease is well known, but the role of the gonadotropins follicle-stimulating hormone (FSH), luteinizing hormone (LH), and ...prolactin (PRL) to some extent remain less studied.
To explore the angiogenic potential of gonadotropins on endothelial colony-forming cells (ECFCs).
We examined the effects of various doses of gonadotropins on ECFCs obtained from cord blood by assessing colony number, proliferation, migration, and sprouting ability. Moreover, we studied thrombin generation in ECFCs exposed to gonadotropins by performing a thrombin generation assay. Finally, we determined the levels of circulating gonadotropins in 30 men, to exclude the effect of estrogen, with lower extremity arterial disease (LEAD), in comparison with age- and sex-matched controls.
Exposure to FSH, LH, or PRL resulted in an increase in ECFC migration but showed no effect on proliferation or ECFC commitment from cord blood mononuclear cells. Using a three-dimensional fibrin gel assay, we showed that ECFC sprouting was significantly enhanced by gonadotropins. Exposure to FSH also increased the thrombin generation of ECFCs exposed to FSH. Finally, FSH and LH levels in men with LEAD were higher than those in controls.
Gonadotropins increase ECFC-related angiogenesis and may be involved in thrombin generation in cardiovascular disease. Gonadotropins may act as biomarkers; moreover, we hypothesize that gonadotropin-blocking strategies may be a novel interesting therapeutic approach in atherosclerotic cardiovascular disease.
Circulating antiphospholipid antibodies (APL) induce vascular injury and endothelial dysfunction, which are associated with thrombotic events and/or fetal loss. We developed a model in which ...calibrated automated thrombin generation (CAT) is carried out in wells lined with cultured endothelial cells. Then we investigated how far b2GP1 antibodies provoked thrombin generation (TG) enhancing effects in these cells and/or in blood platelets.
Thrombin generation induced by different concentrations of tissue factor and different levels of endothelial aortic cell confluence was investigated by calibrated automated thrombogram. Endothelial cells were incubated with the purified anti-β2glycoprotein I antibodies of patients with antiphospholipid syndrome (APS). Platelet free plasma and platelet rich plasma were used to study thrombin generation in endothelial cells and platelet reactivity, respectively.
Endothelial cell confluence was negatively correlated with thrombin generation which was dependent on the concentration of APL incubated. Activation of endothelial cells with APL significantly increased thrombin generation triggered by PFP. Triggering by PRP increased thrombinogram parameters. Moreover, anti-β2glycoprotein I antibodies incubated with platelet significantly amplified thrombin formation in PRP and induced platelet activation without tissue factor.
In this in vitro study, we demonstrate the feasibility of using thrombin generation test in cultured endothelial cells and suggest the need to realize adjustments to standardize results. The mechanism of prothrombotic states in APS requires endothelial dysfunction and platelet activation. The quantification of thrombin formation shows that APL incubation induces endothelial injury in cultured cells amplified by platelets.
•Thrombin generation is realizable in cultured endothelial cells.•When endothelial cells are incubated with APL thrombin generation is increased.•When platelets are incubated with APL thrombin generation is increased in EC.•APL had the capacity to induce direct platelet activation.
Coagulation factor XII (FXII) plays a role in thrombin generation, fibrinolysis, inflammation, angiogenesis, chemotaxis and diapedesis. FXII deficiency is not associated with bleeding risk unlike ...other coagulation factors.
We investigated thrombin generation assay (TGA) profile modification in FXII deficiency and the correlation with TGA and deficiency severity. TGA was performed in platelet poor plasma (PPP) with tissue factor (1 pmol/L) and phospholipid (4 µmol/L) standardized concentration. Thrombin generation profiles were compared in 54 patients with FXII deficiency, 25 healthy controls and 23 patients with hemophilia A (factor VIII (FVIII) deficiency. Patients with FXII deficiency were classified in three groups based on FXII activity (30–50%, 10–29%, <10%). FVIII deficiency was included as a bleeding control group.
As expected, we found a correlation between FXII deficiency and activated partial thromboplastin time (aPTT). A decrease of thrombin generation was observed in healthy controls and all FXII deficiency groups. A decrease of endogenous thrombin potential (ETP), peak and velocity was observed in patients with FVIII deficiency compared to FXII deficiency. A decrease of thrombin generation was noted in patients with FXII deficiency and bleeding history compared to patients with FXII deficiency and thrombosis history.
In this study, thrombin generation profiles were not sensitive to FXII deficiency. TGA could distinguish bleeding and thrombotic tendency in FXII deficiency. Our results should therefore be considered as exploratory and deserve confirmation.
Afibrinogenemia with two compound heterozygous mutations in FGA gene Feugray, Guillaume; Billoir, Paul; Casini, Alessandro ...
Haemophilia : the official journal of the World Federation of Hemophilia,
September 2021, 2021-Sep, 2021-09-00, 20210901, Letnik:
27, Številka:
5
Journal Article
Idiopathic pulmonary fibrosis (IPF) is a severe, progressive and irreversible lung disease constantly associated with a major vascular remodeling process. Endothelial colony-forming cells (ECFCs) are ...human vasculogenic cells proposed as a cell therapy product or liquid biopsy in vascular disorders. Since the link between IPF and thrombosis has been largely proposed, the aim of our study was to explore hypercoagulability states in ECFCs from patients with IPF. We performed Thrombin generation assay (TGA) in cord blood (CB)-ECFCs, peripheral blood (PB)-ECFCs and IPF-ECFCs. Endogenous thrombin potential and peak were higher in IPF-ECFCs compared to CB-ECFCs and PB-ECFCs. As thrombin generation in ECFCs was increased, we evaluated anticoagulant proteins expressed on ECFCs membrane and identified thrombomodulin and EPCR. We found a significant decrease of both anticoagulant proteins at membrane using flow cytometry. This study is the first to examine ECFC thrombin generation in IPF. This new finding strongly argues for a role of ECFC in IPF pathophysiology and thrombotic related disorders in IPF. Graphical Abstract.
Immature platelets (IP) are the youngest circulating platelets, released from megakaryocytes, and demonstrating increased dimensions, significant RNA content, and enhanced activity. Immature platelet ...research focuses on a differential diagnostic help in patients with thrombocytopenia. The objectives of this study were to compare the variability of IP in citrate and EDTA samples, and to determine stability over time.
Fifty-six patients were included for comparison between EDTA and citrate whole blood sample collection. Among the patients, 28 had thrombocytopenia (platelet count < 150G/L). Platelet measurement impedancemetry and fluorimetry were performed with Sysmex XN-9000. The immature platelet fraction (IPF) and absolute immature platelet count (A-IPC) were determined with a fluorescent method.
The mean value of platelet count with fluorescence was, in EDTA sample, 215 ± 171 and, in citrate sample, 153 ± 118 G/L. No significant difference was observed between IPF between EDTA and citrate (7.74 ± 6.68% vs. 8.45 ± 7.37%, p = 0.69), respectively. With the Bland-Altman analysis, the mean difference in the EDTA sample, between 1 and 24 h, was 8.06 ± 6.96% and 8.73 ± 7.12% for IPF, whereas in the citrate sample, between 1 and 6 h, it was 8.60 ± 7.29% and 7.54 ± 6.97%, for IPF. Comparing 1 h EDTA sample with 6 h citrate sample, the variance ratio was 0.974 (95% CI: 0.864-1.084) in IPF.
We confirmed the potential to conduct IP measurements up to 24 h in the EDTA sample and IPF measurements in the citrate sample for up to 6 h. These results may be useful for the use of IPF, which is a promising parameter whose interest in clinical practice and standardization is not yet well defined.
Factor V Leiden (FVL) mutation is the most common genetic risk factor for venous thromboembolism. In families with a history of thrombosis, FVL can be present in 18%. Thrombin generation test is ...commonly used as an evaluation tool of thrombotic risk. The objective of this study was to evaluate the thrombogenic potential of FVL in asymptomatic carriers and in patients with personal or familial history of thrombosis. This was a retrospective single center study including 160 patients. Among them, 43 had personal history of thrombosis and 117 had familial history of thrombosis. Thrombin generation (TG) was realized in frozen platelet poor plasma with 1 pM of tissue factor and 4 µM of phospholipid. FVL mutation was associated with a global increase of TG. No difference was observed between patients with provoked thrombosis and patients with first-degree familial history of thrombosis (endogenous thrombin potential (ETP): 1501.0 ± 316.4 nM min and thrombin peak: 253.4 ± 71.5 nM vs. 1520.4 ± 283.8 nM min and 268.6 ± 68.0 nM). An increase of TG was observed in patients with unprovoked thrombosis (n = 23) and in patients with provoked thrombosis (n = 20) (ETP: 1819.5 ± 319.8 nM min and peak: 332.3 ± 55.8 nM). In the unprovoked thrombosis group, patients with a pulmonary embolism had a higher ETP than patients with deep vein thrombosis (DVT) (2036 ± 343 nM min vs. 1707 ± 261 nM min). With a predictive score formula (s = 0.1315 × Age + 0.0105 × ETP) with a threshold of 22.1 as risk to develop an unprovoked thrombosis among patients with second-degree familial history. The results of our analysis suggest that measurement of thrombin generation in patients with FVL mutation may identify subjects with an increased risk of unprovoked thrombosis. Further studies are needed to examine the usefulness of predicting thrombotic presentation in asymptomatic carriers.
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