Thrombin generation assays to personalize treatment in bleeding and thrombotic diseases

Ex vivo evaluation of the effect of plasma-derived factor VIII/von Willebrand factor in patients with severe hemophilia A on emicizumab prophylaxis

Hemophilia A (HA) patients under emicizumab prophylaxis may require the concomitant use of procoagulant factors for breakthrough bleedings or immune tolerance induction (ITI). The aim of this study is to evaluate the ex vivo procoagulant effect of plasma-derived FVIII concentrates containing von Willebrand factor (pdFVIII/VWF) in samples from patients with severe HA without inhibitors on emicizumab prophylaxis. Samples from healthy controls (HC) and HA patients were drawn in sodium citrate plus corn trypsin inhibitor tubes and spiked with increasing concentrations of pdFVIII/VWF concentrates (10-400 IU/dL) (Fanhdi®/Alphanate®, Grifols), activated prothrombin complex concentrate (aPCC, 0.5 U/mL) or recombinant activated factor VII (rFVIIa, 0.9 µg/mL). Global coagulation was measured by rotational thromboelastometry (ROTEM) (clotting time [CT] and time to maximum clot formation velocity [MAXV-t]) and thrombin generation (TG) assay (thrombin peak [TP] and endogenous thrombin potential [ETP]). Samples from HA patients under emicizumab prophylaxis showed CT and MAXV-t values above HC levels, while TP and ETP were below HC levels. Ex vivo pdFVIII/VWF supplementation increased TP and ETP and shortened CT and MAXV-t dose-dependently. At 50 IU/dL (≈25 IU/kg), pdFVIII/VWF normalized clot formation and restored TG within HC normal range. The highest pdFVIII/VWF concentration (400 IU/dL) and rFVIIa did not result in an excessive procoagulant profile. However, aPCC induced ex vivo an excessive TG and markedly decreased ROTEM parameters (CT and MAXV-t). Coagulation parameters of both methods significantly correlated at baseline and with increasing concentrations of pdFVIII/VWF. High doses of pdFVIII/VWF concentrates, similar to those used for ITI, did not trigger a multiplying procoagulant effect to samples from HA patients on emicizumab prophylaxis, evidencing their low thrombotic risk in these patients.

Bleeding Symptoms in Pediatric Patients with Congenital FVII Deficiency and Correlation to Thrombin Generation Assay Parameters: A Single-Center Retrospective Analysis

Inherited factor VII deficiency is the most common rare bleeding disorder, affecting about 1/500,000 individuals without gender predilection. Most of the patients with FVII 20-50% are asymptomatic, but post-traumatic or post-surgical bleeding may often occur since there is not an exact correlation between FVII plasma levels and the bleeding phenotype. We enrolled 19 children and adolescents with FVII levels of 20-35% and 33 controls. Laboratory data collected included thrombin generation, prothrombin time, activated partial thromboplastin time, fibrinogen, and FVII levels. In our study, we found a statistical difference in the lag time ratio (p < 0.01) and tt-peak ratio (p < 0.05) between patients and controls but no difference in the other parameters, such as the endogenous thrombin potential (ETP). However, when we categorized patients, regardless of their bleeding scores, as presenting symptoms and having no symptoms, both the lag time ratio (p = 0.01) and tt-peak ratio (p < 0.05) were significantly different, and the vel. index % showed increased levels in patients without symptoms (p < 0.05). This study shows that thrombin generation may be a useful tool in assessing the risk of bleeding symptoms in children with an FVII deficiency categorized in the mild category (20-35%), although we cannot predict the severity of the bleeding.

Evaluation of coagulation by thromboelastography and a velocity curve in dogs with parvoviral enteritis

Canine parvoviral enteritis (CPE) has a high mortality rate in untreated dogs due to systemic inflammation and multi-organ dysfunction. The inflammatory process can lead to coagulation abnormalities. This study aimed to evaluate the coagulation status using thromboelastography (TEG) and assess the thrombin generation (TG) and clot dissolution using TEG-derived velocity curve (v-curve) parameters in dogs with CPE. It included 21 dogs with CPE and five healthy dogs. In addition to the clinico-haemato-biochemical examinations, the coagulation status was analysed using citrated venous blood samples with TEG. All the dogs with CPE met at least two criteria for systemic inflammatory response syndrome (SIRS). The comparison to healthy controls showed a statistically significant prolongation of reaction times (R time; P = 0.005) and times to the maximum rate of thrombus generation (TMRTG; P = 0.003). However, the times to the maximum rate of lysis (TMRL; P = 0.041) and total lysis (L; P = 0.024) decreased significantly. The TEG tracings showed coagulation states varying from hypocoagulation to hypercoagulation in dogs with CPE. These results showed that the v-curve derivate can be used to evaluate the coagulation in dogs with CPE, and it could be superior to the standard TEG variables for determining the low fibrinolytic activity. Thus, the v-curve parameters may provide a novel insight into the underlying mechanism and clinical treatment strategy of CPE-induced inflammation.

Comparative analysis of thrombin generation platforms for patients with coagulation factor deficiencies: A comprehensive assessment

INTRODUCTION

Thrombin generation assays (TGAs) assess the overall functionality of the hemostatic system and thereby provide a reflection of the hemostatic capacity of patients with disorders in this system. Currently, four (semi-)automated TGA platforms are available: the Calibrated Automated Thrombogram, Nijmegen Hemostasis Assay, ST Genesia and Ceveron s100. In this study, we compared their performance for detecting patients with congenital single coagulation factor deficiencies.

MATERIALS AND METHODS

Pooled patient samples, healthy control samples and normal pooled plasma were tested on all four platforms, using the available reagents that vary in tissue factor and phospholipid concentrations. The TGA parameters selected for analysis were peak height and thrombin potential. Results were normalized by using the calculated mean of healthy controls and a correction for between-run variation. Outcomes were presented as relative values, with the mean of healthy controls standardized to 100 %.

RESULTS

Across all platforms and reagents used, thrombin potentials and peak heights of samples with coagulation factor deficiencies were lower than those of healthy controls. Reagents designed for bleeding tendencies yielded the lowest values on all platforms (relative median peak height 19-32 %, relative median thrombin potential 19-45 %). Samples representing more severe coagulation factor deficiencies generally exhibited lower relative peak heights and thrombin potentials.

CONCLUSIONS

Thrombin generation assays prove effective in differentiating single coagulation factor deficient samples from healthy controls, with modest discrepancies observed between the platforms. Reagents designed for assessing bleeding tendencies, featuring the lowest tissue factor and phospholipid concentrations, emerged as the most suitable option for detecting coagulation factor deficiencies.

Quality of life and cost-effectiveness of different breast cancer surgery procedures: a Markov decision tree-based approach in the framework of Predictive, Preventive, and Personalized Medicine

Purpose

Breast cancer is a complex disease with heterogeneous outcomes that may benefit from the implementation of Predictive, Preventive, and Personalized Medicine (PPPM/3PM) strategies. In this study, we aimed to explore the potential of PPPM approaches by investigating the 10-year trends in quality of life (QOL) and the cost-effectiveness of different types of surgeries for patients with breast cancer.

Methods

This prospective cohort study recruited 144 patients undergoing breast conserving surgery (BCS), 199 undergoing modified radical mastectomy (MRM), and 44 undergoing total mastectomy with transverse rectus abdominis myocutaneous flap (TRAMF) from three medical centers in Taiwan between June 2007 and June 2010.

Results

All patients exhibited a significant decrease in most QOL dimension scores from before surgery to 6 months postoperatively (p < 0.05); however, from postoperative year 1 to 2, improvement in most QOL dimension scores was significantly better in the TRAMF group than in the BCS and MRM groups (p < 0.05). At 2, 5, and 10 years after surgery, the patients' QOL remained stable. In the Markov decision tree model, the TRAMF group had higher total direct medical costs than the MRM and BCS groups (US$ 32,426, US$ 29,487, and US$ 28,561, respectively) and higher average QALYs gained (7.771, 6.773, and 7.385, respectively), with an incremental cost-utility ratio (ICUR) of US$ 2,944.39 and US$ 10,013.86 per QALY gained.

Conclusions

TRAMF appeared cost effective compared with BCS and MRM, and it has been proved with considerable QOL improvements in the framework of PPPM. Future studies should continue to explore the potential of PPPM approaches in breast cancer care. By incorporating predictive models, personalized treatment plans, and preventive strategies into routine clinical practice, we can further optimize patient outcomes and reduce healthcare costs associated with breast cancer treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-023-00326-4.

Polydopamine-Coated Polycaprolactone Electrospun Nanofiber Membrane Loaded with Thrombin for Wound Hemostasis

Hemorrhagic shock is the primary cause of death in patients with severe trauma, and the development of rapid and efficient hemostatic methods is of great significance in saving the lives of trauma patients. In this study, a polycaprolactone (PCL) nanofiber membrane was prepared by electrospinning. A PCL-PDA loading system was developed by modifying the surface of polydopamine (PDA), using inspiration from mussel adhesion protein, and the efficient and stable loading of thrombin (TB) was realized to ensure the bioactivity of TB. The new thrombin loading system overcomes the disadvantages of harsh storage conditions, poor strength, and ease of falling off, and it can use thrombin to start a rapid coagulation cascade reaction, which has the characteristics of fast hemostasis, good biocompatibility, high safety, and a wide range of hemostasis. The physicochemical properties and biocompatibility of the PCL-PDA-TB membrane were verified by scanning electron microscopy, the cell proliferation test, the cell adhesion test, and the extract cytotoxicity test. Red blood cell adhesion, platelet adhesion, dynamic coagulation time, and animal models all verified the coagulation effect of the PCL-PDA-TB membrane. Therefore, the PCL-PDA-TB membrane has great potential in wound hemostasis applications, and should be widely used in various traumatic hemostatic scenarios.

Construction and application of thrombin-activated fluorescence-SERS dual-mode optical nanoprobes

Thrombin (TB) plays a key role in the pathological and physiological coagulation of diseases. In this work, a TB-activated fluorescence-surface-enhanced Raman spectroscopy (SERS) dual-mode optical nanoprobe (MRAu) was constructed by linking rhodamine B (RB)-modified magnetic fluorescent nanospheres with AuNPs through TB-specific recognition peptides. In the presence of TB, the polypeptide substrate could specifically be cleaved by TB, resulting in the weakening of SERS hotspot effect and the reduction of Raman signal. Meanwhile, the fluorescence resonance energy transfer (FRET) system was destroyed, and the RB fluorescence signal originally quenched by AuNPs was recovered. Using MRAu, SERS and fluorescence methods were combined to extend the TB detection range to 1-150 pM, and the detection limit was as low as 0.35 pM. In addition, the ability to detect TB in human serum also verified the effectiveness and practicality of the nanoprobe. The probe was also successfully employed to evaluate the inhibitory effect against TB of active components in Panax notoginseng. This study provides a new technical means for the diagnosis and drug development of abnormal TB-related diseases.

Abacavir use is associated with increased prothrombin conversion

There is ongoing debate as to whether abacavir (ABC) increases the risk for cardiovascular disease(CVD) in people living with HIV (PLHIV) and the mechanisms underlying this possible association. We recently showed that the use of an ABC-containing regimen was independently associated with increased thrombin generation (TG). In the present study, we aim to explore these findings further, by studying the mechanistical processes that underly the global thrombin generation test via thrombin dynamics analysis. Thrombin dynamics analysis can pinpoint the cause of increased thrombin generation associated with ABC-use either to the procoagulant prothrombin conversion pathway or the anticoagulant thrombin inactivation pathway. In this cross-sectional study, 208 virally suppressed PLHIV were included, of whom 94 were on a ABC-containing regimen, 92 on a tenofovir disoproxil fumarate (TDF)-containing regimen, and the remainder on other regimens. We used Calibrated Automated Thrombinography to measure thrombin generation and perform thrombin dynamics analysis. The total amount of prothrombin conversion, as well as the maximum rate of prothrombin conversion were significantly increased in PLHIV on an ABC containing regimen compared to other treatment regimens. The levels of pro- and anticoagulant factors were comparable, indicating that the ABC-induced changes affect the kinetics of prothrombin conversion rather than procoagulant factor levels. Moreover, Von Willebrand Factor (VWF), active VWF and VWF pro-peptide levels were significantly higher in PLHIV than controls without HIV. However, they did not differ between ABC and non-ABC treated participants.