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Chandran R, Tohit ERM, Stanslas J, Salim N, Mahmood TMT, Rajagopal M. Shifting Paradigms and Arising Concerns in Severe Hemophilia A Treatment. Semin Thromb Hemost 2024; 50:695-713. [PMID: 38224699 DOI: 10.1055/s-0043-1778103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
The management of hemophilia A has undergone a remarkable revolution, in line with technological advancement. In the recent past, the primary concern associated with Factor VIII (FVIII) concentrates was the risk of infections, which is now almost resolved by advanced blood screening and viral inactivation methods. Improving patients' compliance with prophylaxis has become a key focus, as it can lead to improved health outcomes and reduced health care costs in the long term. Recent bioengineering research is directed toward prolonging the recombinant FVIII (rFVIII) coagulant activity and synthesising higher FVIII yields. As an outcome, B-domain deleted, polyethylene glycolated, single-chain, Fc-fused rFVIII, and rFVIIIFc-von Willebrand Factor-XTEN are available for patients. Moreover, emicizumab, a bispecific antibody, is commercially available, whereas fitusiran and tissue factor pathway inhibitor are in clinical trial stages as alternative strategies for patients with inhibitors. With these advancements, noninfectious complications, such as inhibitor development, allergic reactions, and thrombosis, are emerging concerns requiring careful management. In addition, the recent approval of gene therapy is a major milestone toward a permanent cure for hemophilia A. The vast array of treatment options at our disposal today empowers patients and providers alike, to tailor therapeutic regimens to the unique needs of each individual. Despite significant progress in modern treatment options, these highly effective therapies are markedly more expensive than conventional replacement therapy, limiting their access for patients in developing countries.
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Affiliation(s)
- Rubhan Chandran
- Department of Pathology, Haematology Unit, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia
- Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Biology, UCSI University, Jalan Puncak Menara Gading, Taman Connaught, Cheras, Kuala Lumpur, Malaysia
| | - Eusni R Mohd Tohit
- Department of Pathology, Haematology Unit, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia
| | - Johnson Stanslas
- Department of Medicine, Pharmacotherapeutics Unit, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Norazlinaliza Salim
- Centre of Foundation Studies for Agricultural Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Integrated Chemical Biophysics Research, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Tuan M T Mahmood
- Faculty of Pharmacy, The National University of Malaysia (UKM), Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia
| | - Mogana Rajagopal
- Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Biology, UCSI University, Jalan Puncak Menara Gading, Taman Connaught, Cheras, Kuala Lumpur, Malaysia
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Mehic D, Assinger A, Gebhart J. Utility of Global Hemostatic Assays in Patients with Bleeding Disorders of Unknown Cause. Hamostaseologie 2024. [PMID: 38950624 DOI: 10.1055/a-2330-9112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/03/2024] Open
Abstract
Bleeding disorder of unknown cause (BDUC) is a diagnosis of exclusion after exhaustive evaluation of plasmatic coagulation and platelet function. This review explores the utility of global hemostatic assays as confirmatory tests and in elucidating the pathophysiology of BDUC. Unlike traditional hemostatic tests that focus on coagulation factors, global assays are conducted both in plasma and also whole blood. These assays provide a more comprehensive understanding of the cell-based model of coagulation, aid in the identification of plasmatic factor abnormalities that may reduce hemostatic capacity, and allow for the assessment of impaired platelet-endothelial interactions under shear stress, as well as hyperfibrinolytic states. While clinical tests such as skin bleeding time and global assays such as PFA-100 exhibit limited diagnostic capacity, the role of viscoelastic testing in identifying hemostatic dysfunction in patients with BDUC remains unclear. Thrombin generation assays have shown variable results in BDUC patients; some studies demonstrate differences compared with healthy controls or reference values, whereas others question its clinical utility. Fibrinolysis assessment in vitro remains challenging, with studies employing euglobulin clot lysis time, plasma clot lysis time, and fluorogenic plasmin generation yielding inconclusive or conflicting results. Notably, recent studies suggest that microfluidic analysis unveils shear-dependent platelet function defects in BDUC patients, undetected by conventional platelet function assays. Overall, global assays might be helpful for exploring underlying hemostatic impairments, when conventional hemostatic laboratory tests yield no results. However, due to limited data and/or discrepant results, further research is needed to evaluate the utility of global assays as screening tools.
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Affiliation(s)
- Dino Mehic
- Clinical Division of Hematology and Hemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Alice Assinger
- Institute of Vascular Biology and Thrombosis Research, Centre of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Johanna Gebhart
- Clinical Division of Hematology and Hemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
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Valke LLFG, Cloesmeijer ME, Mansouritorghabeh H, Barteling W, Blijlevens NMA, Cnossen MH, Mathôt RAA, Schols SEM, van Heerde WL. Pharmacokinetic-Pharmacodynamic Modelling in Hemophilia A: Relating Thrombin and Plasmin Generation to Factor VIII Activity After Administration of a VWF/FVIII Concentrate. Eur J Drug Metab Pharmacokinet 2024; 49:191-205. [PMID: 38367175 PMCID: PMC10904421 DOI: 10.1007/s13318-024-00876-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2024] [Indexed: 02/19/2024]
Abstract
BACKGROUND Hemophilia A patients are treated with factor (F) VIII prophylactically to prevent bleeding. In general, dosage and frequency are based on pharmacokinetic measurements. Ideally, an alternative dose adjustment can be based on the hemostatic potential, measured with a thrombin generation assay (TGA), like the Nijmegen hemostasis assay. OBJECTIVE The objective of this study was to investigate the predicted performance of a previously developed pharmacokinetic-pharmacodynamic model for FVIII replacement therapy, relating FVIII dose and FVIII activity levels with thrombin and plasmin generation parameters. METHODS Pharmacokinetic and pharmacodynamic measurements were obtained from 29 severe hemophilia A patients treated with pdVWF/FVIII concentrate (Haemate P®). The predictive performance of the previously developed pharmacokinetic-pharmacodynamic model was evaluated using nonlinear mixed-effects modeling (NONMEM). When predictions of FVIII activity or TGA parameters were inadequate [median prediction error (MPE) > 20%], a new model was developed. RESULTS The original pharmacokinetic model underestimated clearance and was refined based on a two-compartment model. The pharmacodynamic model displays no bias in the observed normalized thrombin peak height and normalized thrombin potential (MPE of 6.83% and 7.46%). After re-estimating pharmacodynamic parameters, EC50 and Emax values were relatively comparable between the original model and this group. Prediction of normalized plasmin peak height was inaccurate (MPE 58.9%). CONCLUSION Our predictive performance displayed adequate thrombin pharmacodynamic predictions of the original model, but a new pharmacokinetic model was required. The pharmacodynamic model is not factor specific and applicable to multiple factor concentrates. A prospective study is needed to validate the impact of the FVIII dosing pharmacodynamic model on bleeding reduction in patients.
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Affiliation(s)
- Lars L F G Valke
- Department of Hematology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
- Hemophilia Treatment Center, Nijmegen-Eindhoven-Maastricht, The Netherlands
| | - Michael E Cloesmeijer
- Department of Hospital Pharmacy-Clinical Pharmacology, Amsterdam University Medical Center, Location AMC, Amsterdam, The Netherlands
| | - Hassan Mansouritorghabeh
- Clinical Research Development Unit, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Wideke Barteling
- Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Nicole M A Blijlevens
- Department of Hematology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Marjon H Cnossen
- Department of Pediatric Hematology and Oncology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Ron A A Mathôt
- Department of Hospital Pharmacy-Clinical Pharmacology, Amsterdam University Medical Center, Location AMC, Amsterdam, The Netherlands
| | - Saskia E M Schols
- Department of Hematology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
- Hemophilia Treatment Center, Nijmegen-Eindhoven-Maastricht, The Netherlands
| | - Waander L van Heerde
- Department of Hematology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
- Hemophilia Treatment Center, Nijmegen-Eindhoven-Maastricht, The Netherlands.
- Enzyre BV, Novio Tech Campus, Nijmegen, The Netherlands.
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Tarandovskiy ID, Ovanesov MV. The effect of factor XIa on thrombin and plasmin generation, clot formation, lysis and density in coagulation factors deficiencies. Thromb Res 2024; 233:189-199. [PMID: 38101192 DOI: 10.1016/j.thromres.2023.11.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/21/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023]
Abstract
INTRODUCTION Growing evidence supports the importance of factor (F) XI activation for thrombosis and hemostasis as well as inflammation and complement systems. In this study, we evaluated the effect of activated FXI (FXIa) on the detection of factor deficiencies by global hemostasis assays of thrombin generation (TG), plasmin generation (PG), and clot formation and lysis (CFL). MATERIALS AND METHODS An absorbance and fluorescence microplate assay was used to simultaneously observe TG, PG, and CFL in FV-, FVII-, FVIII-, and FIX-deficient plasmas supplemented with purified factors. Coagulation was initiated with tissue factor with or without FXIa in the presence of tissue plasminogen activator. Thrombin and plasmin peak heights (TPH and PPH), maximal clot density (MCD), times to clotting (CT), thrombin and plasmin peaks (TPT and PPT) and clot lysis (LyT) and a new parameter, clot lifetime (LiT), were evaluated. RESULTS TG/CFL were elevated by the FXIa at low FV (below 0.1 IU/mL), and at FVIII and FIX above 0.01 IU/mL. FXIa affected PG only at low FV and FVII. At high factor concentrations, FXIa reduced MCD. Thrombin and plasmin substrates had effect on CT, LyT, LiT and MCD parameters. CONCLUSIONS FXIa reveals new relationships between TG, PG and CFL parameters in factor deficiencies suggesting potential benefits for discrimination of bleeding phenotypes.
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Affiliation(s)
- Ivan D Tarandovskiy
- Center of Biologics Evaluation and Research, U.S. Food and Drug Administration, United States of America
| | - Mikhail V Ovanesov
- Center of Biologics Evaluation and Research, U.S. Food and Drug Administration, United States of America.
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Valke LLFG, Verhagen MJA, Mulders BTPM, Polenewen R, Blijlevens NMA, Jansen JH, Mansouritorghabeh H, Elsheikh E, Reipert BM, Turecek PL, O'Donnell JS, Rijpma SR, Schols SEM, van Heerde WL, Meijer D. The Nijmegen ultra-sensitive Bethesda Assay detects very low-titer factor VIII inhibitors in patients with congenital and acquired hemophilia A. Thromb Res 2023; 231:112-120. [PMID: 37844518 DOI: 10.1016/j.thromres.2023.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/23/2023] [Accepted: 10/04/2023] [Indexed: 10/18/2023]
Abstract
BACKGROUND An inhibitor can develop in congenital hemophilia A (HA) patients against exogenous infused factor (F)VIII, whereas in acquired HA (AHA) inhibitors initially develop against endogenous FVIII. Inhibitors can be detected with the Nijmegen Bethesda Assay (NBA), which has an international cut-off level of 0.60 Nijmegen Bethesda Units/mL (NBU/mL). Thereby, very low-titer inhibitors may remain undetected. AIM To describe the design and validation of the Nijmegen ultra-sensitive Bethesda Assay (NusBA) for the detection of very low-titer inhibitors. METHODS The NusBA is a modification of the NBA in which the ratio of patient plasma to normal pooled plasma is changed from 1:1 to 9:1. Analytical validation was performed according to the CLSI EP10 guideline in order to determine trueness and reproducibility. Clinical validation was performed in two cohorts of congenital HA patients (82 adults) with pharmacokinetic data and four AHA patients. The limit of quantitation (LOQ) was determined by measuring plasma samples spiked with inhibitor levels in the low range (0.05-0.80 NBU/mL). RESULTS The LOQ for the NusBA was 0.10 NusBU/mL, with a coefficient of variation of 24.2 %. Seven (8.5 %) congenital HA patients had a positive NusBA result, of which only one was detected with the NBA. There was no correlation between NusBA and FVIII half-life. In three of the AHA patients the NusBA remained positive, when the NBA became negative. DISCUSSION The NusBA is able to detect very low-titer FVIII inhibitors of ≥0.10 NBU/mL. Thereby, it may have added value in early inhibitor detection and therapy adjustments in patients with congenital HA and AHA.
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Affiliation(s)
- Lars L F G Valke
- Department of Hematology, Radboud University Medical Center, Nijmegen, the Netherlands; Hemophilia Treatment Center, Nijmegen-Eindhoven-Maastricht, the Netherlands
| | - Marieke J A Verhagen
- Department of Hematology, Radboud University Medical Center, Nijmegen, the Netherlands; Hemophilia Treatment Center, Nijmegen-Eindhoven-Maastricht, the Netherlands; Laboratory of Hematology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Bart T P M Mulders
- Laboratory of Hematology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Robert Polenewen
- Laboratory of Hematology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nicole M A Blijlevens
- Department of Hematology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Joop H Jansen
- Laboratory of Hematology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Hassan Mansouritorghabeh
- Central Diagnostic Laboratories, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Einas Elsheikh
- Irish Centre for Vascular Biology, School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons, Ireland
| | | | - Peter L Turecek
- Baxalta Innovations GmbH, A Member of the Takeda Group of Companies, Vienna, Austria
| | - James S O'Donnell
- Irish Centre for Vascular Biology, School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons, Ireland; National Coagulation Centre, St James's Hospital, Dublin, Ireland
| | - Sanna R Rijpma
- Laboratory of Hematology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Saskia E M Schols
- Department of Hematology, Radboud University Medical Center, Nijmegen, the Netherlands; Hemophilia Treatment Center, Nijmegen-Eindhoven-Maastricht, the Netherlands
| | - Waander L van Heerde
- Department of Hematology, Radboud University Medical Center, Nijmegen, the Netherlands; Hemophilia Treatment Center, Nijmegen-Eindhoven-Maastricht, the Netherlands; Enzyre BV, Novio Tech Campus, Nijmegen, the Netherlands.
| | - Danielle Meijer
- Laboratory of Hematology, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
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Goedhart TMHJ, Janssen A, Mathôt RAA, Cnossen MH. The road to implementation of pharmacokinetic-guided dosing of factor replacement therapy in hemophilia and allied bleeding disorders. Identifying knowledge gaps by mapping barriers and facilitators. Blood Rev 2023; 61:101098. [PMID: 37321952 DOI: 10.1016/j.blre.2023.101098] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 04/02/2023] [Accepted: 05/07/2023] [Indexed: 06/17/2023]
Abstract
Clinical guidelines and expert groups recommend the use of pharmacokinetic (PK)-guided dosing of factor replacement therapy for the treatment of bleeding disorders, especially for patients with hemophilia. Although PK-guided dosing is increasingly applied, it is generally not considered standard clinical practice. The aim of this scoping review is to map barriers and facilitators for the implementation of PK-guided dosing in clinical practice and to identify knowledge gaps. A literature search was performed and 110 articles were included that describe PK-guided dosing in patients with bleeding disorders, mostly hemophilia A. We defined two overarching themes, efficacy and feasibility, and discuss five topics within each theme. For each topic, barriers, facilitators and knowledge gaps were described. Although consensus was found with regard to some topics, contradicting reports were found for others, especially with respect to the efficacy of PK-guided dosing. These contradictions highlight the need for future research to elucidate current ambiguities.
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Affiliation(s)
- Tine M H J Goedhart
- Department of Pediatric Hematology and Oncology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, the Netherlands.
| | - A Janssen
- Department of Clinical Pharmacology - Hospital Pharmacy, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands.
| | - Ron A A Mathôt
- Department of Clinical Pharmacology - Hospital Pharmacy, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands.
| | - Marjon H Cnossen
- Department of Pediatric Hematology and Oncology, Erasmus MC Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, the Netherlands.
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7
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Erez O, Gotsch F, Jung E, Chaiworapongsa T, Gudicha DW, Suksai M, Gallo DM, Chaemsaithong P, Bosco M, Al Qasem M, Meyyazhagan A, Than NG, Romero R. Perturbations in kinetics of the thrombin generation assay identify women at risk of preeclampsia in the first trimester and provide the rationale for a preventive approach. Am J Obstet Gynecol 2023; 228:580.e1-580.e17. [PMID: 36368431 PMCID: PMC10149548 DOI: 10.1016/j.ajog.2022.11.1276] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/03/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Activation of the coagulation system and increased thrombin generation have been implicated in the pathophysiology of preeclampsia, and this rationale supports the administration of low-molecular-weight heparin to prevent this syndrome in patients at risk. Yet, randomized trials of this prophylactic measure have yielded contradictory results. A possible explanation is that only a subset of patients with preeclampsia have excessive thrombin generation and would benefit from the administration of low-molecular-weight heparin. Therefore, the key questions are whether and when patients who subsequently develop preeclampsia present evidence of abnormal thrombin generation. OBJECTIVE This study aimed to determine (1) the kinetics of thrombin generation throughout gestation in women with a normal pregnancy and in those with early and late preeclampsia, and (2) the diagnostic performance of in vivo thrombin generation parameters to predict the development of preeclampsia. STUDY DESIGN This retrospective, nested case-control study was based on a prospective longitudinal cohort of singleton gestations. Cases comprised women who developed preeclampsia (n=49), and controls consisted of patients with a normal pregnancy (n=45). Preeclampsia was classified into early-onset (n=24) and late-onset (n=25). Longitudinal changes in the parameters of the thrombin generation assay (lag time, time to peak thrombin concentration, peak thrombin concentration, endogenous thrombin generation, and velocity index) throughout gestation were compared between the study groups, and normal pregnancy percentiles were derived from the control group. We tested whether a single parameter or a combination of parameters, derived from the kinetics of thrombin generation, could identify patients who subsequently developed preeclampsia. Time-related parameters <10th percentile were considered short, and concentration-related parameters >90th percentile were considered high. RESULTS (1) Patients who developed preeclampsia (early- and late-onset) had abnormal thrombin generation kinetics as early as 8 to 16 weeks of pregnancy; (2) patients with a combination of a short lag time and high peak thrombin concentration at 8 to 16 weeks of pregnancy had an odds ratio of 43.87 for the subsequent development of preeclampsia (area under the curve, 0.79; sensitivity, 56.8%; specificity, 92.7%; positive likelihood ratio, 7.76); (3) at 16 to 22 weeks of gestation, patients with a combination of a short lag time and a high velocity index had an odds ratio of 16 for the subsequent development of preeclampsia (area under the curve, 0.78; sensitivity, 62.2%; specificity, 92.5%; positive likelihood ratio, 8.29). CONCLUSION During early pregnancy, the thrombin generation assay can identify the subset of patients at a greater risk for the development of preeclampsia owing to accelerated and enhanced production of thrombin. This observation provides a rationale for testing the efficacy of low-molecular-weight heparin in this subset of patients. We propose that future research on the efficacy of low-molecular-weight heparin and other interventions targeting the coagulation system to prevent preeclampsia should be focused on patients with abnormal kinetics of thrombin generation.
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Affiliation(s)
- Offer Erez
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI; Department of Obstetrics and Gynecology, Emek Medical Center, Afula, Israel
| | - Francesca Gotsch
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Eunjung Jung
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Tinnakorn Chaiworapongsa
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Dereje W Gudicha
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Manaphat Suksai
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Dahiana M Gallo
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Piya Chaemsaithong
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI; Department of Obstetrics and Gynecology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Mariachiara Bosco
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Malek Al Qasem
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Arun Meyyazhagan
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Nandor Gabor Than
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Systems Biology of Reproduction Research Group, Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary; Maternity Private Clinic, Budapest, Hungary; First Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
| | - Roberto Romero
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI; Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI; Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI; Detroit Medical Center, Detroit, MI.
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8
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Verhagen MJ, van Heerde WL, van der Bom JG, Beckers EA, Blijlevens NM, Coppens M, Gouw SC, Jansen JH, Leebeek FW, van Vulpen LF, Meijer D, Schols SE. In patients with hemophilia, a decreased thrombin generation profile is associated with a severe bleeding phenotype. Res Pract Thromb Haemost 2023; 7:100062. [PMID: 36865907 PMCID: PMC9971314 DOI: 10.1016/j.rpth.2023.100062] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 12/20/2022] [Accepted: 01/02/2023] [Indexed: 02/04/2023] Open
Abstract
Background Heterogeneity in clinical bleeding phenotype has been observed in hemophilia patients with similar FVIII or FIX activity levels. Thrombin generation and plasmin generation, as a global hemostasis assay, may contribute to a better prediction of which patients are at an increased risk of bleeding. Objectives The objective of this study was to describe the association between clinical bleeding phenotype and thrombin generation and plasmin generation profiles in patients with hemophilia. Methods The Nijmegen Hemostasis Assay, which simultaneously measures thrombin and plasmin generation, was performed in plasma samples of patients with hemophilia participating in the sixth Hemophilia in the Netherlands study (HiN6). Patients receiving prophylaxis underwent a washout period. A severe clinical bleeding phenotype was defined as a self-reported annual bleeding rate of ≥5, a self-reported annual joint bleeding rate of ≥3, or the use of secondary/tertiary prophylaxis. Results In total, 446 patients, with a median age of 44 years, were included in this substudy. Thrombin generation and plasmin generation parameters differed between patients with hemophilia and healthy individuals. The median thrombin peak height was 1.0 nM, 25.9 nM, 47.1 nM, and 143.9 nM in patients with severe, moderate, and mild hemophilia and healthy individuals, respectively. A severe bleeding phenotype was observed in patients with a thrombin peak height of <49% and a thrombin potential of <72% compared to healthy individuals, and was independent of the hemophilia severity. The median thrombin peak height was 0.70% in patients with a severe clinical bleeding phenotype and 30.3% in patients with a mild clinical bleeding phenotype. The median thrombin potentials for these patients were 0.06% and 59.3%, respectively. Conclusion A decreased thrombin generation profile is associated with a severe clinical bleeding phenotype in patients with hemophilia. Thrombin generation in combination with bleeding severity may be a better tool to personalize prophylactic replacement therapy irrespective of hemophilia severity.
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Affiliation(s)
- Marieke J.A. Verhagen
- Department of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands,Hemophilia Treatment Center Nijmegen-Eindhoven-Maastricht, Nijmegen, The Netherlands,Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Waander L. van Heerde
- Department of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands,Hemophilia Treatment Center Nijmegen-Eindhoven-Maastricht, Nijmegen, The Netherlands,Enzyre BV, Novio Tech Campus, Nijmegen, The Netherlands
| | - Johanna G. van der Bom
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Erik A.M. Beckers
- Department of Hematology, Maastricht University Medical Center, Maastricht, The Netherlands
| | | | - Michiel Coppens
- Department of Vascular Medicine and Haemophilia Treatment Center, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Samantha C. Gouw
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands,Pediatric Hematology, Emma Children’s Hospital, Amsterdam University Medical Center, University of Amsterdam, The Netherlands
| | - Joop H. Jansen
- Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frank W.G. Leebeek
- Department of Hematology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Lize F.D. van Vulpen
- Center for Benign Haematology, Thrombosis and Haemostasis, Van Creveldkliniek, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Daniëlle Meijer
- Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Saskia E.M. Schols
- Department of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands,Hemophilia Treatment Center Nijmegen-Eindhoven-Maastricht, Nijmegen, The Netherlands,Correspondence Saskia E. M. Schols, Department of Hematology, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, The Netherlands. @radboudumc_weet
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9
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Sidonio RF, Hoffman M, Kenet G, Dargaud Y. Thrombin generation and implications for hemophilia therapies: A narrative review. Res Pract Thromb Haemost 2022; 7:100018. [PMID: 36798897 PMCID: PMC9926221 DOI: 10.1016/j.rpth.2022.100018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 10/24/2022] [Accepted: 11/09/2022] [Indexed: 01/07/2023] Open
Abstract
Thrombin plays an essential role in achieving and maintaining effective hemostasis and stable clot formation. In people with hemophilia, deficiency of procoagulant factor (F)VIII or FIX results in insufficient thrombin generation, leading to reduced clot stability and various bleeding manifestations. A correlation has been found between the bleeding phenotype of people with hemophilia and the extent of thrombin generation, with individuals with increased thrombin generation being protected from bleeding and those with lower thrombin generation having increased bleeding tendency. The amount, location, and timing of thrombin generation have been found to affect the formation and stability of the resulting clot. The goal of all therapies for hemophilia is to enhance the generation of thrombin with the aim of restoring effective hemostasis and preventing or controlling bleeding; current treatment approaches rely on either replacing or mimicking the missing procoagulant (ie, FVIII or FIX) or rebalancing hemostasis through lowering natural anticoagulants, such as antithrombin. Global coagulation assays, such as the thrombin generation assay, may help guide the overall management of hemostasis by measuring and monitoring the hemostatic potential of patients and, thus, assessing the efficacy of treatment in people with hemophilia. Nevertheless, standardization of the thrombin generation assay is needed before it can be adopted in routine clinical practice.
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Affiliation(s)
- Robert F. Sidonio
- Aflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Atlanta, Georgia, USA,Department of Pediatrics, Emory University, Atlanta, Georgia, USA,Correspondence Robert F Sidonio, Aflac Cancer and Blood Disorders Center Children’s Healthcare of Atlanta, 1405 Clifton Road NE, Atlanta, GA 30322, USA. @nashgreenie
| | - Maureane Hoffman
- Department of Pathology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Gili Kenet
- The Israeli National Hemophilia Center and Thrombosis Unit, Sheba Medical Center, Tel Hashomer, Israel,The Amalia Biron Thrombosis Research Institute, Tel Aviv University, Tel Aviv, Israel
| | - Yesim Dargaud
- Unité d’Hémostase Clinique, Centre National de Reference de l'Hemophilie, Hôpital Cardiologique Louis Pradel, Université Lyon, Lyon, France
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10
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Valke LLFG, Rijpma S, Meijer D, Schols SEM, van Heerde WL. Thrombin generation assays to personalize treatment in bleeding and thrombotic diseases. Front Cardiovasc Med 2022; 9:1033416. [PMID: 36440026 PMCID: PMC9684194 DOI: 10.3389/fcvm.2022.1033416] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/26/2022] [Indexed: 07/30/2023] Open
Abstract
Treatment of bleeding and thrombotic disorders is highly standardized and based on evidence-based medicine guidelines. These evidence-based treatment schemes are well accepted but may lead to either insufficient treatment or over-dosing, because the individuals' hemostatic properties are not taken into account. This can potentially introduce bleeding or thrombotic complications in individual patients. With the incorporation of pharmacokinetic (PK) and pharmacodynamic (PK-PD) parameters, based on global assays such as thrombin generation assays (TGAs), a more personalized approach can be applied to treat either bleeding or thrombotic disorders. In this review, we will discuss the recent literature about the technical aspects of TGAs and the relation to diagnosis and management of bleeding and thrombotic disorders. In patients with bleeding disorders, such as hemophilia A or factor VII deficiency, TGAs can be used to identify patients with a more severe bleeding phenotype and also in the management with non-replacement therapy and/or bypassing therapy. These assays have also a role in patients with venous thrombo-embolism, but the usage of TGAs in patients with arterial thrombosis is less clear. However, there is a potential role for TGAs in the monitoring of (long-term) antithrombotic therapy, for example with the use of direct oral anticoagulants. Finally this review will discuss controversies, limitations and knowledge gaps in relation to the introduction of TGAs to personalize medicine in daily medical practice.
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Affiliation(s)
- Lars L. F. G. Valke
- Department of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
- Hemophilia Treatment Center, Nijmegen, Netherlands
| | - Sanna Rijpma
- Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Danielle Meijer
- Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Saskia E. M. Schols
- Department of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
- Hemophilia Treatment Center, Nijmegen, Netherlands
| | - Waander L. van Heerde
- Department of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
- Hemophilia Treatment Center, Nijmegen, Netherlands
- Enzyre BV, Novio Tech Campus, Nijmegen, Netherlands
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11
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Verhagen MJA, Valke LLFG, Schols SEM. Thrombin generation for monitoring hemostatic therapy in hemophilia A: A narrative review. J Thromb Haemost 2022; 20:794-805. [PMID: 35034413 PMCID: PMC9305107 DOI: 10.1111/jth.15640] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/17/2021] [Accepted: 01/10/2022] [Indexed: 11/29/2022]
Abstract
Patients with severe hemophilia A (HA) have an increased risk of spontaneous and trauma-related bleeding because of a congenital absence of factor VIII (FVIII). Most severe HA patients use prophylactic FVIII concentrate, the effect of which can be monitored with FVIII activity level measurement. However, FVIII activity level is less valuable in predicting the potential clinical bleeding risk. Some patients still experience breakthrough bleeds despite adequate FVIII trough levels, whereas others do not bleed with trough levels below threshold. This difference may be caused by inter-individual differences in pro- and anticoagulant factors, the so-called hemostatic balance. Thrombin generation assays (TGAs) measure the hemostatic balance as a whole. Thereby, the TGAs may be a better tool in the guidance and monitoring of treatment in HA patients. In addition, TGAs offer the opportunity to determine the response to bypassing agents and treatment with non-factor replacement therapy, in which FVIII activity assays are not suitable for monitoring. This review summarizes the current knowledge about monitoring different HA treatment modalities by TGA, as a single treatment option and when used in a concomitant fashion.
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Affiliation(s)
- Marieke J. A. Verhagen
- Department of HematologyRadboud University Medical CenterNijmegenThe Netherlands
- Hemophilia Treatment CenterNijmegen‐Eindhoven‐MaastrichtNijmegenThe Netherlands
| | - Lars L. F. G. Valke
- Department of HematologyRadboud University Medical CenterNijmegenThe Netherlands
- Hemophilia Treatment CenterNijmegen‐Eindhoven‐MaastrichtNijmegenThe Netherlands
| | - Saskia E. M. Schols
- Department of HematologyRadboud University Medical CenterNijmegenThe Netherlands
- Hemophilia Treatment CenterNijmegen‐Eindhoven‐MaastrichtNijmegenThe Netherlands
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12
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Bukkems LH, Valke LLFG, Barteling W, Laros-van Gorkom BAP, Blijlevens NMA, Cnossen MH, van Heerde WL, Schols SEM, Mathôt RAA. Combining factor VIII levels and thrombin/plasmin generation: a population pharmacokinetic-pharmacodynamic model for patients with hemophilia A. Br J Clin Pharmacol 2021; 88:2757-2768. [PMID: 34921439 PMCID: PMC9304184 DOI: 10.1111/bcp.15185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/07/2021] [Accepted: 12/05/2021] [Indexed: 11/28/2022] Open
Abstract
Aims Prophylactic treatment of haemophilia A patients with factor VIII (FVIII) concentrate focuses on maintaining a minimal trough FVIII activity level to prevent bleeding. However, due to differences in bleeding tendency, the pharmacokinetic (PK)‐guided dosing approach may be suboptimal. An alternative approach could be the addition of haemostatic pharmacodynamic (PD) parameters, reflecting a patient's unique haemostatic balance. Our aim was to develop a population PK/PD model, based on FVIII activity levels and Nijmegen Haemostasis Assay (NHA) patterns, a global haemostatic assay that measures thrombin/plasmin generation simultaneously. Methods PK/PD measurements were collected from 30 patients treated with standard half‐life FVIII concentrate. The relationship between FVIII activity levels and the thrombin/plasmin generation parameters (thrombin potential, thrombin peak height and plasmin peak height), were described by sigmoidal Emax functions. Results The obtained EC50 value was smallest for the normalized thrombin potential (11.6 IU/dL), followed by normalized thrombin peak height (56.6 IU/dL) and normalized plasmin peak height (593 IU/dL), demonstrating that normalized thrombin potential showed 50% of the maximal effect at lower FVIII activity levels. Substantial inter‐individual variability in the PD parameters, such as EC50 of thrombin potential (86.9%) was observed, indicating that, despite similar FVIII activity levels, haemostatic capacity varies significantly between patients. Conclusion These data suggest that dosing based on patients' individual PK/PD parameters may be beneficial over dosing solely on individual PK parameters. This model could be used as proof‐of‐principle to examine the application of PK/PD‐guided dosing. However, the relation between the PD parameters and bleeding has to be better defined.
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Affiliation(s)
- Laura H Bukkems
- Department of Hospital Pharmacy-Clinical Pharmacology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Lars L F G Valke
- Department of Hematology, Radboud University Medical Centre, Nijmegen, The Netherlands.,Hemophilia Treatment Centre, Nijmegen Eindhoven Maastricht, The Netherlands
| | - Wideke Barteling
- Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Britta A P Laros-van Gorkom
- Department of Hematology, Radboud University Medical Centre, Nijmegen, The Netherlands.,Hemophilia Treatment Centre, Nijmegen Eindhoven Maastricht, The Netherlands
| | - Nicole M A Blijlevens
- Department of Hematology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Marjon H Cnossen
- Department of Pediatric Hematology, Erasmus MC - Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Waander L van Heerde
- Hemophilia Treatment Centre, Nijmegen Eindhoven Maastricht, The Netherlands.,Enzyre BV, Novio Tech Campus, Nijmegen, The Netherlands
| | - Saskia E M Schols
- Department of Hematology, Radboud University Medical Centre, Nijmegen, The Netherlands.,Hemophilia Treatment Centre, Nijmegen Eindhoven Maastricht, The Netherlands
| | - Ron A A Mathôt
- Department of Hospital Pharmacy-Clinical Pharmacology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
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13
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Binder NB, Depasse F, Mueller J, Wissel T, Schwers S, Germer M, Hermes B, Turecek PL. Clinical use of thrombin generation assays. J Thromb Haemost 2021; 19:2918-2929. [PMID: 34592058 PMCID: PMC9292855 DOI: 10.1111/jth.15538] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 11/29/2022]
Abstract
Determining patient's coagulation profile, i.e. detecting a bleeding tendency or the opposite, a thrombotic risk, is crucial for clinicians in many situations. Routine coagulation assays and even more specialized tests may not allow a relevant characterization of the hemostatic balance. In contrast, thrombin generation assay (TGA) is a global assay allowing the dynamic continuous and simultaneous recording of the combined effects of both thrombin generation and thrombin inactivation. TGA thus reflects the result of procoagulant and anticoagulant activities in blood and plasma. Because of this unique feature, TGA has been widely used in a wide array of settings from both research, clinical and pharmaceutical perspectives. This includes diagnosis, prognosis, prophylaxis, and treatment of inherited and acquired bleeding and thrombotic disorders. In addition, TGA has been shown to provide relevant information for the diagnosis of coagulopathies induced by infectious diseases, comprising also disturbance of the coagulation system in COVID-19, or for the assessment of early recurrence in breast cancer. This review article aims to document most clinical applications of TGA.
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Affiliation(s)
| | | | | | | | | | | | - Björn Hermes
- DIN e.V. – DIN Standards Committee Medicine (NAMed)
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14
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Elalfy M, Elghamry I, Hassab H, Elalfy O, Andrawes N, El-Ekiaby M. Low-dose immune tolerance induction therapy in children of Arab descent with severe haemophilia A, high inhibitor titres and poor prognostic factors for immune tolerance induction treatment success. Haemophilia 2021; 28:65-72. [PMID: 34797008 PMCID: PMC9299496 DOI: 10.1111/hae.14456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Immune Tolerance Induction (ITI) is the first-choice therapy to eradicate Factor VIII (FVIII) neutralizing antibodies in patients with haemophilia A (HA). There is limited published data on ITI from East Mediterranean countries. AIM To assess the effectiveness of a low-dose ITI regimen to eradicate FVIII neutralizing antibodies in children with severe HA and high-titre inhibitors. METHODS A prospective, single-arm study was conducted in children with HA (FVIII < 1 IU/dl), high-titre inhibitors and poor prognostic factors for successful ITI. Patients were treated with ∼50 IU/kg plasma-derived FVIII containing von Willebrand factor (pdFVIII/VWF) concentrate (Koate-DVI, Grifols) three times a week. Time to achieve tolerance, total and partial success were analysed after ITI. Annual bleeding rate (ABR), number of target joints, FVIII recovery and school absence were compared before and after ITI. RESULTS Twenty patients with median (range) age of 6.2 (3-12) years and pre-ITI inhibitor titre of 36.5 (12-169) BU were enrolled. ITI lasted ≤12 months (early tolerization) in 45% of patients. Median follow-up was 12 months (3-22) and total response rate was 80% (60% total success; 20% partial success). Patients with two and three poor prognosis factors achieved overall success rate of 60% and 50%, respectively. ABR, target joints and school absence were reduced after ITI by 60%, 50% and 44.1%, respectively. In successful ITI tolerized patients, FVIII recovery was 90 (60-100)%. CONCLUSION A low-dose ITI therapy using a pdFVIII/VWF concentrate achieved at least partial tolerance in 80% of patients, and reduced annual bleeds in children with high inhibitor titres and at least one poor prognosis factor for ITI treatment success.
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Affiliation(s)
- Mohsen Elalfy
- Hemophilia Care Centre, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Islam Elghamry
- Hemophilia Care Centre, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Hoda Hassab
- Hemophilia Care Centre, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Omar Elalfy
- National Research Centre, Complementary Medicine, Cairo, Egypt
| | - Nevine Andrawes
- Hemophilia Care Centre, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Magdy El-Ekiaby
- Hematology Unit, Blood Transfusion Centre, Shabrawishi Hospital, Giza, Egypt
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15
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Assessing Plasmin Generation in Health and Disease. Int J Mol Sci 2021; 22:ijms22052758. [PMID: 33803235 PMCID: PMC7963172 DOI: 10.3390/ijms22052758] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/20/2021] [Accepted: 03/05/2021] [Indexed: 12/13/2022] Open
Abstract
Fibrinolysis is an important process in hemostasis responsible for dissolving the clot during wound healing. Plasmin is a central enzyme in this process via its capacity to cleave fibrin. The kinetics of plasmin generation (PG) and inhibition during fibrinolysis have been poorly understood until the recent development of assays to quantify these metrics. The assessment of plasmin kinetics allows for the identification of fibrinolytic dysfunction and better understanding of the relationships between abnormal fibrin dissolution and disease pathogenesis. Additionally, direct measurement of the inhibition of PG by antifibrinolytic medications, such as tranexamic acid, can be a useful tool to assess the risks and effectiveness of antifibrinolytic therapy in hemorrhagic diseases. This review provides an overview of available PG assays to directly measure the kinetics of plasmin formation and inhibition in human and mouse plasmas and focuses on their applications in defining the role of plasmin in diseases, including angioedema, hemophilia, rare bleeding disorders, COVID-19, or diet-induced obesity. Moreover, this review introduces the PG assay as a promising clinical and research method to monitor antifibrinolytic medications and screen for genetic or acquired fibrinolytic disorders.
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