Women and girls with inherited bleeding disorders: Focus on haemophilia carriers and heavy menstrual bleeding.

Raising awareness and improving recognition, accurate classification, and enhanced access to new treatments represent current key challenges for carriers of haemophilia. Women and girls carrying genes for haemophilia often experience significant bleeding and/or low factor levels. The bleeding associated with female haemophilia is frequently overlooked, has a weak correlation with factor levels, and manifests differently than in males, with heavy menstrual bleeding being a predominant symptom. Recent changes in terminology now allow the diagnosis of haemophilia in females with low factor levels and differentiate between symptomatic and asymptomatic carriers of the gene. Observations from real-world experiences and limited clinical trial data have highlighted the positive impact of various new haemophilia treatments for women and girls with clotting factor deficiencies. There is an urgent need for initiatives that increase their access to these treatments and encourage well-designed clinical trials focusing on female-specific outcomes. In women with inherited bleeding disorders, early recognition and optimal management of heavy menstrual bleeding are crucial. However, treatment options and guidance from high-quality clinical trials are currently insufficient. Menstrual health assessment should be a regular part of monitoring women and girls with inherited bleeding disorders throughout their lives, emphasizing the importance of gathering data to improve future management.

A novel method to quantify fibrin-fibrin and fibrin-α2-antiplasmin cross-links in thrombi formed from human trauma patient plasma.

BACKGROUND: The widespread use of the antifibrinolytic agent, tranexamic acid (TXA), interferes with the quantification of fibrinolysis by dynamic laboratory assays such as clot lysis, making it difficult to measure fibrinolysis in many trauma patients. At the final stage of coagulation, factor (F)XIIIa catalyzes the formation of fibrin-fibrin and fibrin-α2-antiplasmin (α2AP) cross-links, which increases clot mechanical strength and resistance to fibrinolysis. OBJECTIVES: Here, we developed a method to quantify fibrin-fibrin and fibrin-α2AP cross-links that avoids the challenges posed by TXA in determining fibrinolytic resistance in conventional assays. METHODS: Fibrinogen alpha (FGA) chain (FGA-FGA), fibrinogen gamma (FGG) chain (FGG-FGG), and FGA-α2AP cross-links were quantified using liquid chromatography-mass spectrometry (LC-MS) and parallel reaction monitoring in paired plasma samples from trauma patients prefibrinogen and postfibrinogen replacement. Differences in the abundance of cross-links in trauma patients receiving cryoprecipitate (cryo) or fibrinogen concentrate (Fg-C) were analyzed. RESULTS: The abundance of cross-links was significantly increased in trauma patients postcryo, but not Fg-C transfusion (P < .0001). The abundance of cross-links was positively correlated with the toughness of individual fibrin fibers, the peak thrombin concentration, and FXIII antigen (P < .05). CONCLUSION: We have developed a novel method that allows us to quantify fibrin cross-links in trauma patients who have received TXA, providing an indirect measure of fibrinolytic resistance. Using this novel approach, we have avoided the effect of TXA and shown that cryo increases fibrin-fibrin and fibrin-α2AP cross-linking when compared with Fg-C, highlighting the importance of FXIII in clot formation and stability in trauma patients.

Standardization of definition and management for bleeding disorder of unknown cause: communication from the SSC of the ISTH.

In many patients referred with significant bleeding phenotype, laboratory testing fails to define any hemostatic abnormalities. Clinical practice with respect to diagnosis and management of this patient cohort poses significant clinical challenges. We recommend that bleeding history in these patients should be objectively assessed using the International Society on Thrombosis and Haemostasis (ISTH) bleeding assessment tool. Patients with increased bleeding assessment tool scores should progress to hemostasis laboratory testing. To diagnose bleeding disorder of unknown cause (BDUC), normal complete blood count, prothrombin time, activated partial thromboplastin time, thrombin time, von Willebrand factor antigen, von Willebrand factor function, coagulation factors VIII, IX, and XI, and platelet light transmission aggregometry should be the minimum laboratory assessment. In some laboratories, additional specialized hemostasis testing may be performed to identify other rare causes of bleeding. We recommend that patients with a significant bleeding phenotype but normal laboratory investigations should be registered with a diagnosis of BDUC in preference to other terminology. Global hemostatic tests and markers of fibrinolysis demonstrate variable abnormalities, and their clinical significance remains uncertain. Targeted genomic sequencing examining candidate hemostatic genes has a low diagnostic yield. Underlying BDUC should be considered in patients with heavy menstrual bleeding since delays in diagnosis often extend to many years and negatively impact quality of life. Treatment options for BDUC patients include tranexamic acid, desmopressin, and platelet transfusions.

Contemporary management of major haemorrhage in critical care.

Haemorrhagic shock is frequent in critical care settings and responsible for a high mortality rate due to multiple organ dysfunction and coagulopathy. The management of critically ill patients with bleeding and shock is complex, and treatment of these patients must be rapid and definitive. The administration of large volumes of blood components leads to major physiological alterations which must be mitigated during and after bleeding. Early recognition of bleeding and coagulopathy, understanding the underlying pathophysiology related to specific disease states, and the development of individualised management protocols are important for optimal outcomes. This review describes the contemporary understanding of the pathophysiology of various types of coagulopathic bleeding; the diagnosis and management of critically ill bleeding patients, including major haemorrhage protocols and post-transfusion management; and finally highlights recent areas of opportunity to better understand optimal management strategies for managing bleeding in the intensive care unit (ICU).

A new population pharmacokinetic model for recombinant factor IX-Fc fusion concentrate including young children with haemophilia B.

AIMS: Recombinant factor IX Fc fusion protein (rFIX-Fc) is an extended half-life factor concentrate administered to haemophilia B patients. So far, a population pharmacokinetic (PK) model has only been published for patients aged ≥12 years. The aim was to externally evaluate the predictive performance of the published rFIX-Fc population PK model for patients of all ages and develop a model that describes rFIX-Fc PK using real-world data. METHODS: We collected prospective and retrospective data from patients with haemophilia B treated with rFIX-Fc and included in the OPTI-CLOT TARGET study (NTR7523) or United Kindom (UK)-EHL Outcomes Registry (NCT02938156). Predictive performance was assessed by comparing predicted with observed FIX activity levels. A new population PK model was constructed using nonlinear mixed-effects modelling. RESULTS: Real-world data were obtained from 37 patients (median age: 16 years, range 2-71) of whom 14 were aged <12 years. Observed FIX activity levels were significantly higher than levels predicted using the published model, with a median prediction error of -48.8%. The new model showed a lower median prediction error (3.4%) and better described rFIX-Fc PK, especially for children aged <12 years. In the new model, an increase in age was correlated with a decrease in clearance (P < .01). CONCLUSIONS: The published population PK model significantly underpredicted FIX activity levels. The new model better describes rFIX-Fc PK, especially for children aged <12 years. This study underlines the necessity to strive for representative population PK models, thereby avoiding extrapolation outside the studied population.

Early and Empirical High-Dose Cryoprecipitate for Hemorrhage After Traumatic Injury: The CRYOSTAT-2 Randomized Clinical Trial.

Importance: Critical bleeding is associated with a high mortality rate in patients with trauma. Hemorrhage is exacerbated by a complex derangement of coagulation, including an acute fibrinogen deficiency. Management is fibrinogen replacement with cryoprecipitate transfusions or fibrinogen concentrate, usually administered relatively late during hemorrhage. Objective: To assess whether survival could be improved by administering an early and empirical high dose of cryoprecipitate to all patients with trauma and bleeding that required activation of a major hemorrhage protocol. Design, Setting, and Participants: CRYOSTAT-2 was an interventional, randomized, open-label, parallel-group controlled, international, multicenter study. Patients were enrolled at 26 UK and US major trauma centers from August 2017 to November 2021. Eligible patients were injured adults requiring activation of the hospital's major hemorrhage protocol with evidence of active hemorrhage, systolic blood pressure less than 90 mm Hg at any time, and receiving at least 1 U of a blood component transfusion. Intervention: Patients were randomly assigned (in a 1:1 ratio) to receive standard care, which was the local major hemorrhage protocol (reviewed for guideline adherence), or cryoprecipitate, in which 3 pools of cryoprecipitate (6-g fibrinogen equivalent) were to be administered in addition to standard care within 90 minutes of randomization and 3 hours of injury. Main Outcomes and Measures: The primary outcome was all-cause mortality at 28 days in the intention-to-treat population. Results: Among 1604 eligible patients, 799 were randomized to the cryoprecipitate group and 805 to the standard care group. Missing primary outcome data occurred in 73 patients (principally due to withdrawal of consent) and 1531 (95%) were included in the primary analysis population. The median (IQR) age of participants was 39 (26-55) years, 1251 (79%) were men, median (IQR) Injury Severity Score was 29 (18-43), 36% had penetrating injury, and 33% had systolic blood pressure less than 90 mm Hg at hospital arrival. All-cause 28-day mortality in the intention-to-treat population was 26.1% in the standard care group vs 25.3% in the cryoprecipitate group (odds ratio, 0.96 [95% CI, 0.75-1.23]; P = .74). There was no difference in safety outcomes or incidence of thrombotic events in the standard care vs cryoprecipitate group (12.9% vs 12.7%). Conclusions and Relevance: Among patients with trauma and bleeding who required activation of a major hemorrhage protocol, the addition of early and empirical high-dose cryoprecipitate to standard care did not improve all cause 28-day mortality. Trial Registration: ClinicalTrials.gov Identifier: NCT04704869; ISRCTN Identifier: ISRCTN14998314.

Platelet factor XIII-A regulates platelet function and promotes clot retraction and stability.

Background: Factor XIII (FXIII) is an important proenzyme in the hemostatic system. The plasma-derived enzyme activated FXIII cross-links fibrin fibers within thrombi to increase their mechanical strength and cross-links fibrin to fibrinolytic inhibitors, specifically α2-antiplasmin, to increase resistance to fibrinolysis. We have previously shown that cellular FXIII (factor XIII-A [FXIII-A]), which is abundant in the platelet cytoplasm, is externalized onto the activated membrane and cross-links extracellular substrates. The contribution of cellular FXIII-A to platelet activation and platelet function has not been extensively studied. Objectives: This study aims to identify the role of platelet FXIII-A in platelet function. Methods: We used normal healthy platelets with a cell permeable FXIII inhibitor and platelets from FXIII-deficient patients as a FXIII-free platelet model in a range of platelet function and clotting tests. Results: Our data demonstrate that platelet FXIII-A enhances fibrinogen binding to the platelet surface upon agonist stimulation and improves the binding of platelets to fibrinogen and aggregation under flow in a whole-blood thrombus formation assay. In the absence of FXIII-A, platelets show reduced sensitivity to agonist stimulation, including decreased P-selectin exposure and fibrinogen binding. We show that FXIII-A is involved in platelet spreading where a lack of FXIII-A reduces the ability of platelets to fully spread on fibrinogen and collagen. Our data demonstrate that platelet FXIII-A is important for clot retraction where clots formed in its absence retracted to a lesser extent. Conclusion: Overall, this study shows that platelet FXIII-A functions during thrombus formation by aiding platelet activation and thrombus retraction in addition to its antifibrinolytic roles.

Experimental Models of Traumatic Injuries: Do They Capture the Coagulopathy and Underlying Endotheliopathy Induced by Human Trauma?

Trauma-induced coagulopathy (TIC) is a major cause of morbidity and mortality in patients with traumatic injury. It describes the spectrum of coagulation abnormalities that occur because of the trauma itself and the body's response to the trauma. These coagulation abnormalities range from hypocoagulability and hyperfibrinolysis, resulting in potentially fatal bleeding, in the early stages of trauma to hypercoagulability, leading to widespread clot formation, in the later stages. Pathological changes in the vascular endothelium and its regulation of haemostasis, a phenomenon known as the endotheliopathy of trauma (EoT), are thought to underlie TIC. Our understanding of EoT and its contribution to TIC remains in its infancy largely due to the scarcity of experimental research. This review discusses the mechanisms employed by the vascular endothelium to regulate haemostasis and their dysregulation following traumatic injury before providing an overview of the available experimental in vitro and in vivo models of trauma and their applicability for the study of the EoT and its contribution to TIC.

Acquired haemophilia A diagnosed during pregnancy.

Pregnancy-associated haemophilia A is an uncommon, acquired bleeding disorder which usually presents post-partum; very rarely it may present during pregnancy. No consensus guidelines exist on the management of this condition in pregnancy and very few cases have been reported in the literature. Here we describe the case of a woman presenting with acquired haemophilia A during pregnancy and outline the management of her bleeding disorder. We contrast her case with that of two other women, presenting to the same tertiary referral centre, with acquired haemophilia A presenting post-partum. These cases highlight the heterogeneous management of this condition and how it may be successfully managed in pregnancy.

A new global fibrinolysis capacity assay for the sensitive detection of hyperfibrinolysis and hypofibrinogenemia in trauma patients.

BACKGROUND: Conventional clotting tests are not expeditious enough to allow timely targeted interventions in trauma, and current point-of-care analyzers, such as rotational thromboelastometry (ROTEM), have limited sensitivity for hyperfibrinolysis and hypofibrinogenemia. OBJECTIVES: To evaluate the performance of a recently developed global fibrinolysis capacity (GFC) assay in identifying fibrinolysis and hypofibrinogenemia in trauma patients. METHODS: Exploratory analysis of a prospective cohort of adult trauma patients admitted to a single UK major trauma center and of commercially available healthy donor samples was performed. Lysis time (LT) was measured in plasma according to the GFC manufacturer's protocol, and a novel fibrinogen-related parameter (percentage reduction in GFC optical density from baseline at 1 minute) was derived from the GFC curve. Hyperfibrinolysis was defined as a tissue factor-activated ROTEM maximum lysis of >15% or LT of ≤30 minutes. RESULTS: Compared to healthy donors (n = 19), non-tranexamic acid-treated trauma patients (n = 82) showed shortened LT, indicative of hyperfibrinolysis (29 minutes [16-35] vs 43 minutes [40-47]; p < .001). Of the 63 patients without overt ROTEM-hyperfibrinolysis, 31 (49%) had LT of ≤30 minutes, with 26% (8 of 31) of them requiring major transfusions. LT showed increased accuracy compared to maximum lysis in predicting 28-day mortality (area under the receiver operating characteristic curve, 0.96 [0.92-1.00] vs 0.65 [0.49-0.81]; p = .001). Percentage reduction in GFC optical density from baseline at 1 minute showed comparable specificity (76% vs 79%) to ROTEM clot amplitude at 5 minutes from tissue factor-activated ROTEM with cytochalasin D in detecting hypofibrinogenemia but correctly reclassified >50% of the patients with false negative results, leading to higher sensitivity (90% vs 77%). CONCLUSION: Severe trauma patients are characterized by a hyperfibrinolytic profile upon admission to the emergency department. The GFC assay is more sensitive than ROTEM in capturing hyperfibrinolysis and hypofibrinogenemia but requires further development and automation.

The European guideline on management of major bleeding and coagulopathy following trauma: sixth edition.

BACKGROUND: Severe trauma represents a major global public health burden and the management of post-traumatic bleeding continues to challenge healthcare systems around the world. Post-traumatic bleeding and associated traumatic coagulopathy remain leading causes of potentially preventable multiorgan failure and death if not diagnosed and managed in an appropriate and timely manner. This sixth edition of the European guideline on the management of major bleeding and coagulopathy following traumatic injury aims to advise clinicians who care for the bleeding trauma patient during the initial diagnostic and therapeutic phases of patient management. METHODS: The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma included representatives from six European professional societies and convened to assess and update the previous version of this guideline using a structured, evidence-based consensus approach. Structured literature searches covered the period since the last edition of the guideline, but considered evidence cited previously. The format of this edition has been adjusted to reflect the trend towards concise guideline documents that cite only the highest-quality studies and most relevant literature rather than attempting to provide a comprehensive literature review to accompany each recommendation. RESULTS: This guideline comprises 39 clinical practice recommendations that follow an approximate temporal path for management of the bleeding trauma patient, with recommendations grouped behind key decision points. While approximately one-third of patients who have experienced severe trauma arrive in hospital in a coagulopathic state, a systematic diagnostic and therapeutic approach has been shown to reduce the number of preventable deaths attributable to traumatic injury. CONCLUSION: A multidisciplinary approach and adherence to evidence-based guidelines are pillars of best practice in the management of severely injured trauma patients. Further improvement in outcomes will be achieved by optimising and standardising trauma care in line with the available evidence across Europe and beyond.

Traumatic coagulopathy in the older patient: analysis of coagulation profiles from the Activation of Coagulation and Inflammation in Trauma-2 (ACIT-2) observational, multicenter study.

BACKGROUND: Most studies describing traumatic coagulopathy have used data from patient cohorts with an average age of between 35 and 45 years. The last 10 years has seen a steep increase in the number of patients admitted with significant injury and bleeding who are older than the age of 65 years. Many coagulation protein levels alter significantly with normal aging, and it is possible that traumatic coagulopathy has a different signature with age. OBJECTIVES: The aim of this study was to report the coagulation profiles, including standard and extended laboratory, as well as viscoelastic hemostatic assays, stratified according to age to explore age-related differences in hemostatic capability. METHODS: In total, 1576 patients were analyzed from 6 European level 1 trauma centers. RESULTS: As age increased, there was evidence of higher fibrinogen, greater thrombin generation, greater clotting factor consumption, and greater activation of fibrinolysis. Despite this, shock and severe injury led to the same pattern of changes within age groups: lower procoagulant factors (including fibrinogen), increased fibrinolysis, and higher levels of activated protein C. Thromboelastography and rotational thromboelastometry tests detected traumatic coagulopathy with prolongation of R/clotting time and reductions in clot amplitudes in each age cohort. Advancing age strongly correlated with higher fibrinogen levels and greater fibrinolysis. CONCLUSION: Age-related coagulation changes are evident in injured patients. Broadly, similar patterns of coagulation abnormalities are seen across age groups following severe injury/shock, but thresholds for single clotting factors differ. Age-related differences may need to be considered when clinical treatments (eg, transfusion therapy) are indicated.

The CRYOSTAT2 trial: The rationale and study protocol for a multi-Centre, randomised, controlled trial evaluating the effects of early high-dose cryoprecipitate in adult patients with major trauma haemorrhage requiring major haemorrhage protocol activation.

OBJECTIVES: To describe the protocol for a multinational randomised, parallel, superiority trial, in which patients were randomised to receive early high-dose cryoprecipitate in addition to standard major haemorrhage protocol (MHP), or Standard MHP alone. BACKGROUND: Blood transfusion support for trauma-related major bleeding includes red cells, plasma and platelets. The role of concentrated sources of fibrinogen is less clear and has not been evaluated in large clinical trials. Fibrinogen is a key pro-coagulant factor that is essential for stable clot formation. A pilot trial had demonstrated that it was feasible to deliver cryoprecipitate as a source of fibrinogen within 90 min of admission. METHODS: Randomisation was via opaque sealed envelopes held securely in participating Emergency Departments or transfusion laboratories. Early cryoprecipitate, provided as 3 pools (equivalent to 15 single units of cryoprecipitate or 6 g fibrinogen supplementation), was transfused as rapidly as possible, and started within 90 min of admission. Participants in both arms received standard treatment defined in the receiving hospital MHP. The primary outcome measure was all-cause mortality at 28 days. Symptomatic thrombotic events including venous thromboembolism and arterial thrombotic events (myocardial infarction, stroke) were collected from randomisation up to day 28 or discharge from hospital. EQ5D-5Land Glasgow Outcome Score were completed at discharge and 6 months. All analyses will be performed on an intention to treat basis, with per protocol sensitivity analysis. RESULTS: The trial opened for recruitment in June 2017 and the final patient completed follow-up in May 2022. DISCUSSION: This trial will provide firmer evidence to evaluate the effectiveness and cost-effectiveness of early high-dose cryoprecipitate alongside the standard MHP in major traumatic haemorrhage.

Cryoprecipitate transfusion in trauma patients attenuates hyperfibrinolysis and restores normal clot structure and stability: Results from a laboratory sub-study of the FEISTY trial.

BACKGROUND: Fibrinogen is the first coagulation protein to reach critical levels during traumatic haemorrhage. This laboratory study compares paired plasma samples pre- and post-fibrinogen replacement from the Fibrinogen Early In Severe Trauma studY (FEISTY; NCT02745041). FEISTY is the first randomised controlled trial to compare the time to administration of cryoprecipitate (cryo) and fibrinogen concentrate (Fg-C; Riastap) in trauma patients. This study will determine differences in clot strength and fibrinolytic stability within individuals and between treatment arms. METHODS: Clot lysis, plasmin generation, atomic force microscopy and confocal microscopy were utilised to investigate clot strength and structure in FEISTY patient plasma. RESULTS: Fibrinogen concentration was significantly increased post-transfusion in both groups. The rate of plasmin generation was reduced 1.5-fold post-transfusion of cryo but remained unchanged with Fg-C transfusion. Plasminogen activator inhibitor 1 activity and antigen levels and Factor XIII antigen were increased post-treatment with cryo, but not Fg-C. Confocal microscopy analysis of fibrin clots revealed that cryo transfusion restored fibrin structure similar to those observed in control clots. In contrast, clots remained porous with stunted fibres after infusion with Fg-C. Cryo but not Fg-C treatment increased individual fibre toughness and stiffness. CONCLUSIONS: In summary, our data indicate that cryo transfusion restores key fibrinolytic regulators and limits plasmin generation to form stronger clots in an ex vivo laboratory study. This is the first study to investigate differences in clot stability and structure between cryo and Fg-C and demonstrates that the additional factors in cryo allow formation of a stronger and more stable clot.

Gynaecological management of women with inherited bleeding disorders. A UK Haemophilia Centres Doctors' Organisation Guideline.

Women with inherited bleeding disorders (IBDs) may present to healthcare professionals in a variety of ways and commonly will be encountered by either haematology or gynaecology services. Heavy menstrual bleeding is very often the first manifestation of an IBD. There is a wide variation in severity of bleeding for women with IBD and diagnosis and subsequent management of their condition requires multidisciplinary specialised care which is tailored to the individual and includes excellent cross-specialty communication between gynaecology and haematology teams. This guideline is intended for both haematologists and gynaecologists who are involved in the diagnosis and management of women with bleeding disorders. It sets out recommendations about how to investigate heavy menstrual bleeding (HMB), the commonest presentation for women with IBD to hospital services, to guide physicians about how to diagnose an IBD and covers the management of women with known IBD and HMB. The second section sets out recommendations for patients known to have IBD and covers management of patients with IBD in the setting of gynaecological surgery and management for all other non-surgical gynaecological situations.

Should all patients receive extended thromboprophylaxis after resection of primary lung cancer?

OBJECTIVE: The optimal duration of thromboprophylaxis in patients undergoing resection of primary lung cancer is not known. We investigated the incidence of pulmonary emboli and venous thromboembolism in patients undergoing early-stage lung cancer resection and the impact of change from short duration to extended thromboprophylaxis. METHODS: We reviewed the outcomes of consecutive patients who underwent resection of early-stage primary lung cancer following a change in protocol from inpatient-only to extended thromboprophylaxis to 28 days. Propensity-score matching of control (routine inpatient pharmacologic thromboprophylaxis) and treatment group (extended pharmacologic thromboprophylaxis) was performed. Adjustment for covariates based on the Caprini risk assessment model was undertaken. Thromboembolic outcomes were compared between the 2 groups. RESULTS: Seven hundred fifty consecutive patients underwent resection of primary lung cancer at Oxford University Hospitals NHS Foundation Trust between January 2013 and December 2018. Six hundred patients were included for analysis and propensity-score matching resulted in 253 matched pairs. Extended prophylaxis was associated with a significant reduction in pulmonary emboli (10 of 253 patients [4%] vs 1 of 253 patients [0.4%], P = .01). One patient (0.4%) developed a bleeding complication within the treatment cohort. Multivariable logistic regression model demonstrated that extended thromboprophylaxis was independently associated with a reduction in postoperative pulmonary emboli. CONCLUSIONS: Patients undergoing lung cancer resection surgery are at moderate-to-high risk of postoperative thromboembolic disease. Extended dalteparin for 28 days is safe and is associated with reduced incidence of pulmonary embolus in patients undergoing resection of early-stage primary lung cancer.