Activated Coagulation Factor Research Articles

A case report of Acquired Prothrombin Complex Deficiency in Infant

Introduction: Acquired Prothrombin Complex Deficiency (APCD) is a disorder characterized by spontaneous bleeding caused by decreased activity of vitamin K-dependent coagulation factors (factors II, VII, IX, and X), despite normal fibrinogen and platelet counts. It can occur in newborns as young as 6 months old. This disease is linked to drug use during pregnancy, a lack of vitamin K-containing foods, and other secondary diseases. The manifestations of this disease vary, ranging from skin organs to gastrointestinal organs to the brain, with high morbidity and mortality rates. The aim of this case report is to describe an infant with diagnose of APCD and their management. Case Presentation: A 55-day-old patient had been in a coma and had been unconscious for three days before being admitted to the hospital. The patient vomited, developed a fever, and had a seizure. The laboratory examination showed that haemoglobin levels was 5.6g/dl, prothrombin time (PT) was 21 seconds, activated partial thromboplastin time (APTT) was extended by 54 seconds, and platelet showed abnormal 524 x 10^3µL in the result. The PT and APTT results indicated APCD, but there is an abnormality in platelets, which should be normal in APCD patient. Conclusion: This is a case reported of Acquired Prothrombin Complex Deficiency (APCD) based on laboratory and CT-Scan examination.

Comparison of ketamine/xylazine and isoflurane anesthesia on the establishment of mouse middle cerebral artery occlusion model.

The middle cerebral artery occlusion model (MCAO) is one of the most common stroke models in neuroscience research. The establishment of the mouse MCAO model in terms of animal survival depends on anesthesia, which is an important part of the entire surgical process. The 7-day survival rate of the MCAO model under isoflurane (ISO) anesthesia (35%) was lower than ketamine/xylazine (KX) anesthesia (70%), which demonstrated that the success rate of the MCAO model under KX anesthesia would be significantly higher than that under ISO anesthesia. As confirmed by TTC staining and MRI, the cerebral infarction area of mice successfully modeled under ISO anesthesia was significantly smaller than that of KX anesthesia. The diameter of cerebral blood vessels under ISO anesthesia was significantly larger than that under KX, and the blood perfusion volume was also significantly increased in the same area. ISO has proven to delay the coagulation time and affect the activation of coagulation factors. ISO anesthesia may cause bleeding, vasodilation, respiratory depression, and other phenomena that affect the success rate and death of diseased animal models. In conclusion, compared with ISO anesthesia, KX anesthesia is a safer and more suitable method for the establishment of a mouse MCAO model. The data will inform safer and more detailed anesthesia recommendations forthe establishment of animal models of vascular-related major injury diseases.

How to translate and implement the current science of gene therapy into haemophilia care?

Gene-based therapy opens an entirely new paradigm in managing people with haemophilia (PWH), offering them the possibility of a functional cure by enabling continuous expression of factor VIII (FVIII) or factor IX (FIX) after transfer of a functional gene designed to replace the PWH's own defective gene. In recent years, significant advances in gene therapy have been made, resulting in clotting factor activity attaining near-normal levels, as reflected by 'zero bleeding rates' in previously severely inflicted patients following a single administration of adeno-associated viral (AAV) vectors. While this new approach represents a major advancement, there are still several issues that must be resolved before applying this technology in clinical practice. First, awareness, communication, and education about the therapeutic potential and modalities of gene therapy must be further strengthened. To this end, objective, unbiased, transparent, and regularly updated information must be shared, in an appropriate way and understandable language with the support of patients' organizations. Second, healthcare providers should adopt a patient-centred approach, as the 'one size fits all' approach is inappropriate when considering gene therapy. Instead, a holistic patient view taking into account their physical and mental dimensions, along with unexpressed expectations and preferences, is mandatory. Third, the consent procedure must be improved, ensuring that patients' interests are maximally protected. Finally, gene therapy is likely to be first delivered in a few centres, with the highest expertise and experience in this domain. Thus, patients should be managed based on a hub-and-spoke model, taking into account that the key to gene therapy's success lies in an optimal communication and collaboration both within and between haemophilia centres sharing their experiences in the frame of international registries. This review describes recent progress and explains outstanding hurdles that must be tackled to ease the implementation of this paradigm-changing new therapy.

Effect of Human Recombinant Activated Coagulation Factor VII (rFVIIa) on Total Bleeding Volume and Coagulation Function of Patients

Effect of Human Recombinant Activated Coagulation Factor VII (rFVIIa) on Total Bleeding Volume and Coagulation Function of Patients

Low Value of Activated Coagulation Factor VII in Young Primary Spontaneous Pneumothorax

Low Value of Activated Coagulation Factor VII in Young Primary Spontaneous Pneumothorax

Effect of Edoxaban, F-Xa-Directed Oral Anticoagulant on Spontaneous Thrombolytic Activity in Apoe-/- and Ldlr-/- Double Knockout Mice

The details of thrombolytic activity in occlusive disease associated with atherosclerotic lesions are not clear. This study investigated the novel effects of activated coagulation factor X (F-Xa)-directed oral anticoagulant (DOAC) edoxaban on in vivo thrombolytic activity and atherosclerosis progression.

Severe high-molecular-weight kininogen deficiency: clinical characteristics, deficiency–causing KNG1 variants, and estimated prevalence

BackgroundSevere high-molecular-weight kininogen (HK) deficiency is a poorly studied autosomal recessive contact system defect caused by pathogenic, biallelic KNG1 variants. AimWe performed the first comprehensive analysis of diagnostic, clinical, genetic, and epidemiological aspects of HK deficiency. MethodsWe collected clinical information and blood samples from a newly detected HK-deficient individual and from published cases identified by a systematic literature review. Activity and antigen levels of coagulation factors were determined. Genetic analyses of KNG1 and KLKB1 were performed by Sanger sequencing. The frequency of HK deficiency was estimated considering truncating KNG1 variants from GnomAD. ResultsWe identified 48 cases of severe HK deficiency (41 families), of these 47 have been previously published (n = 19 from gray literature). We genotyped 3 cases and critically appraised 10 studies with genetic data. Ten HK deficiency–causing variants (one new) were identified. All of them were truncating mutations, whereas the only known HK amino acid substitution with a relevant phenotype instead causes hereditary angioedema. Conservative estimates suggest an overall prevalence of severe HK deficiency of approximately one case per 8 million population, slightly higher in Africans. Individuals with HK deficiency appeared asymptomatic and had decreased levels of prekallikrein and factor XI, which could lead to misdiagnosis. ConclusionHK deficiency is a rare condition with only few known pathogenic variants. It has an apparently good prognosis but is prone to misdiagnosis. Our understanding of its clinical implications is still limited, and an international prekallikrein and HK deficiency registry is being established to fill this knowledge gap.

Little discrepancy between one-stage and chromogenic factor VIII (FVIII)/IX assays in a large international cohort of persons with nonsevere hemophilia A and B

BackgroundAccurate measurements of coagulation factor activity form an essential part of hemophilia management and are performed by the one-stage or chromogenic assay. Current literature suggests that approximately one-third of persons with nonsevere hemophilia A exhibit assay discrepancy, albeit with a high variability between studies. Such data are scarce in nonsevere hemophilia B. ObjectivesTo investigate the extent of factor VIII/IX one-stage and chromogenic assay discrepancy in moderate and mild hemophilia A and B. MethodsPersons with previously diagnosed nonsevere hemophilia A and B with a factor level of 2 to 35 IU/dL were included from the international DYNAMO cohort study. Central measurements of the factor VIII and IX activity levels were performed by the one-stage and chromogenic assay. Relative and absolute discrepancy definitions were used, with the International Society on Thrombosis and Haemostasis-Scientific and Standardization Committee proposed ratio of >2.0 or <0.5 being the primary outcome. Discrepancy was also evaluated in a subgroup of 13 persons with mutations previously associated with discrepancy (≥3 cases reported in literature). ResultsA total of 220 persons were included, of whom 3 (1%) showed assay discrepancy: 2/175 hemophilia A and 1/45 hemophilia B. Six persons (3%) exhibited an absolute difference >10 IU/dL between the assay results. In addition, with more lenient definitions, over 90% of participants (n = 197) had no discrepant results. Only 1 out of 13 persons with a mutation previously associated with discrepancy had significant assay discrepancy. ConclusionLittle assay discrepancy was observed despite the presence of mutations previously associated with discrepancy, suggesting that the presence and magnitude of assay discrepancy are largely determined by laboratory variables.

Postpartum Acquired Hemophilia (PAH) – A Rare Entity

Objective: Acquired Hemophilia A (AHA) is a rare autoimmune disease that can result in life threatening bleeding. Formation of auto-antibodies (inhibitors) against coagulation factor VIII develops the hemorrhagic syndrome that may appear at any age; however, prevalence of AHA is chiefly observed in post-partum and elderly persons. Idiopathic acquired hemophilia is commonest type of acquired hemophilia whereas it is also associated with autoimmune disease, malignant neoplasm, medication and vaccinations. Post-partum acquired hemophilia (PAH) may develop due to development of antibodies against fetal FVIII. In this case report, 36-year-old Asian woman presented with complain of bruises from 2 months. There was history of cesarean section four months ago. Family history, past medical and drug history were not significant. As there was no active bleeding, patient was started an oral prednisolone along with azathioprine and was counseled regarding disease and precautions. Patient presented after 2 weeks with severe PV bleed, anemia secondary to self-induced medicine abortion. For this she receives pack cells and cryoprecipitate. Steroids and azathioprine were continued and patient was discharged in stable condition. Her ultrasound pelvis however showed small fibroids. Patient went back to her village where she again develops severe PV bleed and for that she underwent hysterectomy. Patient presented in our hospital with severe operative site bleeding, pain and anemia. She was managed with Packed Red Blood (PRBCs), Fresh Frozen Plasma (FFP), Recombinant Activated Clotting Factor VII (rFVIIa), prednisolone IV and azathioprine PO. Her Activated Partial Thromboplastin, Hemoglobin were continuously monitored. After a week bleeding was stopped but Activated Partial Thromboplastin Time (APTT) was still prolonged so we tapered rFVIIa dose and advice two sessions of plasmapheresis. APTT, hemoglobin levels, inhibitor titer, High-Sensitivity C – reactive protein (hs-CRP) levels were improved. Patient was discharged in a stable condition and was advised to continue medication at home with supportive care and wound dressing.

Thrombophilia and outcomes of venous thromboembolism in older patients

BackgroundLimited data exist on thrombophilic risk factors and clinical outcomes in the elderly with venous thromboembolism (VTE). ObjectivesTo describe the prevalence of laboratory thrombophilic risk factors and their association with VTE recurrence or death in a cohort of elderly people with VTE. MethodsIn 240 patients aged ≥65 years with acute VTE without active cancer or an indication for extended anticoagulation, we performed laboratory thrombophilia testing 1 year after the index VTE. Recurrence or death was assessed during the 2-year follow-up. ResultsA total of 78% of patients had ≥1 laboratory thrombophilic risk factor(s). Elevated levels of von Willebrand factor, homocysteine, coagulant activity of factor VIII (FVIII:C), fibrinogen, FIX:C, and low antithrombin activity were the most prevalent risk factors (43%, 30%, 15%, 14%, 13%, and 11%, respectively). Additionally, 16.2% of patients experienced VTE recurrence and 5.8% of patients died. Patients with a von Willebrand factor of >182%, FVIII:C level >200%, homocysteine level >15μmol/L, or lupus anticoagulant had a significantly higher rate of recurrence than those without these risk factors (15.0 vs. 6.1 [P = .006], 23.5 vs. 8.2 [P = .01], 17.0 vs. 6.8 [P = .006], and 89.5 vs. 9.2 [P = .02] events per 100 patient-years, respectively). Furthermore, patients with a high fibrinogen level or hyperhomocysteinemia with a homocysteine level ≥30 μmol/L had significantly higher mortality than patients with normal levels (18.5 vs. 2.8 [P = .049] and 13.6 vs. 2 [P = .002] deaths per 100 patient-years, respectively). After adjustments for relevant confounders, these associations remained unchanged. ConclusionLaboratory thrombophilic risk factors are common in elderly people with VTE and allow for the identification of a population at the risk of worse clinical outcomes.

FREQUÊNCIA DA OCORRÊNCIA DE EVENTOS TROMBOEMBÓLICOS NA COVID-19: REVISÃO INTEGRATIVA

The pandemic caused by the SARS-CoV-2 virus has affected the health services and day-to-day lives of billions of people around the world. COVID-19 is a lung infection that causes mild to severe symptoms. It is known that the hemostatic disorder resulting from this infection produces an immune response that triggers the activation of coagulation factors and thrombin release, communicating the pathways of humoral and cellular amplification causing thromboinflammation. Thromboembolic events represent an important portion of potentially fatal consequences in patients who have evolved to severe form and secondary complications, especially in survivors with post-covid syndrome. This article is an integrative revisional study of the literature that analyzes the events already reported. PubMed and Scielo databases were used to search for the main thromboembolic events resulting from this infection.

The role of the fibrinolytic system laboratory markers in the assessment of the cerebral small vessel disease severity

Background: Small vessel disease (SVD) is a common brain disease causing about 40% of all dementias and about 25% of ischemic strokes, which makes important the study of its pathophysiology and the search for its biomarkers. A number of studies have shown a significant role of endothelial dysfunction and nonspecific inflammation, as well as of some individual parameters of hemostasis disorders in the development of SVD.&#x0D; Aim: To identify the role of the laboratory markers of fibrinolytic system in the assessment of the severity of white matter lesions in patients with SVD.&#x0D; Materials and methods: This single center cross-sectional non-controlled observational study included 117 patients with dyscirculatory encephalopathy (chronic brain ischemia), with a mean ( SD) age of 57.7 11.5 years. Laboratory tests of the fibrinolytic system, endothelial dysfunction, markers of inflammation and for an integral assessment of plasma hemostasis were performed in all patients, including XIIa-dependent fibrinolysis, levels of plasminogen, alpha2-antiplasmin, plasminogen activator inhibitor 1 (PAI-1), fibrinogen, von Willebrand factor (vWF) and activity of blood coagulation factor VIII (FVIII), highly sensitive C-reactive protein and parameters of the thrombodynamics assay. In all the patients, brain magnetic resonance imaging was performed with the assessment of the white matter lesions by the Fazecas scale.&#x0D; Results: Depending on the identified neuroimaging SVD markers (assessed with the Fazecas scale), the patients were divided into the SVD group (n = 54) and no-SVD group (n = 63). Those with SVD were older than those without (65 9 vs 51 10 years; p 0.001), had higher prevalence of arterial hypertension (p 0.001), diabetes mellitus (p = 0.029) and past thrombotic events (p 0.001). The SVD patients, compared to those without SVD, had a higher time of XIIa-dependent fibrinolysis (7.6 2.9 vs 6.5 1.7 min, p = 0.032), higher alpha2-antiplasmin levels (111 [95117] vs 105 [95111]%, p = 0.016) and higher clot density (D) (22789 [2056726411] vs 20627 [1832422650] U, p 0.001), although the parameters were within the reference ranges. As far as the thrombodynamics is concerned, the SVD group had higher values for all test parameters, as well as higher levels of the inflammation and endothelial dysfunction markers. Increased time of XIIa-dependent fibrinolysis was associated with higher probability of periventricular and subcortical leukoareosis grade 2 by the Fazecas scale (odds ratio 1.31 [1.071.60], p = 0.009), including an increase in the size and number of gliosis areas. Higher plasminogen levels were associated with a lower probability of leukoareosis by the Fazecas scale (odds ratio 0.97 [0.950.98], p 0.001).&#x0D; Conclusion: The severity of fibrinolytic and hemostatic abnormalities correlates with the severity of brain SVD, thus forming the hypofibrinolytic and prothrombotic status of the patients with this disorder.

Biological activity of a new recombinant human coagulation factor VIII and its efficacy in a small animal model

Deficiency in human coagulation factor VIII (FVIII) causes hemophilia A (HA). Patients with HA may suffer from spontaneous bleeding, which can be life-threatening. Recombinant FVIII (rFVIII) is an established treatment and prevention agent for bleeding in patients with HA. Human plasma-derived FVIII (pdFVIII), commonly used in clinical practice, is relatively difficult to prepare. In this study, we developed a novel B-domain-deleted rFVIII, produced and formulated without the use of animal or human serum-derived components. rFVIII promoted the generation of activated factor X and downstream thrombin, and, similar to that of other available FVIII preparations, its activity was inhibited by FVIII inhibitors. In addition, rFVIII has ideal binding affinity to human von Willebrand factor. Activated FVIII (FVIIIa) could be degraded by activated protein C and lose its procoagulant activity. In vitro, commercially available recombinant FVIII (Xyntha) and pdFVIII were used as controls, and there were no statistical differences between rFVIII and commercial FVIII preparations, which demonstrates the satisfactory efficacy and potency of rFVIII. In vivo, HA mice showed that infusion of rFVIII rapidly corrected activated partial thromboplastin time, similar to Xyntha. Moreover, different batches of rFVIII were comparable. Overall, our results demonstrate the potential of rFVIII as an effective strategy for the treatment of FVIII deficiency.

Perioperative Management of Dental Surgery Patients Chronically Taking Antithrombotic Medications.

The development of medicine is based not only on the introduction of new methods of treatment, but also on the use of increasingly effective drugs, including antithrombotic drugs. Drugs that inhibit the activity of platelets (antiplatelet and anti-aggregating drugs) and pharmaceuticals that inhibit the activity of plasma coagulation factors (anticoagulants) are used in antithrombotic therapy. In our daily practice we encounter patients who take chronic antiplatelet or anticoagulant drugs. However, more and more often we are dealing with patients who are treated with two antiplatelet drugs, an antiplatelet and an anticoagulant or even undergoing triple antithrombotic therapy. When preparing the patient for invasive craniofacial procedures, it should be assessed whether the temporary discontinuation of antithrombotic treatment due to the fear of excessive perioperative bleeding is justified and will not result in life-threatening thromboembolic complications. The authors discuss in detail the medications used in modern antithrombotic treatment and present a perioperative management procedure with a patient who takes l4 z of these medications chronically.

Beyond uterine atony: characterizing postpartum hemorrhage coagulopathy

Postpartum hemorrhage is a leading cause of morbidity and mortality worldwide, yet the associated early coagulopathy is not well defined. We hypothesized that women who develop postpartum hemorrhage have a distinct derangement of thrombin generation and coagulation factors compared with postpartum women without postpartum hemorrhage. This prospective study of pregnant patients with postpartum hemorrhage was completed at a single urban hospital. Blood was drawn on postpartum hemorrhage diagnosis and 2 and 4 hours later. Assays of patients with postpartum hemorrhage included thrombelastography, whole blood thrombin generation, coagulation factor activity, tissue factor levels and activity, and tissue factor pathway inhibitor levels, which were compared with that of patients without postpartum hemorrhage. A total of 81 patients were included in this study. Of those patients, 66 had postpartum hemorrhage, and 15 served as controls. Compared with patients without PPH, patients with postpartum hemorrhage had lower fibrinogen levels (469.0 mg/dL vs 411.0 mg/dL; P=.02), increased tissue plasminogen activator resistance (fibrinolysis 30 minutes after maximal clot strength: 8.7% vs 4.2%; P=.02), decreased peak thrombin concentration (150.2 nM vs 40.7 nM; P=.01), and decreased maximal rate of thrombin generation (60.1 nM/minute vs 2.8 nM/minute; P=.02). Furthermore, compared with patients without postpartum hemorrhage, patients with postpartum hemorrhage had decreased tissue factor levels (444.3 pg/mL vs 267.1 pg/mL; P=.02) and increased tissue factor pathway inhibitor levels (0.6 U/mL vs 0.8 U/mL; P=.04), with decreased tissue factor pathway inhibitor ratios (624 vs 299; P=.01). PPH is not only an issue of uterine tone and mechanical bleeding but also a distinct coagulopathy that is characterized by decreased fibrinogen level, clot breakdown resistance, and markedly low thrombin generation. This pathology seemed to be driven by low tissue factor and high tissue factor pathway inhibitor levels.

Inhibition of platelet-surface-bound proteins during coagulation under flow I: TFPI

Blood coagulation is a self-repair process regulated by activated platelet surfaces, clotting factors, and inhibitors. Tissue factor pathway inhibitor (TFPI) is one such inhibitor, well known for its inhibitory action on the active enzyme complex comprising tissue factor (TF) and activated clotting factor VII. This complex forms when TF embedded in the blood vessel wall is exposed by injury and initiates coagulation. A different role for TFPI, independent of TF:VIIa, has recently been discovered whereby TFPI binds a partially cleaved form of clotting factor V (FV-h) and impedes thrombin generation on activated platelet surfaces. We hypothesized that this TF-independent inhibitory mechanism on platelet surfaces would be a more effective platform for TFPI than the TF-dependent one. We examined the effects of this mechanism on thrombin generation by including the relevant biochemical reactions into our previously validated mathematical model. Additionally, we included the ability of TFPI to bind directly to and inhibit platelet-bound FXa. The new model was sensitive to TFPI levels and, under some conditions, TFPI could completely shut down thrombin generation. This sensitivity was due entirely to the surface-mediated inhibitory reactions. The addition of the new TFPI reactions increased the threshold level of TF needed to elicit a strong thrombin response under flow, but the concentration of thrombin achieved, if there was a response, was unchanged. Interestingly, we found that direct binding of TFPI to platelet-bound FXa had a greater anticoagulant effect than did TFPI binding to FV-h alone, but that the greatest effects occurred if both reactions were at play. The model includes activated platelets’ release of FV species, and we explored the impact of varying the FV/FV-h composition of the releasate. We found that reducing the zymogen FV fraction of this pool, and thus increasing the fraction that is FV-h, led to acceleration of thrombin generation.

Effect of allogeneic blood transfusion on neutrophil functional activity and lymphocyte cytotoxicity in recipient rabbits

The relevance of this paper is that transfusion of allogeneic blood to recipient animals is always associated with immunological risks. In this regard, the purpose of this study was to assess the state of phagocytic activity of blood neutrophils by indicators of phagocytic index, phagocytic number, and oxygen-dependent bactericidal activity, as well as to establish changes in antibody-dependent cytotoxic activity of lymphocytes in recipient rabbits during allogeneic whole blood transfusion. Modelling of blood transfusions was performed on five clinically healthy rabbits by intravenous administration of whole blood at the rate of 5.5 ml/kg of body weight. Blood samples were taken from animals on Days 3, 7, and 23 after blood transfusion. Neutrophil populations were obtained from blood samples by centrifugation on a double density gradient of 1.077 and 1.093 Ficoll-Verografin. The absorption activity of phagocytes was determined in a microscopic test. To investigate the oxygen-dependent bactericidal activity of neutrophils, a spontaneous test with nitroblue tetrazolium was performed. Antibody-dependent cytotoxic activity of lymphocytes was investigated by colorimetric method. It was found that after the transfusion of whole blood, the phagocytic activity of neutrophils increases with a simultaneous decrease in their absorption capacity. On Days 3 and 7, the results of the spontaneous test with nitroblue tetrazolium decreased. This indicates inactivation of the oxygen-dependent bactericidal activity of neutrophil granulocytes during the first phase of post-transfusion immunological reactions. On Day 23, there was an increase in the values of the indicators of the spontaneous test with nitroblue tetrazolium, which indicates the activation of the bactericidal properties of phagocytes. It was found that on Day 3, the antibody-dependent cytotoxic activity of lymphocytes significantly decreased relative to the initial state, and on Days 7 and 23, it increased. An increase in the antibody-dependent cytotoxic activity of lymphocytes should be associated with the active synthesis of antibodies of the late phase of the immune response. Consequently, transfusion of allogeneic blood causes an immune response in recipient rabbits, without causing immediate and long-term transfusion reactions (changes in heart rate, respiratory rate, body temperature). The obtained results are of practical value both for scientists and practising doctors who use transfusion of whole blood and its components to animals with acute anaemia, impaired functional activity of blood coagulation factors, parasitic, and oncological diseases

Novel Gamma-Glutamyl Carboxylase Mutation Causing Hemorrhagic and Non-Hemorrhagic VKCFD1 Phenotypes

Background: Vitamin K clotting factor deficiency (VKCFD) types 1 and 2 are very rare autosomal recessive disorders associated with reduced clotting factors activities for all vitamin K dependent clotting factors. Less than 30 cases are reported with defects in GGCX (gamma-glutamyl carboxylase) leading to VKCFD Type 1 (VKCFD1) or VKORC1 (vitamin K epoxide reductase complex subunit 1) leading to VKCFD Type 2 (VKCFD2). In addition to clotting factor deficiency, GGCX mutations can be associated with skeletal abnormalities such as bone hypoplasia, conductive hearing loss, mental retardation, and skin hyperlaxity. Here, we report an Arabic family with VKCFD1 harboring an unreported, new pathogenic variant in the GGCX gene. The proband presented at 17 months of age with severe bruising following trauma and work up demonstrated deficiencies of all Vitamin K dependent (VKD) coagulation proteins. Another sibling born 8 years later was also diagnosed with the same condition with abnormal coagulation parameters at birth. Additionally, the non-hemorrhagic manifestations diagnosed in both siblings were mid-facial hypoplasia with flat nasal bridge, dental abnormalities, and shortened distal phalanges representing a keutel syndrome-like phenotype. Both patients are currently managed with oral vitamin K supplementation with resolution of bleeding symptoms. Here we present the in-vitro assessment of the mutations effects to vitamin K supplementation and potential clinical implications. Methods: The proband, affected brother and mother, all underwent genetic evaluation at the University Clinic Bonn in Germany. DNA was isolated from the patient's blood and Sanger Sequencing was performed for the genes VKORC1 and GGCX. The identified new pathogenic variant in GGCX was further characterized by the in-vitro assay published by Ghosh et al. in 2021. Results: The brothers were found to be homozygous for c.[416G>A];[416G>A] p.(Cys139Tyr), a genetic variant in exon 4 of the GGCX gene. Mutations in VKORC1 gene leading to reduced activity for the VKD clotting factors were excluded confirming the diagnosis of VKCFD Type 1 (VKCFD1). The mother was found to be heterozygous for the same GGCX variant. The affected siblings and the mother were further genotyped for the promoter single nucleotide polymorphism in VKORC1 gene NG_011564.1:g.3588G>A (VKORC1:c.-1639 G>A) since this might correlate with the severity of the phenotypes in patients with skeletal manifestations. The brothers and mother were found to harbor VKORC1:c.-1639 GA, which has been associated with a 33% reduced VKORC1 expression. Treatment with 5mg of vitamin K resulted in increased activities of the VKD clotting factors (Table 1). However, clotting factor activities did not normalized after vitamin K supplementation. The in vitro characterization of the new identified pathogenic variant GGCX:p.C139Y (Figure 1) showed reduced activities for all VKD clotting factors, which did not reach wild type levels despite increasing concentrations of vitamin K. The levels of Matrix Gla protein (MGP), Bone Gla protein (BGLAP), and Gla-rich protein (GRP) showed almost no response to increasing amount of vitamin K. Discussion: Here, we report a new pathogenic variant in exon 4 of GGCX c.[416G>A];[416G>A] p.(Cys139Tyr) leading to VKCFD1 with reduced clotting factor activities and non-hemorrhagic manifestations. The pre and post vitamin K supplementation factor levels in the patients correlate with the in-vitro data and demonstrate failure of the clotting factor levels to normalize despite vitamin K supplementation. The in vitro data for the non-hematological VKD proteins indicate that the patients might develop a pseudoxanthoma elasticum (PXE)-like phenotype resulting into hyperlaxity of skin due to the almost zero levels of carboxylated GRP. The skeletal/bone phenotypes can be explained by the almost zero values for carboxylated MGP and GRP. To assess this in-vivo, levels of human MGP and BGLAP are currently being analyzed in the patients and mothers blood samples. These patients highlight the nuances associated with the diagnosis and management of patients with VKCFD. The antenatal management and timing of Vitamin K supplementation to prevent intrauterine bleeding is also unknown, and there may be benefit to starting early to prevent the bone and skin manifestations. Further research is warranted in rare bleeding disorders such as VKCFD. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A Phase 3, Prospective, Randomized, Double-Blind, Multicenter, Non-Inferiority Study Comparing Two Four-Factor Prothrombin Complex Concentrates for Reversal of Vitamin K Antagonist-Induced Anticoagulation in Patients Needing Urgent Surgery with Significant Bleeding Risk

Introduction: The 4-factor prothrombin complex concentrates (4F-PCCs) are very effective in urgent reversal of vitamin K antagonist (VKA) anticoagulant therapy, including correction of the International Normalized Ratio (INR). This study (LEX-209) compared the hemostatic efficacy of an investigational 4F-PCC (Octaplex®; Octapharma) with a control 4F-PCC (Beriplex® P/N, also known as Kcentra®; CSL Behring). Methods: Patients included were ≥18 years old, on VKA therapy, hospitalized for urgent surgery with a significant bleeding risk (≥50 mL) for which VKA withdrawal and intravenous vitamin K were considered to be insufficient, and had an INR ≥2.0. Patients received a single intravenous 4F-PCC dose of 25, 35, or 50 international units (IU)/kg body weight per baseline INR (2-<4, 4-6, >6, respectively); infusion rate was 0.12 mL/kg/min (~3 IU/kg/min) up to 8.4 mL/min (~210 IU/min). The primary endpoint was hemostatic efficacy rating at surgery end assessed by a blinded Independent Endpoint Adjudication Board using establised objective criteria. Secondary efficacy endpoints were the proportion of patients with INR ≤1.5, and changes in coagulation factor levels (FII, FVII, FIX, FX), at 30 (±15) minutes post-infusion. Safety endpoints included treatment-emergent adverse events (TEAEs), and thromboembolic events (TEEs) and mortality at 3, 21, and 45 days post-surgery. The Farrington-Manning test was used to assess the primary hypothesis that investigational 4F-PCC was non-inferior to control 4F-PCC (80% power, 15% non-inferiority margin). A pre-planned interim analysis was performed on the first 50% of randomized patients (≥185 patients). Results: This Phase 3 study was performed at 24 sites in the USA and Europe from June 2017-November 2021 and randomized 208 patients to investigational 4F-PCC (N=105) or control 4F-PCC (N=103). Baseline characteristics with respect to age, sex, and baseline INR for patients included in the two groups were similar, and the most common location of the planned surgery was gastrointestinal. The pre-procedural estimated maximum blood loss ≥200 mL was also similar in both groups (67.6% vs. 67.0% patients, respectively). Median dose was 25 IU/kg in both groups (range: 16-50 IU/kg investigational 4F-PCC, 15-50 IU/kg control 4F-PCC). Median (range) duration of infusion was 12 (8-50) minutes and 13 (7-30) minutes, respectively. The primary objective was met at the interim analysis and the study was stopped for non-inferiority. In the final analysis, investigational 4F-PCC was non-inferior to the control 4F-PCC, with effective hemostasis at surgery end achieved in 94.3% vs. 94.2% patients (Table 1). The proportion of patients achieving INR ≤1.5 was 78.1% with investigational 4F-PCC vs. 71.8% with control 4F-PCC (proportion difference 0.063; 95% confidence interval [CI] −0.056, 0.181; Figure 1). No patient had surgery cancelled for inadequate INR correction. Mean activities of coagulation factors (FII, FVII, FIX, FX) similarly increased in both groups. Similar proportions of patients in the investigational and control 4F-PCC groups experienced TEAEs (81.9% vs. 77.7%) and drug-related TEAEs (both 1.0%). The most common adverse reactions observed in patients who received investigational 4F-PCC were asthenia, anemia, and catheter site related reaction. One death occurred <21 days post-surgery, in the control 4F-PCC group, which was considered unrelated to the product by the investigator. Two TEEs occurred <21 days post-surgery in the investigational 4F-PCC group (unstable angina on day 5, reported as possibly related). Conclusions: The investigational 4F-PCC was non-inferior to control 4F-PCC for reversal of VKA in patients undergoing urgent surgery with significant bleeding risk. INR reductions and coagulation factor increases supported the primary endpoint. The safety profile was similar between treatment arms and consistent with previous studies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clinical and Treatment Characteristics of Infants and Toddlers Less Than Two Years of Age with Hemophilia: A Report from the Community Counts Registry

Introduction: Congenital hemophilia is an X-linked bleeding disorder often diagnosed in infants and toddlers (ITs) <2 years of age. Intracranial hemorrhage (ICH) in ITs with hemophilia remains a major complication, with a 7% occurrence, leading to disability and in some cases death. ICH in ITs may be preventable through delivery practices which avoid head trauma, especially when there is a family history (FH) of a bleeding disorder, and by early initiation of prophylaxis. The objective of this study was to examine the role of FH on mode of delivery, delivery practices, and initiation of prophylaxis, all within the context of the new treatment product emicizumab, which is approved for prophylaxis in individuals with hemophilia A (HA) of any age. We hypothesized that a FH of hemophilia would be associated with lower proportion of vaginal deliveries and instrumentation at birth and earlier age of prophylaxis initiation. Methods: We included ITs who were <2 years of age and enrolled in Community Counts, a US based Registry for Bleeding Disorders Surveillance that collects data from individuals who receive care at federally funded hemophilia treatment centers. The analysis was limited to initial surveillance visits through 2021 for ITs born ≥2011 and diagnosed with congenital HA or hemophilia B (HB), with a clotting factor activity level of <50%. Analyzed data included socio-demographics, FH of hemophilia (defined as parent report of one or more blood relative), mode of delivery (including the presence or absence of instrumentation), diagnosis type, age at diagnosis, ICH, treatment product usage, head trauma, and age at prophylaxis initiation. Summary statistics were used to characterize demographic and clinical information by FH. Differences between FH, demographic and clinical information, as well as differences between birth cohorts (2011-2015, 2015-2018, and 2019-2021) and treatment product usage were assessed for statistical significance using chi-square or parametric or non-parametric tests of differences between means as appropriate. Results: Of the 883 ITs in the analysis, most were male (98%), White (73%), non-Hispanic (78%), with HA (78%), severe disease (62%), and a known FH (70%). ITs with a FH had a lower proportion of vaginal deliveries than those with no FH (67% vs. 80%, p = 0.0006) and less instrumentation with vaginal delivery (4% vs. 9%; p = 0.02). ITs with a FH were also diagnosed earlier than those without a FH (p = <0.0001); however, age of prophylaxis initiation was not significantly different between ITs with vs without a FH (10.0 mo ± 6.2 versus 11.2 mo ± 6.0; p = 0.17) [Table 1]. Sixty-eight (8%) ITs had one or more ICH during the first two years of life. ITs with a FH were slightly less likely to have an ICH than those with no FH, but the difference was not statistically significant (7% vs 11%, p=0.08). Among all ITs with an ICH, 8 (12%) were on continuous prophylaxis at the time of ICH and 24 (35%) experienced ICH within the first month of life. Of the 24 with ICH in the first month of life, 17 (71%) had vaginal delivery and 8 (33%) reported head trauma. Regarding prophylaxis, 205 (30%) ITs with HA were on continuous prophylaxis within the first two years of life, 91% with severe HA. Thirty-five (18%) with HB were on continuous prophylaxis, 88% with severe HB. Prophylaxis with extended half-life (EHL) clotting factor and emicizumab increased over the study period for ITs with HB and HA respectively. Additionally, ITs with HA born after 2018 started prophylaxis sooner than those born in earlier years (Table 2). Conclusions: The ICH rate of 8% in ITs in this study is substantial and similar to prior reports. This study showed that a known FH of hemophilia was associated with earlier age of diagnosis and decreased rate of vaginal delivery. Nonetheless, the proportion of ICH was only slightly lower among ITs with a FH than those with no FH, and the difference did not reach statistical significance. EHL clotting factor and emicizumab use for prophylaxis increased across the birth cohorts reflecting the addition of new treatment options. The age of prophylaxis initiation decreased in ITs with HA, perhaps reflecting easier mode of administration and national guidelines supporting early initiation to prevent ICH. In ITs with hemophilia there remains opportunity to further reduce ICH by identifying at risk fetuses, optimizing delivery plans to minimize head trauma, and initiating prophylaxis even within the first month of life. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal