Rare coagulation deficiencies

Quantification of the contribution of individual coagulation factors to haemostasis using a microchip flow chamber system and reconstituted blood from deficient plasma

BACKGROUND AND OBJECTIVES

Quantifying the contribution of individual coagulation factors to haemostasis may aid our understanding of the haemostatic function in patients with rare coagulation deficiencies (RCDs) and the exploration of suitable treatments.

MATERIALS AND METHODS

Reconstituted blood prepared from specific coagulation factor-deficient plasma (factor [F]II; prothrombin, FV, FVII, FVIII, FIX, FX, FXI or FXII) and red blood cell/platelet products were used to simulate the whole blood of patients with RCD. We prepared in vitro treatment models for patients with prothrombin deficiency using coagulation factor agents and fresh frozen plasma. Haemostatic function was measured using a microchip flow chamber system at 600 s-1.

RESULTS

The haemostatic function was low, especially in blood samples reconstituted with prothrombin- and FX-deficient plasma. In a plasma transfusion model of prothrombin deficiency, haemostatic function recovered after 10% replacement with normal plasma and reached a plateau at ≧60% replacement. A treatment model of prothrombin deficiency with prothrombin complex concentrates revealed dose-dependent therapeutic effects in the range of 0-50 IU/kg.

CONCLUSION

Microchip flow chamber system-based quantification of haemostatic function using reconstituted blood could predict haemostasis and therapeutic effects of treatments in patients with prothrombin deficiency.

Frequency, clinical, and laboratory findings of platelet secretion disorders in patients referred to the specialized coagulation laboratory of the Iranian Blood Transfusion Organization

OBJECTIVES

Platelet secretion disorders (PSDs) are a subgroup of platelet function disorders (PFDs) caused by defects in the content or release of platelet granules. These patients have a variable degree of mucocutaneous bleeding tendency. The diagnostic facilities of PSDs are imitated in Iran, even in specialized coagulation laboratories. The present study aims to estimate the frequency of PSDs among patients referred to the Iranian Blood Transfusion Organization (IBTO).

METHODS

The research population includes all patients referred to the specialized coagulation laboratory of IBTO and requested platelet function and von Willebrand testing by their physicians. They were recruited between May 2022 and October 2022 if they were not diagnosed as having procoagulant defects, von Willebrand disease (VWD), Glanzmann thrombasthenia (GT), Bernard-Soulier syndrome (BSS), and platelet count <100 × 10 9 (except in the syndromic forms). Patients with a defect in response to at least two agonists in Light transmission aggregometry (LTA), one agonist in the ATP-secretion study, and/or impairment in the expression of CD62P are considered PSDs.

RESULTS

Among 121 cases referred to our center over 6 months, 40 patients fulfilled the inclusion and exclusion criteria. Ten patients were diagnosed with PSDs. Six were classified as δ-platelet secretion disorders (δ-PSD), two α-platelet secretion disorders (α-PSD), and two αδ-platelet secretion disorders (αδ-PSD).

CONCLUSIONS

The prevalence of PSDs in our population study was 25% (10/40), which seems highly prevalent. Therefore, expanding laboratory approaches to platelet function defects is necessary as a routine in our country.

Clinical Profile of Congenital Factor XIII Deficiency in Children

OBJECTIVES

Congenital Factor 13 Deficiency (FXIIID) is a rare bleeding disorder (RBD) of autosomal recessive inheritance, with an incidence of 1 in 3-5 million. The clinical symptomatology, diagnosis, and management of FXIIID are described.

METHODS

A retrospective chart review of children with FXIIID was performed from January 2000 through October 2021 at a tertiary care center in Southern India. The diagnosis was performed by the Urea clot solubility test (UCST) and Factor XIII antigen assay.

RESULTS

Twenty children (representing 16 families) were included. Male: Female ratio was 1.5:1. The median age of symptom onset was 6 mo, and the median age of diagnosis was 1 y, demonstrating a delay in diagnosis. Consanguinity was present in 15 (75%) with 4 children having affected siblings. Clinical symptomatology ranged from mucosal bleeds to intracranial bleeds and hemarthrosis, with many children having a history of prolonged umbilical bleeding in their neonatal period. Fourteen children were on cryoprecipitate prophylaxis. Four children had breakthrough bleeds due to irregular prophylaxis, including one intracranial bleed due to a delay in cryoprecipitate prophylaxis during the covid pandemic.

CONCLUSIONS

Congenital FXIIID presents with a wide range of bleeding manifestations. The high prevalence of consanguinity in Southern India can be a cause of FXIIID's high prevalence in this region. There is a propensity for intracranial bleeding with a significant number having this at first presentation. Regular prophylaxis is required and feasible to prevent potentially fatal bleeds.

Genetic Landscape of Factor VII Deficiency: Insights from a Comprehensive Analysis of Pathogenic Variants and Their Impact on Coagulation Activity

Congenital factor VII (FVII) deficiency is a rare genetic bleeding disorder characterized by deficient or reduced activity of coagulation FVII. It is caused by genetic variants in the F7 gene. We aimed to evaluate the rate of detection of pathogenic variants in the F7 gene in a large group of patients with FVII deficiency and investigate the correlations between the F7 genotype and FVII activity (FVII:C). Moreover, the influence of the common genetic variant rs6046: c.1238G>A; p.(Arg413Gln), designated as the M2 allele, on FVII:C was investigated. Genetic analysis of the F7 gene was performed on 704 index patients (IPs) using either direct Sanger- or next-generation sequencing. Genetic variants were detected in 390 IPs, yielding a variant detection rate (VDR) of 55%. Notably, the VDR exhibited a linear decline with increasing FVII:C levels. We identified 124 genetic variants, of which 48 were not previously reported. Overall, the frequency of the M2 allele was considerably higher in patients with mild deficiency (FVII:C > 20 IU/dl). Furthermore, IPs lacking an identified pathogenic variant exhibited a significantly higher prevalence of the M2 allele (69%) compared to IPs with a disease-causing variant (47%). These results strongly support the association of the M2 allele with decreased FVII:C levels. This study shows the utility of FVII:C as a predictive marker for identifying pathogenic variants in patients with FVII deficiency. The M2 allele contributes to the reduction of FVII:C levels, particularly in cases of mild deficiency.

Consanguineous Marriage and Its Association With Genetic Disorders in Saudi Arabia: A Review

Consanguineous marriages, where spouses are related by blood, have been a longstanding practice in human history. The primary medical concern with consanguineous marriages is the increased risk of genetic disorders. When closely related individuals reproduce, there is a higher probability that both parents carry the same genetic mutation. In Arab countries, especially Saudi Arabia, the rate of consanguineous marriage is high compared with Western European and Asian countries. This high rate is directly proportionate with elevated risk of genetic disorders, including congenital heart diseases, renal diseases, and rare blood disorders. Additionally, it was noted that the rate of negative postnatal outcomes is higher in consanguineous marriages compared with the general population. These observations indicate the necessity of tackling this area and highlighting the consequences of this practice. In this review, we aim to discuss the current evidence regarding the association between consanguineous marriages and genetic disorders in Saudi Arabia.

Postmortem diagnosis of severe factor X deficiency in a fetus with intracranial hemorrhage resulting in intrauterine death

In patients with severe congenital factor X deficiency, spontaneous intracranial hemorrhage (ICH) is particularly frequent in early childhood. We describe a case of fetal death at 26 weeks due to massive ICH. Gene panel analysis of postmortem samples revealed homozygosity for a pathologic F10 gene variant (c.1210T>C, p.Cys404Arg), which impedes correct folding of the catalytic serine protease domain and, therefore, causes a significant reduction in FX levels. The parents, not consanguineous but of the same ethnic community, were found to be heterozygous for this variant and did not have any personal or family history of abnormal bleeding. To the best of our knowledge, this is the first reported case of severe FX deficiency resulting in ICH diagnosed through postmortem genetic analysis. It illustrates the importance of exploring the etiology of fetal or neonatal ICH, which may impact future pregnancies, and the treatment of a potential coagulopathy in the child.

National strategic advocacy to manage patients with inherited bleeding disorders in low and lower-middle income countries

INTRODUCTION

Inherited bleeding disorders (IBDs) including hemophilia, von Willebrand disease, platelet disorders, mucocutaneous bleeding disorders and coagulation factor deficiencies are rarely found and under-recognized in low and lower-middle-income countries. Some patients succumbed to serious bleeding without diagnosis and treatment during childhood.

AREA COVERED

Diagnosis, management, and prevention should be integrated into the existing health care system. Although some countries have not implemented appropriate health care infrastructure, an initiative plan should be set up by cooperation of experienced experts and health care providers. Identification of patients with IBDs should be started in the antenatal setting to search for females at risk of carrier state. The investigations include bleeding assessment, mixing venous clotting time, coagulogram, coagulation factor assay and mutation detection. Genotypic analysis is helpful for confirming the definite diagnosis, carrier detection as well as prenatal diagnosis for females at risk of bearing an offspring with severe bleeding manifestations. Management involves replacement therapy ranging from blood component to virus-inactivated factor concentrate. Appropriate research is an essential backbone for improving patients' care.

EXPERT OPINION

Effective national strategic advocacy to manage patients with IBDs requires intensive collaboration among policy makers, health care providers, patients, and family members.

The Magic of Proteases: From a Procoagulant and Anticoagulant Factor V to an Equitable Treatment of Its Inherited Deficiency

Proteostasis, i.e., the homeostasis of proteins, responsible for ensuring protein turnover, is regulated by proteases, which also participate in the etiopathogenesis of multiple conditions. The magic of proteases is such that, in blood coagulation, one same molecule, such as coagulation factor V, for example, can perform both a procoagulant and an anticoagulant function as a result of the activity of proteases. However, this magic has an insidious side to it, as it may also prevent the completion of the clinical value chain of factor V deficiency. This value chain encompasses the discovery of knowledge, the transfer of this knowledge, and its translation to clinical practice. In the case of rare and ultra-rare diseases like factor V deficiency, this value chain has not been completed as the knowledge acquisition phase has dragged out over time, holding up the transfer of knowledge to clinical practice. The reason for this is related to the small number of patients afflicted with these conditions. As a result, new indications must be found to make the therapies cost-effective. In the case of factor V, significant research efforts have been directed at developing a recombinant factor V capable of resisting the action of the proteases capable of inactivating this factor. This is where bioethics and health equity considerations come into the equation.

A Case Report of Congenital Afibrinogenemia and Literature Review of Management of Post-circumcision Bleeding

We present a case of bleeding from circumcision in a full-term newborn male resulting from a rare coagulopathy, congenital afibrinogenemia, and a review of the literature regarding the management of bleeding after circumcision. Bleeding was managed with silver nitrate, suturing, thrombin powder, Arista^TM AH (absorbable hemostatic particles; Becton, Dickinson and Company, Franklin Lakes, USA), FFP (fresh frozen plasma), and cryoprecipitate. The Fibrinogen level was less than 30 mg/dl (ref 150-430 mg/dl). The diagnosis of congenital afibrinogenemia was confirmed by a gene test. The baby was found to have a heterozygous pathogenic variant (c.510+1G>T) and a heterozygous likely pathogenic variant (c.1037del) in the FGA gene.

Pregnancy, childbirth and neonatal outcomes of women with rare inherited coagulation disorders

Background

We aimed to describe the characteristics and the pregnancy outcomes of women with rare inherited coagulation factor disorders managed at a tertiary obstetric-haematology unit in the United Kingdom.

Methods

A retrospective service evaluation was conducted using routinely collected medical records. Descriptive analyses were applied to investigate pregnancy, childbirth and neonatal management and outcomes.

Results

Overall, 20 patients with rare inherited coagulation disorders were included who birthed 30 live infants from 29 pregnancies. Regarding maternal bleeding outcomes, 3% experienced antepartum haemorrhage, 38% of pregnancies experienced primary post-partum haemorrhage, and none experienced secondary post-partum haemorrhage. Five (17%) neonates had cranial ultrasound scans for imaging to investigate for a neonatal haemorrhage, which were all normal.

Conclusions

Although women with rare inherited coagulation disorders may be more susceptible to complications in pregnancy, within this cohort there was no evidence that the condition led to increased morbidity or mortality when best practices were observed.

Pharmacokinetics, efficacy and safety of a novel fibrinogen concentrate in pediatric patients with congenital afibrinogenemia

INTRODUCTION

Congenital afibrinogenemia treatment with plasma-derived fibrinogen concentrates in pediatric patients is limited. This study investigated the pharmacokinetics, surrogate efficacy, and safety of a plasma-derived fibrinogen concentrate (FIB Grifols) in pediatric patients with congenital afibrinogenemia.

METHODS

Patients aged <18 years old diagnosed with congenital afibrinogenemia were included in this prospective, multinational, phase 1-2, single-arm study. After a single dose of a plasma-derived fibrinogen concentrate (70 mg/kg body weight), pharmacokinetic parameters were determined from plasma fibrinogen activity (Clauss method) and antigen method (ELISA), and calculated by noncompartmental and population pharmacokinetic (popPK) models. Patients were followed up over 14 days. Efficacy variables were the mean change on thromboelastographic variables (maximum clot firmness [MCF], alpha angle [ α ]) and coagulation tests (prothrombin time, activated partial thromboplastin time, and thrombin time) 1 h postinfusion. Safety parameters were assessed.

RESULTS

Eleven patients with a median (range) age 8.80 (3.7-12.7) years were treated with the plasma-derived fibrinogen concentrate. Using the popPK modeling, fibrinogen activity reached a mean (standard deviation) Cmax of 1.3 (0.225) g/l, half-life ( t1/2 ) of 60.6 (4.48) h and incremental in vivo recovery (IVR) of 1.86 (0.322) (mg/dl)/(mg/kg). Surrogate efficacy was demonstrated by significant increase in MCF (9.23 [3.94] mm; P  < 0.001; 95% confidence interval 6.58, 11.87). All coagulation times were significantly shortened after fibrinogen concentrate infusion. Adverse events were mild or moderate in severity, and unrelated to fibrinogen concentrate.

CONCLUSIONS

In pediatric patients with congenital afibrinogenemia, plasma-derived fibrinogen concentrate revealed a favorable and specific pharmacokinetic profile, demonstrated efficacy in coagulation and was safe and well tolerated.

Phenotypic and genotypic characterization of two factor VII deficiency patients from southeastern China

The congenital factor VII deficiency (FVIID) is a rare autosomal recessive haemorrhagic disease caused by mutations in the F7 gene. The aim of this study was to identify the mutations causing FVII deficiency and explain the genotype-phenotype association in two unrelated Chinese patients. Mutation detection was conducted by sequencing the whole F7 gene coding exons, exon-intron boundaries and the untranslated regions of 3' and 5'. Then, the genetic information was analyzed to predict the structures of the mutated proteins. A total of four different mutations were detected, including three missense mutations (c.64G>A, c.286A>G, and c.722C>A, predicting p.Gly22Ser, p.Arg96Gly, p.Thr241Asn, respectively) and one insertion mutation (c.204_205insCGGC, predicting p. Leu68Argfs ∗ 37), among which two were reported for the first time (p.Arg96Gly, p.Leu68Argfs ∗ 37). Multiple sequence alignments of FVII protein revealed that the residues p.Arg96 and p.Thr241 were highly conserved. The novel missense mutation p.Arg96Gly was determined as damaging with online software Polyphen-2 and SIFT. We investigated two asymptomatic patients diagnosed with severe FVII deficiency and identified two novel mutations (the mutation p.Arg96Gly and p.Leu68Argfs ∗ 37). Identification of the F7 mutations was important for genetic counseling and accurate prediction of the inheritance pattern.

Evaluating for Suspected Child Abuse: Conditions That Predispose to Bleeding

Child abuse might be suspected when children present with cutaneous bruising, intracranial hemorrhage, or other manifestations of bleeding. In these cases, it is necessary to consider medical conditions that predispose to easy bleeding or bruising. When evaluating for the possibility of bleeding disorders and other conditions that predispose to hemorrhage, it is important for pediatricians to consider the child's presenting history, medical history, and physical examination findings before initiating a laboratory investigation. Many medical conditions can predispose to easy bleeding. Before ordering laboratory tests for a disease, it is useful to understand the biochemical basis and clinical presentation of the disorder, condition prevalence, and test characteristics. This technical report reviews the major medical conditions that predispose to bruising or bleeding and should be considered when evaluating for abusive injury.

A novel F13A1 gene mutation (Arg208Pro) in a Chinese patient with factor XIII deficiency

The objective of the study was to analyse a novel F13A1 gene mutation in a Chinese patient with factor XIII (FXIII) deficiency and explore the molecular mechanism. Pedigree investigation, clinical diagnosis, phenotypic and genetic analysis were conducted. The F13A1 gene was amplified by PCR and directly sequenced. Online bioinformatics software was needed to analyse the mutation. A novel mutation c.515G>C (p.Arg208Pro) in exon 4 was found in the proband. Protein Arg208 is conserved highly among homologous species. Bioinformatics software showed that Arg208Pro mutation might affect the protein function. We preliminarily believed the mutation Arg208Pro was responsible for the decrease FXIII level. We reported a novel mutation in the F13A1 gene, which can flesh out the mutant library.

The Vascular Endothelium and Coagulation: Homeostasis, Disease, and Treatment, with a Focus on the Von Willebrand Factor and Factors VIII and V

The vascular endothelium has several important functions, including hemostasis. The homeostasis of hemostasis is based on a fine balance between procoagulant and anticoagulant proteins and between fibrinolytic and antifibrinolytic ones. Coagulopathies are characterized by a mutation-induced alteration of the function of certain coagulation factors or by a disturbed balance between the mechanisms responsible for regulating coagulation. Homeostatic therapies consist in replacement and nonreplacement treatments or in the administration of antifibrinolytic agents. Rebalancing products reestablish hemostasis by inhibiting natural anticoagulant pathways. These agents include monoclonal antibodies, such as concizumab and marstacimab, which target the tissue factor pathway inhibitor; interfering RNA therapies, such as fitusiran, which targets antithrombin III; and protease inhibitors, such as serpinPC, which targets active protein C. In cases of thrombophilia (deficiency of protein C, protein S, or factor V Leiden), treatment may consist in direct oral anticoagulants, replacement therapy (plasma or recombinant ADAMTS13) in cases of a congenital deficiency of ADAMTS13, or immunomodulators (prednisone) if the thrombophilia is autoimmune. Monoclonal-antibody-based anti-vWF immunotherapy (caplacizumab) is used in the context of severe thrombophilia, regardless of the cause of the disorder. In cases of disseminated intravascular coagulation, the treatment of choice consists in administration of antifibrinolytics, all-trans-retinoic acid, and recombinant soluble human thrombomodulin.

Fibrinogen, Fibrinogen-like 1 and Fibrinogen-like 2 Proteins, and Their Effects

Fibrinogen (Fg) and its derivatives play a considerable role in many diseases. For example, increased levels of Fg have been found in many inflammatory diseases, such as Alzheimer's disease, multiple sclerosis, traumatic brain injury, rheumatoid arthritis, systemic lupus erythematosus, and cancer. Although associations of Fg, Fg chains, and its derivatives with various diseases have been established, their specific effects and the mechanisms of actions involved are still unclear. The present review is the first attempt to discuss the role of Fg, Fg chains, its derivatives, and other members of Fg family proteins, such as Fg-like protein 1 and 2, in inflammatory diseases and their effects in immunomodulation.

Quality of clinical studies present in the package inserts of coagulation factors used in the treatment of hemophilia

OBJECTIVE

To identify and analyze the quality of scientific evidence from clinical efficacy studies present in the package inserts of coagulation factors, used in the treatment of hemophilia A and B.

METHODS

Documentary study developed in two stages. The first stage consisted of identifying the medicine packages inserts electronically registered in the Brazilian Health Regulatory Agency, and analyzing the availability of the bibliographic references cited therein. This analysis was conducted in the PubMed, SciELO, Google Scholar, and Web of Science databases. The second step was the analysis of the methodological quality of the efficacy studies. Two trained researchers used the Cochrane Collaboration Risk of Bias version 5.1.0 tools for methodological quality analysis, and Review Manager 5.4 software to generate the risk of bias graph.

RESULTS

Of the 17 medicines listed, 7 had referenced package inserts. Of these, 10 studies were eligible for analysis of methodological quality. More than half of the analyzed studies did not control for selection, performance, and detection bias. A total of 100% controlled attrition and reporting biases, and 50% had a high risk of conflict of interest.

CONCLUSION

The biases present are significant and may have influenced the overestimation of the effects of the outcomes of each of the studies.

How to use a coagulation screen

A coagulation screen is an important screening test when investigating a child who presents with easy bruising or bleeding. Interpretation of a coagulation screen can be challenging for clinicians. Evolution of the haemostasis system during childhood means normal ranges vary with age and needs to be interpreted alongside the clinical information. It is essential to consider preanalytical variables when interpreting a coagulation screen, and the reason for the investigation must always be considered. It is important that the sample is taken under optimal conditions, including sample technique, use of the correct bottle and prompt transport to the laboratory. An abnormal coagulation screen may indicate an underlying congenital bleeding disorder or an acquired bleeding disorder, or may be due to sampling error. Limitations of the coagulation screen are essential to be aware of, as some children with normal coagulation screen results may have bleeding disorders. Conversely, an abnormal coagulation screen does not always indicate a bleeding disorder.

Gastrointestinal Bleeding in Congenital Bleeding Disorders

Gastrointestinal bleeding (GIB) is serious, intractable, and potentially life-threatening condition. There is considerable heterogeneity in GIB phenotypes among congenital bleeding disorders (CBDs), making GIB difficult to manage. Although GIB is rarely encountered in CBDs, its severity in some patients makes the need for a comprehensive and precise assessment of underlying factors and management approaches imperative. Initial evaluation of GIB begins with assessment of hematological status; GIB should be ruled out in patients with chronic anemia, and in presentations that include hematemesis, hematochezia, or melena. High-risk patients with recurrent GIB require urgent interventions such as replacement therapy for treatment of coagulation factor deficiency (CFD). However, the best management strategy for CFD-related bleeding remains controversial. While several investigations have identified CBDs as potential risk factors for GIB, research has focused on assessing the risks for individual factor deficiencies and other CBDs. This review highlights recent findings on the prevalence, management strategies, and alternative therapies of GIB related to CFDs, and platelet disorders.

Proposed mechanism for rare thrombotic events after use of some Covid-19 vaccines

Administration of AstraZeneca/Oxford and Johnson & Johnson/Janssen Covid-19 vaccines which use an adenovirus vector for DNA delivery has been associated with very rare thromboembolic complications coupled with an immune response to platelet factor 4 protein. The cause of this has not yet been identified. It is known that binding of coagulation factor proteins to the surface of some adenoviruses can protect their function. Here I propose that the thromboembolic events are caused by impairment of coagulation factor X binding to the virus capsid. The unprotected capsid then stimulates an immune response leading to platelet activation, increased thrombogenicity and formation of an antibody complex with platelet factor 4. Impaired binding of factor X may be due to an undiagnosed mutation in affected individuals. Options to test this mechanism experimentally and potential remedial actions to resolve the hazard are described. This mechanism offers a remedial route to address concerns about the safety of these vaccines, which are otherwise well-positioned to deliver global Covid-19 immunity across diverse healthcare economies.

[Congenital factor X deficiency: a retrospective analysis of 11 cases]

Objective: To analyze the clinical characteristics, laboratory examination, diagnosis, treatment, and outcome of hereditary factor Ⅹ (FⅩ) deficiency. Methods: Clinical data of 11 patients with congenital FⅩ deficiency were retrospectively analyzed from July 2009 to February 2021. Results: There were 3 males and 8 females. Median age was 39 (5-55) years. The media duration of follow-up was 81.67 (1.87-142.73) months. Of the 11 patients, 10 had bleeding symptoms, 7 had ecchymosis or hemorrhage after skin bump, 7 had nosebleed, 6 had gingival hemorrhage, and 1 had muscle hematoma. Among the female patients, 6 had menorrhagia and 1 experienced bleeding after vaginal delivery. Family history of FⅩ deficiency was found in one case. Eight patients had a history of surgery, and four had postoperative bleeding. Laboratory findings were characterized by significantly prolonged activated partial thromboplastin time, prothrombin time, and decreased FⅩ activity (FⅩ∶C) . Four cases underwent gene mutation analysis and five new mutations were found. Four cases were treated with prothrombin complex concentrates (PCC) and seven cases with fresh frozen plasma (FFP) . One female patient had significantly reduced menstrual volume after PCC prophylactic therapy. One patient received FFP for prophylactic infusion with no bleeding during and after the operation. Conclusion: Most patients with congenital FⅩ deficiency had bleeding symptoms and there was no significant correlation between severity of bleeding symptoms and FⅩ∶C. Prophylaxis should be applied in patients with severe bleeding tendencies. Gene mutation test is significant for screening, diagnosis, and prognosis prediction of congenital FX deficiency.

Cell therapy for factor V deficiency: An approach based on human decidua mesenchymal stem cells

Deficiency of factor V is a congenital autosomal recessive coagulopathy associated with mutations in the F5 gene that results in mild-to-severe bleeding episodes. Factor V is a component of the prothrombinase complex responsible for accelerating conversion of prothrombin to thrombin. At the present time there are no therapeutic factor V concentrates available. This study was designed to lay the preliminary foundations for future cell-based therapy for patients with severe factor V deficiency. The study showed that hepatospheres, which produce coagulation factors VIII, IX, and V, synthetize and store intracellular glycogen and express albumin levels up to 8 times higher than those of undifferentiated cells. Factor IX and factor V gene expression increased significantly in hepatospheres as compared to undifferentiated cells, whereas factor VIII gene expression remained constant. The factor V protein was detected in the hepatospheres´ secretome. Considering the enormous potential of mesenchymal stem cells as therapeutic agents, this study proposes a highly reproducible method to induce differentiation of mesenchymal stem cells from human placenta to factor V-producing hepatospheres. This strategy constitutes a preliminary step towards a curative treatment of factor V deficiency through advanced therapies such as cell therapy.

Rare Coagulation Factor Deficiencies (Factors VII, X, V, and II)

Although rare clotting factor deficiencies primarily referred to as rare bleeding disorders (RBD), including factors II, V, VII, and X, make up ∼5% of all inherited bleeding disorders worldwide, each of these clotting factors play a critical role in the coagulation cascade. Incomplete bleeding evaluation or misinterpretation of laboratory studies can result in delayed diagnoses that ultimately affect patient outcomes. Bleeding manifestations can range from mild to severe, but the most common are mucocutaneous bleeding. The ideal treatment in RBD is dedicated single-factor concentrates that can be used for acute bleeding events, surgical management, and prophylaxis.

Factor XIII deficiency in two Spanish families with a novel variant in gene F13A1 detected by next-generation sequencing; symptoms and clinical management

Coagulation factor XIII (FXIII) has a major role in coagulation stabilizing the haemostatic clot. FXIII deficiency is associated with an increased risk of bleeding. Severe phenotypes lead to spontaneous, traumatic and surgical bleeding. Umbilical cord bleeding is especially common, and intracranial bleeding may occur in up to one third of patients without prophylaxis. In this work, we used NGS for screening all the coding and intronic boundary regions of F13A1 and F13B genes in two families affected by severe FXIII deficiency. Outcome confirmation analysis and variant studies in related patients was done by Sanger sequencing. Two variants were found: c.34A > G (p.Arg12Gly; NM_00129.3) and c.514C > T (p.Arg172Ter; NM_00129.3), both located in the F13A1 gene. The variant p.Arg172Ter is already described in literature and was found in homozygosis in one family and in compound heterozygosis in the other family. The variant p.Arg12Gly variant has not been described previously. This variant is located in the activation peptide of the FXIII A-subunit which is highly conserved among FXIII homologs. Given the high risk of dangerous bleeding and early manifestation in severe FXIII-deficient patients, a prompt genetic confirmation is imperative. In this sense, NGS technology allows a rapid and simultaneous analysis of all regions of all the genes involved in the pathology.

Preoperative bleeding risk assessment with ISTH-BAT and laboratory tests in patients undergoing elective surgery: A prospective cohort study

BACKGROUND

Patients with inherited haemorrhagic disorders may bleed during surgery. No questionnaire on bleeding diathesis has been yet validated for the preoperative period and current guidelines provide conflicting recommendations.

AIM

We aimed to assess if preoperative assessment with ISTH-BAT (International Society on Thrombosis and Haemostasis Bleeding Assesment Tool) and laboratory screening tests is useful to identify mild previously undiagnosed bleeding disorders (BDs) and to predict bleeding complications in selected patients undergoing elective surgery.

METHODS

Consecutive patients undergoing elective surgery received ISTH-BAT evaluation and laboratory screening for platelet count, Prothrombin Time (PT) and activated Partial Thromboplastin Time (aPTT). Subjects with an abnormal ISTH-BAT and/or laboratory results underwent further testing, and they were compared with a 1:1 random gender-, age- and type of surgery- matched control group.

RESULTS

Overall, 1502 consecutive surgical patients (1186 adults, 316 children) were enrolled. Of these, 83 (5.5%, 95% confidence interval 4.4-6.8) patients (37 adults and 46 children) had an abnormal ISTH-BAT, and/or prolonged PT and/or prolonged aPTT and/or low platelet count; of them, one subject had low von Willebrand factor level, three Factor XII deficiency and four anticardiolipin and/or antiB2GPI antibodies. No major bleeding was reported in these 83 patients and their controls.

CONCLUSION

ISTH-BAT and laboratory screening tests do not accurately detect mild BDs in selected patients undergoing elective surgery.

Novel splicing (c.6529-1G>T) and missense (c.1667G>A) mutations causing factor V deficiency

Congenital factor V deficiency (FVD) is a rare bleeding disorder. In this study, we investigated the genetic basis in an African American patient with factor V activity 3%. Custom sequence capture and targeted next-generation (NGS) sequencing of the F5 gene were undertaken followed by PCR and Sanger sequencing. Two novel variants were identified. In silico analyses correlated clinically with the patient's factor V activity and hemorrhagic tendency. A review of the literature regarding these genomic alterations is presented. We described two novel mutations causing moderate FVD. The first, Chr1:g.169483698C>A with cDNA change (F5):c.6529-1G>T, occurred in a conserved nucleotide at the canonical acceptor splice site of intron 24. The second, Chr1:g.169515775C>T with cDNA change (F5):c.1667G>A, was a missense variant of exon 11, affecting a highly conserved amino acid in the A2 domain. Further research into the mechanisms of F5 mutations leading to FVD and residual factor V expression are needed.

Occurrence and management of severe bleeding episodes in patients with hereditary factor X deficiency

Vitamin K-dependent factor X (FX) plays an important role in thrombin formation, and a deficiency in FX can cause impaired coagulation, the severity of which is usually correlated with the degree of deficiency. Due to the critical role that FX plays in the coagulation cascade, FX deficiency is associated with a higher risk of bleeding than deficiencies in other coagulation factors. Patients with the hereditary autosomal-recessive homozygous form of FX deficiency, which occurs in approximately 1:1,000,000 individuals worldwide, are often diagnosed when they present with spontaneous life-threatening haemorrhage (most often intracranial haemorrhage) during the first month of life. In addition to central nervous system bleeds, other severe bleeding types experienced by such patients may include umbilical cord bleeding, gastrointestinal or pulmonary haemorrhage, intramuscular haematomas and/or haemarthrosis. Delayed treatment or inadequate replacement of FX may result in developmental delays, musculoskeletal disabilities or death. The high risk of recurrent severe bleeding necessitates prophylactic replacement therapy for many individuals with severe FX deficiency. Available products for replacement therapy include plasma-derived FX concentrate and prothrombin complex concentrates. Fresh-frozen plasma may be used when concentrates are not available but is a less efficient means of FX replacement. This article reviews the literature on severe bleeding in individuals with hereditary FX deficiency and discusses current treatment options.

Identification of a novel mutation in congenital afibrinogenemia in Iranian patients

Congenital afibrinogenemia is a rare autosomal recessive disorder that is caused by defects in the fibrinogen. Fibrinogen is a hexameric glycoprotein made of two pairs of three homologous polypeptide chains including Aα, Bβ, and γ that are encoded by three genes named FGA, FGB, and FGG. We aim to study four Iranian families who were referred to our lab for molecular diagnosis of afibrinogenemia. Genomic DNA was extracted from whole blood and Sanger sequencing was performed using primers for all exons and exon-intron junctions of FGA, FGB, and FGG genes. Pathogenicity of the variants was predicted using different in-silico tools and was interpreted according to the American College of Medical Genetics and Genomics guideline. We found three types of mutations in the studied families; two were in the FGA gene and one was in the FGB gene including a nonsense, a novel splicing mutation, and two deletion ones. The nonsense and the deletion mutations may cause a truncated protein and are likely pathogenic and pathogenic, respectively. The novel mutation of splicing found in the FGB gene is a pathogenic one and can break the wild-type acceptor site. Studying mutations in afibrinogenemia patients can expand our knowledge about this disease in Iran.

Consanguineous marriage and rare bleeding disorders

Introduction: Rare bleeding disorders (RBDs) are a heterogeneous group of bleeding disorders. Consanguineous marriage is the favorite partnership in many communities among a population of more than a billion. Consanguineous marriages allow the defective recessive genes in RBDs to remain in the family. Clinical approach to RBDs is not as straightforward as typical bleeding disorders, which are secondary to scarcity and variation of RBDs. However, in many developing countries, the limitations of diagnostic facilities, the supply of therapeutic coagulation concentrates, health budgets, and optimal health-care infrastructures may intensify the clinical practice of RBDs.Areas covered: The author addresses the role of consanguineous marriage in the incidence of RBDs and what preventive steps can be considered to minimize the incidence of RBDs. A literature review of PubMed and google Scholar was conducted in November of 2020 using the relevant keywords.Expert opinion: This review addresses the prevalence of consanguineous marriages in Middle Eastern countries and the various reasons behind the coexistence of consanguineous marriage with RBDs. Finally, prevention steps that may be considered by health-care systems to minimize the incidence of rare bleeding disorders have been discussed. Health-care systems should train partners with the intention of consanguineous marriage on the downside of consanguinity.

Diagnosis, therapeutic advances, and key recommendations for the management of factor X deficiency

Factor X deficiency is a rare coagulation disorder that can be hereditary or acquired. The typology and severity of the associated bleeding symptoms are highly heterogeneous, adding to the difficulties of diagnosis and management. Evidence-based guidelines and reviews on factor X deficiency are generally limited to publications covering a range of rare bleeding disorders. Here we provide a comprehensive review of the literature on factor X deficiency, focusing on the hereditary form, and discuss the evolution in disease management and the evidence associated with available treatment options. Current recommendations advise clinicians to use single-factor replacement therapy for hereditary disease rather than multifactor therapies such as fresh frozen plasma, cryoprecipitate, and prothrombin complex concentrates. Consensus in treatment guidelines is still urgently needed to ensure optimal management of patients with factor X deficiency across the spectrum of disease severity.

Pediatric Fibrinogen PART II-Overview of Indications for Fibrinogen Use in Critically Ill Children

Bleeding is frequently seen in critically ill children and is associated with increased morbidity and mortality. Fibrinogen is an essential coagulation factor for hemostasis and hypofibrinogenemia is an important risk factor for bleeding in pediatric and adult settings. Cryoprecipitate and fibrinogen concentrate are often given to critically ill children to prevent bleeding and improve fibrinogen levels, especially in the setting of surgery, trauma, leukemia, disseminated intravascular coagulopathy, and liver failure. The theoretical benefit of fibrinogen supplementation to treat hypofibrinogenemia appears obvious, yet the evidence to support fibrinogen supplementation in children is sparce and clinical indications are poorly defined. In addition, it is unknown what the optimal fibrinogen replacement product is in children and neonates or what the targets of treatment should be. As a result, there is considerable variability in practice. In this article we will review the current pediatric and applicable adult literature with regard to the use of fibrinogen replacement in different pediatric critical care contexts. We will discuss the clinical indications for fibrinogen supplementation in critically ill children and the evidence to support their use. We summarize by highlighting current knowledge gaps and areas for future research.

Plasma viscosity pattern and erythrocyte aggregation in two patients with congenital afibrinogenemia

: In this case report, we examine the behavior of plasma viscosity, explored at high and low shear rates, and erythrocyte aggregation in two patients with congenital afibrinogenemia, a clinical disorder firstly described in 1920 and that has an estimated incidence of 1 : 1-200 0000. The two hemorheological parameters examined by us showed a marked decrease in both patients, in one of whom erythrocyte aggregation was even undetectable. Keeping in mind that spontaneous thrombosis (venous and arterial) has been often described in congenital afibrinogenemia, it can be hypothesized that the decrease in plasma viscosity and erythrocyte aggregation might cause a reduction of the endothelial synthesis and release of nitric oxide through the fall of the wall shear stress.

Inherited bleeding disorders in oral procedures. Assessment of prophylactic and therapeutic protocols: a scoping review

BACKGROUND

This scoping review aimed to map available evidence regarding minor/major oral procedures in patients with inherited bleeding disorders (IBDs).

METHODS

Studies in medicine or dentistry that reported minor and major oral procedures in individuals presenting IBDs (e.g. haemophilia A or B, von Willebrand disease) were selected. Search and screening were performed in PubMed/Medline, Scopus, Web of Science and Cochrane Library by two independent researchers.

RESULTS

Initial search yielded 4152 citations, of which 257 were included in the final analysis. Most of the evidence for prophylaxis use was derived from observational studies and the most-commonly reported prophylactic protocols were fresh frozen plasma and factor VIII concentrate. A considerable number of studies reported postoperative complications and hospitalizations.

CONCLUSION

The present study identified that (1) there is room for new studies to assess the use of antifibrinolytic agents with no factor replacement; (2) to date, the use of factor replacement therapy is the most indicated approach when treating patients with IBDs with adjunct systemic or local antifibrinolytic agents to reduce post-operative complications; and (3) there is a critical need for high-quality evidence studies since much of the conclusions of the included studies are not supported by statistical analysis.

Familial Multiple Coagulation Factor Deficiencies (FMCFDs) in a Large Cohort of Patients-A Single-Center Experience in Genetic Diagnosis

Background: Familial multiple coagulation factor deficiencies (FMCFDs) are a group of inherited hemostatic disorders with the simultaneous reduction of plasma activity of at least two coagulation factors. As consequence, the type and severity of symptoms and the management of bleeding/thrombotic episodes vary among patients. The aim of this study was to identify the underlying genetic defect in patients with FMCFDs. Methods: Activity levels were collected from the largest cohort of laboratory-diagnosed FMCFD patients described so far. Genetic analysis was performed using next-generation sequencing. Results: In total, 52 FMCFDs resulted from coincidental co-inheritance of single-factor deficiencies. All coagulation factors (except factor XII (FXII)) were involved in different combinations. Factor VII (FVII) deficiency showed the highest prevalence. The second group summarized 21 patients with FMCFDs due to a single-gene defect resulting in combined FV/FVIII deficiency or vitamin K–dependent coagulation factor deficiency. In the third group, nine patients with a combined deficiency of FVII and FX caused by the partial deletion of chromosome 13 were identified. The majority of patients exhibited bleeding symptoms while thrombotic events were uncommon. Conclusions: FMCFDs are heritable abnormalities of hemostasis with a very low population frequency rendering them orphan diseases. A combination of comprehensive screening of residual activities and molecular genetic analysis could avoid under- and misdiagnosis.

Genetic Analysis of Afibrinogenemia and Hypofibrinogenemia: Novel Mutations in the FGB Gene in the Turkish Population

INTRODUCTION

Congenital afibrinogenemia is a rare autosomal recessive disorder characterized by bleeding that varies from mild to severe and by complete absence or extremely low levels of plasma and platelet fibrinogen. Hypofibrinogenemia is characterized by fibrinogen levels <1.5 g/L.

OBJECTIVE

In this study, we analyzed fibrinogen beta chain gene mutations in Turkish afibrinogenemia and hypofibrinogenemia patients.

METHODS

We evaluated 20 afibrinogenemia and hypofibrinogenemia patients and 80 healthy controls. We have sequenced all exons of the FGB gene using the DNA isolated from the peripheral blood samples of patients and controls.

RESULTS AND CONCLUSION

We found a nonsense mutation in exon 4 at nucleotide 630 that encoded serine amino acid, and in the same exon a missense mutation of T to C at nucleotide 647, resulting in a transition from leucine to proline (p.L198P) in a child with hypofibrinogenemia. These mutations have been shown for the first time in the same patient of Turkish descent. Furthermore, there was a novel heterozygous guanine-to-adenine nucleotide change in exon 3. This caused the change of arginine amino acid to threonine amino acid at position 136 (p.A136T) in a protein, which has not been described in the literature before.

Molecular mechanism of a novel Ser362Asn mutation causing inherited FX deficiency in a Chinese family

Factor X (FX) deficiency is an inherited autosomal recessive bleeding disorder. Here, we analyzed a proband with FX deficiency in a Chinese family. Genetic analysis revealed that the proband and his affected sister was homozygous for c.1085G>A mutation, corresponding to a Ser362Asn substitution. In vitro expression experiments showed that the FX Ser362Asn mutation led to a significant reduction in activity levels in the culture medium. This Ser to Asn substitution may change the shape of the active site. Moreover, simulations of molecular dynamics indicated that the binding energy of the FX Ser362Asn to the substrate is higher than that of wild type and the side-chain conformation of the catalytic residue His276 (His42) is changed. This impairs the conformational switch of the protein from zymogen to proteinase, thus causing the functional defect of FX protein. Our findings suggest that the Ser362Asn substitution is a pathogenic mutation that causes inherited FX deficiency.

Disruption of the kringle 1 domain of prothrombin leads to late onset mortality in zebrafish

The ability to prevent blood loss in response to injury is a conserved function of all vertebrates. Complete deficiency of the central clotting enzyme prothrombin has never been observed in humans and is incompatible with postnatal life in mice, thus limiting the ability to study its role in vivo. Zebrafish are able to tolerate severe hemostatic deficiencies that are lethal in mammals. We have generated a targeted genetic deletion in the kringle 1 domain of zebrafish prothrombin. Homozygous mutant embryos develop normally into the mid-juvenile stage but demonstrate complete mortality by 2 months of age primarily due to internal hemorrhage. Mutants are unable to form occlusive venous and arterial thrombi in response to endothelial injury, a defect that was phenocopied using direct oral anticoagulants. Human prothrombin engineered with the equivalent mutation exhibits a severe reduction in secretion, thrombin generation, and fibrinogen cleavage. Together, these data demonstrate the conserved function of thrombin in zebrafish and provide insight into the role of kringle 1 in prothrombin maturation and activity. Understanding how zebrafish are able to develop normally and survive into early adulthood without thrombin activity will provide important insight into its pleiotropic functions as well as the management of patients with bleeding disorders.

Understanding the Impact of Aberrant Splicing in Coagulation Factor V Deficiency

Rare inherited coagulation disorders (RICDs) are congenital deficiencies of the plasma proteins that are involved in blood coagulation, which generally lead to lifelong bleeding manifestations. These diseases are generally qualitative and/or quantitative defects that are associated with monoallelic or biallelic mutations in the relevant gene. Among RICDs, factor V (FV) deficiency is one of the least characterized at the molecular level. Here, we investigated four unrelated patients with reduced plasma FV levels (three severe, one mild), which were associated with a moderately severe bleeding tendency. Sequence analysis of the FV gene identified seven different variants, five hitherto unknown (p.D1669G, c.5789-11C>A, c.5789-12C>A, c.5789-5T>G, and c.6528G>C), and two previously reported (c.158+1G>A and c.5789G>A). The possible pathogenic role of the newly identified missense variant was studied by in silico approaches. The remaining six genetic defects (all putative splicing mutations) were investigated for their possible effects on pre-mRNA splicing by transient transfection experiments in HeLa cells with plasmids expressing appropriate hybrid minigenes. The preparation of minigene constructs was instrumental to demonstrate that the two adjacent variants c.5789-11C>A and c.5789-12C>A are indeed present in cis in the analyzed FV-deficient patient (thus leading to the c.5789-11_12CC>AA mutation). Ex vivo experiments demonstrated that each variant causes either a skipping of the relevant exon or the activation of cryptic splice sites (exonic or intronic), eventually leading to the introduction of a premature termination codon.

Invasive EEG-electrodes in presurgical evaluation of epilepsies: Systematic analysis of implantation-, video-EEG-monitoring- and explantation-related complications, and review of literature

INTRODUCTION

Stereoelectroencephalography (sEEG) is a diagnostic procedure for patients with refractory focal epilepsies that is performed to localize and define the epileptogenic zone. In contrast to grid electrodes, sEEG electrodes are implanted using minimal invasive operation techniques without large craniotomies. Previous studies provided good evidence that sEEG implantation is a safe and effective procedure; however, complications in asymptomatic patients after explantation may be underreported. The aim of this analysis was to systematically analyze clinical and imaging data following implantation and explantation.

RESULTS

We analyzed 18 consecutive patients (mean age: 30.5 years, range: 12-46; 61% female) undergoing invasive presurgical video-EEG monitoring via sEEG electrodes (n = 167 implanted electrodes) over a period of 2.5 years with robot-assisted implantation. There were no neurological deficits reported after implantation or explantation in any of the enrolled patients. Postimplantation imaging showed a minimal subclinical subarachnoid hemorrhage in one patient and further workup revealed a previously unknown factor VII deficiency. No injuries or status epilepticus occurred during video-EEG monitoring. In one patient, a seizure-related asymptomatic cross break of two fixation screws was found and led to revision surgery. Unspecific symptoms like headaches or low-grade fever were present in 10 of 18 (56%) patients during the first days of video-EEG monitoring and were transient. Postexplantation imaging showed asymptomatic and small bleedings close to four electrodes (2.8%).

CONCLUSION

Overall, sEEG is a safe and well-tolerated procedure. Systematic imaging after implantation and explantation helps to identify clinically silent complications of sEEG. In the literature, complication rates of up to 4.4% in sEEG and in 49.9% of subdural EEG are reported; however, systematic imaging after explantation was not performed throughout the studies, which may have led to underreporting of associated complications.

Functional and Molecular Characterization of C91S Mutation in the Second Epidermal Growth Factor-Like Domain of Factor VII

Background

Coagulation Factor VII is a vitamin K-dependent serine protease which has a pivotal role in the initiation of the coagulation cascade. The congenital Factor VII deficiency is a recessive hemorrhagic disorder that occurs due to mutations of F7 gene. In the present study C91S (p.C91S) substitution was detected in a patient with FVII deficiency. This mutation has not been characterized by a functional study.

Objectives

In this study, we aimed to evaluate the impact of C91S substitution on factor VII expression and function.

Materials and Methods

The F7 complete cDNA was isolated from HepG2 cell line and inserted into the pcDNA3.1 mammalian expression vector. The desired mutation was generated by the site-directed mutagenesis and the wild-type and mutated constructs were transfected into CHO-K1 cells. The protein activity and antigen level (antigen concentration) were validated in the culture medium and cell lysate of the transiently transformed cells. An immunocytochemistry procedure was also performed to evaluate the intracellular localization of the mutated and the wild-type FVII, as well.

Results

The present in vitro study has demonstrated that C91S antigen expression was increased in the transfected CHO-K1 cells compared to the wild-type (WT) protein. Despite an increased protein secretion, the factor VII coagulant activity was diminished following C91S substitution when it was assessed by a standard one-stage analysis. In addition, the immunocytochemistry procedure revealed that there was no difference in the intracellular localization of the C91S mutated FVII compared to the WT protein.

Conclusions

Our results present that C91S mutation has an effect on the coagulation activity, secretion, biosynthesis, and probably folding of the FVII leading to the FVII deficiency.

Phenotypical variability in congenital FVII deficiency follows the ISTH-SSC severity classification guidelines: a review with illustrative examples from the clinic

Background

One of the most common rare inherited bleeding disorders, congenital factor VII (FVII) deficiency typically has a milder bleeding phenotype than other rare bleeding disorders. Categorizing severity in terms of factor activity associated with hemophilia (severe <1%, moderate 1%–5%, mild 6%–40%) has led to the observation that bleeding phenotype does not follow closely with FVII activity. Over the past decade, large-scale global registries have investigated bleeding phenotype more thoroughly. The International Society on Thrombosis and Haemostasis has reclassified FVII deficiency as follows: severe, FVII <10%, risk of spontaneous major bleeding; moderate, FVII 10%–20%, risk of mild spontaneous or triggered bleeding; mild, FVII 20%–50%, mostly asymptomatic disease.

Case reports

Eleven illustrative cases of congenital FVII deficiency adapted from clinical practice are described to demonstrate the variability in presentation and in relation to FVII activity levels. Severe FVII deficiency usually presents at a young age and carries the risk of intracranial hemorrhage, hemarthrosis, and other major bleeds. Moderate FVII deficiency tends to present later, often in adolescence and particularly in girls as they reach menarche. Milder disease may not be apparent until found incidentally on preoperative testing, during pregnancy/childbirth, or following unexplained bleeding when faced with hemostatic challenges.

Conclusion

It is important for health care professionals to be aware of the new definitions of severity and typical presentations of congenital FVII deficiency. Failure to appreciate the risks of major bleeding, including intracerebral hemorrhage in those with FVII activity <10%, may put particularly young children at risk.

Homozygous congenital factor VII deficiency with a novel mutation, associated with severe spontaneous intracranial bleeding in a neonate

OBJECTIVE

Herein, a neonate with congenital FVII deficiency is presented.

BASIC METHOD

Diagnosis of congenital FVII deficiency was confirmed by genetic analysis using next-generation sequencing method (MiSeq-Illumina).

RESULT

Our patient was found to have a novel homozygous mutation.

CONCLUSION

Early diagnosis and treatment of congenital FVII deficiency can be crucial.

Rare congenital bleeding disorders

The rare congenital bleeding disorders are a heterogeneous group of diseases which include deficiencies of fibrinogen, prothrombin and factors V, V + VIII, VII, X, XI and XIII. They are usually transmitted as autosomal recessive disorders, and the prevalence of the severe forms ranges from one case in 500,000 for factor VII up to one in 2,000,000 for factor XIII in the general population. Patients with rare congenital bleeding disorders may have a broad spectrum of clinical symptoms, ranging from mucocutaneous bleeding to life-threatening haemorrhages, such as those occurring in the central nervous system. The treatment of these disorders is based principally on the replacement of the deficient factor using, when available, specific plasma-derived or recombinant products. The aim of this narrative review is to summarise current knowledge about these rare bleeding conditions.

Blood coagulation dissected

Hemostasis is the physiological control of bleeding and is initiated by subendothelial exposure. Platelets form the primary vascular seal in three stages (localization, stimulation and aggregation), which are triggered by specific interactions between platelet surface receptors and constituents of the subendothelial matrix. As a secondary hemostatic plug, fibrin clot formation is initiated and feedback-amplified to advance the seal and stabilize platelet aggregates comprising the primary plug. Once blood leakage has been halted, the fibrinolytic pathway is initiated to dissolve the clot and restore normal blood flow. Constitutive and induced anticoagulant and antifibrinolytic pathways create a physiological balance between too much and too little clot production. Hemostatic imbalance is a major burden to global healthcare, resulting in thrombosis or hemorrhage.

Efficacy, safety and pharmacokinetics of a new high-purity factor X concentrate in women and girls with hereditary factor X deficiency

Essentials Plasma-derived factor X concentrate (pdFX) is used to treat hereditary factor X deficiency. pdFX pharmacokinetics, safety and efficacy were assessed in factor X-deficient women/girls. Treatment success rate was 98%; only 6 adverse events in 2 subjects were possibly pdFX related. On-demand pdFX 25 IU kg-1 was effective and safe in women/girls with factor X deficiency.

SUMMARY

Background A high-purity, plasma-derived factor X concentrate (pdFX) has been approved for the treatment of hereditary FX deficiency, an autosomal recessive disorder. Objective To perform post hoc assessments of pdFX pharmacokinetics, safety and efficacy in women and girls with hereditary FX deficiency. Patients/Methods Subjects aged ≥ 12 years with moderate/severe FX deficiency (plasma FX activity of < 5 IU dL-1 ) received on-demand or preventive pdFX (25 IU kg-1 ) for ≤ 2 years. Results Of 16 enrolled subjects, 10 women and girls (aged 14-58 years [median, 25.5 years]) received 267 pdFX infusions. Mean monthly infusions per subject were higher among women and girls (2.48) than among men and boys (1.62). In women and girls, 132 assessable bleeding episodes (61 heavy menstrual bleeds, 47 joint bleeds, 15 muscle bleeds, and nine other bleeds) were treated with pdFX, with a 98% treatment success rate versus 100% in men and boys. Mean pdFX incremental recovery was similar in the two groups (2.05 IU dL-1 versus 1.91 IU dL-1 per IU kg-1 ), as was the mean half-life (29.3 h versus 29.5 h). Of 142 adverse events in women and girls, headache was the most common (12 events in six subjects). Six events (two infusion-site erythema, two fatigue, one back pain, one infusion-site pain) in two subjects were considered to be possibly pdFX-related. Following the trial, pdFX was used to successfully maintain hemostasis in two subjects undergoing obstetric delivery. Conclusions pdFX was well tolerated and effective in women and girls with FX deficiency. Although women and girls had different bleeding symptoms and sites than men and boys, their pdFX pharmacokinetic profile was comparable.