Thrombosis in inherited factor VII deficiency

Acute Thrombotic Events in Association With Coronavirus Disease of 2019 Immunization as Initial Presentation of Congenital Factor VII Deficiency

Coagulation factor VII (FVII) deficiency is a congenital disorder with heterogeneous clinical phenotypes ranging from asymptomatic to life-threatening bleeding and/or thrombotic events. We present the case of an adolescent male who developed acute deep and superficial venous thromboses of the upper extremities in the setting of multiple peripheral venous line insertions and shortly after receiving his second coronavirus disease of 2019 immunization dose. A hemostatic work-up revealed low FVII activity levels associated with 4 different FVII genetic variants. We highlight the need to better understand the pathophysiologic mechanisms behind FVII deficiency-associated prothrombotic risk and the role that specific FVII genetic variants may play in the clinical presentation of these patients.

A case-report of the unprovoked thrombotic event in a patient with thymoma and severe FVII deficiency

BACKGROUND

Factor VII deficiency is a rare bleeding disorder caused by a deficiency of clotting factor VII. However, there have been some case reports of venous thrombosis in patients with factor VII deficiency, especially underlying the prothrombotic risk factors exposure. Patients with factor VII deficiency require special considerations before undergoing surgery to minimize the risk of bleeding or thrombogenesis.

CASE PRESENTATION

Here, we described a patient with early-stage thymoma and severe factor VII deficiency who experienced an unprovoked thrombotic episode before thymectomy and a fatal thrombotic event after surgery. By adopting gene screening, a reported homozygous F7 mutation (p.His408Gln) and a novel heterozygous PROS1 mutation (p.Pro147Ala) were identified. The former resulted in severe factor VII deficiency but did not protect against thrombosis, and the latter was correlated with normal expression and cofactor activities of protein S through the thrombin generation test. The perioperative infusion of recombinant factor VII concentrate and the absence of antithrombotic prophylaxis may collectively contribute to her fatal thrombotic event after surgery.

CONCLUSIONS

For the patients with severe factor VII deficiency undergoing surgery, uniform replacement therapy may not be recommended, and antithrombotic prophylaxis should be used in the case with thrombotic history to minimize the risk of bleeding and thrombogenesis.

A thrombophilic allele of clotting Factor VII/VIIa promoting recurrent pulmonary emboli, clinical details, and a structural model of the altered protein: a case report

BACKGROUND

The clotting or hemostasis system is a meticulously regulated set of enzymatic reactions that occur in the blood and culminate in formation of a fibrin clot. The precisely calibrated signaling system that prevents or initiates clotting originates with the activated Factor Seven (FVIIa) complexed with tissue factor (TF) formed in the endothelium. Here we describe a rare inherited mutation in the FVII gene which is associated with pathological clotting.

CASE PRESENTATION

The 52-year-old patient, with European, Cherokee and African American origins, FS was identified as having low FVII (10%) prior to elective surgery for an umbilical hernia. He was given low doses of NovoSeven (therapeutic Factor VIIa) and had no unusual bleeding or clotting during the surgery. In fact, during his entire clinical course he had no unprovoked bleeding. Bleeding instances occurred with hemostatic stresses such as gastritis, kidney calculus, orthopedic surgery, or tooth extraction, and these were handled without factor replacement. On the other hand, FS sustained two unprovoked and life-threatening instances of pulmonary emboli, although he was not treated with NovoSeven at any time close to the events. Since 2020, he has been placed on a DOAC (Direct Oral Anticoagulant, producing Factor Xa inhibition) and has sustained no further clots.

POSSIBLE MECHANISM OF (UNAUTHORIZED) FVII ACTIVATION

FS has a congenitally mutated FVII/FVIIa gene, which carries a R315W missense mutation in one allele and a mutated start codon (ATG to ACG) in the other allele, thus rendering the patient effectively homozygous for the missense FVII. Structure based comparisons with known crystal structures of TF-VIIa indicate that the patient's missense mutation is predicted to induce a conformational shift of the C170's loop due to crowding of the bulky tryptophan to a distorted "out" position (Fig. 1). This mobile loop likely forms new interactions with activation loop 3, stabilizing a more active conformation of the FVII and FVIIa protein. The mutant form of FVIIa may be better able to interact with TF, displaying a modified serine protease active site with enhanced activity for downstream substrates such as Factor X.

CONCLUSIONS

Factor VII can be considered the gatekeeper of the coagulation system. Here we describe an inherited mutation in which the gatekeeper function is altered. Instead of the expected bleeding manifestations resulting from a clotting factor deficiency, the patient FS suffered clotting episodes. The efficacy of the DOAC in treating and preventing clots in this unusual situation is due to its target site of inhibition (anti-Xa), which lies downstream of the site of action of FVIIa/TF.

Factor VII deficiency in China: Phenotype, genotype and current status of management

Congenital factor VII (FVII) deficiency is a rare bleeding disorder characterised by a wide molecular and clinical heterogeneity. We investigated the clinical phenotype of 193 patients and F7 genotype of 55/193 patients with FVII deficiency throughout China and showed their current status of management. The most frequent bleeding symptoms were epistaxis (44.6%), cutaneous (38.9%), oral cavity (40.4%) bleeding and menorrhagia (44.3% of females of reproductive age). Fatal central nervous system bleeding and disabling joint bleeding occurred in three patients each. The majority of patients (89.6%) had FVII activity (FVII:C) ≤10% and the proportion of symptomatic patients in this group (79.8%) was significantly higher than that in the groups with FVII:C >10%-25% (41.7%) and >25%-50% (37.5%) (χ² = 13.641, p = 0.001). Major bleeds occurred only in patients with FVII:C ≤10%. In total 55 patients underwent genotype analysis: most variants were missense (62.5%) and most patients had homozygous/compound heterozygous (85.4%) variants. Prothrombin complex concentrates (72.4%) were the most frequently used on-demand replacement therapy. Prophylaxis before delivery decreased the risk of postpartum bleeding in women (χ² = 69.243, p = 0.000). Our study provides useful information on the phenotype, genotype and current status of FVII-deficiency patients management and may promote further exploration and care of this population in the future.

Reproductive health and hemostatic issues in women and girls with congenital factor VII deficiency: A systematic review

BACKGROUND

Congenital factor VII (FVII) deficiency is an inherited bleeding disorder, with heterogenous bleeding symptoms. Women with FVII deficiency face hemostatic challenges during menstruation, ovulation, and childbirth. This systematic review evaluated prevalence and management of bleeding symptoms associated with gynecological and obstetric issues in women with FVII deficiency.

METHODS

Databases (BIOSIS Previews, Current Contents Search, Embase, and MEDLINE) were searched for studies reporting FVII deficiency and gynecological or obstetric issues in women. Articles were screened using Joanna Briggs Institute checklists and relevant data extracted.

RESULTS

One hundred fourteen women were identified from 62 publications. Forty-six women had severe deficiency (FVII:C < 5% or <5 IU/dl). Heavy menstrual bleeding (HMB) was the most common bleeding symptom (n = 94; 82%); hospitalization and urgent medical/surgical interventions for acute HMB episodes were required in 16 women (14%). Seven women reported ovarian bleeding (6%); other bleeding symptoms varied. Patient management was inconsistent and included hemostatic and hormonal treatments. Only four women (7%) reporting vaginal bleeding during pregnancy. Postpartum hemorrhage (PPH) occurred following 12/45 deliveries (27%; 5 [42%] requiring blood transfusion) and was not necessarily prevented by prophylaxis (8 women).

CONCLUSION

Women with congenital FVII deficiency have an increased risk of HMB, ovarian bleeding, and PPH, impacting quality of life. Recognition of a bleeding disorder as the cause is often delayed. Management of bleeding complications is heterogeneous due to lack of treatment guidelines. Harmonizing severity classification of FVII deficiency may help standardize treatment strategies and development of specific guidelines for these women.

Extensive genetic screening of Iranian Factor FVII-deficient individuals unraveled several novel mutations and postulated founder effects in some cases

Background

As the most frequent congenital rare bleeding disorder that transmits in an autosomal recessive manner, factor VII (FVII) deficiency is a serious bleeding complication in populations with high rate of in-marriages. While diagnosis mainly relies on clinical and laboratory phenotypes, plasma FVII antigen and activity levels do not often correlate with symptoms' severity.

Objectives

Genetic profiling of the affected individuals potentially improves our biological understanding of this complicated rare disorder.

Methods

Conventional polymerase chain reaction-Sanger sequencing and whole-exome sequencing were applied for genetic profiling of F7 gene in 66 symptomatic FVII-deficient individuals from 62 independent pedigrees. Thirty-nine asymptomatic relatives of the patients were also studied.

Results

Thirty different F7 pathogenic variations were identified in the studied cases of which 11 have not been reported before. The novel mutations include 5 missenses (c.715G>A, c.794T>C, c.1090C>G, c.1222C>A, c.1265T>C), 3 splicing (c.316+1G>T, c.682-2A>G, c.572-16C>G), 2 nonsenses (c.790delC, c.1248G>A), and 1 frameshift (c.1346delA). A founder effect is proposed for c.790delC that was detected in 8 independent pedigrees who were all from similar geographical regions and ethnic backgrounds. Homozygous c.790delC reduces plasma FVII activity to <1% and causes spontaneous intracranial hemorrhage in early infancy.

Conclusion

From the 66 studied symptomatic FVII-deficient individuals, 58 were homozygous carriers of the identified variations. Identification of homozygotes clarifies the potential role of nucleotide variations in reducing FVII activity and their contributions to a certain phenotype. Some of those variations, such as c.1A>G, c.509G>A, c.634C>T, and c.1285G>A have only been previously reported as heterozygous.

Thromboelastometry as an Ancillary Tool for Evaluation of Coagulation Status after rFVIIa Therapy in a Pregnant Woman with Severe Hypoproconvertinemia-A Case Series and Review of the Literature

Introduction: Factor VII (FVII) deficiency is a rare hemorrhagic diathesis. In females, heavy menstrual and postpartum bleeding can appear as a consequence of its deficiency. Supplementation of the recombinant FVIIa is widely accepted. The supplementation effect in FVII-deficient subjects is difficult to predict, and severe hemorrhage has been described even when FVII levels after supplementation were within normal ranges. The aim of this report is to present the application of thromboelastometry to control the coagulation status in a patient with severe FVII deficiency during pregnancy and delivery, supplemented by rFVIIa per protocol complicated with life-threatening venous thromboembolism. Methods: Rotational thromboelastometry (ROTEM) was performed in 16 pregnant women: in one 28 year old primigravida at 35 weeks of pregnancy with congenital FVII deficiency after rFVIIa administration and 15 healthy women at 38 gestational weeks. The results were compared. Results: The thromboelastometry results showed significant shortening of the clotting time in the extrinsic and the intrinsic pathway in the hypoproconvertinemia patient after rFVIIa administration in relation to healthy pregnant women. A significant reduction in maximum lysis of the clot after FVII supplementation was observed. Conclusions: The thromboelastometry results showed a significant hypercoagulable state with hypoproconvertinemia. Thrombotic complications after delivery might be prevented by the reduction in rFVIIa guided by thromboelastometry. Thromboelastometry performed on a pregnant woman with factor VII deficiency during the supplementation of rFVIIa in peripartum time might be helpful in order to determine an individual, effective dosage regimen of rFVIIa to ensure full correction of clotting disorders without the tendency to develop thrombosis, but further studies are needed.

Changes in Procoagulant Blood Biomarkers After Mechanical Thrombectomy

OBJECTIVES

There is limited knowledge of the relationship between mechanical thrombectomy (MT) and endothelial inflammation in large-vessel occlusion (LVO) acute ischemic stroke (AIS). Intimal arterial damage releases tissue factor, a precipitant of the clotting cascade and thrombosis. We report changes in blood coagulation markers after MT treated with and without tissue plasminogen activator for AIS.

MATERIALS AND METHODS

Cases of LVO-AIS treated with MT were included. Blood coagulation marker levels were measured within 10 h of stroke onset as a baseline and then 48 h later. Assayed biomarkers included: tissue factor procoagulant activity (TFPCA), factor VII (FVII), activated factor VII (FVIIa), factor VIII (FVIII), d-dimer, thrombin-antithrombin complex (TAT), plasminogen activator inhibitor-1 (PAI-1), and tissue factor pathway inhibitor (TFPI). Biomarker levels of MT with tissue plasminogen activator (TPA) or without (non-TPA) are reported.

RESULTS

Biomarker levels from five patients with LVO-AIS treated with MT (three non-TPA, two TPA) were included. In non-TPA cases, TFPCA and PAI-1 increased while FVII, FVIIa, TAT, d-dimer, and TFPI decreased from baseline to 48 h. In TPA cases, TFPCA, FVIIa, d-dimer, TFPI, and PAI-1 decreased while FVIII increased from baseline to 48 h.

CONCLUSIONS

TFPCA increased after MT in non-TPA but decreased in TPA treated patients. This finding suggests that MT is associated with elevated inflammation and procoagulation which may be reduced with TPA treatment. With further validation, the increase in TFPCA levels could help guide anticoagulant management of patients with MT without TPA.

Accidentally discovered high INR in pregnancy unmasks an inherited factor VII (FVII) deficiency that is paradoxically associated with thrombotic tendency

A 32-year-old multiparous obese woman was referred to our center at 37 weeks of twin gestation. She was referred for birth planning following an accidentally discovered high international normalised ratio (INR) in routine preoperative labs. Her history was significant for recurrent pregnancy-associated deep venous thrombosis as well as two early pregnancy losses. Further work-up revealed transaminitis, mild splenomegaly and high lupus anticoagulant titre. A multidisciplinary team of physicians from the high-risk pregnancy, anaesthesiology, haematology, gastroenterology and hepatology departments put a management plan; it culminated into uncomplicated delivery of the patient by repeated caesarian section. The team was also able to figure out the cause of the patient's high INR that is associated with thrombophilia rather than haemophilia.

Biochemical, molecular and clinical aspects of coagulation factor VII and its role in hemostasis and thrombosis

Activated factor VII (FVIIa), the first protease of clotting, expresses its physiological procoagulant potential only after complexing with tissue factor (TF) exposed to blood. Deep knowledge of the FVIIa-TF complex and F7 gene helps to understand the Janus-faced clinical findings associated to low or elevated FVII activity (FVIIc). Congenital FVII deficiency, the most frequent among the recessively inherited bleeding disorders, is caused by heterogeneous mutations in the F7 gene. Complete FVII deficiency causes perinatal lethality. A wide range of bleeding symptoms, from life-threatening intracranial hemorrhage to mild mucosal bleeding, is observed in patients with apparently modest differences in FVIIc levels. Though clinically relevant FVIIc threshold levels are still uncertain, effective management, including prophylaxis, has been devised, substantially improving the quality of life of patients. The exposure of TF in diseased arteries fostered investigation on the role of FVII in cardiovascular disease. FVIIc levels were found to be predictors of cardiovascular death and to be markedly associated to F7 gene variation. These genotype-phenotype relationships are among the most extensively investigated in humans. Genome-wide analyses extended association to numerous loci that, together with F7, explain >50% of FVII level plasma variance. However, the ability of F7 variation to predict thrombosis was not consistently evidenced in the numerous population studies. Main aims of this review are to highlight i) the biological and clinical information that distinguishes FVII deficiency from the other clotting disorders and ii) the impact exerted by genetically predicted FVII level variation on bleeding as well as on the thrombotic states.

Evaluation of the Antihemostatic and Antithrombotic Effects of Lowering Coagulation Factor VII Levels in a Non-human Primate

Introduction

Tissue factor (TF) and factor (F) VII, components of the extrinsic pathway of blood coagulation, are essential for hemostatic plug formation in response to injury; less clear are their roles in propagating thrombosis, as observational data in humans with congenital FVII deficiency suggests persistent thrombotic and bleeding risk even at significantly decreased FVII levels. We aimed to define the contribution of FVII to thrombus formation and hemostasis using a non-human primate model.

Methods

We treated baboons with a FVII antisense oligonucleotide (ASO) and measured platelet and fibrin deposition inside and distal to collagen- or TF-coated vascular grafts. We assessed hemostasis by measuring bleeding time (BT) and prothrombin time (PT). Enoxaparin and vehicle treatments served as controls.

Results

FVII-ASO treatment reduced FVII levels by 95% and significantly increased both the PT and BT. Lowering FVII levels did not decrease platelet deposition in collagen- or TF-coated grafts, in thrombi distal to the grafts, or fibrin content of either collagen- and TF-coated grafts. Lowering FVII levels were associated with a modest 25% reduction in platelet deposition at 60 min in the distal thrombus tail of TF-coated grafts only.

Conclusions

FVII inhibition by way of ASO is feasible yet significantly impairs hemostasis while only exhibiting antithrombotic effects when thrombosis is initiated by vessel wall surface-associated TF exposure.

Unprovoked Pulmonary Embolism in Factor VII Deficiency

Thrombotic events in bleeding disorders such as hemophilia A or B, Von Willebrand disease, afibrinogenemia, factor VII deficiency, and factor XI deficiency are rare but have been reported. These events usually occur in the presence of prothrombotic risk factors such as recent surgery, trauma, or factor replacement therapy. We present a case of a 68-year-old Hispanic female with a history of factor VII deficiency who presented with shortness of breath, chest pain, and palpitations and was found to have pulmonary embolism. Our patient did not have any of the above-mentioned thrombotic risk factors. Our case and review of the literature show that factor VII deficiency does not provide protection against thrombosis.

Spontaneous chronic subdural hematoma in young adult: the role of missing coagulation facto

AIM

Chronic subdural hematoma (CSDH) is typically in elderly and rarely in young people. To prevent complications and re-bleeding after surgical treatment of CSDH it is important to assess the risk factors as coagulation disorders especially in young patients (below 65 years) with no history of head trauma, alcohol abuse or anticoagulant therapy.

PATIENTS AND METHODS

This study consists of 16 patients (12 males, 4 females) with age ranging from 27 to 59 years (median 48,25 years) operated for CSDH. All patients are submitted to routine coagulation parameters pre-operatively and complete screening for unknown coagulation deficit in the follow-up.

RESULTS

Factor VII was altered in 6 out of 16 patients and one patient had the alteration of the Von Willebrand factor. Recurrence occurred in 4 out of 16 patients and all of these patients were positive for factor VII deficiency. Three pts were in therapy with ASA. No patients were alcoholists or suffered from hematological disease.

CONCLUSION

In this study we documented that the decreased activity of VII factor may play a role in the pathophysiology and recurrence of spontaneous CSDH in young adults. We suggest that for young patients aged under 65 y.o. suffered from CSDH the screening of coagulation factors is useful to planning a safely and correct surgical therapy.

Molecular Mechanisms and Determinants of Innovative Correction Approaches in Coagulation Factor Deficiencies

Molecular strategies tailored to promote/correct the expression and/or processing of defective coagulation factors would represent innovative therapeutic approaches beyond standard substitutive therapy. Here, we focus on the molecular mechanisms and determinants underlying innovative approaches acting at DNA, mRNA and protein levels in inherited coagulation factor deficiencies, and in particular on: (i) gene editing approaches, which have permitted intervention at the DNA level through the specific recognition, cleavage, repair/correction or activation of target sequences, even in mutated gene contexts; (ii) the rescue of altered pre-mRNA processing through the engineering of key spliceosome components able to promote correct exon recognition and, in turn, the synthesis and secretion of functional factors, as well as the effects on the splicing of missense changes affecting exonic splicing elements; this section includes antisense oligonucleotide- or siRNA-mediated approaches to down-regulate target genes; (iii) the rescue of protein synthesis/function through the induction of ribosome readthrough targeting nonsense variants or the correction of folding defects caused by amino acid substitutions. Overall, these approaches have shown the ability to rescue the expression and/or function of potentially therapeutic levels of coagulation factors in different disease models, thus supporting further studies in the future aimed at evaluating the clinical translatability of these new strategies.

Thrombotic Events in Homozygotes with a Proven or Highly Probable Arg304Gln Factor VII Mutation (FVII Padua)1): Only Limited Replacement Therapy is Needed in Case of Surgery

OBJECTIVE

To investigate the prevalence of thrombotic events among patients with proven or highly probable homozygosis for the Arg304Gln (Factor VII Padua) defect or compound heterozygosis containing the Arg304Gln mutation.

METHODS

Homozygotes and compound heterozygotes proven by molecular studies to have the Arg304Gln mutation were gathered from personal files and from two PubMed searches. In addition, patients with probable homozygosis on the basis of clotting tests (discrepancies among Factor VII activity levels according to the tissue thromboplastin used) were also gathered.

RESULTS

30 proven homozygotes and 17 probable ones were gathered together with 8 compound heterozygotes. In the latter use, the associated mutation was Cys135Arg (twice), Gly180Arg, Arg304Trp, Arg315Trp, His348Gln, Gly365Cys. The prevalence of venous thrombotic events was 16.6, 11.8 and 11.1 percent, respectively for the three groups of patients. Heterozygotes showed no thrombotic event. The difference for proven homozygotes was statistically significant, while for the other groups only a trend was present.

CONCLUSION

proven homozygous or compound heterozygous patients with the Arg304Gln mutation showed a higher than expected incidence of thrombotic events. The same is true for probable cases gathered only on the basis of clotting tests. These patients, because of their frequent lack of bleeding and for their relatively high prevalence of thrombosis should probably receive only limited replacement therapy in case of surgical procedures.

Takayasu Arteritis Presenting as Renovascular Hypertension and Renal Failure in a Patient with Factor VII Deficiency

A 23-year-old female patient with factor VII (FVII) deficiency was admitted with severe hypertension and renal failure. Brachial arterial pressures were 230/120 and 220/115 mm/Hg on the right and left arms, respectively. There was no blood pressure difference between the arms. Renal artery Doppler ultrasonography revealed bilateral severe renal artery stenosis (RAS). Contrast-enhanced magnetic resonance imaging angiography (CE-MRA) revealed severe mural irregularities, contrast enhancement in the aorta and its branches, and long-segment stenosis starting in the abdominal aorta and extending into the proximal renal arteries. The diagnosis of Takayasu arteritis (TA) complicated by RAS in a patient with FVII deficiency was established. This is the first case of concomitant TA and factor VII deficiency in the literature. In conclusion, TA complicated with RAS should be kept in mind in the etiology of secondary hypertension, even when there is no blood pressure difference between the arms in patients. CE-MRA is an accurate, sensitive, and safe imaging method for diagnosing vasculitis, even in the early phases of the disease, and should be considered for evaluating the activity and response to treatment in patients with TA.

Bleeding symptoms at disease presentation and prediction of ensuing bleeding in inherited FVII deficiency

Individuals with inherited factor VII (FVII) deficiency display bleeding phenotypes ranging from mild to severe, with 30% of patients having always been asymptomatic (non-bleeding). In 626 FVII-deficient individuals, by analysing data from the International Factor VII (IF7) Registry and the Seven Treatment Evaluation Registry (STER), we determined whether bleeding type at disease presentation and FVII coagulant activity (FVIIc) predict ensuing bleeds. At disease presentation/diagnosis, 272 (43.5%) individuals were non-bleeding, 277 (44.2%) had minor bleeds, and 77 (12.3%) had major bleeds. During a median nine-year index period (IP) observation, 87.9% of non-bleeding individuals at presentation remained asymptomatic, 75.1% of minor-bleeders had new minor bleeds, and 83.1% of major-bleeders experienced new major bleeds. After adjusting for FVIIc levels and other clinical and demographic variables, the relative risk (RR) for ensuing bleedings during the IP was 6.02 (p <0.001) and 5.87 (p <0.001) in individuals presenting with major and minor bleeds, respectively. Conversely, compared to non-bleeding individuals, a 10.95 (p = 0.001) and 28.21 (p <0.001) RR for major bleedings during the IP was found in those with minor and with major bleeds at presentation, respectively. In conclusion, in FVII deficiency, the first major bleeding symptom is an independent predictor of the risk of subsequent major bleeds.

Factor VII deficiency: a novel missense variant and genotype-phenotype correlation in patients from Southern Italy

This study aimed at attempting to correlate genotype and phenotype in factor VII deficiency. Here, we present molecular and clinical findings of 10 patients with factor VII deficiency. From 2013 to 2016, 10 subjects were referred to our center because of a prolonged prothrombin time identified during routine or presurgery examinations or after a laboratory assessment of a bleeding episode. Mutation characterization was performed using the bioinformatics applications PROMO, SIFT, and Polyphen-2. Structural changes in the factor VII protein were analyzed using the SPDB viewer tool. Of the 10 variants we identified, 1 was responsible for a novel missense change (c.1199G>C, p.Cys400Ser); in 2 cases we identified the c.-54G>A and c.509G>A (p.Arg170His) polymorphic variants in the 5′-upstream region of the factor VII gene and exon 6, respectively. To our knowledge, neither of these polymorphic variants has been described previously in factor VII-deficient patients. In silico predictions showed differences in binding sites for transcription factors caused by the c.-54G>A variant and a probable damaging effect of the p.Cys400Ser missense change on factor VII active conformation, leading to breaking of the Cys400-Cys428 disulfide bridge. Our findings further suggest that, independently of factor VII levels and of variants potentially affecting factor VII levels, environmental factors, e.g., trauma, could heavily influence the clinical phenotype of factor VII-deficient patients.

Coronary artery stenosis treatment in aging patients with inherited Factor VII deficiency: Where do we stand?

Aging with rare bleeding disorders such as factor VII (FVII) deficiency poses several challenges to treatment because of the occurrence of cerebral and cardiovascular age-related comorbidities and high bleeding risks. We report a case of long-term treatment with antiplatelet agents and contemporary prophylaxis of bleeding in a woman affected by severe FVII deficiency diagnosed with symptomatic coronary artery stenosis. Information on the management of antithrombotic treatment in rare bleeding disorders is lacking and mainly limited to anecdotal reports or side effects secondary to replacement therapy. We also briefly reviewed available data on the treatment of arterial thrombosis in FVII deficiency.

Dietary reference values for vitamin K

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives dietary reference values (DRVs) for vitamin K. In this Opinion, the Panel considers vitamin K to comprise both phylloquinone and menaquinones. The Panel considers that none of the biomarkers of vitamin K intake or status is suitable by itself to derive DRVs for vitamin K. Several health outcomes possibly associated with vitamin K intake were also considered but data could not be used to establish DRVs. The Panel considers that average requirements and population reference intakes for vitamin K cannot be derived for adults, infants and children, and therefore sets adequate intakes (AIs). The Panel considers that available evidence on occurrence, absorption, function and content in the body or organs of menaquinones is insufficient, and, therefore, sets AIs for phylloquinone only. Having assessed additional evidence available since 1993 in particular related to biomarkers, intake data and the factorial approach, which all are associated with considerable uncertainties, the Panel maintains the reference value proposed by the Scientific Committee for Food (SCF) in 1993. An AI of 1 μg phylloquinone/kg body weight per day is set for all age and sex population groups. Considering the respective reference body weights, AIs for phylloquinone are set at 70 μg/day for all adults including pregnant and lactating women, at 10 μg/day for infants aged 7-11 months, and between 12 μg/day for children aged 1-3 years and 65 μg/day for children aged 15-17 years.

Diagnosis and Treatment of von Willebrand Disease and Rare Bleeding Disorders

Along with haemophilia A and B, von Willebrand disease (VWD) and rare bleeding disorders (RBDs) cover all inherited bleeding disorders of coagulation. Bleeding tendency, which can range from extremely severe to mild, is the common symptom. VWD, due to a deficiency and/or abnormality of von Willebrand factor (VWF), represents the most frequent bleeding disorder, mostly inherited as an autosomal dominant trait. The diagnosis may be difficult, based on a bleeding history and different diagnostic assays, which evaluate the pleiotropic functions of VWF. Different treatment options are available for optimal management of bleeding and their prevention, and long-term outcomes are generally good. RBDs are autosomal recessive disorders caused by a deficiency of any other clotting factor, apart from factor XII, and cover roughly 5% of all bleeding disorders. The prevalence of the severe forms can range from 1 case in 500,000 up to 1 in 2–3 million, according to the defect. Diagnosis is based on bleeding history, coagulation screening tests and specific factor assays. A crucial problem in RBDs diagnosis is represented by the non-linear relationship between clinical bleeding severity and residual clotting levels; genetic diagnosis may help in understanding the phenotype. Replacement therapies are differently available for patients with RBDs, allowing the successful treatment of the vast majority of bleeding symptoms.

Thrombosis in a bleeding disorder: case of thromboembolism in factor VII deficiency

Congenital factor VII deficiency (FVIID) is a rare disorder with a wide range of bleeding manifestations. The disorder does not protect patients against occurrence of thrombosis, and deep vein thrombosis can occur in the setting of surgery and recombinant factor VIIa replacement.

Ischemic stroke in a patient with moderate to severe inherited factor VII deficiency

Thrombosis is known to occur in patients with rare inherited bleeding disorders, usually in the presence of a thrombotic risk factor such as surgery and/or factor replacement therapy, but sometimes spontaneously. We present the case of a 72-year-old African American male diagnosed with congenital factor VII (FVII) deficiency after presenting with ischemic stroke, presumably embolic, in the setting of atherosclerotic carotid artery stenosis. The patient had an international normalized ratio (INR) of 2.0 at presentation, with FVII activity of 6% and normal Extem clotting time in rotational thromboelastometry. He was treated with aspirin (325 mg daily) and clopidogrel (75 mg daily) with no additional bleeding or thrombotic complications throughout his admission. This case provides further evidence that moderate to severe FVII deficiency does not protect against thrombosis.

Rare bleeding disorders: diagnosis and treatment

Despite the worldwide prevalence of rare bleeding disorders (RBDs), knowledge of these conditions and their management is suboptimal; health care professionals often have little diagnostic and treatment experience with variable access to diagnostic modalities required for accurate identification. Therefore, patients often experience morbidity and mortality due to delayed diagnosis. As RBDs represent a small potential commercial market, few, if any, specific therapies exist for these conditions. As a result, affected individuals commonly face delayed diagnosis, incomplete laboratory evaluation, and limited treatment options. Standardization and customization of coagulation assays, full genome sequencing, and global clotting assays will significantly improve diagnosis of patients with RBDs. In addition, new therapeutic modalities, both recombinant and plasma derived, are emerging, at least in developed countries. Registries and clinical trials have demonstrated decreased bleeding and improved outcomes when patients are appropriately diagnosed and properly treated. Expansion and harmonization of international registries has been initiated to correlate genotype, laboratory, and clinical phenotypes including bleeding severity to improve the diagnosis and therapeutic approach. This review focuses on the latest advances in our understanding, diagnosis, and treatment of RBDs.

Pathogenetic role of Factor VII deficiency and thrombosis in cross-reactive material positive patients

Congenital Factor VII (FVII) deficiency can be divided into two groups: cases of "true" deficiency, or cross-reactive material (CRM) negative and variants that are cross-reactive material positive.The first form is commonly recognized as Type I condition whereas the second one is known as Type II. FVII deficiency has been occasionally associated with thrombotic events, mainly venous. The reasons underlying this peculiar manifestation are unknown even though in the majority of associated patients thrombotic risk factors are present. The purpose of the present study was to investigate if a thrombotic event was more frequent in Type I or in Type II defect.The majority of patients with FVII deficiency and thrombosis belong to Type II defects. In the following paper we discuss the possible role of the dysfunctional FVII cross-reaction material as a contributory cause for the occurrence of thrombosis.

Recombinant factor VIIa treatment for asymptomatic factor VII deficient patients going through major surgery

Factor VII deficiency is the most common among the rare autosomal recessive coagulation disorders worldwide. In factor VII deficient patients, the severity and clinical manifestations cannot be reliably determined by factor VII levels. Severe bleeding tends to occur in individuals with factor VII activity levels of 2% or less of normal. Patients with 2-10% factor VII vary between asymptomatic to severe life threatening haemorrhages behaviour. Recombinant factor VIIa (rFVIIa) is the most common replacement therapy for congenital factor VII deficiency. However, unlike haemophilia patients for whom treatment protocols are straight forward, in asymptomatic factor VII deficiency patients it is still debatable. In this study, we demonstrate that a single and very low dose of recombinant factor VIIa enabled asymptomatic patients with factor VII deficiency to go through major surgery safely. This suggestion was also supported by thrombin generation, as well as by thromboelastometry.

Prophylaxis in congenital factor VII deficiency: indications, efficacy and safety. Results from the Seven Treatment Evaluation Registry (STER)

Because of the very short half-life of factor VII, prophylaxis in factor VII deficiency is considered a difficult endeavor. The clinical efficacy and safety of prophylactic regimens, and indications for their use, were evaluated in factor VII-deficient patients in the Seven Treatment Evaluation Registry. Prophylaxis data (38 courses) were analyzed from 34 patients with severe factor VII deficiency (<1-45 years of age, 21 female). Severest phenotypes (central nervous system, gastrointestinal, joint bleeding episodes) were highly prevalent. Twenty-one patients received recombinant activated factor VII (24 courses), four received plasma-derived factor VII, and ten received fresh frozen plasma. Prophylactic schedules clustered into "frequent" courses (three times weekly, n=23) and "infrequent" courses (≤ 2 times weekly, n=15). Excluding courses for menorrhagia, "frequent" and "infrequent" courses produced 18/23 (78%) and 5/12 (41%) "excellent" outcomes, respectively; relative risk, 1.88; 95% confidence interval, 0.93-3.79; P=0.079. Long term prophylaxis lasted from 1 to >10 years. No thrombosis or new inhibitors occurred. In conclusion, a subset of patients with factor VII deficiency needed prophylaxis because of severe bleeding. Recombinant activated factor VII schedules based on "frequent" administrations (three times weekly) and a 90 μg/kg total weekly dose were effective. These data provide a rationale for long-term, safe prophylaxis in factor VII deficiency.

Surgery in patients with congenital factor VII deficiency: A single center experience

Background

Congenital factor VII (FVII) deficiency is a rare hemorrhagic disorder that can cause excessive bleeding during and after surgery in affected patients. The recombinant form of activated factor VII (rFVIIa, NovoSeven® from Novo Nordisk, Bagsvaerd, Denmark), which was developed as a second-generation bypassing agent, has recently been used in the management of bleeding for patients with congenital FVII deficiency.

Methods

We reviewed the results of 8 surgical procedures in 5 patients with congenital FVII deficiency at the Kyung Hee University Hospital, Gangdong, Seoul, Korea, between January 2008 and June 2010. We administrated rFVIIa preoperatively in six patients and postoperatively in five patients.

Results

Between January 2008 and June 2010 at our center, 8 operations were performed successfully and no complications were observed in the 5 patients with congenital FVII deficiency. The median level of FVII activity was 2% (range, 0.6-7%). Four orthopedic procedures, 1 tonsillectomy, and 3 dental extractions were performed. The median duration of hospitalization was 8.5 days (range, 0-15 days). rFVIIa was administered at all procedures, except the dental extraction that was performed using only antifibrinolytic agents without any replacement. No bleeding or thrombogenic complications were observed in any case.

Conclusion

Patients with congenital FVII deficiency who require surgery can be treated efficiently and safely with rFVIIa or antifibrinolytic agents. rFVIIa was well tolerated and maintained effective hemostasis and showed good clinical outcome after the major surgery.

Considerations on a tentative classification of FVII deficiency suited for practical clinical purposes

Adequate classifications of disorders are of paramount importance in the management of congenital bleeding disorders. Classification of congenital FVII deficiency should be simple, based on few tests using thromboplastins of different origin. The first thromboplastin to be used is a rabbit brain preparation since it has been proven that this is the one that, overall, yields the lowest activity level. This is particularly so since molecular biology techniques have supplied important information with regard to the structure-function relation but have failed to supply a satisfactory classification of the defect. Mutations in the same domain have yielded different forms of FVII deficiency. Furthermore, molecular biology techniques are time consuming and are not feasible in every laboratory. A classification of FVII deficiency based on clinical, clotting, and immunological assays is proposed. This classification is suited for practical clinical purposes and may represent a useful preparatory basis for molecular biology studies.

rFVIIa administered by continuous infusion during surgery in patients with severe congenital FVII deficiency

The use of recombinant FVIIa (rFVIIa) to control bleed in individuals with FVII deficiency has been proven to be effective. The main problems associated with its use are that it requires frequent bolus injections to counteract its short half-life and high cost. Our study aimed to evaluate whether any advantage could be gained by providing rFVIIa by continuous infusion during surgery with regard to haemostatic efficacy, safety and cost. The prospective study included 10 patients with severe FVII deficiency, who underwent 25 surgical procedures (13 major and 12 minor procedures) and were treated with rFVIIa administered by continuous infusion. Tranexamic acid was given concomitantly every 8 h. Prothrombin time, FVII:C assay and thrombin generation assay were used to monitor the treatment. The mean total dose given was 10 mg during a major surgery and 4.4 mg during a minor surgery for a mean treatment duration of 7.5 and 4.0 days respectively. This corresponds to a reduction of 70-90% in drug usage and medication cost compared with bolus injections. Except for one major perioperative bleeding, excellent haemostasis was achieved in all procedures. One patient developed a transient inhibitory activity. None of these events affected the postoperative course or prolonged the hospital stay. Our study demonstrated that continuous infusion of rFVIIa during surgery is safe, effective and highly cost effective.

Delineating the Hemostaseome as an aid to individualize the analysis of the hereditary basis of thrombotic and bleeding disorders

Next-generation sequencing and genome-wide association studies represent powerful tools to identify genetic variants that confer disease risk within populations. On their own, however, they cannot provide insight into how these variants contribute to individual risk for diseases that exhibit complex inheritance, or alternatively confer health in a given individual. Even in the case of well-characterized variants that confer a significant disease risk, more healthy individuals carry the variant, with no apparent ill effect, than those who manifest disease. Access to low-cost genome sequence data promises to provide an unprecedentedly detailed view of the nature of the hereditary component of complex diseases, but requires the large-scale comparison of sequence data from individuals with and without disease to deliver a clinical calibration. The provision of informatics support remains problematic as there are currently no means to interpret the data generated. Here, we initiate this process, a prerequisite for such a study, by narrowing the focus from an entire genome to that of a single biological system. To this end, we examine the 'Hemostaseome,' and more specifically focus on DNA sequence changes pertaining to those human genes known to impact upon hemostasis and thrombosis that can be analyzed coordinately, and on an individual basis, to interrogate how specific combinations of variants act to confer disease predisposition. As a first step, we delineate known members of the Hemostaseome and explore the nature of the genetic variants that may cause disease in individuals whose hemostatic balance has become shifted toward either a prothrombotic or anticoagulant phenotype.