The effect of factor XIa on thrombin and plasmin generation, clot formation, lysis and density in coagulation factors deficiencies

INTRODUCTION

Growing evidence supports the importance of factor (F) XI activation for thrombosis and hemostasis as well as inflammation and complement systems. In this study, we evaluated the effect of activated FXI (FXIa) on the detection of factor deficiencies by global hemostasis assays of thrombin generation (TG), plasmin generation (PG), and clot formation and lysis (CFL).

MATERIALS AND METHODS

An absorbance and fluorescence microplate assay was used to simultaneously observe TG, PG, and CFL in FV-, FVII-, FVIII-, and FIX-deficient plasmas supplemented with purified factors. Coagulation was initiated with tissue factor with or without FXIa in the presence of tissue plasminogen activator. Thrombin and plasmin peak heights (TPH and PPH), maximal clot density (MCD), times to clotting (CT), thrombin and plasmin peaks (TPT and PPT) and clot lysis (LyT) and a new parameter, clot lifetime (LiT), were evaluated.

RESULTS

TG/CFL were elevated by the FXIa at low FV (below 0.1 IU/mL), and at FVIII and FIX above 0.01 IU/mL. FXIa affected PG only at low FV and FVII. At high factor concentrations, FXIa reduced MCD. Thrombin and plasmin substrates had effect on CT, LyT, LiT and MCD parameters.

CONCLUSIONS

FXIa reveals new relationships between TG, PG and CFL parameters in factor deficiencies suggesting potential benefits for discrimination of bleeding phenotypes.

Acquired factor VII deficiency in pediatric inflammatory bowel disease: Report of three cases

Bleeding disorders can exacerbate gastrointestinal bleeding in inflammatory bowel disease (IBD) at the time of diagnosis or flares. Factor VII (FVII) deficiency is a life-threatening rare congenital bleeding disorder in childhood. This study describes three adolescent patients with IBD accompanied by acquired FVII deficiency. This is the first case series of patients with IBD accompanied by FVII deficiency. We hypothesized that inflammation, accelerated consumption, disease severity, and weight loss can cause decreased FVII activity in patients diagnosed with IBD. To control intestinal bleeding, we must keep in mind factor deficiencies in IBD.

Current status and future prospects of activated recombinant coagulation factor VIIa, NovoSeven®, in the treatment of haemophilia and rare bleeding disorders

rFVIIa, a human recombinant activated coagulation factor VII, has been used worldwide for more than two decades for the treatment of bleeding episodes and prevention of bleeding in patients undergoing surgery/invasive procedures with congenital haemophilia A or B with inhibitors (CHwI A or B), acquired haemophilia (AH), congenital factor VII deficiency and Glanzmann thrombasthenia (GT), refractory to platelet transfusion. The approved dosage, administration and indication of rFVIIa in the US, Europe and Japan differ, depending on the needs of the patient population and regulatory practices. This review presents an overview of the current status and future prospects, including that from a Japanese perspective, of using rFVIIa in the treatment of approved indications. The efficacy and safety of rFVIIa in the approved indications has been demonstrated in several randomised and observational studies and data from registries. The overall incidence of thrombosis across all approved indications in a retrospective safety assessment of clinical trials and registries, prelicensure studies and postmarketing surveillance studies of rFVIIa use was 0.17%. Specifically, the risk of thrombotic events was 0.11% for CHwI, 1.77% for AH, 0.82% for congenital factor VII deficiency and 0.19% for GT. Emerging non-factor therapies such as emicizumab have changed the treatment landscape of haemophilia A, including preventing bleeding in patients with CHwI. However, rFVIIa will continue to play a significant role in the treatment of such patients, particularly during breakthrough bleeding or surgical procedures.

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.

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.

Acquired Factor VII Deficiency Associated With Chronic Myeloid Leukemia Blast Crisis

Factor VII (FVII) is an important, vitamin K-dependent clotting factor. Acquired FVII deficiency is a rare entity that is associated with serious bleeding complications. We report a case of acquired FVII deficiency in a patient with recurrent chronic myeloid leukemia in blast crisis who developed bilateral retinal hemorrhages. The coagulopathy was corrected with the initiation of chemotherapy and subsequent reduction in peripheral blast count.

High Prevalence of Congenital Factor VII (FVII) Deficiency in Adolescent Females with Heavy Menstrual Bleeding and Iron Deficiency Anemia

STUDY OBJECTIVE

To examine the clinical characteristics and prevalence of congenital bleeding disorders (CBDs), with emphasis on congenital factor VII (FVII) deficiency and other rare bleeding disorders, in adolescent and young adult females referred to a hemophilia treatment center (HTC) for evaluation and management of heavy menstrual bleeding (HMB) and iron deficiency anemia (IDA) DESIGN: In this single-center retrospective study, we reviewed the clinical characteristics and prevalence of CBDs in postmenarchal females, younger than 22 years of age, referred to an HTC from 2015 to 2021 for evaluation of HMB with or without IDA.

RESULTS

One hundred females, with a mean age of 15 years (range 9-20 years), met initial study criteria, and 95 were included in the final analysis. Forty-five (47%) females were ultimately diagnosed with a CBD. The most prevalent diagnoses were FVII deficiency and type 1 von Willebrand disease (VWD) (42.3%, n = 19 each). Forty-two percent of patients with FVII deficiency had a low-for-age FVII activity level, 21.1% were only positive for the FVII R353Q variant associated with borderline FVII levels, whereas 36.8% had both a low-for-age FVII activity level and a positive R353Q variant. Eighty percent of patients with a CBD were found to have relatives with abnormal bleeding symptoms.

CONCLUSION

Congenital FVII deficiency is prevalent among female adolescents experiencing HMB with or without IDA. In addition to VWD, evaluation for this specific factor deficiency should be considered as part of the initial CBD workup. Presence of abnormal bleeding history in the family could also help to predict presence of a CBD.

Recombinant activated factor VII administration in a patient with congenital lack of factor VII undergoing laparoscopic hysterectomy: A case report

INTRODUCTION AND IMPORTANCE

Case report of patient with congenital lack of factor VII, suffering from recurrent hematomas and massive menstrual bleedings resulting in severe anemia and multiple hospitalization.

CASE PRESENTATION

Patient was diagnosed with endometrial hyperplasia and not responding to hormonal treatment and substitution with recombinant factor VII was not effective to reduce the bleedings. This case describes successful laparoscopic technique of using bipolar coagulation and non-absorbable clips.

CLINICAL DISCUSSION

We describe premedication and post-surgical management - which we had to modify from this found in very scarce literature. Despite previous vaginal deliveries without any complications during the puerperium, 20 days after the surgery patient presented with intraperitoneal bleeding after stopping rFVIIa therapy. It was treated medically without the need for re-laparoscopy.

CONCLUSION

Laparoscopic surgery is possible in patients with lack and deficiency of FVIIa, but they need close post-operative surveillance and prolonged supplementation with recombinant FVIIa.

Peculiar Congenital Factor VII Defect with the Proposita and Her Mother Showing the Same Compound Heterozygosity for Thr384Met and Arg413Gln

OBJECTIVE

To investigate a family with factor VII (FVII) deficiency from Argentina.

PATIENTS AND METHODS

The proposita is a 14-year-old girl who presented with a mild to moderate bleeding tendency. Menorrhagia is controlled with periodical administration of small doses of recombinant FVII concentrate. The mother of the proposita has a similar bleeding tendency.

RESULTS

FVII activity in both patients was 20% of normal; FVII antigen was 35% of normal. Molecular biology investigation revealed that the proposita was compound heterozygote between Thr384Met and Arg413Gln. The mother had the same mutations. This was due to the fact that the father of the proposita and her maternal grandfather both carried, in spite of no relation, the same mutation, namely Arg413Gln.

CONCLUSIONS

The identical defect which presented in the propositaand her mother could be explained by the genetic analysis of the father and maternal grandfather of the proposita who happened to have the same mutation (Arg413Gln).

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.

The effect of the chemical chaperone 4-phenylbutyrate on secretion and activity of the p.Q160R missense variant of coagulation factor FVII

Background

Congenital coagulation factor (F) VII deficiency is a rare bleeding disorder caused by mutations in the F7 gene. The missense factor FVII variant p.Q160R is the disease-causing mutation in all Norwegian FVII deficient patients and results in reduced biological activity and antigen levels of FVII in patient plasma. Previous in vitro studies on this variant demonstrated impaired intracellular trafficking and reduced secretion, possibly due to protein misfolding. The aim of the study was therefore to assess the impact of chemical chaperones on cellular processing and secretion of this variant using a cell model based on overexpression of the recombinant protein.

Results

Through screening of compounds, we identified 4-phenylbutyrate (4-PBA) to increase the secretion of recombinant (r) FVII-160R by ~ 2.5-fold. Additionally, treatment with 4-PBA resulted in a modest increase in specific biological activity. Intracellular localization studies revealed that upon treatment with 4-PBA, rFVII-160R was secreted through Golgi and Golgi reassembly-stacking protein (GRASP)-structures.

Conclusions

The present study demonstrates that the chemical chaperone 4-PBA, restores intracellular trafficking and increases the secretion of a missense FVII variant with functional properties in the extrinsic coagulation pathway.

An overview of inherited factor VII deficiency

Factor VII (FVII) deficiency is the most common of the Rare Inherited Coagulation Disorders. The inheritance is autosomal recessive but there is variable penetrance. Overall there is poor correlation between the FVII level and the bleeding phenotype. Heterozygotes may have significant bleeding and severe homozygotes, or compound heterozygotes can be asymptomatic. Typically, homozygotes have FVII levels <10% and heterozygotes have levels above that. In most cases bleeding is uncommon with FVII levels>10-20%. A personal and family history is essential to determine the bleeding risk and to plan for surgical and obstetrical prophylaxis. Severe bleeding complications including central nervous system bleeding, gastrointestinal system bleeding and bleeding into the joints occurs in 10-15% of FVII deficient patients. Mucocutaneous bleeding is a common symptom but 30% of patients are asymptomatic. Fifty to 69% of women have heavy menstrual bleeding. Due to the limited number of publications regarding this rare disorder there are no consensus guidelines. There is registry data which has led to the best recommendations for treatment of bleeding episodes, initiation of long-term prophylaxis in addition to surgical plus ante and peripartum prophylaxis. Recombinant FVII concentrate is the best replacement therapy and a review of treatment and prophylaxis dosing is discussed.

Acquired Factor VII deficiency - a rare but important consideration

INTRODUCTION

Isolated acquired Factor VII deficiency is a rare coagulation disorder which is independent of vitamin K deficiency. The exact pathophysiological basis of this condition is unclear. We present a series of cases highlighting different clinical scenarios where this condition was encountered.

CASE SERIES

The first case presented with intra-abdominal sepsis. The second was a patient admitted with acute kidney injury and subsequently diagnosed with myeloma. The final case presented with microangiopathic haemolytic anaemia and was suspected of having atypical Haemolytic Uraemic Syndrome. In each case, there was no family or personal history of a bleeding disorder. Follow-up Factor VII levels after recovery from illness was normal in all three cases.

CONCLUSION

Acquired Factor VII deficiency is an uncommon but important finding which should be considered in the general medical setting when an isolated prolonged prothrombin time is detected.

Factor VII Gene Defects: Review of Functional Studies and Their Clinical Implications

Coagulation factors belong to a family of plasma glycosylated proteins that should be activated for appropriate blood coagulation. Congenital deficiencies of these factors cause inheritable hemorrhagic diseases. Factor VII (FVII) deficiency is a rare bleeding disorder with variable clinical symptoms. Various mutations have been identified throughout the F7 gene and can affect all the protein domains. The results of previous experiments have partly revealed the correlation between genotype and phenotype in patients with FVII deficiency. Nevertheless, each particular variant may affect the coagulative function of FVII, mainly via altering its expression level, extra-cellular secretion, tissue factor binding affinity, or proteolytic activity. The pathogenicity of the variants and molecular mechanisms responsible for clinical symptoms in patients with FVII deficiency should be characterized via in silico and in vitro, as well as in vivo functional studies. This review has highlighted the most important functional studies reported on F7 gene variants, including relevant reports regarding Iranian FVII deficiency patients.

Prophylaxis of peripartum haemorrhage using recombinant factor VIIa (rfVIIa) in pregnant women with congenital factor VII deficiency: A case report and literature review

Congenital factor VII deficiency is a rare autosomal recessive disorder associated to different haemorrhagic manifestations. Labour and delivery may cause bleeding risk in patients with this coagulation deficit, thus it is appropriate to clarify whether prophylaxis of peripartum haemorrhage is necessary. To date, there are very few cases in scientific literature which report the management of women with congenital factor VII deficiency during labour, and a consensus for prophylaxis does not exist. In this manuscript we present the management of a 35 years old woman with factor VII deficiency, treated with recombinant factor VIIa before delivery, without haemorrhagic complications either for the woman and for the infant. Therefore, we present a review of similar cases managed with a peripartum prophylaxis with recombinant factor VIIa, and discuss its usefulness and effectiveness, in view of the severity of the deficit and the doses used.

Hemophagocytic lymphohistiocytosis and congenital factor VII deficiency: a case report

Background

Hemophagocytic lymfohistiocytosis (HLH) is a rare, life-threatening hyperinflammation, characterized by immune system over-activation resulting in hemophagocytosis. HLH could appear as a primary disease caused by mutations of immune-regulatory genes, or develop as a result of viral or bacterial infections, or malignancy. Congenital factor VII (FVII) deficiency is a rare autosomal recessive disorder characterized by prolonged prothrombin time (PT) and low FVII, which may increase bleeding risk.

Case presentation

A 50-year-old woman was admitted for a fever persisted for 20 days, presenting with cytopenia, high hyperferritinemia, low activity of NK cells. Bone marrow aspiration showed hemophagocytosis. CT scanning found pulmonary infection. EBV and CMV were not detected. Genetic scanning did not find pathogenic mutation of a HLH NGS panel including 26 genes. This patient was treated as recommended by the HLH 2004 Guidelines. Coagulation tests identified FVII deficiency. Genetic analysis of F7 gene in the patient and her family members identified recurrent compound heterozygous F7 c.64 + 5G > A and c.1224 T > G (p.His408Gln) mutations in this patient and her brother who showed postoperative hemorrhage after surgical resection of renal cell carcinoma. Heterozygotes in this family were asymptomatic.

Conclusions

To our knowledge, this is the first report of HLH in combination with congenital FVII deficiency in Chinese population.

Recurrent Bleedings in Newborn: A Factor VII Deficiency Case Report

Background: Major hemorrhages in newborns can be caused by several conditions, and knowledge of the differential diagnosis is essential in order to ensure prompt recognition and appropriate treatment. Case Report: We describe the case of a male newborn experiencing recurrent hemorrhages from the first days of life. Laboratory findings showed normal platelet count, hepatic function, and C-reactive protein. Coagulation tests detected an isolated prothrombin time (PT) prolongation and severe factor VII (FVII) deficiency. Conclusion: Inherited FVII deficiency is a rare autosomal recessive bleeding disorder. Clinical presentation is heterogeneous, and bleeding severity is not directly related to FVII levels. Acute bleeding episodes can be treated with human plasma-derived FVII (pdFVII) or recombinant activated FVII (rFVIIa). In case of severe deficiency, prophylaxis must be evaluated. Awareness of this condition is crucial in order to establish prompt diagnosis and treatment.

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.

Continuous infusion of human prothrombin complex in a patient with congenital factor VII deficiency undergoing laparoscopic cholecystectomy: A case report from China

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We describe a case of successful replacement treatment with PPSB, without episodes of bleeding and thrombosis.

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This is the first report of the patient with congenital FVII deficiency undergoing laparoscopic cholecystectomy with repeated administration of PPSB.

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PPSB is made in China, it also provides direction for the use of other similar drugs to solve the same problem.

Introduction

Factor VII deficiency is a rare cause of haemorrhagic syndrome. PRESENTATION OF CASE: The authors describe a case of a 48 years old patient with congenital factor VII deficiency suffering abdominal discomfort diagnosed as gallstone, that successfully underwent laparoscopic cholecystectomy with continuous infusion of Human Prothrombin Complex(PPSB) around the procedure.

Conclusion

The usage of PPSB solved the clotting problems enabling the surgical procedure, without risks for the patient.

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.

Elevated prothrombin time on routine preoperative laboratory results in a healthy infant undergoing craniosynostosis repair: Diagnosis and perioperative management of congenital factor VII deficiency

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Factor VII deficiency is a rare autosomal disorder with genotypic and phenotypic variability.

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Preoperative lab evaluation should at a minimum consist of a hematocrit, platelet count, type and screen, and coagulation studies for high-risk surgeries.

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Treatment of acute hemorrhage in factor VII deficient patients primarily consists of factor VII (FVII) replacement therapy.

Introduction

Congenital factor VII deficiency is a rare bleeding disorder with high phenotypic variability. It is critical that children with congenital Factor VII deficiency be identified early when high-risk surgery is planned. Cranial vault surgery is common for children with craniosynostosis, and these surgeries are associated with significant morbidity mostly secondary to the risk of massive blood loss.

Presentation of case

A two-month old infant who presented for elective craniosynostosis repair was noted to have an elevated prothrombin time (PT) with a normal activated partial thromboplastin time (aPTT) on preoperative labs. The infant had no clinical history or reported family history of bleeding disorders, therefore a multidisciplinary decision was made to repeat the labs under general anesthesia and await the results prior to incision. The results confirmed the abnormal PT and the case was canceled. Hematologic workup during admission revealed factor VII deficiency. The patient underwent an uneventful endoscopic strip craniectomy with perioperative administration of recombinant Factor VIIa.

Discussion

Important considerations for perioperative laboratory evaluation and management in children with factor VII deficiency are discussed. Anesthetic and surgical management of the child with factor VII deficiency necessitates meticulous planning to prevent life threatening bleeding during the perioperative period.

Conclusion

A thorough history and physical examination with a high clinical suspicion are vital in preventing hemorrhage during surgeries in children with coagulopathies. Abnormal preoperative lab values should always be confirmed and addressed before proceeding with high-risk surgery. A multidisciplinary discussion is essential to optimize the risk-benefit ratio during the perioperative period.

Management of Labour and Delivery in a Patient With Acquired Factor VII Deficiency With Inhibitor: A Case Report

BACKGROUND

Acquired factor VII (FVII) deficiency with inhibitor increases the risk of hemorrhage during pregnancy. However, there are no published reports guiding its management in the peripartum period.

CASE

A 24-year-old woman with inhibitory antibodies to FVII delivered at 34 weeks of gestation. The patient was administered recombinant factor VIIa (rFVIIa) and tranexamic acid. There were no bleeding-related complications; however, the FVII level was supratherapeutic. The patient returned during a second pregnancy. A reduced dose of rFVIIa was administered. The delivery was complicated by postpartum hemorrhage, which resolved with the addition of uterotonic agents.

CONCLUSION

Recombinant FVIIa and tranexamic acid offer an effective peripartum treatment in women with inhibitory antibody to FVII. Further research should delineate the optimal time of administration.

Heterozygous congenital Factor VII deficiency with the 9729del4 mutation, associated with severe spontaneous intracranial bleeding in an adolescent male

BACKGROUND

In congenital Factor (F) VII deficiency bleeding phenotype and intrinsic FVII activity levels don't always correlate. Patients with FVII activity levels <30% appear to have a higher bleeding propensity, but bleeding can also occur at higher FVII activity levels. Reasons for bleeding at higher FVII activity levels are unknown, and it remains challenging to manage such patients clinically.

CASE

A 19year old male with spontaneous intracranial hemorrhage and FVII activity levels of 44%, requiring emergent surgical intervention and a strategy for FVII replacement. Genotyping showed the rare heterozygous FVII 9729del4 mutation. Bleed evacuation was complicated by epidural abscess requiring craniectomy, bone graft procedures, and prolonged administration of recombinant human (rh) activated FVII (FVIIa). The patient recovered without neurological deficits, and remains on prophylactic low dose treatment with rhFVIIa in relation to risky athletic activities.

CONCLUSION

For clinicians, it is important to recognize that effects of rhFVIIa within these pathways are independent of its contribution to blood clot formation and cannot be assessed by clotting assays. Reduced FVII levels should therefore not be dismissed, as even a mild reduction may result in spontaneous bleeding. Treatment of mild FVII deficiency requires a careful case-by-case approach, based on the clinical scenario.

Large deletions play a minor but essential role in congenital coagulation factor VII and X deficiencies

Congenital factor VII (FVII) and factor X (FX) deficiencies belong to the group of rare bleeding disorders which may occur in separate or combined forms since both the F7 and F10 genes are located in close proximity on the distal long arm of chromosome 13 (13q34). We here present data of 192 consecutive index cases with FVII and/or FX deficiency. 10 novel and 53 recurrent sequence alterations were identified in the F7 gene and 5 novel as well as 11 recurrent in the F10 gene including one homozygous 4.35 kb deletion within F7 (c.64+430_131-6delinsTCGTAA) and three large heterozygous deletions involving both the F7 and F10 genes. One of the latter proved to be cytogenetically visible as a chromosome 13q34 deletion and associated with agenesis of the corpus callosum and psychomotor retardation.

CONCLUSIONS

Large deletions play a minor but essential role in the mutational spectrum of the F7 and F10 genes. Copy number analyses (e. g. MLPA) should be considered if sequencing cannot clarify the underlying reason of an observed coagulopathy. Of note, in cases of combined FVII/FX deficiency, a deletion of the two contiguous genes might be part of a larger chromosomal rearrangement.

Hemipelvectomy after severe pelvic injury in Factor VII deficiency toddler

Traumatic hemipelvectomy is a lethal catastrophic injury. The reported average age of individuals surviving this trauma is 21 years old, suggesting the necessity of good physiological reserves to survive this type of injury. Dealing with this injury in children may call for special requirements throughout all the stages of diagnosis, treatment and rehabilitation. Experience in the resuscitation and subsequent treatment of individuals suffering from this traumatic condition in the paediatric population is even scarce. There are only several reported cases involving children and none of the paediatric cases suffered from comorbidities prior to their traumatic injury. The present report describes the successful management of a 16-month-old child with a medical history of a rare bleeding disorder a severe coagulation Factor VII deficiency who underwent right-sided traumatic hemipelvectomy.

Successful management of maternal factor VII deficiency in a cesarean section

Factor VII (FVII) deficiency is an infrequent hereditary bleeding disorder that can make excessive bleeding in surgical interventions, such as a postpartum hemorrhage in a cesarean section. Although a recombinant form of activated FVII has been applied for bleeding control in FVII-deficient patients, its applications in the field of obstetrics are still limited, especially in Korea. Replacement of blood products is still preferred as first-line therapy, with antifibrinolytic agents used as adjunctive therapy. We report herein the case of a successful cesarean section in an 18-year-old woman with FVII deficiency.

Conformational Changes of Congenital FVII Variants with Defective Binding to Tissue Factor ARG304GLN (FVII Padua), ARG 304TRP (FVII Nagoya) and ARG79GLN (FVII Shinjo or Tondabayashi)

BACKGROUND

The relation between Factor VII (FVII) and tissue thromboplastin is not completely clarified, yet. Three FVII abnormalities, FVII Padua (Arg304Gln), FVII Nagoya (Arg304Trp) and FVII Shinjo or Tondabayshi (Arg79Gln) show different FVII activity according to the tissue Tissue Factor (TF) used in the assay system (rabbit brain, human placenta or human recombinant and ox brain).

OBJECTIVES

To investigate the possible existence of common conformational changes with regard to different tissue factors in these three FVII variants.

MATERIAL AND METHODS

Crystal structure analysis and "visual inspection" of FVII were deeply performed to select a crystallographic template for the in silico mutagenesis procedure of FVII Arg79Gln, Arg304Gln and Arg304Trp.100ns 300K NVT large-scale molecular dynamics simulation on GPU were applied to the models of FVII. The aims of this run was to describe at molecular level the influence of the mutation on the protein structure and function.

RESULTS

The molecular modelling of those three variants has shown common features in spite of the different location of the mutation involved (the first epidermal growth factor for the Arg79Gln and the catalytic region for the Arg304Gln or Arg304Trp). Molecular dynamics studies have shown in fact that the mutant FVII, shows a decreased flexibility or freezing of the protein conformation of FVIIa with regard to TF. This results in the formation of a defective FVIIa-TF complex that justifies the different clotting results observed in these variants according to the TF used.

CONCLUSIONS

The conformational studies may supply useful information on the structure- function relation of clotting factors.

Factor VII Deficiency: A Rare Case Report

Factor VII deficiency is a rare congenital coagulopathy. Prolonged prothrombin time with normal partial thromboplastin time indicates factor VII deficiency. For the definitive diagnosis, the specific factor VII level should be investigated. We report a 20 day old, baby girl, born full-term who was admitted with the diagnosis of sepsis. Hematological tests revealed prolonged prothrombin time and a factor VII level of nine percent. After antibiotic therapy and fresh frozen plasma replacement, her clinical status improved but the prothrombin time continued to be prolonged. On the seventh day of discharge the baby died due to sudden intracranial hemorrhage.