Recessively inherited coagulation disorders

A rare combination: congenital factor VII deficiency with Chiari malformation

Congenital factor (VII) deficiency is a rare bleeding disorder. We present a patient with congenital FVII deficiency and congenital hydrocephalus who underwent a ventriculoperitoneal shunt operation and needed no prophylaxis after the procedure.

Hepatic fibrinogen storage disease: identification of two novel mutations (p.Asp316Asn, fibrinogen Pisa and p.Gly366Ser, fibrinogen Beograd) impacting on the fibrinogen γ-module

BACKGROUND

Quantitative fibrinogen deficiencies (hypofibrinogenemia and afibrinogenemia) are rare congenital disorders characterized by low/unmeasurable plasma fibrinogen antigen levels. Their genetic basis is invariably represented by mutations within the fibrinogen genes (FGA, FGB and FGG coding for the Aα, Bβ and γ chains). Currently, only four mutations (p.Gly284Arg, p.Arg375Trp, delGVYYQ 346-350, p.Thr314Pro), all affecting the fibrinogen γ chain, have been reported to cause fibrinogen storage disease (FSD), a disorder characterized by protein aggregation, endoplasmic reticulum retention and hypofibrinogenemia.

OBJECTIVES

To investigate the genetic basis of FSD in two hypofibrinogenemic patients.

METHODS

The mutational screening of the fibrinogen genes was performed by direct DNA sequencing. The impact of identified mutations on fibrinogen structure was investigated by in-silico molecular modeling. Liver histology was evaluated by light microscopy, electron microscopy and immunocytochemistry.

RESULTS

Here, we describe two hypofibrinogenemic children with persistent abnormal liver function parameters. Direct sequencing of the coding portion of fibrinogen genes disclosed two novel FGG missense variants (p.Asp316Asn, fibrinogen Pisa; p.Gly366Ser, fibrinogen Beograd), both present in the heterozygous state and affecting residues located in the fibrinogen C-terminal γ-module. Liver sections derived from biopsies of the two patients were examined by immunocytochemical analyses, revealing hepatocyte cytoplasmic inclusions immunoreactive to anti-fibrinogen antibodies.

CONCLUSIONS

Our work strongly confirms the clustering of mutations causing FSD in the fibrinogen γ chain between residues 284 and 375. Based on an in-depth structural analysis of all FSD-causing mutations and on their resemblance to mutations leading to serpinopathies, we also comment on a possible mechanism explaining fibrinogen polymerization within hepatocytes.

Using a Systems Pharmacology Model of the Blood Coagulation Network to Predict the Effects of Various Therapies on Biomarkers

A number of therapeutics have been developed or are under development aiming to modulate the coagulation network to treat various diseases. We used a systems model to better understand the effect of modulating various components on blood coagulation. A computational model of the coagulation network was built to match in-house in vitro thrombin generation and activated Partial Thromboplastin Time (aPTT) data with various concentrations of recombinant factor VIIa (FVIIa) or factor Xa added to normal human plasma or factor VIII-deficient plasma. Sensitivity analysis applied to the model revealed that lag time, peak thrombin concentration, area under the curve (AUC) of the thrombin generation profile, and aPTT show different sensitivity to changes in coagulation factors' concentrations and type of plasma used (normal or factor VIII-deficient). We also used the model to explore how variability in concentrations of the proteins in coagulation network can impact the response to FVIIa treatment.

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.

Treatment for preventing bleeding in people with haemophilia or other congenital bleeding disorders undergoing surgery

BACKGROUND

In people with haemophilia or other congenital bleeding disorders undergoing surgical interventions, haemostatic treatment is needed in order to correct the underlying coagulation abnormalities and minimise the bleeding risk. This treatment varies according to the specific haemostatic defect, its severity and the type of surgical procedure. The aim of treatment is to ensure adequate haemostatic coverage for as long as the bleeding risk persists and until wound healing is complete.

OBJECTIVES

To assess the effectiveness and safety of different haemostatic regimens (type, dose and duration, modality of administration and target haemostatic levels) administered in people with haemophilia or other congenital bleeding disorders for preventing bleeding complications during and after surgical procedures.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews.Date of the last search: 20 November 2014.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing any hemostatic treatment regimen to no treatment or to another active regimen in children and adults with haemophilia or other congenital bleeding disorders undergoing any surgical intervention.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials (eligibility and risks of bias) and extracted data. Meta-analyses were performed on available and relevant data.

MAIN RESULTS

Of the 16 identified trials, four (112 participants) were eligible for inclusion.Two trials evaluated 59 people with haemophilia A and B undergoing 63 dental extractions. Trials compared the use of a different type (tranexamic acid or epsilon-aminocaproic acid) and regimen of antifibrinolytic agents as haemostatic support to the initial replacement treatment. Neither trial specifically addressed mortality (one of this review's primary outcomes); however, in the frame of safety assessments, no fatal adverse events were reported. The second primary outcome of blood loss was assessed after surgery and these trials showed the reduction of blood loss and requirement of post-operative replacement treatment in people receiving antifibrinolytic agents compared with placebo. The remaining primary outcome of need for re-intervention was not reported by either trial.Two trials reported on 53 people with haemophilia A and B with inhibitors treated with different regimens of recombinant activated factor VII (rFVIIa) for haemostatic coverage of 33 major and 20 minor surgical interventions. Neither of the included trials specifically addressed any of the review's primary outcomes (mortality, blood loss and need for re-intervention). In one trial a high-dose rFVIIa regimen (90 μg/kg) was compared with a low-dose regimen (35 μg/kg); the higher dose showed increased haemostatic efficacy, in particular in major surgery, with shorter duration of treatment, similar total dose of rFVIIa administered and similar safety levels. In the second trial, bolus infusion and continuous infusion of rFVIIa were compared, showing similar haemostatic efficacy, duration of treatment and safety.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised controlled trials to assess the most effective and safe haemostatic treatment to prevent bleeding in people with haemophilia or other congenital bleeding disorders undergoing surgical procedures. Ideally large, adequately powered, and well-designed randomised controlled trials would be needed, in particular to address the cost-effectiveness of such demanding treatments in the light of the increasing present economic constraints, and to explore the new challenge of ageing patients with haemophilia or other congenital bleeding disorders. However, performing such trials is always a complex task in this setting and presently does not appear to be a clinical and research priority. Indeed, major and minor surgeries are effectively and safely performed in these individuals in clinical practice, with the numerous national and international recommendations and guidelines providing regimens for treatment in this setting mainly based on data from observational, uncontrolled studies.

Total knee arthroplasty in a patient with hypofibrinogenemia

Patients with afibrinogenemia or hypofibrinogenemia present a unique challenge to the arthroplasty surgeon as fibrinogen is a key contributor to hemostasis. Patients with these disorders are known to have a higher risk for postsurgical bleeding complications. We present the case of a patient with hypofibrinogenemia who underwent an elective total knee arthroplasty. Our colleagues in hematology-oncology guided us initially to achieve and maintain appropriate fibrinogen levels in the early perioperative period. However, the patient developed an acute joint effusion and subsequent infection 4 weeks after her initial operation. Her fibrinogen levels were noted to have fallen below the target range by that time, and it was also revealed that the patient failed to follow-up with hematology-oncology to monitor her levels. Based on our review of the available literature, we recommend that patient's fibrinogen levels be closely monitored and maintained ideally >100 mg/dL not only in the initial perioperative window but perhaps for the first 4-6 weeks postoperatively as well.

Safety of fibrinogen concentrate: analysis of more than 27 years of pharmacovigilance data

Fibrinogen concentrate use as a haemostatic agent has been increasingly explored. This study evaluates spontaneous reports of potential adverse drug reactions (ADRs) that occurred during postmarketing pharmacovigilance of Haemocomplettan P/RiaSTAP, and reviews published safety data. This descriptive study analysed postmarketing safety reports recorded in the CSL Behring pharmacovigilance database from January 1986 to December 2013. A literature review of clinical studies published during the same period was performed. Commercial data indicated that 2,611,294 g of fibrinogen concentrate were distributed over the pharmacovigilance period, corresponding to 652,824 standard doses of 4 g each, across a range of clinical settings and indications. A total of 383 ADRs in 106 cases were reported (approximately 1 per 24,600 g or 6,200 standard doses). Events of special interest included possible hypersensitivity reactions in 20 cases (1 per 130,600 g or 32,600 doses), possible thromboembolic events in 28 cases (1 per 93,300 g or 23,300 doses), and suspected virus transmission in 21 cases (1 per 124,300 g or 31,000 doses). One virus transmission case could not be analysed due to insufficient data; for all other cases, a causal relationship was assessed as unlikely due to negative polymerase chain reaction tests and/or alternative explanations. The published literature revealed a similar safety profile. In conclusion, underreporting of ADRs is a known limitation of pharmacovigilance. However, the present assessment indicates that fibrinogen concentrate is administered across a range of indications, with few ADRs and a low thromboembolic event rate. Overall, fibrinogen concentrate showed a promising safety profile.

Clinical and molecular characterisation of 21 patients affected by quantitative fibrinogen deficiency

Fibrinogen is a plasma glycoprotein mainly synthesised by hepatocytes and circulating as a 340-kDa hexamer consisting of two sets of three different polypeptide chains (Aα, Bβ, and γ, encoded by the FGA, FGB, and FGG gene, respectively). Congenital afibrinogenaemia and hypofibrinogenaemia are rare bleeding disorders characterised by abnormally low levels of functional and immunoreactive fibrinogen in plasma, associated with haemorrhagic manifestations of variable severity. While afibrinogenaemia is caused by mutations in the homozygous or compound heterozygous state in one of the three fibrinogen genes, hypofibrinogenaemia is generally due to heterozygous mutations, and is usually characterised by a milder phenotype. The mutational spectrum of these quantitative fibrinogen disorders includes large deletions, point mutations causing premature termination codons, and missense mutations often affecting fibrinogen assembly and/or secretion. Here we report the clinical and molecular characterisation of 13 unrelated afibrinogenaemic and eight hypofibrinogenaemic patients, leading to the identification of 17 different mutations (10 hitherto unknown). All the newly-identified missense and splicing mutations werein vitro expressed to verify their pathogenic role. Our data increase the number of mutations causing quantitative fibrinogen deficiencies by about 7 %. The high number of private mutations identified in the analysed probands indicates that the full mutational screening of the three fibrinogen genes is still required for molecular diagnosis.

A novel congenital dysprothrombinemia leading to defective prothrombin maturation

INTRODUCTION

Prothrombin deficiency is a very rare disorder caused by mutations in the F2 gene that generate hypoprothrombinemia or dysprothrombinemia and is characterized by bleeding manifestations that can vary from clinically irrelevant to life-threatening.

AIM

Here we characterize a patient with a novel missense mutation in F2, c.1090T/A (p.Val322Glu), that causes severe dysprothrombinemia.

METHODS

Coagulation assays, prothrombin Western Blotting, FII activation by Ecarin, fibrinogen degradation products quantification and thrombin generation assay were carried out to assess prothrombin expression and function. PCR followed by direct sequencing was carried out to characterize the mutation. In silico analysis for missense variant and molecular modeling were applied to predict the mechanism that leads to dysprothrombinemia.

RESULTS AND CONCLUSIONS

The homozygous patient had a markedly prolonged prothrombin time, strongly reduced FII activity (0.82%) but normal antigen levels. In the thrombin generation assay the lag time and the peak height were unmeasurable, suggesting that the Val322Glu mutation results in the inability of the mutant prothrombin to be fully activated to thrombin. In fact, prothrombin activation by ecarin was defective, with a massive accumulation of the meizothrombin intermediate. Molecular modeling and dynamic simulation studies showed that the Val322Glu mutation interferes with protein flexibility at Arg271 and Arg320. This impairs the switch of the protein from zymogen to proteinase, thus preventing the formation of thrombin. Accumulated meizothrombin, however, maintains some fibrinogen-degrading activity, as shown by the formation of FDPs, and this probably explains the patient's mild bleeding phenotype.

Spontaneous splenic rupture in a patient with congenital afibrinogenemia

Afibrinogenemia is a rare bleeding disorder which is observed with an incidence of 1:1 000 000. It is an autosomal recessive disease and occurs as a result of mutation in one of the three genes which code the three polypeptide chains of fibrinogen. Basic clinical findings include spontaneous bleeding, bleeding after minor trauma or due to surgery. Splenic rupture in afibrinogenemia has been reported only in 6 cases so far. In this article, we present a 15-year old congenital afibrinogenemia patient with spontaneous splenic rupture.

Use of Factor XIII (FXIII) concentrate in patients with congenital FXIII deficiency undergoing surgical procedures

BACKGROUND

Patients with congenital Factor XIII (FXIII) deficiency have impaired fibrin stabilization and are at high risk for surgical bleeding. Data regarding the use of FXIII concentrates before and during surgery are lacking. The objective of this study was to report the use of plasma-derived FXIII concentrate (Corifact in the United States; Fibrogammin P in other countries) in patients with congenital FXIII deficiency undergoing surgical procedures.

STUDY DESIGN AND METHODS

FXIII concentrate at preoperative doses ranging from 25 to 40 U/kg was administered to six patients with congenital FXIII deficiency undergoing major or minor surgeries.

RESULTS

FXIII concentrate was administered immediately before surgery for five surgical cases; three of these patients achieved excellent hemostasis during and after surgery, while two had intraoperative bleeding. In one surgical case, a regular prophylactic dose of FXIII concentrate was administered to the patient 1 week before minor surgery. FXIII concentrate provided rapid replacement of FXIII activity. In all but one of the patients given a dose of FXIII designed to increase FXIII levels more than 50%, there was satisfactory intraoperative and postoperative hemostasis. One patient undergoing aortic valve replacement on cardiopulmonary bypass (CPB) was the exception. Intraoperative bleeding in this patient was associated with lower-than-expected blood levels of FXIII.

CONCLUSION

Preoperative plasma-derived FXIII concentrate allowed for sufficient hemostasis in most patients with FXIII deficiencies. Additional doses were necessary to achieve hemostasis in one patient who underwent a CPB procedure.

Genotype and phenotype report on patients with combined deficiency of factor V and factor VIII in Iran

Combined factor V (FV) and factor VIII (FVIII) deficiency is a rare autosomal recessive bleeding disorder characterized by mild-to-moderate bleeding. Epistaxis, postsurgical bleeding and menorrhagia are the most common symptoms. The aim of this study is to report the phenotype-genotype characterization carried out in patients affected with combined FV and FVIII deficiency from Iran. A cross-sectional study was conducted in Shiraz Hemophilia Center, southern Iran. Twelve cases, seven men and five women coming from eight families were included in our study after taking consent form. Coagulation activity for all patients was measured. All exons and intron-exon junctions of lectin mannose binding protein 1 (LMAN1) gene and multiple coagulation factor deficiency 2 genes were amplified by PCR, and subsequently sequenced by the Sanger method. Patients[Combining Acute Accent] age ranged from 6 to 59 years mean ± SD: 23.8 ± 15.4 years and median: 22 years. No patient presented with severe bleeding symptom. Only one patient had severe FV and FVIII deficiency (both factor levels <1%). Four different type of mutations (duplication, insertion, splice site and nonsense), occurring in different locuses, were identified on LMAN1 gene in 12 Iranian patients. There was a significant correlation between FV and FVIII levels, which is indicative of association with loss of function of LMAN1 gene, and reduced plasma levels of both factors. Our study showed that all of our characterized patients with combined FV and FVIII deficiency present different homozygous mutations on LMAN1 gene introducing a premature stop codon. Larger studies are needed to calculate the correlation between factor levels, genetic and bleeding symptoms.

Successful Pregnancy in a Patient with Combined Deficiency of Factor V and Factor VIII

Inherited combined factor V and factor VIII deficiency (F5F8D) is autosomal recessive transmission disorder. Epistaxis, postsurgical bleeding, and menorrhagia are the most common symptoms. The risk of miscarriage and placental abruption is consequent. We report a case of successful pregnancy in a patient with F5F8D. 20-year-old woman, born of consanguineous parents, third gestate, first parity, two miscarriages, admitted for child birth of a spontaneous pregnancy estimated at 38 weeks and was diagnosed with F5F8D. At admission, patient was hemodynamically stable, with good obstetric conditions. The biologic results showed low levels of PT (52%), factor V (7%), and factor VIII (5%), and the activated partial thromboplastin time was prolonged (68,6%). Parturient was admitted in intensive care unit, maternal and fetal monitoring was performed. Fresh frozen plasma (FFP) and factor VIII concentrates were perfused at the induction of labor. Analgesia used fentanyl titration. The delivery gave birth to a newborn male, with Apgar 10/10 and 3000 g. The puerperium was simple without any important bleeding. Laboratory tests for the newborn were acceptable. Little literature is available on this subject and there are no guidelines available concerning pregnancy; we chose to prescribe a combination of factor VIII concentrate and FFP in pre-, per- and postpartum. The same protocol was successfully used in a patient before dental extraction and prostatectomy. Vaginal delivery is possible, as our case. Management by multidisciplinary team is recommended.

Bleeding diathesis and hemophilias

Patients with hemophilia and other congenital bleeding disorders are at risk for development of central nervous system (CNS) hemorrhage and can present with acute or chronic neurologic symptoms. These disorders are generally caused by qualitative or quantitative deficiency of components of hemostasis such as coagulation proteins, von Willebrand factor, or platelets. Rapid diagnosis and specific medical management such as coagulation factor replacement therapy are mandatory to minimize the morbidity and mortality of CNS bleeding. Therefore, the objective of this chapter is to introduce neurologists to the physiology of hemostasis and to provide an overview of the clinical presentation, and management of inherited bleeding disorders that can potentially present with CNS bleeding. Since hemophilia is the most common bleeding disorder encountered in clinical practice, more emphasis is placed on management of hemophilia. Additionally, neurologic manifestations related to the bleeding diathesis in patients with hemophilia are elaborated.

Inherited abnormalities of coagulation: hemophilia, von Willebrand disease, and beyond

Bleeding disorders are broadly classified into primary and secondary hemostatic defects. Primary hemostatic disorders (disorders of platelets and von Willebrand factor) mainly result in mucocutaneous bleeding symptoms such as epistaxis, menorrhagia, petechiae, easy bruising, and bleeding after dental and surgical interventions. Secondary hemostatic disorders (congenital or acquired deficiencies of coagulation factors) typically manifest with delayed, deep bleeding into muscles and joints. This article provides a generalized overview of the pathophysiology, clinical manifestations, laboratory abnormalities, and molecular basis of inherited abnormalities of coagulation with a focus on hemophilia, von Willebrand disease, and rare inherited coagulation disorders.

The clinical findings and prophylactic treatment in children with factor X deficiency

Factor X (FX) is the component of both extrinsic and intrinsic coagulation cascade and is the first enzyme of the common pathway which results in thrombus. Congenital FX deficiency (FXD) is an extremely rare coagulation defect. In this study, we aimed to investigate the clinical and laboratory data of the patients diagnosed with FXD. The files of the 15 patients (7 female, 8 male) diagnosed and followed up for FXD within the last 4 years were evaluated retrospectively. The mean age of the patients was 29 months (min-max:1-144 months). The most presenting complaints were easy bruisability (n = 8; 53%) and epistaxis (n = 8; 53%). FX levels were <1% in six patients, 1-5% in four patients, and >5% in five patients. Heparin added-Protrombin Complex was used for prophlaxy (n = 11; 73%). Any treatment-related complication was not observed. Heparin-added PCC can be used safely for effective prophlaxy. We suggest that family history is important when considering prophlaxy and in patients with life-threatening bleeding or with FXD sibling the prophlaxy should be introduced in the early course.

Rare bleeding disorders in children: identification and primary care management

Bleeding symptoms are common in healthy children but occasionally may indicate an underlying congenital or acquired bleeding diathesis. The rare bleeding disorders (RBDs) comprise inherited deficiencies of coagulation factors I (congenital fibrinogen deficiencies), II, V, VII, X, XI, and XIII and combined factor deficiencies, most notably of factors V and VIII and of vitamin K-dependent factors. These disorders often manifest during childhood and may present with recurrent or even serious or life-threatening bleeding episodes, particularly during the neonatal period. Accordingly, primary care and other nonhematologist pediatric providers should be familiar with the clinical presentation and initial evaluation of these rare disorders. Bleeding manifestations generally vary within the same RBD and may be indistinguishable from 1 RBD to another or from other more common bleeding disorders. Serious bleeding events such as intracranial hemorrhage may be heralded by less serious bleeding symptoms. The results of initial coagulation studies, especially prothrombin time and activated partial thromboplastin time, are often helpful in narrowing down the potential factor deficiency, with factor XIII deficiency being an exception. Consultation with a hematologist is advised to facilitate accurate diagnosis and to ensure proper management and follow-up. The approach to bleeding episodes and invasive procedures is individualized and depends on the severity, frequency, and, in the case of procedures, likelihood of bleeding. Prophylaxis may be appropriate in children with recurrent serious bleeding and specifically after life-threatening bleeding episodes. When available, specific purified plasma-derived or recombinant factor concentrates, rather than fresh frozen plasma or cryoprecipitate, are the treatment of choice.

Surgical interventions in childhood rare factor deficiencies: a single-center experience from Turkey

Congenital rare factor deficiencies may present in infancy by life-threatening bleedings or may not show any symptoms until adulthood. It is reported more commonly in countries having consanguineous marriages. Data regarding surgical interventions of rare congenital factor deficiencies are based on case reports and records of guidelines. There are no well documented and separately prepared directories related to pre-surgical and prophylactic approaches of surgical interventions of these deficiencies. Our retrospective study consisted of 171 rare factor deficiencies that were followed up in our clinic, and of whom 61 had 88 surgical interventions between 1990 and 2012. Of these patients, 45 were having factor VII deficiency, and factor V, X, XI, XIII and fibrinogen deficiencies were present in five, four, three, two and two patients, respectively. In 23 patients, factor coagulant activities were under 5% (37.7%), in 15 it was between 5 and 30% (24.6%), and in 23 between 30 and 50% (37.7%). Twenty-eight were symptomatic and 33 were asymptomatic. Information of 51 (83.6%) male and 10 (16.4%) female patients with an age range of 5-25 years (13 ± 5.27), whose age at presentation ranged between 3 weeks and 18 years (7 ± 4.66), were retrieved from patient records and from the records contained in the data-processing environment introduced in 2005. The rate of familial consanguinity was 49.2%. Of the surgical interventions, 24 (27.3%) were major, 24 (27.3%) were minor and 40 (45.4%) were circumcision. We used fresh frozen plasma in 32, recombinant factor (rF)VIIa in 20, prothrombin complex concentrate in five and fibrinogen in three patients during surgical interventions. In 18 patients, antifibrinolytic agents were also used. In 27 patients, surgical interventions were applied without any replacement therapy. No additional doses were required after surgical prophylaxis doses. Thrombotic events were not observed. Antibody occurrence was not detected in these patients. In our study, we evaluated preparation for surgical procedures, factor replacement therapy before surgical intervention and postoperative follow-up in patients with rare coagulation factor deficiency.

Genetic sequence analysis of inherited bleeding diseases

The genes encoding the coagulation factor proteins were among the first human genes to be characterized over 25 years ago. Since then, significant progress has been made in the translational application of this information for the 2 commonest severe inherited bleeding disorders, hemophilia A and B. For these X-linked disorders, genetic characterization of the disease-causing mutations is now incorporated into the standard of care and genetic information is used for risk stratification of treatment complications. With electronic databases detailing >2100 unique mutations for hemophilia A and >1100 mutations for hemophilia B, these diseases are among the most extensively characterized inherited diseases in humans. Experience with the genetics of the rare bleeding disorders is, as expected, less well advanced. However, here again, electronic mutation databases have been developed and provide excellent guidance for the application of genetic analysis as a confirmatory approach to diagnosis. Most recently, progress has also been made in identifying the mutant loci in a variety of inherited platelet disorders, and these findings are beginning to be applied to the genetic diagnosis of these conditions. Investigation of patients with bleeding phenotypes without a diagnosis, using genome-wide strategies, may identify novel genes not previously recognized as playing a role in hemostasis.

Pre-interventional haemostatic assessment: Guidelines from the French Society of Anaesthesia and Intensive Care

Recently the French Society of Anaesthesia and Intensive Care (Société Française d'Anesthésie et de Réanimation [SFAR]) issued recommendations for the prescription of routine preoperative testing before a surgical or non-surgical procedure, requiring any type of anaesthesia. Thirty clinical specialists performed a systematic analysis of the literature, and recommendations were then developed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. One part of these guidelines is dedicated to haemostatic assessment. The goal of pre-anaesthetic screening for congenital or acquired haemostatic disorders is to prevent perioperative haemorrhagic complications through appropriate medical and surgical management. Preoperative assessment of bleeding risk requires a detailed patient interview to determine any personal or family history of haemorrhagic diathesis, and a physical examination is necessary in order to detect signs of coagulopathy. Laboratory investigation of haemostasis should be prescribed, not systematically, but depending on clinical evaluation and patient history. Standard tests (prothrombin time, activated partial thromboplastin time, platelet count) have a low positive predictive value for bleeding risk in the general population. Patients with no history of haemorrhagic diathesis and no conditions liable to interfere with haemostasis should not undergo pre-interventional haemostasis testing. Conversely, the existence of a positive history or a disease that could interfere with haemostasis should be an indication for clinically appropriate testing.

Fibrinogen Level as a Surrogate for the Outcome of Thrombolytic Therapy Using Tissue Plasminogen Activator for Acute Lower Extremity Intravascular Thrombosis

Purpose:

Monitoring of fibrinogen level is used to predict bleeding during lower extremity tissue plasminogen activator (tPA) infusions for peripheral arterial or venous thrombolysis. This practice is not fully addressed in the literature.

Materials and Methods:

We retrospectively reviewed fibrinogen levels and studied bleeding rate from charts of patients who underwent lower extremity tPA infusions at a single hospital from January 2010 to May 2012.

Results:

The rate of thrombolytic success did not correlate with fibrinogen level ( P = .53). The rate of major bleeding was significantly higher for patients with a fibrinogen level at or below 150 mg/dL ( P = .01). Patients whose tPA infusion was terminated within 46 hours had significantly lower rates of major bleeding ( P = .01) and thrombolytic failure ( P < .01). Periprocedural systolic blood pressure above 160 mm Hg was a risk factor for major bleeding ( P = .02). There was no association between concomitant aspirin use ( P = .90, .51) or hourly tPA dose ( P = .71, .62) and thrombolytic success or major bleeding, respectively.

Conclusion:

Fibrinogen level ≤150 mg/dL is associated with increased risk of major bleeding during tPA infusions. We suggest serial fibrinogen measurement as a viable method to monitor bleeding risk during lower extremity tPA infusions.

Percutaneous coronary intervention in a case of afibrinogenemia

Congenital afibrinogenemia is a rare autosomic recessive blood disorder. A 30-year-old lady, known to have congenital afibrinogenemia, presented with acute anterior myocardial infarction. We managed her with dual antiplatelet therapy and atorvastatin, but her chest pain did not subside and she was transferred to the catheterization laboratory. A proximal left anterior descending artery occlusion was crossed with a floppy wire. Angioplasty was performed successfully with a bare metal stent, and her symptoms resolved completely.

Future of coagulation factor replacement therapy

Over a million patients worldwide currently suffer from hemophilia and other congenital clotting factor deficiencies. Patients affected with hemophilia A and B are treated by intravenous replacement therapy of factor VIII and factor IX, respectively. Current hemophilia treatments have favorably supported their efficacy, tolerability, and safety profiles. The onset of alloantibodies inactivating the infused coagulation factor is the main problem in hemophilia patients rendering replacement therapies ineffective; another disadvantage is the short half-life of the infused clotting factors with the need for multiple and frequent infusions to manage a bleeding episode. Now, the challenge in the management of hemophilia treatment is the prolongation of the half-life and reduction in the immunogenicity of recombinant clotting factors. The bioengineering strategies, previously applied successfully to other therapeutic proteins, encourage the current efforts to produce novel coagulation factors with more prolonged bioavailability, with increased potency and resistance to inactivation and potentially reduced immunogenicity.

Prophylactic administration of prothrombin complex concentrates for congenital prothrombin deficiency with a novel frameshift mutation, prothrombin saitama

Prothrombin (Factor II, FII) deficiency is an extremely rare autosomal recessive condition with an estimated incidence of 1:2 million. As severe and life-threatening bleeding is rare in FII deficiency, on demand therapy with administration of prothrombin complex concentrates (PCCs) or fresh frozen plasma is generally performed, and prophylactic therapy for FII deficiency has been reported in only three cases. Thus, its optimal dosage and schedule has remained uncertain. Here we report a case of severe prothrombin deficiency with a novel frameshift mutation of the F2 gene, who was started on prophylactic administration.

A longitudinal prospective study of bleeding diathesis in Egyptian pediatric patients: single-center experience

Keeping an updated registry of bleeding disorders is crucial for planning care and documenting prevalence. We aimed to assess the prevalence of various bleeding disorders including rare inherited coagulation and platelet disorders concerning their clinico-epidemiological, diagnostic data and bleeding manifestations severity. Patients suffering from manifestations of bleeding or coagulation disorders presented to Hematology Clinic during 16 years were included and prospectively followed up. Demographics, clinical characteristics, complete blood count, bleeding, prothrombin and activated partial thromboplastin times, platelet aggregation tests and bone marrow aspiration were recorded. Overall 687 patients with bleeding disorders from total 2949 patients were identified. Inherited coagulation defects were found in 27.2%; hemophilia A (70.6%), hemophilia B (13.9%), factor I deficiency (2.3%), factor V deficiency (1.6%), factor X deficiency (4.2%), factor VII deficiency (2.6%), factor XIII deficiency (1.1%), combined factor deficiency (2.1%) and unclassified coagulation disorders in 1.6% of studied patients. Overall 72.7% had diagnosed with platelet disorders; immune thrombocytopenia was the commonest (74.8%), and inherited conditions represent (25.2%) in the following order: Glanzman's thrombasthenia (11.2%), von Willebrand disease (6.6%), Bernard-Soulier syndrome (1%) and Chediak Higashi in 0.4% and unclassified in 6%. Median age of diagnosis of coagulation and platelet disorders were 33 and 72 months. Presenting symptoms of coagulation disorders were: 25.1% post circumcision bleeding, 22.5% ecchymosis, 20.9% hemoarthrosis and 15% epistaxis. Symptoms of rare coagulation disorders were postcircumcision bleeding (20%), bleeding umbilical stump (20%), epistaxis (12%), hemoarthrosis (8%) and hematomas (4%). Presenting symptoms in rare inherited platelet disorders were purpura, ecchymosis, epistaxis and bleeding gums, respectively. Analysis of the clinico-epidemiological data of patients with bleeding disorders is a useful tool for monitoring and improving their quality of care.

Comparison of Thrombin Generation Assay With Conventional Coagulation Tests in Evaluation of Bleeding Risk in Patients With Rare Bleeding Disorders

Based on the premise that the capacity of plasma to generate thrombin in vitro is a comprehensive and precise functional test of the clotting system, we designed a cross-sectional, single-center study involving 83 patients with rare bleeding disorders (RBDs) to compare the usefulness of the thrombin generation (TG) assay versus conventional tests including prothrombin time (PT) and activated partial thromboplastin time (aPTT) in predicting bleeding risk in patients with RBD in southern Iran. The TG parameters consisted of endogenous thrombin potential, lag time, peak, time to peak (ttPeak), and start tail. The area under the receiver–operating characteristic (ROC) curve showed statistically significant associations between bleeding risk and lag time, ttPeak, and start tail. We determined cutoff values for these 3 TG parameters and obtained a negative predictive value of 86% to 90% in patients with RBD who had a bleeding score (BS) ≤13. The ROC curves for the association of PT and aPTT with BS did not indicate any significant association. Correlation analysis supported the results of ROC curve analysis, only lag time, ttPeak, and start tail showed significant positive correlations with BS ( P < .05). Disease severity based on plasma factor activity was significantly associated with prolonged lag time and ttPeak and with prolonged PT ( P <.05). We suggest that TG assay is a potentially more useful tool for predicting the bleeding risk in patients with RBD. However, the small sample size in different RBD subgroups precluded subgroup analysis. Prospective multicenter studies with larger numbers of patients are therefore advisable.

The rare inherited coagulation disorders

The rare inherited coagulation disorders (RICD) are uncommon and thus not well-defined in terms of severity or management. Inheritance is autosomal; in some of these disorders in the heterozygote state affected individuals may be mildly symptomatic. Severe deficiencies are more common in association with consanguinity. Factor X and factor XIII deficiency have the most severe manifestations, while factor XI deficiency is the least severe. Factor VII and factor XI deficiencies show a poor relationship between the factor level and bleeding risk. Unlike hemophilia, women are equally affected by these RICD and can have problems related to menstruation and childbirth.

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.

Replacement therapy for bleeding episodes in factor VII deficiency. A prospective evaluation

Patients with inherited factor VII (FVII) deficiency display different clinical phenotypes requiring ad hoc management. This study evaluated treatments for spontaneous and traumatic bleeding using data from the Seven Treatment Evaluation Registry (STER). One-hundred one bleeds were analysed in 75 patients (41 females; FVII coagulant activity <1-20%). Bleeds were grouped as haemarthroses (n=30), muscle/subcutaneous haematomas (n=16), epistaxis (n=12), gum bleeding (n=13), menorrhagia (n=16), central nervous system (CNS; n=9), gastrointestinal (GI; n=2) and other (n=3). Of 93 evaluable episodes, 76 were treated with recombinant, activated FVII (rFVIIa), eight with fresh frozen plasma (FFP), seven with plasma-derived FVII (pdFVII) and two with prothrombin-complex concentrates. One-day replacement therapy resulted in very favourable outcomes in haemarthroses, and was successful in muscle/subcutaneous haematomas, epistaxis and gum bleeding. For menorrhagia, single- or multiple-dose schedules led to favourable outcomes. No thrombosis occurred; two inhibitors were detected in two repeatedly treated patients (one post-rFVIIa, one post-pdFVII). In FVII deficiency, most bleeds were successfully treated with single 'intermediate' doses (median 60 µg/kg) of rFVIIa. For the most severe bleeds (CNS, GI) short- or long-term prophylaxis may be optimal.

Congenital factor II deficiency: moroccan cases

BACKGROUND

Clotting factor II, or prothrombin, is a vitamin K-dependent proenzyme that functions in the blood coagulation cascade. Inherited factor II deficiency is an extremely rare autosomal recessive disorder affecting both genders: clinical bleeding can vary widely in homozygous individuals, and heterozygotes often remain clinically asymptomatic. This study highlights the rarity of inherited factor II deficiency and the importance of coagulation testing in the diagnosis of this condition.

METHODS

We report four cases of factor II deficiency at our institution.

RESULTS

At diagnosis, two patients were 3 days old, whereas the other two patients were 13 and 40 years of age. Three patients were female, and one was male. Symptoms of factor II deficiency were reported at referral in three patients; the deficiency was an incidental finding in the remaining case. The parents of all four patients were consanguineous (first degree). Factor II enzymatic activity was 1% in 3 cases and 5% in the incidental case. The treatment consisted of transfusion with fresh frozen plasma in all cases.

CONCLUSIONS

The congenital deficiency of factor II is a rare inherited disorder. The diagnosis is mainly based on coagulation tests. However, the prognosis of this disease and access to medication are associated with the risk of occurrence of severe bleeding.

[Menorrhagia due to congenital factor V deficiency in an adolescent]

The frequency of menometrorrhagia in adolescence is estimated at 2-5 %. The functional origin is the most common. Hemostasis abnormalities account for 20 % of cases, and they should be sought whenever there is a personal history of known or suggestive of hemostasis disorders (epistaxis, gingival bleeding, postoperative bleeding, bruising, etc.) or there is a family history of hemostasis disorders. Organic origins are rare, but these must be sought when the characteristics of bleeding point in this direction. The workup aims to investigate the cause and assess the impact of the hemorrhage. It may include an NFS, blood group and rhesus±β-HCG, hemostasis evaluation, determination of hemostasis factors, and a pelvic ultrasound. Whatever the cause of menometrorrhagia, the therapeutic options are the same and are oriented by the severity of bleeding. The treatment is mainly medical and hormonal. The surgical option should be a choice of last resort. We report a case of a 13-year-old girl admitted in hemorrhagic shock due to abundant metrorrhagia. Her laboratory tests showed an isolated deficiency of factor V with a 2 % rate. Congenital factor V deficiency is a rare autosomal recessive coagulation disorder. It can be diagnosed at any age when a bleeding disorder of varying severity is observed. The diagnosis is based on the hemostasis evaluation with quantitative determination of factor V. Because no FV-specific concentrate is available, fresh frozen plasma remains the mainstay of treatment. Antifibrinolytics can also be beneficial, and platelet transfusions have been successfully used, associated with hormone therapy. These patients may best be managed in cooperation with both a gynecologist and a hematologist.

Use of pharmacokinetic modelling to individualize FFP dosing in factor V deficiency

Therapy with fresh frozen plasma (FFP) confers serious risks, such as contraction of blood-borne viruses, allergic reaction, volume overload and development of alloantibodies. The aim of this study was to apply principles of pharmacokinetic (PK) modelling to individual factor content of FFP to optimize individualized dosing, while minimizing potential risks of therapy. We used PK modelling to successfully target individual factor replacement in an 8-month-old patient receiving FFP for treatment of a severe congenital factor V (FV) deficiency. The model fit for the FV activity vs. time data was excellent (r = 0.98) and the model accurately predicted FV activity during the intraoperative and postoperative period. Accurate PK modelling of individual factor activity in FFP has the potential to provide better targeted therapy, enabling clinicians to more precisely dose patients requiring coagulation products, while avoiding wasteful and expensive product overtreatment, minimizing potentially life-threatening complications due to undertreatment and limiting harmful product-associated risks.