[Show abstract][Hide abstract] ABSTRACT: Women with inherited bleeding disorders
(IBD) require the input of a multidisciplinary team to
improve outcomes of pregnancy. The role of the
haemophilia nurse within the multidisciplinary team is
to provide educational and emotional support to the
women and to facilitate and co-ordinate patient-centred
care. Prenatal diagnosis in cases of haemophilia is an
integral part of the management of early pregnancy
with a recent drive towards non-invasive prenatal
diagnostic techniques. There is a current lack of data on
the risk of miscarriage and bleeding complications
during pregnancy. A clear association has only been
established in women with fibrinogen and factor XIII
deficiency. In the affected neonate with severe bleeding
disorders such as haemophilia, the risk of head bleeding
is significant, and appropriate management of labour
and delivery has an important impact on reducing the
risk. Women with IBD are at risk of both primary and
secondary postpartum haemorrhage. Appropriate risk
assessment and advance planning for haemostatic cover
can reduce the bleeding risk
[Show abstract][Hide abstract] ABSTRACT: This article describes prenatal diagnosis (PND) of haemophilia B (HB) within the framework of Italian haemophilia centres and genetics laboratories. The study details the experience from six haemophilia genetic centres (three in the North, one in the Centre and two in the South of Italy) and summarizes the different techniques used to perform PND of HB during the last 15 years. To date, the Italian HB database includes 373 characterized unrelated patients and their genetic information has permitted the identification of 274 carriers of childbearing age. This database represents the main instrument for timely and precise PND. Sixty-six prenatal diagnoses were performed on 52 HB carriers whose average age at the time was 34 (ranging from 24 to 44 years). In 44 cases, genetic counselling for carrier status determination was performed before pregnancy, while eight were not studied prior to pregnancy. Foetal samples were obtained by chorionic villus sampling in 52 cases, by amniocentesis in 12 while two were diagnosed by analysis of free foetal DNA obtained from maternal peripheral blood. In 35 (53%) pregnancies the foetus was female. For 31 men (47%), haemophilia status was determined by analysis of previously determined informative markers or familial mutations (12 affected and 19 unaffected). There may be more than one laboratory involved in the PND diagnostic pathway (providing DNA extraction, karyotype analysis, gender determination, maternal contamination detection, molecular diagnosis and sequencing). Good communication between all the parties, coordinated by the haemophilia centre, is essential for a successful and rapid process.
[Show abstract][Hide abstract] ABSTRACT: 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.
Journal of Thrombosis and Haemostasis 06/2013; 11(s1). · 6.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Inhibitor development is influenced by several factors and the type of factor VIII (FVIII) products may play a role.
In order to explore such a role, we designed a cohort study whose novelty resides in the classification of products not only according to the source of FVIII (plasmatic, pd, or recombinant, r) but also to their degree of purity (expressed as specific activity).
Treatment data up to inhibitor development or 150 exposure days were collected in 377 patients with hemophilia A.
Inhibitors developed in 111 patients (29%; 96 high-responders, 25%). The cumulative incidence was progressively higher from patients treated with low/intermediate-purity pdFVIII compared with those treated with high-purity pd and rFVIII. The adjusted hazard ratio of inhibitor development was 4.9 with rFVIII and 2.0 with high-purity pdFVIII (95% CI, 2.9-8.3 and 1.1-4.0), taking as reference low/intermediate-purity pdFVIII. There was no difference in the frequency of inhibitor testing between treatment groups. Sensitivity analyses (in patients who never switched product type, previously untreated patients, those treated on-demand and those with high-risk F8 mutations) confirmed an increased inhibitor risk with rFVIII and high-purity pdFVIII.
This study shows that the degree of purity of FVIII products influences inhibitor development independently from other risk factors, and emphasizes that differences exist within pdFVIII products.
Journal of Thrombosis and Haemostasis 03/2012; 10(5):781-90. · 6.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Prenatal diagnosis (PND) aims to provide accurate, rapid results as early in pregnancy as possible. Conventional PND involves sampling cells of foetal origin by chorionic villus sampling at 11-14th weeks of pregnancy or amniocentesis after 15th week. These are invasive procedures and have a small but significant rate of 0.5% to 1% for loss of pregnancy. An alternative to existing methods for conventional PND for couples at risk of transmitting a genetic disease to their child is preimplantation genetic diagnosis (PGD). PGD is a newly emerging form of a very early prenatal diagnosis. The technique combines assisted reproductive technology with molecular genetics and cytogenetics to allow the identification of abnormality in embryos prior to implantation. The diagnosis of genetic disease in human preimplantation embryos was pioneered in the late 1980s for testing of aneuploidy, single gene and X-linked disease, such as cystic fibrosis, haemophilia and chromosomal abnormalities. The PGD-related legal and ethical issues have been debated at many levels both nationally and internationally. The attitude towards PGD varies substantially not only in different parts of the world but also within the Europe, owing to scientific, cultural and religious differences. PGD has become widely practised throughout the world for various indications and can substantially decrease the eventual risks of passing a genetic undesired condition of the offspring. Nevertheless, its extension to some new and non-medical indications has raised ethical concerns, in particular its potential eugenic dimension.
[Show abstract][Hide abstract] ABSTRACT: Patients affected by bleeding disorders present a wide spectrum of clinical symptoms that vary from a mild or moderate bleeding tendency to significant episodes. Women with inherited bleeding disorders are particularly disadvantaged since, in addition to suffering from general bleeding symptoms, they are also at risk of bleeding complications from regular haemostatic challenges during menstruation, pregnancy and childbirth. Moreover, such disorders pose important problems for affected women due to their reduced quality of life caused by limitations in activities and work, and alteration of their reproductive life. These latter problems include excessive menstrual bleeding or menorrhagia, miscarriage, bleeding complications during pregnancy and after delivery and their related complications such as acute or chronic anaemia. The management of these women is difficult because of considerable inter-individual variation. Moreover, reliable information on clinical management is scarce, only a few available long term prospective studies of large cohorts provide evidence-based guideline about diagnosis and treatment.
Journal of Thrombosis and Haemostasis 07/2011; 9 Suppl 1:236-45. · 6.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Free foetal DNA in maternal blood during early pregnancy is an ideal source of foetal genetic material for non-invasive prenatal diagnosis. The aim of this study was to evaluate the use of free foetal DNA analysis at early gestational age as pretest for the detection of specific Y-chromosome sequences in maternal plasma of women who are carriers of X-linked disorders, such as haemophilia. Real-time quantitative PCR analysis of maternal plasma was performed for the detection of the SRY or DYS14 sequence. A group of 208 pregnant women, at different gestational periods from 4 to 12 weeks, were tested to identify the optimal period to obtain an adequate amount of foetal DNA for prenatal diagnosis. Foetal gender was determined in 181 pregnant women sampled throughout pregnancy. Pregnancy outcome and foetal gender were confirmed using karyotyping, ultrasonography or after birth. The sensitivity, which was low between 4th and 7th week (mean 73%), increased significantly after 7+1th weeks of gestation (mean 94%). The latter sensitivity after 7+1th week of gestation is associated to a high specificity (100%), with an overall accuracy of 96% for foetal gender determination. This analysis demonstrates that foetal gender determination in maternal plasma is reliable after the 9th week of gestation and it can be used, in association with ultrasonography, for screening to determine the need for chorionic villus sampling for prenatal diagnosis of X-linked disorders, such as haemophilia.
[Show abstract][Hide abstract] ABSTRACT: Patients with severe hemophilia may show very varied bleeding tendencies, and the reasons for this heterogeneous clinical expression are unclear. The factor VIII/FIX genotype is the main determinant of the residual factor activity; however, different bleeding phenotypes have also been reported in patients sharing the same mutation. Such global coagulation tests as thrombin generation assays are tools with which to investigate different coagulation profiles among severe hemophiliacs. OBJECTIVES, PATIENTS AND METHODS: This case-control study was aimed at comprehensively evaluating the role of genotype and endogenous thrombin potential (ETP) as predictors of the clinical phenotype in severe hemophiliacs with an extremely mild bleeding tendency (cases, n = 22), in comparison with those showing a typical bleeding tendency (controls, n = 50).
Cases were more frequently affected by hemophilia B than by hemophilia A, and showed a lower incidence of severe FVIII/FIX gene defects (referred to as null mutations), higher FVIII and FIX antigen levels and higher ETP values in platelet-rich plasma than controls (P < 0.05). By multivariate logistic regression, only non-null mutations were confirmed as an independent predictor of a mild clinical phenotype.
These results indicate that non-null mutations represent the main determinant of the bleeding tendency, and that ETP measurement in platelet-rich plasma is able to identify severe hemophiliacs with a mild clinical phenotype.
Journal of Thrombosis and Haemostasis 04/2010; 8(4):737-43. · 6.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To provide a National database, 1,410 unrelated hemophilia A (HA) patients were investigated using screening methods denaturing high-performance liquid chromatography (DHPLC), conformational-sensitive gel electrophoresis (CSGE)] and/or direct sequencing. F8 gene mutations were identified in 877 (81%), 146 (82%), and 133 (89%) families with severe, moderate, or mild HA, respectively. Among the 382 different mutations detected, 217 (57%) have not previously been reported in the F8 Haemophilia A Mutation, Structure, Test and Resource Site (HAMSTeRS) database. Mutations leading to a null allele accounted for 82, 15%, and less than 1% of severe, moderate, or mild HA, respectively. A missense mutation was identified in 16%, 68%, and 81% of severe, moderate, or mild HA, respectively. They included 105 missense mutations (48%), 41 small deletions (19%), 25 splice site mutations (12%), 24 nonsense mutations (11%), 18 insertions (8%), three large deletions (1%), and one deletion plus insertion. Unreported mutations were distributed throughout the F8 gene, as they affected all F8 exons but exon 20. We report a wide spectrum of mutations collected in a large National database. The type of mutation was a strong predictor of the clinical phenotype. This database is expected to considerably improve the genetic counseling and medical care of HA families in Italy.
Journal of Human Genetics 02/2008; 53(3):275-84. · 2.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Inherited deficiencies of plasma proteins involved in blood coagulation generally lead to lifelong bleeding disorders, whose severity is inversely proportional to the degree of factor deficiency. Haemophilia A and B, inherited as X-linked recessive traits, are the most common hereditary hemorrhagic disorders caused by a deficiency or dysfunction of blood coagulation factor VIII (FVIII) and factor IX (FIX). Together with von Willebrand's disease, a defect of primary haemostasis, these X-linked disorders include 95% to 97% of all the inherited deficiencies of coagulation factors. The remaining defects, generally transmitted as autosomal recessive traits, are rare with prevalence of the presumably homozygous forms in the general population of 1:500,000 for FVII deficiency and 1 in 2 million for prothrombin (FII) and factor XIII (FXIII) deficiency. Molecular characterization, carrier detection and prenatal diagnosis remain the key steps for the prevention of the birth of children affected by coagulation disorders in developing countries, where patients with these deficiencies rarely live beyond childhood and where management is still largely inadequate. These characterizations are possible by direct or indirect genetic analysis of genes involved in these diseases, and the choice of the strategy depends on the effective available budget and facilities to achieve a large benefit. In countries with more advanced molecular facilities and higher budget resources, the most appropriate choice in general is a direct strategy for mutation detection. However, in countries with limited facilities and low budget resources, carrier detection and prenatal diagnosis are usually performed by linkage analysis with genetic markers. This article reviews the genetic diagnosis of haemophilia, genetics and inhibitor development, genetics of von Willebrand's disease and of rare bleeding disorders.
[Show abstract][Hide abstract] ABSTRACT: Polymorphic variants in the gene encoding factor VII (F7) affect the plasma levels of this coagulation protein and modify the clinical phenotype of FVII deficiency in some patients. In this study we report the in vitro functional analysis of a novel polymorphic variant located in the 3' untranslated region of F7: g.11293_11294insAA. To determine whether this variant regulates FVII expression, we initially compared an expression vector containing FVII cDNA with g.11293_11294insAA with the FVII wild-type (WT) construct. The kinetics of mRNA production showed that the insertion decreases the steady-state FVII mRNA levels. To assess whether the insertion influences the phenotype of FVII-deficient patients, we evaluated its effect on the expression of FVII in a patient with severe FVII deficiency (undetectable FVII activity and antigen) carrying two additional homozygous missense variations (p.Arg277Cys and p.Arg353Gln). The two substitutions alone reduced the expression of FVII activity and antigen in vitro, but with the insertion polymorphism in our expression vector the patient's phenotype of undetectable plasma FVII was recapitulated. The insertion polymorphism in the 3' untranslated region of F7 is another modifier of FVII expression that might explain the poor genotype-phenotype correlation in some FVII-deficient patients.
Human Mutation 12/2005; 26(5):455-61. · 5.21 Impact Factor