Management of rare inherited bleeding disorders: Proposals of the French Reference Centre on Haemophilia and Rare Coagulation Disorders

INTRODUCTION

The rare coagulation disorders may present significant difficulties in diagnosis and management. In addition, considerable inter-individual variation in bleeding phenotype is observed amongst affected individuals, making the bleeding risk difficult to assess in affected individuals. The last international recommendations on rare inherited bleeding disorders (RIBDs) were published by the United Kingdom Haemophilia Centre Doctors' Organisation in 2014. Since then, new drugs have been marketed, news studies on surgery management in patients with RIBD have been published, and new orphan diseases have been described.

AIM

Therefore, the two main objectives of this review, based on the recent recommendations published by the French Reference Centre on Haemophilia and Rare Bleeding Disorders, are: (i) to briefly describe RIBD (clinical presentation and diagnostic work-up) to help physicians in patient screening for the early detection of such disorders; and (ii) to focus on the current management of acute haemorrhages and long term prophylaxis, surgical interventions, and pregnancy/delivery in patients with RIBD.

The Hemarthrosis-Simulating Knee Model: A Useful Tool for Individualized Education in Patients with Hemophilia (GEFACET Study)

Background

Hemophilic arthropathy is a major complication in patients with severe hemophilia. A plastic knee model has been developed for the therapeutic education of patients to promote improved care management and self-treatment skills. The objective of this study was to evaluate the impact of this hemarthrosis-simulating artificial knee (HSAK) on patients’ knowledge of their disease and its treatment.

Methods

In this observational study, the impact of HSAK was assessed during individualized education in patients with severe/moderately severe hemophilia A or B at seven hemophilia treatment centers in France. Participants provided written informed consent and completed questionnaires to assess knowledge of their disease (score range: 0–7) and knowledge of their treatment (score range: 0–4). Questionnaires were completed before, immediately after and 6 months after HSAK use. The scores obtained before and after the use of the HSAK were compared.

Results

The participants comprised 32 children, 29 teenagers, and 31 adults. The mean (SD) disease knowledge score increased significantly in all age groups of patients from 4.5 (2.0) to 5.9 (1.5; p<0.001) immediately after the training and remained unchanged at 6 months. Mean (SD) treatment knowledge scores were unchanged, but Wilcoxon signed rank testing showed a significant increase after the training course that was maintained at 6 months in children and teenagers.

Conclusion

These findings suggest that an individualized training course can enhance the understanding of hemophilia in patients of all ages, especially in children and teenagers, and that the HSAK may assist in improving patients’ management of their disease.

Molecular cytogenetic characterization of five F8 complex rearrangements: utility for haemophilia A genetic counselling

BACKGROUND

Genomic inversions are usually balanced, but unusual patterns have been described in haemophilia A (HA) patients for intron 22 (Inv22) and intron 1 (Inv1) inversions leading to the hypothesis of more complex rearrangements involving deletions or duplications.

AIM

To characterize five abnormal patterns either in Southern blot and long-range PCR for Inv22 or in PCR for Inv1.

MATERIALS AND METHODS

All patients were studied using cytogenetic microarray analysis (CMA).

RESULTS

In all cases, CMA analysis found that each inversion was associated with complex Xq28 rearrangement. In three patients, CMA analysis showed large duplication ranging from 230 to 1302 kb and encompassing a various number of contiguous genes among which RAB39B. RAB39B duplication is a strong candidate gene for X-linked intellectual disability (XLID). Surprisingly, none of the severe HA patients with RAB39B duplication reported in this study or in the literature exhibited XLID. We hypothesise that F8 complex rearrangement down regulated RAB39B expression. In the two remaining patients, CMA analysis found Xq28 large deletion (from 285 to 522 kb). Moyamoya syndrome was strongly suspected in one of them who carried BRCC3 deletion.

CONCLUSION

Because several F8 neighbouring genes are associated with other pathologies such as XLID and cardiovascular disease, all HA patients where complex Xq28 rearrangement was suspected should be referred to a geneticist for possible utility of a pangenomic study. Such investigation should be carefully considered in genetic counselling in female carriers to assess the risk of transmitting severe HA with a "contiguous gene syndrome".

Natural history and clinical characteristics of inhibitors in previously treated haemophilia A patients: a case series

BACKGROUND

Development of inhibitors is the most serious complication in haemophilia A treatment. The assessment of risk for inhibitor formation in new or modified factor concentrates is traditionally performed in previously treated patients (PTPs). However, evidence on risk factors for and natural history of inhibitors has been generated mostly in previously untreated patients (PUPs). The purpose of this study was to examine cases of de novo inhibitors in PTPs reported in the scientific literature and to the EUropean HAemophilia Safety Surveillance (EUHASS) programme, and explore determinants and course of inhibitor development.

METHODS

We used a case series study design and developed a case report form to collect patient level data; including detection, inhibitor course, treatment, factor VIII products used and events that may trigger inhibitor development (surgery, vaccination, immune disorders, malignancy, product switch).

RESULTS

We identified 19 publications that reported 38 inhibitor cases and 45 cases from 31 EUHASS centres. Individual patient data were collected for 55/83 (66%) inhibitor cases out of 12 330 patients. The median (range) peak inhibitor titre was 4.4 (0.5-135.0), the proportion of transient inhibitors was 33% and only two cases of 12 undergoing immune tolerance induction failed this treatment. In the two months before inhibitor development, surgery was reported in nine (22%) cases, and high intensity treatment periods reported in seven (17%) cases.

CONCLUSIONS

By studying the largest cohort of inhibitor development in PTPs assembled to date, we showed that inhibitor development in PTPs, is on average, a milder event than in PUPs.

Treatment of severe von Willebrand disease with a high-purity von Willebrand factor concentrate (Wilfactin): a prospective study of 50 patients

BACKGROUND AND OBJECTIVES

A plasma-derived von Willebrand factor (VWF) concentrate with low factor VIII (FVIII) content was specifically developed to treat von Willebrand disease (VWD). Efficacy and safety were investigated by merging the results of two comparable protocols conducted prospectively in 5 European and 12 French centers.

METHODS AND RESULTS

Fifty patients with clinically severe VWD (72% had VWF ristocetin cofactor activity less than 10 IU dL(-1) and 46% had FVIII < 20 IU dL(-1)) were treated with the concentrate as the only therapy, except for clinical situations requiring a priming dose of FVIII to rapidly correct an intrinsic coagulation defect. A total of 139 spontaneous bleeding episodes were treated; only 53 (38%) needed a concomitant FVIII dose. Outcome was excellent or good in 89% of the episodes. Forty-four patients underwent 108 surgical or invasive procedures. Outcome was excellent or good in 95 scheduled procedures (only VWF was infused) and 13 emergency procedures (a priming FVIII dose was co-administered with the first VWF infusion). There were no thrombotic complications and none of the 18 patients with type 3 VWD developed anti-VWF or anti-FVIII antibodies.

CONCLUSIONS

This concentrate safely and effectively provides hemostasis in patients with clinically severe VWD.

Extractions dentaires chez l’enfant présentant une maladie hémorragique constitutionnelle : protocole thérapeutique et résultats

INTRODUCTION

We report the results of our 10-year experience with a protocol of local hemostasis specifically elaborated for children with congenital bleeding disorders.

MATERIAL AND METHOD

Sixty-four dental extractions procedures were performed in 37 children. Local hemostasis was achieved with the CO2 laser at the site of extraction previously filled with regenerated oxidized cellulose. The site of extraction was then protected with thermomolded splint. The replacement therapy (hemostasis factor concentrates, platelet concentrates) was coordinated by the hematologist and restricted as much as possible.

RESULTS

160 decidual teeth and 23 permanent teeth were extracted. None of the children with minor bleeding deficiency received replacement therapy. Ten post-operative bleedings were recorded but none was considered severe.

DISCUSSION

This protocol characterized by the use of CO2 laser for the hemostasis gave satisfaction in children. The rare and minor post-operative bleedings could be explained by multiple extractions, local infection and/or children's anxiety. This strategy requires a close cooperation between the stomatologist and the hematologist in order to determine the optimal therapeutic management.

Rituximab alone or in association with corticosteroids in the treatment of acquired factor VIII inhibitors: report of two cases

Acquired haemophilia is a factor VIII (FVIII) deficiency due to autoantibodies directed against FVIII that can be responsible for severe haemorrhage. The therapeutic approach, in addition to the treatment of bleeding episodes with clotting factor infusion, relies on corticosteroids (CS), cyclophosphamide (CYC), and/or high-dose intravenous immunoglobulins (IVIg). However, the efficacy of IVIg is limited, and CS and CYC may cause a number of adverse effects. Recently, rituximab has been proposed, alone or in combination with CS and immunosuppressants in a small number of patients with acquired anti-FVIII antibodies with a good efficacy. We report here on two patients, aged 74 and 81, respectively, who developed acquired haemophilia, with high titre FVIII inhibitors and severe haemorrhage, in the absence of a detectable cause. Both of them received rituximab as a first line therapy with a marked and prolonged efficacy.

Impact of Choice of Treatment for Bleeding Episodes on Inhibitor Outcome in Patients With Mild/Moderate Hemophilia A and Inhibitors

Patients with mild/moderate hemophilia A (MHA) may develop inhibitors to factor VIII (FVIII). In this condition, FVIII clotting activity (FVIII:C) baseline levels may remain stable for some patients, but may be reduced to less than 0.01 U/mL for others. Several risk factors for the development of inhibitors in MHA have been proposed. Genetic factors, such as mutations in the FVIII gene, may play a central role; however, other influences, such as intensive treatment with FVIII products, may also be important. Optimal treatment regimens have yet to be determined, not only for the eradication of inhibitors, but also for the management or surgical prophylaxis of hemorrhages associated with this condition. Several treatment options for the control of bleeding in patients with MHA and inhibitors (MHAI) are currently available, and the choice of therapeutic strategy should be given careful consideration; some treatments may produce an anamnestic response, thus delaying the return to FVIII:C baseline levels and adversely affecting the duration of the severe bleeding phenotype. To increase our knowledge of MHAI, a retrospective collection of data is currently being performed among hemophilia centers in France and Belgium. Based on five examples of patients with MHAI collated from preliminary study data, we illustrate the impact on inhibitor outcome of the therapeutic choices used to treat bleeding episodes in these patients.

Continuous infusion of B-domain deleted recombinant factor VIII (ReFacto) in patients with haemophilia A undergoing surgery: clinical experience

This retrospective, open-label, non-comparative study evaluated continuous infusion of recombinant factor VIII (ReFacto), B-domain deleted recombinant FVIII (BDDrFVIII), in patients with haemophilia A undergoing surgery and requiring >5 consecutive days of treatment. Sixteen patients from eight centres underwent a total of 20 procedures. Haemostatic outcome was assessed as 'excellent' or 'good' in 75% of procedures, and target FVIII:C levels were maintained throughout the continuous infusion period. The reported volume of blood loss during surgery was also within the normal range for non-haemophilic patients for the type of surgery performed. Red blood cell transfusions were required to balance excessive blood loss during BDDrFVIII continuous infusion in eight (40%) procedures (seven patients), five with bleeding or requiring volume replacement and three to treat anaemia secondary to blood loss. Non-serious adverse events considered by investigators as possibly or probably related to BDDrFVIII continuous infusion were infrequent (n = 5) considering the duration of treatment (n =239 cumulative days of continuous infusion), and all of these were mild-to-moderate in severity. No thromboembolic complications were reported except for one case of thrombophlebitis occurring at the infusion site. Only two patients (four events) experienced serious adverse bleeding; BDDrFVIII was otherwise well-tolerated. These data show that continuous infusion of BDDrFVIII provides reliable haemostasis and is an effective and well-tolerated regimen for patients with haemophilia A undergoing surgery.