Abstract Number: PB1022
Meeting: ISTH 2020 Congress
Theme: Hemophilia and Rare Bleeding Disorders » Hemophilia - Clinical
Background: Patients with non-severe hemophilia have a milder phenotype compared to patients with severe hemophilia. Nevertheless bleeding episodes elicited by trauma or surgery may have a strong impact on the lives of patients with non-severe hemophilia. Detailed knowledge on the frequency and severity of bleeding in non-severe hemophilia is scant.
Aims: To provide insight in the clinical phenotype of patients with non-severe hemophilia A and B.
Methods: The DYNAMO study is an observational cohort study including hemophilia A and B patients with a baseline clotting factor VIII/IX level of 2-35 IU/dL, aged 12-55 years. Global data on lifetime bleeding history and detailed information on all bleeding episodes from 2009 to present is collected from medical files. The study was approved by medical ethics committees and written consent was obtained (ClinicalTrials.gov Identifier: NCT03623295).
Results: In this preliminary analysis, 101 patients were included (72 HA, 29 HB). The median age was 34 years (IQR 26-48) and the median factor level was 11 IU/dL (IQR 5-17). Eighty patients (79%) experienced at least one bleed that required treatment with factor concentrate (table 1). In the last 10 years, thirty-four patients experienced a total of 176 treated joint bleeds, of which 25 (14%) occurred spontaneously. The majority of all joint bleeds (134/176) and of spontaneous joint bleeds (19/25) were seen in 16 patients with moderate hemophilia. The proportion of joint bleeds out of the total number of treated bleeds was similar between hemophilia A and B (31% and 28% respectively, fig. 1).
Conclusions: Our results suggest that non-severe hemophilia patients may have serious bleeding episodes. On the other hand, 21% of patients have never been exposed to factor concentrate for the treatment of a bleed. These preliminary results highlight the need for careful monitoring of this patient population.
Hemophilia A (n=72) | Hemophilia B (n=29) | Total (n=101) | |
Median factor level in IU/dL | 12 (IQR 5-17) | 11 (IQR 4-16) | 11 (IQR 5-17) |
Lifetime bleeding history | |||
Treated bleed | 57 (79%) | 23 (79%) | 80 (79%) |
Treated joint bleed | 34 (47%) | 11 (38%) | 45 (45%) |
Intracranial hemorrhage | 0 | 2 (7%) | 2 (2%) |
Bleeding history over last 10 years | |||
Number of bleeds | 420 | 128 | 548 |
Number of joint bleeds | 137 | 39 | 176 |
Number of muscle bleeds | 143 | 46 | 189 |
[Table 1. Baseline characteristics, lifetime bleeding history and bleeding history treated with factor concentrate over the period 2009-present.]
[Figure 1. The proportion of treated bleeding events for the total hemophilia population (n=101) over the period 2009-present. ]
To cite this abstract in AMA style:
Zwagemaker A-, Kloosterman FR, Beckers EAM, van der Bom JG, Boyce S, Brons PP, Collins PW, Coppens M, Gouw SC, Harrison C, Leebeek FWG, van der Meer FJM, Meijer K, Nieuwenhuizen L, Fijnvandraat K, DYNAMO Study Group . The Clinical Phenotype of Patients with Non-severe Hemophilia A and B [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/the-clinical-phenotype-of-patients-with-non-severe-hemophilia-a-and-b/. Accessed March 21, 2024.« Back to ISTH 2020 Congress
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