OC 27.1 - The type and frequency of bleeds in 870 children with severe hemophilia A and B on primary prophylaxis: Data from the PedNet study group

Sunday, July 10, 2022

2:45 PM – 3:00 PM

Location: ExCel Center, ICC Capital Suite Room 2-4

Presentation Format: In-Person

Presenting Author(s)

H. Marijke van den Berg, MD, PhD

Director
PedNet
Baarn, Utrecht, Netherlands

Co-Author(s)

MA

Maria teresa Alvarez Roman

Hematologist
Unidad de Coagulopatías, Hopital Universitario La Paz
Madird, Castilla-La Mancha, Spain
Manuel Carcao, MD, FRCPC

Director, Haemophilia Clinic and Haemostasis Program
Hospital for Sick Children, Toronto, Canada
Toronto, Ontario, Canada
HC

Hervé Chambost

Professor and Head of the Comprehensive Care Centre for Congenital Bleeding Disorders
AP-HM, Department of Pediatric Hematology Oncology, Children Hospital La Timone & Aix Marseille University, INSERM, INRA, C2VN, Marseille, France
Marseille, Provence-Alpes-Cote d'Azur, France
KF

Kathelijn Fischer, MD, PhD

Pediatric Hematologist
Center for Benign Haematology, Thrombosis and Haemostasis, Van Creveldkliniek, University Medical Center Utrecht, Utrecht University, The Netherlands
Utrecht, Utrecht, Netherlands
NG

Nadine Gretenkort Andersson

Physician
Lund University
Malmö, Skane Lan, Sweden
Gili Kenet, MD

Director
The National Hemophilia Center, and Amalia Biron Research Institute of Thrombosis and Hemostasis, Sheba Medical Center, Tel Hashomer, Tel Aviv University, Tel Aviv, Israel
Yehud-Monosson, HaMerkaz, Israel
Königs Christoph, Dr. Dr.

Physician
Goethe University Frankfurt, University Hospital, Department of Pediatrics and Adolescent Medicine, Clinical and Molecular Haemostasis, Frankfurt am Main, Germany
Frankfurt, Hessen, Germany
RL

Rolf Ljung

Professor
Lund University, Department of Clinical Sciences
Malmo, Skane Lan, Sweden
Christoph Male, MD, MSc

Head of the Pediatric Hemostasis & Thrombosis Unit
Department of Paediatrics, Medical University of Vienna, Vienna, Austria.
Vienna, Wien, Austria
JM

Jayashree Motwani

Hematologist
Department of Paediatric Haematology, Birmingham Children's Hospital, United Kingdom
Birmingham, England, United Kingdom

Background: Few data exist on long-term follow-up of type and frequency of bleedings in children 0-18 years with severe hemophilia on primary prophylaxis with FVIII/FIX.

Aims: Comparison of reported bleeds in real-world data between different age groups in children with severe hemophilia A (SHA) or B (SHB) on primary prophylaxis.

Methods: The PedNet registry is a multicenter prospective observational cohort study (Clin.gov.trial NCT02979119). For this study we included all children with SHA or SHB without history of inhibitors born between 2000-2020. Data of all bleeds were collected from the start of prophylaxis until January 2021. Bleeds were defined according to the ISTH definition. Bleeding severity was defined as minor when characterized by mild pain, minimal swelling, minimal motion restriction and resolving within 24 hours of treatment, and as major when symptoms persisted >24 hours. Annual bleeding rate (ABR) was based on reported bleeds, using a negative binominal model. Patients were divided into three age groups: 0-5 years, 6-11 years, and 12-18 years.

Results: We included 737 children with SHA and 133 with SHB. The total follow-up years on prophylaxis for SHA was 5838, median 7.5, (IQR 4.0-11.6) and for SHB 1042 years, median 7.7 (IQR 3.7-11.1). Total ABR was 2.8 for SHA and 2.0 for SHB, major joint bleeds were a median (IQR) of 0.36 (0.30-0.43) for SHA and 0.28 (0.21-0.37) for SHB over all three age groups. Minor joint bleeds were a median (IQR) 0.56 (0.51-0.61) for SHA and 0.42(0.34-0.52) for SHB. Minor other bleeds were reported as 1.9 (1.7-2.1) for SHA 1.4(1.1-1.7) for SHB and between 0-5 years (Figure 1).

Conclusion(s): Primary prophylaxis was equally protective in all groups. Reported bleeds in SHB were lower in all groups. In younger patients, the higher reporting of minor bleeds might reflect inadequate prophylaxis or high parental anxiety.