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    Poster Networking

    Hemophilia and Rare Bleeding Disorders

    Poster Networking Session

    PB0680 - Clinical characteristics, therapy and outcome of children with Hemophilia B and inhibitors: a PedNet study

    Monday, June 26, 2023
    18:30 – 19:30 ET
    Room: Exhibition

      Presenting Author(s)

    • Assaf Barg, MD

      Pediatric Hematologist
      The National Hemophilia Center, and Amalia Biron Research Institute of Thrombosis and Hemostasis, Sheba Medical Center, Ramat Gan, Israel
      Tel Aviv, HaMerkaz, Israel

      • Co-Author(s)

    • MD

      Marloes De Kovel, MSc

      Epidemiologist and Research Coordinator at PedNet
      PedNet Haemophilia Research Foundation, Baarn, the Netherlands.
      Baarn, Drenthe, Netherlands

    • HP

      Helen Pergantou

      PAEDIATRICIAN, DIRECTOR OF HAEMOPHILIA CENTRE/HEAMOSTASIS AND THROMBOSIS UNIT
      Haemophilia Centre/Haemostasis and Thrombosis Unit, “Aghia Sophia” Children’s Hospital, Athens, Greece
      Athens, Argolis, Greece

    • Roseline d'Oiron, MD

      Director
      Centre for Haemophilia and Rare Congenital Bleeding Disorders, Bicêtre Hospital AP-HP, University of Paris-Saclay and UMR_S1176 INSERM, Le Kremlin-Bicêtre, France
      Le Kremlin-Bicetre, France

    • BN

      Beatrice Nolan

      Pediatric hematologist
      Department of Haematology, Children's Health Ireland at Crumlin, Dublin, Ireland.
      Dublin, Dublin, Ireland

    • Carmen Escuriola-Ettingshausen, MD

      Physician
      Haemophilia Centre Rhine-Main, Mörfelden-Walldorf, Germany
      Mörfelden-Walldorf, Hessen, Germany

    • Kathelijn Fischer, MD, PhD (she/her/hers)

      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

      Medical Doctor
      Department of Paediatrics and Malmö Centre for Thrombosis and Haemostasis, Skåne University Hospital, Malmö, Sweden.
      Malmo, Blekinge Lan, Sweden

    • HG

      Heidi Glosli

      Medical Doctor
      Division of Paediatric and Adolescent Medicine Centre for Rare Disorders Oslo University Hospital Oslo Norway.
      Oslo, Oslo, Norway

    • Maria Teresa Alvarez-Román, MD, PhD

      Associate Professor
      Department of Hematology, University Hospital La Paz, Autonoma University of Madrid, Madrid, Spain
      Madrid, Madrid, Spain

    • JM

      Jayashree Motwani

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

    • 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

    • Christoph Male, MD, MSc

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

    Background: Inhibitors in hemophilia B (HB) pose major challenges, since they are commonly associated with anaphylactic reactions as well as nephrotic syndrome and thus hamper successful immune tolerance induction (ITI).

    Aims: To study the clinical characteristics, complications, treatment strategies, and outcome of children with HB and inhibitors (HBI).

    Methods: The PedNet Registry is a prospective cohort study enrolling previously untreated hemophilia patients born after January 2000 and followed at 34 participating centers. Baseline and follow up data of all children with HBI was retrieved. Data included all relevant clinical factors, treatment, and clinical outcome

    Results: The study cohort comprised 15 children with HBI (14 severe, 1 moderate HB). Clinical and genetic risk factors for inhibitor development have previously been reported for the majority of this cohort. Patient demographics, inhibitor characteristics, therapeutic strategies, and outcome are listed in Table 1. Median age at inhibitor development was 23 months (IQR:13-46). Inhibitors were detected following a median of 12 exposure days (IQR:10-50) to F9 concentrate. Patients were followed for a median of 7.8 years (range: 2.4-18 years) after inhibitor detection. Most patients (73%) had high titer inhibitors with a median peak inhibitor level 22 BU (IQR: 3-32). Eight patients (53%) had anaphylactic reactions to FIX associated with the inhibitor. ITI was attempted in 53% of the cohort, One patient developed nephrotic syndrome during ITI. Although most patients followed currently have no measurable inhibitor, most of them still require treatment with a bypassing agent (Table 1).

    Conclusion(s): The findings of our real-life data demonstrate that inhibitors in HB, although rare, cause significant morbidity and are challenging to eradicate. Thus, there is an unmet need for improved therapy of HBI patients.