OR01 - Clinical characteristics of Glanzmann thrombasthenia – First results from the Glanzmann Thrombasthenia Natural History Study
OR01
Clinical characteristics of Glanzmann thrombasthenia – First results from the Glanzmann Thrombasthenia Natural History Study
K. Rutten1,2, G. Castaman3, A. Artoni4, M. Fiore5, M. Mathias6, W. Miesbach7, R. d'Oiron8,9, A. Owen-Wyard10, S. Sivapalaratnam11, R. Schutgens1,* on behalf of EAHAD Glanzmann Thrombasthenia Working Group
1Center for Benign Haematology, Thrombosis and Haemostasis, Van Creveldkliniek, University Medical Center Utrecht, Utrecht, 2Center for Benign Haematology, Thrombosis and Haemostasis, Van Creveldkliniek, University Medical Center Utrecht, Utrecht, Netherlands, 3Center for Bleeding Disorders and Coagulation, Department of Heart Lungs, and Vessels, Careggi University Hospital, Florence, 4Hemophilia and Thrombosis Center, Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Milan, Italy, 5aematology Laboratory, Reference Center for Inherited Platelet Disorders, University Hospital of Bordeaux, Pessac, France, 6Great Ormond Street Hospital for Children, London NHS Foundation Trust, London, United Kingdom, 7The Department of Hemostaseology and Hemophilia Center, University Hospital Frankfurt, Frankfurt, Germany, 8Centre de Référence de l’Hémophilie et des Maladies Hémorragiques Rares, Hôpital Bicêtre APHP, 9INSERM Hémostase Inflammation Thrombose HITH U1176, Université Paris-Saclay, Le Kremlin-Bicêtre, France, 10ERIN patient advisory board, European Haemophilia Consortium, Brussels, Belgium, 11Department of Clinical Haematology, The Royal London Hospital, Barts Health NHS Trust, London, United Kingdom
Introduction: Glanzmann Thrombasthenia (GT) is a severe inherited platelet disorder leading to an increased bleeding tendency. Bleeding phenotype is commonly assessed with the International Society on Thrombosis and Haemostasis (ISTH) Bleeding Assessment Tool (BAT).
Methods: The Glanzmann Thrombasthenia Natural History Study is an international multicenter observational cohort study initiated by the GT working group of the European Association for Haemophilia and Allied Disorders. This study was made possible in part by an unrestricted research grant of Hemab Aps.
Data on clinical characteristics and patient reported outcomes on bleeding phenotype were collected. Besides the (self)-ISTH-BAT for lifetime bleeding, the self-administered Immune Thrombocytopaenia (ITP)-BAT assessed bleeding in the past month. Descriptive data are presented as means/medians and frequencies. Paired self-ITP-BAT differences (baseline vs. 6 months) were tested with Wilcoxon signed-rank and correlation with ISTH-BAT was assessed via Spearman’s test.
Results: Currently, 22 GT patients from 4 centers in the Netherlands and Italy have been included; 50% female, mean age 52 years (range 4-81). Median age at diagnosis was 2 years (IQR 0.5-14.0) and diagnosis was made based on genetic testing, biochemical diagnosis, or a combination of both in 9%, 41%, and 50% respectively. Mean ISTH-BAT score at inclusion was 15.7 (range 3-30). Based on the ISTH-BAT and self-ITP-BAT at inclusion, cutaneous bleeds (86%/81%), epistaxis (77%/76%), and bleeds from minor wound (73%/71%) were most commonly reported during lifetime and in the past month respectively. In the 13 patients who completed the self-ITP-BAT both at baseline (median 10, range 3-27) and 6 months (median 6, range 0-31), no significant difference between the scores was found (p=0.107). There was a significant positive correlation between the self-ITP-BAT and the ISTH-BAT scores at baseline (r = 0.56, p=0.008). 41% of patients required medical treatment due to bleeding in the past month, and 82% of patients required platelet transfusion during lifetime.
Discussion/Conclusion: The first results of the Glanzmann Thrombasthenia Natural History Study show that GT is a severe platelet disorder characterised by mucocutaneous bleeds, often requiring treatment. There seems to be a correlation between bleeding severity experienced over lifetime and that reported in the past month.
Disclosure of Interest: K. Rutten: None declared, G. Castaman: None declared, A. Artoni Consultant for: Sanofi, M. Fiore Grant/Research support from: NovoNordisk, M. Mathias Grant/Research support from: Octapharma, Sobi, Roche and Sanofi, Consultant for: Sobi, W. Miesbach Consultant for: Bayer, BioMarin, Biotest, Chugai, CSL Behring, Novo Nordisk, Pfizer, and Sanofi, R. d'Oiron Grant/Research support from: Takeda, BioMarin, CSL Behring, LFB, Novo Nordisk, Octapharma, Roche/Chugai, Sobi/Sanofi, uniQure and Spark, A. Owen-Wyard: None declared, S. Sivapalaratnam Consultant for: Hemab, R. Schutgens Grant/Research support from: Bayer, CSL Behring, Hemab, Novartis, Novo Nordisk, Octapharma, Roche, Sobi, and Takeda. Roger Schutgens also received concizumab from Novo Nordisk and HMB001 from Hemab for in vitro research purposes.