1. Academic Haematology Unit, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom;
2. McMaster Centre for Transfusion Research, Department of Medicine and Department of Pathology and Molecular Medicine, McMaster University and Canadian Blood Services, Hamilton, ON, Canada;
3. Division of Hematology/Oncology, Department of Pediatrics, Weill Cornell Medicine, New York, NY;
4. St. George Hospital, NSW Health Pathology, University of New South Wales, Sydney, NSW, Australia;
5. Department of Haematology, Hammersmith Hospital, London, United Kingdom;
6. Seattle Cancer Care Alliance, University of Washington, Seattle, WA;
7. Departments of Research, Medicine and Oncology, Østfold Hospital Trust, Grålum, Norway;
8. Department of Hematology, Institute of Clinical Medicine, Oslo University, Oslo, Norway;
9. Centre de Référence des Cytopénies Auto-Immunes de l'Adulte, Service de Médecine Interne, CHU Henri Mondor, AP-HP, Université Paris-Est Créteil, Créteil, France;
10. Department of Hematology, Hospital Universitario de Burgos, Burgos, Spain;
11. Department of Haematology, Royal Manchester Children’s Hospital, Manchester, United Kingdom;
12. Department of Haematology, Qilu Hospital, Shandong University, Jinan, China;
13. Platelet Disorder Support Association, Cleveland, OH;
14. Royal London Hospital, Barts Health NHS Trust, London, United Kingdom;
15. Haematology Theme Oxford Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom;
16. Hematology Project Foundation, Affiliated to the Department of Cell Therapy and Hematology, San Bortolo Hospital, Vicenza, Italy;
17. Department of Haematology, University College London Hospital, Cardiometabolic Programme-NIHR UCLH/UCL BRC, London, United Kingdom;
18. Department of Blood Transfusion, Osaka University Hospital, Osaka, Japan;
19. Sir YK Pao Centre for Cancer and Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong;
20. SC Ematologia, Azienda Sanitaria Universitaria Integrata, Trieste, Italy; and
21. Division of Hematology, Massachusetts General Hospital, Harvard Medical School, Boston, MA