1. Division of Transfusion Medicine, Department of Laboratory Medicine University of Washington Seattle Washington USA
2. Department of Pathology and Laboratory Medicine Dartmouth‐Hitchcock Medical Center Lebanon New Hampshire USA
3. Transfusion Medicine NHS Blood and Transplant Oxford UK
4. Department of Haematology Oxford University Hospitals, NHS Foundation Trust Oxford UK
5. Radcliffe Department of Medicine University of Oxford and NIHR Oxford Biomedical Research Centre (Haematology) Oxford UK