Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada; McMaster Centre for Transfusion Research, Department of Medicine, McMaster University, Hamilton, ON, Canada; Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada; Canadian Blood Services, Ancaster, ON, Canada. Electronic address: arnold@mcmaster.ca. Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada; McMaster Centre for Transfusion Research, Department of Medicine, McMaster University, Hamilton, ON, Canada. Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, ON, Canada. Department of Medicine, Division of Hematology, University of Western Ontario, London, ON, Canada. Department of Medicine, McGill University, Montreal, QC, Canada. McMaster Centre for Transfusion Research, Department of Medicine, McMaster University, Hamilton, ON, Canada. Department of Medicine, University of Toronto, Toronto, ON, Canada. Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada. Faculty of Medicine, Université de Montréal, Montreal, QC, Canada. Division of Hematology, University of Alberta, Edmonton, AB, Canada. Department of Medicine, University of Ottawa, Ottawa, ON, Canada. Department of Hematology, HagaZiekenhuis, The Hague, Netherlands. Department of Hematology, HagaZiekenhuis, The Hague, Netherlands; Department of Hematology, University Medical Centre Groningen, Groningen, Netherlands. Department of Medicine, McMaster University, Hamilton, ON, Canada. Division of Hematology, Mayo Clinic College of Medicine, Jacksonville, FL, USA. McGill University Health Centre, Montreal, QC, Canada. Michael G DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada; McMaster Centre for Transfusion Research, Department of Medicine, McMaster University, Hamilton, ON, Canada; Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada.