1. Department of Pathology, Division of Transfusion MedicineBrigham and Women's Hospital and Harvard Medical School Boston Massachusetts
2. Ottawa Hospital Research InstituteUniversity of Ottawa Ottawa Ontario
3. Department of Pathology, Blood Transfusion ServiceMassachusetts General Hospital and Harvard Medical School Boston Massachusetts
4. Department of Pathology, Histocompatibility LaboratoryMassachusetts General Hospital and Harvard Medical School Boston Massachusetts