1. German Red Cross Blood Service Baden-Württemberg-Hessen, Institute for Transfusion Medicine and Immunohematology, Frankfurt am Main, Germany;
2. Faculty of Biological Sciences, Goethe University, Frankfurt am Main, Germany;
3. Goethe University School of Medicine, Institute for Transfusion Medicine and Immunohematology, Frankfurt am Main, Germany; and
4. Division of Hematology, Department of Medicine, University of Washington, Seattle, WA