Richard Schäfer1, Karen Bieback2. 1. Institute for Transfusion Medicine and Immunohaematology, German Red Cross Blood Donor Service Baden-Württemberg-Hessen gGmbH, Goethe University Hospital, Frankfurt am Main. 2. Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, Heidelberg University, German Red Cross Blood Donor Service Baden-Württemberg-Hessen gGmbH, Mannheim, Germany.