1. Department of Hematology/Oncology, Bonn, University Hospital Bonn, Germany;
2. Internal Medicine V, Hematology/Oncology, Medical University Innsbruck, Innsbruck, Austria;
3. Centre for Bone Marrow and Blood Stem Cell Transplantation, Deutsche Klinik für Diagnostik, Wiesbaden, Germany; and
4. Department I of Internal Medicine, University Hospital Cologne, Cologne, Germany