1. Department of Hematology, West German Cancer Center, University Hospital Essen, University of Duisburg-Essen, Essen, Germany;
2. Department of Anesthesiology and Intensive Care, University Hospital Essen, Essen, Germany;
3. Department of Molecular Biology, University of Duisburg-Essen, Essen, Germany;
4. Department of Bone Marrow Transplantation, West German Cancer Center, University of Duisburg-Essen, University Hospital Essen, Essen, Germany;
5. Department of Pediatrics III, University Children’s Hospital Essen, University of Duisburg-Essen, Essen, Germany;
6. Rheinisch-Westfälisches Institut für Wirtschaftsforschung, Essen, Germany;
7. Institute for Transfusion Medicine, University Hospital Essen, Essen, Germany;
8. Department of Internal Medicine V, Hematology, Oncology and Rheumatology, University Hospital Heidelberg, Heidelberg, Germany