[1] National and Kapodistrian University of Athens,Second Department of Internal Medicine, ATTIKO General University Hospital
[2] Evangelismos General Hospital,Department of Hematology and Bone Marrow Transplantation
[3] Aghia Sophia Children Hospital,Department of Bone Marrow Transplantation
[4] National and Kapodistrian University of Athens,Department of Clinical Microbiology, ATTIKO General University Hospital
[5] National and Kapodistrian University of Athens,Forth Department of Internal Medicine, ATTIKO General University Hospital