1. José Carreras Research Laboratory, Department of Hematology and Cell Therapy, Faculty of Medicine, University of Leipzig, Johannisallee 32A, 04103 Leipzig, Germany
2. Armauer Hansen Research Institute, Addis Ababa P.O. Box 1005, Ethiopia
3. College of Health Sciences, Addis Ababa University, Addis Ababa P.O. Box 1176, Ethiopia
4. Laboratory for Transplantation Immunology, University Hospital Leipzig, Johannisallee 32, 04103 Leipzig, Germany
5. Medical Laboratory Scienec, Madda Walabu University, Bale Robe P.O. Box 247, Ethiopia