Successful allogeneic bone marrow retransplantation with the same donor after graft rejection: application of a modified conditioning regimen.

A 26-year-old man with severe aplastic anemia was treated with high-dose Cyclophosphamide followed by the infusion of bone marrow cells from his HLA-identical sister. After initial intake of the graft, rejection ensued by day 46 which was followed by a permanent complete aplasia. After 4 months, bone marrow retransplantation with the same donor was attempted after a more intensive conditioning regimen. This led to permanent engraftment with rapid normalization of the blood counts lasting now for over 12 months. The patient has since remained in excellent clinical condition without signs of graft-versus-host disease.