title: Delayed rejection after initial engraftment in non-myeloablative bone marrow transplantation.
abstract: Non-myeloablative bone marrow transplantation (NM-BMT) is a newly developed therapeutic strategy for malignant and non-malignant hematological diseases, as well as immunotherapy-responsive solid tumors. The graft-versus-leukemia (GVL) or graft-versus-tumor (GVT) effect is the major therapeutic effect of this procedure, which also decreases transplant-related mortality (TRM) while remaining relatively safe for older patients. Graft rejection may be a main concern for NM-BMT in high-risk patients such as unrelated-donor BMT and elder recipients, however, very few literatures have mentioned this issue. Here we report 2 cases of NM-BMT where delayed rejection developed after initial engraftment. The first case was a victim of chronic myelogenous leukemia (CML) in chronic phase receiving HLA-matched unrelated-donor (MUD) BMT using the non-myeloablative regimen (fludarabine/busulphan/ATG). Chimerism study after BMT revealed successful initial engraftment, however, pancytopenia developed since day +38. Bone marrow examination on day +47 revealed only 15% of donor-type cells, with subsequent salvage haploidentical BMT failing to engraft. The patient expired on day +71. The second case was a victim of myelodysplastic syndrome, received HLA-matched sibling-donor allogeneic BMT using the same regimen as for Case 1, with successful initial engraftment proved by chimerism study. Pancytopenia was noted since day +124, and chimerism study on day +127 revealed only 25% of donor-type cells. The patient expired on day +151. We recommend that the suitability of NM-BMT for high-risk patients such as unrelated-donor BMT and elder recipients needs further studies to confirm.
authors.affiliation: Division of Medical Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Muh-Hwa
authors.initials: MH
authors.lastname: Yang
authors.forename: Tzeon-Jye
authors.initials: TJ
authors.lastname: Chiou
authors.forename: Ta-Chung
authors.initials: TC
authors.lastname: Chao
authors.forename: Liang-Tsai
authors.initials: LT
authors.lastname: Hsiao
authors.forename: Po-Min
authors.initials: PM
authors.lastname: Chen
mesh_terms: D000328:Adult; D016026:Bone Marrow Transplantation / Q000379:methods*; D005260:Female; D006084:Graft Rejection; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000601:surgery; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000601:surgery; D013997:Time Factors; D019172:Transplantation Conditioning / Q000379:methods