Objective: To investigate the outcomes and problems in unrelated bone marrow transplantation (URD-BMT).
Methods: 19 patients received URD-BMT in our institute from August 1998 to February 20, 2001. The diagnoses included chronic myelogenous leukemia (CML) (n = 9), acute lymphoblastic leukemia (ALL) (n = 6), acute myelogenous leukemia (AML) (n = 2), MDS-RAEB (n = 1) and beta-thalassemia major (n = 1). 19 pairs were HLA-A, HLA-B, HLA-DR matched with low resolution technique; 8 of them were HLA-A, B or DRB1 mismatched with high resolution technique. 2 patients received a TBI conditioning regimen, the other 17 received BUCY or modified BUCY regimen. Bone marrow was infused to 18 recipients via aorta and one through intravenous route. As graft versus host disease (GVHD) prophylaxis, all patients received CSA and MTX, 9 patients received ATG, 1 patient received CD(3)/CD(25) and 7 patients received mycophenolate mofetil. T-cell depletion technique was applied in one patient. Statistics Kaplan-Meier plots for time-dependent analysis (survival, acute GVHD and engraft). Fisher' exact test was used for univariate analysis of risk factors.
Results: Apart from 2 patients who were under observation and one patient with CML suffered from late rejection. 16 out of the 19 patients had all been persistently engrafted. Relapse happened on day 60 in one patient who had advanced refractory ALL. Early infection within 5 weeks after BMT with discernable pathogens was documented in 5 patients. CMV infection occurred in 10 patients. 13 out of the 19 patients have survived. The disease free survival rate was 58.3%. The cumulative incidence of acute GVHD grades II approximately IV was 53.0%.
Conclusion: Even if the results of using HLA identical unrelated donor marrow are encouraging, the high transplantation related mortality due to infection and GVHD is a major challenge. It is not likely that this technique will be extensively used. However, in cases of high risk acute leukemia or chronic myelogenous leukemia without appropriate related donor, URD-BMT might be a therapeutic measure.