BACKGROUND: Although haploidentical transplantation has become a clinical reality for acute myeloid leukemia (AML) patients lacking a HLA compatible donor due to several encouraging reports, it is still considered as one of an experimental treatment modalities.
METHODS: Eleven patients received stem cell transplantation from family donors having mismatched HLA haplotypes. For patients who were planned for 2 or 3 major antigens mismatch transplantation, their conditioning regimens included total-body irradiation (TBI), intravenous busulfan, antithymocyte globulin, and fludarabine in 6 patients and non-TBI containing regimen in 2 patients. For 3 patients with 1 major antigen mismatch sibling donor, we used 3 different regimens according to the patients´ condition. The median number of infused CD34+ cells were 15.4x10(6)/kg (range, 8~21.2).
RESULTS: Ten patients who were followed up for at least median 4 months (range, 17 days-15 months) showed stable engraftment. Patients who received haploidentical transplantation in first or second complete remission (CR), all showed continuous CR within our study period and showed no acute graft-versus-host disease or transplant-related mortality during 100 day posttransplant. Three of 5 patients who were in relapse or refractory state finally died in relapse. Two of 3 patients who received the full haplotype mismatch transplantation in CR died after 4 months posttransplant due to critical infections associated with delayed immune recovery.
CONCLUSION: Our experience suggests that haploidentical transplantation is at least, in part, feasible or desperate treatment for patients with high-risk AML in CR. We need further stable plan to enhance the immune recovery for these patients as soon as possible.

Keywords: Haplotype mismatch transplantation, CD34+ cells, Acute myeloid leukemia