[Clinical study on hematopoietic reconstitution in patients with leukemia by haploidentical bone marrow transplantation].

To investigate the properties of haploidentical donor-derived bone marrow engraftment and hematopoietic reconstitution in patients received bone marrow transplantation, 15 patients with leukemia received bone marrow grafts without T cell depletion from their family donors of those with 2-3 mismatched loci of HLA antigens. The donors were given G-CSF 250 micro g/day for 7 days prior to marrow harvest. All patients were treated with conditioning regimens consisting of high-dose of Ara-C, cyclophosphamide, and total body irradiation. A four-agent based GVHD prophylaxis was used as cyclosporine A, MTX, ATG and mycophenolate mofetile (MMF). Donor engraftment was evaluated as identification of HLA locus, chromosome karyotype, DNA fingerprinting, blood type and other parameters such as occurrence of GVHD, recovery of peripheral blood cell counts as well as normal myelogram. The results showed that successful and stable engraftment was established in all patients. The median time of granulocyte counts > 0.5 x 10(9)/L and platelet > 20 x 10(9)/L was 18 (13-23) and 22 (16-32) days, respectively. One of the patients relapsed despite the bone marrow chimerism appearing after transplantation. The grade I acute GVHD occurred in 8 and grade II-IV in 5 of the 15 patients. Of the patients, 7 received marrow grafts from donors of opposite sex were identified for donor engraftment by chromosome analysis, 4 by blood typing, 7 with HLA locus analysis and 1 with DNA fingerprinting. In conclusion, HLA haploidentical bone marrow transplantation is feasible with a series of management including mobilization with G-CSF in donors, intensive conditioning and proper immunosuppressants, which enable the allo-transplants to stride across the immunological barrier.