Haplo-Identical Allogeneic Stem Cell Transplantation Using GCSF-Mobilized Marrow Plus Blood Stem Cells from Parent Donors for Children with High-Risk Leukemia.

Increasing number of patients in China have difficulty of finding sibling donors due to limited number of siblings. We therefore explored the feasibility using haploidentical parent donors for allogeneic hematopoietic stem cell transplantation. Eight leukemia patients were studied in our hospital. These included 2 CML-BC, 2 MDS-RAEB, 3 relapsed ALL and 1 relapsed AML. The median age was 12 (7–17). GCSF- mobilized bone marrow and peripheral blood stem cells were collected from parents (1 to 3 locus mismatched). The conditioning regimen consisted of fludarabine (30mg/m2/d x5), bulsulfan (4mg/kg/d x3) and cyclophosphamide (50mg/kg/d x2). Cyclosporin A, mycophenolate mofetil, methotrexate, and ATG were used for GVHD prophylaxis. The total number of CD34+ cell in the grafts ranged between 5–10 x 106/kg. The median follow- up was 13 months (6–24). One patient failed to engraft, the other 7 patients achieved full donor chimerism at day 28. The incidence of acute GVHD (grade II-IV) was 57.1% (4 of 7). The incidence of chronic GVHD of limited stage occurred in the same 4 patients. One patient died of lung complication at 17th month, another patient with CML-BC relapsed 10 months after transplantation. The rest 6 patients are alive without disease. These results suggested that parents could be considered as stem cell donors in the absence of alternative donors for young patients with high-risk diseases. GCSF-primed bone marrow plus peripheral blood stem cells might be beneficial to reduce the risk of GVHD for leukemia children in China. More patients are needed to further study this approach.