HLA-Haploidentical Stem Cell Transplantation for Malignant Hematological Diseases Using G-CSF Mobilized Bone Marrow and Peripheral Blood Stem Cells

Allogeneic haematopoietic stem cell transplantation (HSCT) has been used to treat malignant hematological diseases. For patients who do not have a matched sibling donor or a matched unrelated donor (MUD) for transplantation, an eligible HLA-haploidentical donor can be identified rapidly in nearly all cases. However, HLA-haploidentical BMT has been associated with significant risks of complication, such as graft rejection and severe GVHD and infection.

Thirty eight consecutive patients with malignant hematological diseases received HLA-haploidentical stem cell transplant from April 2008 to June 2010. Eligible patients were 9– 48 years of age with acute myeloid leukemia (n=10),acute lymphocytic leukemia (n=17), myelodysplastic syndrome(n=5), chronic myeloid leukemia (n=4), non Hodgkin lymphoma (n=2). Transplantation conditioning consisted of Ara-C (4 g/m2/d, i.v.) on day -10 and -9, Bu (9.6mg/kg i.v. in 12 doses) on day -8, -7 and -6, Cy (1.8 g/m2/d, i.v.) on day -5 and -4, Me-CCNU (250 mg/kg, i.v.) on day -3, and ATG (2.5 mg/kg/d i.v.) on day -5 to -2. The prophylaxis of aGVHD consisted of cyclosporine A (CsA), mycophenolate mofetil (MMF), and short-term methotrexate. Donors were primed with rhG-CSF (7.5 mg/kg per day) injected subcutaneous (s.c.). Bone marrow cells and peripheral blood stem cells(PBSC) were harvested in nineteen donors, and only PBSC were harvested in the other 19 donors.

Primary engraftment was achieved in all patients. All the patients achieved complete donor chimerism in the peripheral blood before day +28. Seven patients (18.4%) had grade I aGVHD, ten (26.3%) had grade II aGVHD, four(10.5%) had grade III aGVHD and four (10.5%) had grade IV aGVHD. II-IV aGVHD occurred in nine patients treated with bone marrow cells and PBSCs, the same number patients suffered from II-IV aGVHD treated with only PBSCs. Transplant related mortality within 100 days after transplantation was 15.8%. At a median follow-up of 10 months (range 2–28months), the overall survival was 68.4%.

Haploidentical stem cell transplantation is relatively safe and efficient for the patients who have no HLA matched donors.The results require to confirm and show that G-BM combined with PBSC or G-PBSC from haploidentical family donors have equal effect.

No relevant conflicts of interest to declare.