Synegenic Peripheral Blood Stem Cell Transplantation For Aplastic Anemia

Synegenic peripheral blood stem cell transplantations ( Sn-PBSCTs ) were performed on 2 patients with aplastic anaemia (AA). The graft rejection occurred at the 4th month after transplantation in one patient . In order to explore the pathogenesis of AA , two cases above are discussed .Aplastic anemia can be cured through Stem cell transplantaton. First, G-CSF 600ug/dwas given to mobilize donor peripheral blood stem cells (PBSCs). Two phereses were performed on donors at the 5th and 6th days after mobilization. 3.13×108Ag and 8.80×108/ kg MNCs were harvested respectively. After conditioning regimen with cyclophosphamide 180mg/kg, given in three divided doses over at -4- -3,-2 days, the MNCs were infused at 0 day. The ANC, hemoglobin and platelet were respectively 1.0×109/L, 67g/L, 52×109/L and 1.2×109/L, 765g/L , 59×109/L at the 14th day , 2.3×109/L, 106g/L, 152×109/Land 2.5×109/L, 115g/L , 259×109/L in SAA patient and CAA patient respectively. However, the blood cell decreased at the fourth month in the SAA patient because of later graft rejection. The parameters maintained stable until now. Untreated blood transfusions before PBSCT, conditioning regimen and the uterus tumor may be responsible for the graft rejection. The improved survival of patients with aplastic anemia who were treated by BMT or PBSCT has been due to decreased incidences of both graft rejection and GVHD. The decline in rejection rates resulted from the more judicious use of transfusions before marrow grafting, the removal of sensitizing white blood cells from the products. As more and more patients become long-term survivors, the problems of long-term sequelae from the conditioning regimen and immunosuppression must be considered, especially secondary cancer. CY/ATG appears preferable to irradiation-based regimen.From the two patients treated with synegenic PBSCT, possible got as follows: 1. Potential mechanisms of aplastic anemia including intrinsic defects ofhaematopoietic stem cells and abnormal humoral and cell immune of hematopoiesis.2. Severe aplastic anemia can be cured by haematopoietic stem cell transplantation. Synegenic HSCT is the best choice for severe aplastic anemia and chronic aplastic anemia.3. PBSCT has been successfully used as replacement therapy for bone marrow transplantation.4. The more judicious use of transfusions before marrow grafting and careful choice of the conditioning regimens are important to HSCT.