The purpose of this study was to investigate the clinical efficacy against acute leukemia by transplantation of nonmyeloablative allogeneic peripheral blood stem cells from unrelated donor (URD NAPBSCT). One patient with acute lymphoblastic leukemia received URD NAPBSCT in our hospital. The donor cells were full engafted, and grade Ⅱ skin aGVHD and interstitial pneumonia were developed. The results showed that URD NAPBSCT is an effective new method for the treatment of acute leukemia.

To evaluate the effects of donor stem cell infusion (DSI) in patients after nonmyeloablative allogeneic peripheral blood stem cell transplantation( NAPBSCT),6 patients were infused donor stem cell in+7d～+90d consisting of MNC (0.6～7.6)?10 8 /kg, CD34 + cells (0.3～3.4)?10 6 /kg,CD3 + cells (0.3～5.1)?10 8 /kg.The results showed that 5/6 patients had definite effects in promoting donor chimeras after DSI,of these 3 achieved full donor chimeras following mixed chimeras ;4/6 have graft versus leukemia(GVL)effects.No hematopoiesis aplasia was found, and only one Ⅳdegree aGVHD developed related with DSI. It was concluded that DSI have definite GVL effects and can convert mixed chimeras to full chimeras without causing GVHD and severe hematopoietic aplasia.