Clinical analysis of sub-standard dose of donor stem cell infusion mobilized by granulocyte colony-stimulating factor in treatment of relapsed acute leukemia after allogenic hematopoietic stem cell transplantation

Abstract

Objective To investigate the clinical effect and prognosis of sub-standard dose of donor stem cell infusion(DSI) mobilized by granulocyte colony-stimu1ating factor(G-CSF) in patients with relapsed acute leukemia (AL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods From January 2010 to April 2017, a total of 17 patients with relapsed AL after allo-HSCT in Department of Hematology, the First Affiliated Hospital of Xi′an Jiaotong University were included in the study. They were divided into DSI combined chemotherapy group (n=7) and chemotherapy alone group (n=10) according to different treatment after relapse. The basic clinical data of patients with relapsed AL after allo-HSCT were collected by retrospective analysis. The infusion dose of DSI, treatment results, adverse reactions and survival outcomes were observed in both groups. Kaplan-Meier method was used to draw the overall survival (OS) and survival after first relapse (SAR) curves of two groups. The OS and SAR rate were compared by Log-rank test between two groups. This study protocol was approved by the ethics committee of the First Affiliated Hospital of Xi′an Jiaotong University (Approoal No. XJTU1AF2010LSL-020). Informed consents were obtained from all patients before treatment. Results ① The median age of patients in DSI combined chemotherapy group was 28 years (11-49 years), 3 cases were positive in fusion gene, and 6 cases were achieved complete remission(CR)1 before transplantation, none of them had graft versus host disease(GVHD). The median age of patients in chemotherapy group was 22 years (15-37 years). The fusion gene was positive in 4 cases, and 2 cases had GVHD. ② In DSI combined chemotherapy group, 5 patients received single DSI treatment after conventional chemotherapy, and 2 patients received DSI treatment in every two weeks. Three patients (3 / 7) achieved CR. There were 4 patients with grade Ⅰ ~Ⅱ aGVHD of skin and liver, 3 patients with grade Ⅳ myelosuppression and pneumonia. Up to the end of follow-up, 1 patient survived and 6 died in DSI combined chemotherapy group. ③In the chemotherapy group, 3 patients (3 / 10) achieved CR after treatment. Up to the end of follow-up, 4 patients survived and 6 patients died. ④ The 1-year and 3-years OS rates of patients in DSI combined chemotherapy group were 57.1% and 19.0%, respectively, and those of patients in chemotherapy group were 66.7% and 17.8%, respectively. There were no significant differences between two groups (χ2 = 2.122, 0.136; P=0.58, 0.68). There was no significant difference in 1-year SAR rate between two groups (41.3% vs 29.8%; χ2=3.165, P=0.43). Conclusions The combination of G-CSF mobilized sub standard dose DSI with chemotherapy may improve the CR rate of patients with relapsed AL after allo-HSCT. Reducing dose of DSI may reduce the incidence of severe GVHD without affecting the therapeutic efficacy and graft versns leukemia(GVL) effect. Key words: Leukemia; Hematopoietic stem cell transplantation; Recurrence; Hematopoietic stem cell mobilization; Donor stem cell infusion