Factors affecting stem cell mobilization for autologous hematopoietic stem cell transplantation

High-dose chemotherapy with autologous stem cell transplantation (ASCT) is curative treatment in various hematologic malignancies. Mobilization and collection of peripheral blood stem cell is the essential part of ASCT. The aim of this study was to evaluate the effectiveness of various mobilization regimens, determine the risk factors associated with mobilization failure (MF). We also investigated whether iron overload, which has an adverse impact on various aspects of HSCT including overall survival had any impact on mobilization kinetics. A total of 118 consecutive patients were included in this study. The rate of MF was 11.8 % with the first mobilization regimen. Frequency of MF was higher in lymphoma (P < 0.001) patients and in those receiving G-CSF alone (P= 0.01). Peripheral CD34+ cell count (P < 0.001), bone marrow cellularity (P < 0.001), reticulin fibrosis (P < 0.05) were significantly lower whereas serum ferritin levels (P = 0.06) tended to be higher in patients with MF. CD34+ cell count of the first apheresis product was positively correlated with the white blood cell count (P < 0.05; r = 0.232), platelet count (P = 0.01; r = 0.233), peripheral CD34+ cell count (P < 0.001; r = 0.704) and the grade of bone marrow reticulin fibrosis (P < 0.001; r = 0.366). Serum ferritin levels were negatively correlated with maximum peripheral CD34+ cell count (P = 0.02; r = -0.216) and the CD34+ cell count in the first product (P = 0.05; r = -0.183). Platelet count (P = 0.03; β = 0.262), peripheral CD34+ cell count (P = 0.02; β=0.279) were the two variables which remained to be significant in multivariate analysis. Predicting the poor mobilizers with the platelet count for instance may reduce the risk of MF by using more effective regimens in advance.