Background: Autologous peripheral blood stem cell transplantation (PBSCT) has been used as a major treatment strateg for malignant lymphoproliferative disorder. The number of CD34 positive cells in the harvested product is a very important factor for achieving successful transplantation. We studied the factors that can predict the number of CD34 positive cells in the harvested product of multiple myeloma (MM) and Non-Hodgkin's lymphoma (NHL) patients after mobilizing them with chemotherapy plus G-CSF.
Methods: A total of 69 patients (MM 25 patients, NHL 44 patients) with malignant lymphoproliferative disorder had been mobilizedwith chemotherapy and granulocyte colony-stimulating growth factor from January, 2003 to July, 2008. We analyzed the clinical characteristics, the peripheral blood (PB) parameters and the number of CD34 positve cells in the PB and their correlation with the yield of PBPCs collected from the mobilized patients.
Results: The total number of leukapheresis sessions was 134 (mean: 1.94 session per patient), and the mean number of harvested CD34 positive cell per patient was 12.47×10⁶/kg. The number of harvested CD34 positive cells was correlated with the patient's height, the number of peripheral blood hematopoietic progenitor cells (HPC) and the number of PB CD34 positive cells at the harvest (P＜0.05). But the number of PB CD34 positive cell was the only significant factor for the quantity of harvested CD34 positive cells on the linear regression analysis (P＜0.05). More than 23.7/ՌL PB CD34 positive cells were needed to harvest 3×10⁶/kg CD34 positive cells, according to the ROC curve (P＜0.05).
Conclusion: The number of PB CD34 positive cells (≥23.7/ՌL) at the harvest might be the predictor of harvesting more than 3×10⁶/kg CD34 positive cell for autologous PBSCT in patients with malignant lymphoproliferative disorder.

Keywords: CD34 positive cell, Mobilization, Harvest