Factors affecting both peripheral blood progenitor cell mobilization and hematopoietic recovery following autologous blood progenitor cell transplantation in multiple myeloma patients: a monocentric study.

The aim of the study was to analyze the factors influencing peripheral blood progenitor cell (PBPC) collection after high-dose cyclophosphamide (HDCYC) (7 g/m2) and hematopoietic recovery after autologous transplantation of HDCYC-mobilized PBPC (ABPCT) in 116 patients with aggressive multiple myeloma (MM). Following HDCYC 74 patients received hematopoietic growth factors (HGF), either G-CSF (n = 19) or GM-CSF (n = 55). All the patients were subsequently planned to undergo ABPCT. PBPC collection was possible for 106 patients. The most important prognostic factor for collection of more than 25 x 10(4) CFU-GM cells/kg and 2 x 10(6) CD34+ cells/kg was the use of HGF (P = 0.002 and 0.009, respectively). Previous use of an alkylating agent, response to treatment before HDCYC, and interval between diagnosis and HDCYC were also significant factors (P = 0.004, 0.025 and 0.001, respectively). The number of CFU-GM cells infused was the most important parameter for rapid and complete hematological recovery after ABPCT (P < 0.0001). Thus the use of HGF post-HDCYC is the major factor which, associated with reduced time between diagnosis and HDCYC and the use of an alkylating agent, could increase the numbers of hematopoietic progenitors collected, and subsequently improve hematopoietic recovery following ABPCT in MM patients.