Factors associated with successful mobilization of peripheral blood progenitor cells in 200 patients with lymphoid malignancies

Peripheral blood progenitor cells (PBPC) were mobilized and harvested in 200 patients treated for non-Hodgkin's lymphoma ( n  = 148), Hodgkin's disease ( n  = 22) and multiple myeloma ( n  = 30). The variables predicting the collection of a minimal (>2.5 × 10⁶/kg) or a high (>10 × 10⁶/kg) CD34⁺ cell count were analysed. Patients were mobilized with haemopoietic growth factors following either standard chemotherapy ( n  = 49) or high-dose cyclophosphamide, given alone ( n  = 55) or combined with high-dose VP16 ( n  = 86). 10 patients received haemopoietic growth factors only. The first mobilization resulted in a PBPC harvest with enough CD34⁺ cells in 179/200 patients (90%). High-dose cyclophosphamide, with or without VP16, did not mobilize a higher progenitor cell yield than standard chemotherapy. When performing multiple regression analysis in the 190 patients who received chemotherapy-containing mobilization, only the number of previous chemotherapy regimens and the exposure to fludarabine predicted for a failure to collect a minimal PBPC count ( P  = 0.06 and 0.0008 respectively). The target to collect a high CD34⁺ cell count was negatively associated with the number of previous chemotherapy regimens ( P  = 0.002). When only non-Hodgkin's lymphoma patients were considered for multivariate analysis, low-grade histology with fludarabine appeared to be associated with poor PBPC cell yield ( P  = 0.08 and 0.005 respectively). This data confirms that PBPC harvest should be planned early in the disease course in transplant candidates, and can be obtained after a standard course of chemotherapy.