Predictive factors affecting mobilization and peripheral blood stem cell (PBSC) collection using single apheresis (SA) for rescuing patients after high-dose chemotherapy (HD.CHE) in various malignancies.

We have investigated factors that affect the efficiency of single apheresis (SA) before transplant and define groups of patients that may require more than one collection for hematologic support. A consecutive series of 56 patients with hematologic malignancies and solid tumours had peripheral blood stem cells (PBSC) collected following mobilization with colony-stimulating factors (CSF) alone or after conventional chemotherapy (CHE) or high-dose cytoxan (HD.CY) followed by CSF. The efficiency of SA was assessed by total mononuclear cell number (MNC) in the harvest, CD34+ cells and colony-forming units (CFU). Linear regression analysis was performed to determine factors that affect SA yield as assessed by the above parameters. Thirty-five patients were mobilized once, 13 patients twice, six patients required three, one required four and one required five aphereses. Suboptimal mobilization and collection by SA occurred in patients with extended previous radiotherapy (RT) and patients older than 50 years. The number of CHE cycles given in the past also had an adverse effect on SA efficiency. In contrast, disease status, bone marrow infiltration by malignant cells, type of CHE, time since last CHE and mobilization regimen used were not significantly related to the collection efficiency by SA. Age, extent of previous RT and amount of CHE given prior to mobilization define the patients who require more than one SA course for support regardless of the underlying disease, BM status or mobilization regimen used. In such patients a plan for multiple aphereses should be scheduled in advance.