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.

Peripheral blood progenitor cell (PBPC) transplantation with a single apheresis in patients with lymphoma, myeloma and solid tumors.

The aim of this study was to investigate if a single apheresis after peripheral blood progenitor cell (PBPC) mobilization can be used to rescue patients receiving high dose chemotherapy (HD.CHE) as treatment for an underlying malignancy. Eighteen consecutive patients who were admitted to the transplant unit for treatment were leukapheresed following mobilization with one of the following protocols: group I: rHuG-CSF alone, group II: conventional chemotherapy (C.CHE) + rHuG-CSF or rHuGM-CSF and group III: high dose cytoxan (HD.CTX) + rHuG-CSF. The optimal day for leukapheresis was determined by following white blood cell counts (WBC), mononuclear cell counts (MNC) and CD34+ cell counts daily. Granulocyte-macrophage colony-forming cells (GM-CFC) assay was performed at the leukapheresis product and prior to reinfusion. All patients proceeded directly to ablative therapy according to their underlying malignancy. PBPC from single apheresis were reinfused to all patients and cytokines started 24 h after infusion. Hematologic recovery after HD.CHE was the parameter used to ensure successful engraftment. We have been able to recover adequate number of PBPC for transplantation with a single apheresis in all patients. The number of infused cells were for groups I, II and III: (1) median number of MNC 4.7, 3.58 and 2.79 x 10(8)/kg, respectively (2); median number of CD34+ cells 4.4, 2.8, 2.7 x 10(6)/kg, respectively. The median apheresis day was 6, 16 and 16, respectively. Recovery times to granulocyte count > 0.5 x 10(9)/ L was 9 d (range 9-12) and to platelets > 20 x 10(9)/L was 12 d (range 1-135); 17/18 patients have engrafted successfully independent of the mobilization method used. These data suggest that sufficient PBPC can be harvested at a single leukapheresis for hemopoietic rescue after myeloablative therapy. Rapid hematologic recovery occurs when cytokines alone after conventional or HD.CHE are used for mobilization. Results of collection products and hematopoietic recovery are independent of the mobilization technique used.