Circulating progenitor cell collection: Experience from 275 leukaphereses in various malignancies and in healthy donors

Background. Blood cell transplantation has become a new type of support in high-dose chemotherapy (HDC) for several oncologic and hematologic diseases. Over the last few years the demand for circulating progenitor cell (CPC) collection by blood cell separators has grown dramatically, and transfusion services must manage new CPC programs. Materials and Methods. A protocol for optimizing the collection and clinical use of CPC is described. The results of 275 harvestings were studied: 128 patients were divided into 5 groups according to tumor type (A: breast cancer; B: Hodgkin's disease; C: non-Hodgkin lymphoma; D: multiple myeloma; E: various solid tumors). An additional group (F) consisted of 11 healthy donors. Factors affecting collection (mobilizing regimen or previous radiation therapy) and side effects were investigated. Results. The mean values of mononuclear cells (MNC×107/kg) and CD34+ cells (×106/kg) collected per leukapheresis in the 6 respective groups were: 31.4 and 4.6 in group A; 26.4 and 3.4 in group B; 21.8 and 5.8 in group C; 24.6 and 2.4 in group D; 26.8 and 2.9 in group E; 60 and 6 in group F. Previous chemotherapy and/or radiation therapy were the main factors influencing CPC harvesting. The different chemotherapy regimens employed demonstrated no significant differences in their mobilizing efficacy. Side effects related to leukapheresis were few (2.3% of the procedures) and manageable. Conclusions. CPC collection is feasible in a wide range of clinical situations. Careful clinical evaluation of patients, accurate monitoring of progenitor cell release and collection timing are important for obtaining a sufficient number of CPC for hemopoietic recovery. Previous chemotherapy and radiotherapy are the main factors influencing CPC harvests. The mobilizing regimens employed showed no substantial differences in their efficacy.