PBSC COLLECTION AFTER HIGH-DOSE CHEMOTHERAPY FOLLOWED BY G-CSF IN PATIENTS WITH MALIGNANCIES - ANALYSIS OF RESULTS REGARDING FACTORS AFFECTING THE YIELD OF HEMATOPOIETIC PROGENITORS

High-dose non ablative chemotherapy followed by growth factors efficie ntly mobilizes and amplifies Pheripheral Blood stem Cells (PBSC). Cyto fluorimetric PBSC monitoring reduces the number of leukapheresis neede d to collect sufficient amounts of progenitors to restore hemopoiesis after myeloablative therapy. Twenty-eight patients, affected by lympho proliferative disorders, were primed with non myeloablative chemothera py followed by G-CSF 5 mu g/kg/die subcutaneously, until leukapheresis . A total number of 90 leukaphereses was performed (median: 3 per pati ent) using blood cell separator CS 3000 Plus Baxter; we collected 1+/- 0.8x10(8)/kg mononuclear cells (MNC), 6+/-9 x 10(4)/kg CFU-GM and 4+5 x 10(6) CD34+ cells for each procedure. The statistical analysis showe d that the number of progenitors collected was dependent on the age, n umber and type of previous chemotherapies and interval between the las t chemotherapy and the priming; the type of priming, type and status o f disease, sex, and bone marrow involvement were not significant. Dura tion of neutropenia after megachemotherapy was very short; in two case s platelet support was necessary and only two patients needed hospital ization. Our experience shows that high-dose non ablative chemotherapy followed by G-CSF is safe and yields large amounts of PBSC; several f actors influence the quality of collections mainly regarding age and t he previous treatment.