SUCCESSFUL COLLECTION OF PERIPHERAL-BLOOD PROGENITOR CELLS IN PATIENTS WITH ACUTE MYELOID-LEUKEMIA FOLLOWING EARLY CONSOLIDATION THERAPY WITH GRANULOCYTE-COLONY-STIMULATING FACTOR-SUPPORTED HIGH-DOSE CYTARABINE AND MITOXANTRONE

We evaluated the feasibility of collecting peripheral blood progenitor cells (PBPC) in patients with acute myeloid leukaemia (AML) following two cycles of induction chemotherapy with idarubicin, cytarabine and etoposide (ICE), and one cycle of consolidation therapy with high-dose cytarabine and mitosantrone (HAM). Thirty-six patients of the multice ntre treatment trial AML HD93 were enrolled in this study and a suffic ient number of PBPC was harvested in 30 (83%). Individual peak concent rations of CD34(+) cells in the blood varied (range 13.1-291.5/mu l: m edian 20.0/mu l). To reach the target quantity of 2.5 x 10(6) CD34(+) cells/kg, between one and six (median two) leukaphereses (LP) were per formed. The LP products contained between 0.2 x 10(6) and 18.9 x 10(6) CD34(+) cells/kg (median 1.2 x 10(6)/kg). Multivariate analysis showe d that the white blood cell count prior to HAM and the time interval f rom the start of HAM therapy to reach an unsupported platelet count >2 0x10(9)/l were predictive for the peak value of CD34(+) cells in the b lood during the G-CSF stimulated haematological recovery, In 16 patien ts an intraindividual comparison was made between bone marrow (BM) and PBPC grafts. Compared to BM grafts, PBPC grafts contained 14-fold mor e MNC, 5-fold more CD34(+) cells and 36-fold more CFU-GM. A CD34(+) su bset analysis showed that blood-derived CD34(+) cells had a more immat ure phenotype as indicated by a lower mean fluorescence intensity for HLA-DR and CD38. In addition, the proportion of CD34(+)/Thr-1(+) cells tended to be greater in the PBPC grafts, The data indicate that suffi cient PBPC can be collected in the majority of patients with AML follo wing intensive double induction and first consolidation therapy with h igh-dose cytarabine and mitoxantrone.