Peripheral blood stem cell transplantation as an alternative to autologousmarrow transplantation in the treatment of acute myeloid leukemia?

The clinical use of autologous marrow transplantation in acute myeloid leuk emia (AML) has been hampered by the inability to collect adequate numbers o f cells after remission induction chemotherapy and the notably delayed hema topoietic regeneration following autograft reinfusion. Here we present a st udy in which the feasibility of mobilizing stem cells was investigated in n ewly diagnosed AML, Among 96 AML patients, 76 patients (79%) entered comple te remission. Mobilization was undertaken with low dose and high dose sched ules of G-CSF in 63 patients, and 54 patients (87%) were leukapheresed. A m edian of 2.0 x 10(6) CD34(+) cells/kg (range 0.1-72.0) was obtained in a me dian of three leukaphereses following a low dose G-CSF schedule (150 mu g/m (2)) during an average of 20 days. Higher dose regimens of G-CSF (450 mu g/ m(2) and 600 mu g/m(2)) given during an average of 11 days resulted in 28 p atients in a yield of 3.6 x 10(6) CD34(+) cells/kg (range 0-60.3) also obta ined following three leukaphereses. The low dose and high dose schedules of G-CSF permitted the collection of 2 x 10(6) CD34-positive cells in 46% and 79% of cases respectively (P=0.01). Twenty-eight patients were transplante d with a peripheral blood stem cell (PBSC) graft and hemopoietic repopulati on was compared with the results of a previous study with autologous bone m arrow. Recovery of granulocytes (>0.5 x 10(9)/l, 17 vs 37 days) and platele ts (>20 x 10(9)/l; 26 vs 96 days) was significantly faster after peripheral stem cell transplantation compared to autologous bone marrow transplantati on. These results demonstrate the feasibility of PBSCT in the majority of c ases with AML and the potential advantage of this approach with respect to hemopoietic recovery.