G-CSF PRIMED PERIPHERAL-BLOOD PROGENITOR CELLS IN AUTOLOGOUS BONE-MARROW TRANSPLANTATION - PARAMETERS AFFECTING BONE-MARROW ENGRAFTMENT

G-CSF and GM-CSF enhance the rate of neutrophil engraftment in autolog ous bone marrow transplantation (ABMT) without significantly affecting platelet engraftment. Peripheral blood progenitor cells (PBPC) may en hance rates of engraftment of both neutrophils and platelets. We treat ed 49 patients undergoing ABMT with a course of G-CSF to obtain PBPC a nd infused these cells post-transplant with G-CSF in an attempt to det ermine factors which might correlate with enhanced BM engraftment. For ty-nine patients with Hodgkin's disease, non-Hodgkin's lymphoma or bre ast cancer undergoing unpurged ABMT were studied. G-CSF priming consis ted of an outpatient 8 day course of 5 mu g/kg/day followed by three l eukaphereses (on day 5, 7 and 8) to collect PBPC. Patients then receiv ed a chemotherapeutic BMT preparative regimen followed by an infusion of PBPC, autologous BM and the reinstitution of G-CSF (16 mu g/kg/day) . BM engraftment was rapid. The median time to achieve 0.5 x 10(9)/1 n eutrophils was 10 days compared with a historical BMT control patient population receiving the same preparative regimens of 19 days (p = 0.0 01). Time to achieve a platelet count of 20 X 10(9)/1 was 16 days comp ared with a historical control of 22 days (p = 0.001). Neutrophil engr aftment occurred in all patients by day +14. Marrow engraftment correl ated with the total number of CD34(+) cells infused as well as the tot al number of mononuclear cells infused but not the total number of CD3 4(+)/CD33(-) cells infused. The amount of total blood volume pheresed significantly correlated with yield of total mononuclear cells. Prior exposure to radiation therapy negatively correlated with progenitor ce ll yield. The rapid marrow engraftment resulted in an average total ho spital stay of 29 days compared with a historical control of 39 days ( p = 0.01). To date, relapse rates of the two study groups have been si milar. These data suggest that treatment with G-CSF can result in exce llent mobilization of PBPC. Furthermore, the addition of G-CSF primed PBPC plus G-CSF with autologous marrow in ABMT enhances both platelet and neutrophil engraftment rates which ultimately leads to a decreased total hospital stay.