T-CELL-DEPLETED GRANULOCYTE-COLONY-STIMULATING FACTOR (G-CSF) MODIFIED ALLOGENEIC BONE-MARROW TRANSPLANTATION FOR HEMATOLOGICAL MALIGNANCY IMPROVES GRAFT CD34(+) CELL CONTENT BUT IS ASSOCIATED WITH DELAYED PANCYTOPENIA

To increase the stem cell content of T cell-depleted bone marrow trans plants (BMT), we treated 12 patients with hematological malignancies w ith BMT from HLA-identical sibling donors given G-CSF 10 mu g/kg/day f or 5 days before marrow harvest, After CD34(+) cell selection, patient s received a median of 1.7 (range, 0.82-3.1) x 10(6) CD34(+) cells/kg and 2.3 (range, 0.25-4.0) x 10(5) CD3(+) cells/kg, All patients had in itial engraftment but four developed pancytopenia between days 55-130 post-BMT, In two patients, this required a second infusion of G-CSF-mo bilized donor peripheral blood progenitor cells, We observed no delaye d pancytopenia in a matched historical group of 24 patients receiving T cell-depleted BMT without prior G-CSF stimulation, Compared to this control group, G-CSF-stimulated marrow recipients showed a significant decline in neutrophil and monocyte counts after 8 weeks, However, out come after BMT was otherwise comparable, with a similar incidence of a cute graft-versus-host disease and transplant-related mortality, Disea se-free survival was 63 vs 67% for controls matched for CD34(+) cell d ose (P = NS). These results indicate that G-CSF stimulation can increa se the CD34(+) cell content of T cell-depleted marrow but carries a ri sk of late graft failure.