Granulocyte colony-stimulating factor given to donors before apheresis does not prevent aplasia in patients treated with donor leukocyte infusion forrecurrent chronic myeloid leukemia after bone marrow transplantation

We conducted 2 sequential studies of donor leukocyte infusion (DLI) in 26 p atients with chronic myeloid leukemia in hematologic relapse after unmodifi ed allogeneic bone marrow transplantation. In the first study, cells for DL I were collected from 13 donors who were not treated with granulocyte colon y-stimulating factor (G-CSF) (group 1). In the second study, cells were col lected from 13 donors who received G-CSF before apheresis (group 2) in an a ttempt to avoid aplasia after DLI. Patients in group 2 received 550-fold mo re CD34(+) cells than those in group 1. We found no significant difference in the incidence (31% versus 22%), onset time (41 vs. 48 days), or duration (15 vs. 14 days) of cytopenia after DLI in the 2 groups. G-CSF given to do nors before collection of cells did not prevent aplasia. These findings sup port the hypothesis that the pathogenesis of aplasia after DLI is not restr icted to the destruction of recipient hematopoietic cells but also involves failure of donor hematopoiesis by undefined mechanisms.