Long-Term Follow-Up after Allogeneic Granulocyte Colony-Stimulating Factor-Primed Bone Marrow Transplantation

Granulocyte colony-stimulating factor (G-CSF) priming increases the number of progenitor cells in harvested bone marrow (BM) and has been used for allogeneic transplantation. Primed bone marrow (pBM) seems to offer faster engraftment than steady-state BM, but the stability of such engraftment has been questioned. The incidence of graft-versus-host disease (GVHD) and disease relapse after pBM, compared with such incidence after BM or peripheral blood progenitor allotransplantation, has not been established. We studied the long-term outcome (median follow-up, 24 months) of sibling matched allografting with G-CSF pBM. Seventeen patients received pBM from matched sibling donors primed with G-CSF 10 μg/kg per day for 2 days before BM harvest. Conditioning consisted of total body irradiation and cyclophosphamide (CY); busulfan and CY; or total lymphoid irradiation, CY, and antithymocyte globulin. All infused grafts contained ≥3.5 to 4 × 10⁸ mononuclear cells per kilogram. Ten of 17 patients received methotrexate as part of their GVHD prophylaxis. International Bone Marrow Transplant Registry definitions for engraftment were used. Control subjects consisted of 112 consecutive patients who received allogeneic transplantation at our institution with steady-state BM; control subjects for length of hospitalization consisted of the subset of patients who underwent transplantation during 1996. Neutrophil engraftment occurred a median of 7 days earlier in primed bone marrow transplantation (pBMT) patients when compared with steady-state BMT patients; this shortened hospitalization by a median of 11 days. The peritransplant mortality rate was 18% in pBMT patients and 25% in BMT patients (not significant). The rate of GVHD of grade >II and the rate of relapse were almost identical in pBMT and BMT patients (GVHD: 18% and 19%, respectively; relapse: 14% and 13%, respectively). There were 4 transplant-related deaths within the first 100 days; 1 patient died of disease relapse on day 470. Twelve patients remained alive on days 430 through 1522 after BMT. Results showed that pBM allografts resulted in more rapid engraftment and shorter hospitalization. All patients maintained stable donor engraftment. In this cohort of patients, G-CSF pBMT resulted in rates of GVHD, disease relapse, and peritransplant mortality that were similar to those produced by conventional BMT.