Background and objective: Transplantation of mobilized allogeneic peripheral blood stem cells (PBSC) has recently been reported by several groups. However, few patients receiving an allograft in the early stage of their disease have been described so far.
Design and methods: Fifteen patients with early stage hematologic malignancies were transplanted with cryopreserved allogeneic PBSC from HLA-identical siblings. PBSC were collected after priming with 10 micrograms/kg/day of glycosylated granulocyte colony-stimulating factor (G-CSF, lenograstim). Outcomes were compared to a historical control group of 15 patients who received conventional bone marrow transplantation (BMT) from HLA-identical sibling donors. The two groups were matched for diagnosis, stage of disease, age, preparative regimen, graft-versus host (GVHD) prophylaxis, patients' and donors' gender and cytomegalovirus (CMV) serology. Diagnoses in both groups were: chronic myelogenous leukemia (CML) in first chronic phase (= 5), acute leukemia in first complete remission (CR) (= 5), non-Hodgkin's lymphoma in CR (= 1) and multiple myeloma (MM) with sensitive disease (= 4). All patients were given cyclosporin-A (CsA) and methotrexate (MTX) for GVHD prophylaxis. Preparative regimens varied according to diagnosis and included either busulfan/cyclophosphamide combination (BU/Cy) or total body irradiation/cyclophosphamide +/- melphalan (TBI/Cy +/- Mel).
Results: The patients in the PBSC group showed a more rapid hematopoietic reconstitution with a significant difference in the median times to 1 x 10(9) neutrophils/L (19 days vs. 26 days; p = 0.03) and to platelet transfusion independence (18 days versus 22 days; p = 0.02). This finding was associated with a significantly shorter hospitalization (28 days versus 33 days after transplantation; p = 0.01). In the PBSC series, grade II-IV acute GVHD occurred in 3 patients (20%) and grade III-IV in 1 patient (7%). In the BMT control group, grade II-IV aGVHD was reported in 2 cases (13%; p = NS) and 1 case had grade III-IV GVHD. Chronic GVHD developed in 7 patients (47%) (limited = 6; extensive = 1) undergoing PBSC transplantation and 5 patients (33%) (limited = 4; extensive = 1) in the BMT series (p = NS). No difference was found in the incidence of grade II-IV (according to the World Health Organization) mucositis, whereas PBSC recipients did have a significantly lower incidence of additional severe (grade III-IV) organ toxicity. After a median follow-up of 300 days (range 180-630), all PBSC patients are still alive with a median Karnofsky score of 100% (range 80%-100%). Thirteen patients are in CR and 2 myeloma patient are in good partial remission (PR). Also, in the BMT group the peritransplant mortality was absent; two MM patients died due to progressive disease at day +796 and +1,023, respectively; one leukemic patient died of chronic GVHD 407 days after transplantation and one additional leukemic individual relapsed 1,140 days after BMT.
Interpretation and conclusions: This retrospective comparison suggests that allogeneic PBSC transplantation performed in the early stage of the disease is safe and may be associated with a more rapid hematopoietic reconstitution than BMT, as well as lower transplant-related toxicity and earlier hospital discharge with apparently no increased risk of acute and chronic GVHD.