Background:
There has been changed in estimation of the stem cell content of the graft for several decades. However, there is not always correlating the transplanted cell dose with hematologic recovery, and there are few reports in human leukocyte antigen (HLA)-matched sibling allogeneic bone marrow transplantation (AlloBMT) in Korea. The purpose of this study is to report the influence of number of transplanted cell dose on hematologic recovery and the clinical outcomes in HLA-matched sibling AlloBMT.
Methods: Between June 1999 and March 2004, 31 AlloBMT from HLA-matched sibling donor was done in patients with hematologic malignancy. All patients were conditioned with busulfan and cyclophosphamide. Short course methotrexate and cyclosporine regimen was used for prophylaxis of graft-versus-host disease. We analyzed hematologic recovery time and clinical outcomes according to transplanted cell dose.
Results:
There were 16 male and 15 female patients, with a median age of 34 years (range, 16∼48). Underlying diseases were 17 acute myeloid leukemia, 4 acute lymphoblastic leukemia, 3 myelodysplastic syndrome (high-risk), and 7 chronic myelogenous leukemia. The median number of total nucleated cell (TNC), mononuclear cell (MNC) and CD34+ cell infused was 3.95×108/kg (range, 1.67∼7.30×108/kg), 0.65×108kg (range, 0.11∼2.50×108kg), and 2.32×106kg (range, 0.35∼7.45×106kg), respectively. The median days of neutrophil and platelet engraftment (ANC＞500/ՌL and platelet＞20,000/L without transfusion) were 15 (range, 10∼19), 16 (range, 7∼37), respectively. Relationship between the rate of neutrophil engraftment and the number of infused TNC was only statistically significant (P=0.038, R20.328). This study showed survival benefit with the increment of CD34+ cell dose without significance statistically (P=0.082).
Conclusion: Although the dose of the number of transplanted MNC and CD34+ cells had no influence on granulocyte or platelet recovery, the number of TNC had only a beneficial effect on neutrophil recovery. The transplanted dose of CD34+ cells, rather than those of TNC and MNC may be related with better survival.

Keywords: HLA-matched sibling AlloBMT, Cell dose, Hematologic recovery, Clinical outcome