Comparable Long-Term Survival after Bone Marrow versus Peripheral Blood Progenitor Cell Transplantation from Matched Unrelated Donors in Children with Hematologic Malignancies

Abstract

Despite the increasing use of peripheral blood progenitor cells (PBPC) instead of bone marrow (BM) for allogeneic hematopoietic stem cell transplantation (allo HSCT) from human leukocyte antigen (HLA)-matched unrelated donors in children, the relative benefits and risks of both stem cell sources in the pediatric setting remain largely unknown. Recently, the only larger study comparing the value of the 2 stem cell sources in a young patient group was confined to transplantation from HLA-identical sibling donors in older children and adolescents with acute leukemia. Based on the paucity of data in pediatric HLA-matched unrelated donor transplantation, we analyzed the outcome of 23 BM and 38 PBPC transplantations performed at our center. Neutrophil and platelet engraftment were achieved significantly faster in PBPC compared to BM recipients (18 versus 22 days and 26 versus 33 days; P < .001 and P = .03) whereas the risk for grade II-IV acute graft-versus-host disease (aGVHD) (62% versus 55%; P = .53) and chronic GVHD (cGVHD 65% versus 59%; P = .54) was comparable. As overall survival (OS; PBPC versus BM: 47.5% +/- 8.6% versus 51.8% +/- 10.5%; P = .88) and relapse-free survival (43.3% +/- 8.3% versus 51.8% +/- 10.5%; P = .60) are without detectable difference, PBPC and BM appear both as a valid stem cell source for HLA-matched unrelated donor transplantation in children with hematologic malignancies.

Optimal management of chronic graft‐versus‐host disease in children

“…Paediatric studies looking at this question are small and non-randomized. Meisel et al (2007) compared PBSC to bone marrow in the unrelated setting in paediatrics, and saw the same incidence of chronic GVHD (about 60%) but more extensive chronic GVHD in the PBSC group (50% vs. 26%). A retrospective Center for International Blood and Marrow Transplant Research (CIBMTR) study showed lower survival in paediatric recipients of PBSC compared to marrow, with a higher incidence of cGVHD (Eapen et al, 2004).…”

Impact of CD34+ cell dose in children who receive unrelated PBSCT with in vivo T-cell depletion for hematologic malignancies

“…The day of neutrophil engraftment was defined as the first of 3 days in which the ANC was ⩾ 1000/mm 3 , and the day of platelet engraftment was defined as the first of 3 days in which the platelet count was ⩾ 50 000/mm 3 without platelet transfusions during the previous week. Acute and chronic GVHD were graded according to previously established criteria.…”

“…Risk status at transplant was based on modifications to previously published classification schemes. 3,7 In brief, acute leukemia in first CR, CML in first chronic phase and myelodysplastic syndrome (MDS)-refractory anemia were considered standard risk. Acute leukemia in second CR or greater, or without complete remission, MDS with excess of blasts, juvenile myelomonocytic leukemia and secondary leukemia were considered high risk.…”

“…Consistent with this predilection for PBSC among unrelated donors, several studies have reported on unrelated PBSCT, mainly in the context of comparing important transplantrelated outcomes to BMT. [1][2][3][4][5][6] Studies deriving from a mostly adult HCT population, including a recent randomized trial, conclude that unrelated PBSCT results in similar survival when compared with unrelated BMT, but with a greater incidence of chronic GVHD. 1,2 However, several pediatric studies report that with antibody-based T-cell depletion, such as the use of antithymocyte globulin (ATG) or alemtuzumab (Campath), unrelated PBSCT may result in outcomes that are similar to BMT without an increased risk of GVHD, underscoring the notion that PBSC donation may be as valid an option as BM donation for children in the unrelated transplant setting.…”

“…1,2 However, several pediatric studies report that with antibody-based T-cell depletion, such as the use of antithymocyte globulin (ATG) or alemtuzumab (Campath), unrelated PBSCT may result in outcomes that are similar to BMT without an increased risk of GVHD, underscoring the notion that PBSC donation may be as valid an option as BM donation for children in the unrelated transplant setting. [3][4][5][6] Despite the significant number of reports indicating comparable outcomes for unrelated PBSCT and BMT among pediatric patients, the literature on PBSCT in children outside the framework of comparisons with BMT is limited. For example, risk factors for both acute and chronic GVHD after PBSCT are not clear.…”