Blood stem cells compared with bone marrow as a source of hematopoietic cells for allogeneic transplantation. IBMTR Histocompatibility and Stem Cell Sources Working Committee and the European Group for Blood and Marrow Transplantation (EBMT).

Peripheral blood cells are increasingly used in place of bone marrow as a source of hematopoietic stem cells for allogeneic transplantation. The relative efficacy of these 2 approaches is unknown. This retrospective multivariate analysis compared results of 288 HLA-identical sibling blood stem cell transplantations with results of 536 HLA-identical sibling bone marrow transplantations. No transplants were T-cell depleted. Median follow-up was 12 months, and analyses focused on 1-year outcomes. Recipients of blood stem cell transplants had more rapid recovery of neutrophils to at least 0.5 x 10(9)/L (median time to recovery, 14 days, compared with 19 days for marrow transplants; P <.001) and of platelets to at least 20 x 10(9)/L (median time, 18 days, compared with 25 days for marrow transplants; P <.001). There was no significant difference in the incidence of grades II to IV acute graft versus host disease (GVHD). The incidence of chronic GVHD was significantly higher after blood stem cell transplantation (1-year probability [95% confidence interval], 65% [56%-72%] compared with 53% [47%-59%]; P =.02) Relapse incidence in the 2 transplant groups did not differ significantly. Treatment-related mortality rates were lower and leukemia-free survival rates were higher with blood stem cell transplants in patients with advanced leukemia (acute leukemia in second remission or chronic myelogenous leukemia in accelerated phase) but not in early leukemia (acute leukemia in first remission or chronic myelogenous leukemia in chronic phase). The median time from transplantation to hospital discharge was 23 days after blood stem cell transplantation and 28 days after bone marrow transplantation (P =.003). Further study with longer follow-up is necessary to definitively establish the role of blood stem cells for allogeneic transplantation, especially in patients with good-risk disease. (Blood. 2000;95:3702-3709)