ABSTRACT

I. INTRODUCTION In the late 1960s, Epstein et al. and Storb et al. reported on a canine model set up to investigate the possibility of transplanting allogeneic blood stem cells (1,2). These series of experiments, later followed by transplant studies in nonhuman primates gave the first evidence that hematopoietic stem cells circulate in the peripheral blood and can engraft in allogeneic recipients (3). A unique and successful attempt to transplant T-cell-depleted blood stem cells from a normal donor to an human leukocyte antigen (HLA)–identical recipient with acute lymphoblastic leukemia was published in 1989 (4).