Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content ++ SOURCES OF HEMATOPOIETIC STEM CELLS ++ Marrow ++ Marrow for hematopoietic cell transplantation (HCT) is typically aspirated by repeated placement of large-bore needles into the posterior iliac crest, generally 50 to 100 aspirations simultaneously on both sides, while under regional or general anesthesia. The lowest cell dose to ensure stable long-term engraftment has not been defined with certainty. Typical collections contain more than 2 × 108 total nucleated marrow cells/kg recipient body weight. Current guidelines indicate that a volume of up to 20 mL/kg donor body weight is considered safe. The risk of serious complications is about 2%. ++ Peripheral Blood Progenitor Cells ++ The most common method to harvest autologous peripheral blood progenitor cells (PBPCs) is by using granulocyte colony-stimulating factor (G-CSF) with or without chemotherapy. In contrast, PBPCs for allogeneic HCT are typically mobilized with G-CSF alone. This procedure is safe and in a review of nearly 7000 healthy unrelated donors, serious side effects were uncommon (< 1%). Splenic rupture is extremely rare. The measurement of the absolute number of CD34+ cells/kg recipient body weight collected is a reliable and practical method for determining the adequacy of the PBPC product. A minimum of 2 × 106/kg CD34+ cells is usually recommended, although at this dose, 10% to 20% of autologous collections lead to suboptimal (slow, or more rarely, no) engraftment. Platelet recovery is most sensitive to borderline collection numbers. Randomized clinical trials have indicated that engraftment is more rapid with PBPCs than with marrow-derived stem cells. Although the number of T cells in peripheral blood stem cell (PBSC) graft is 10-fold greater than in marrow, the incidence of acute graft-versus-host disease (GVHD) does not appear higher, probably because G-CSF influences the proportion of immune tolerizing Treg cells in the apheresis product. However, the risk of chronic GVHD has been found to be about 10% higher in PBSC at most major transplant centers. The use of G-CSF to mobilize stem cells in patients with sickle cell anemia is contraindicated, because an acute increase in neutrophil counts can precipitate a catastrophic sickle cell occlusive crisis. ++ Umbilical Cord Blood ++ Umbilical cord blood (UCB) collected from the umbilical vessels in the placenta at the time of delivery is a rich source of hematopoietic stem cells (HSCs). Because these cells are immunologically relatively naive, recipients may have satisfactory outcomes, even when crossing major histocompatibility barriers. The minimum acceptable cell dose for single-unit UCB transplantation is greater than or equal to 2.5 × 107 total nucleated cells or greater than or equal to 2 × 105 CD34+ cells/kg recipient weight. For adults, this usually requires the use of two suitably matched cord bloods, providing a higher total CD34+ dose. ++ DEGREE OF MATCHING ++ Human Leukocyte Antigen (HLA)-Matched Related Donor ++ HLA-matched sibling donors were the most common source ... GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. What is MyAccess? Create a FREE MyAccess profile to: Use this site remotely Bookmark your favorite content Track your self-assessment progress and more!