Hematopoietic Cell Transplantation
Hematopoietic cell transplantation is a procedure by which hematopoietic stem and progenitor cells are infused intravenously to restore hematopoiesis and immune function following a chemotherapy conditioning regimen, with or without radiation therapy, that ablates the endogenous hematopoietic and immune system. Stem/progenitor cells can be collected from a variety of sources, including bone marrow, peripheral blood, or umbilical cord blood. The three types of hematopoietic cell transplantation are syngeneic (i.e., cells from an identical twin), allogeneic (i.e., cells from a nonidentical donor), and autologous (i.e., reinfusion of one’s own cells). Because of better tissue typing, less intensive preparatory regimens, modern supportive measures, and expanded options for identifying qualified donors, the outcomes of hematopoietic cell transplantation have steadily improved. Hematopoietic cell transplantation is now used to treat blood cancers and other malignancies, enzyme deficiencies, hemoglobinopathies, and autoimmune disorders. Complications associated with all forms hematopoietic cell transplantation include direct organ toxicities from the conditioning regimen as well as prolonged cytopenias that can result in infections and bleeding. Graft-versus-host disease (i.e., the donor rejecting the recipient) is a complication unique to allogeneic hematopoietic cell transplantation. Recurrence of malignancy remains the primary cause of treatment failure after both autologous and allogeneic hematopoietic cell transplantation.
