Abstract

The first successful allogeneic bone marrow transplants were performed in children with severe combined immune deficiency (SCID). Bone marrow transplants for patients with SCID have been in the forefront of clinical bone marrow transplantation including the first successful use of T lymphocyte-depleted haploidentical bone marrow and matched unrelated donors. Successful bone marrow transplantation for most forms of SCID requires only the engraftment of donor lymphoid stem cells; donor hematopoietic stem cell engraftment is usually not required. The Wiskott-Aldrich syndrome was the first genetic disease involving the hematopoietic stem cell to be completely corrected by allogeneic bone marrow transplantation. The successful transplantation of Wiskott-Aldrich syndrome patients demonstrated that agents with adequate anti-lymphoid and hematopoietic stem cell activity were necessary in order to achieve complete donor lymphoid and hematopoietic stem cell engraftment. Initially, total body irradiation and now busulfan are used to ablate recipient hematopoietic stem cells, while cyclophosphamide is used to ablate recipient lymphoid stem cells. No single agent/drug is capable of eliminating both stem cell populations. Histocompatible bone marrow transplantation has a role in the treatment of patients with immune deficiency due to primary defects of the hematopoietic stem cell. The recent introduction of cytokines (gamma-interferon and granulocyte colony stimulating factor) may reduce the need for bone marrow transplantation for myeloid immune deficiency states. Initial attempts to treat patients with the acquired immune deficiency syndrome by bone marrow transplantation were limited by the lack of effective concomitant anti-viral therapy. Bone marrow transplantation for immune deficiency states continues to be in the forefront of human bone marrow transplantation.