Improved Methods of Cell Selection for Bone Marrow Transplant Alternatives

Bone marrow transplants (BMT) are one form of treatment for disorders of the blood, including leukemia. However, because the procedure is often associated with potentially life-threatening reactions, it is usually reserved for patients with serious illnesses under the age of 60 years old. One serious reaction complicating bone marrow transplants is referred to as graft-versus-host disease (GVHD). GVHD is a potentially fatal incompatibility reaction. The reaction is caused by antigens found on the cells of the patient that are not present on the cells of the donor. The antigens are recognized by transplanted white blood cells (lymphocytes). These lymphocytes begin attacking the recipient s cells and tissues and may lead to death. In order to avoid GVHD, researchers have developed a technique using peripheral blood instead of bone marrow that allows transplantation of stem cells and removal of lymphocytes. Stem cells are the cells responsible for returning blood cell production to normal. Lymphocytes are the white blood cells that can cause GVHD. The technique requires two steps. In the first step blood cells are collected from donors who have received doses of a growth factor. The growth factor (granulocyte colony stimulating factor) is designed to increase the production of donor stem cells. In the second step white blood cell lymphocytes are removed from the collected blood, leaving only the stem cells. The main goal of this study is to develop and improve the method of processing cells that are collected after stimulation with growth factor (G-CSF), by removing the white blood cell lymphocytes which can cause graft-versus-host disease (GVHD) while keeping the stem cells necessary for healthy blood cell building. In addition, researchers are interested in studying whether giving G-CSF has an effect on lymphocyte function, which may influence the immune reactions occurring in bone marrow transplantation.