Mobilization and Handling of Stem Cells for Transplant From Healthy Volunteers With Sickle Cell Trait

This study will examine the effects of granulocyte colony-stimulating factor (G-CSF) on bone marrow stem cells in healthy volunteers with sickle cell trait and determine if cells collected for transplantation from donors with sickle cell trait require special handling. Stem cells, which the bone marrow produces, are responsible for making all the different kinds of blood cells. They are the cells used in bone marrow, or stem cell, transplantation. The drug G-CSF, which is a naturally occurring hormone, causes stem cells to mobilize-that is, to be released from the bone marrow and enter the blood stream. This drug is given to stem cell donors to increase the amount of cells that can be collected. Stem cell donors for patients with sickle cell disease are often healthy siblings of the patient who have a matching bone marrow type. Some siblings carry the sickle cell trait, however, and, even though they do not have sickle cell disease and their blood and bone marrow are normal, it is not known how their cells will react to G-CSF stimulation. Nor is it known if their stem cells require special methods of removal, processing or storing. Healthy volunteers 18 years or older with sickle cell trait who have no history of sickle cell disease and no known medical problems may be eligible for this study. Participants will have a medical history and physical examination, including blood tests and urinalysis. They will receive injections of G-CSF under the skin once a day for 5 days. On the fifth day, stem cells will be collected through leukapheresis. In this procedure, whole blood is drawn from an arm vein, similar to donating whole blood. The blood then circulates through a cell separator machine, the stem cells are removed, and the rest of the blood is transfused back to the donor through a vein in the other arm. The information gained from this study will be used to ensure the safety of stem cell donors with sickle cell trait and to better prepare stem cells for transpla