Bone Marrow Transplant Rejection clinical trials

Stem Cell Transplantation and T-Cell Add-Back to Treat Bone Marrow Malignancies

This study will evaluate the safety and effectiveness of stem cell transplantation in which the donor's T cells (a type of lymphocyte, or white blood cell) are removed and then added back. Certain patients with bone marrow malignancies undergo transplantation of donated stem cells to generate new and normally functioning bone marrow. However, T-cells from the donor may see the patient's cells as foreign and mount an immune response to reject them, causing what is called "graft-versus-host-disease" (GVHD). Therefore, in this protocol, T-cells are removed from the donor cells to prevent this complication. However, because T-cells are important in fighting viral infections as well as any remaining malignant cells (called graft-versus-leukemia effect), the donor T-cells are given to the patient (added back) at a later time after the transplant when they can provide needed immunity with less risk of causing GVHD. Patients between 10 and 55 years of age with acute or chronic leukemia, myelodysplastic syndrome, or myeloproliferative syndrome may be eligible for this study. Prospective participants and their donors are screened with a medical history and physical examination, blood tests (including a test to match for genetic compatibility), breathing tests, chest and sinus x-rays, and tests of heart function. They also undergo a bone marrow biopsy and aspiration. For this procedure, done under local anesthetic, about a tablespoon of bone marrow is withdrawn through a needle inserted into the hipbone. They undergo apheresis to collect lymphocytes for research studies. This procedure involves collecting blood through a needle in the arm, similar to donating a unit of blood. The lymphocytes are then separated and removed by a cell separator machine, and the rest of the blood is returned through a needle in the other arm. Before treatment begins, patients have a central intravenous line (flexible plastic tube) placed in a vein in the chest. This line remains in place during the stem cell transplant and recovery period for drawing and transfusing blood, giving medications, and infusing the donated cells. Preparation for the transfusion includes high-dose radiation and chemotherapy. Patients undergo total body irradiation in 8 doses given in two 30-minute sessions a day for 4 days. Eight days before the transplant, they begin taking fludarabine, and 3 days before the procedure they start cyclophosphamide.