Combination Drug Therapy Followed by Single Drug Steroid Free Therapy to Prevent Organ Rejection in Kidney Transplantation

This study will test the safety and effectiveness of a combination of three drugs followed by long-term treatment with just one drug in preventing organ rejection in kidney transplant patients. Current anti-rejection medicines are not completely effective in preventing rejection. This trial will test how well Thymoglobulin, Tacrolimus, and Sirolimus work together post-transplant and if the treatment can be reduced over time to control rejection with either Tacrolimus or Sirolimus alone. Candidates for kidney transplantation at the National Institutes of Health Clinical Center may participate in this 5-year study. Patients will be screened for eligibility with a medical history, physical examination, and blood tests. Participants will undergo the following tests and procedures: * Central line placement: A large intravenous catheter (plastic tube, or IV line) is placed in a vein in the chest or neck under local anesthesia before the transplant surgery. The line remains in place for some time during the hospitalization to administer Thymoglobulin, antibiotics, and blood, if needed. The line is also used to collect blood samples. * Leukapheresis: This procedure for collecting white blood cells is done before the transplant. The cells are studied to evaluate the patient's immune system. Whole blood is withdrawn through a catheter in an arm vein or through the central line and directed into a machine that separates the blood components by spinning. The white cells are removed and the red cells and plasma are returned to the body. * Kidney transplant: Patients undergo kidney transplant surgery under general anesthesia. * Immunosuppressive therapy: Patients receive thymoglobulin by vein for 4 days starting 1 day before the transplant. They also take Tylenol, Benadryl and a steroid (methylprednisolone) to help reduce the side effects of the Thymoglobulin. After the transplant, patients receive Tacrolimus and Sirolimus by mouth once a day for 6 months and then either Tacrolimus or Sirolimus alone indefinitely. In addition, they take medicines to help prevent viral and fungal infections for 6 months because the immunosuppressive therapy leaves them vulnerable to infection. * Follow-up visits: After hospital discharge, patients return to the Clinical Center twice a week for 4 weeks, then every 6 months for 1 year, and then yearly for another 4 years. At each visit, the patient's vital signs are checked and blood and urine samples are collected. Periodically, patients are also questioned about how they feel and how the transplant has affected their quality of life. Kidney biopsies (removal of a small amount of kidney tissue through a thin needle) are done when the patient begins single-drug immunosuppression (generally 6 months after transplantation) and 1 year after that. The biopsied tissue is examined to evaluate how well the kidney is responding to the treatment and to determine how to proceed with therapy. * Routine laboratory tests: Routine tests, coordinated by the patient's local physician, are done 2 to 3 times a week for the first 2 to 3 months after transplantation, then weekly for several more months, and at least monthly for life.