11. Patients with a history of coagulopathy or medical condition that would require long-term anticoagulation therapy after transplantation, unless the condition would permit a two week interruption in therapy before and after allograft biopsy. (Treatment with low dose aspirin is allowed.) 12. Women of childbearing potential who are either pregnant, lactating, planning to become pregnant during this trial, or with a positive serum or urine pregnancy test. Women of childbearing potential must be willing to agree to contraceptive practices.