We evaluate the usefulness of a newly-developed T cell-based assay prior to undergoing immunosuppression in renal transplant recipients. Among all renal transplant recipients, patients with negative tuberculin skin test and no other indications for latent tuberculosis infection will be enrolled in this study. We will exam T-SPOT.TB test in these patients, and observe the developement of tuberculosis within 1 to 2 years after the transplantation. The results of T-SPOT.TB will be blinded to the investigators.