A Study Looking at Kidney Function in Kidney Transplant Recipients Who Are Taking Anti-rejection Medication Including Tacrolimus and With or Without Sirolimus.

Inclusion Criteria: * End stage kidney disease and a suitable candidate for primary renal transplantation or re-transplantation (unless the graft was lost from rejection within 6 months) * Receiving a kidney transplant from a deceased or living (non Human Leukocyte Antigen \[HLA\] identical) donor with compatible ABO blood type * Female subject of childbearing potential has a negative serum or urine pregnancy test at enrollment * Female and male subjects agree to maintain highly effective birth control during the study and for 90 days after discontinuation of dosing with study drugs. A highly effective method of birth control is defined as those which result in a low failure rate (CPMP/ ICH/ 286/ 95 modified) of less than 1% per year when used consistently and correctly such as implants, injectables, combined oral contraceptives, some Intrauterine Devises (IUDs), sexual abstinence or vasectomized partner Exclusion Criteria: * Receiving or having previously received an organ transplant other than a kidney * Cold ischemia time of the donor kidney \> 30 hours * Panel Reactive Antibody (PRA) \>20% * Receiving a graft from a non-heart-beating donor other than of Maastricht category 3 (withdrawal of support awaiting cardiac arrest) * Significant liver disease, defined as having continuously elevated SGPT/ ALT and/ or SGOT/ AST and/ or total bilirubin levels ≥ 2 times the upper value of the normal range of the investigational site or is receiving a graft from a hepatitis C or B p…