Efficacy and Safety of Sirolimus Plus CNI Compared With MMF Plus CNI in ABO-i Kidney Transplant Recipients.

Inclusion Criteria: \[Time of Screening\] 1. Patients who plan to be transplanted ABO incompatible living donor kidney or not past 35 days after kidney transplantation 2. More than the age of 19 years old 3. Agreement with written informed consent \[Time of Randomization\] 1. Patients who have transplanted Kidney within 4 weeks(25 days to 35 days) 2. Patients who take CNI plus MMF after kidney transplantation Exclusion Criteria: \[Time of Screening\] 1. Patients who have transplanted non-kidney organs or have plan to be transplanted non-kidney organs 2. PRA \> 50% before desenitization or positive results of DSA 3. Receive a kidney from a related donor who showed HLA identical 4. Positive in serology test(HIV, HBsAg, HCV) in recipients and/or donor 5. Allergic/hypersensitivity reaction in the history of Investigational drugs or additives 6. Women who are pregnant or breast feeding or not agree to the proper use of contraception during the trial 7. Patient has conversation impairment because of mental illness within 6months 8. Participated in other trial within 4 weeks 9. In investigator's judgement \[Time of Randomization\] 1. Patients with acute rejection who have been clinically treated after kidney transplantation 2. At the time of Randomization * Treatment with active liver disease or Liver function test(T-bilirubin, AST, ALT)is over 3 times than upper normal limit * WBC\< 2,500/mm\^3, or platelet \< 75,000/mm\^3, or ANC \< 1,300/mm\^3 3. Patients who had plasmapheresis within 1 week 4. Patents who had a record of taking mTOR inhibitor before 5. In investigator's judgement