Mesenchymal Stem Cell (MSC) have been shown to have immunosuppressive and repairing properties. the investigators will infuse expanded MSC into patients who develop Chronic Allograft Nephropathy. The purpose of this study is to find out MSC is more effective in preventing organ rejection and maintaining kidney function.

Kidney transplantation is a common procedure in hospitals, but organ rejection and chronic nephrotoxicity are potential problems for the patient. Approximately ninety percent of the protocol biopsies of renal allografts, performed at 18 months post transplantation, show histological lesions of chronic calcineurin nephrotoxicity. Mesenchymal Stem Cell (MSC) has been shown to have immunosuppressive and repairing properties. Some patient in this study will also receive two infusions of expanded MSC. This study will evaluate the safety and effectiveness of MSC infusions in patients .

This study will last 2 years. Participants will be randomly assigned to receive either the full immunosuppressive therapy and MSC infusions (Group 1) or immunosuppressive therapy alone (Group 2). Patients will undergo MSC infusions at the start of the study on Day 0. One year post- infusions, patients will be evaluated. At Months 12 participants will undergo kidney biopsies. Blood collection will occur at regular intervals, Serum creatinine and the estimated creatinine clearance will be monthly recorded. The transplanted kidney function will be evaluated.

Inclusion Criteria:

• Recipients of a renal allograft, Male and female patients age 18 to 60 years of age.
• Ability to provide written informed consent.
• The serum creatinine form 176umol/L(2mg/ml) to 440umol/L(5mg/ml)
• Renal biopsy Criteria: chronic allograft nephropathy (Banff I-II).
• Immunosuppressant:CNI and MMF and Sirolimus
• Written informed consent, compliant with local regulations.

Exclusion Criteria:

• Recipients with leucopenia (WBC < 3000/mm³), thrombocytopenia (Thr < 100.000/mm³),or hyperlipidemia (Tot Chol > 300 mg/dl or Triglycerides > 300 mg/dl).
• Recipients of multiple organs.
• Pregnant women.
• Previous history of malignancy
• Active infection including hepatitis B, hepatitis C, HIV, or TB as determined by a positive skin test or clinical presentation, or under treatment for suspected TB.
• Evidence of cardiovascular disease, existing congestive cardiac failure on physical exam and/or acute coronary syndrome in past 6 months.
• Inadequate compliance to treatment.