Inclusion Criteria:

- Recipient age ≥18 and ≤ 75 ans.

- Patients having received a first or second renal transplant from a cadaveric or
living related donor between 12 and 24 months prior the inclusion.

- Peak panel reactive antibody (PRA) < 30 %

- Patients with a stable renal function during the 3 months prior to inclusion
(variation of serum creatinine lower than 20 %)

- Creatinine clearance ≥ 40 ml/mn/1.73 m26.

- Patients receiving as a stable immunosuppressive treatment associating: Mycophenolate
mofétil (MPA AUC > 30 mg.h/L) and Tacrolimus with a trough level > 4 ng/ml, with or
without corticoids

Exclusion Criteria:

- Multi-organ recipients

- Patients receiving cyclosporine

- Pregnancy

- Recipients of ABO incompatible graft

- Use of other immunosuppressive drugs.

- Historical peak reactive antibody ≥ 30 %

- Past medical history of humoral rejection, 2 episodes of acute cellular rejection

- Past medical history of sub-clinical rejection on routine allograft biopsy

- Calculated creatinine clearance < 40 ml/mn/1.73 m2

- 24h proteinuria > 1 g/24H

- Patients with severe diarrhea

- HTLV1 or HIV positivity

- Known hypersensitivity to tacrolimus, mycophénolate mofétil, or sirolimus.

- Total white blood cells < 2500/mm3 or hemoglobine < 9 g/dl