Concentration-controlled Therapy of Mycophenolate Mofetil (MMF) in Proliferative Lupus Nephritis

Inclusion Criteria: * Age 16-60 years. * Ability and willingness to provide written informed consent (or to obtain consent from parent guardian where applicable) and to comply with the schedule of protocol requirements * Diagnosis of SLE according to ACR criteria. At least 4 criteria must have been present for the diagnosis of SLE. The 4 criteria do not have to be present at the time of screening * Active lupus nephritis defined as follows: Biopsy proven (within 16 weeks prior to screening) ISN Class III or IV (A or A/C) not include III(C) IV(C) and VI (\>90% chronic irreversible scarring) Exclusion Criteria: Relates to SLE * Severe renal impairment as defined by calculated creatinine clearance or MDRD-GFR \< 30 ml/min(except creatinine clearance or MDRD-GFR \> 50 ml/min in the 12 weeks prior to screening) * History of serious disease or complication in any organ system that not appropriate to treatment immunosuppressive drug groups. Related to Treatment * Previous of any Mycophenolate groups in the 3 months prior to screening. * Treatment with more than 2 g Cyclophosphamide in the last 6 months period prior to screening. * Receipt of more than 3 g IV pulse methylprednisolone within the last 3 months prior to screening. * Receipt of prednisolone dose \> 30 mg/day for longer than 30 days within last 3 months prior to screening. Related to General Health * Pregnancy or breast feeding mothers. * Evidence of significant uncontrolled concomitant disease in any organ system not related to SLE. * History of cancer, including solid tumors, hematological malignancies and carcinoma. * History of serious recurrent or chronic infection. * Evidence of current abuse of drugs or alcohol. Related to Laboratory Findings * Neutrophile \< 1,500/mm3, Hb \< 7g/L, Platelet \< 50,000/mm3 (except active SLE) * Positive HBsAg or anti-HCV or anti-HIV.