Comparing the Efficacy of Tacrolimus and Mycophenolate Mofetil for the Initial Therapy of Active Lupus Nephritis

Inclusion Criteria: 1. Patients who fulfill at least 4 of the ACR criteria for SLE 2. Age \>= 18 years 3. Biopsy proven active lupus glomerulonephritis (ISN/RPS class III/IV/V) 4. Serum creatinine \< 200 umol/L at the time of randomization Exclusion Criteria: 1. Patients who refuse to be randomized for treatment 2. Patients who prefer treatment with conventional agents such as oral or intravenous CYC for various reasons 3. Serum creatinine \>= 200 umol/L at the time of randomization 4. Patients without renal biopsy or those who have lupus nephritis ISN/RPS class I,II,VI 5. Patients who are pregnant or plan for pregnancy within 12 months after randomization