A Study to Evaluate the Efficacy and Safety of Tacrolimus With Steroid in Korean Lupus Nephritis Patients

Inclusion Criteria: * Patients who satisfy more than 4 criteria for diagnosis of systemic lupus erythematosus (ARA criteria, 1982) * Patients who fall under WHO class III-IV lupus nephritis on renal biopsy * Patients with refractory lupus nephritis * Proteinuria ≥ 0.5 g/day * Patients who took steroid ≥ 20 mg/day over one month prior to the study * Patients who failed a first-line therapy (non-responders to steroid monotherapy) Exclusion Criteria: * Patients who are allergic or resistant to macrolide antibiotics or tacrolimus * Patients who received tacrolimus in the past (excluding drugs for external use) * Patients who used other immunosuppressants within 4 weeks before initiation of the study * Patients who have been receiving systematic chemotherapy since before enrollment (local chemotherapy is allowed.) * Patients with malignant tumor which developed within the recent 5 years or history of malignant tumor * Patients who have severe diarrhea, vomiting, active peptic ulcer or gastrointestinal disorders which may influence absorption of tacrolimus * Patients with S-Cr ≥ 200 µ㏖/L or ≥ 2.3 mg/dL * Patients with liver function levels of more than twice the upper limit of normal or acute active hepatitis