The Efficacy and Tolerance of Tacrolimus Sustained-release Capsules on Refractory Nephrotic Syndrome (RNS)

Inclusion Criteria: * Subjects of either sex, 14-60 years of age * Diagnosis of Nephrotic syndrome with hypoalbuminemia (\< 3.0g/dl) and heavy proteinuria (\> 3.5g/24hr) and exclude secondary Nephrotic syndrome * Refractory Nephrotic Syndrome 1. Steroid resistant: failure to respond (either complete or partial remission) after a course of 8 weeks of 1.0 mg/kg/d prednisone or equal dose of steroid therapy 2. Steroid dependent: recurrence of nephrotic proteinuria during tapering of prednisone at a dose \> 10 mg/day or within the first 2 weeks after withdrawal of prednisone 3. Frequently recurrence: initial remission with steroid induction therapy, but relapsed 2 or more in 6 months or 3 or more within 12 months 4. Failure to respond (either complete or partial remission) even after CTX, MMF or CsA therapy combined with steroid * eGFR ≥ 60 ml/min/1.73 m2 * Provision of written informed consent by subject or guardian Exclusion Criteria: * Systemic disease * eGFR \< 60ml/min/1.73m2 * Diagnosed DM * Malignant tumors (except fully cured basal cell carcinoma) * Familial nephritic syndrome * History of significant gastrointestinal disorders (e.g. severe chronic diarrhea or active peptic ulcer disease) within 3 month prior to enter this study * Any Active systemic infection or history of serious infection within one month of entry or known infection with HIV, hepatitis B, or hepatitis C * Known hypersensitivity or contraindication to tacrolimus, corticosteroids * Participation in another clinic trial and/or receipt of investigational drugs within 4 weeks prior to screening * Pregnancy, nursing or use of a non-reliable method of contraception * Inability or unwillingness to provide written informed consent * Usage of immunosuppression therapy (MMF, CTX, CysA, MTX ect) for more than 1 week within 1 month prior to first randomization or intravenous MP Pulse treatment