Tacrolimus Monotherapy for Idiopathic Membranous Nephropathy (IMN)

Inclusion Criteria:

1. Age: 18 - 80 years;

2. Those whose clinical manifestation and renal biopsy pathologic diagnosis are IMN (Stages I-IV) with secondary membranous nephropathy excluded;

3. Those who meet any of the following high-risk IMN standards:

• Urinary protein>8g/24h

• Serum albumin<25g/l

• Serum PLA2R levels are 5 times higher than normal

• eGFR decline rate after confirmed IMN within 6-12 months is ≥30%

• Patients with serious complications: pulmonary embolism, lower extremity staticVein thrombosis/embolism, acute renal injury, etc.

4. Those without reaching the above high-risk IMN standard, but their course of diseaseis >6 months without spontaneous remission,and still present nephrotic syndrome;

5. Patients who have signed the informed consent forms.

Exclusion Criteria:

1. Those whose kidney pathological manifestation of interstitial fibrosis is >30%;

2. Those who are positive in active Hepatitis B (including HBsAg, HBeAg and HBcAb orHBsAg, HBeAb and HBC) or serological indexes (HBsAg or/and HBeAg or/and HBcAb) orinfected with Hepatitis C, tuberculosis, cytomegalovirus, severe fungal or HIVinfection;

3. Those who suffer from untreated active digestive tract ulcer within 3 months beforerandom grouping;

4. Those who suffer from uncured malignant tumor for less than 5 years

5. Those who received glucocorticoid (prednisone or prednisolone), mycophenolatemofetil,tacrolimus, cyclosporine A and other drugs for treatment within 3 months before screenwith a course of treatment exceeding 4 weeks or those who received cyclophosphamide (accumulated dose>1.0g);

6. Those whose ALT, AST or total bilirubin content goes beyond 1.5 times above normalupper limit;

7. Those who suffer from combined critical complications such as serious infection orother severe organ disease or dysfunction;

8. Pregnant or lactating women;

9. Those who are known to be allergic to drugs under trial or relevant products;

10. Those who participated in other clinical trials within 3 months before inclusion;

11. The patients who cannot comply with the research proposal as determined by thesupervising physician. Exit criteria

12. Those with incomplete or partial relieved proteinuria for 6 months after treatment;

13. Patients or their legal guardians voluntarily requests to withdraw;

14. Those against the inclusion criteria and exclusion criteria;

15. Those who need to take medications prohibited by the trail;

16. Those with poor compliance or stopping the drug for over 2 weeks;

17. Those with uncontrollable infection;

18. Those whit elevated blood glucose during the treatment, which is still difficult tocontrol after routine treatment by endocrinologists;

19. In the TAC group, the eGFR decreased by >30%, the TAC dose was halved. And the drugconcentration and renal function were reviewed after 2 weeks. If the eGFR decreased by <30%, it will continue to be used; if the eGFR still decreased by >30%, the TAC dosecontinues to halve, or give a minimum dose of 0.5mg / d. And the drug concentrationand renal function were reviewed after 2 weeks. If the eGFR decreased by <30%, TACwill continue to be used, otherwise stop the drug;

20. Those whose ALT, AST or bilirubin rises to more than 2 times the upper limit of normalvalue after treatment, and continues to increase for 2 weeks; those whose ALT, AST orbilirubin rises to more than 2 times the upper limit of normal value after 2 weeks oftreatment with liver protection, the drug will be discontinued. If it cannot berecovered after 2 weeks, the patient will withdraw;

21. Those with other unexplained severe comorbidities;

22. Those with pregnancy during treatment;

23. For security reasons, the research sponsor proposed to stop the study;