Combination of Rituximab and Cyclosporine in the Treatment of Primary Membranous Nephropathy

Inclusion Criteria:

1. Age 18-80 years.
2. Primary membranous nephropathy confirmed by renal biopsy.
3. 24-hour urinary protein quantification > 5.0 g/24h and serum albumin < 30 g/L after at least 3 months of treatment with RAAS blockers.
4. eGFR ≥ 40 mL/min/1.73 m².
5. Well-controlled blood pressure (≤140/90 mmHg) in the recent 3 months.
6. Signed informed consent form.

Exclusion Criteria:

1. Secondary causes of membranous nephropathy, such as that secondary to systemic lupus erythematosus, malignant tumors, hepatitis B virus infection, heavy metal poisoning;
2. Coexistence of other types of kidney diseases;
3. Use of rituximab within the past 12 months;
4. Use of corticosteroids, cyclophosphamide, cyclosporine, mycophenolate mofetil, or leflunomide within the past 3 months;
5. Active infection: active tuberculosis, HBsAg positivity or HBV-DNA indicating viral replication, positive HCV antibody, HIV infection;
6. New-onset cardiovascular or cerebrovascular diseases within the past 3
7. Severe liver disease: AST and ALT > 3 times range upper limit ;
8. Uncontrolled severe hypertension;
9. Newly diagnosed or recurrent malignant tumors within the past 5 years;
10. Coexistent autoimmune diseases;
11. Pregnancy, lactation, or recent plans for pregnancy;
12. Life expectancy less than 12 months;
13. Participation in other clinical trials within the past 3 months;
14. Unwillingness to sign the informed consent form;
15. Any other condition deemed unsuitable for the study by the investigator.