Clinical Study of Rituximab Combined With Corticosteroids or Rituximab Monotherapy in the Treatment of Primary Membranous Nephropathy

Inclusion Criteria 1. Men and women aged 18-75 years; 2. Patients diagnosed as primary membranous nephropathy (PMN) by renal biopsy; 3. After treatment with ACE inhibitors or ARBs for at least 3 months, the following two points were met (unless intolerance to ACE inhibitors or ARBs, contraindications, hypotension that may cause side effects, or the investigator judged that the patient was not suitable for RAS inhibitors): (1) Those who have an average 24-hour urine protein ≥ 3.5g twice a week, or an average 24-hour urine protein ≥ 5g twice in 14 days, the requirement of RASi for at least 3 months is not required (2) Blood pressure≤ 130/80mmHg, 4. Glomerular filtration rate (eGFR) ≥30mL/min/1.73m2 (calculated according to the CKD-EPI formula) 5. If female, must be postmenopausal or postoperatively infertile or on medical contraception (considering the potential risk of thromboembolism in patients with kidney disease); 6. Subjects voluntarily signed the informed consent form; Exclusion Criteria: 1. Patients with type 1 diabetes mellitus or type 2 diabetes mellitus complicated with diabetic nephropathy. Patients with a recent history of steroid-induced diabetes were eligible if renal biopsies show no evidence of secondary diabetic nephropathy within 6 months before the screening period 2. Patients with secondary membranous nephropathy (such as hepatitis B and C, systemic lupus erythematosus, drug therapy, malignant tumors and other secondary causes); 3. Previous treatment with rituximab, steroids, alkylating agents, calcineurin inhibitors, synthetic ACTH, mycophenolate (MMF), and azathioprine; 4. Receipt of any other study medication (within the last month); 5. Suspected or known allergy or immune reaction to rituximab, corticosteroids or any of their components (including excipients); 6. Active infection, such as active hepatitis B or hepatitis C, tuberculosis (evidence of active tuberculosis infection within 1 year), or human immunodeficiency virus HIV infection (positive for anti-HIV antibodies), etc. 7. A history of immunodeficiency, including other acquired or congenital immunodeficiency diseases, or organ transplantation; 8. Females with a positive pregnancy screening test or lactating or planning to become pregnant in the next 24 months. Female or male patients who were unwilling to use contraceptive methods throughout the study; 9. A history of mental illness; 10. Laboratory tests that meet the following criteria need to be excluded: (1) Hemoglobin\<80g/L; (2) Platelet \< 80×109/L; (3) Neutrophil \<1.0×109/L; (4) Aspartate aminotransferase (AST) or amino aminotransferase (ALT) \> 2.5× upper limit of normal except in relation to the primary disease; 11. Very high-risk patients: presenting with life-threatening nephrotic syndrome, or unexplained rapid deterioration of renal function 12. Any patient judged by the investigator to be unsuitable for inclusion in the trial.