Optimization of a Decision Formula for Optimal Timing of Immunosuppressive Therapy Initiation in Primary Membranous Nephropathy: A Multicenter Retrospective Cohort Study

Inclusion Criteria: * It meets one of the diagnostic criteria for PMN as stipulated in the KDIGO 2021 Clinical Practice Guidelines for the Management of Glomerular Diseases: patients with a clear diagnosis of PMN based on renal biopsy pathology or presenting with nephrotic syndrome and positive anti-PLA2R antibody detection (\>14RU/mL), and excluding secondary factors such as tumors, infections, drugs, and systemic autoimmune diseases. Exclusion Criteria: * (1) Patients who have received treatment with immunosuppressive medications other than oral prednisolone. (2) The time interval between the renal biopsy and the baseline measurement is longer than 3 years. (3) Initiate the use of immunosuppressive agents within 1 week after the diagnosis of PMN. (4) Participate in the immunosuppressive treatment trial during the follow-up period and be in the intervention group.