Baseline anti-PLA2R antibody titer predicts treatment response and renal outcomes in rituximab-treated membranous nephropathy

Introduction As rituximab (RTX) has become a first-line therapy for idiopathic membranous nephropathy (IMN), identifying baseline predictors of treatment response is crucial for personalized management. This study was conducted to evaluate whether baseline anti-PLA2R titer could predict treatment response and renal outcomes following RTX therapy. Methods A single-center retrospective cohort study was conducted on 69 patients with PLA2R-associated membranous nephropathy treated with RTX. The primary outcome was partial/complete remission. Secondary outcomes included rapid renal function decline (eGFR decrease ≥3 mL/min/1.73m 2 /year) and renal composite endpoint (≥ 30% eGFR decline or end-stage kidney disease). Cox proportional hazards models were used to assess associations between log-transformed baseline anti-PLA2R levels and clinical outcomes. Results Over a median follow-up of 25.1 months, remission was achieved in 78.3% of patients with a median time of 6.8 months. Higher baseline log(anti-PLA2R) levels were significantly associated with a lower probability of remission (adjusted HR per 1-log increment: 0.71, 95% CI 0.58–0.87) and a higher risk of rapid renal function decline (adjusted HR per 1-log increment: 1.47, 95% CI 1.04–2.07). Patients with anti-PLA2R ≥402 RU/mL exhibited a 6.0-fold higher risk of rapid renal function decline (95% CI 1.88–19.15). Conclusions The findings underscored the potential of baseline anti-PLA2R titers in predicting treatment response and renal outcomes, thereby facilitating risk stratification and personalized treatment intensification in MN.