Anti-PLA2R antibody reduction as a predictor of treatment response in primary membranous nephropathy: a retrospective study

INTRODUCTION: Primary membranous nephropathy (PMN) is a leading cause of nephrotic syndrome in adults. Although proteinuria has been the conventional guiding parameter in disease monitoring, its limitations as a non-specific and delayed marker have led to the appeal of anti-phospholipase A2 receptor antibodies (PLA2R) as specific and sensitive indicators of disease activity and response to treatment. METHODS: This retrospective cohort study included 60 patients with biopsy-proven PMN and positive baseline anti-PLA2R antibodies who underwent treatment at the Multan Institute of Kidney Diseases. Anti-PLA2R levels were measured at baseline and at the 6-month follow-up using enzyme-linked immunosorbent assay (ELISA). Clinical remission was assessed using the standard proteinuria and renal function criteria. Statistical analyses included receiver operating characteristic (ROC) curves, logistic regression, and correlation assessments. RESULTS: Baseline anti-PLA2R levels were significantly lower in patients who achieved remission (p = 0.047), and 6-month levels showed a strong correlation with treatment response (p < 0.001). ROC analysis demonstrated good predictive accuracy with area under curve (AUC) of 0.707 (baseline) and 0.815 (6-month), identifying optimal remission cutoffs at 125.5 RU/mL and 37.75 RU/mL, respectively. Logistic regression analysis confirmed the baseline albumin level, 6-month anti-PLA2R, and proteinuria reduction as independent predictors of remission. CONCLUSION: Anti-PLA2R antibody levels at baseline and 6 months serve as robust predictors of treatment response in PMN and outperform proteinuria in early remission assessment. These findings support the integration of anti-PLA2R monitoring into standard clinical practice for personalized management and therapy adjustment in PMN.