Phospholipase‐A2 receptor antibody, 24 hours proteinuria, and serum albumin as indicators of cyclophosphamide efficacy in idiopathic membranous nephropathy

BACKGROUND: We aimed to evaluate cyclophosphamide efficacy in the treatment of idiopathic membranous nephropathy (IMN) and explore the efficacy of phospholipase‐A2 receptor antibody (PLA2R‐Ab), 24 hours proteinuria, and serum albumin in predicting 6‐ and 12‐month treatment effects. METHODS: A retrospective analysis was performed on 135 patients with IMN who followed up after treatment. The observation points were before, and after 3, 6, and 12 months of treatment. We collected clinical indicator data at each observation point and measured PLA2R‐Ab levels before and after 3‐month treatment. RESULTS: The remission rates at 3, 6, and 12 months of cyclophosphamide therapy for patients with IMN were 41.4, 74.8, and 76.1%, respectively. Patients in whom PLA2R‐Ab turned negative within 3 months had high remission rates at 3, 6, and 12 months after treatment (P < .05). PLA2R‐Ab change at 3 months had a strong correlation with 24 hours proteinuria change at 6 months. The change in albumin concentration before and after 3‐month treatment was an independent variable related to remission rate at 6 months, and 24 hours proteinuria change before and after 6‐month treatment was an independent variable related to remission rate at 12 months after treatment. CONCLUSION: Cyclophosphamide showed good efficacy at 3, 6, and 12 months for patients with IMN. Serum albumin change and PLA2R‐Ab change at 3 months can be used as indicators to predict remission at 6 months, respectively. Moreover, 24 hours proteinuria change at 6 months can predict remission at 12 months.