Exploration of Factors Influencing Early-Onset Acute Kidney Disease in Patients with Idiopathic Membranous Nephropathy and Development of a Risk Scoring System

Background: Idiopathic membranous nephropathy (IMN) is an immune-mediated glomerular disease. We have observed in clinical practice that some IMN patients experience rapid progression of renal function during the early stages of the disease, reaching the criteria for acute kidney disease (AKD). This study aims to explore these factors and establish a scoring prediction system based on multivariate analysis to help identify high-risk patients early. Methods: A retrospective analysis was conducted on patients diagnosed with IMN through renal biopsy at the Department of Nephrology, Beijing Anzhen Hospital, Capital Medical University, who had regular follow-ups. Patients were divided into two groups: those who developed AKD within the first three months after diagnosis and those who did not. Multivariate logistic regression analysis was used to identify factors influencing AKD development. Based on the odds ratios (OR) of independent risk factors and clinical specifics, scores were assigned to each factor to develop a risk scoring system. Results: Compared to IMN patients who did not develop AKD, those who did were more likely to be female, older, have a higher proportion of hypertension, lower urine osmolality, higher prevalence of anemia, lower serum albumin levels, worse renal function, and higher serum anti-PLA2R antibody titers. Pathologically, they had a higher proportion of ischemic glomeruli and higher tissue C3 positivity rates. Treatment-wise, a higher proportion used diuretics. After adjusting for multiple factors, female gender, age, hypertension, serum albumin levels, anemia, and tissue C3 positivity were identified as independent risk factors for AKD. Based on these results, we established a risk scoring system for early AKD development in IMN patients: low-risk (< 9 points), moderate-risk (9–15 points), and high-risk (≥ 15 points). The early AKD incidence rates for these groups were 5.9%, 24.9%, and 63.5%, respectively. Conclusion: IMN patients who develop AKD have poorer long-term renal outcomes. The established risk scoring system may assist clinicians in identifying high-risk AKD patients early and implementing preventive interventions to improve long-term renal prognosis.