Abstract: FR-PO0815
Evaluation of Time-Resolved Fluoroimmunoassay (TRFIA) in Detecting Low-Titer Phospholipase A2 Receptor (PLA2R) Antibodies in Patients with Primary Membranous Nephropathy
Session Information
- Glomerular Diseases: Practice and New Concepts Shaping Modern Care
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Author
- Cheng, Hong, Division of Nephrology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
Background
The diagnosis of primary membranous nephropathy (PMN) relies on detecting anti-PLA2R antibodies. However, traditional ELISA methods may miss cases with low antibody titers. This study evaluated whether TRFIA improves sensitivity for detecting low-titer PLA2R-MN and explored the impact of clinical factors on test results.
Methods
We conducted a retrospective analysis of 210 MN patients with low-titer anti-PLA2R IgG (<20 RU/mL by ELISA) and 36 non-MN controls. All samples were retested using TRFIA. Univariate and multivariate logistic regression analyses identified independent risk factors for negative antibody results.
Results
TRFIA detected 87 positive cases (41.43%) among the 210 low-titer MN patients. The positive rate was significantly higher in the subgroup with ELISA values ≥2 RU/mL (60.53%) compared to those with values <2 RU/mL (18.75%). All 36 non-MN controls tested negative, confirming high specificity. The TRFIA-positive group had lower serum albumin (27.6 vs. 32.8 g/L, P<0.001), higher 24-hour urinary protein (3.9 vs. 3.2 g/24h, P=0.026), and a higher proportion of nephrotic syndrome (71.3% vs. 39.0%, P<0.001). Multivariate analysis identified a history of diabetes as an independent risk factor for negative test results (OR=2.499, 95% CI 1.054–5.924, P=0.038), indicating a 2.5-fold increased risk of false negativity. Diabetic patients were older (median 59 vs. 48 years) and had longer disease duration.
Conclusion
TRFIA effectively improves the detection rate of low-titer PLA2R-MN while maintaining excellent specificity. Diabetes history is a key factor associated with negative anti-PLA2R results. For seronegative patients with typical clinical features—especially elderly individuals with diabetes—retesting with high-sensitivity methods or combining serology with renal histopathology is recommended for accurate diagnosis.