Abstract: TH-PO0692
SuperNAT: A Novel Sensitive Assay for Detection of Low-Abundance Nephrin Autoantibodies, IgG, and IgM
Session Information
- Glomerular Diseases: Immunopathogenesis and Targeted Therapeutics
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology
Authors
- Yue, Yan, AlloDX (Shanghai) Biotech Co, Ltd., Shanghai, China
- Cuello Garcia, Haider, AlloDX (Shanghai) Biotech Co, Ltd., Shanghai, China
- Li, Lu Peil, AlloDX (Shanghai) Biotech Co, Ltd., Shanghai, China
- Liu, Haitao, AlloDX (Shanghai) Biotech Co, Ltd., Shanghai, China
- Jiang, Tingya, AlloDX (Shanghai) Biotech Co, Ltd., Shanghai, China
- Shi, Haifeng, AlloDX (Shanghai) Biotech Co, Ltd., Shanghai, China
Background
Nephrin antibodies at low-abundance may be challenging to be detected due to the interference of other proteins in the bloodstream, which renders the threshold in the determination of anti-nephrin antibody positivity at a relative high level around 187 U/mL in conventional ELISA. The IgG immunoprecipitation-enhanced ELISA has been developed to increase the signal noise ratio, however, it is unable to detect IgM. Moreover, the binding capacity of Nephrin antibodies to different epitopes remains unexplored. Therefore, this study developed a novel Nephrin antibody detection approach called Super Nephrin Antibody Trap (SuperNAT)
Methods
The samples from 117 healthy and 40 patients with MCD and post-transplant FSGS were used. The detection of anti-nephrin IgG and IgM employed Biotin-conjugated recombinant Nephrin antigen. Moreover, antigen-free well serves the control for each sample in ELISA, and the optical density (OD) value was subtracted. The resistance of SuperNAT assay to common interfering substrates triglycerides and erythrocytes was evaluated using Nephrin polyantibody mixed with triglycerides (1.7–5.6 mM) and erythrocytes (0.1–1.0%). Moreover, six epitopes were predicted via Bepipred 3.0 and DiscoTope 3.0, and six epitopes with high-confidence were identified and validated using Nephrin IgG-positive 23 samples and 6 healthy controls
Results
SuperNAT assay revealed Nephrin antibodies level showed a skewed distribution (coefficient is 1.38, mode is 2.61<median 9.22<mean 12.2) in healthy control，significantly higher in patients (59.71 vs 9.22 U/mL, p<0.0001). Moreover, with the threshold set at 45 U/mL (99th percentile), the Nephrin antibody positive detection rate was 55% in patients, representing a 48.6% improvement over conventional ELISA. SuperNAT tolerated triglycerides up to 3.65 mM and 1% erythrocytes without significant interference. In addition, Nephrin IgM antibodies were detected in 15% of patients, half of whom were IgG-negative, furthermore, We further identified two Nephrin regions 15 aa–29 aa and 778 aa–793 aa as potential epitopes with strong antibody-binding capacity
Conclusion
SuperNAT is a highly sensitive method for the detection of both IgG and IgM. IgM testing may be warranted in IgG-negative patients. The identified epitopes may correlate with disease progression, warranting further investigation