Abstract: FR-PO0650
Nephrin Antibody-to-IgG Ratio Predicts Relapse-Prone Podocytopathy: A Single-Center, Retrospective, Observational Study
Session Information
- Glomerular Diseases: Clinical, Outcomes, and Therapeutics Research - ANCA/FSGS
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
Authors
- Nakai, Anna, Tokyo Joshi Ika Daigaku, Shinjuku, Tokyo, Japan
- Shirai, Yoko, Tokyo Joshi Ika Daigaku, Shinjuku, Tokyo, Japan
- Manabe, Shun, Tokyo Joshi Ika Daigaku, Shinjuku, Tokyo, Japan
- Ushio, Yusuke, Tokyo Joshi Ika Daigaku, Shinjuku, Tokyo, Japan
- Takahashi, Rina, Tokyo Joshi Ika Daigaku, Shinjuku, Tokyo, Japan
- Miura, Kenichiro, Tokyo Joshi Ika Daigaku, Shinjuku, Tokyo, Japan
- Hattori, Motoshi, Tokyo Joshi Ika Daigaku, Shinjuku, Tokyo, Japan
- Hoshino, Junichi, Tokyo Joshi Ika Daigaku, Shinjuku, Tokyo, Japan
Background
Anti-nephrin autoantibodies are key pathogenic factors in minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). However, unadjusted serum titers are prone to false negatives due to massive urinary loss and rapid clearance post-treatment. We investigated whether the anti-nephrin antibody-to-IgG ratio overcomes these confounders to predict relapse-prone disease.
Methods
We analyzed 44 adult patients (37 MCD, 7 FSGS). Cutoffs for unadjusted titers (226 U/mL) and the IgG-adjusted ratio (30 U/mg) followed previous criteria (Miura K, et al. KI Rep 2026). Positivity rates were compared between untreated and post-treatment groups. Clinical outcomes were classified into favorable outcome vs. relapse-prone disease (frequent relapsing/steroid-dependent nephrotic syndrome [FRNS/SDNS]). Analyses utilized Fisher's exact and McNemar's tests.
Results
Overall, unadjusted titers identified 12 positive cases (27.3%), whereas the IgG-adjusted ratio identified 32 (72.7%), salvaging 20 false-negative cases. In the post-treatment group (n=31), unadjusted positivity dropped to 25.8% (8 cases), but the adjusted ratio maintained a robust 74.2% (23 cases) positivity (P<0.001). For outcomes, unadjusted positivity in the relapse-prone group (n=15) was just 6.7% (1 case) vs. 60.0% (9 cases) using the adjusted ratio (P=0.16) (Table 1). Crucially, the adjusted ratio captured 100% (7/7) of patients who developed SDNS, identifying high-risk cases missed by unadjusted titers.
Conclusion
Unadjusted anti-nephrin titers are highly susceptible to treatment and urinary loss-induced false negatives. The antibody-to-IgG ratio reflects true immunological activity, providing an effective baseline biomarker for identifying patients at risk of relapse-prone disease.