Abstract: FR-PO0871
Evaluating the Appropriate Time Point to Assess Remission in IgAN: Landmark Analysis Using a Multicenter Cohort
Session Information
- Glomerular Outcomes: From Proteinuria to Prognosis
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Matsuzaki, Keiichi, Kitasato University School of Medicine, Sagamihara, Japan
- Suzuki, Hitoshi, Juntendo University Urayasu Hospital, Urayasu, Japan
- Higuchi, Atsushi, Tokyo University of Science Graduate School of Engineering, Tokyo, Japan
- Sozu, Takashi, Tokyo University of Science, Tokyo, Japan
- Hirano, Keita, Jikei University School of Medicine, Tokyo, Japan
- Yasuda, Yoshinari, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Yasuda, Takashi, Naruse Kidney Clinic, Machida, Japan
- Yokoo, Takashi, Jikei University School of Medicine, Tokyo, Japan
- Suzuki, Yusuke, Juntendo University Faculty of Medicine, Tokyo, Japan
Background
We previously proposed clinical remission criteria for IgA nephropathy (IgAN) (Clin Exp Nephrol, 2014) and confirmed their prognostic value (Clin Exp Nephrol, 2021). Furthermore, using a multi-state model, we visualized remission transitions in hematuria and proteinuria (Kidney Week 2024). Based on these findings, the timing of improvement in urinary abnormalities varies among individuals, which may influence the prognostic utility of remission. This study aimed to evaluate the appropriate time point to assess remission that best reflects long-term renal outcomes in IgAN.
Methods
We analyzed 926 Japanese adults with IgAN (male 50.3%, median age 35.0) from a reported cohort (JAMA Netw Open. 2019). Baseline characteristics were evaluated at renal biopsy, and clinical data were collected longitudinally. We applied a landmark analysis at 0.5 year intervals post-renal biopsy, including only patients under observation at each point. The primary endpoint was defined as a 1.5-fold increase in serum creatinine from baseline. Cox models at each landmark adjusted for age, mean arterial pressure (MAP), and eGFR. Model discrimination was assessed with Uno’s C-statistics.
Results
The number of events at each time point were as follows: 0.5 year: 5 (0.5%), 1.0 year: 12 (1.3%), 1.5 year: 21 (2.3%), 2.0 year: 29 (3.1%), 2.5 year: 35 (4.1%), 3.0 year: 40 (4.3%). In models with remission status as a time-fixed covariate, C-statistic improved with longer follow-up, though gaines plateaued beyond the 2.0-year landmark. The values (95% CI) were as follows: 0.5 year: 0.64 (0.60-0.69), 1.0 year: 0.68 (0.61-0.74), 1.5 year: 0.71 (0.65-0.78), 2.0 year: 0.75 (0.68-0.83), 2.5 year: 0.76 (0.68-0.83), 3.0 year: 0.78 (0.70-0.86)). After adjusting for age, MAP, and eGFR, discrimination remained similar: 0.5 year: 0.80 (0.76-0.86), 1.0 year: 0.82 (0.77-0.87), 1.5 year: 0.84 (0.79-0.90), 2.0 year: 0.85 (0.81-0.90), 2.5 year: 0.86 (0.81-0.91), 3.0 year: 0.88 (0.82-0.93)).
Conclusion
We demonstrated that remission assessment at 2 years after renal biopsy represents a clinically meaningful and prognostically informative time point in patients with IgAN, as predictive performance stabilized thereafter. This supports its use in appropriate evaluation and long-term outcome prediction.