Abstract: SA-PO0788
Lupus Nephritis in Japan: A Comparative Study Using the Japan Renal Biopsy Registry over the Past Decade
Session Information
- Glomerular Research: Design, Registries, Surveys, and Epidemiology
November 08, 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
- Ikeuchi, Hidekazu, Department of Nephrology and Rheumatology, Gunma University, Maebashi, Japan
- Ozeki, Takaya, Department of Nephrology, Nagoya University, Nagoya, Japan
- Maruyama, Shoichi, Department of Nephrology, Nagoya University, Nagoya, Japan
- Tsuboi, Naotake, Department of Nephrology, Fujita Health University, Toyoake, Japan
- Tsuji, Takahiro, Department of Pathology, Sapporo City General Hospital, Sapporo, Japan
- Sugiyama, Hitoshi, Kawasaki Medical School General Medical Center, Okayama, Japan
- Hiromura, Keiju, Department of Nephrology and Rheumatology, Gunma University, Maebashi, Japan
Background
The treatment landscape for systemic lupus erythematosus (SLE) and lupus nephritis (LN) has been changing. We aimed to examine changes over a decade in the clinical and pathological features of LN at the time of renal biopsy in Japan.
Methods
We compared 682 patients undergoing first-time biopsies and 128 undergoing repeat biopsies registered in the Japan Renal Biopsy Registry (J-RBR) between 2018 and 2021, with 331 patients registered for first-time biopsies between 2007 and 2012. The analysis focused on patients registered as having LN at the time of initial renal biopsy.
Results
Clinical characteristics of patients at the time of first biopsy during 2007–2012 and 2018–2021 are shown in Table and Figure 1A. The mean age at biopsy increased from 38.6 ± 15.1 to 41,6 ± 17.7, indicating an overall aging trend, and the proportion of patients aged ≥60 years approximately doubled from 10.6% to 19.3%. Histopathologically, compared with a decade ago, the proportion of Class IV (±V) decreased, while Class II and Class III (±V) increased significantly (Figure 1B). Further analysis of Class III/IV subtypes revealed an increase in pure Class III and a decrease in pure Class IV (Figure 1C).
Conclusion
A comparison of first-time renal biopsies over the past decade in Japan revealed an aging patient population and a notable shift in histological classification, with decreases in Class IV and increases in Class II and Class III LN.