Abstract: TH-PO0720
Can MRI Noninvasively Assess Kidney Histologic Activity and Damage in Patients with Lupus Nephritis?
Session Information
- Glomerular Innovations: Artificial Intelligence, Multiomics, and Biomarkers
November 06, 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
- Rovin, Brad, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
- Bell, Laura C., Genentech Inc, South San Francisco, California, United States
- de Crespigny, Alex J, Genentech Inc, South San Francisco, California, United States
- Pendergraft, William Franklin, Genentech Inc, South San Francisco, California, United States
- Cluceru, Julia, Genentech Inc, South San Francisco, California, United States
Background
A non-invasive way to monitor the response of the kidney to treatment remains an unmet need in lupus nephritis (LN). To address this need we postulated that magnetic resonance (MR) imaging may offer an approach to follow kidney inflammation and fibrosis in real-time. Here we report the relationship between diffusion MR imaging and kidney biopsy findings in a cohort of LN patients.
Methods
Patients with SLE who had a clinically-indicated kidney biopsy to diagnose or monitor LN consented to have MR scanning before the biopsy (n=7). The MR raw diffusion-weighted data was processed into primarily T2-weighted images (T2) (no diffusion-weighting) and apparent diffusion coefficient (ADC) maps (using all available diffusion-weightings). Region of interest delineation was performed using ITK-SNAP, loading in the T2 and manually placing 2x2 pixel squares in the axial plane where cortex and medulla could be resolved based on local image intensity; 80 pixels (40 cortex, 40 medulla) were placed for each image. Full kidney volumes were manually delineated. Correlations (Pearson r) were tested between the median ADC for cortex, medulla, and total kidney, and serum creatinine, eGFR, urine protein to creatinine ratio (uPCR) and activity and chronicity indices. An increase in ADC was assumed to represent increased tissue edema while a decrease in ADC was assumed to represent fibrosis.
Results
Cortical, medullary, and total kidney ADC was positively associated with serum creatinine and negatively associated with eGFR. There was no association of total kidney volume with eGFR. Cortical and medullary ADC were inversely associated with proteinuria, but there was no association between proteinuiria and total kidney ADC or volume. There was no association between activity index and ADC, but there was a positive association between cortical, medullary, and total kidney ADC and the chronicity index.
Conclusion
Diffusion MR metrics (ADC) in this initial investigation with a small sample size and cross-sectional design did not align with expectations regarding intra-renal inflammation, chronicity, or kidney function measures in LN. Although these data did not demonstrate a correlation with kidney histology in LN, this does not exclude the possibility that alternative MR metrics may be useful in following intra-renal changes in LN.
Funding
- Private Foundation Support