Abstract: FR-OR029
US Patients with IgAN and Low Proteinuria Have Significantly Better Kidney Survival than Participants in the UK RADAR Study
Session Information
- Glomerular Disease Outcomes: Measuring What Matters
November 07, 2025 | Location: Room 310A, Convention Center
Abstract Time: 04:40 PM - 04:50 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Patel, Nilang G., Virginia Commonwealth University, Richmond, Virginia, United States
- Silvey, Scott, Virginia Commonwealth University, Richmond, Virginia, United States
- Athavale, Ambarish, University of California San Diego, La Jolla, California, United States
- Kidd, Jason M., Virginia Commonwealth University, Richmond, Virginia, United States
Background
Proteinuria predicts kidney failure in IgAN. UK RADAR data suggests kidney failure risk even with Timed average proteinuria < 0.5 gm but US population data is lacking.
Methods
A retrospective cohort analysis of the TriNetX database (2015-2023) identified patients with primary IgAN, excluding those with secondary causes, prior kidney transplants, ESRD, or baseline eGFR ≤ 15 ml/min. Patients were categorized based on timed average Urine protein-creatinine ratio (UPCR): Group 1: < 0.5 g/g, Group 2: 0.5-1 g/g, Group 3: 1-2 g/g, Group 4: 2-3 g/g, and Group 5: >3 g/g. Composite kidney failure outcome was defined as either eGFR ≤ 15, >40% decline in eGFR, initiation of dialysis, or death. KM survival analysis and CoxPH models assessed the relationship between Timed average UPCR and outcomes, with UPCR changes during follow-up factored into the CoxPH model to recalibrate kidney failure risk.
Results
745 adults with primary IgAN, (mean age 43.5(16) yrs, 58.3% Male, 68.3% white) were analyzed. Group 1, 2, 3, 4, 5 has 269 (36.1%), 163 patients (21.9%),149 (20.0%), 71 (9.5%), and 93 (12.5%) patients, respectively. The mean follow-up time was 5.39 yrs, and 17.3% reached the composite outcome. Higher UPCR was significantly associated with a higher risk of the composite outcome (fig 1a), however, unlike the RADAR study, risk of composite outcome was not different for proteinuria < 0.5 gm and 0.5-1 gm. Patients with < 0.5 gm proteinuria had 5.9% risk of kidney failure as compared to 20% reported by the RADAR study. At follow-up, one group decrease in proteinuria was associated with a reduction in the absolute risk of composite outcome (adj. HR: 0.73 [0.60-0.88], p=0.001). Figure 1b
Conclusion
In a US IgAN population, UPCR > 1g/g is linked to worse kidney outcomes. Improvement in proteinuria during follow-up significantly lowers the risk of adverse outcomes.