Kidney Week

Abstract: SA-PO0828

Association Between Percentage Decline in Proteinuria and Outcomes: Results from PARASOL FSGS

Session Information

• Glomerular Diseases: Management, Evolving Strategies, and Practice-Changing Advances
  October 24, 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

• Smith, Abigail R., Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States

Abigail R. Smith, PhD

• Helmuth, Margaret, University of Michigan, Ann Arbor, Michigan, United States

Margaret Helmuth, MA

• Derebail, Vimal K., The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States

Vimal K. Derebail, MD, MPH, FASN

• Angeletti, Andrea, Istituto Giannina Gaslini, Genoa, Liguria, Italy

Andrea Angeletti, MD, PhD

• Schaefer, Franz, Universitat Heidelberg, Heidelberg, BW, Germany

Franz Schaefer, MD, PhD

• Caravaca-Fontan, Fernando, Hospital Universitario 12 de Octubre, Madrid, Community of Madrid, Spain

Fernando Caravaca-Fontan, MD, PhD

• Jauhal, Arenn Singh, University of Toronto, Toronto, Ontario, Canada

Arenn Singh Jauhal, MD, MS, MSc

• Khalid, Myda, Indiana University School of Medicine, Indianapolis, Indiana, United States

Myda Khalid, MD, FASN

• Modi, Zubin J., University of Michigan, Ann Arbor, Michigan, United States

Zubin J. Modi, MD, MS

• Damashek, Laurel J., International Society of Glomerular Disease, Florence, Massachusetts, United States

Laurel J. Damashek, MA

• Kretzler, Matthias, University of Michigan, Ann Arbor, Michigan, United States

Matthias Kretzler, MD

• Mariani, Laura H., University of Michigan, Ann Arbor, Michigan, United States

Laura H. Mariani, MD, MS, FASN

Group or Team Name

• the PARASOL consortium

Background

Proteinuria is becoming a more prevalent primary endpoint in clinical trials of FSGS; however, the definition of this endpoint varies. Prior work in PARASOL demonstrated associations between binary responder endpoints and kidney failure. The objective was to characterize the relationship between continuous proteinuria and long-term outcomes.

Methods

The PARASOL consortium harmonized datasets from 9 registries. Eligible participants had biopsy-proven FSGS, at least 1 UPCR≥1.5 g/g, and eGFR≥30 ml/min/1.73m². Change from index to UPCR 6-12m and 12-24m post-index was analyzed as difference in log(UPCR) and associations with kidney failure after 12 or 24m and eGFR slope over 24m were assessed using landmark Cox regression and linear mixed effects regression models, respectively, adjusted for age, sex, index eGFR and UPCR, and data source.

Results

1499 participants were included; median (IQR) age was 21 (9, 43). Median (IQR) eGFR and UPCR at index were 83 (56, 111) ml/min/1.73m² and 3.7 (2.2, 6.9) g/g, respectively. Median reduction in UPCR was 55% at 12m and 60% at 24m. Each one unit increase in log difference in UPCR (~63% decline) was associated with a 42% (12m) and 51% (24m) lower hazard of kidney failure (HR₁₂=0.58 95% CI 0.52-0.64; HR₂₄=0.49 95% CI 0.44-0.56). Each 50% reduction in UPCR was associated with a 32% (12m) and 39% (24m) lower hazard of kidney failure (Figure). eGFR decline over 24m was attenuated by larger reductions in UPCR at 12 and 24m; each 50% decline in UPCR at 12 and 24 months resulted in a 1.1 (95% CI 0.69-1.46) and 0.92 (95% CI 0.55-1.28) ml/min/1.73m²/yr slower decline in eGFR, respectively.

Conclusion

Relative decline in UPCR was associated with reduction in risk of kidney failure and slower decline in eGFR in this broad population of patients with FSGS, lending clinical interpretation to this quantity as a primary endpoint.

Funding

• Private Foundation Support