Kidney Week

Abstract: FR-PO0667

Recurrent ANCA-Associated Vasculitis Exhibits Impaired Renal but Preserved Systemic Biomarker Recovery

Session Information

• Glomerular Diseases: Clinical, Outcomes, and Therapeutics Research - ANCA/FSGS
  October 23, 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

• Matías Martinez, Melvin Barish, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, CDMX, Mexico

Melvin Barish Matías Martinez, MD

• Santos, Julio Cesar, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, CDMX, Mexico

Julio Cesar Santos, MD

• Reyes-Moreno, Juan-Esteban, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, CDMX, Mexico

Juan-Esteban Reyes-Moreno

• Zavala Miranda, Fernanda, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, CDMX, Mexico

Fernanda Zavala Miranda, MS, MSc

• Mejia-Vilet, Juan M., Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, CDMX, Mexico

Juan M. Mejia-Vilet, MD, PhD

Background

There is interest in characterizing kidney function trajectories after renal ANCA-associated vasculitis (AAV) flares. Less is known regarding longitudinal changes in proteinuria, hemoglobin, and serum albumin, and the impact of recurrent flares on these trajectories. We aimed to assess recovery of renal and systemic biomarkers after renal AAV flares.

Methods

Retrospective cohort study including patients with a first renal AAV flare and ≥36 months follow-up. eGFR, urine protein-to-creatinine ratio (uPCR), hemoglobin, and serum albumin were recorded every 3 months. Longitudinal trajectories were modeled using linear, quadratic, or piecewise mixed-effects models according to best fit.

Results

We included 100 patients, 65% female, median age 52 years, with median follow-up of 7.2 years. Mean eGFR at first flare diagnosis was 40.9 ml/min/1.73m². eGFR showed marked early recovery during the first 3 months (+60.3 ml/min/1.73m²/year, 95%CI 52.5-68.2, p<0.001), followed by stable long-term kidney function (-0.28 ml/min/1.73m²/year, p=0.687). Proteinuria showed nonlinear decline with rapid early reduction followed by progressive flattening (linear b=-0.85 g/g/year; quadratic b=+0.18g/g/year², both p<0.001). Serum albumin increased progressively (+0.27 g/dL/year, 95%CI 0.24-0.31, p<0.001). Hemoglobin demonstrated rapid early recovery (+7.8g/dL/year, 95%CI 6.9-8.8, p<0.001), followed by slower long-term improvement (+0.34 g/dL/year, 95%CI 0.22-0.47, p<0.001). Twenty-eight patients had a recurrent renal flare. Recurrent flares were associated with lower baseline eGFR (-13.5 ml/min/1.73m² vs first flare, p=0.035) and significant chronic renal decline during follow-up (-3.75 ml/min/1.73m²/year, 95%CI -6.44 to -1.05, p=0.007). Proteinuria improvement was attenuated after recurrent flare (p<0.001). Hemoglobin showed reduced early recovery after recurrent flare (p<0.001), while serum albumin trajectories remained similar.

Conclusion

Renal and systemic biomarkers show distinct recovery kinetics after renal AAV flares. Recurrent flares selectively impair trajectories of eGFR, proteinuria, and hemoglobin, while albumin recovery remains preserved.

Fig 1. eGFR (left) and uPCR (right) trajectories in initial vs recurrent flare