Abstract: FR-PO0779
An Unusual Case of Renal-Limited ANCA-Associated Vasculitis: Chasing the Big Vessel
Session Information
- Glomerular Diseases: ANCA Vasculitis, Anti-GBM Disease, and Crescentic GN
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
- Mishra, Ishani, University of Alabama at Birmingham Health System, Birmingham, Alabama, United States
- Bhatia, Girik, University of Alabama at Birmingham Health System, Birmingham, Alabama, United States
- Fatima, Huma, University of Alabama at Birmingham Health System, Birmingham, Alabama, United States
- Morales-Alvarez, Martha Catalina, University of Alabama at Birmingham Health System, Birmingham, Alabama, United States
Introduction
ANCA-associated vasculitis is a small-vessel vasculitis characterized by autoantibodies against proteinase-3 or myeloperoxidase. Kidney involvement classically exhibits pauci-immune necrotizing crescentic glomerulonephritis, often associated with other systemic manifestations. We present an unusual case of renal-limited PR3-ANCA vasculitis with isolated intimal arteritis on kidney biopsy.
Case Description
A 71-year-old female presented to the ED with a near-syncopal event, afib with RVR, and AKI. Creatinine was 4.3 mg/dL, associated with nephrotic-range proteinuria and pyuria. Baseline creatinine was 3.0 mg/dL a month ago and 1.2 mg/dL 9 months before. There was an initial concern for AIN in light of multiple rounds of antibiotics and NSAID use. Extensive serologic testing revealed positive p-ANCA and PR3. Kidney biopsy showed a focal area of intimal arteritis and mild tubular injury, with no active glomerular disease (Fig 1). High-dose steroids, plasmapheresis, and cyclophosphamide were initiated. Due to concerns for excessive immunosuppression and hemorrhagic cystitis, she was transitioned to rituximab and avacopan. Kidney function improved, with creatinine down to 1.9 mg/dL. Despite initial recovery, she was rehospitalized multiple times for infections and died a few months later from septic shock.
Discussion
This case demonstrates the diagnostic challenges in a patient with multiple insults and an atypical presentation of AAV. The coexistence of p-ANCA positivity with PR3 elevation further increased diagnostic uncertainty, underscoring the importance of renal biopsy for definitive diagnosis. Her biopsy findings of isolated intimal arteritis without glomerular involvement represent an atypical finding with uncertain prognosis. Ultimately, her course reflected the delicate balance between effective immunosuppression and the heightened risk of infection in vulnerable individuals.