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Abstract: SA-PO720

Crescentic Glomerulonephritis due to Proteinase 3 (PR3) Anti-Neutrophil Cytoplasmic Autoantibody (ANCA) and IgA Mediated Anti-Glomerular Basement Membrane (GBM) Disease: A Rare Case of Double Identity

Session Information

Category: Glomerular Diseases

  • 1303 Glomerular Diseases: Clinical‚ Outcomes‚ and Trials


  • Siff, Melody L., Virginia Commonwealth University Health System, Richmond, Virginia, United States
  • Baig, Mirza Shahrukh, Richmond Nephrology Associates, Richmond, Virginia, United States
  • Kidd, Jason M., Virginia Commonwealth University Health System, Richmond, Virginia, United States

Crescentic glomerulonephritis due to co-existing ANCA associated vasculitis and Anti-GBM antibody disease is rare and often referred to as “double positive” disease. Most double positive cases involve myeloperoxidase (MPO) ANCA. Furthermore, anti-GBM disease generally manifests with linear staining IgG staining. We present a case of double positive disease with both PR3-ANCA and linear IgA staining of the glomerular basement membranes.

Case Description

A 73-year-old female presented to the hospital with acute kidney injury with a serum creatinine of 5.7 mg/dl. She had been treated with antibiotics for mastoiditis intermittently for 3 months. She was admitted to the hospital and underwent kidney biopsy. Serologic work up was significant for elevated PR3 ANCA. Biopsy was significant for crescentic glomerulonephritis and IgA and kappa linear staining along the GBM. No immune complexes were seen on electron microscopy. There was no evidence of diffuse alveolar hemorrhage. She was started on dialysis at presentation. After tissue diagnosis, she was started on glucocorticoids, plasma exchange and plan to begin cyclophosphamide. She has shown some renal recovery and dialysis is currently on hold.


Double positive ANCA and anti-GBM is rare combination with limited and conflicting data regarding treatment. Literature review revealed approximately one-third of patients with anti-GBM also had an associated ANCA, which was usually MPO and rarely PR3. We believe this is the fist described case of atypical anti-GBM (linear IgA) disease with dual positive PR3-ANCA. Due to the rarity of the co-existence, there are no treatment guidelines. Due to the severity of disease presentation, we are treating the patient aggressively with high dose steroids, plasma exchange and cyclophosphamide, which then should be followed by maintenance immunosuppression to prevent relapse of ANCA, especially prevalent in PR3.