Abstract: SA-PO0717
Fibrillary Glomerulonephritis with Focal Crescents and Concurrent c-ANCA, p-ANCA, and Myeloperoxidase (MPO) Positivity
Session Information
- Glomerular Diseases: Complement-Mediated Glomerulopathies and Infection-Related GN
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
- Naeem, Shanzae, Piedmont Macon Medical, Macon, Georgia, United States
- Robinson, Nicholas, Piedmont Macon Medical, Macon, Georgia, United States
- Sakhalkar, Om Vishwas, Piedmont Macon Medical, Macon, Georgia, United States
Introduction
Fibrillary glomerulonephritis is a rare glomerular disease characterized by Congo red–negative fibrillary deposits and now reliably identified by DNAJB9 staining. Crescentic lesions occur in a minority of cases, while ANCA positivity is rare and most commonly MPO-associated. We report a unique case of DNAJB9-positive FGN with focal crescents and triple ANCA positivity.
Case Description
A 74-year-old male with COPD, hypertension, CKD stage 3B, presented with dyspnea, and fatigue. Laboratory evaluation showed creatinine 6.76 mg/dL, BUN 62 mg/dL, nephrotic-range proteinuria (10.8 g/day), albumin 3.0 g/dL, and marked hematuria. Complements were normal. Serologies revealed c-ANCA 1:320, p-ANCA 1:320, MPO antibody 3.1, PR3 negative, ANA negative, and anti-GBM negative. SPEP/UPEP were negative. Kidney biopsy demonstrated mesangial expansion, segmental sclerosis, focal necrotizing lesions, and cellular/fibrocellular crescents nonsclerotic glomeruli with moderate interstitial fibrosis/tubular atrophy. Immunofluorescence showed smudgy mesangial/capillary loop IgG, C3. Congo red was negative. DNAJB9 staining was diffusely positive, and electron microscopy demonstrated randomly oriented nonbranching fibrils consistent with FGN. The patient received pulse methylprednisolone followed by prednisone taper and rituximab.
Discussion
This case discusses an unusual overlap of DNAJB9-confirmed FGN with crescentic/necrotizing injury and ANCA positivity. While ANCA positivity in FGN is rare, the presence of high-titer ANCA serologies together with crescents and necrosis raised concern for superimposed ANCA-mediated inflammation. Recognition of these overlapping features is important because they may influence immunosuppressive management and renal outcomes.