Abstract: SA-PO0732
Fibrillary Glomerulonephritis Presenting as Isolated Microscopic Hematuria with Minimal Proteinuria
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
- Al Assaad, Rami, University of South Florida, Tampa, Florida, United States
- Yi, Jia, University of South Florida, Tampa, Florida, United States
Introduction
Fibrillary glomerulonephritis (FGN) is a rare glomerular disease characterized by non-amyloid fibrillary deposits and DNAJB9 positivity. It typically presents proteinuria, hematuria, and progressive kidney dysfunction. Cases with minimal proteinuria and without significant renal dysfunction are uncommon and may delay diagnosis.
Case Description
A 67-year-old woman with a history of hypertension, non-ischemic cardiomyopathy, COPD and prior DVT was evaluated for persistent microscopic hematuria initially identified in 2018. Extensive urologic evaluation, including cystoscopy, was unrevealing. She had no history of nephrolithiasis or recurrent urinary tract infections.
Her renal course was notable for two episodes of acute kidney injury, with a baseline creatinine of approximately 0.9 mg/dL and a peak creatinine of 1.26 mg/dL, stabilizing around 0.9–1.1 mg/dL. Serial urinalyses demonstrated persistent microscopic hematuria (3+ blood, RBCs too numerous to count) with minimal proteinuria (urine protein-creatinine ratio ~0.1 mg/mg).
Serologic evaluation revealed ANA 1:160, normal complement levels, negative dsDNA, negative viral serologies, and mildly elevated serum free light chain ratio (K/L ~1.9). Given sicca symptoms and positive ANA, she underwent rheumatologic evaluation including salivary gland biopsy, which was negative for Sjögren’s syndrome. Hematologic evaluation demonstrated no evidence of plasma cell dyscrasia or occult malignancy.
Kidney biopsy revealed DNAJB9-positive fibrillary glomerulonephritis with mesangial expansion, focal crescents, focal segmental glomerulosclerosis, 36% global glomerulosclerosis, and mild interstitial fibrosis/tubular atrophy.
Discussion
This case highlights an atypical presentation of FGN with isolated microscopic hematuria and minimal proteinuria. Kidney biopsy should be considered in patients with persistent unexplained hematuria, particularly when accompanied by subtle renal dysfunction. This presentation expands the recognized clinical spectrum of FGN and raises important questions regarding its natural history and optimal management in indolent and idiopathic cases.