Abstract: PUB591
Fibrillary Glomerulonephritis Presenting as Hematuria
Session Information
Category: Trainee Case Report
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Han, Hwarang Stephen, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
- Tahir, Imran, Northeastern Health System, Tahlequah, Oklahoma, United States
Introduction
Fibrillary glomerulonephritis (FGN) is a glomerular disease with pathognomonic findings seen on EM revealing randomly arranged nonamyloid fibrillary deposits that are 10 to 30nm. The disorder is found only in <1% of native kidney biopsies. Most patients present with nephrotic range proteinuria, hematuria and reduced renal function. We report a case of a patient with hematuria with normal renal function who was found to have FGN.
Case Description
A 51-year-old female came to clinic for evaluation of hematuria which was present for the past year. Urinalysis showed trace amount of protein and 3+ blood with RBC count of 5-15 per high power field. Protein to creatinine ratio was 0.6 mg/mg. Creatinine of 1.0 mg/dL and Hgb was 16.6 g/dL. CT showed no signs of nephrolithiasis. Urology performed cystoscopy with unremarkable findings.
Renal biopsy revealed mesangial expansion, congo red negative, DNAJB9 immunohistochemistry positive in glomeruli, and electron microscopy showed mesangial areas and segmental regions of the capillary loops with deposition of randomly oriented non-branching fibrils that were mostly 20nm, warranting a diagnosis of FGN. Secondary workups were negative. Patient continues to have hematuria after 1 year of follow up but renal function remained stable with lisinopril 20mg daily.
Discussion
Fibrillary deposit glomerular diseases are divided into 3 main categories: amyloidosis, immunotactoid glomerulopathy, and FGN. Amyloid is congo red positive with fibrillary deposits that are about 10nm. Immunotactoid glomerulopathy is congo red negative and fibrils deposits are 30 to 50nm. FGN is congo red negative with fibril deposits of about 20nm. New markers such as DNAJB9 has shown to identify FGN without the need of EM. Serum level of DNAJB9 has also been shown to predict diagnosis of FGN. This case is unique since patient did not have the classic signs of FGN. Currently there are no optimal treatments for idiopathic FGN and high as 40-50% of patients develop ESRD.
DNAJB9 immunohistochemistry