Abstract: PUB187
Fibrillary Glomerulonephritis in a Patient with Long-Standing Hypertension, Proteinuria, and Advanced CKD: Not Everything Is Hypertension
Session Information
Category: Trainee Case Report
- 1201 Glomerular Diseases: Fibrosis and Extracellular Matrix
Authors
- Samiratedu, Michael M., University of Miami School of Medicine, Miami, Florida, United States
- Shahoori, Neda, University of Miami School of Medicine, Miami, Florida, United States
- Zuo, Yiqin, University of Miami School of Medicine, Miami, Florida, United States
- Munoz Mendoza, Jair, University of Miami School of Medicine, Miami, Florida, United States
Introduction
Fibrillary glomerulonephritis (FGN) is a rare glomerular disease that mostly affects patients in their fifth or sixth decade of life. Clinical manifestations include elevated creatinine, hypertension (HTN), hematuria, and proteinuria. FGN has been associated with monoclonal gammopathy, autoimmune diseases and viral infections. However, many of the cases ultimately have no precipitating factor identified.
Case Description
We present a case of a 65 years-old man with history of diabetes mellitus for 6 years without retinopathy, HTN and chronic kidney disease (CKD) who presented to our hospital with acute kidney injury after increasing dose of lisinopril for uncontrolled hypertension. Physical exam was unremarkable except for high BP 154/85 mmHg, and mild lower extremity edema. Laboratory studies revealed a serum creatinine of 4.13mg/dL (baseline 2.9 mg/dL, eGFR 22 ml/min/m2), UPCR of 7.1 g/d, UA showed 10 RBCs and 3+ protein. No RBC on repeat UA. He was negative for Hepatitis B, C, and ANCA, anti-GBM, ANA, and anti-dsDNA Ab. C3,C4 were normal, SPEP showed no M spike, and elevated kappa/lambda ratio of 1.81 (89.7 / 49.6 mg/L). Renal biopsy revealed 20-30% interstitial fibrosis, diffuse, moderate to severe mesangial expansion by eosinophilic deposits with segmental mild increase in mesangial cellularity, polyclonal IgG-dominant smudgy mesangial staining with capillary loop extension with kappa/lambda light chain shift, and mesangial and subendothelial deposits with non-branching randomly arranged fibrils (7-21 nm). A Congo red stain was negative for amyloidosis. Immunohistochemical staining for DNAJB9 was positive, supporting the diagnosis of FGN.
Discussion
This case highlights the importance of pursuing a kidney biopsy in patients with worsening proteinuria and kidney function even without active sediment and negative work up for GN. In patients with long standing history of HTN, it is not uncommon to blame HTN as the cause of the CKD. However, diseases such as FGN although rare should always be considered as part of our differential diagnosis. Whether we should treat with immunosuppression or continue conservative management in this patient with advanced chronic kidney disease is debatable but knowing the diagnosis of FGN will certainly help to establish a better prognosis.