Kidney Week

Abstract: PUB143

Primary Fibrillary Glomerulonephritis in an Older Patient with Immunosuppression Challenges

Session Information

• Publication Only

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Raza, Muhammad, PennState S. Milton Hershey Medical Center, York, Pennsylvania, United States

Muhammad Raza, MD

• Tahir, Maria, PennState S. Milton Hershey Medical Center, York, Pennsylvania, United States

Maria Tahir, MD

• Siddiqi, Mahwash, PennState S. Milton Hershey Medical Center, York, Pennsylvania, United States

Mahwash Siddiqi, MD

• Portela-Colon, Rafael, PennState S. Milton Hershey Medical Center, York, Pennsylvania, United States

Rafael Portela-Colon, MD, FASN

Introduction

Fibrillary glomerulonephritis (FGN) is an uncommon glomerular disorder characterized by randomly oriented, non-amyloid fibrils and strongly associated with DNAJB9 immunoreactivity. In the absence of randomized controlled trials, management is guided by observational data and expert consensus. Therapeutic decisions depend on whether FGN is primary or secondary to conditions such as paraproteinemia, autoimmune disease, malignancy, or chronic infection. Primary FGN has demonstrated variable responsiveness to immunosuppression, including rituximab, in several case series, but treatment in older adults is complicated by infection risk and comorbidities.

Case Description

A 75-year-old woman presented with a one-year history of progressive renal dysfunction and new lower-extremity edema. Evaluation revealed nephrotic-range proteinuria. Kidney biopsy demonstrated FGN with moderate interstitial fibrosis and tubular atrophy, absence of crescents, and positive DNAJB9 staining, confirming the diagnosis. She was initiated on high-dose corticosteroids, RAAS blockade, and SGLT2 inhibition, with plans to begin rituximab. Shortly after diagnosis, she developed COVID-19 pneumonia with bacterial superinfection requiring hospitalization. Rituximab was deferred, and corticosteroids were continued. Renal function stabilized transiently but did not improve. Months later, she presented with uremic symptoms necessitating hemodialysis. Rituximab was again considered; however, she developed disseminated varicella infection, prompting a steroid taper and avoidance of further immunosuppression. She subsequently progressed to ESRD.

Discussion

This case underscores the therapeutic complexity of managing primary FGN in elderly, infection-prone patients. Although immunosuppression may slow disease progression, recurrent severe infections may preclude its use, limiting potential renal recovery. DNAJB9 staining provided diagnostic certainty, but frailty, infectious complications, and limited therapeutic windows constrained management. This case highlights the need for individualized risk–benefit assessment and the development of safer, targeted therapies for older adults with primary FGN.