Abstract: TH-PO687
Ureteral Obstruction as a Risk Factor for Anti-Glomerular Basement Membrane (GBM) Disease
Session Information
- Glomerular Diseases: Epidemiology and Case Reports
November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Dunleavy, Megan, Cooper University Health Care, Camden, New Jersey, United States
- Kudose, Satoru, Columbia University, New York, New York, United States
- Dawson, Solomon, Cooper University Health Care, Camden, New Jersey, United States
- Srinivasan, Vinay, Cooper University Health Care, Camden, New Jersey, United States
Introduction
Anti-glomerular basement membrane (anti-GBM) disease has an incidence of 0.5–1 per million population; possible triggering factors including smoking & hydrocarbon exposure. Limited data also suggests a link between obstructive uropathy & the development of anti-GBM antibodies. We present a case of a 77-year-old male with chronic bilateral hydroureteronephrosis who subsequently developed anti-GBM disease & was successfully treated with a combination of steroids, cyclophosphamide, & plasmapheresis.
Case Description
A 77-year-old male with history of Chronic Kidney Disease Stage 3a presented for a routine outpatient evaluation; he was asymptomatic at time of presentation. Laboratory evaluation was notable for a serum creatinine of 4.42 mg/dL that had increased from 1.31 mg/dL seven months earlier. Urine microscopy showed numerous dysmorphic RBCs/HPF raising concern for a rapidly progressive glomerulonephritis (RPGN) prompting inpatient admission. CT imaging studies were notable for chronic bilateral hydroureteronephrosis dating back for at least two years. His serologic evaluation was negative with the exception of anti-GBM antibody that was positive at 1.8 U.
Repeat imaging showed continued bilateral hydronephrosis initially delaying kidney biopsy however NM MAG3 scan did not reveal a high-grade urodynamic obstruction. After urologic evaluation, the patient underwent a native kidney biopsy confirming anti-GBM disease. He received pulse dose steroids, followed by cyclophosphamide, Prednisone taper, & 14 sessions of plasmapheresis. His serum creatinine has nadired at 2.6 mg/dL & anti-GBM antibodies are now undetectable.
Discussion
Anti-GBM antibodies target a cryptic α3 antigen of the non-collagenous 1 domain of type IV collagen. It is hypothesized that disruption of this domain, exposing the α-3 chain, is required for anti-GBM antibodies to develop. While several environmental triggers have been implicated in this process, ureteral obstruction & hydronephrosis remain an under-recognized & poorly understood trigger. Although challenging due to the rare nature of this disease process, further studies are needed to elucidate the nature of this relationship.