Abstract: FR-PO0800
It's All Linear: A Case of Atypical Anti-Glomerular Basement Membrane Disease
Session Information
- Glomerular Diseases: ANCA Vasculitis, Anti-GBM Disease, and Crescentic GN
October 23, 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
- Chaudhri, Imran, Stony Brook Medicine, Stony Brook, New York, United States
- Hennigar, Randolph Alexander, Stony Brook Medicine, Stony Brook, New York, United States
Introduction
Anti-glomerular basement (GBM) membrane disease is typically characterized by a small vessel vasculitis secondary to antibodies directed at the basement membranes of the glomeruli and alveoli, leading to rapidly progressive glomerulonephritis (RPGN) and alveolar hemorrhage. Diagnosis involves the presence of positive serum anti-GBM antibodies and kidney biopsy showing linear staining of IgG on immunofluorescence. “Atypical” anti-GBM disease is a form of this disease characterized by similar kidney biopsy findings, but with negative serum anti-GBM antibodies. This variant of the disease presents both a diagnostic and therapeutic challenge for nephrologists.
Case Description
A 45 year old man presented to the nephrology clinic due to elevated creatinine. Prior to his nephrology clinic visit, he was admitted to the hospital with abdominal pain and was found to have cholecystitis and possible adenomyomatosis. He underwent cholecystectomy with subsequent improvement in his abdominal pain. During the admission he was noted to have serum creatinine >2 mg/dl, microscopic hematuria, and mild proteinuria. During clinic evaluation, repeat testing showed creatinine >2 mg/dl and ongoing microscopic hematuria. Broad serologic work up was negative including negative serum anti-GBM antibodies. Native kidney biopsy showed diffuse mildly proliferative glomerulonephritis with 3+ linear staining for IgG on immunofluorescence. There was minimal staining for kappa and lambda, so heavy chain disease was considered but remained negative on testing. As renal function was not improving, patient opted for treatment, and he was started on prednisone with slow taper with subsequent improvement in creatinine to 1.5-1.7 mg/dl. Repeat serologic testing has continued to show negative anti-GBM antibodies.
Discussion
This case highlights a presentation of a rare variant of anti-GBM disease, an “atypical” form due to absence of circulating anti-GBM antibodies. Renal function improved after prednisone initiation indicating the role immunosuppression can have in this rare variant. This case emphasizes the importance of native kidney biopsy in making the diagnosis, the role immunosuppresion can play, and a patient centered approach to treatment for this rare condition without readily known management strategies.