Abstract: SA-PO0779
Concurrent Phospholipase A2 Receptor (PLA2R) Antibody-Positive Membranous Nephropathy and Lupus Nephritis: A Case of Dual Glomerular Disease
Session Information
- Glomerular Diseases: Lupus Nephritis, Monoclonal Gammopathy-Related Disease, and Transplantation
October 24, 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
- Naqvi, Zehra Fatima, Houston Methodist The Woodlands, Conroe, Texas, United States
- Patel, Amol M., Houston Methodist The Woodlands, Conroe, Texas, United States
- Naqvi, Sheherbano Fatima, The University of Texas at Austin, Austin, Texas, United States
Group or Team Name
- Houston Methodist The Woodlands
Introduction
Membranous nephropathy is a leading cause of nephrotic syndrome in nondiabetic adults with treatment and prognosis dependent on underlying etiology. Historically, the anti-PLA2R antibody has been documented almost 100% specific for diagnosing primary membranous nephropathy. This is a case of PLA2R positive membranous nephropathy with shared features of lupus nephritis. We will discuss the diagnostic and treatment dilemma in hopes to further study the relationship of these two autoimmune conditions.
Case Description
A 52 year old female with rheumatoid arthritis, SLE, resistant hypertension was experiencing progressive weakness, joint pain, and bilateral leg swelling for several weeks. Serology showed Cr 0.9, BUN 28, homogenous ANA 1:320, dsDNA 21, rheumatoid factor 201, and negative C3 and C4. Additionally, she had a urine protein:creatinine of 5.8 g/g without hematuria or pyuria. She was on hydroxychloroquine and leflunomide for rheumatoid arthritis and was referred for nephrology evaluation due to nephrotic range proteinuria. Additional tests revealed an anti-PLAR2 ab titer of 107 RU/ml. Kidney biopsy showed “spikes” along the glomerular basement membrane without intra or extracapillary cell proliferation. Immunofluorescence showed positive full house staining of IgG, IgA, IgM, C3, C4, and C1q. Electron microscopy showed numerous dense immune complex membranous deposits without subendothelial deposits. She was evaluated to have anti-PLA2R membranous nephropathy with features of class IV lupus nephritis. Due to severe symptoms and degree of anti-PLA2R titer, she was treated with IV rituximab and started on mycophenolate mofetil for SLE. Over six months, her clinical condition improved. Anti-PLA2R ab antibodies resulted undetectable, and urine protein:creatinine decreased to 0.5 g/g.
Discussion
While it is known that anti-PLA2R ab can have low-titer positivity in SLE, this is the first case of SLE to our knowledge with a significantly high titer and concomitant membranous nephropathy. This raises a diagnostic and treatment dilemma. Ultimately the patient was treated with IV rituximab and mycophenolate mofetil with subsequent resolution of anti-PLA2R ab levels and significant clinical improvement. This case sheds light on theories of epitope spreading that may underlie autoimmune processes driving B cell dysregulation in these two autoimmune conditions.