Abstract: FR-PO0689
Neurorenal Autoimmunity Unveiled: Atypical Guillain-Barre Syndrome with Concurrent NELL-1-Positive Membranous Nephropathy
Session Information
- Glomerular Diseases: Membranous Nephropathy, FSGS, and Podocytopathies
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
- Kalfayan, Garo Christopher, Olive View UCLA Medical Center, Sylmar, California, United States
- Kamarzarian, Anita, Olive View UCLA Medical Center, Sylmar, California, United States
- Oldford, Elaine J., University of California Los Angeles, Los Angeles, California, United States
- Jafari, Golriz, Olive View UCLA Medical Center, Sylmar, California, United States
- Pham, Phuong-Chi T., Olive View UCLA Medical Center, Sylmar, California, United States
- Lin, Mercury Y., Cedars-Sinai Medical Center, Los Angeles, California, United States
Introduction
Neural epidermal growth factor like 1 (NELL-1) is a secreted protein predominantly in neural tissues with limited renal expression. It's a target antigen in membranous nephropathy (MN), particularly in PLA2R negative cases, that may have a role in neurologic autoimmunity. We report a case of atypical Guillain Barre syndrome (GBS) presenting concurrently with NELL-1 associated MN, suggesting a shared immunopathogenic mechanism.
Case Description
A 58-year-old man presented with bilateral facial weakness and found to have nephrotic syndrome, spot urine protein to creatinine ratio 14.18 g/g, serum creatinine 0.67 mg/dL. Lumbar puncture did not show albuminocytologic dissociation, atypical GBS was diagnosed. Kidney biopsy revealed MN with positive staining for NELL-1 and negative staining for PLA2R. The patient was treated with intravenous immunoglobulin (IVIG), resulting in significant neurologic improvement. Proteinuria also improved without MN specific therapy, UPC drop to 3.3 g/g at one month.
Discussion
The coexistence of GBS and NELL-1 positive MN is rare. Emerging literature suggests NELL-1 may function as a shared autoantigen, contributing to concurrent injury, supporting a unified immune mediated process. The temporal association and parallel improvement following IVIG in this case may support this hypothesis as well.
Management requires a multidisciplinary approach and should be individualized based on clinical response. In our patient, improvement in both neurologic symptoms and proteinuria following IVIG alone suggests that initial therapy targeting the neurologic process may be sufficient. However, in patients with persistent nephrotic syndrome or relapse, escalation to systemic immunosuppression, including B cell directed therapy such as rituximab or cytotoxic therapy with cyclophosphamide is warranted. Treatment decisions will depend on neurologic severity, renal findings, and overall disease trajectory.
Nell-1 Staining of a Membranous Glomerulus