Abstract: FR-PO733
B-Cell Lymphoproliferative Disorder With NELL-1 Membranous Nephropathy
Session Information
- Glomerular Diseases: Podocyte Biology - I
November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1304 Glomerular Diseases: Podocyte Biology
Authors
- Patel, Neha, TriHealth, Cincinnati, Ohio, United States
- Mccann, Timothy P., TriHealth, Cincinnati, Ohio, United States
- Rajput, Amit K., TriHealth, Cincinnati, Ohio, United States
Introduction
The predominant target antigen for primary membranous nephropathy (MN) has been Phospholipase A2 receptor (PLA2R), present in approximately 70% of cases. Neural epidermal growth factor like 1 protein (NELL-1) was recently identified as a new antigen in a distinct type of primary MN. NELL-1 was found to be the first candidate antigen highly prevalent in malignancy associated MN, seen in 33% of all cases. We will review a case of NELL-1 membranous nephropathy.
Case Description
A 54-year-old Caucasian female presented with shortness of breath, left flank/lower back pain, and bilateral lower extremity edema for four days. Physical exam exhibited BP 170/99 mmHg, nontender cervical lymphadenopathy (LAD), left CVA tenderness, and 2+ pitting edema. Initial labs were significant for elevated D-dimer, hypoalbuminemia (Alb 1.7g/dL), and nephrotic range proteinuria (UPCR 13.5g). Imaging revealed bilateral subsegmental pulmonary emboli, left renal vein thrombosis, and extensive bilateral LAD (axillary, supraclavicular, mediastinal, left periaortic retroperitoneal). Given concerns for podocytopathy due to a possible lymphoma, the patient underwent an unremarkable extensive serologic workup. Renal biopsy revealed NELL-1 MN, with diffuse (3+) fine granular staining along glomerular capillary loops for NELL-1 and subepithelial deposits with severe foot process effacement.
Bone marrow biopsy, excisional axillary/cervical lymph node biopsies, PET scan, infectious workup, and age-appropriate malignancy screenings were nondiagnostic. Biopsies showed reactive lymphadenopathy concerning for evolving B-cell lymphoproliferative disorder with plasmacytic differentiation. Given the biopsy findings and NELL-1 MN, she was treated with rituximab. However, significant proteinuria persisted despite treatment. The patient refused cyclophosphamide and unfortunately, developed additional complications including a transient ischemic attack.
Discussion
NELL-1 is a rare emerging subtype of MN that has been identified in both primary MN and malignancy associated nephropathy. A thorough malignancy workup is warranted in all patients diagnosed with NELL-1 MN. More research is needed in the association between NELL-1 and specific cancers, in hopes of guiding future treatments for this disease.