Kidney Week

Abstract: PUB349

NELL-1-Positive Membranous Nephropathy

Session Information

• Publication Only

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Valdesuso, Alejandro, Landmark Medical Center, Woonsocket, Rhode Island, United States

Alejandro Valdesuso, MD

• Mansoor, Sobia, Landmark Medical Center, Woonsocket, Rhode Island, United States

Sobia Mansoor, MD, MBBS

• Kudose, Satoru, Columbia University, New York, New York, United States

Satoru Kudose, MD

• Kruger Gomes, Larissa, Landmark Medical Center, Woonsocket, Rhode Island, United States

Larissa Kruger Gomes, MD

Introduction

Membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults with over 20 novel target antigens discovered. NELL-1 is the second most common after PLA2R.

Case Description

57-year-old male with PMHx of HTN and obesity was referred to the nephrology clinic for proteinuria. Patient was well until 3 months prior when he presented to the ED with lower extremity edema and shortness of breath and was diagnosed with a right lower extremity DVT and PE. BMP showed normal serum creatine. He was started on Eliquis. Persistent lower extremity edema led to a 24-hour urine protein test which showed 12 g of protein. A previous UA 7 months earlier showed no proteinuria. Nephrological work up was negative for glomerular basement membrane, c-ANCA, p-ANCA and PLA2R antibodies, with normal C3 and C4 levels. Kidney biopsy revealed segmental membranous nephropathy, mild tubular atrophy and interstitial fibrosis, severe arteriosclerosis and mild arteriolosclerosis. Immunohistochemical staining for NELL-1 was positive. Patient’s lisinopril was increased to highest tolerated dose, and vitamin supplements he was taking were stopped. However, high-grade proteinuria persisted prompting the initiation of rituximab.

Discussion

NELL-1 MN, while mostly seen in adults like PLA2R MN, typically has a higher age of onset. Mercury-containing indigenous remedies and lipoic acid supplements have been associated with NELL-1 MN, with discontinuation resulting in remission. Unfortunately, the patient’s supplements did not contain these agents. Compared to PLA2R MN, NELL-1 MN has a more robust association with malignancy with as many as 10-33% of cases. In the case, age-appropriate cancer screening as well as PAN CT scan was done; however, no malignancy was found. Still, close follow up is recommended. Finally, NELL-1 MN is more resistant to treatment and more likely to recur. Patient’s proteinuria has decreased to 2.7 mg/mg after two sessions of rituximab, but he has not achieved remission yet.