Kidney Week

Abstract: TH-PO678

Double Trouble in the Basement! A Case of Phospholipase A2 Receptor (PLA2R)-Associated Membranous Nephropathy with Atypical Anti-glomerular Basement Membrane Disease

Session Information

• Glomerular Diseases: Case Reports - 1
  October 24, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Tolani, Renuka, Houston Methodist, Houston, Texas, United States

Renuka Tolani, DO

• Thurston, Theresa, Texas A&M University System, College Station, Texas, United States

Theresa Thurston

• Sathiyaraj, Steffi, Houston Methodist, Houston, Texas, United States

Steffi Sathiyaraj, MD

• Lyu, David, Houston Methodist, Houston, Texas, United States

David Lyu, MD

• El-Zaatari, Ziad M., Houston Methodist, Houston, Texas, United States

Ziad M. El-Zaatari

• Truong, Luan D., Houston Methodist, Houston, Texas, United States

Luan D. Truong, MD

• Edwards, Angelina, Houston Methodist, Houston, Texas, United States

Angelina Edwards, MD, FASN

• Shafi, Tariq, Houston Methodist, Houston, Texas, United States

Tariq Shafi, MBBS, MHS, FASN

• Bobart, Shane A., Houston Methodist, Houston, Texas, United States

Shane A. Bobart, MD, FASN

Introduction

Only a few cases have been reported of concurrent atypical anti-glomerular basement membrane (anti-GBM) disease with membranous nephropathy. Compared to typical anti GBM disease, atypical anti GBM disease is often seronegative, with a mild disease presentation and course. We present a case of concomitant of PLA2R associated membranous nephropathy and atypical anti-GBM disease in a patient with cholangiocarcinoma.

Case Description

A 66-year-old male with type 2 diabetes, hypertension, hyperlipidemia, viral hepatitis C, cirrhosis, and cholangiocarcinoma presented with nephrotic range proteinuria, and worsening bilateral lower extremity edema. Urine studies showed 3+ protein and 13 red blood cells per high powered field and 24-hour urine proteinuria of 14 grams with serum albumin of 2.1 g/dL, and serum creatinine 0.8 mg/dL. (nephrotic syndrome). Serological work-up was negative for ANA, anti-dsDNA, PLA2R, ANCA, rheumatoid factor, and anti-GBM, with normal complements, and no monoclonal gammopathy. A kidney biopsy showed membranous nephropathy with typical light microscopic, immunofluorescent, and electron microscopic changes. In addition, there was atypical anti-GBM disease characterized by a non-circumferential cellular crescent in 1 out of 12 glomeruli, and 2-3+ linear staining for IgG along glomerular basement membrane with 2+ C3, kappa and lambda light chain. There was no tubular basement membrane staining for IgG. The glomeruli demonstrated strong staining for PLA2R, but negative for THSD7A and NELL-1. The patient received rituximab infusion, dapagliflozin, and lisinopril, resulting in remission of proteinuria. Despite intense chemotherapy with cisplatin, gemcitabine and immunotherapy, the malignancy progressed, and he transitioned to hospice care.

Discussion

For our patient, rituximab resulted in remission of proteinuria, but malignancy had progressed. The lack of temporal association is consistent with the biopsy findings of PLA2R -associated membranous nephropathy. While there is not an established guideline, our case demonstrates the utility of rituximab for the management of concurrent atypical anti-GBM disease with membranous nephropathy.