Kidney Week

Abstract: TH-PO1099

Phospholipase A2 Receptor (PLA2R) Antibody-Negative Membranous Nephropathy with IgG Lambda Light Chain-Restricted Deposits Presenting as Nephrotic Syndrome in a Young Woman

Session Information

• Pathology and Lab Medicine
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pathology and Lab Medicine

• 1700 Pathology and Lab Medicine

Authors

• Nenwani, Hari Vishal, SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Hari Vishal Nenwani, MBBS

• Suraj, Fnu, SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Fnu Suraj, MBBS

• Syed, Jahanghir, SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Jahanghir Syed, MD

• Safi, Adnan, SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Adnan Safi, MBBS

• Akatibo, Emmanuel, SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Emmanuel Akatibo, MBChB

• Kouyate, Gnama, SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Gnama Kouyate, MD

• Puri, Isha, SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Isha Puri, MD

• Mohamed, Ibrahim A., SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Ibrahim A. Mohamed, MD

• Azhar, Muhammad, SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Muhammad Azhar, MD

• Mallappallil, Mary C., SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Mary C. Mallappallil, MD, FASN

• Salifu, Moro O., SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Moro O. Salifu, MD, MBA, MPH

• Saggi, Subodh J., SUNY Downstate Health Sciences University College of Medicine, New York, New York, United States

Subodh J. Saggi, MD, MPH

Introduction

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults. Most cases are primary and PLA2R-associated. Light chain–restricted IgG deposits in an MN pattern are rare and raise concern for monoclonal gammopathy of renal significance (MGRS), even in the absence of detectable circulating monoclonal protein.

Case Description

A previously healthy 27-year-old woman presented with nephrotic syndrome and acute kidney dysfunction (UPCR 8,574 mg/g, albumin 2.3 g/dL, creatinine peak 3.7 mg/dL). and serum albumin 2.3 g/dL, hyperlipidemia. Serum creatinine of 2.2 mg/dL, peaking at 3.7 mg/dL during the hospital course. Kidney biopsy showed stage III PLA2R-negative membranous nephropathy with IgG lambda light chain–restricted subepithelial deposits and moderate interstitial fibrosis. Serologic and hematologic evaluation, including SPEP, immunofixation, free light chain ratio, and flow cytometry, showed no evidence of systemic monoclonal gammopathy or clonal lymphoproliferative disorder.

Discussion

Light chain restriction in membranous nephropathy (MN) is uncommon and raises suspicion for MGRS or occult lymphoproliferative disease, especially in PLA2R-negative cases. However, circulating monoclonal protein may be absent in many monoclonal immunoglobulin–associated glomerulopathies, making diagnosis challenging. We describe a rare case of PLA2R-negative MN with IgG lambda light chain–restricted deposits in a young woman with nephrotic syndrome and progressive kidney dysfunction but no detectable systemic monoclonal gammopathy. Her young age and negative hematologic evaluation further complicated classification, highlighting the importance of a multidisciplinary evaluation for occult MGRS despite negative conventional studies.