Kidney Week

Abstract: FR-PO0711

Partial Remission of Phospholipase A2 Receptor (PLA2R) Antibody-Positive Membranous Nephropathy Refractory to Rituximab with Use of Obinutuzumab

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

• Lopez-Gutierrez, Pedro A., The University of New Mexico Department of Internal Medicine, Albuquerque, New Mexico, United States

Pedro A. Lopez-Gutierrez, MD

• Saeed, Wajeeha, The University of New Mexico Department of Internal Medicine, Albuquerque, New Mexico, United States

Wajeeha Saeed, MD, MPH

• Aguilar, Sandy F., The University of New Mexico Department of Internal Medicine, Albuquerque, New Mexico, United States

Sandy F. Aguilar, MD, MSc

• Abdali, Mohamed, The University of New Mexico Department of Internal Medicine, Albuquerque, New Mexico, United States

Mohamed Abdali, MD

• Garcia, Pablo, The University of New Mexico Department of Internal Medicine, Albuquerque, New Mexico, United States

Pablo Garcia, MD, MS, FASN

Introduction

Primary membranous nephropathy (PMN) is commonly associated with anti-PLA2R antibodies and often responds to rituximab. However, management of rituximab-refractory disease remains challenging, with limited evidence supporting alternative therapies. We report successful treatment with obinutuzumab in a young patient with refractory PLA2R-positive PMN.

Case Description

A 24-year-old woman was referred to our nephrology service 8 months after diagnosis of PLA2R-positive membranous nephropathy without fibrosis on kidney biopsy. She had received two rituximab infusions without clinical or serologic response. At presentation to our clinic, serum albumin was 1.5 g/dL with nephrotic-range proteinuria and progressive lower-extremity edema. PLA2R antibody titer was 1:160.

Treatment options were discussed, including calcineurin inhibitors, repeat rituximab, the Ponticelli regimen, and obinutuzumab. Cyclosporine was started at 100 mg twice daily, but was reduced to 75 mg twice daily due to worsening hypertension requiring escalation of antihypertensive therapy. Despite this, serum albumin continued to decline to 1.1 g/dL with persistent nephrotic syndrome and edema.


Because of inadequate response and cyclosporine-associated adverse effects, obinutuzumab was initiated after negative latent tuberculosis screening. The patient received obinutuzumab 1 g in two doses. After this PLA2R antibodies became undetectable with marked improvement in edema and rising serum albumin. Albumin improved to 3.3 g/dL by February 2026. Urine protein to creatinine ratio in 24 hrs decreased from 6.5 to 2.85. CD19 count remained suppressed throughout the whole course.

Discussion

This case highlights obinutuzumab as a potential salvage therapy for rituximab-refractory PLA2R-positive PMN and supports emerging evidence for alternative anti-CD20 therapies in resistant disease.