Kidney Week

Abstract: TH-PO0820

Membranous Nephropathy Diagnosed During Pregnancy: Three Clinical Courses, One Multidisciplinary Strategy

Session Information

• Glomerular Case Reports: Membranous, PGN, GBM, and More
  November 06, 2025 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Porcu, Clara Valentina, IRCCS Azienda Ospedaliero-Universitaria di Bologna Policlinico di Sant'Orsola, Bologna, Emilia-Romagna, Italy

Clara Valentina Porcu

• Fois, Antioco, Centre Hospitalier du Mans, Le Mans, Pays de la Loire, France

Antioco Fois, MD

• Piccoli, Giorgina B., Centre Hospitalier du Mans, Le Mans, Pays de la Loire, France

Giorgina B. Piccoli, MD

• Carta, Simona, Universita degli Studi di Cagliari, Cagliari, Sardinia, Italy

Simona Carta, MD

• Torreggiani, Massimo, Centre Hospitalier du Mans, Le Mans, Pays de la Loire, France

Massimo Torreggiani, MD, PhD

• Mariani, Ilaria, Policlinico Gemelli Unita Operativa Complessa Medicina Interna e Gastroenterologia, Rome, Lazio, Italy

Ilaria Mariani

• Gianferrari, Matteo, Centre Hospitalier du Mans, Le Mans, Pays de la Loire, France

Matteo Gianferrari, MS

Introduction

The presentation of membranous nephropathy (MN) in pregnancy may mimic preeclampsia (PE), leading to diagnostic and treatment delay. Anti-PLA2R serology is a reliable diagnostic tool in MN, particularly useful when a kidney biopsy should preferably be postponed. Therapeutic strategies for MN in pregnancy are also dependent upon gestational week (GW) at diagnosis.

Case Description

Case 1: A 43 year old woman (G3P1) was found with proteinuria (1 g/l) at 20 GW, initially interpreted as pregnancy-related. At 34 GW she was referred to our center, with heavy proteinuria (14 g/24h, serumalbumin 1.4 g/dL) and resulted positive for anti-PLA2R at 35GW. On the account of the late pregnancy term, treatment was postponed and she delivered a healthy male baby (29^th centile) by cesarean section at 37+3 GW. After delivery after q short cycle of Cyclosporine A (CyA) to reduce proteinuria, she received Rituximab (2 cures), attaining stable (3 years) complete remission.
Case 2: A 28 year old woman (G7P5, 1 intrauterine death, 4 PE, 2 terminations) was referred at 12 GW for proteinuria 5.8 g/24h. Anti-PLA2R tested positive (1:200). She was treated with CyA, with rapid partial remission (proteinuria <1 g/l after 4 weeks). She delivered a healthy male baby at 36+1 GW (2.3 centile) because of growth restriction. Post partum, a kidney biopsy showed stage 3 MN. After two cures of rituximab, at 2 years anti-PLA2R are absent and proteinuria is <1g/day.
Case 3: A 27 year old woman (G2P1) was referred at 11 GW with proteinuria 15 g/24h, albumin 1.1 g/dL; anti-PLA2R were negative. A kidney biopsy diagnosed stage 1-2 MN. She was treated with CyA, achieving full remission in 6 weeks. She is now in her 37^th GW, normotensive and without proteinuria.

Discussion

This small series highlights some of the challenges of MN in pregnancy. The fists patient was diagnosed with PE (despite early onset and normal foetal growth), until she was referred in late pregnancy, when we preferred to postpone treatment start (CyA to reduce proteinuria, followed by rituximab). In the 2^nd and 3^rd case, early presentation excluded PE and rapid remission was attained by CyA, allowing postponing rituximab to the post-partum.

Digital Object Identifier (DOI)

• doi: 10.1681/ASN.2025pdjcn8g0