Primary Membranous Nephropathy (PMN)

Kidney

Overview
Symptoms
Complications
Research
Resources
Stories & Profiles

Overview

Primary membranous nephropathy (PMN) is a rare autoimmune disease. It happens when part of the immune system, called the complement system, mistakenly attacks the kidney filters. These filters help clean the blood, so when they are damaged, the kidneys cannot work as well.

When the kidneys are not filtering properly, protein can leak into the urine. This is called proteinuria. People with PMN may notice foamy urine, swelling in the legs or around the eyes, tiredness, or side effects from medicines that lower the immune system.

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At A Glance

Kidney condition Autoimmune condition Rare condition

Types of Primary Membranous Nephropathy (PMN)

PMN(Primary Membranous Nephropathy)Primary membranous nephropathy happens when the immune system mistakenly attacks the kidney filters. This is the most common type and is usually linked to antibodies such as anti-PLA2R.
Secondary Membranous NephropathySecondary membranous nephropathy is caused by another underlying condition, such as lupus, infections, certain cancers, or some medicines.

Diagnosis Journey

Understanding SymptomsMany people first notice signs like foamy urine, swelling in the legs or around the eyes, or feeling more tired than usual. These symptoms can be easy to miss, so it is common for PMN to go undiagnosed at first.Seeing a Healthcare ProviderA doctor may order tests if they see protein in the urine or changes in kidney function. This often starts with simple blood and urine tests.Blood TestsBlood tests can help measure kidney function and look for antibodies linked to PMN, such as anti-PLA2R.Urine TestsUrine samples show how much protein is leaking into the urine. This helps doctors understand how the kidneys are working.Kidney BiopsyIn many cases, a kidney biopsy is used to confirm the diagnosis. A small sample of kidney tissue is looked at under a microscope to check for the changes seen in PMN.Monitoring Over TimeOnce diagnosed, people with PMN are followed with regular blood and urine tests to watch protein levels, kidney function, and symptoms.

Treatment Options

01Blood Pressure MedicationsMedicines like ACE inhibitors or ARBs can help lower protein in the urine and reduce stress on the kidneys.
02DiureticsThese “water pills” help the body get rid of extra fluid and can reduce swelling in the legs, feet, and around the eyes.
03StatinsSome people with PMN develop high cholesterol, and statins can help manage those levels.
04Immune-Modifying TreatmentsMedications such as rituximab or other immune-suppressing drugs are sometimes used to lower the immune system’s attack on the kidneys.
05Diet and Lifestyle ChangesLimiting salt, eating a balanced diet, staying active, and managing blood pressure can support kidney health.
06Monitoring and Regular TestingMany people with PMN are closely followed by their doctors with blood and urine tests to track kidney function and protein levels.

Complications

Ongoing Protein Loss: High levels of protein in the urine can weaken the body and lead to long-term kidney strain.

Fluid Retention and Swelling: As kidney function changes, the body may hold on to extra fluid, causing swelling in the legs, feet, or around the eyes.

High Blood Pressure: Kidney damage can make it harder for the body to control blood pressure, which can worsen kidney function over time.

High Cholesterol Levels: Protein loss can cause the liver to make more cholesterol, which may increase heart-related risks.

Risk of Blood Clots: People with PMN may be at higher risk of developing blood clots due to changes in protein levels.

Progression to Kidney Damage: If PMN continues to worsen, the kidneys may lose their ability to filter blood well. In some cases, this can lead to chronic kidney disease or, rarely, kidney failure.

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Ongoing Research

Discover our featured studies below for PMN. If these studies are not right for you, there are over 53 studies actively recruiting patients with PMN. Visit ClinicalTrials.gov to find a study near you.

Research & Resources

Clinical research helps scientists learn more about Primary Membranous Nephropathy (PMN) and develop better treatments for the future.

FEATURED CLINICAL STUDY

AUTUMN Clinical Study

A clinical study for adults with primary membranous nephropathy to understand how a study drug reduces symptoms and helps preserve kidney function.

Recruiting

View Study

Related Stories & Profiles

Explore relevant human stories and expert perspectives connected to this condition.

Patient Story

Patience, Protein, and a Pretty Good Life: Mallory’s story of living with membranous nephropathy

Mallory was sixteen when COVID quietly went after her kidneys. Here's how she made it from the cancer floor of a children's hospital to college, travel plans, and a pretty good life. One Mrs. Dash shaker at a time.

Read Story

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Investigator Profile

Dr. Sayna Norouzi

Director of the Glomerular Disease Clinic and the Polycystic Kidney Disease Clinic

Loma Linda University

Dr. Sayna Norouzi, MD, FASN, is an associate professor of medicine and clinical nephrologist at Loma Linda University Medical Center, where she is the founder and director of the Glomerular Diseases Clinics. She also serves as co-director of the online GlomCon Glomerular Diseases Fellowship Program and is a member of the Alpha Omega Alpha Honor Medical Society. Dr. Norouzi completed her nephrology fellowship at Baylor College of Medicine and serves as principal investigator on multiple clinical trials focused on glomerular and rare kidney diseases.

View Profile

Dr. Arun Rajasekaran on Glomerular Disease: Clinical Trials and Patient Care

Investigator Profile

Dr. Arun Rajasekaran, MD, FACP, FASN, FNKF

Co-Director, Glomerular Disease Center and Clinical Trials Unit, Renal Medicine Associates

Glomerular Disease Center

Dr. Arun Rajasekaran, MD, FACP, FASN, FNKF, is a nephrologist and clinical trial investigator specializing in glomerular diseases. He earned his medical degree at Kasturba Medical College in Manipal, India, completed his internal medicine residency at the University of Central Florida College of Medicine in Orlando, and went on to a nephrology fellowship and an advanced clinical and research fellowship in glomerular diseases at the University of Alabama at Birmingham (UAB), where he later served on the faculty and the core glomerular disease clinic team. He is board certified in internal medicine and nephrology. Today he is co-director of the Glomerular Disease Center and Clinical Trials Unit at Renal Medicine Associates in Albuquerque, New Mexico, and an assistant professor at the Burrell College of Osteopathic Medicine. He is a core faculty member of the GlomCon Foundation and is a progam director at the GlomCon Foundation's glomerular disease virtual fellowship. He is a board member of the New Mexico Kidney Foundation. His research interests include IgA nephropathy, membranous nephropathy, and lupus nephritis.