Chronic kidney disease (CKD) often develops from conditions like diabetes and high blood pressure. In rare instances, however, CKD can also develop from a disease called membranous nephropathy (MN). Learn more about MN here including causes, symptoms, and where to get more support. 

What is membranous nephropathy?

A form of glomerular disease—a disease that affects your glomeruli, the tiny filters in your kidneys—MN occurs as a thickening of the kidney’s filtration system, resulting in kidney damage, and large amounts of protein being lost in your urine. MN is also an autoimmune disease, meaning that it is your own immune system that is attacking your glomeruli, causing changes in them that could lead, eventually, to kidney failure. 

What causes membranous nephropathy?

The more common type of MN, known as primary MN, currently has no known cause. Secondary MN occurs less frequently but is better understood. Secondary MN is most often caused by:

• An infection, 
• A medication, such as a non-steroidal anti-inflammatory drug (NSAID), or 
• An underlying disease such as: 
  • Lupus,
  • Cancer, or
  • Hepatitis B virus.

What are some signs and symptoms of MN? 

MN develops slowly, and many patients do not experience any symptoms for years. If signs or symptoms do become present, they may include:

• Edema, or swelling, in your legs, ankles, and face, especially around your eyes
• Weight gain
• Fatigue
• Foamy urine caused by high protein levels
• High cholesterol (fat levels in the blood)
• Low levels of protein in the blood 

How is membranous nephropathy diagnosed?

As with many rare diseases, getting a diagnosis requires providing the right information to the right professional. Making sense of symptoms and specialized tests can be challenging, especially for medical professionals in general practice. Prior to a diagnosis, some tests you can expect to have done are:

• Urine test to find protein and/or blood in the urine
• Blood test to evaluate protein, estimated glomerular filtration rate (remaining percentage of kidney function), wastes in your blood, and cholesterol
• Kidney biopsy, in which a tiny piece of your kidney is removed, and analyzed under a microscope 

How is membranous nephropathy treated? 

After receiving a diagnosis, your doctor will likely monitor your condition closely for a time without treatment, to see if it will go into remission on its own. They may provide supportive care, however, in the form of drugs to lower blood pressure and/or reduce water retention. A low-sodium diet may also be recommended. 

If your symptoms persist, stronger medicines may be prescribed which may negatively affect your immune system. In some cases, MN leads to kidney failure, where a kidney transplant or dialysis is needed to stay alive. In other cases, treatment prevents kidney function from declining to that degree. 

It’s important to speak with your doctor and ask plenty of questions regarding treatments and the progression of MN. While MN is a serious disease that can not be cured, it can potentially be managed well for a long time. 

*Membranous Nephropathy (MN). (2022, August 29). National Kidney Foundation. https://www.kidney.org/atoz/content/membranous-nephropathy-mn