What is membranous glomerulonephritis?
Your kidneys are made up of a number of different structures that aid in the removal of wastes from your blood and the formation of urine. Glomerulonephritis (GN) is a condition in which changes in the structures of your kidney can cause swelling and inflammation.
Membranous glomerulonephritis (MGN) is a specific type of GN. MGN develops when inflammation of your kidney structures causes problems with the functioning of your kidney. MGN is known by other names, including extramembranous glomerulonephritis, membranous nephropathy, and nephritis.
Other complications can also arise from this condition, including:
The symptoms of MGN are different for everyone, and you may not have symptoms at all. If symptoms do develop, they typically include:
- swelling of the hands, feet, or face
- foamy urine
- an excessive need to urinate at night
- weight gain
- poor appetite
- blood in the urine
MGN causes damage to your kidney, resulting in the filtration of protein from your blood into your urine. Your body needs protein, and a lack of protein leads to water retention and swelling. All these symptoms are associated with and known as nephrotic syndrome.
MGN can develop as a primary kidney disease, meaning it’s not caused by another condition. This kind of MGN has no known cause.
However, MGN can also develop as a result of other underlying health conditions. You’re more likely to develop MGN if you:
- have been exposed to toxins such as mercury
- use certain medications, including gold, penicillamine, trimethadione, nonsteroidal anti-inflammatory drugs, or skin-lightening creams
- have infections that affect your immune system such as malaria, hepatitis B, hepatitis C, endocarditis, or syphilis
- have certain types of cancers including melanoma
- have an autoimmune disorder such as lupus, rheumatoid arthritis, or Graves’ disease
- have had a kidney or bone marrow transplant
MGN is very rare. It occurs in two out of every 10,000 people. It’s most commonly diagnosed in people over age 40.
If you have MGN symptoms such as swelling, your doctor may order a urinalysis, which will show if you have protein in your urine. Other tests may also be ordered to confirm diagnosis, including:
- blood and urine albumin
- blood urea nitrogen (BUN)
- creatinine blood
- creatinine clearance
- lipid panel
- blood and urine protein
If these tests indicate the presence of MGN, your doctor may also order a kidney biopsy. Your doctor will obtain a small sample of kidney tissue, which will then be sent to a lab for analysis. The results of this test will help confirm your diagnosis.
Following diagnosis of MGN, your doctor may perform additional tests to see what may be causing your condition. Examples of these tests include:
There’s no cure for MGN, but treatment focuses on controlling your symptoms and immune suppression. You may need to make changes in your diet by reducing your salt and protein intake. You may also need to take medication to help control your blood pressure.
Your doctor may prescribe drugs known as corticosteroids to suppress your immune system and diuretics, or water pills, to reduce swelling. MGN may place you at risk for developing blood clots, and your doctor may prescribe blood-thinning medications to control this.
If MGN is caused by an underlying disorder, your doctor may recommend treatment for that condition as well. The specific treatment plan will be individualized for you. Talk to your doctor to find out what treatments they recommend.
The long-term outlook for people with MGN varies. A majority of people with MGN experience long periods without symptoms and then develop flare-ups. You’ll need to visit your doctor for regular checkups so they can monitor your condition. In some instances, the disease may resolve without treatment.
One third of people who develop MGN develop some irreversible kidney damage within 2 to 20 years of being diagnosed with the disease. After five years, end-stage renal disease (ESRD) or kidney failure occurs in 14 percent of people.