Membranous nephropathyMembranous glomerulonephritis; Membranous GN; Extramembranous glomerulonephritis; Glomerulonephritis - membranous; MGN
Membranous nephropathy is a kidney disorder that leads to changes and inflammation of the structures inside the kidney that help filter wastes and fluids. The inflammation may lead to problems with kidney function.
Membranous nephropathy is caused by the thickening of a part of the glomerular basement membrane. The glomerular basement membrane is a part of the kidneys that helps filter waste and extra fluid from the blood. The exact reason for this thickening is not known.
The thickened glomerular membrane does not work normally. As a result, large amounts of protein are lost in the urine.
This condition is one of the most common causes of nephrotic syndrome. This is a group of symptoms that include protein in the urine, low blood protein level, high cholesterol levels, high triglyceride levels, and swelling. Membranous nephropathy may be a primary kidney disease, or it may be associated with other conditions.
Nephrotic syndrome is a group of symptoms that include protein in the urine, low blood protein levels in the blood, high cholesterol levels, high tri...
The following increase your risk for this condition:
- Cancers, especially lung and colon cancer
- Exposure to toxins, including gold and mercury
- Infections, including hepatitis B, malaria, syphilis, and endocarditis
Hepatitis B is irritation and swelling (inflammation) of the liver due to infection with the hepatitis B virus (HBV). Other types of viral hepatitis ...
- Medicines, including penicillamine, trimethadione, and skin-lightening creams
- Systemic lupus erythematosus, rheumatoid arthritis, Graves disease, and other autoimmune disorders
The disorder occurs at any age, but is more common after age 40.
Symptoms often begin slowly over time, and may include:
- Edema (swelling) in any area of the body
- Foamy appearance of urine (due to large amounts of protein)
- Poor appetite
- Urination, excessive at night
- Weight gain
Exams and Tests
A physical exam may show swelling (edema).
A urinalysis may reveal a large amount of protein in the urine. There may also be some blood in the urine. The glomerular filtration rate (the "speed" at which the kidneys cleanse the blood) is often nearly normal.
Urinalysis is the physical, chemical, and microscopic examination of urine. It involves a number of tests to detect and measure various compounds th...
Protein in the urine
The protein urine dipstick test measures the presence of proteins, such as albumin, in a urine sample. Albumin and protein can also be measured using...
Blood in the urine
Blood in your urine is called hematuria. The amount may be very small and only detected with urine tests or under a microscope. In other cases, the...
Other tests may be done to see how well the kidneys are working and how the body is adapting to the kidney problem. These include:
- Albumin - blood and urine
- Blood urea nitrogen (BUN)
- Creatinine - blood
- Creatinine clearance
- Lipid panel
- Protein - blood and urine
A kidney biopsy confirms the diagnosis.
A kidney biopsy is the removal of a small piece of kidney tissue for examination.
The following tests can help determine the cause of membranous nephropathy:
- Antinuclear antibodies test
- Anti-double-strand DNA, if the antinuclear antibodies test is positive
- Blood tests to check for hepatitis B, hepatitis C, and syphilis
- Complement levels
- Cryoglobulin test
The goal of treatment is to reduce symptoms and slow the progression of the disease.
Controlling blood pressure is the most important way to delay kidney damage. The goal is to keep blood pressure at or below 130/80 mm Hg. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) are the medicines most often used to lower blood pressure.
Corticosteroids and other drugs that suppress the immune system may be used.
High blood cholesterol and triglyceride levels should be treated to reduce the risk of atherosclerosis. However, a low-fat, low-cholesterol diet is often not as helpful for people with membranous nephropathy. Medicines to reduce cholesterol and triglyceride levels (most often statins) may be recommended.
High blood cholesterol
Cholesterol is a fat (also called a lipid) that your body needs to work properly. Too much bad cholesterol can increase your chance of getting heart...
Hardening of the arteries, also called atherosclerosis, occurs when fat, cholesterol, and other substances build up in the walls of arteries. These ...
The triglyceride level is a blood test to measure the amount of triglycerides in your blood. Triglycerides are a type of fat. Your body makes some t...
A low-salt diet may help with swelling in the hands and legs. Water pills (diuretics) may also help with this problem.
Low-protein diets may be helpful. A moderate-protein diet (1 gram [gm] of protein per kilogram [kg] of body weight per day) may be suggested.
Vitamin D is a fat-soluble vitamin. Fat-soluble vitamins are stored in the body's fatty tissue.
Chronic refers to something that continues over an extended period of time. A chronic condition is usually long-lasting and does not easily or quick...
This disease increases the risk for blood clots in the lungs and legs. Blood thinners may be prescribed to prevent these complications.
The outlook varies, depending on the amount of protein loss. There may be symptom-free periods and occasional flare-ups. Sometimes, the condition goes away, with or without therapy.
Injury to the kidney and ureter is damage to the organs of the upper urinary tract.
End-stage renal disease
End-stage kidney disease is the last stage of chronic kidney disease. This is when your kidneys can no longer support your body's needs. End-stage k...
Complications that may result from this disease include:
- Chronic renal failure
- Deep venous thrombosis
- End-stage renal disease
- Nephrotic syndrome
- Pulmonary embolism
- Renal vein thrombosis
When to Contact a Medical Professional
Call for an appointment with your health care provider if:
- You have symptoms of membranous nephropathy
- Your symptoms get worse or don't go away
- You develop new symptoms
- You have decreased urine output
Quickly treating disorders and avoiding substances that can cause membranous nephropathy may reduce your risk.
Manoharon A, Schelling JR, Diamond M, Chung-Park M, Madaio M, Sedor JR. Immune and inflammatory glomerular diseases. In: Alpern RJ, Moe OW, Caplan MJ, eds. Seldin and Giebisch's The Kidney. 5th ed. Philadelphia, PA: Elsevier; 2013:chap 82.
Salant DJ, Cattran DC. Membranous nephropathy. In: Johnson RJ, Feehally J, Floege J, eds. Comprehensive Clinical Nephrology. 5th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 20.
Kidney anatomy - illustration
The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and stimulating red blood cell production.
Review Date: 9/22/2015
Reviewed By: Charles Silberberg, DO, private practice specializing in nephrology, affiliated with New York Medical College, Division of Nephrology, Valhalla, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.