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 glomerulonephritis; Membranous GN; Extramembranous glomerulonephritis; Glomerulonephritis - membranous; MGN
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.
The following increase your risk for this condition:
The disorder occurs at any age, but is more common after age 40.
Symptoms often begin slowly over time, and may include:
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.
High blood cholesterol and triglyceride levels should be treated to reduce the risk for atherosclerosis. However, a low-fat, low-cholesterol diet is often not as helpful for people with membranous nephropathy.
Medicines used to treat membranous nephropathy include:
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 may need to be replaced if nephrotic syndrome is long-term (chronic) and does not respond to therapy.
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.
Most people with this disease will have kidney damage and some people will develop end-stage renal disease.
Complications that may result from this disease include:
Call for an appointment with your health care provider if:
Quickly treating disorders and avoiding substances that can cause membranous nephropathy may reduce your risk.
Radhakrishnan J, Appel GB. Glomerular disorders and nephrotic syndromes. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 113.
Saha MK, Pendergraft WF, Jennette JC, Falk RJ. Primary glomerular disease. In: Yu ASL, Chertow GM, Luyckx VA, Marsden PA, Skorecki K, Taal MW, eds. Brenner and Rector's The Kidney. 11th ed. Philadelphia, PA: Elsevier; 2020:chap 31.
Salant DJ, Cattran DC. Membranous nephropathy. In: Feehally J, Floege J, Tonelli M, Johnson RJ, eds. Comprehensive Clinical Nephrology. 6th ed. Philadelphia, PA: Elsevier; 2019:chap 20.