Glomerulosclerosis refers to scarring or hardening of the glomeruli -- blood vessels located in the kidneys. The glomeruli filter the blood as it passes through the kidneys. They remove waste fluids that then leave the body as urine.
Damaged glomeruli can't perform their job adequately. As a result, large amounts of protein from the blood leak into the urine rather than remaining in the bloodstream. This leads to a condition called proteinuria.
Glomerulosclerosis can affect children and adults. Men are slightly more likely to develop it. African-Americans are at higher risk than whites.
Causes of Glomerulosclerosis
Focal segmental glomerulosclerosis (FSGS) is a kidney disease that can lead to glomerulosclerosis. In FSGS, the scarring occurs only in some of the glomeruli. And only part of the individual glomeruli is damaged.
Untreated, it can lead to kidney failure. In some cases, kidney failure can occur despite treatment.
FSGS most frequently occurs without a cause. In such cases it is called idiopathic or primary FSGS. Sometimes, though, FSGS does have a known cause, and these can include:
- HIV infection
- Sickle cell disease
- Birth defects of the kidneys
- Heroin or other drug use
- Genetic causes (in rare cases)
Besides FSGS, glomerulosclerosis can be caused by these diseases:
Conditions that damage the kidneys can also lead to glomerulosclerosis. These include:
- Glomerulonephritis, which causes the glomeruli to become inflamed
- Reflux nephropathy, in which urine flows back into the kidney
Chemicals and medicines that harm the kidneys can also cause glomerulosclerosis.
Symptoms of Glomerulosclerosis
At first, there are no obvious signs of glomerulosclerosis. Over time, symptoms can develop. These include:
Swelling. Because of fluid retention, you may have swelling in various parts of the body, including:
The swelling may be painful. It may also cause rapid weight gain.
Changes in urine. You may have foamy or bubbly urine, caused by proteinuria.
Often, glomerulosclerosis is discovered during a routine checkup. Tests during a checkup can reveal an abnormally high protein content in the urine (proteinuria). Or they may show a low level of protein in the blood (hypoproteinemia).
Symptoms that often accompany glomerulosclerosis include:
In glomerulosclerosis patients, high blood pressure can be difficult to control.
Diagnosis of Glomerulosclerosis
The only way you can be certain of an accurate diagnosis of glomerulosclerosis is to get a kidney biopsy. That's because the symptoms of glomerulosclerosis can also occur in many other conditions.
In a kidney biopsy, your doctor removes a very small amount of kidney tissue. The tissue is examined for signs of scarring.
Diagnosing glomerulosclerosis may require multiple biopsies. That's because the scarring does not occur throughout the kidney. So your doctor may have to look at samples from several different parts of the kidney until an affected area is found.
Other tests that may be ordered include:
- Glomerular filtration rate (measures kidney function)
- Kidney ultrasound
- Genetic testing
Treatment of Glomerulosclerosis
There is no cure for glomerulosclerosis. And the FDA has not approved any drugs specifically for its treatment.
But several treatments can slow its progression and control symptoms. These include:
- Angiotensin converting enzyme inhibitors (ACE inhibitors) and angiotensin receptor blockers (ARBs). These are blood pressure drugs that help control protein loss.
- Steroids such as prednisone or prednisolone and other immune system-suppressing drugs to reduce protein loss and improve kidney function
- Statins to control cholesterol
- Anticoagulants to prevent blood clots
- Diuretics, or water pills, to remove excess salt from the body; this reduces swelling.
- Low-salt diet, exercise, and vitamins
If glomerulosclerosis was caused by another condition, such as obesity, infection, or an illness such as diabetes, treatment of that condition will be a priority of therapy. Treatment will also include regular monitoring of the kidneys with blood and urine tests.