Glomerulonephritis is a disease of the kidneys in which there is inflammation of the filtering units, called glomeruli. This inflammation can cause protein and red blood cells to leak into the urine while toxins normally removed by the kidney are retained in the body. Kidney failure develops when the kidney becomes less effective at filtering out waste products, water and salt from the blood.
There are many types and causes of glomerulonephritis. These include:
- Prior infection: For example, after a streptococcal infection (such as strep throat), kidney failure may develop with associated problems of high blood pressure, dark urine, and swelling in the legs. Glomerulonephritis following streptococcal bacterial infection is among the most common types of post-infectious disease, especially among children.
- Autoimmune: With conditions such as systemic lupus erythematosus (SLE) or blood vessel inflammation (vasculitis), the body's immune system mistakenly attacks healthy tissue. When the kidney's filtering system is the target, glomerulonephritis may develop.
- Antibody-mediated: The most common type is called IgA nephropathy. While this can be associated with liver disease, celiac disease or HIV infection, many cases are of unknown cause. Immunoglobulin A, an antibody that normally helps fight off infection, is deposited in the kidney, leading to hematuria (blood in the urine) but less commonly more serious problems.
- Membranous glomerulonephritis: This condition may develop as part of lupus or on its own. The hallmark of this type of kidney disease is the leakage of protein into the urine.
- Rapidly progressive glomerulonephritis: This condition may be diagnosed when there is kidney inflammation and loss of kidney function over weeks to months. Triggers include infections, autoimmune disease, and certain types of antibody-mediated kidney disease.
- Idiopathic: When glomerulonephritis develops for no apparent reason it is called "idiopathic." It's possible that an undetected or undiagnosed infection or a hereditary cause led to kidney inflammation and damage.
If glomerulonephritis is mild, it may not cause any symptoms. In that case, the disease may be discovered only if protein or blood is found in the urine during a routine test. In other people, the first clue can be the development of high blood pressure. If symptoms appear, they can include swelling around the feet, ankles, lower legs, and eyes, reduced urination and dark urine (due to the presence of red blood cells in the urine).
High levels of protein in the urine can cause the urine to appear foamy. If severely elevated blood pressure develops, some people will have headaches (although most people with high blood pressure have no symptoms and most headaches are unrelated to blood pressure). Fatigue, nausea and tremulousness are other common symptoms of kidney failure due to glomerulonephritis. In severe cases, confusion or coma may develop.
Your doctor will ask you about symptoms of a prior infection, family history, or symptoms of conditions that can affect the kidneys. For example, joint pain and rash are the most common symptoms of lupus. Your doctor will ask how often you are urinating, how much urine you are producing and the color of the urine. To check for a history of swelling, your doctor may ask whether you've noticed puffiness around your eyes, unusual tightness in your shoes or waistband or a feeling of heaviness in your legs or ankles.
During your physical examination, your doctor will measure your blood pressure, weigh you to check for weight gain resulting from water retention, and check for swelling in your legs or elsewhere. A complete physical examination is important to look for evidence of other organ involvement such as arthritis or rash.
To confirm the diagnosis of glomerulonephritis, your doctor will evaluate your kidney function through blood tests and an analysis of the urine (called a urinalysis) that detects blood, protein or signs of infection. You also may need specialized blood testing to check for specific autoimmune disease. A kidney biopsy, in which a tiny piece of kidney tissue is removed and examined in a laboratory, is the most helpful test when glomerulonephritis is suspected.
How long glomerulonephritis lasts depends on its cause and on the severity of kidney damage. When glomerulonephritis follows an infection, the problem usually goes away within weeks to months. In other cases, glomerulonephritis becomes a chronic (long-lasting) condition that lasts for years and eventually can lead to kidney failure.
To prevent glomerulonephritis following an infection, the infection must be treated promptly.
Most forms of glomerulonephritis cannot be prevented. Once kidney disease, such as glomerulonephritis is present, avoiding certain medications (such as ibuprofen, naproxen or other anti-inflammatory drugs) can prevent sudden worsening. Complications of kidney disease, such as anemia and bone problems, may be prevented or minimized by appropriate monitoring and timely medical treatment.
When glomerulonephritis is caused by an infection, the first step in treatment is to eliminate the infection. If bacteria caused the infection, antibiotics may be given. However, children who develop the disease following a streptococcal infection often recover without any specific treatment.
When glomerulonephritis has slowed the amount of urine a person is producing, he or she may be given medications called diuretics, which help the body to rid itself of excess water and salt by producing more urine. More severe forms of the disease are treated with medications to control high blood pressure, as well as changes in diet to reduce the work of the kidneys. Some people with severe glomerulonephritis may be treated with medications called immunosuppressive drugs, which decrease the activity of the immune system. Such medications include azathioprine (Imuran), corticosteroids (Prednisone, Methylprednisolone), cyclophosphamide (Cytoxan), rituximab (Rituxan) or mycophenolate mofetil (CellCept). Plasma exchange, a procedure during which substances thought to cause inflammation and kidney damage are removed from the blood, can be helpful in certain types of autoimmune or antibody-mediated glomerulonephritis. When glomerulonephritis progresses to severe, irreversible renal failure, treatment options include dialysis or a kidney transplant.
When To Call A Professional
Call your doctor if you or your child is putting out less urine then normal or if urine looks bloody or abnormally dark. Also call your doctor if you notice unusual swelling, particularly around the eyes or in the legs or feet. If you have a history of a kidney problem and you develop any of these symptoms, you should seek medical assistance without delay.
Children with glomerulonephritis usually recover completely if their illness is mild or if it develops following a strep infection. Although adults often have a poorer outlook, many recover completely. More severe forms of the disease may eventually lead to chronic kidney disease or kidney failure, which may ultimately require lifelong treatment with dialysis or a kidney transplant.