- What is Post-Infectious Glomerulonephritis?
- What does it look like (under the microscope?)
- How did I get it?
- What are the symptoms?
- How is Post-Infectious GN diagnosed?
- What is the treatment?
- What is the prognosis?
What is Post-Infectious Glomerulonephritis (GN)?
The main functions of the kidneys are controlling the balance of fluid in your body, filtering your blood, passing the waste products on to your bladder as urine, and controlling blood pressure. Each of your kidneys contains about one million nephrons. Nephrons are small structures that do the work in your kidneys. Each nephron has a small blood vessel that brings in unfiltered blood, a glomerulus which is a tiny ball-shaped structure composed of blood vessels actively involved in the filtration of the blood to form urine, a tubule that carries away filtered waste materials in the urine, and a small blood vessel that returns filtered blood to the body.
Any disease of the glomeruli (plural for glomerulus) must be considered serious because it interferes with the basic functions of the kidneys; that is, filtration of liquids and excretion of waste products.
Post-Infectious Glomerulonephritis is a disease that occurs in the kidneys. It is the result of an infection, not of the kidneys, but of a completely different area, such as the skin or throat. The infection causes glomeruli in the kidneys to become swollen, which makes the kidneys less able to filter and remove wastes. This disorder may begin to develop one to two weeks after an untreated throat infection, and three to four weeks after an untreated skin infection. Although this condition can occur at any age, it is mostly common in children ages six to ten. This condition is also known to affect twice as many males than females.
What does it look like (under the microscope)?
After a kidney biopsy is done, the tissue is looked at under a microscope. In Post-Infectious Glomerulonephritis, the glomeruli appear large, with obvious hypercellularity (increased number of inflammatory cells).
In some cases, it is possible to see well-defined rounded deposits outside of the capillary walls which look like humps. The presence of these humps may be a sign of Post-Infectious Glomerulonephritis, but it can be seen in other types of glomerulonephritis.
How did I get it?
Your immune system protects you against diseases by finding and killing bacteria. Bacteria and its toxins, which are called antigens, activate your immune system. Your immune system then builds antibodies which bind to the antigen; this binding activates another part of your immune system which is called the complement system, which is responsible for destroying these bacteria. In other words, antibodies find the target and complement destroys it.
In the
case of Post-Infectious Glomerulonephritis, these immune complexes (formed from antigen, antibodies, and complement) get trapped in your glomeruli. The glomeruli become inflamed, which leads to inefficient kidney function. Not everybody who has a sore throat or skin infection develops this type of glomerulonephritis. For this reason it is thought that there are some genetic factors that put people at risk for this.
What are the symptoms?
The symptoms of this condition are fluid retention with swelling (generalized swelling; swelling of the abdomen; swelling of the face or eyes; swelling of the feet, ankles, and extremities), high blood pressure, coca-cola colored urine, blood in the urine, decreased amount of urine, joint stiffness and joint pain.
How is Post-Infectious Glomerulonephritis diagnosed?
- Abnormal sounds are heard when listening to the heart and lungs with a stethoscope.
- Blood pressure is often high
- Physical examination shows swelling (edema), especially of the face
- Blood testing shows abnormalities, such as elevated Anti-DNase B and serum ASO, which are indicators of a specific type of recent infection.
- Serum complement levels are usually decreased
- Urinalysis shows protein and blood in the urine
- Kidney biopsy confirms Post-Infectious Glomerulonephritis, although biopsy is not usually necessary
What is the treatment?
There is no specific treatment for Post-Infectious Glomerulonephritis. Treatment is focused on relieving symptoms. Antibiotics, such as penicillin, should be used to treat any bacterial infection. Blood pressure medications and diuretic medications may be needed to control swelling and high blood pressure. Dietary salt restriction may be necessary to control swelling and high blood pressure.
What is the outlook or prognosis?
Post-Streptococcal Glomerulonephritis usually goes away by itself after several weeks to months. In a small number of adults, it may progress to chronic kidney failure.
