What is glomerulonephritis?
Glomerulonephritis is a medical term for a family of diseases involving damage to the glomeruli (the tiny filters in the kidney), usually caused by the body’s immune system.
There are many types of glomerulonephritis including:
- Focal and segmental glomerulosclerosis (FSGS)
- IgA glomerulonephritis
- IgM glomerulonephritis
- Membranoproliferative glomerulonephritis (also called mesangiocapillary)
- Membranous glomerulonephritis
- Minimal change nephropathy
- Vasculitis (including Wegener’s granulomatosis)
Causes of glomerulonephritis
The usual job of the immune system is to fight invaders into the body, such as germs or bugs, and destroy them.
It does this by using two main natural weapons which are found in the blood:
- White blood cells, which stick to germs and kill them.
- Tiny antibodies, which also stick onto germs to make them explode (with the help of a family of molecules called ‘complement’) or to make it easier for the white blood cells to stick to the germs.
The immune system is normally very good at recognising what is part of the body and what is not. However, sometimes it makes a mistake and, in some cases of glomerulonephritis, attacks the glomeruli, believing that the filters are alien invaders .
It is not clear why glomerulonephritis occurs. Sometimes a trigger, such as an infection, may make the immune system go wrong.
Other forms of glomerulonephritis can arise for different reasons. One strain of the disease is caused by the production of a particularly sticky form of a protein called immunoglobulin A (IgA) which becomes trapped in the glomeruli, causing damage and scarring to the whole kidney. In other examples, antibodies, sent out to attack problems elsewhere in the body, can get stuck in the kidney and then start to attack it.
Many people with glomerulonephritis have no symptoms at all and feel completely well.
The only sign of damage to the glomeruli may be small amounts of blood or protein that have slipped through the damaged filters into the urine. This can only be detected with urine tests
Sometimes more blood can be lost through the filters, so the urine turns red (known as haematuria). Sometimes, this visible blood in the urine only occurs when the patient with glomerulonephritis is ill for some other reason, like a respiratory infection. There can also be a greater loss of protein through the filters, which can make urine become very frothy. Some people also develop fluid retention in the body, a condition called nephrotic syndrome.
In some cases the damage to the kidney can be so severe that it causes kidney failure – which can also be described as End Stage Kidney Disease.
Some people with glomerulonephritis may experience:
- High blood pressure – which needs to be controlled to protect the kidneys from further damage and to reduce the risk of heart disease and stroke.
- Pain – Most patients with glomerulonephritis do not get pain around the kidneys, but in a few cases it can be severe, particularly during bouts of haematuria.
- Damage to other parts of the body –some forms of glomerulonephritis can affect other parts of the body, perhaps causing a blotchy red skin rash or painful joints.
If glomerulonephritis is suspected, blood tests will be done to look for abnormal antibodies in the blood.
A kidney biopsy (a medical procedure to take small samples of the kidney away for testing) may also be required to make an accurate diagnosis. It may also help to show whether the condition is likely to become serious and which treatments could help.
Some types of glomerulonephritis can run in families. Diagnosis usually requires analysis of your DNA. If one of these conditions is diagnosed, a kidney specialist can give advice about the chances of family members being affected, and whether screening should be done.
Some types of glomerulonephritis can be cured, others can be stopped, and most can at least be slowed down. However, sometimes glomerulonephritis can recur (come back) after a person has had a kidney transplant.
Treatments (depending on the type of glomerulonephritis) include:
- Medicine to control blood pressure
- Drugs that dampen down the immune system and reduce inflammation in the kidney (immunosuppressants). These are strong drugs which can have serious side-effects. Because of this they are often only used for those patients with severe disease or rapidly worsening kidney function.
Resources about glomerulonephritis
Don’t hesitate to speak to your kidney specialist if you have any questions or concerns about your illness.
You can also find further information, advice and helpful tips in our Just diagnosed and How can I help myself? sections.
- Minimal change nephropathy National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Membranous nephropathy EDREN
- IgA nephropathy International IgA Nephropathy Network
- IgA nephropathy National Kidney Federation (NKF)
- IgA nephropathy EDREN
- IgA nephropathy NIDDK
- Lupus nephritis NKF
- Lupus nephritis (SLE) EDREN
- Focal segmental glomerulsclerosis EDREN
- Nephrotic syndrome EDREN
- IgM nephropathy NKF
- Membranoproliferative glomerulonephritis NKF
- Vasculitis NKF
- Vasculitis EDREN
The need for more research
We still don’t understand enough about glomerulonephritis. Research, some of it funded by Kidney Research UK, is needed to answer many questions:
- Exactly what causes each type of glomerulonephritis, and why does the disease occur in some people and not others?
- How can we best make a diagnosis of glomerulonephritis?
- What are the best treatments for each type of glomerulonephritis?
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