| he kidneys are a vital part of the
body. Their main job is to remove waste products from the blood,
which are passed out of the body in urine. There are about a
million tiny filters in each kidney called glomeruli. If these
filtering units get inflamed (swollen) this is called
glomerulonephritis. It means the kidneys are unable to work
properly. Salt and excess fluid can build up, leading to
complications such as high blood pressure and possibly kidney
failure. There are several types of glomerulonephritis; some
are more serious and long-term than others. Glomerulonephritis
may be short-lived (acute) and need minimal treatment. It may be
present for many years without causing trouble, or it can
develop into a long-term (chronic) condition.
Glomerulonephritis often follows an infection such as an
infection of the throat (pharyngitis).
There are other conditions that cause glomerulonephritis and
swelling in the kidneys such as infection, tumour growth, or
disease within the kidney from long-term use of NSAIDs
(non-steroidal anti-inflammatory drugs) such as aspirin.
Glomerulonephritis is more common in men than women. It often
affects children and young people
Symptoms
There are several types of glomerulonephritis. If it has been
caused by an infection, the early symptoms may include a sore
throat. Inflammation in the kidneys may not be obvious at first.
Symptoms of kidney damage can come on suddenly or appear up to
three weeks after infection.
As a result of damage to the kidneys, glomerulonephritis can
cause:
- swollen ankles,
- a puffy face,
- problems breathing,
- pale skin,
- headaches,
- visual problems,·
- fever,
- loss of appetite and
- vomiting.
In addition, there may be small amounts of blood in the urine
and it may be cloudy. The normal urine output for an adult is
between 0.8 and 2.5 litres per day. This can vary according to a
number of factors such as how much you exercise and how hot or
cold you are. In severe cases of glomerulonephritis, some people
find that they do not urinate at all for 2-3 days. Once they are
able to urinate again, there may still be blood and protein in
the urine.
Some people get pain in the kidneys (in the upper back,
behind the ribs). Kidney pain may be due to a kidney infection
or kidney stones and not glomerulonephritis, so it is important
to see your GP for correct diagnosis.
Causes
Glomerulonephritis is usually caused by changes in the body’s
immune system. This is a complicated process involving antigens
and antibodies. Antigens are foreign substances in the body such
as proteins and toxins. Antibodies circulate in the blood and
their job is to get rid of antigens. If these antigens and
antibodies gather in the kidneys for any reason it can cause an
inflammatory reaction (swelling). This reaction may just affect
the kidney or may cause problems in other parts of the body.
Anyone who already has a chronic (long-term) autoimmune
condition, such as lupus is at risk of developing
glomerulonephritis. An autoimmune condition means that the body
attacks its own cells accidentally.
Commonly, acute glomerulonephritis is linked to streptococci
bacteria (beta haemolytic). This is referred to as acute post
streptococcal glomerulonephritis (ASGN) and can follow a throat
or skin infection.
Glomerulonephritis is also recognised as a serious
complication of some other infections including AIDS/HIV,
Hepatitis B, Hepatitis C, TB and syphilis. For this reason,
injecting drug users are particularly at risk of developing
glomerulonephritis.
Glomerulonephritis is a complication of many other diseases,
including:
- cancer and leukaemia,
- hodgkin’s disease,
- diabetes,
- Goodpasture’s syndrome (an autoimmune disorder that
affects the lungs and kidneys),
- liver disease, and
- sickle cell disease.
It is also recognised as a side effect of long-term use of
certain drugs. Such drugs include, non-steroidal
anti-inflammatory drugs (eg ibuprofen), gold injections (used in
the treatment of rheumatoid arthritis), lithium (used in the
treatment of depression) and penicillamine (used in the
treatment of arthritis). Your GP should monitor your kidney
function with renal tests if you are taking medicines that
affect the function of the kidney.
Diagnosis
Often there are no symptoms at all. Sometimes
glomerulonephritis is only diagnosed following a routine medical
check-up, or during tests related to having high blood pressure,
feeling tired or being pregnant. If you already have kidney
disease, your doctor may want to test for glomerulonephritis.
If you have glomerulonephritis, a urine test will show up
blood and protein in the urine. A range of tests will be carried
out to assess how well your kidneys are working (renal function
tests). These will include blood samples to find out levels of
sodium, chloride, potassium and urea. Tests may show that you
are producing less urine than usual overall.
If glomerulonephritis is suspected, the doctor may take a
throat swab (scraping some cells from the back of your throat) a
sample of to confirm the diagnosis.
Some varieties of glomerulonephritis are more serious than
others. Your doctor may remove and examine a small sample of
kidney tissue (a biopsy) to see how serious the
glomerulonephritis is. This is usually done using local
anaesthetic and a small needle. The test carries a small risk
of bleeding.
Treatment
Treating the original infection:
Streptococci bacteria are usually destroyed with antibiotics
such as penicillin. Other infections may require other types of
antibiotics and/or anti-viral drugs.
Treating glomerulonephritis:
If you have glomerulonephritis the doctor treating you will
focus on treating the cause as well as the condition. You may be
advised to drink less fluid (restrict your fluid intake) and to
avoid certain drinks such as alcohol and drinks with a lot of
sodium chloride (salt) and/or potassium in them. Your diet
should be controlled carefully. Your GP or dietician will give
you advice on eating protein and controlling the your intake of
potassium and salt. Your blood chemistry will be regularly
reviewed to ensure that levels of potassium, sodium and chloride
are at the right level and that the amount of fluid in your diet
is correct. Your treatment may include corticosteroids and a
drug called cyclophosphamide. Other drugs used will relate to
the underlying cause of the condition and the body’s response to
glomerulonephritis.
Treating high blood pressure:
High blood pressure damages the kidney further and causes
other health problems. Your blood pressure will be monitored by
the doctor treating you and may need to take drugs such as ACE (Angiotensin
Converting Enzyme) inhibitors which relax the blood vessels and
reduce the workload of the heart.
Treating chronic kidney disease or kidney failure:
In cases of chronic kidney disease or kidney failure, kidney
dialysis (using a machine to do the kidneys’ job of removing
waste products from the body) or a kidney transplant will be
needed.
| Complications
Possible complications vary according to the type of
glomerulonephritis but can include:
High blood pressure: This is a
common complication of glomerulonephritis, because the
kidneys help control the blood pressure in the body.
Many people with glomerulonephritis are prescribed drugs
to lower blood pressure. It is important to take these
to protect the kidneys against further damage and also
to reduce the risks of heart disease and stroke. If
blood pressure is untreated it can lead to heart failure
and fluid in the lungs (pulmonary oedema).
Disease in other internal organs: In
most patients, glomerulonephritis affects only the
kidneys. However, in some cases, the immune system that
damages the kidneys can also affect other parts of the
body, for example giving a blotchy red rash on the skin
or pain in the joints. Discuss any symptoms you may have
with your doctor to see if they could be related to
glomerulonephritis. If you develop a blotchy red skin
rash you should see your GP immediately.
Kidney disease or kidney failure:
This is rare, but glomerulonephritis can cause so much
damage to the kidneys that they fail completely.
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Prevention
Glomerulonephritis is not generally preventable. Early
detection (especially for people who have conditions linked to
the disease), diagnosis and treatment are important to avoid
other complications.
Streptococcal throat infections should be treated as early as
possible with antibiotics, to avoid kidney damage occurring.
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