IgA nephropathy, also known as IgA Disease or Berger’s Disease after the doctor who first recognised it, is the commonest of a group of conditions, which have the general name glomerulonephritis. Glomerulonephritis is an inflammation of the kidneys, in particular the glomeruli, the microscopic filters which allow the kidney to clear waste products and excess water from the blood.
IgA is an antibody. Antibodies are a part of the body’s natural defences against infection. Everyone has IgA. It is usually found in our blood, the inner lining of the intestine and the airways of the lungs. If you have IgA nephropathy, a very small amount of the IgA has stuck in your kidneys causing inflammation and is stopping the kidneys working properly. The rest of your IgA will be working quite normally, defending you against infection.
It is not yet known why the IgA sticks in the kidney.
The commonest symptom of IgA nephropathy is episodes of blood in the urine (haematuria). This often coincides with a sore throat or respiratory infection. Sometimes the episodes of blood appear to be caused by a bowel infection or even exercise. The urine may look like anything from slightly smoky, through tea without milk (most common), to bright red. It is not usual to see blood clots. It is usually painless, although may be accompanied by kidney discomfort.
Between these episodes of visible blood in the urine, there will still be blood in the urine, which will show if the urine is tested. Some people never get visible blood in their urine.
Sometimes the damage to the kidney causes protein to be lost into the urine. This will show on urine tests. If there is a lot of protein loss, the patient may have fluid retention, which will appear as ankle swelling. This is also called nephrotic syndrome. This is not very common.
Some patients may develop high blood pressure as a result of the kidneys not working properly.
The above symptoms may suggest IgA nephropathy to your doctor. In order to confirm the diagnosis a renal biopsy will be required. Only a very small specimen of the kidney is taken to be examined in the laboratory for IgA. This is to rule out other possible causes for the symptoms. Only one kidney needs to be sampled.
The condition is three times as common in men than women. Nobody yet knows why this is. It is most common in children and young adults, but can develop at any age. Older people are less likely to have the visible blood in their urine, but more likely to have protein and blood in their urine when it is tested. They are also more likely to have high blood pressure and other symptoms of kidney failure. This is because they may have had the disease for longer before it was diagnosed as blood was not visible in the urine.
Very occasionally, a family will have more than one member affected by IgA nephropathy. This is very unusual. As the great majority of patients with IgA nephropathy are the only ones in their families to have the condition, there is no need to test other family members.
The function of many people’s kidneys with IgA nephropathy does not get worse. However, about a quarter of all patients with the disease will develop impaired kidney function and, eventually, kidney failure. But, this may take 20 years or more.
Patients who have more severe symptoms, protein as well as blood in the urine, high blood pressure and high creatinine levels in the blood (a measure of kidney function), are more likely to develop kidney failure. The biopsy will show how much the inflammation has scarred and damaged the kidney. If you have blood in your urine and the biopsy shows just the deposits of IgA stuck in the kidney and very little other damage, the chance of kidney failure is small.
Although it is possible to predict what may happen for each person, it is not possible to be certain. For this reason, IgA nephropathy patients are always monitored regularly, either in the hospital outpatients department or at the GP’s surgery.
Yes, it can. For some people, even the invisible blood in the urine will disappear, leaving no sign of the disease. However, the IgA can still be in the kidney. Although further episodes are unlikely, the blood in the urine can return. The regular check-ups are still needed.
Most people get a few episodes of blood in their urine. There is not a close relationship between the number of attacks and the chance of getting kidney failure later. The attacks do get less frequent, although blood will still be found in the urine on testing.
Just occasionally, an attack will lead to a sudden worsening of the kidneys’ ability to work normally. Normal function is usually restored within a week or two.
No, it does not. There is another condition, called HSP (Henoch-Schonlein purpura), which is similar. Patients with this condition not only have a kidney problem, but also have a skin rash, aches and pains in their joints and abdominal pain. In HSP, IgA is found in the skin as well as the kidneys. The skin, joint and abdominal problems often go away after a few weeks, but the kidney problem can stay much longer and may lead to kidney failure. HSP can occur at any age but is most commonly seen in children.
There are several approaches to consider:
This not yet possible. Research is continuing to look at how this might be achieved, but until it is understood why IgA sticks in the kidneys a treatment will remain unfound.
Blood in the urine can be a dramatic and frightening symptom. Although it looks like a lot, a small amount of blood can colour urine very effectively. It is very unusual to become anaemic from IgA nephropathy. The haematuria will usually settle down in a few days, without any help. Consequently, there is no specific treatment for haematuria.
If the attack started with a sore throat or respiratory infection, the treatment for those infections should be no different to usual. For example, if you have a bacterial sore throat, antibiotics may be required. If it is viral, it will get better on its own.
If you have many attacks due to tonsillitis, you may want to have your tonsils out. But this decision should be based on the amount of trouble that your tonsils are giving you, as there is no proof that this will reduce the chance of kidney failure.
3. Treating IgA nephropathy with steroids and immunosuppressants
It was once thought that, as the condition is caused by the immune system going slightly wrong, giving drugs to suppress the immune system would work. There is no evidence that this treatment option provides any long-term help. Only in a small number of patients with rapidly deteriorating kidneys is this a useful possibility. The drugs have serious potential side effects and the pros and cons need to be discussed with the treating doctor.
A few patients with a lot of protein in the urine (nephrotic syndrome) may be helped with steroids. They can stop the protein loss rapidly, make the patient feel better and perhaps reduce the chance of kidney failure.
4. Treating blood pressure
Raised blood pressure is common in IgA nephropathy and can occur early on when kidney damage is mild. There are two very important reasons for controlling blood pressure.
Blood pressure control using tablets is the best way of reducing the risk of kidney failure from IgA nephropathy
5. Treating Kidney Failure
A quarter of all IgA nephropathy patients eventually develop kidney failure. This happens gradually, usually over a twenty-year period.
When this does happen, patients need a treatment that will replace the function of their kidneys. Different forms of dialysis are offered to patients for them to choose that which best matches their needs. For many, if it can be achieved, the best form of treatment is a kidney transplant. IgA nephropathy does not affect the range of options that are available.
IgA may stick in the new kidney. The immunosuppressants that transplant patients take will not prevent this from happening. This is not as serious as it first appears. The IgA may stick but it will not cause much in the way of inflammation or scarring. Some patients have lost their transplants because of recurrence of the disease in the new kidney. However, if it does happen, it happens slowly as it would have done in your original kidneys. The chance of a successful transplant are not reduced if the cause of your original kidney failure was IgA nephropathy.