IgA nephropathy is a condition in which a protein causes damage to the kidneys. The protein is called immunoglobulin A or IgA. Nephropathy means an illness that damages the kidney.
The main job of the kidneys is to clear waste materials from the body and maintain a normal balance of fluids and chemicals in the body. The kidneys also have other functions such as helping to control blood pressure.
What causes it?
IgA nephropathy is one of a group of conditions called glomerulonephritis. The cause of IgA nephropathy is not completely understood. IgA is a type of protein (antibody) our body produces to fight infection. IgA becomes trapped in the kidneys and causes damage to the kidneys.
IgA nephropathy is associated with a number of other diseases, including Henoch-Schönlein purpura, systemic lupus erythematosus (SLE), ankylosing spondylitis, cirrhosis and coeliac disease. One type of IgA nephropathy can be inherited and so runs in families.
Read more about the causes of IgA nephropathy.
How common is it?
IgA nephropathy is very uncommon. However, IgA nephropathy is the most common cause of glomerulonephritis. IgA nephropathy most often starts between 16 and 35 years of age.
What are the symptoms?
The symptoms vary from person to person. There are often no symptoms but IgA may cause protein or blood in your urine and may cause high blood pressure.
Occasionally the urine leaks large amounts of protein. This causes the protein level in the body to become very low and causes fluid swelling. This is called the nephrotic syndrome.
The kidneys may become badly damaged and they don't work properly, but this usually happens over a long period of time. See separate leaflet called chronic kidney disease.
Find out more about the symptoms of IgA nephropathy.
How is it diagnosed?
The first tests include urine tests to check for a urine infection and to measure the protein in your urine. Collecting all of your urine over 24 hours may be needed to see how much protein is leaking from your kidneys. Blood tests will include tests to see how well your kidney is working.
The scarring and inflammation in the kidney can only be seen with a microscope. Therefore, IgA nephropathy is normally only diagnosed after a sample (biopsy test of the kidney) is taken.
What are the treatments?
There is no specific treatment and sometimes no treatment is required apart from regular checks of your urine (for protein and blood), blood tests for kidney function and also blood pressure checks. However, treatment is often needed, including:
- It is essential to control your blood pressure. The medicines usually used for blood pressure control with IgA nephropathy are angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) - for example, losartan. ARBs are sometimes called angiotensin-II receptor antagonists.
- As well as controlling blood pressure, ACE inhibitors and ARBs can reduce your risk of developing chronic kidney disease.
Other medicines used for IgA nephropathy may include:
- Steroids, which reduce the amount of protein in your urine and reduce your risk of chronic kidney disease.
- Other medicines to reduce any kidney damage caused by your immune system (for example, azathioprine). These medicines are called immunosuppressants.
- Medicines that prevent blood clotting in your blood vessels have also been used. See separate leaflet called anticoagulants for more information.
- Removing your tonsils (tonsillectomy) may also help by reducing the amount of IgA in your blood.
- Severe kidney damage (end-stage kidney disease) will usually need treatment with dialysis and a kidney transplant.
Read more about the treatments for IgA nephropathy.
What is the outlook?
The outlook (prognosis) is very variable from person to person.
- IgA nephropathy may get better on its own without any further problems.
- IgA nephropathy may continue unchanged for many years. You will then only need regular check-ups with urine and blood tests.
- About 1 in 3 people with IgA nephropathy develop chronic kidney disease.
Did you find this information useful?
- Lai KN, Leung JC, Tang SC; Recent advances in the understanding and management of IgA nephropathy. F1000Res. 2016 Feb 11 5. pii: F1000 Faculty Rev-161. doi: 10.12688/f1000research.7352.1. eCollection 2016.
- Lv J, Xu D, Perkovic V, et al; Corticosteroid therapy in IgA nephropathy. J Am Soc Nephrol. 2012 Jun 23(6):1108-16. doi: 10.1681/ASN.2011111112. Epub 2012 Apr 26.
- Reid S, Cawthon PM, Craig JC, et al; Non-immunosuppressive treatment for IgA nephropathy. Cochrane Database Syst Rev. 2011 Mar 16 (3):CD003962. doi: 10.1002/14651858.CD003962.pub2.
- Vecchio M, Bonerba B, Palmer SC, et al; Immunosuppressive agents for treating IgA nephropathy. Cochrane Database Syst Rev. 2015 Aug 3 (8):CD003965. doi: 10.1002/14651858.CD003965.pub2.
- Cheng J, Zhang X, Tian J, et al; Combination therapy an ACE inhibitor and an angiotensin receptor blocker for IgA nephropathy: a meta-analysis. Int J Clin Pract. 2012 Oct 66(10):917-23. doi: 10.1111/j.1742-1241.2012.02970.x.
- Kamei K, Nakanishi K, Ito S, et al; Long-term results of a randomized controlled trial in childhood IgA nephropathy. Clin J Am Soc Nephrol. 2011 Jun 6(6):1301-7. doi: 10.2215/CJN.08630910. Epub 2011 Apr 14.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.