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Immunoglobulin A (IgA) Nephropathy

What is IgA nephropathy?

IgA nephropathy is a chronic kidney disease. It progresses over 10 to 20 years, and it can lead to end-stage renal disease. It is caused by deposits of the protein immunoglobulin A (IgA) inside the filters (glomeruli) in the kidney. These glomeruli normally filter waste and excess water from the blood and send them to the bladder as urine. However, the IgA protein prevents this filtering process. This may lead to:

  • Blood and protein in the urine (hematuria and proteinuria)

  • Swelling in the hands and feet (edema)

This is the most common cause of inflammation in the glomeruli. It is more common in Caucasian and Asian people. It is most often found in people in their teens to late 30s.

What causes IgA nephropathy?

The IgA protein is a normal part of the body's immune system. The causes of IgA deposits in the glomeruli are not known. In more than 10% of affected families, it's inherited. Some people who inherit the gene may not have any symptoms but could pass the gene on. Men are affected more often than women.

What are the symptoms of IgA nephropathy?

IgA nephropathy is a silent disease that may go unseen for years. It can happen at any age, but symptoms most often start before age 40. The most common symptom is blood in the urine (hematuria). It takes many years to progress to the stage where it causes problems. These include swelling, recurrent upper respiratory infections, or intestinal disease. People with IgA nephropathy may also have flank pain and a low fever. In very rare cases, blood pressure can become dangerously high.

How is IgA nephropathy diagnosed?

Your healthcare provider will review your health history and do a physical exam. Other tests may include:

  • Blood pressure checks

  • Cholesterol test

  • Tests for protein in the urine

  • Tests for protein in the blood

  • Kidney biopsy (to identify IgA deposits). For this test, a sample of kidney tissue is removed and examined under a microscope.

What is the treatment for IgA nephropathy?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment may include:


  • Blood pressure medicines. This includes ACE inhibitors. Blood pressure medicines help lower blood pressure and protect the kidneys. They also help to prevent protein loss in the urine. Pregnant women should not take these medicines.

  • Corticosteroids. These reduce inflammation and scar tissue inside of the kidney.

  • Prescription strength fish oil. This helps to reduce inflammation and damage within the kidney.

  • Cholesterol-lowering medicines. This includes statins. People with kidney damage are at a higher risk for stroke and heart attack. Controlling cholesterol can help reduce the risk for both.

Other treatments

  • Diet changes to reduce fat and cholesterol. These can cause buildup of plaque in the kidney arteries and further damage to the kidneys.

  • Smoking cessation

  • Exercise and weight loss, if needed

  • High fluid intake

What are possible complications of IgA nephropathy?

Complications include:

  • Kidney failure

  • High blood pressure

  • High cholesterol

When should I call my healthcare provider?

If your symptoms get worse or you have new symptoms, let your healthcare provider know.

Key points about IgA nephropathy

  • IgA nephropathy is a disease in which IgA protein builds up in and damages the filtering part of the kidney (glomerulus).

  • The damage may cause few or no symptoms. Blood in the urine is the most common symptom.

  • The condition is diagnosed by blood and urine tests. Kidney biopsy may also be needed.

  • Treatment is aimed at protecting the kidney from further damage by controlling blood pressure, cholesterol, and inflammation.

  • Regular testing is done to check kidney function.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.

  • Before your visit, write down questions you want answered.

  • Bring someone with you to help you ask questions and remember what your provider tells you.

  • At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

  • Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

  • Ask if your condition can be treated in other ways.

  • Know why a test or procedure is recommended and what the results could mean.

  • Know what to expect if you do not take the medicine or have the test or procedure.

  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.

  • Know how you can contact your provider if you have questions.

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