Immunoglobulin A (IgA) Nephropathy

What is IgA nephropathy?

IgA nephropathy is a chronic kidney disease. It progresses over 10 to 20 years, and 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 the following:

  • 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 glomerulus. 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. It is not known what causes IgA deposits in the glomeruli. In more than 10% of affected families, it is 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 the age of 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. Very rarely, blood pressure can become dangerously high.

How is IgA nephropathy diagnosed?

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

  • Blood pressure checks
  • Cholesterol test
  • Checking for protein in the urine
  • Checking 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?

Your healthcare provider will figure out the best treatment based on:

  • How old you are
  • Your overall health and past health
  • How sick you are
  • How well you can handle specific medicines, procedures, or therapies
  • How long the condition is expected to last
  • Your opinion or preference

Treatment may include:


  • Blood pressure medicines, such as ACE inhibitors. These 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 such as 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 build-up of plaque in the kidney arteries and further damage to the kidneys.
  • Stop smoking
  • Exercise and maintaining a normal body weight
  • High fluid intake

What are complications of IgA nephropathy?

Complications include:

  • 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. A 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 the 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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