Understanding Immunoglobulin A Nephropathy (IgAN)

What is Immunoglobulin A (IgA)?

IgA are proteins, also called antibodies, made by your immune system to protect your body from bacterial and viral infections. IgA proteins are known as the first line of defense for the body to fight infections. When too much of abnormal IgA deposits in the kidney, they can cause inflammation and slowly damage the kidneys, reducing their ability to function over time.

What is Immunoglobulin A nephropathy (IgAN)?

Immunoglobulin A nephropathy (IgAN) is a rare kidney disease that has an incidence of approximately 1.3 cases per 100,000 individuals per year in the United States. IgAN occurs when too much abnormal IgA accumulates in the kidneys causing inflammation and gradually impairs the kidneys from filtering toxic materials from your blood. Damage to the kidneys could also lead to more protein spilling into the urine, also known as proteinuria. In IgAN, more proteinuria is an indication that you may be at risk of developing kidney failure (also known as end stage kidney disease).

IgAN is also known as Berger’s disease because it is named after one of the two French physicians, Jean Berger, that discovered the condition.

What causes IgA nephropathy?

IgAN is an autoimmune disease that attacks the kidneys. An autoimmune disease means the body’s immune system attacks healthy cells. IgAN can be triggered by a respiratory or a gastrointestinal infection that leads to the production of abnormal IgA. IgAN can have a genetic component which means a person may be more likely to develop IgAN if there is a family history of IgAN.

Some of the symptoms include:

    • Hematuria (blood in urine)*
    • Foamy urine (because of protein in urine)
    • Swelling in the feet, ankles, or legs
    • High blood pressure
    • High cholesterol
    • Extreme fatigue

*Hematuria is typically the first symptom that appears

presence of blood in your urine 

high levels of protein in your urine

infographic image

Did you know?

40% of people living with IgAN were not aware of their  symptoms prior to their diagnosis.

Who is at-risk for IgA nephropathy?

Risk factors for IgAN include:

  • A family history of IgAN 
  • IgAN often appears during the teenage years and into the late 30s
  • Asian or White ethnicity
  • More common in men
Can IgA nephropathy be treated?

There is no cure for IgAN. IgAN can get worse over time so managing the symptoms is necessary to prevent worsening of the disease. The earlier you manage your symptoms, the slower your disease will progress.

  • Treatment will be directed towards managing your symptoms:
  • Blood pressure control to reduce the amount of protein in your urine
  • Diuretic (“water pill”) to help the kidneys remove excess fluid from the blood
  • Corticosteroids to reduce inflammation 
  • Medication to manage cholesterol levels
  • Limiting sodium (salt) in your diet
How do I know if I have IgA nephropathy?

If you have symptoms, it is important to see your healthcare provider. The most common symptom of IgAN is blood in the urine. Blood in the urine may present as tea-colored or cola-colored urine. Your healthcare provider will conduct a thorough physical exam, including understanding your past family and medical history, and perform blood and urine test. The blood tests may include screening your kidney function and cholesterol levels. The urine tests may include a urinalysis and a 24-hour urine test to check the amount of protein that is present in the urine.

infographic image

Did you know?

40% of people living with IgAN have no recognizable symptoms when their disease is first suspected.

Should I be tested for IgA nephropathy?

There are several tests your healthcare provider may perform to evaluate your symptoms, such as blood and urine, but the definitive way of knowing whether you have IgAN is a kidney biopsy. A kidney biopsy will help confirm the diagnosis as well as determine the extent of damage to the kidneys.

Kidney biopsy:
a procedure that involves inserting a thin needle through the skin directly into the kidney, often using ultrasound to guide the procedure, and taking small pieces of the kidney to examine under a microscope

Can IgA nephropathy hurt my kidneys?

Yes! Abnormal IgA depositing in your kidneys can directly cause inflammation and damage to your kidneys. If left untreated, over time, your kidney function may worsen and could eventually require the need for dialysis or a kidney transplant. Higher levels of protein in your urine is an indicator that you are at risk for kidney failure.

Which medications are used to treat IgAN?

The medications your healthcare provider prescribes for you will be targeted to manage your symptoms. Some of the medications may include:

  • High blood pressure medications 
  • High cholesterol medications
  • Diuretics (“water pill”)
  • Corticosteroids

In many cases, use of these treatments may not help reduce proteinuria. When these don't help, your healthcare provider may discuss enrolling into a clinical trial.

What are complications related to IgAN?

  • High blood pressure
  • High cholesterol
  • Heart or cardiovascular problems
  • Kidney failure

For additional resources, visit:

This AAKP patient education web page is supported by an educational donation by Chinook Therapeutics. The educational content shown is unbranded and unbiased and has not been determined or influenced by any sponsor(s). It’s intended for educational purposes only.

Learn more about kidney disease from fellow patients, healthcare professionals, and the renal community by reading these articles produced for AAKP.
Educational Brochures and Resources
AAKP offers a variety of educational resources for people living with kidney disease and their care partners.
aakpRENALIFE and E-Newsletters
AAKP offers a bi-monthly magazine as well as five e-newsletters. Check out our recent issues and subscribe.
HealthLine Webinars
The AAKP HealthLine is a webinar-based program educates patients and their family members on a variety of important health care topics from the comfort of their home or office.