IgA nephropathy (Berger’s disease) is a chronic kidney disease that occurs when immunoglobulin A (IgA) deposits build up in the kidneys. It can cause blood in the urine, among other symptoms.

Immunoglobulins are parts of the immune system that help your body get rid of infections. People with IgA nephropathy have a defective version of immunoglobulin A. The defective IgA forms chains that get stuck in the kidneys.

Treatment typically involves controlling your blood pressure and cholesterol levels with medications. Some people with IgA nephropathy may eventually need a kidney transplant.

In the early stages of IgA nephropathy, the main symptom is blood in the urine. In medical terms, this is called hematuria.

Symptoms usually start between ages 10 and 40. But they may go unnoticed for years because the amount of blood in the urine is small.

If the disease progresses and starts to impair your kidney function, you may also experience:

  • brown or tea-colored urine
  • pain on the side of your back (flank pain)
  • protein in the urine (proteinuria)
  • high blood pressure (hypertension)
  • swelling of the hands and feet

An immunoglobulin or antibody is a large protein that the immune system uses to kill harmful bacteria and viruses. One type of immunoglobulin is immunoglobulin A or IgA.

When someone has IgA nephropathy, their IgA doesn’t work properly. Instead of binding only to bacteria and viruses, the IgA mistakenly attaches to other IgA molecules and creates long chains.

As the chains circulate in the blood, they eventually get deposited in the kidney’s filters (glomeruli). These IgA deposits cause an inflammatory reaction, which can ultimately cause kidney damage.

Researchers still do not definitively understand why this happens. The likely cause involves a combination of genetic and environmental factors. IgA nephropathy can run in families.

Some factors can increase a person’s risk of developing IgA nephropathy. The condition is also more common in:

  • people of white European descent
  • people of Pacific Asian descent
  • people assigned male at birth

Other conditions associated with IgA nephropathy include:

A doctor may first notice IgA nephropathy when a routine test reveals protein and red blood cells in your urine.

A doctor typically reviews your medical and family history and performs a physical exam to diagnose IgA nephropathy. They may also ask you about your symptoms, including if you’ve ever noticed that your urine is dark or reddish, or if you’ve had a history of urinary tract infections (UTIs).

They may recommend the following tests:

There’s no cure for IgA nephropathy, and treatment can vary, depending on the severity.

Some people may not need treatment, but a doctor will likely recommend regular checkups on their kidney function.

For others, treatment goals may include slowing the condition’s progress and managing other symptoms, like:

  • blood pressure
  • swelling
  • urine protein levels

This might include one or more of the following:

  • blood pressure medications known as angiotensin receptor blockers (ARBs) or angiotensin-converting enzyme (ACE) inhibitors, which can lower blood pressure as well as urine protein levels
  • immunosuppressant drugs, such as oral steroids
  • omega-3 fatty acid supplements, like a prescription-strength fish oil
  • cholesterol medications, known as statins
  • diuretics, which help remove excess fluid from the blood

In some people, IgA nephropathy may progress over a few decades and can eventually lead to kidney failure.

People with kidney failure will need dialysis, a process where the blood is filtered with a machine, or a kidney transplant. Even after a transplant, the condition can come back in the new kidney.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) recommends limiting sodium intake to lower your blood pressure and help reduce swelling.

You can try following a diet similar to the DASH diet to reduce your sodium intake. DASH stands for dietary approaches to stop hypertension. This diet focuses on fruits, vegetables, whole grains, and lean meats and reducing your sodium intake.

Since the DASH diet is meant to help people lower their blood pressure, it may be helpful for people with IgA nephropathy who need to keep their blood pressure levels within a specific range.

Based on the results of lab tests and your symptoms, a doctor may recommend additional dietary changes.

IgA nephropathy varies greatly from person to person. Some people won’t experience any complications, and the disease may even go into remission on its own.

Other people, however, develop complications as their condition progresses. These can include:

There’s no cure for IgA nephropathy and no reliable way to tell how it will affect each person individually. For most people, the disease progresses slowly.

Research from 2018 suggests having IgA nephropathy can decrease a person’s lifespan by about 10 years.

Roughly 20% of people with IgA nephropathy typically develop ESRD within 10 years of onset. Some signs may indicate an unfavorable prognosis, including:

  • long-term hypertension
  • persistent blood in the urine
  • prolonged protein in the urine (above 1 gram/day)
  • high serum creatinine level
  • widespread intestinal fibrosis of the kidneys

People with ESRD require dialysis treatment or a kidney transplant. A kidney transplant is typically successful, but IgA nephropathy can come back (recur) in the new kidney.

About 20-40% of people will have symptom recurrence after a kidney transplant. Recurrence typically happens within 2.5 years after transplantation but can occur before or after that.

A doctor will work with you to develop a treatment plan if you’re diagnosed with IgA nephropathy.

What is the main cause of IgA nephropathy?

Researchers do not fully understand the cause of IgA nephropathy, but it likely involves both genetic and environmental factors.

What is the life expectancy of IgA nephropathy?

Recent research has found that IgA nephropathy can decrease a person’s lifespan by about 10 years.

What are the common symptoms of IgA nephropathy?

People with IgA nephropathy typically have persistent visible blood in their urine. Some people may not have symptoms. As the disease progresses, it may cause kidney damage, which can result in symptoms of pain and swelling, among others.

Is IgA nephropathy life threatening?

For many people, IgA nephropathy progresses slowly. Some people may also develop kidney failure and other life threatening complications.

IgA nephropathy is a chronic kidney disease that occurs when immunoglobulin A builds up in the kidneys. The condition affects each person differently, and treatment can help slow the progress.