Your immune system does its best to protect you from infections with bacteria and viruses, but sometimes it makes mistakes. Immunoglobulin A nephropathy (IgAN) is one example of what happens when your immune system ends up doing more harm than good. This kidney disease is caused by collections of proteins known as antibodies that form in the kidneys, leading to inflammation and damage.

In this article, we’ll cover what IgAN is, what causes it, and what symptoms to look out for. We’ll also go over how your doctor or nephrologist (a physician specializing in kidney diseases) diagnoses it.

The sooner you receive a diagnosis and begin treatment, the better your chances of preventing chronic kidney disease, end-stage renal disease, or even kidney failure. Here are some facts you should know about IgAN.

1. IgA Nephropathy Affects How Your Kidneys Function

IgA nephropathy — or Berger’s disease — affects your kidneys’ small filtering units, known as glomeruli. Your kidneys are responsible for filtering extra water and waste out of your blood. When your kidneys are damaged, they leak protein and blood into your urine.

IgAN is a glomerular disease that can progress over time. Long-term kidney damage can eventually lead to scarring. If it’s left untreated, you may eventually develop end-stage kidney disease. Each case is different. For some people, this progress can happen quickly. For others, it takes decades.

2. IgA Nephropathy Is Considered an Autoimmune Disease

To better understand what causes IgAN, it helps to first learn about antibodies. Your immune system makes five types of antibodies to protect you from getting sick. These proteins, or immunoglobulins, are found throughout your body to stop bacteria and viruses from taking hold.

IgA antibodies are located in your bloodstream and the tissues that line your mouth, nose, throat, and digestive tract. They help protect you from tiny organisms like bacteria and viruses in the air you breathe and the food you eat.

Doctors and researchers aren’t quite sure what causes IgAN, but they believe it’s an autoimmune disease. This means that your immune system starts attacking your body’s cells and proteins. If you have IgAN, your body produces IgA antibodies that are low in galactose, a type of sugar. Your immune system thinks these abnormal antibodies are foreign invaders, and it makes other antibodies to attack them.

When antibodies attach to each other, they form clumps or immune complexes. These complexes travel through your blood, which is filtered by your kidneys. When the clumps try to pass through the glomeruli, they get stuck. This creates inflammation that damages the glomeruli, eventually leading to IgAN.

3. Age, Race, Sex, and Genetics Can Play Roles in IgA Nephropathy

According to the National Institute of Diabetes and Digestive and Kidney Diseases, certain risk factors increase your chances of IgAN. People with a family history of this disease are more likely to develop it. Certain gene changes passed down through family members may play a role.

Your age, race, and sex also affect your risk. IgAN tends to first appear in teenagers and adults in their late 30s. According to Cleveland Clinic, it’s also more common in European and Asian people. Twice as many men as women have it in the U.S. In addition, health conditions, including HIV, liver disease, and celiac disease, are associated with IgAN.

4. Symptoms Tend To Occur When the Disease Progresses

Most people with IgAN don’t experience symptoms until the disease has progressed. It develops slowly over many years, so it can take time for you to notice any changes. Common symptoms of IgAN include:

• Foamy urine — This is a sign of proteinuria (protein in your urine) caused by leaky filtering units in your kidneys.
• Red or dark urine that looks like cola — This indicates hematuria (blood in urine). In some cases, your urine may contain tiny amounts of red blood cells that can’t be seen without a microscope.
• Hypertension (high blood pressure) — Your kidneys can’t filter out water and fluid properly, so your body holds on to it, raising your blood pressure.
• Edema (swelling) — Extra fluid can collect in your hands and feet, making them puffy or swollen.
• Flank pain — You experience pain between your stomach and back where your kidneys are located.

5. Urine and Blood Tests May Be Used To Diagnose IgAN

Your doctor will diagnose IgAN using information collected from your medical history, family history, physical exam, and various tests. They’ll talk with you about your symptoms and other health conditions, and they’ll ask if anyone in your family has IgAN or another kidney disease.

Your care team will measure your blood pressure and other vital signs. They’ll also check your hands and feet for swelling. Be sure to let your doctor know about any changes in your urine or pain in your sides or back.

Blood and urine tests can tell your doctor a lot about how well your kidneys are working. Your estimated glomerular filtration rate (eGRF) is measured with a blood test, which tells your doctor how much blood your kidneys filter over one minute. A normal eGRF result for adults is about 100, but it gets lower with age. If the number stays under 60 for at least three months, you may have chronic kidney disease (CKD).

You’ll likely give a urine sample to be tested for blood and protein. Sometimes, blood in urine can be seen only by these tests. A special piece of paper with chemicals, known as a dipstick, is placed into the sample and changes color depending on how much blood is in your urine. A dipstick test can also measure urine protein levels. You may have to give just one sample or multiple samples over 24 hours.

In some cases, your doctor may order a kidney biopsy. They’ll use a long, thin needle to remove a piece of kidney tissue to look at under a microscope. A specialist, known as a pathologist, will look for IgA deposits, inflammation, and damage.

6. Treatment Involves Medication and Lifestyle Changes

If you’ve noticed any new signs of IgAN, talk to your primary healthcare provider or a nephrologist. They can run tests that may lead to a diagnosis. It’s important to start a treatment plan soon after diagnosis to maintain good kidney function. Treatment options your doctor may prescribe include:

• Medications to lower blood pressure and urinary protein
• Corticosteroids or immune system treatments to reduce inflammation
• Lifestyle changes, like a low-sodium diet
• Statins to lower cholesterol levels
• Diuretics to help your body clear out extra water

Some people with IgAN eventually develop kidney failure. In this case, the treatment options are dialysis or a kidney transplant. However, monitoring your condition carefully and staying on track with your treatment plan can help you stay healthy, as well as reduce your risk of complications and other health problems.

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On myIgANteam, people share their experiences with IgA nephropathy, get advice, and find support from others who understand.

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