Causes and Risk Factors of IgA Nephropathy

Doctors do not know exactly what causes IgA nephropathy, but research has taught us a lot about how it develops and who is most likely to get it. Understanding these factors can help you make sense of your own diagnosis.^1-3

What happens in IgA nephropathy

IgA nephropathy is considered an autoimmune disease. That means the immune system, which normally fights germs, ends up harming the body’s own kidneys.^2,3

Immunoglobulin A (IgA) is an antibody your immune system makes. In IgA nephropathy, the body produces a slightly different form of IgA. The immune system treats this IgA as a foreign invader, so other antibodies attach to it and form clumps. These clumps get stuck in the glomeruli, the tiny filters in your kidneys. This causes inflammation, and over time, it leads to scarring that makes it harder for your kidneys to filter your blood.³

What can trigger symptoms?

For many people, the first signs of IgA nephropathy appear after an infection, especially a respiratory or bowel infection. More IgA circulates in the body during a cold or an upper respiratory infection, and some of it can end up in the kidneys. This is why some people notice cola-colored (very dark colored) urine during or right after being sick.^1,3

It is important to know that the infection does not cause the disease. It simply brings the existing condition to the surface.

Who is more likely to get IgA nephropathy?

IgA nephropathy can affect anyone at any age. But some factors make it more likely:^1,2,3

• Sex – In the United States, IgA nephropathy affects about twice as many men as women.
• Age – The first signs usually appear between the late teens and the late 30s, though it can develop at any age.
• Ancestry – It is more common in people of Asian or European descent and less common in Black people.
• Family history – IgA nephropathy and a related condition called IgA vasculitis can run in families. Researchers have found genes that may raise the risk.
• Other health conditions – It is more common in people who have certain conditions, such as celiac disease, liver diseases like cirrhosis and hepatitis, and infections such as HIV.

Can IgA nephropathy be prevented?

There is no known way to prevent IgA nephropathy. Researchers have not found that diet or any specific habit causes or prevents it.^1,3

If IgA nephropathy runs in your family, talk to your doctor. They can suggest steps to keep your kidneys as healthy as possible, such as keeping your blood pressure and cholesterol in a healthy range.^2,3

Talk to your doctor

Learning what causes IgA nephropathy can leave you with questions about your own risk, especially if a family member has it. Your doctor can talk with you about your personal and family health history and what it may mean for you. If you notice that your urine is frothy (excessive bubbles) or there is blood in it, see your doctor so the cause can be checked.^1,2