IgA nephropathy affects your kidneys’ ability to filter your blood. It happens when a protein called immunoglobulin A (IgA) builds up in your kidneys over time and inflames them. This protein normally helps your body fight infections. So IgA nephropathy is both a kidney disease and a disease of your immune system.
It isn’t clear why people get IgA nephropathy. But it happens more often in men and in people of certain racial or ethnic backgrounds. It’s also more common in some parts of the world than it is in others. It isn’t clear why there are such differences in IgA nephropathy. It’s likely there are many complex factors involved.
IgA nephropathy not only happens more in some places than others, but it also looks different in different places. The disease can show big differences from one person to the next in:
- Progression
- Complications
- Treatment response
These differences also can be related to differences in geography, race, ethnicity, and sex in complicated ways. More study is needed to understand variation and disparities in IgA nephropathy and their root causes.
Who Gets IgA Nephropathy?
IgA nephropathy is more likely in:
Certain racial or ethnic groups. People who are Asian, White, or Native American (in the Zuni or Navajo tribe) get it more often. While Black people are at more risk of kidney diseases than other groups in general, they don’t get IgA nephropathy as often.
Men or people who were identified as a male at birth. Most studies show that men get the disease at least twice as often as women. Some suggest it may even be six times more likely in people identified as males at birth.
Certain families. This is likely because of certain genes that are passed down from one generation to the next.
Looking Deeper into Disparities in IgA Nephropathy
How common IgA nephropathy is also depends on the country you live in. In the U.S., about 10% of people who get a biopsy for a disease that affects your kidneys’ ability to filter your blood will find out they have this condition. Doctors diagnose it more often in Asian countries, compared to the U.S.
But it’s not clear how much differences in diagnosis reflect true differences in the actual number of cases of the disease. It’s possible that kidney specialists (nephrologists) in the U.S. don’t order kidney biopsies as often for people who don’t have symptoms when tests of their pee show only minor changes. So the condition might not get diagnosed even when it’s there.
In Asia, doctors often order pee tests as part of regular checkups. They also routinely order kidney biopsies based on pee test results even when there aren’t any symptoms. Experts think this could be one reason why the number of cases looks higher in some parts of the world. More people in the U.S. may have this disease and not know it.
Whatever the reason, around the world, you can see big differences. In Asia, 40% of kidney biopsies in people with signs of kidney trouble show IgA nephropathy. That’s compared to 20% in Europe and 10% in North America.
IgA nephropathy is especially common in:
- Singapore
- Japan
- Australia
- Hong Kong
- Finland
- Southern Europe
The disease is less common in:
- The United Kingdom
- Canada
- The United States
A Closer Look at IgA Nephropathy Cases and Disparities
Other things may affect the number of cases, too. For example, one study in Scotland found that people who lived in areas with fewer resources had it twice as often. The differences couldn’t be explained by differences in the ages or backgrounds (demographics) of the people living there.
While it’s hard to separate differences in diagnosis from real differences in the disease, there may be complicated reasons people with different ancestries have IgA nephropathy more. For example, it happens more in places where people more often get infected with certain parasitic worms. Most of the genes that have been linked to IgA nephropathy also may affect internal structures in the body that help to protect against these parasites. So it’s possible that people with genetic changes that protect against parasites also have more risk of IgA nephropathy.
More study is needed
It’s hard to tell if there are really big differences in IgA nephropathy based on race because of limited data. It’s possible that certain groups get it more often based on genes they more often carry. A person’s race also may affect how likely it is a doctor will order a kidney biopsy.
Most studies don’t include Black people in them as much as White people. Most studies of the disease also have been done in countries that don’t have a lot of diversity. And doctors don’t know how often IgA nephropathy affects people from South America or Latino people living in the U.S. That’s because studies in those groups are lacking.
One report looked at all the data in 16 studies. Overall, the report found IgA nephropathy is diagnosed very rarely in South Africa and a lot more in Japan. It also seems more common in people who are Asian than in other groups. But five studies in the U.S. didn’t find any clear or consistent differences between Black and White people. The researchers concluded that more study is needed to really understand differences among groups concerning this disease and their causes.
Is IgA nephropathy more than one disease?
It’s possible. IgA nephropathy is a leading reason people have chronic kidney disease. It also can lead to kidney failure. Though you can’t cure it, medicines can help keep it from getting worse. But because of the way this disease is diagnosed, doctors aren’t even sure if it’s really one disease. It could be that it’s a pattern of changes in the kidney that can happen for different reasons. So the reason it looks so different in different groups or parts of the world – and the reason some groups have different outcomes – could be that it really isn’t one disease.
What Are Gender Disparities in IgA Nephropathy?
Men get IgA nephropathy more often overall for reasons that aren’t clear. There’s some evidence they may also get worse faster, but experts aren’t sure. That’s because studies in different places have had different results. For instance, studies in China showed no difference in long-term survival between men and women. But a study from Estonia found that men got worse faster.
IgA Nephropathy and Racial/Ethnic Disparities in Health Care Overall
IgA nephropathy makes it harder for your kidneys to do their job of filtering your blood. Many times, it gets worse slowly over years. You might see blood in your pee without noticing anything else. Or you could have it without noticing any symptoms at all.
Medicines can help to slow it down, so your access to doctors and health care will affect how you’ll do with IgA nephropathy. Your access to doctors and good health care also will affect how likely it is you’ll get diagnosed. Overall, people who belong to minority racial or ethnic groups tend to get worse care and outcomes across the board.
Doctors know there are big disparities in health care use and access based on a person’s race, ethnicity, and gender. These disparities will affect the diagnosis and treatment of IgA nephropathy and other conditions. People in minority groups in the U.S. are more likely to:
- Lack a usual doctor or clinic they go to for care
- See doctors less often
- Spend less on health care
These differences happen for many reasons, including differences among groups in:
- Socioeconomic status
- Health insurance
- Culture
- Language barriers
- Discrimination
One study looked at differences in health care use and access after the Affordable Care Act expanded health insurance in the U.S., compared to before. It showed that non-Hispanic White people started using health care more after the change, compared to other groups. Asian men also went to see the doctor more in 2014 than they did in 2006. By comparison, Black men and women didn’t show as much change in health care use and access in general. These general disparities in health care will affect disparities in IgA nephropathy just as they do for a person’s health in general.
What Can You Do?
Efforts are being made to reduce systematic health care disparities based on race or ethnicity. It also helps if you advocate for yourself. In the U.S., there are also health disparities based on gender. Men are generally at more risk of dying, compared to women. This may be related to cultural norms and beliefs about gender roles and other things that affect health habits and care.
If you have IgA nephropathy and are worried about your care, or if you think you may be at risk of getting this condition, it may help to:
- Learn as much as you can about the disease.
- Find a doctor you trust who will listen to you.
- Ask questions.
- Ask about assistance programs if you are worried about your finances.
If you have this disease or think you may be at risk, it’s a good idea to take steps to eat healthy and exercise.
Show Sources
Photo Credit: Moment/Getty Images
SOURCES:
National Kidney Foundation: “Race, Ethnicity, & Kidney Disease.”
Medscape: “IgA Nephropathy.”
Nephrology: “Is immunoglobulin A nephropathy different in different ethnic populations?”
Kidney 360: “Global Incidence of IgA Nephropathy by Race and Ethnicity: A Systematic Review,” “The Phenotypic Difference of IgA Nephropathy and its Race/Gender-dependent Molecular Mechanisms.”
Mayo Clinic: “IgA nephropathy (Berger disease).”
American Medical Association: “Reducing disparities in health care. ”
Health Services Research: “Racial/Ethnic and Gender Disparities in Health Care Use and Access.”
KFF.org: “Eliminating Racial/Ethnic Disparities in Health Care: What are the Options?”
American Journal of Men’s Health: “Associations Between Masculine Norms and Health-Care Utilization in Highly Religious, Heterosexual Men.”
Renal Failure: “Association between lifestyle, gender and risk for developing end-stage renal failure in IgA nephropathy: a case-control study within 10 years.”
