Rheumatoid arthritis (RA) is an autoimmune disease that can be associated with primary biliary cholangitis (PBC). RA and PBC are both autoimmune diseases that usually affect different parts of the body. RA mainly affects your joints, and PBC affects the small bile ducts in your liver.

RA affects about 5 percent to 10 percent of people with PBC. Additionally, people with RA may have an increased risk of also developing PBC. Even though RA typically only involves your joints, it may also affect your liver. Continue reading to learn more about how RA can affect how your liver works.

What Is Rheumatoid Arthritis?

Before we dive into how RA can affect your liver, let’s learn more about RA.

Although RA and PBC are both autoimmune conditions, the immune system attacks different parts of the body in each of these diseases. PBC is an autoimmune liver disease that develops when the immune system attacks the small bile ducts of the liver. This attack causes inflammation, scar tissue, and liver damage.

RA is an autoimmune disease that happens when the immune system mistakenly attacks healthy tissue in the joints. When the immune system attacks the joints, it results in joint inflammation that causes pain, swelling, and stiffness in affected joints.

While joint inflammation and pain are the main symptoms of RA, this disease can also attack other parts of the body, such as the skin, heart, and lungs. Liver involvement isn’t usually recognized as a clinical feature of RA. However, significant liver problems can develop when someone has both RA and PBC.

How Common Is RA in People With PBC?

RA and PBC are relatively rare conditions. According to an article in the Journal of Clinical Medicine, about 1.3 million people in the United States are living with RA — that’s less than 1 percent of the adult population. Even fewer people have PBC, and most of them are women or people assigned female at birth. The American Liver Foundation estimates that about 65 out of every 100,000 women in the U.S. have PBC, which amounts to less than 110,000 American women in 2022, for example.

Although both RA and PBC are rare, it’s reported that between 5 percent and 10 percent of people with PBC also have RA. This means that the prevalence (portion of a population) of RA is higher in people with PBC compared to the general population.

Additionally, people who have RA may also have an increased risk of developing PBC. About 4 percent to 6 percent of people with RA develop an autoimmune liver disease, like PBC. In most cases of people with RA and PBC, people develop RA first.

What’s the Connection Between RA and PBC?

Researchers are still studying the connection between RA and PBC. Apart from both being autoimmune conditions, RA and PBC affect similar populations of people.

Cleveland Clinic has found that RA is about 2.5 times more common in women compared to men. Similarly, PBC affects mostly women, who are about nine times more likely to be diagnosed with PBC compared to men.

While either condition can develop in people of any age, most people with RA or PBC are diagnosed in middle age. RA is typically diagnosed between the ages of 30 and 60, whereas PBC most often affects people aged 45 to 65 years.

Genetics may play a role in why people with PBC may be more likely to also have RA. Genetic studies have found that some of the same genes are involved in the development of RA and PBC. Some research from the journal Arthritis also suggests that an infection may trigger RA or PBC in people with genes that make them prone to developing the disease. However, more studies are needed to find out if there is a genetic link between RA and PBC.

How Does RA Affect Your Liver?

If you’re living with PBC, it’s important to understand how other diseases and medications may affect your liver. Apart from having both PBC and RA, there can be other reasons for abnormal liver test results in people with RA.

Doctors can find liver problems related to RA by looking at liver function tests. These blood tests measure different substances made by your liver.

Up to half of people with RA have been found to have higher-than-normal levels of alkaline phosphatase — a liver enzyme (protein) that’s elevated with liver injury. Most of the time, these abnormal liver test results are not linked to a specific cause and are temporary. Usually, no treatment is needed other than managing the RA and checking for other possible liver diseases.

Examining a small piece of liver tissue (called a liver biopsy) can also reveal liver problems associated with RA. Studies from the journal Arthritis Research & Therapy have found that about 2 out of 3 people with RA who had a liver biopsy had abnormal liver tissue. Of those with an abnormal liver biopsy result, about half had inflammation in the bile ducts and blood vessels in the liver, and 1 in 4 had fatty liver disease.

RA Treatment and Liver Function

RA treatment can help relieve your joint pain and slow down the progression of RA. Treatment for RA may include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) to improve pain and inflammation
• Corticosteroids to decrease inflammation
• Disease-modifying antirheumatic drugs (DMARDs) that slow the RA disease process by reducing inflammation
• Biologics (drugs ​​made from living cells) that decrease inflammation by targeting inflammatory substances in your joints

Although RA treatments can greatly improve the outlook of people living with RA, they can also cause liver-related side effects. The RA treatments most likely to cause liver damage are NSAIDs and methotrexate (Trexall), a DMARD. Newer biologic RA treatments are less likely to cause liver damage.

Talk to Your Health Care Provider

If you’re living with PBC, it’s important to be aware of how medical conditions and medications can affect your liver. Talk to your health care provider about your risk of being diagnosed with RA. If you have PBC, you may already have some risk factors, such as being a woman or assigned female at birth and being middle-aged. You may have an increased risk of RA if you also have a close family member with RA, have obesity, or smoke.

If you’re living with RA, talk to your health care provider about your risk of developing PBC. If your liver function test results are abnormal, your provider may check for PBC by testing for antimitochondrial antibodies, which are proteins that mistakenly attack your body’s cells. They may also perform a liver biopsy to get more information.

If you’re living with both RA and PBC, talk to your health care provider about how your liver function will be monitored. They may suggest treatment options for RA that are less likely to cause liver damage, such as biologics. You can also talk about treatment options for common side effects of both RA and PBC, such as fatigue (extreme tiredness).

You and your health care provider can develop a plan to manage both RA and PBC so you can be your healthiest, feel your best, and improve your quality of life.

Find Your Team

On myPBCteam, the social network for people with primary biliary cholangitis and their loved ones, members come together to ask questions, give advice, and share their tips with others who understand life with PBC.

Are you living with RA and PBC? Has RA affected your liver function? How have you managed both conditions? Share your experience in the comments below, or start a conversation by posting on your Activities page.