Primary biliary cholangitis (PBC) is a chronic (long-lasting) liver disease that can significantly affect a person’s life. But is PBC an autoimmune disease? Researchers believe it is, and that’s important for understanding how PBC develops and how it affects the body.

This article will cover the basics of PBC (previously known as “primary biliary cirrhosis”) and how it progresses. We’ll also discuss the autoimmune characteristics of PBC — specifically, how the body’s immune system attacks its own bile ducts by mistake — and ways that PBC affects the health of people living with this condition.

What Is Primary Biliary Cholangitis?

Primary biliary cholangitis is a disease that affects the liver, causing damage over time. This important organ is located in the upper right side of your abdomen. Your liver helps filter harmful substances from blood and produces bile, a fluid that helps digest and absorb fats in the small intestines.

In PBC, small tubes in the liver called bile ducts become inflamed and damaged. Bile can’t properly flow out of the liver, and the buildup harms the liver cells. Over time, this ongoing damage can lead to advanced, permanent scarring of the liver, a condition known as cirrhosis.

PBC progresses slowly, with damage to the bile ducts and liver cells happening over many years. If the liver becomes very scarred, it can lead to more serious problems like liver failure. Understanding how PBC develops and gets worse is important for managing the disease and finding ways to slow down liver damage.

What Causes Primary Biliary Cholangitis?

Scientists are still trying to figure out just what causes primary biliary cholangitis . They believe the condition is the result of a combination of genetic and environmental factors. Some people might have genes that make them more likely to get PBC. Then, something in the environment, like certain infections or toxins, might trigger the disease.

What Are the Symptoms of Primary Biliary Cholangitis?

In the early stages, PBC might not cause any noticeable symptoms. About half of people don’t have any symptoms at first. As the disease progresses, the most common symptoms include:

• Fatigue
• Itchy skin
• Dry eyes and mouth

Some people may also have pain in the upper right side of the abdomen.

As the liver becomes more damaged, symptoms can become more severe and may include:

• Jaundice (yellowing of the skin and eyes)
• Swelling in the legs and abdomen
• Darkening of the skin

These symptoms show that the liver is having a hard time functioning properly.

Can Primary Biliary Cholangitis Be Prevented?

Currently, there’s no known way to prevent PBC because its exact cause is not fully understood. However, detecting and treating it early can help manage symptoms and slow progression of the disease. Regular checkups and monitoring of liver function are important for people at risk of PBC or those who have been diagnosed with the condition.

Understanding Autoimmune Diseases

To understand whether PBC is an autoimmune disease, it’s important to first know what the immune system is. The immune system is the body’s defense system. It’s made up of many parts, including proteins, cells, and organs, that help protect the body from germs like bacteria and viruses.

An autoimmune disease occurs when your immune system, which normally fights off germs to keep you healthy, mistakenly attacks your own cells. Scientists have found more than 80 autoimmune diseases, each affecting the body in different ways. Some of the more common autoimmune diseases include type 1 diabetes and rheumatoid arthritis.

How Autoimmune Diseases Affect the Body

When you have an autoimmune disease, your body makes autoantibodies that can be detected with a blood test. The immune system produces these special proteins to target and attack healthy cells. These autoantibodies are different from antibodies, which are proteins that the immune system normally makes to fight off harmful invaders like bacteria and viruses.

The attack on healthy cells causes the affected area to become discolored, swollen, and painful, which is called inflammation. This inflammation can happen in different parts of the body. For example, an immune system attack on the joints might cause joint pain and stiffness, which is known as arthritis.

Other symptoms of autoimmune diseases depend on which part of the body is affected. Symptoms of autoimmune diseases can come and go, and other illnesses can cause similar symptoms.

Primary Biliary Cholangitis and Autoimmunity

More than 95 percent of people with PBC have certain autoantibodies in their blood. These autoantibodies — known as “antimitochondrial antibodies” — attack the body’s mitochondria, which are tiny structures that produce energy in cells. However, these autoantibodies don’t destroy the bile ducts. Instead, other immune cells attack the bile ducts, causing inflammation.

Because of these immune system abnormalities, researchers believe that PBC may be an autoimmune disease. However, there’s still much that scientists don’t know about what causes PBC, and research is ongoing.

Since the immune system mistakenly attacks the bile ducts, current treatment strategies for PBC focus on holding back the immune system and promoting the flow of bile. Doing so can help slow down liver damage and prevent the need for a liver transplant. Additionally, health care providers may recommend over-the-counter medicines or prescribe treatments to manage symptoms like itchy skin.

By recognizing PBC as an autoimmune disease, health care providers can tailor treatment plans to target the immune system’s role in the disease. This understanding can also guide researchers in developing treatments that may offer even better results. For example, future treatments might aim to reduce the immune system’s attack on the bile ducts, protecting the liver from inflammation and damage.

PBC and Other Autoimmune Diseases

Research has shown that PBC commonly occurs with other autoimmune diseases. Recent studies show a possible link between PBC and lupus — specifically, systemic lupus erythematosus, the most common type. Other autoimmune diseases that people may have along with PBC include:

• Autoimmune thyroid diseases
• Raynaud’s disease
• Sjögren’s syndrome
• Scleroderma
• Autoimmune hepatitis

Living with PBC often means having other chronic conditions too. It’s important to know about these connections so you can get the right treatment and support.

Find Your Team

On myPBCteam, the social network for people with primary biliary cholangitis and their loved ones, more than 1,300 members come together to ask questions, give advice, and share their tips with others who understand life with PBC.

Have you wondered if PBC is an autoimmune disease? Do you have an autoimmune disease besides PBC? Share your experiences in the comments below, or start a conversation by posting on your Activities page.