What is PBC
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What you should know about PBC
What is Primary Biliary Cholangitis (PBC)?
Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is a slowly progressive bile duct disease, which results from chronic inflammation of the small intrahepatic bile ducts, the system of small tubes in the liver that helps drain bile. It is variable and slowly progressive. The name was changed from primary biliary cirrhosis to primary biliary cholangitis as most patients do not have cirrhosis at diagnosis. For some people, though, the inflammation leads to bile duct loss and liver scarring which may, after many years to decades, affect the entire liver and lead to cirrhosis. It is thought to be caused by a person’s immune system attacking his or her own liver, but the cause is still unknown. It is likely that something in a person’s genes and/or in the environment may cause PBC, and there is a lot of ongoing research to find out the cause.
How many people are affected by PBC?
It usually affects women 35-60 years of age but it may be seen in younger women. Men also can have the disease. For every nine women affected with PBC, one man may be affected. PBC is the most common autoimmune liver disease, affecting 1 in 1,000 women over the age of 40.
What causes PBC?
At present the cause is unknown. It is not caused by alcohol or any known transmissible diseases. PBC is thought to have an autoimmune basis, probably triggered by an environmental factor in a person with a subtle genetic predisposition. Smoking appears to be a risk factor.
Researcher have identified genes that are associated with the development of PBC. These genes are also implicated in related autoimmune diseases, often seen in patients and their families, e.g. celiac disease, rheumatoid arthritis, scleroderma.
Studies are being performed to assess the relevance of genes associated with PBC. However, it will take some time to understand the role of individual gene candidates. Other studies are being performed to look at the possibility of environmental triggers of PBC, such as bacteria, viruses and chemicals. No environmental agents have been confirmed to date.
What are the symptoms of PBC?
- Fatigue/tiredness – even with adequate sleep (70-80%)
- Pruritus (itching) – occurs all over the body and is not associated with a rash (50-60%)
- Xanthomata (fat deposits under the skin) – small white or yellowish bumps under the skin, especially around the eyes
Today, however, many patients (60%) are diagnosed without symptoms.
If liver disease progresses, some of the more very advanced symptoms include:
- Ascites (fluid in the abdomen)
- Gastrointestinal bleeding (vomiting blood or passing black bowel movements)
- Jaundice (yellowing of the skin or eyes)
- Easy bruising or bleeding
Diseases associated with PBC
PBC is an autoimmune disease where a person’s own immune system may attack his or her liver. Because the immune system is generally “overactive”, it is common for people with PBC or their family members to have other autoimmune diseases. Some of these include:
- Thyroid disease
- Sicca Syndrome/Sjorgrens – dry mouth, dry eyes, dry vagina and dental cavities
- Raynaud’s Disease – mottled hands that feel numb or cold in response to cold temperatures
- Rheumatoid Arthritis
- Celiac Disease
- Osteoporosis – (thin bones) is often seen and sometimes related to PBC itself, though it is also common in women without PBC.
Family doctors usually identify this disease by first noting increased alkaline phosphatase (ALP) (a liver enzyme that can be measured in the blood).
A number of diseases can cause a person’s ALP to be high, so another test is done to test whether or not PBC is the cause. This test is called the antimitochondrial antibody (AMA). This antibody is present in 95% of patients with PBC, but can also be present in 1% of people without PBC.
For most people, even if the liver tests/liver enzymes are high, the function of the liver is normal. Blood tests measuring serum bilirubin, albumin and INR (clotting time) can be used to monitor liver function.
Often patients with PBC may have increased cholesterol levels in their blood.
A liver biopsy for PBC is now rarely done. It is performed in people where the doctor thinks PBC is likely, but the AMA is negative. It is also done to make sure there are no other liver diseases present, such as other autoimmune liver diseases. A liver biopsy can tell the doctor how much inflammation and scarring is going on in the liver.
During a liver biopsy, a small sample of liver is taken using a small needle. The test is safe and does not need admission to hospital. It is performed by either a radiologist in the radiology department under ultrasound or by a hepatologist (liver specialist) in the outpatient department.
A fibroscan is a type of ultrasound that can be done in the clinic by a nurse or doctor. It does not involve radiation. The test relies on sound waves and pressure waves, and so you will feel it “knocking” on your liver while the test is done. The test only takes a few minutes to complete. It is a test that can be done to check how much scarring there is in your liver. It is just as accurate as a liver biopsy. It cannot be done on everyone, such as those with ascites, or those with very narrow rib spaces. The numbers range from >7.1 all the way to >75. If you have a fibroscan done, it is best to discuss the results with your doctor if you have any questions about it. A fibroscan is usually not done more than once a year, because liver disease progresses very slowly, so a significant change would not be expected to occur in less than a year.
How is PBC treated?
Although there is no cure for PBC at present, the majority of people have a good response to treatment. The current treatment for PBC is a synthetic bile acid, ursodeoxycholic acid (also called “urso”, “ursodiol” or UDCA), which is produced normally by everyone’s liver. People who have PBC who take UDCA may stop the progression of the disease and avoid a liver transplant. It is a medicine that needs to be taken daily to be effective. For individuals who do not respond to ursodeoxycholic acid, there is another treatment option available called obetacholic acid (OCA or Ocaliva).
What is the prognosis (expected outcome) of PBC?
For the most part, the prognosis is very good, and there are now fewer people with PBC who need a liver transplant. This is because the disease is being diagnosed earlier and treated with ursodeoxycholic acid. For many, the disease may remain silent (asymptomatic) and may never become serious. Many can lead normal lives with few symptoms for more than 20 years, or even their whole life. For the small number of people whose liver becomes severely damaged, with not only cirrhosis (severe liver scarring) but also poor liver function (that is, the complications of cirrhosis), a liver transplant may be needed. This operation is now very well established and has excellent results.
What lifestyle changes may be helpful for PBC patients?
Patients are encouraged to live a normal lifestyle. Fatigue (tiredness) is a troublesome symptom and pacing daily activities will help and preserve energy. Unfortunately, there are currently no medicines that are regularly prescribed to treat fatigue.
Your doctor is likely to recommend you lead a normal healthy life, and aim to exercise and avoid being overweight. Smoking is very bad for the liver and patients with PBC who smoke have more scarring. Alcohol usually can be consumed in moderation. Other simple advice includes taking calcium in the diet (that is, calcium-containing foods such as milk, yogurt, leafy green vegetables) and vitamin D supplements, exercising (walking, running, swimming, etc.), regular dental exams.
If you have advanced liver disease (cirrhosis), it is wise to consult with your doctor before taking any medication, including painkillers, over-the-counter medicines and/or herbal medicines or naturopathic/homeopathic substances. The liver is the body’s most important organ that metabolizes (breaks down) medicines and other substances, so any medicines must be taken with caution.
If I’ve been diagnosed with PBC, what questions should I ask my doctor about PBC?
- “How severe is the liver damage?”
- “What treatment do you recommend? Will this slow down the progression of the disease?”
- “Will any medication be prescribed? What are the side effects?”
- “Should I change my diet?”
- “Are there any supplements you would suggest that I take?”
- “What can be done to relieve my symptoms?”
- “If cirrhosis develops, is transplantation going to be needed?”
- “Is there a local hepatologist who looks after patients with PBC and who is specially trained in liver disease I should see?”
It may be advisable to have a family member or friend accompany you to help take notes and remind you what to ask.