Primary biliary cirrhosis
Primary biliary cirrhosis (PBC) is a long-term liver disease that damages the small bile ducts in the liver. The build-up of bile damages the liver.
Primary biliary cirrhosis (PBC) is a long-term liver disease that damages the small bile ducts in the liver.
This gradually leads to a build-up of bile in the liver, which then damages the organ.
Symptoms of PBC often include:
- fatigue (extreme tiredness)
- itchiness of the skin
- dry eyes and mouth
Read more about the symptoms of PBC.
Bile and bile ducts
Bile is a liquid produced inside the liver that is used by the digestive system to help digest fats and remove waste from the body. It is transported out of the liver into the small bowel through a series of small tubes called bile ducts.
In PBC, for reasons not fully understood, the immune system (the body's natural defence against infection and illness) gradually damages the bile ducts. Eventually, the damage leads to a blockage that obstructs the flow of bile. The amount of bile in the liver builds up to a dangerous level, causing scarring (cirrhosis).
Who is affected?
PBC is a rare liver condition. In England and Wales, PBC is estimated to affect one in every 3,000 people. However, the rates of PBC in England are higher than in some other parts of the world. The reason for this is unknown.
PBC mainly affects women (about 90% of all cases). The condition usually occurs in people aged 30-65, and is normally diagnosed after a person has reached 40.
The exact causes of PBC, and why it mainly affects women, are unknown.
Read more about the causes of PBC.
PBC is usually a progressive condition, which means damage to the liver can steadily get worse over time. The rate at which PBC progresses varies between individuals. It can take decades in many cases.
If not treated, the liver can become damaged to such an extent it no longer works. This is known as liver failure and can be fatal.
There is no cure for PBC, but there are medicines that help slow the progression of the condition and that help relieve the itchiness associated with it. In cases where there is extensive liver damage, a liver transplant may be required.
However, over the last 20 years, the need for liver transplants as a result of PBC has been decreasing. This may be due to the use of a medicine called ursodeoxycholic acid (UDCA).
Read more about how PBC is treated.
Primary biliary cirrhosis
The exact cause of primary biliary cirrhosis (PBC) is unknown, although it is thought that a combination of genetic and environmental factors may play a part.
The exact cause of primary biliary cirrhosis (PBC) is unknown, although it is thought a combination of genetic and environmental factors may play a part.
These are described below.
- genetic factors – the genes that you inherit make you susceptible to developing PBC
- environmental factors – something in the environment triggers PBC (see possible triggers, below)
Most experts believe that PBC is an autoimmune condition. In these types of conditions, something goes wrong with the immune system (the body's natural defence against infection and illness). Instead of fighting off infection, the immune system attacks healthy tissue. It is not known what causes the immune system to malfunction and attack the bile ducts.
In cases of PBC, the immune system sends specialised cells, known as T-cells, to the site of the bile ducts. T-cells usually kill bacteria and viruses.
The T-cells start to damage the surface of the bile ducts, which gradually become extensively scarred and disrupt the usual flow of bile. As the amount of bile in the liver increases, further scarring of the liver (cirrhosis) occurs.
Over time, high levels of cirrhosis cause the liver to lose some, and eventually all, of its function. As the liver plays a vital role in filtering out impurities from your blood, a loss of liver function is potentially fatal.
Other autoimmune conditions
Having one autoimmune condition such as PBC can make it more likely you will have other autoimmune conditions. For example, people with PBC may also have:
- autoimmune thyroid disease – a condition that affects the thyroid gland in your neck, which produces hormones
- an underactive thyroid (hypothyroidism) – a type of thyroid condition where the thyroid gland does not produce enough hormones; around a fifth of people with PBC also have an underactive thyroid gland, which may be responsible for the fatigue
- rheumatoid arthritis – a condition that causes pain and swelling in the joints
- scleroderma – a condition that affects the connective tissue (the supporting tissues of the body), causing hard, puffy and itchy skin
- autoimmune hepatitis – a very rare cause of chronic (long-term) hepatitis, where the white blood cells attack the liver
- Sjogren's syndrome – a disorder where the white blood cells attack the body's tear and saliva glands
- Raynaud's phenomenon – a common condition of the blood vessels that supply blood to the skin, causing them to narrow and reduce blood flow to the hands
- coeliac disease – a common digestive condition where a person is intolerant (has an adverse reaction) to the protein gluten
There is some evidence to suggest that certain things increase your chances of developing PBC. These risk factors are explained below.
PBC occurs mostly in women. Less than one in 10 cases of PBC occur in men.
One theory for this is that the immune system is upset by the female sex hormone, oestrogen.
Having a close relative with PBC means you are more likely to develop the condition yourself. For example, if you are female and your mother has or has had PBC, you are much more likely to develop PBC than someone who has no relatives with the condition. However, the risk is still low. More than 99% of people who have a first-degree relative with PBC will not develop the condition themselves.
This family connection has led researchers to speculate that certain genes (units of genetic material) inherited from your parents may make you more likely to develop PBC.
Certain things may trigger PBC in people with a genetic tendency. These include:
- infections, such as a urinary tract infection (UTI)
- hormone replacement therapy (HRT) – a treatment used to replace the female hormones that a woman's body no longer produces because of the menopause
- using nail varnish or cosmetics
- smoking cigarettes or having a past history of heavy smoking
- living near to where toxic waste has been dumped
However, none of these have been proven as definite triggers of PBC. Most people who are exposed to them will not develop the condition. At present, there is nothing to suggest you should reduce your exposure to these triggers to lower your risk of developing PBC.
Primary biliary cirrhosis
Although there is currently no cure for primary biliary cirrhosis (PBC) treatments are available to relieve symptoms and prevent liver damage.
There is currently no cure for primary biliary cirrhosis (PBC), so the aim of treatment is to prevent liver damage as much as possible and relieve symptoms, such as itchiness.
All types of liver disease, including PBC, can be helped by following some general health advice. You should:
- quit smoking (if you smoke)
- avoid obesity by maintaining a healthy weight
- not drink more than the recommended daily limits of alcohol (3-4 units a day for men, and 2-3 units a day for women)
Not following this advice could speed up the progression of your condition. It may also affect whether or not you can have a liver transplant, if you need one. For example, you may not be offered a liver transplant if you misuse alcohol.
Ursodeoxycholic acid (UDCA) is a widely used treatment for people with PBC. UDCA is thought to help prevent liver damage by changing the composition of the bile and reducing inflammation (swelling) of the liver. Studies have shown that UDCA can:
- reduce the levels of liver enzymes – these proteins are produced by the liver if the bile ducts and liver are damaged
- reduce the need for a liver transplant
UDCA is thought to work better in the early stages of PBC and is not effective for everyone.
UDCA is usually taken as a single dose at night. It does not improve the other symptoms of PBC, such as itchy skin or fatigue (extreme tiredness).
Once you start taking UDCA, it is likely you will need to take it for the rest of your life. Your liver function may be tested to monitor your condition and you will be assessed after a year to see if you need additional treatment. If you are responding well, it is likely the PBC will remain under control and will not shorten your life span.
One possible side effect of UDCA is weight gain. People gain an average of 2.3kg (5lbs) during the first year of taking the medication. After this initial weight gain, most people do not gain any more weight from the drug. Other side effects include:
- loose stools
- thinning hair
- nausea (feeling sick)
PBC sometimes occurs alongside autoimmune hepatitis. This is a very rare cause of chronic (long-term) hepatitis, where the white blood cells attack the liver.
If you have autoimmune hepatitis, you may be treated with corticosteroids as well as UDCA. Corticosteroids are medicines that contain steroids, a type of hormone. They work by suppressing your immune system (the body's natural defence system) and reducing inflammation.
You will usually be treated with a type of corticosteroid called prednisolone. For more information, see the British Liver Trust: autoimmune hepatitis.
Colestyramine, which used to be called cholestyramine, is a medicine widely used to treat the itchiness associated with PBC.
Colestyramine reduces the amount of bile in the blood, which is thought to be the main cause of the itchiness. It usually comes in sachets of a powder that can be dissolved in water or fruit juice. It is a good idea to take the powder with fruit juice, because it has an unpleasant taste.
You may need to take colestyramine for several days before your symptoms begin to improve.
If you are taking UDCA as well as colestyramine, you should avoid taking them at the same time because colestyramine will affect how your body absorbs UDCA. You may need to take UDCA at least one hour before colestyramine, or four to six hours afterwards.
This also applies to any other medicines you are taking. Take them at least one hour before colestyramine, or four to six hours afterwards. Your GP should be able to give you further advice about this.
Constipation is a common side effect of colestyramine. This usually improves once your body gets used to the medicine. Other side effects of colestyramine include:
If you are taking colestyramine on a long-term basis, the medicine may affect your body's ability to absorb vitamins A, D and K from food. In such circumstances, taking additional vitamin supplements may prove beneficial. Your GP can advise you about whether you would benefit from taking vitamin supplements.
Alternative medicines for itching
See your GP if your itchiness does not improve after taking colestyramine. Alternative medicines are available.
For example, rifampicin, which is usually used as an antibiotic, has been used to treat itching in some people. However, it can cause serious side effects, such as liver failure. For this reason, rifampicin is usually only prescribed by a specialist, such as a hepatologist (liver specialist), not your GP.
It is thought that the female hormone oestrogen may make itching worse. Oestrogen is found in some types of hormonal contraceptives, such as the combined contraceptive pill. Therefore, you may wish to consider using a different type of contraceptive, such as condoms.
Oestrogen levels are also increased during pregnancy, so your itching may be worse when you are pregnant.
At the moment, no medicines are specifically recommended for treating the fatigue caused by PBC. Your GP may rule out other causes for your fatigue, such as anaemia (a lack of red blood cells) or depression, but fatigue is a difficult symptom to treat.
Although you should exercise whenever possible, you may need to pace yourself and limit your daily activities to a manageable level in order to cope with your fatigue.
A liver transplant may be recommended if it is thought that the liver damage may reach the stage where your life is at risk.
Planning for a liver transplant often begins before significant damage to the liver has taken place. There are two reasons for this:
- the average waiting time for a liver transplant is 142 days, so it is important to start searching for a suitable donor as soon as possible
- the better your general state of health, the greater the chance of a successful transplant, so a transplant should ideally be carried out while you are still relatively healthy
Like all organ transplants, liver transplants carry the risk of complications. The most serious complication is that your immune system may reject the donated liver, which could be fatal. You may need to take immunosuppressants (medicine to suppress your immune system) for the rest of your life.
The success rates of liver transplants for people with PBC are favourable. For example, one study of 121 people who had a liver transplant for PBC found that:
- 90% were still alive after five years
- 87% were still alive after 10 years
- 80% were still alive after 15 years
In this study, PBC recurred in 15% of people, although some estimates suggest that the condition may recur in up to a quarter of people after a liver transplant.
The itchiness always improves after having a liver transplant, but the fatigue often does not improve.