Primary biliary cirrhosis (PBC) is a slowly progressive form of liver inflammation. It is so called because the liver disease starts around small bile ducts (ie it is biliary) rather than being caused by obstruction of these ducts by gallstones. In the later stages of PBC the liver may become scarred, signifying cirrhosis. But most patients have only mild scarring and do not have true cirrhosis.

Who is affected?

• PBC affects all age groups but most patients are diagnosed between the ages of 40 and 70 years. Of those affected, 90 per cent are women.
• PBC was thought to be rare but recent studies have found that it may affect up to 1 in 4000 people - and 1 in 1000 women over the age of 40.
• PBC is also slightly more common among the relatives of other patients with PBC and may be associated with smoking. It is not linked with excess alcohol consumption.

Originally, PBC was thought to affect all patients in the same way with severe itching or jaundice at the time of diagnosis and with many patients developing serious complications of their liver disease. However, these patients are now known to represent only a tiny minority of people with PBC.

Increasing use of screening blood tests means the vast majority of patients now have far milder disease at diagnosis. More than half of all patients may be completely well and without any symptoms at the time of diagnosis. These patients are usually only picked up through abnormal routine blood tests.

The two commonest symptoms seen by the remaining patients are itching and tiredness. The itching can affect any part of the body and many patients find it is worse at night. Some find it severely disrupting. Tiredness also severely affects some people but others have no symptoms at all.

Other symptoms include dry eyes or mouth, aching in the upper right part of the abdomen (over the liver) pains in the joints or bones, and red palms. Symptoms of liver failure are quite rare but include a swollen belly (ascites) or ankles, jaundice, pale faeces or vomiting blood (due to bleeding varices).

People with PBC commonly have raised cholesterol levels, which may show up as white plaques around the eyes (called xanthomata). But most patients do not need treatment to reduce their cholesterol as it is often not the form linked to heart attacks. Occasionally patients have problems absorbing certain vitamins from their diet (particularly vitamin A and D). This may be linked with thinning of the bones due to osteoporosis or osteomalacia.