Primary Biliary Cirrhosis
Primary Biliary Cirrhosis (PBC) is an uncommon chronic liver disease of unknown cause that slowly destroys the small bile ducts in the liver. Persisting inflammation and bile duct damage causes scarring and ultimately leads to cirrhosis.
A number of conditions are associated with PBC, particularly autoimmune diseases such as rheumatoid arthritis, Sjogren's syndrome, scleroderma, sicca complex, and thyroiditis.
Frequency in the Community: Women are affected 10 times more commonly than men. PBC is usually diagnosed in patients between the ages of 35 to 60 years.
In the early stages patients with PBC usually look quite healthy. Later the patient feels tired, develops increased tanning (pigmentation) of the skin, jaundice (yellowing of the whites of the eyes), scratch marks on the body from chronic itch (pruritus), and weight loss.
In the early stages the disease may be discovered as a result of blood tests performed for some other reason. The typical indication is a rise in the enzyme alkaline phosphatase (ALP). The other liver enzymes are usually increased but not as much as ALP. The level of serum bilirubin (bile pigment) is a useful guide to the progress of the disease. It is normal initially, slowly increasing as the disease progresses. Once the serum bilirubin level is persistently raised the patient should be followed more closely and liver transplantation should be discussed, although this may be several years away.
A liver biopsy is required to make the diagnosis and assess the stage of the disease. The liver biopsy is usually (but not always) diagnostic, and it is also important in ruling out other conditions that may mimic PBC.
Mitochondrial antibodies (also known as anti-mitochondrial antibodies or AMA) are important in making the diagnosis - a positive AMA is found in about 95% of PBC patients. Serum cholesterol, lipoproteins, and immunoglobulins may be increased.
There is no cure for PBC, but ursodeoxycholic acid (UDCA) has been shown to slow the progress of the disease and reduce the need for liver transplantation. This has been a significant advance in recent years.
Other useful therapy includes immunomodulators (for some patients who do not respond to UDCA), medications to help the itch (eg. cholestyramine, rifampicin), and vitamin and calcium supplements to counteract poor absorption of fat soluble vitamins (A, D, K, E). Osteoporosis is a major problem for some patients with PBC.
Corticosteroids (e.g. prednisolone) are not beneficial in most patients with PBC. They may sometimes be used in an 'overlap' syndrome which has both features of PBC and autoimmune chronic hepatitis, and so help some patients.
When medical treatment no longer controls the disease and the patient's symptoms are very severe or liver failure is developing, the patient should be evaluated for liver transplantation. This has been remarkably successful in patients with PBC.