Primary biliary cirrhosis

Definition

Primary biliary cirrhosis is the gradual destruction of the biliary system for unknown reasons.

Description

Although the cause of this serious condition is not known, it has many features to suggest that it is an autoimmune disease. Autoimmunity describes the process whereby the body's defense mechanisms are turned against itself. The immune system is supposed to recognize and attack only dangerous foreign invaders like germs, but many times it attacks, for no apparent reason, the cells of the body itself. Autoimmune reactions occur in many different tissues of the body, creating a great variety of diseases.

Primary biliary cirrhosis progressively destroys the system that drains bile from the liver into the intestines. Bile is a collection of waste products excreted by the liver. As the disease progresses it also scars the liver, leading to cirrhosis. In some patients, the disease destroys the liver in as little as five years. In others, it may lie dormant for a decade or more.

Causes & symptoms

Ninety percent of patients found to have this disease are women between the ages of 35 and 60. The first sign of it may be an abnormal blood test on routine examination. Itching is a common early symptom, caused by a buildup of bile in the skin. Fatigue is also common in the early stages of the disease. Later symptoms include jaundice from the accumulation of bile and specific nutritional deficiencies--bruising from vitamin K deficiency, bone pain from vitamin D deficiency, night blindness from vitamin A deficiency, and skin rashes, possibly from vitamin E or essential fatty acid deficiency. All these vitamin problems are related to the absence of bile to assist in the absorption of nutrients from the intestines.

Diagnosis

Blood tests strongly suggest the correct diagnosis, but a liver biopsy is needed for confirmation. It is also usually necessary to x ray the biliary system to look for other causes of obstruction.

Treatment

Of the many medicines tried to relieve the symptoms and slow the progress of this disease, only one has had consistently positive results. Ursodeoxycholic acid, a chemical that dissolves gall stones, provides substantial symptomatic relief. It is still unclear if it slows liver damage.

Primary biliary cirrhosis is a major reason for liver transplantation. Patients do so well that this is becoming the treatment of choice. As experience, technique, and immunosuppression progressively improve, patients with this disease will come to transplant surgery earlier and earlier in their disease course.

Prognosis

So far, this disease has not returned in a transplanted liver.

Key Terms

Biopsy

Surgical removal of tissue for examination.

Cirrhosis

Scarring, usually referring to the liver.

Immunosuppression

Techniques to prevent transplant graft rejection by the body's immune system.

Gale Encyclopedia of Medicine. Gale Research, 1999.