Primary biliary cirrhosis
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Primary biliary cirrhosis is an autoimmune disease of the liver marked by the slow progressive destruction of the small bile ducts within the liver. When these ducts are damaged bile builds up in the liver (cholestasis) and over time damages the tissue. This can lead to scarring, fibrosis, cirrhosis. and ultimately liver failure. It is a rare disease, about 200 out of a million; 10 to 1 women to men, although different references vary widely on these numbers.
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Signs and symptoms
The following signs may be present in PBC:
- fatigue
- pruritus (itchy skin)
- jaundice (yellowing of the eyes and skin), due to increased bilirubin in the blood.
- xanthelasmas (focal collections of cholesterol in the skin, especially around the eyes)
- Complications of cirrhosis and portal hypertension:
- fluid retention in the abdomen (ascites)
- esophageal varices
- hepatic encephalopathy, up to coma, in extreme cases.
Diagnosis
To diagnose PBC, distinctions should be established from other conditions with similiar symptoms, such as autoimmune hepatitis or primary sclerosing cholangitis (PSC).
Diagnostic blood tests include:
- deranged liver function tests (high alkaline phosphatase, elevated AST, ALT)
- presence of certain antibodies: antimitochondrial antibody, antinuclear antibody
Abdominal ultrasound or a CT scan is usually performed to distinguish between the various possible causes. Ideally, everyone suspected of PBC should have a liver biopsy, and - if uncertainty remains - endoscopic retrograde cholangiopancreatography (ERCP, an endoscopic investigation of the bile duct).
Etiology
The cause of the disease is unknown at this time, but research indicates that there is an immunological basis for the disease, making it an autoimmune disorder. Most of the patients (<90%) seem to have auto-mitochondrial antibodies (AMAs) against pyruvate dehydrogenase complex (PDC-E2), an enzyme that is found in the mitochondria.
Therapy
There is no known cure, but medication may slow the progression so that a normal lifespan and quality of life may be attainable. Ursodeoxycholic acid (Ursodiol) is one, which helps reduce the cholestasis. To relieve itching caused by bile acids in circulation, which would normally be removed by the liver, cholestyramine (a bile acid sequestrant) may be prescribed to absorb bile acids in the gut and be eliminated, rather than enter the blood stream. As in all liver diseases, alcoholic beverages are contraindicated. In advanced cases, a liver transplant, if successful, is said to have excellent prognosis.
References
Medical
- Template:OMIM
- M. Eric Gershwin, John M. Vierling, Michael P. Manns, eds. Liver Immunology. Philadelphia, Pa.: Hanley and Belfus, 2003. ISBN 1560534990. (State of the art; technical.)
General
- Sanjiv Chopra. The Liver Book: A Comprehensive Guide to Diagnosis, Treatment, and Recovery, Atria, 2002, ISBN 0743405854
- Melissa Palmer. Dr. Melissa Palmer's Guide to Hepatitis and Liver Disease: What You Need to Know, Avery Publishing Group; Revised edition May 24, 2004, ISBN 1583331883. her webpage (http://www.liverdisease.com).
- Howard J. Worman. The Liver Disorders Sourcebook, McGraw-Hill, 1999, ISBN 0737300906.
External links
- PBCers.org (http://pbcers.org) - patients' organisation
- A summary of relevant research (http://pbcers.org/research.htm) (2004)
- Current PBC clinical trials (http://pbcers.org/currentresearch.htm)
- June 2005 National (USA) PBC conference (http://pbcers.org/2005MC.htm)
- Dr. Gershwin's research lab at UC Davis (http://internalmedicine.ucdmc.ucdavis.edu/who/rheumatology/PBC_Lab/) Many research papers online.
- PBC Foundation UK (http://www.pbcfoundation.org.uk/)
- Howard J. Worman's Columbia University web site, with a clear overview of PBC (http://cpmcnet.columbia.edu/dept/gi/PBC.html)