The liver produces bile, a cholesterol-rich fluid that aids in the intestinal digestion of fats. A network of ducts--the biliary system--collects and transports bile from the liver to the gallbladder and on to the small intestine. Chronic obstruction of the biliary system causes a backup of bile in the liver, leading to damage and tissue scarring. Extensive bile-induced scarring that distorts the structure and function of the liver is called biliary cirrhosis. Several diseases and conditions can cause biliary cirrhosis.
Small Bile Duct Destruction
An errant attack on the small liver bile ducts by the immune system causes primary biliary cirrhosis. People with primary biliary cirrhosis produce antimitochondrial antibodies, which trigger the destructive immune system attack on the bile ducts. The 2009 primary biliary cirrhosis practice guidelines issued by the American Association for the Study of Liver Diseases reports that 90 to 95 percent of people with primary biliary cirrhosis have antimitochondrial antibodies.
Primary biliary cirrhosis is a chronic, progressive condition. As of 2009, ursodeoxycholic acid remains the only medication approved by the U.S. Food and Drug Administration for the treatment of primary biliary cirrhosis. Ursodeoxycholic acid may slow the progression of primary biliary cirrhosis, according to the American Association for the Study of Liver Diseases. The drug does not relieve disease symptoms such as chronic itching and fatigue.
Medium and Large Bile Duct Inflammation
Chronic inflammation of the medium and large bile ducts characterizes the disease, primary sclerosing cholangitis (PSC). Inflammation-induced scarring leads to narrowing of the medium and large bile ducts, which impedes bile outflow from the liver. The resulting backup of bile leads to liver scarring, which may progress to cirrhosis and liver failure.
Whereas primary biliary cirrhosis affects more women than men, the opposite is true with primary sclerosing cholangitis. In an online article posted by the American College of Gastroenterology, Drs. Marvin Lopez and Young-Mee Lee report that approximately 70 percent of patients with primary sclerosing cholangitis are male. Notably, most patients with primary sclerosing cholangitis also have inflammatory bowel disease. Approximately 87 percent of patients have ulcerative colitis and 13 percent have Crohn's disease, report Lopez and Lee.
Bile Duct Absence or Loss
Biliary atresia is a condition affecting newborn babies wherein the absence or loss of bile ducts causes a buildup of bile in the liver. Failure to form a normal biliary system during development in the womb causes some cases of biliary atresia. In other cases, the bile ducts are destroyed shortly after birth. As with other causes of biliary cirrhosis, the backup of bile in the liver leads to progressive liver scarring, cirrhosis and possible liver failure.
Liver damage associated with biliary atresia often progresses rapidly and may lead to liver failure within the first two years of life, reports the National Institute of Diabetes and Digestive and Kidney Diseases. Approximately 85 percent of children with biliary atresia require a liver transplant before age 20, reports Cincinnati Children's Hospital Medical Center.
References
- "Hepatology"; Primary Biliary Cirrhosis; Keith D. Lindor, M.D., et al.; July 2009
- The American College of Gastroenterology: Primary Sclerosing Cholangitis and Primary Biliary Cirrhosis
- National Institute of Diabetes and Digestive and Kidney Diseases: Biliary Atresia
- Cincinnati Children's Hospital Medical Center: Biliary Atresia
- National Institute of Diabetes and Digestive and Kidney Diseases: Primary Biliary Cirrhosis
