Learn The BasicsPrimary biliary cholangitis (PBC) is a chronic and progressive autoimmune disease in which the body’s immune system mistakenly attacks the bile ducts in the liver. This leads to bile buildup in the liver, causing damage and scarring. As the disease progresses, the scarring can get worse, resulting in cirrhosis, which means the liver is no longer functional.
History of PBC
The earliest description of PBC dates back to 1761 when the Italian anatomist and pathologist Giovanni Battista Morgagni described an obstructed liver as “hard, green and scirrhous”.
However, the first clinical case was described in 1851 by Addison and Gull, who reported a case in which a woman presented with xanthelasma (a type of cholesterol deposit in the skin), brown skin and hepatosplenomegaly (swelling of the liver and the spleen).
In 1950, Ahrens and colleagues first introduced the name primary biliary cirrhosis, which was later changed to PBC in 2015, because cirrhosis occurs only in advanced stages and thus does not go well with early disease stages. Also, the old name wrongly suggested that the disease was associated with stigma related to excessive alcohol consumption.
How common is PBC?
The incidence (or the probability of occurrence) and prevalence (or commonality) of PBC vary greatly according to region, ethnicity and age.
However, the disease is usually more common among women than men and among Caucasians compared to other ethnic groups.
The incidence and prevalence of the disease also change with age, usually peaking between ages 60 to 79. It is very rarely seen in persons younger than age 25 and is typically diagnosed in women, ages 40 to 60.
The pooled global incidence of PBC is estimated to be 1.76 per 100,000 people, and the pooled global prevalence is estimated to be 14.6 per 100,000 people.
Causes and risk factors
The exact cause of PBC is not known, but it is thought that genetic and environmental risk factors such as infections, cigarette smoke and other toxic chemicals may increase the risk of developing the disease.
The risk of developing PBC is also higher among women, people ages 30 to 60 and those with a relative who has been diagnosed with the disease.
Stages and prognosis
PBC starts with an autoimmune attack leading to inflammation in the bile ducts of the liver. This inflammation can damage the bile ducts and lead to cholestasis, or a decrease in bile flow, resulting in the build-up of bile acids. Ongoing cholestasis can cause liver fibrosis, and in later stages, cirrhosis and liver failure.
The course of the disease varies greatly from one patient to the other, but generally, half of the patients without symptoms, which may include bone or joint ache, fatigue, pruritus or itchy skin and dizziness, usually develop liver disease in the next 15 years. The slower the disease progresses, the longer the survival.
The levels of bilirubin can help predict prognosis, with patients with bilirubin levels constantly above two mg/dL in their blood having a mean survival time of four years and those with levels constantly above 10 mg/dL having a mean survival time of 1.4 years.
Patients with PBC who have developed cirrhosis are good candidates for a liver transplant.
Reviewed by Harshi Dhingra, M.D., on December 14, 2023.
