Primary sclerosing cholangitis (PSC) is a chronic, or long-term, disease that slowly damages the bile ducts. Bile is a digestive liquid that is made in the liver. It travels through the bile ducts to the gallbladder and the small intestine, where it helps digest fats and fatty vitamins.
In patients with PSC, the bile ducts become blocked due to inflammation and scarring or fibrosis. This causes bile to accumulate in the liver, where it gradually damages liver cells and causes cirrhosis, or fibrosis of the liver. As cirrhosis progresses and the amount of scar tissue in the liver increases, the liver slowly loses its ability to function. The scar tissue may block drainage of the bile ducts leading to infection of the bile.
PSC advances very slowly. Many patients may have the disease for years before symptoms develop. Symptoms may remain at a stable level, they may come and go, or they may progress gradually. Liver failure may occur 10-15 years after diagnosis, but this may take even longer for some PSC patients. Many people with PSC will ultimately need a liver transplant, typically about 10 years after being diagnosed with the disease. PSC may also lead to bile duct cancer. Endoscopy and MRI tests may be done to monitor the disease.