What is primary sclerosing cholangitis (PSC)?Primary sclerosing cholangitis (PSC) is an inflammatory disease of the bile duct, which leads to cholestasis (blockage of bile transport to the gut). Bile is necessary for the absorption of dietary fat. Blockage of the bile duct leads to accumulation,
damages the liver (leading to jaundice) and eventually causes liver failure. PSC is considered an autoimmune disease. In primary sclerosing cholangitis (PSC), the bile ducts inside and outside the liver become inflamed and scarred. As the scarring increases, the ducts become blocked. The ducts are important because they carry bile out of the liver. Bile is a liquid that helps break down fat in food. If the ducts are blocked, bile builds up in the liver and damages liver cells. Eventually, PSC can cause liver failure.
The term cholangitis means inflammation of the bile ducts. The term applies to inflammation of any portion of the bile ducts, which carry bile from the liver to the gallbladder and intestine. The inflammation is produced by bacterial infection or sometimes other causes. Bile, which is needed for digestion, is produced in the liver and then enters the common bile duct (CBD) through the hepatic ducts. Bile enters the gallbladder between meals, when the muscle or sphincter that controls flow of bile between the CBD and intestine is closed. During this period, bile accumulates in the CBD; the pressure in the CBD rises, as would a pipe closed off at one end. The increase in pressure eventually causes the bile to flow into the gallbladder. During meals, the gallbladder contracts and the sphincter between the gallbladder and intestine relaxes, permitting bile to flow into the intestine and take part in digestion.