Primary Sclerosing Cholangitis
Primary sclerosing cholangitis (PSC) is an uncommon, chronic and progressive disease that causes inflammation and scarring of the medium and large size bile ducts of the liver. As the scarring increases, the ducts become congested and blocked. The ducts are important because they carry bile out of the liver. Bile is a liquid that helps break down dietary fat. If the ducts are blocked, bile builds up in the liver, damaging liver cells. Blockage can also cause infection, with fever and right upper quadrant abdominal pain. Eventually, PSC can cause cirrhosis and liver failure. It may also cause bile duct cancer, or cholangiocarcinoma.
Causes
The cause of PSC is unknown, but it may be due to an immune system impairment or chronic infections. The disease usually begins between the ages of 30 and 60, but it can also arise during childhood. PSC is more common in men than woman, accounting for about 70%. In addition, about 90% will also have an inflammatory bowel disease, with the vast majority having ulcerative colitis.
Symptoms
Most patients with PSC are asymptomatic because the disease progresses slowly before symptoms develop. However, some can have a rapidly progressive course with early biliary duct obstruction. The main symptoms are fatigue, itching, or diarrhea. In more severe cases, it can present with infection-causing fevers, chills, abdominal pain, and jaundice (yellowing of the eyes and skin). PSC can also be associated with thinning of the bone, called osteoporosis.
Diagnosis
The first step is to check blood tests, as those with PSC often have abnormal liver tests with an elevated alkaline phosphatase (ALP), although a small subset may have normal ALP levels. Other liver tests called aspartate aminotransferase (AST) and alanine aminotransferase (ALT) may also be abnormal. Bilirubin levels are usually normal early in the disease but become abnormal as the degree of bile duct blockage increases.
PSC is diagnosed through cholangiography, which involves injecting dye into the bile ducts and taking an X-ray. Cholangiography can be performed as an endoscopic procedure (endoscopic retrograde cholangiopancreatography, ERCP), via radiology with a magnetic resonance imaging (MRI) scan specifically designed to look at the bile ducts (MRCP, magnetic resonance cholangiopancreatography), or via surgery.
Treatments
Treatment usually includes ursodeoxycholic acid; a medication used to make bile less toxic. Other medications to relieve itching, antibiotics to treat infections, and vitamin supplements, as people with PSC are often deficient in vitamins A, D, E, and K, may be necessary. In some cases, an ERCP is required to open major bile duct obstructions. No medication has been found to improve survival or the need for liver transplantation. Liver transplantation may be the only option if the liver fails.