March 11, 2011
Dear Mayo Clinic:
My son is 30 years old and was just diagnosed with PSC. Can you tell us more about it? How is it treated?
Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the bile ducts that may lead to severe liver damage and liver failure. Although PSC gets worse over time in most cases, the time it takes for the disease to progress can vary significantly. Currently, no effective medical therapy is available for PSC. Eventually most people with end-stage liver disease due to PSC are considered for a liver transplant.
"Cholangitis" refers to inflammation of the bile ducts. "Sclerosing" describes the hardening and scarring of the bile ducts that result from chronic inflammation. Bile ducts are the structures through which bile flows from the liver to the intestines. Bile helps the body absorb nutrients and other elements from food and also helps maintain the nutritional balance within the body.
The structure of the bile ducts resembles a tree. A single bile duct outside the liver connects to the small intestine. That duct branches into two main ducts (left and right hepatic ducts). From those two ducts a series of branches form. Those branches become smaller and smaller as they go farther into the liver. PSC can affect small, medium or large bile ducts.
What causes PSC is unclear. Researchers believe a combination of genetic predisposition and immune system factors could be involved. The immune system reaction associated with PSC may be triggered by exposure to toxins in a person's environment or, possibly, by an infection in people who are genetically predisposed to the disease. People who have inflammatory bowel disease are susceptible to developing PSC, although it's not clear how the two disorders are linked.
In the past, when doctors were less familiar with PSC, people with this disease often weren't diagnosed until the condition was in its advanced stages. Signs and symptoms of advanced PSC include yellowing of the eyes or skin (jaundice), itching, abdominal pain, leg swelling and infection. Today, PSC is often caught much sooner, before these symptoms appear, based on results from routine blood tests that may suggest liver problems. A special imaging exam of the bile ducts, called cholangiography, is typically used to definitively diagnose PSC. A liver biopsy may be performed to determine how much scar tissue has developed in the liver from PSC.
No medical treatment exists at this time that can effectively slow the progression of PSC. Instead, treatment is focused on decreasing PSC symptoms using a combination of medical therapies and procedures. Itching, for example, can be treated with a variety of medications, such as oral powders that bind to bile in the intestines. Balloon dilation and stent placement using specialized endoscopic procedures may be used to open blockages in the larger bile ducts.
Lifestyle changes can help manage PSC, too. For example, quitting smoking, avoiding alcohol, eating a healthy diet with lots of fruits, vegetables and whole grains, maintaining a healthy weight, and getting vaccinated against hepatitis A and B may help preserve liver function.
Ultimately, though, no medication is available that directly halts or reverses the liver injury caused by PSC. Eventually, people with end-stage liver disease from PSC often benefit from a liver transplant. In the past, when people were more often diagnosed with advanced PSC, the average time to a liver transplant was usually 10 to 12 years. Because many people are being diagnosed earlier, the average time to transplant is now longer and may be around 15 to 20 years. But that can vary significantly. Some people with PSC rapidly progress and need a transplant much sooner. Others may carry the disease for decades without showing any significant progression.
ā Jayant Talwalkar, M.D, M.P.H., Gastroenterology, Mayo Clinic, Rochester, Minn.