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.
What does the liver do?
The liver is in the upper right part of the abdomen. It has many functions which include:
- Storing glycogen (fuel for the body), which is made from sugars. When required, glycogen is broken down into glucose which is released into the bloodstream.
- Helping to process fats and proteins from digested food.
- Making proteins that are essential for blood to clot (clotting factors).
- Processing many medicines which you may take.
- Helping to remove or process alcohol, poisons and toxins from the body.
- Making bile, which passes from the liver to the gut down the bile duct. Bile breaks down the fats in food so that they can be absorbed from the bowel.
What are the symptoms of PSC?
Many people with PSC do not get symptoms, especially in the early stages of the disease. When symptoms do occur the most common are fatigue, pruritus, or itching of the skin, and jaundice, a yellowing of the skin and eyes.
These symptoms may come and go, but they may worsen over time. As the disease continues, the bile ducts may become infected, which can lead to episodes of fever, chills and abdominal pain.
What causes PSC?
The cause of this disease is not known. About 70 percent of patients are men. It may be related to bacterial or viral infections, as well as problems in the immune system.
Genetic factors may also play a role. PSC is considered an uncommon disease, but recent studies suggest that it may be more common than previously thought.
How is PSC diagnosed?
Because many PSC patients have no symptoms, the disease is often discovered through abnormal results on routine liver blood tests. Formal diagnosis is usually made by cholangiography, an X-ray test involving injection of dye into the bile ducts, or by a MRI.
What are the symptoms of primary sclerosing cholangitis?
In many cases the symptoms develop gradually over weeks or months. At the beginning of the disease, many people have no symptoms at all.
The most common early symptoms include feeling more tired than usual, feeling generally unwell, itchy skin, weight loss and having some discomfort in the right upper tummy (abdomen).
Jaundice can develop when the condition worsens. Jaundice is when you ‘go yellow’. You tend to notice it first when the whites of the eyes become yellow. This is due to a build-up of the chemical bilirubin, which is made in the liver and, in some liver conditions, spills into the blood.
What are the complications of primary sclerosing cholangitis?
Various complications can occur in some people with PSC. These include:
- Deficiencies of some vitamins, usually vitamins A, D, E and K. These are the vitamins which are fat-soluble (rather than the other vitamins which are water-soluble). This means they dissolve in fat. Bile helps the fat to be broken down and these vitamins to be absorbed.
- Infection of the blocked bile ducts. This is called infective cholangitis. This may cause chills, fever and upper tummy (abdominal) tenderness.
- Cirrhosis (where normal liver tissue is replaced by scar tissue (fibrosis).
- Liver failure.
- Bile duct cancer. This eventually affects around 1 in 10 people who have PSC.
How is PSC treated?
There is no cure or specific treatment for PSC. The itching associated with the disease can be relieved with medication, and antibiotics are used to treat bile duct infections when they occur.
Most people with PSC must take vitamin supplements. In some cases, bile duct surgery or endoscopy may be useful to temporarily improve bile flow.