PSC is short for Primary Sclerosing Cholangitis, a chronic liver disease whereby the bile ducts, which are the passages that carry bile from the liver to the intestines, become narrowed from inflammation and fibrosis. Over time, the scar tissue builds up and can block parts of the bile ducts completely. The blockages can occur in any part of the biliary tree: inside the liver itself (intrahepatic) or outside the liver (extrahepatic).
The narrowed or blocked bile ducts interrupt the flow of bile out of the liver, causing a variety of symptoms; ultimately in some patients leading to biliary cirrhosis, portal hypertension, and liver failure. Common symptoms can include tiredness, generalised aching, pruritus (itching), pain in the upper right side of the abdomen, jaundice, chills and fevers. Many people with PSC are asymptomatic at the point of diagnosis, that is, don’t even show any outward symptoms to indicate they are living with a chronic illness. Not only that, but the progression of the disease is highly variable between patients: the speed of progression of PSC, severity and the number of symptoms cannot be predicted for the individual patient.
Who gets PSC?
PSC occurs in twice as many men as women. The age at which most patients present is between 25 and 40 years, though the condition may be diagnosed at any age and has recently become recognized as an important cause of chronic liver disease in children (Chapman, 2011).Chapman, 2011. Primary sclerosing cholangitis. Medicine,39(10): 588-591
What causes PSC?
The simple answer is that no one knows for sure. PSC is definitely not caused by drinking alcohol.
Current evidence suggests it is a combination of your genes, the immune system and some sort of trigger. People with a particular genetic make-up may be susceptible to particular toxic or infectious agents, which triggers their immune system to effectively ‘attack’ the bile ducts.
There is a close association with PSC and Inflammatory Bowel Disease (IBD), with around 70% of PSCers having IBD. It is possible that the toxins enter through the leaky gut, and gut lymphocytes (cells involved in the body’s immune response) attack both the gut and the bile ducts as well.
The British PSC Consortium is currently looking at possible genetic factors that might make people more susceptible to PSC. PSC Support is supporting this Genetic Study. All PSCers are encouraged to participate. The current emerging data suggest that PSCers have overactive immune systems that make them more likely to respond to trigger factors arising from the bowel by mounting a damaging attack on the bile ducts. This knowledge is allowing us to develop new approaches to therapy aimed at suppressing the overactive immune system and new treatments for PSC will be tested in clinical trials over the next few years.
Because of the differences in the clinical presentation of PSC in patients, it is possible that there are several different mechanisms at work, which can all lead to damage to the biliary tree. This possibility makes PSC difficult to study, and identifying any special populations of PSCers will aid research.
There is currently no known curative treatment, or treatment which is known to slow the progression of the disease, but we can manage some of our symptoms.