FAQs - Distinguishing Between PSC and PBC
What is PSC?
Primary sclerosing cholangitis (PSC) is part of the family of liver diseases that affect the bile ducts – tubes that deliver bile from the liver to the small intestine. PSC causes inflammation in medium and large sized bile ducts (cholangitis) inside and outside of the liver, which results in hardening (sclerosis) and narrowing of the ducts. As a result, bile cannot be released properly and it builds up in the liver where prolonged exposure results in liver damage.
PSC affects more men (70%) than women (30%), and most patients also have inflammatory bowel disease. PSC is usually diagnosed using blood tests and imaging or a liver biopsy. While PSC is the least common of the family of autoimmune liver diseases, it is the leading indication for liver transplantation.
What is PBC?
Primary biliary cholangitis (PBC), formerly known as primary biliary cirrhosis, is a chronic liver disease resulting from progressive destruction of the small bile ducts within the liver. PBC affects mostly women (90%), does not classically overlap with inflammatory bowel disease and is usually diagnosed through a blood test. Medical treatments for PBC have proven more effective than for PSC, and most patients with PBC will be managed with Ursodeoxycholic acid (UDCA) or Obeticholic acid, hopefully avoiding transplantation in the majority.
Why the name change?
The international PBC community, in a patient led initiative, opted to change the disease’s name from primary biliary cirrhosis to primary biliary cholangitis for several reasons. One was to avoid the stigma of the term “cirrhosis.” PBC patients hope that changing the name will help prevent an ongoing misconception by some that their disease is caused by alcohol consumption. In addition, with effective medical treatments that include Ursodeoxycholic acid and Obeticholic acid, a majority of patients with PBC may never develop true cirrhosis.
PSC Partners Seeking a Cure and PSC Support respect the effort made by patients with PBC to change their disease name, and are keen to use the opportunity afforded to ensure that education about these rare liver diseases is improved for all, within which includes ensuring no confusion to patients and non-expert clinicians, from using very similar terms, for what are two very different diseases.
What problems might be caused by confusion between the two diseases?
The concerns about confusion and incorrect diagnoses stem from the fact that the new name makes PSC and PBC sound like the same disease to non-experts. However, the two diseases are not the same, despite sharing certain similar characteristics and symptoms. It is important to know the difference between the two diseases, because PSC and PBC carry different clinical needs, including diagnosis, treatment, and surveillance.
One significant difference between the two diseases is that PSC is considered a premalignant disease, which presents an increased risk of colon and bile duct cancers. Accordingly, patients with PSC need to be closely monitored for cancer. PBC does not increase one’s risk for these cancers.
An incorrect diagnosis of PBC when a patient has PSC could result in a lack of regular cancer screening, which could have disastrous results for patients with PSC. Further, patients with PBC might be mistaken for being at risk of infective cholangitis, a condition frequently of clinical concern for those with PSC.
In addition, unlike most patients with PSC, a large number of patients with PBC respond to treatment using Ursodeoxycholic acid and/or Obeticholic acid. An incorrect diagnosis of PSC when a patient has PBC could result in a patient not being offered a treatment that could slow down their disease progression.