Learn The BasicsPrimary biliary cholangitis (PBC) is a rare disease, and in some cases, patients may not present with any symptoms at all. It is usually diagnosed during a routine blood test. When symptoms are present, they may include bone or joint aches, fatigue, itchy skin, pain and discomfort, dry mouth and dizziness.
If the blood test results indicate the presence of PBC, a medical history and a physical exam, including imaging tests such as an ultrasound and a liver biopsy may be conducted to assess the bile ducts and the liver.
Medical history and physical exam
Risk factors associated with PBC include genetic predisposition and exposure to certain chemicals and certain infections. So, while determining your medical history, the doctor may ask whether anybody else in the family has been diagnosed with PBC or any other autoimmune diseases and whether you are smoking or have been exposed to toxic chemicals.
A physical examination may include the doctor checking for jaundice or yellowing in the skin and the whites of the eyes due to bilirubin. The doctor may also check for any liver or spleen enlargement and tenderness or pain around the site of the liver on the right-hand side of the body, though these symptoms usually do not occur until the later stages of the disease.
Blood tests
The blood tests that can help diagnose PBC include anti-mitochondrial antibody (AMA) tests and liver enzyme tests such as alkaline phosphatase and cholesterol tests.
Almost all patients with PBC (95%) have AMA in their blood, so this is a strong indicator of PBC.
Alkaline phosphatase is not specific to PBC and is usually elevated in all diseases where bile ducts are damaged, including illnesses such as infection, biliary stones and cancer. PBC can also cause levels of cholesterol to be higher than normal in the blood.
Other liver enzymes that may be monitored include alanine transaminase (ALT) and aspartate transaminase (AST). Antinuclear antibodies are present in around 30% of patients with PBC, and a doctor may also check for these.
Bilirubin in the blood is usually not elevated in PBC until later stages of the disease and is not used as a diagnostic tool in PBC.
Imaging tests
An ultrasound scan can help rule out other possible causes of bile duct damage, such as biliary stones, tumors or bile duct stricture, or abnormal narrowing that could occur from birth or as a result of inadequate surgery.
In some cases, a magnetic resonance imaging (MRI) scan may also be performed to help rule out other conditions affecting the bile ducts or liver.
Liver biopsy
If all other tests are inconclusive, a liver biopsy may be performed. It involves taking a small sample from the liver using a long needle. This is an invasive procedure that requires local anesthetic and a skilled clinician.
The sample can then be observed under a microscope to rule out any other diseases, confirm the presence of PBC and assess the activity level and stage of the disease.
Reviewed by Harshi Dhingra, M.D., on December 17, 2023.
