From the Guidelines
Laboratory tests for primary biliary cirrhosis (PBC) should include antimitochondrial antibodies (AMA), liver function tests, complete blood count, prothrombin time, albumin levels, and imaging studies such as ultrasound or magnetic resonance cholangiopancreatography (MRCP). The most recent and highest quality study, 1, recommends the use of non-invasive tests, such as the ELF score and liver stiffness measurement (LSM) by transient elastography (TE), to evaluate liver disease severity and prognosis in patients with PBC. Key laboratory tests for PBC include:
- Antimitochondrial antibodies (AMA), which are positive in about 95% of patients
- Liver function tests showing a cholestatic pattern with elevated alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT)
- Complete blood count, prothrombin time, and albumin levels to assess disease severity
- Immunoglobulin levels, particularly IgM, which are often elevated
- Other autoantibodies like anti-nuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA) may be present Imaging studies, such as ultrasound or MRCP, should be performed to exclude other causes of biliary obstruction. Liver biopsy can confirm the diagnosis, stage the disease, and rule out overlap syndromes, but is not always necessary for diagnosis when AMA is positive with consistent clinical features. Regular monitoring of these parameters is essential for disease management, with frequency depending on disease severity. These tests help diagnose PBC and distinguish it from other liver diseases with similar presentations, as noted in 2, 3, 4, 5, 6, and 7.
From the Research
Labs for Primary Biliary Cirrhosis
- The diagnosis of primary biliary cirrhosis (PBC) is based on the presence of at least 2 of 3 key criteria, including a persistently elevated serum alkaline phosphatase, the presence of serum anti-mitochondrial antibodies (AMAs), and liver histology consistent with PBC 8.
- Anti-nuclear antibodies specific to PBC are useful in cases in which AMAs are not detected and may indicate a more aggressive course 8.
- Laboratory results for PBC patients may include elevated serum alkaline phosphatase, elevated serum alanine aminotransferase, and elevated serum immunoglobulin G 9, 10.
- The presence of AMAs is a sensitive and specific marker for PBC, and is present in 95% of patients with PBC 11.
- AMA negative patients may have a significantly worse prognosis compared to AMA positive patients, with a reduced survival free of liver-related complications including transplantation and death 11.
Key Laboratory Tests
- Serum alkaline phosphatase
- Anti-mitochondrial antibodies (AMAs)
- Anti-nuclear antibodies
- Serum alanine aminotransferase
- Serum immunoglobulin G
- Liver histology
Diagnosis and Prognosis
- The diagnosis of PBC is based on a combination of laboratory tests and liver histology 8, 9, 12.
- The prognosis for PBC patients is generally good, with ursodeoxycholic acid (UDCA) therapy delaying or preventing disease progression in most cases 8, 9, 12.
- However, a subgroup of patients does not adequately respond to UDCA and may require new therapies 8.
- AMA negative patients may have a worse prognosis compared to AMA positive patients, with a reduced survival free of liver-related complications including transplantation and death 11.