From the Guidelines
To rule out hepatitis as a cause of liver enzyme elevation, a standard liver aetiology screen or core panel should be ordered, including hepatitis B surface antigen, hepatitis C antibody, and other tests to identify the cause of damage and exclude additional pathologies, as recommended by the guidelines on the management of abnormal liver blood tests 1. When evaluating liver enzyme elevation, it is essential to consider the patient's clinical history, including age, ethnicity, symptoms, comorbidity, drug history, and travel history, to determine the likelihood of hepatitis as a cause.
- Key components of the core panel include:
- Hepatitis B surface antigen
- Hepatitis C antibody
- Autoantibodies (e.g., antinuclear antibody, smooth muscle antibody)
- Immunoglobulin levels
- Complete metabolic panel (ALT, AST, alkaline phosphatase, bilirubin, albumin)
- Complete blood count
- Prothrombin time/INR
- Additional testing may be necessary based on the patient's clinical presentation and the results of the initial core panel, such as hepatitis A antibody (IgM) and hepatitis E IgM in appropriate settings 1.
- Abdominal ultrasound should be performed to evaluate liver morphology and rule out biliary obstruction, and patients with evidence of hepatitis B or C, autoimmune hepatitis, or other specific liver diseases should be referred to a specialist clinic in accordance with locally agreed guidance 1.
- It is crucial to note that the country of origin (not ethnic group) was the strongest predictor of viral hepatitis, as found in the BALLETS study 1.
- A thorough medication review and alcohol use assessment are also essential in cases where drug-induced or alcoholic hepatitis is suspected.
- The choice of blood tests in the core panel is influenced by prevalence and the identification of treatable causes of liver disease, and the entire extended liver aetiology screen should only be undertaken in response to abnormal liver blood tests when the core panel does not reveal a clear cause 1.
From the Research
Specific Tests to Rule Out Hepatitis as a Cause of Liver Enzyme Elevation
To determine the cause of liver enzyme elevation, several tests can be ordered to rule out hepatitis. The following are some of the specific tests that can be used:
- Hepatitis panel: This includes tests for hepatitis A, B, and C, as well as other types of hepatitis 2, 3.
- Liver function tests: These tests measure the levels of certain enzymes and proteins in the blood that are produced by the liver, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) 2.
- Autoantibody tests: These tests detect the presence of autoantibodies, which are antibodies that attack the body's own tissues, such as antinuclear antibodies (ANA) and anti-smooth muscle antibodies (SMA) 4, 5, 6.
- Viral load tests: These tests measure the amount of viral genetic material in the blood, such as hepatitis C virus (HCV) RNA 2.
- Imaging tests: These tests use techniques such as ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI) to visualize the liver and detect any abnormalities 2.
Autoantibodies in Hepatitis
Autoantibodies are a key diagnostic tool in autoimmune hepatitis, and can also be detected in patients with chronic hepatitis B and C. The following are some of the autoantibodies that can be detected:
- Antinuclear antibodies (ANA): These antibodies are commonly detected in patients with autoimmune hepatitis, as well as in patients with chronic hepatitis B and C 4, 5, 6.
- Anti-smooth muscle antibodies (SMA): These antibodies are also commonly detected in patients with autoimmune hepatitis, as well as in patients with chronic hepatitis B and C 4, 5, 6.
- Anti-liver/kidney microsomal type 1 (anti-LKM1) antibodies: These antibodies are typically detected in patients with autoimmune hepatitis type 2 5, 6.
- Anti-soluble liver antigen (anti-SLA) antibodies: These antibodies are specific to autoimmune hepatitis and can be detected in patients with type 1 and type 2 autoimmune hepatitis 5, 6.