From the Guidelines
Liver function can be evaluated through a combination of blood tests, imaging tests, and liver biopsy, with the most recent and highest quality study suggesting the use of blood-based biomarkers for staging liver fibrosis in chronic liver disease 1. To evaluate liver function, several tests can be performed, including:
- Blood tests: liver function tests (LFTs) that measure enzymes like ALT, AST, ALP, and GGT, as well as bilirubin levels, which help detect inflammation, damage, or impaired function 1
- Imaging tests: ultrasound, CT scans, MRI, and fibroscan can visualize the liver structure and detect abnormalities like fatty liver, cirrhosis, or tumors 1
- Liver biopsy: a small tissue sample is removed and examined under a microscope, which is particularly useful for diagnosing conditions like hepatitis, cirrhosis, or cancer 1
- Non-invasive tests: FibroSure or FibroTest use blood markers to estimate liver fibrosis, and specialized tests may be ordered to diagnose specific liver conditions, such as hepatitis viral tests, autoimmune markers, iron studies for hemochromatosis, or copper studies for Wilson's disease 1 The severity of abnormal aminotransferase can be classified as mild, moderate, or severe, and the choice of test depends on the clinical presentation, risk factors, and abnormal findings on routine examinations 1. In patients at risk for chronic liver disease, checking for liver risk factors, testing AST, ALT, GGT, ALP, and platelet count, and calculating FIB-4 can help identify significant fibrosis 1. The use of blood-based biomarkers for staging liver fibrosis in chronic liver disease has been shown to be accurate and reliable, making it a valuable tool in the diagnosis and management of liver disease 1.
From the Research
Diagnostic Tests for Liver Function
The following diagnostic tests can be performed to evaluate liver function:
- Serum alanine aminotransferase (ALT) 2
- Aspartate aminotransferase (AST) 2
- Alkaline phosphatase 2
- Bilirubin 2
Interpretation of Test Results
The results of these tests can indicate:
- Hepatocellular injury: disproportionate elevation of AST and ALT levels compared with alkaline phosphatase levels 2
- Cholestatic injury: disproportionate elevation of alkaline phosphatase level as compared with AST and ALT levels 2
Further Evaluation
Further evaluation may include:
- Testing for viral hepatitis A, B, and C 2
- Assessment for nonalcoholic fatty liver disease and alcoholic liver disease 2
- Screening for hereditary hemochromatosis, autoimmune hepatitis, Wilson's disease, and alpha-1 antitrypsin deficiency 2
- Testing for primary biliary cholangitis and primary sclerosing cholangitis 2
Additional Tests
Additional tests that may be considered include: