investigations
Last reviewed 08/2021
- liver function tests:
- serum alkaline phosphatase is markedly raised in more than 95% of cases, and usually from an early stage
- typically the serum ALP will be raised up to three or four times normal (1)
- mild elevation of aminotransferases alanine aminotransferase [ALT] or aspartate aminotransferase [AST] - raised later rather than early
- increased levels of immunoglobulins – mainly IgM
- late features
- serum bilirubin is raised in most cases
- alterations in prothrombin and serum albumin
- immunology:
- anti-mitochondrial antibodies (specifically to the M2 antigen) occur in 95% of cases - these may rarely be seen in a small proportion of patients with chronic active hepatitis or cryptogenic cirrhosis
- smooth muscle antibodies in 50%
- antinuclear factor in 20%
- IgM is raised in more than 80% of cases
- negative ANCA
- increased cholesterol levels
- liver biopsy
- confirms the diagnosis but not mandatory to make the diagnosis
- useful for assessment of the activity and staging of the disease
- stainable levels of copper may approach that seen in Wilson's disease as a result of the cholestasis.
- imaging
- MRI or endoscopic retrograde cholangiography – to exclude primary sclerosing cholangitis or other disorders that might lead to chronic cholestasis
- transient elastography - to evaluate the degree of liver fibrosis,
- thyroid function tests often reveal a lowered T4.
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