Hepatitis B is diagnosed by testing for various antigens
and antibodies (see table below). The main markers are anti-HBc antibody and
HBs antigen. If an HBs-Ag test is positive, further tests should be done to
establish the hepatitis activity. These tests are HBe-Ag and anti-HBe assays
and direct measurement of the amount of virus DNA in the blood (viral load).
Liver function tests (ALT, AST) are of limited value
in indicating the inflammatory activity associated with hepatitis. The disease
activity and connective tissue reaction in the liver can be evaluated reliably
only by investigating a sample of liver tissue. Non-invasive procedures such as
elastography give an indirect indication of the degree of fibrosis.
Since people with chronic hepatitis B are at
greater risk of developing liver cancer, alpha-fetoprotein (AFP), a tumour
marker for liver cancer, should be monitored and ultrasound scans of the liver
should be done at half-yearly intervals.
- alpha-fetoprotein (AFP)
A protein found in the blood, used to detect early signs of liver cancer.
A small sample of
tissue removed from the body and examined for signs of disease. A liver biopsy
is the most reliable way of assessing the extent of liver scarring and
Scarring of the liver – the structure of the liver is altered. See also
‘fibrosis’, which is moderate scarring. See also ‘compensated cirrhosis’ and
the material in the nucleus of a cell where genetic information is stored. In
hepatitis B, DNA (viral load) testing is used to help predict treatment outcome
and to monitor response to treatment.
Scarring of the liver
– the development of hard, fibrous tissue. See also ‘cirrhosis’, which is more
a sample of cells under a microscope to determine if they are normal or if
there is evidence of infections or tumours.
medical terms, going inside the body.