Hepatitis B

Diagnosis and monitoring

Blood tests

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.

Glossary

alpha-fetoprotein (AFP)

A protein found in the blood, used to detect early signs of liver cancer.

biopsy

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 inflammation.

cirrhosis

Scarring of the liver – the structure of the liver is altered. See also ‘fibrosis’, which is moderate scarring. See also ‘compensated cirrhosis’ and ‘decompensated cirrhosis’.

DNA

Deoxyribonucleic acid, 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.

fibrosis

Scarring of the liver – the development of hard, fibrous tissue. See also ‘cirrhosis’, which is more severe scarring.

histology

Examining a sample of cells under a microscope to determine if they are normal or if there is evidence of infections or tumours.

invasive

In medical terms, going inside the body.

Important tests for hepatitis B

Antigens (Ag) are substances which the body identifies as foreign (e.g. virus components) and which lead to the production of antibodies (Ab).

HBs antigen

Virus component in the virus envelope; a sign of acute or chronic hepatitis B.

HBe antigen

Virus component detected in the blood. Indirect evidence of virus multiplication (replication).

HBc antigen

An element of the virus capsule. May be detected in the liver but not in the blood.

Antibodies (anti-HBs, anti-HBe, anti-HBc)

Produced by the body’s immune system to remove the virus from the body.

HBV DNA

Genetic material from the hepatitis B virus (deoxyribonucleic acid).

Transaminases

Liver enzymes (ALT, AST) indicating increased inflammatory activity in the liver.

Histology

Microscopic examination of tissue (e.g. from the liver).

Liver biopsy (liver tissue sampling)

In order to estimate the extent of connective tissue infiltration and inflammatory activity in the liver for example, as a basis for deciding on treatment liver biopsy is recommended. Biopsy of the liver involves the removal of a small piece of tissue (under local anaesthesia) for histological examination under a microscope. Another liver biopsy after completion of treatment may be indicated in order to assess the response to treatment. Non-invasive procedures (laboratory markers, elastography) are fairly reliable predictors of cirrhosis even in the absence of liver biopsy.

This information is adapted from Hepatitis B: Risks, prevention and treatment by Prof. Stefan Zeuzem, published by the European Liver Patients Association, 2007.