Test results

The most reliable way to know if someone has ever been infected with the hepatitis C virus is to get their blood tested for antibodies against the virus. The body takes an average of 7-8 weeks to produce these antibodies, but it could be longer; therefore, if the possible time of infection was recent and the antibody test is negative, the test should be repeated in 6 months.

If the antibody test is positive, it means that the individual has been exposed to the hepatitis C virus and another test is necessary to see if the virus is still present (because 10-30% of people clear it spontaneously). The doctor may also suggest other tests to find out how much the liver has been damaged. 

A polymerase chain reaction (PCR) test is used to see whether there is any virus present. This test uses molecular techniques to increase the amount of genetic material (RNA) from the hepatitis C virus present in a blood sample. If the PCR test is positive, then the individual is infected with the hepatitis C virus. The PCR test can also be used to identify the genotype of the virus (there are six different genotypes of the hepatitis C virus) and how much virus is present (viral load). In some cases, where a person is known to have reduced antibody production (for example if infected with HIV), it is necessary to test for hepatitis C using the PCR method directly. 

Transaminase tests measure the levels of certain liver enzymes in the blood and indicate liver inflammation, especially in the case of the most commonly tested enzyme, alanine aminotransferase (ALT). The results of these tests will vary over time and, therefore, they may be repeated on different occasions.

A liver biopsy may also be performed as this is a more accurate way to assess how damaged somebody’s liver is. It may not always be necessary to perform a biopsy, but the doctor’s decision will depend on many factors, including virus genotype. Liver biopsies are carried out under local anaesthetic and generally don’t require an overnight stay in the hospital. A small piece of the liver is removed using a needle and sent to be examined under a microscope. The results are graded depending on how much inflammation and scarring there is. Biopsies are also useful to monitor the extent of liver damage over time and may be conducted every 3 to 5 years in some circumstances. There are other non-invasive tests being increasingly used that can predict the extent of liver damage, such as fibrosis markers or transient elastography. 

The results of these tests will help your doctor to assess your level of liver disease and make recommendations for your future management.