When you get tested for hepatitis C you will have a blood test first. The blood is screened for antibodies to the hepatitis C virus.
Antibodies are proteins of the immune system. Your body makes them as part of its defence against infection by helping to destroy ‘foreign’ molecules, such as those of the hepatitis C virus. Antibodies that are specific to the hepatitis C virus are only made when the hepatitis C virus is present. So if they are found in your blood, it means you have been in contact with the hepatitis C virus at some point. However, the presence of antibodies doesn’t necessarily mean that you still have the virus in your blood.
The extra definitive test actually measures the quantity of the genetic material, RNA of the hepatitis C virus, usually by a technique called polymerase chain reaction (PCR) or it variants: hence the test is generally called the PCR test.
People for whom hepatitis C testing is recommended* include:
*From the practice guidelines of the American Association for the Study of Liver Diseases (AASLD)
As well as confirming the presence of antibodies and RNA, the doctor may also request that your blood may be tested for transaminases. Transaminases (ALT, AST) are enzymes that are released from the liver cells when the liver is inflamed. When the levels of the transaminases are high it suggests that there is inflammation of the liver. However, the increase in the level of transaminases does not correlate directly with the amount of liver damage.