Hepatitis Testing

Hepatitis A

Hepatitis A testing is done to diagnose a liver infection due to the hepatitis A virus. The most commonly used test is the antibody test. There are different kinds of antibody tests that detect different classes of hepatitis A antibodies.

  • hepatitis testingHAV IgM antibody test: This kind of antibody test is done at the early stage of hepatitis A infection. It detects antibodies produced by a patient’s body once it has been exposed to the hepatitis A virus.
  • HAV IgG antibody test: The IgG antibody test is done at the later stage of a hepatitis infection since it detects for the IgG antibodies that remain in the body for years or for the entire lifetime of the patient. IgG antibodies’ main role is to protect the body from recurrent hepatitis infections. Thus, an IgG antibody test is best done to diagnose past hepatitis A infections. It may also be used to determine if a patient has been immune from the virus.
  • Total HAV antibody test: This antibody test can be used to detect both an early and later stage of a hepatitis A infection. Once a person has been injected with hepatitis A immunization, he or she can possibly have a positive result using this test although the person does not really have the hepatitis A infection.

Hepatitis B

Hepatitis B testing is used for various reasons. Some hepatitis B tests detect antibodies produced by the body while others detect antigens from the virus.

Usually, there are two types of test done for Hepatitis B. The first test detects the initial hepatitis infection. On the other hand, the second test’s purpose is to monitor the progress of the hepatitis B virus in the body and to detect chronic hepatitis B infection.

The following are the possible initial tests that can be done:

  • Hepatitis B surface antigen (HBsAG): HBsAG is used to identify proteins present in the surface of the hepatitis B virus. This test detects both acute and chronic hepatitis B infections and it is the most commonly used test since it can identify antigens even before there are noticeable symptoms.
  • Hepatitis B surface antibody (anti-HBs): This test detects antibodies produced by the body that fight the hepatitis B virus. Anti-HBs is primarily used to detect a previous hepatitis B infection. It can also be used to check if a person has been immune to the virus due to a vaccination, or a successful treatment.
  • Total anti-hepatitis B core (anti-HBc): The anti-HBc detects both the IgM and IgG antibodies produced by the body. The IgM antibodies are produced during the initial infection to HBV while IgG antibodies are produced in the later stage of the infection which will exist throughout the lifetime of the patient.

The following are follow-up tests that are mostly done to monitor a hepatitis B infection:

  • HBV IgM antibody test: This test is used to detect acute hepatitis B infections and only detects IgM antibodies.
  • Hepatitis B e-antigen: This test is mostly used to determine the ability of the hepatitis B virus to spread. It can also be used to know the effectiveness of a treatment. However, this test is not usually done in the Middle East and Asia since there are types of hepatitis B viruses that do not produce e-antigen.
  • Anti-hepatitis B e-antibody: This test is used to monitor acute infections in those patients who have been treated from acute hepatitis B infection.
  • Hepatitis B viral DNA: This test determines if HBV is reproducing in the body and is mostly used to monitor chronic HBV infections.
  • Hepatitis B virus resistance mutations: This test is mostly done to choose the right medications for patients especially those who have not been responding to their treatments.

Hepatitis C

Hepatitis C testing is done to diagnose if a person is positive for hepatitis C virus. The following tests are mostly done to detect and monitor hepatitis C infections:

  • HCV RNA test: This test is used to identify either a current and past hepatitis C infection.
  • HCV Viral load: This test is done by measuring the level of RNA particles in the blood. This is usually done before and after a treatment to determine the response of a patient to medications.
  • Viral genotyping: This is used to identify the genotype of the HCV. The most common of them, genotype 1, does not always respond to common treatments compared to genotypes 2 and 3. Thus, once a genotype 1 is detected, it usually takes a longer treatment. The test can also help in choosing the right medication for the patient.