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What does the surface antigen marker in hepatitis B indicate?

Dr Shirish Kumar
Haematologist,
WHO,
Geneva

Q: I am suffering from hepatitis B (surface antigen). First it was 11.4 ratio in titre test (Elisa method by Thyrocare) and now it is 4.0 ratio. I am taking herbal medicines for this. What should be my next step?

A:There are many markers of hepatitis B virus (HBV) and they connote different things. The surface antigen (HbsAg) is the marker of infection and is the first to appear in an infected person. If it persists for longer than 6 months, it signifies chronic hepatitis B. The E-antigen (HbeAg) indicates active replication while the e-antibody (anti-Hbe) generally indicates inactive virus. The appearance of surface antibody (anti-HBs) signifies recovery or immunity so that if an individual has had natural infection which cleared, he/she will have surface antibody. This antibody also develops following hepatitis B vaccine. The hepatitis core antibody (anti-Hbc) indicates present or past infection. When an individual is infected with hepatitis B, they test positive for surface antigen and develop the core antibody. Following recovery, the HbsAg is lost and the surface antibody appears but the core antibody persists. The core antibody appears at the time of infection and persists for life. People who have natural immunity will have both antibodies, the surface antibody (anti-HBs) and the core antibody (anti-HBc) while people who are vaccinated and protected will only have one antibody, the surface antibody (anti-HBs). In general, the following is the interpretation of various markers:a. Hepatitis B surface antigen (HBsAg): Marker of current infection (acute or chronic) b. Hepatitis B surface antibody (anti-HBs): Marker of recovery or immunity (acquired through natural HBV infection, vaccination, or passive antibody immunisation) c. Hepatitis B core antibody (anti-HBc): Marker of present or past infection IgM - indicative of infection in the previous six months IgG - indicative of more distant HBV infection that may have been cleared by the immune system or that may persist; A positive HBsAg and anti-HBc IgG indicates persistent chronic HBV infection d. Hepatitis Be antigen (HBeAg): Marker of active current infection (correlates with a high level of viral replication and is also called a ‘marker of infectivity’ e. Hepatitis Be antibody (anti-HBe): Marker of inactive virus (correlates with low rates of viral replication) f. HBV DNA: Measures virus activity (correlates with active replication) and is useful in monitoring response to treatment of HBV infection