Serology of hepatitis b:-




  1. HBsAg—

● Considered to be infected ( can be acute/chronic or carriers)

● Persistence of HBsAg is used to differentiate acute from chronic infection.

●Presence of the antigen longer than 6 months after initial exposure indicates chronic infection.

● Epidemiological marker.

  1. anti-HBs—
    ● Implies either active or passive immunization that usually persists for life.

● Protected.

  1. Anti-HBc—

■ (NOTE:- HbcAg is not detectable in serum)

● first detectable antibody

● IgM anti-HBc indicates acute infection.( most reliable and earliest marker of acute hepatitis infection).

● Only serologic marker detectable during the “window period “ .

● IgG anti-HBc indicates previous or ongoing infection.

  1. HbeAg:-

● High infectivity and active disease.

● Higher rates of viral transmission.

● Marker of viral replication and infectivity. ( HbeAg----produced only during replication of the virus)

  1. anti-HBe:

● It indicates “low infectivity.”

● Loss of HBeAg and appearance of anti-HBe in serum is called “seroconversion”

● Indicates clinical improvement (=remission of the disease).

  1. HBV DNA (quantitative viral load)

● It indicates viral burden and viral replication.

● Assess recovery from infection and candidacy for antiviral therapy.

● To differentiate between inactive carrier state and chronic active hepatitis in chronic HBV infection.

A) Imp info :-

  1. Qualitative marker of HBV-replication-----HbeAg.

  2. Quantitative marker of HBV-replication:-
    Definitive is HBV-DNA >HBV-DNA polymerase

■ Earliest marker of infection ------HBsAg.

■Earliest marker of “Acute Infection”----IgM anti-HBc.



● Refers to HBeAg-negative with normal serum ALT levels and low (< 2000 IU/mL) or undetectable HBV DNA.

■ Precore or Basic core mutant HBV:-

● Also referred to as HBeAg-negative, or anti-HBe-positive HBV.

● HBeAg-negative and anti-HBe-positive patients with high serum HBV-DNA levels (>10000 copies /ml) and persistent or intermittent elevations in alanine aminotransferase (ALT) activity.

● It represents severe and progressive form of liver disease.

● It is associated with frequent development of cirrhosis and HCC.

■ " Hepatitis B “Super carrier” :-

● High titres of HBsAg and HBV-DNA in blood along with HBeAg.
● It indicates early stage of carrier and “highly infectious”.

■ " Hepatitis B “Simple carrier” :-

● Low titre of HBsAg , anti HBe positive, and HBV-DNA negative.

● It indicates late stage of carrier and they will transmit infection when large quantities of blood are transferred.