Hepatitis Serology

Question 1

HBsAg

Answer 1

Hepatitis B surface antigen
Marker of viral replication and thus ACTIVE infection

First antibody to appear and triggers production of anti HBS

Question 2

When does HbsAg appear and disappear by?

Answer 2

appears within 6 weeks of infection, disappears by 3 months after

Question 3

What does HbsAg imply?

Answer 3

Acute disease (1-6 months)

Question 4

What does HbsAg presence for >6 months imply?

Answer 4

if HBsAg is present for > 6 months then this implies chronic disease (i.e. Infective)

Question 5

Anti-Hb

or HbsAB

Answer 5

anti-hepatitis B surface antibody

Marker of previously cleared infection / vaccination
(either exposure or immunisation). It is negative in chronic disease

Question 6

HbeAg

Answer 6

HbeAg results from breakdown of core antigen from infected liver cells as is, therefore, a marker of infectivity

Question 7

HBeAb

Answer 7

Natural immunity to hep B

Question 8

Anti Hbc

Answer 8

Anti-HBc implies previous (or current) infection. IgM anti-HBc appears during acute or recent hepatitis B infection and is present for about 6 months. IgG anti-HBc persists