Case 45: Hepatitis in a 30 year old male

Question 1

What does presence of hepatitis B surface antigen (HBsAg) mean?

Answer 1

Found on the surface of the virus but is also produced in vat excess by infected hepatocytes and found in the blood

Question 2

What does presence of hepatitis B surface antibody (HBsAb) mean?

Answer 2

Presence usually indicates immunity

Question 3

What does presence of hepatitis B core antigen (HBcAg) mean?

Answer 3

Protein coat surrounding the viral nucleic acid - current infection

Question 4

What does presence of hepatitis B core antibody (HBcAb) mean?

Answer 4

IgM indicates recent infection, may also be present in reactivations.

IgG will rise in acute infection and persists indefinitely.

Question 5

What does presence of hepatitis B e antigen (HBeAg) mean?

Answer 5

Presence indicates active replication - persists with chronic infection.

Some patients can be HBeAg negative and chronically infected due to a HBV mutant (so-called precore mutant)

Question 6

What does presence of hepatitis B e antibody (HBeAb) mean?

Answer 6

Found only after clearance of HBeAg

Question 7

How can HBV DNA be measured?

Answer 7

By hybridisation assays or PCR

Question 8

The presence of HbsAg, HBV DNA and HBeAg suggests what?

Answer 8

Infection with Hepatitis B

Question 9

How will the antibody profile be different between acute and chronic HBV infection?

Answer 9

Acute: ALT rises and then falls after infection. HBcAb total rises and remains high, HBcAb IgM rises and falls, HBsAb rises, HBeAb rises and then falls

Chronic: ALT rises and falls with intermittent peaks, HBcAb total remains elevated, HBc IgM falls