Hepatitis B surface antibody (Anti-HBs)
Hepatitis B virus has special proteins known as antigens (HBsAg) on its surface. When the virus infects a person, hepatitis B surface antibodies (anti-HBs) are produced against the surface antigens in the individual’s body. The antibodies are also produced in response to vaccination. The hepatitis B surface antibody test measures the anti-HBs and determines the immune status of the infected person. It also helps in identifying any previous exposure to the virus.
Why is the test ordered?
The test may be ordered to determine the strength of the immune system of an individual who has been exposed to the virus. It also helps in identifying any previous exposure to the hepatitis B virus.
When is the test ordered?
The test may be ordered by a physician if he wants to determine the strength of the immune system of an individual in order to determine the status of his general health. Such individuals include health care professionals who have come in contact with the body fluids of an infected patient, patients receiving immunotherapy, patients undergoing haemodialysis and babies born to HBsAg positive mothers and sex partners who tested positive for hepatitis B.
How is the sample collected?
A blood sample is collected from a vein in the arm.
How to prepare for the test?
No special preparations are required for this test.