Which antigen is used in 4th-generation HIV tests that allows for earlier detection compared to antibody-only tests?

Which antigen is used in 4th-generation HIV tests that allows for earlier detection compared to antibody-only tests?

• A. gp120
• B. p24 antigen
• C. gp41
• D. HLA antigen

Answer: (B)

The p24 antigen is a core protein of the HIV virus that can be detected in the blood during the early phase of HIV infection. This early detection capability is a significant advantage of 4th-generation HIV tests compared to older antibody-only tests. In the initial stages of HIV infection, antibodies to the virus take time to develop, usually several weeks. However, the p24 antigen can be present in the blood as soon as 2 to 3 weeks after infection, which allows for earlier diagnosis. The testing method combines detection of both antibodies and the p24 antigen, leading to a more immediate identification of HIV infection. While gp120 and gp41 are also proteins associated with HIV, they are primarily recognized by the body's immune response as antibodies develop; therefore, they are not as effective for early detection. HLA antigens, on the other hand, are related to immune response but are not specific to HIV and are not used in these tests. Thus, p24 antigen detection is vital for timely diagnosis and management of HIV.

The p24 antigen is a core protein of the HIV virus that can be detected in the blood during the early phase of HIV infection. This early detection capability is a significant advantage of 4th-generation HIV tests compared to older antibody-only tests.

In the initial stages of HIV infection, antibodies to the virus take time to develop, usually several weeks. However, the p24 antigen can be present in the blood as soon as 2 to 3 weeks after infection, which allows for earlier diagnosis. The testing method combines detection of both antibodies and the p24 antigen, leading to a more immediate identification of HIV infection.

While gp120 and gp41 are also proteins associated with HIV, they are primarily recognized by the body's immune response as antibodies develop; therefore, they are not as effective for early detection. HLA antigens, on the other hand, are related to immune response but are not specific to HIV and are not used in these tests. Thus, p24 antigen detection is vital for timely diagnosis and management of HIV.