- Last Update On : 2013-01-20
The presence of HIV-1 viral antigens provides direct evidence of infection. The p24 viral core antigen, a protein that surrounds viral nucleic acid, can often be detected two weeks after infection. Subsequently, p24 antibody is produced and complexes with soluble p24 antigen, rendering it undetectable. Antigen reappears later in the course of the illness as p24 antibody levels decline.
There appears to be a direct association between HIV-1 antigenemia and the likelihood of progressing to AIDS. During a three-year study, only 15% of HIV antigen negative homosexual males progressed to AIDS, compared to 59% of antigen positive males. Mean duration of antigenemia before development of AIDS is 60 weeks (range 9-82 weeks). Approximately 10 to 20% of asymptomatic HIV infected homosexual males have chronic HIV antigenemia with a rapidly progressive clinical course.
Results are reported as positive or negative. Reference value is negative.
Specimen requirement is one SST tube of blood.