Quick Review Cards for Medical Laboratory Science

Appearance of HIV Markers Immunology Review 406

MARKER COMMENTS

Viral RNA Detectable within days of infection.

p24 ag Core coat for nucleic acids. Detectable in 2–3 wk. Becomes undetectable as abs develop, then detectable again in late stages

as immune system fails & virus replicates.

IgM ab Usually detectable in 2–8 wk. Transient. Peaks in about 1–2 wk, undetectable about 1–2 wk later.

IgG ab Detectable shortly after IgM. Gradual ↑in titer over several months. Long lasting.

0 10 20 30 40 50 60 70

Days After Exposure

*By 3rd generation EIA. IgM first, then IgG.

HIV-RNA

HIV p24 Ag

Anti-HIV Ab*

Appearance of HIV markers after exposure (exact times vary with virus, patient immune response, and tests used).