p24 antigen


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Related to p24 antigen: Western blot

p24 antigen

AIDS The 24 kD core antigen of HIV-1, which is linked to clinical AIDS; p24 is the earliest marker of HIV-1 infection, and detectable days to wks before seroconversion to anti-HIV-1 antibody production, detected by ELISA. See CD4:CD8 ratio, HIV, HIV RNA, Reverse transcriptase, Western blot.

p24 antigen

The core protein of the human immunodeficiency virus (HIV). The presence of p24 antigen in the blood is a marker of uncontrolled HIV replication. p24 antigenemia is encountered in the acute retroviral syndrome before host immune response and in advanced acquired immunodeficiency syndrome when the immune system has been destroyed. When p24 antigen is detected in the blood, the HIV viral load is high and the person is highly infectious.
See also: antigen
References in periodicals archive ?
Now HIV testing begins with a combination assay that detects HIV-1 and HIV-2 antibodies and the HIV-1 p24 antigen.
Viral RNA and p24 antigen as markers of HIV disease and antiretroviral treatment success.
All negative and discordant samples were screened using HIV RNA and HIV p24 antigen tests, and Western blot testing was carried out on all samples where HIV RNA was detected.
8) tested patients in the 3 cohorts for p24 antigen and HIV RNA.
Importantly, no significant differences in HIV RNA plasma (viral load) or p24 antigen levels were seen between the groups over the year of treatment.
The assay is a chemiluminescent microparticle immunoassay (CMIA) for the simultaneous qualitative detection of HIV p24 antigen and antibodies to HIV type 1 (HIV-1 group M and group O) and/ or type 2 (HIV-2) in human serum and plasma (EDTA and heparin).
The SANBS results showed that the Novartis Diagnostics Procleix Ultrio assay identified 6,487 HIV-1-positive units of donated blood, 96 of which were not detected by serology and HIV p24 antigen testing alone.
HIV-1 RNA by polymerase chain reaction (PCR) and p24 antigen were also negative.
Assays for p24 antigen are widely available, relatively inexpensive, and highly specific.
Serologic tests for syphilis, Epstein-Barr virus, and HIV antibody were negative except for a p24 antigen level of 5100 pg/mL.
Additional laboratory steps to reduce HIV infections were implemented by blood banks in 1995 with testing for HIV p24 antigen, which was proposed to shorten the seronegative window to ~20 days (12); the detection rate of donors who are positive for p24 antigen but negative for antibody is several cases per year among ~12 million annual blood donations.