Improved detection of HIV p24 antigen in serum after acid pretreatment

Abstract

HIV-1 p24 antigen was detected in 554 sera (509 from HIV-1 seropositive individuals and 45 sera from seronegative controls) using a conventional method with acid pretreatment of the sample in order to separate the p24 antigen/anti-p24 antibody immune complexes. In asymptomatic individuals there was a substantial increase in antigen detection (48.2% vs 8.4%). Similar results were also observed in ARC (59.1% vs 12.2%) and AIDS patients (85.7% vs 37.1%). It can be concluded that the acid treatment improves the sensitivity of conventional techniques to detect HIV-1 p24 antigen.

Measurement of human immunodeficiency virus type 1 p24 in serum by an ultrasensitive enzyme immunoassay, the two-site immune complex transfer enzyme immunoassay

“…The detection rates of p24 in the sera of HIV-1-seropositive individuals by the conventional two-site enzyme immunoassays were lower than those by the present enzyme immunoassay. The detection rates by the conventional two-site enzyme immunoassays before and after acid treatment of serum were 8 to 10% (4,17,21) and 38 to 48% (17,21), respectively, for asymptomatic carriers, 12% (21) and 59% (21), respectively, for patients with ARC, and 37 to 86% (4,15,21) and 86% (21), respectively, for patients with AIDS. By the present enzyme immunoassay, the detection rate for the asymptomatic carriers was 48% before acid treatment and improved to 68% with acid treatment, and the detection rates for the patients with ARC and AIDS were 78 and 90%, respectively, with no improvement with acid treatment.…”

“…However, the rate of detection of p24 in serum and plasma is rather low. By the conventional two-site enzyme immunoassays with as much as 100 to 200 l of serum or plasma, p24 has been detected in 8 to 10 and 38 to 48% of asymptomatic carriers before and after acid treatment of serum or plasma, respectively (4,15,17,21). This is at least partly due to the low levels of sensitivity of the methods used (10 to 50 pg/ml) (2, 4, 13, 15-17, 19, 21, 25, 26).…”