Detection of individuals with acute HIV-1 infection using the ARCHITECT HIV Ag/Ab Combo assay.

BACKGROUND

We evaluated use of the ARCHITECT HIV Ag/Ab Combo assay (HIV Combo; Abbott Diagnostics; available for sale outside the United States only) for detection of acute HIV infection.

METHODS

Samples were obtained from a behavioral intervention study (EXPLORE). HIV-uninfected men who have sex with men were enrolled and tested for HIV infection every 6 months. Samples from seroconverters collected at their last seronegative visit (n = 217) were tested individually using 2 HIV RNA assays. Samples with detectable HIV RNA were classified as acute and were tested with HIV Combo. Samples from the enrollment visit (n = 83) and the time of HIV seroconversion (n = 219) were tested with HIV Combo as controls.

RESULTS

Twenty-one samples (9.7%) from the last seronegative visit had detectable HIV RNA and were classified as acute. HIV Combo was positive for 13 of the acute samples (61.9%). Samples not detected by HIV Combo had viral loads of 724-15,130 copies per milliliter. Expected results were obtained for positive and negative controls tested with HIV Combo.

CONCLUSIONS

HIV Combo detected nearly two thirds of acute HIV infections identified in this high-risk population by non-pooled HIV RNA assays. HIV Combo may be useful for high-throughput screening to identify individuals with acute HIV infection.