Effects of low HIV type 1 load and antiretroviral treatment on IgG-capture BED-enzyme immunoassay.

The IgG-capture BED-enzyme immunoassay (BED-CEIA) is used widely at present to detect recent HIV-1 seroconversion. However, antibody levels and antibody kinetics are impacted by HIV-1 load and antiretroviral treatment, which may have a significant effect on the assay results. In this study, we analyzed serial samples from 11 patients with recent infection, including four patients treated by structured treatment interruption (STI), and compared the results with those of 10 untreated and 7 treated patients with chronic infection. The BED-CEIA missidentified one long-term nonprogressor hemophiliac with an extremely low HIV-1 load and five patients with chronic infection who received antiretroviral treatment. We also found that the ODn values increased slowly in patients with recent infection and low HIV-1 loads and that the ODn values fluctuated in parallel with HIV-1 load during STI. Our data indicate that the results of BED-CEIA are influenced by HIV-1 load and antiretroviral treatment. Care should be taken when interpreting the results of BED-CEIA, especially in individuals with low HIV-1 loads. Those on antiretroviral treatment should be excluded from BED-CEIA testing to improve the predictive value of detecting recent infections.