Study on the Technical Parameters for Estimating HIV-1 Incidence by Using a Recombinant Antigen-based Capture Enzyme...

Area of Science:

• Immunology
• Virology
• Epidemiology

Background:

• Accurate estimation of human immunodeficiency virus type 1 (HIV-1) incidence is crucial for public health surveillance.
• Existing methods for incidence estimation require optimization for specific populations and regions.

Purpose of the Study:

• To optimize a novel recombinant antigen-based capture enzyme immunoassay (RAg-CEIA) for technical parameters.
• To evaluate the RAg-CEIA's performance in differentiating recent from long-term HIV-1 infections in China.
• To enable reliable HIV-1 incidence estimation using the optimized assay.

Main Methods:

• Orthogonal experimental design was used to optimize RAg-CEIA raw material dilution ratios.
• Normalized optical density (ODn) values were measured in longitudinal plasma specimens from HIV-1 seroconverting individuals.
• The optimal ODn threshold, mean duration of recent infection (MDRI), and false recent rate (FRR) were determined.

Main Results:

• Optimal RAg-CEIA parameters included a 1/12 calibrator dilution ratio and a 1:1200 enzyme conjugate titer.
• ODn values showed temporal increases in seroconverters, with individual kinetic heterogeneity.
• An ODn threshold of 0.8 corresponded to an MDRI of 205 days and an FRR of 4.78%.

Conclusions:

• The optimized RAg-CEIA effectively differentiates recent from long-term HIV-1 infections.
• This assay provides a reliable tool for estimating HIV-1 incidence in the Chinese population.
• The findings support the use of RAg-CEIA for HIV-1 surveillance in China.