Could HIV-1 RNA Testing be an Option as the Second Step in the HIV Diagnostic Algorithm?

Area of Science:

• Clinical diagnostics
• Virology
• Infectious diseases

Background:

• Early diagnosis and treatment of HIV-1 infection are vital for patient outcomes.
• Currently, no FDA-approved quantitative assay for HIV-1 diagnosis exists.
• This study evaluates novel diagnostic assays and algorithms for HIV-1 detection.

Purpose of the Study:

• To compare the diagnostic performance of Aptima HIV-1 Quant (APT-Quant) and Aptima HIV-1 Qual (APT-Qual) assays.
• To evaluate a two-test algorithm (Bio-Rad BioPlex 2200 HIV Ag-Ab assay followed by APT-Quant) against a three-test algorithm (BioPlex 2200 followed by Geenius and APT-Qual).

Main Methods:

• Evaluated APT-Quant performance using 524 plasma specimens, including seroconverters and ART-naive individuals.
• Assessed specificity with 200 HIV-negative specimens.
• Compared diagnostic algorithms using McNemar's test for BPC-reactive specimens.

Main Results:

• APT-Quant detected HIV-1 earlier in infection than APT-Qual, with 99.8% specificity.
• Algorithms performed similarly before antiretroviral therapy (ART) initiation.
• The three-test algorithm showed significantly better performance after ART initiation (P = 0.0233).

Conclusions:

• APT-Quant demonstrates excellent performance for HIV-1 diagnostic use.
• The two-test algorithm is effective for ART-naive individuals but less so after ART initiation.
• Further evaluation of the two-test algorithm's implementation factors (cost, specimen type) is needed.