A new automated fourth-generation HIV screening assay with sensitive antigen detection module and high specificity

Area of Science:

• Clinical diagnostics
• Immunology

Background:

• Early detection of Human Immunodeficiency Virus (HIV) infection is crucial for patient management and public health.
• Traditional diagnostic methods often have a significant window period between infection and seroconversion, delaying diagnosis.
• Advancements in screening immunoassays aim to shorten this window by detecting viral antigens alongside antibodies.

Purpose of the Study:

• To evaluate the performance of the VIDAS HIV DUO Ultra, a new enzyme-linked fluorescent assay (ELFA).
• To assess its capability for simultaneous detection of HIV antigens and antibodies for early HIV screening.
• To determine the diagnostic window period reduction offered by this fourth-generation assay.

Main Methods:

• Utilized the fully automated VIDAS or mini-VIDAS systems for HIV screening.
• Employed an enzyme-linked fluorescent assay (ELFA) for simultaneous detection of HIV-1 p24 antigen and HIV antibodies.
• Assessed detection limits for HIV-1 p24 antigen (3 pg/mL) and antibody sensitivity comparable to third-generation tests.

Main Results:

• The VIDAS HIV DUO Ultra assay provides simultaneous detection of HIV antigens and antibodies.
• Achieved a detection limit of 3 pg/mL for HIV-1 p24 antigen.
• Demonstrated HIV antibody detection sensitivity equivalent to stand-alone third-generation antibody tests.
• Total incubation time for the assay is approximately 2 hours.
• Automated calculation, interpretation, and printing of results by the VIDAS instrument.

Conclusions:

• The VIDAS HIV DUO Ultra assay effectively reduces the diagnostic window period for HIV infection.
• This automated ELFA offers sensitive and simultaneous detection of HIV antigens and antibodies.
• Appropriate confirmatory testing algorithms are necessary for reactive samples, distinguishing between antigen and antibody reactivity.