Performance evaluation of a new fourth-generation HIV combination antigen–antibody assay

Abstract

Education and diagnostic tests capable of early detection represent our most effective means of preventing transmission of human immunodeficiency virus (HIV). The importance of early detection is underlined by studies demonstrating increased life expectancy following early initiation of antiviral treatment. The Elecsys® HIV combi PT assay is a fourth-generation antigen–antibody combination assay developed to allow earlier detection of seroconversion, and to have increased sensitivity and improved specificity. We aimed to determine how early the assay could detect infection compared with existing assays; whether all HIV variants could be detected; and the assay’s specificity using samples from blood donors, routine specimens, and patients with potential cross-reacting factors. Samples were identified as positive by the Elecsys® assay 4.9 days after a positive polymerase chain reaction result (as determined by the panel supplier), which was earlier than the 5.3–7.1 days observed with comparators. The analytical sensitivity of the Elecsys® HIV combi PT assay for the HIV-1 p24 antigen was 1.05 IU/mL, which compares favorably with the comparator assays. In addition, the Elecsys® assay identified all screened HIV subtypes and displayed greater sensitivity to HIV-2 homologous antigen and antibodies to HIV-1 E and O and HIV-2 than the other assays. Overall, the specificity of the Elecsys® assay was 99.88 % using samples from blood donors and 99.81 % when analyzing unselected samples. Potential cross-reacting factors did not interfere with assay performance. The Elecsys® HIV combi PT assay is a sensitive and specific assay that has been granted the CE mark according to Directive 2009/886/EC.

Clinical Evaluation of BioPlex 2200 HIV Ag-Ab, an Automated Screening Method Providing Discrete Detection of HIV-1 p24 Antigen, HIV-1 Antibody, and HIV-2 Antibody

“…For 30 years, remarkable progress has been made in the development of tools for HIV detection. HIV combo assays, also referred to as fourth-generation assays, detect both HIV-1 and HIV-2 antibodies (Ab) and the HIV-1 p24 antigen (Ag) which reduces, compared to third-generation assays, the window period to an average of 2 weeks (4)(5)(6)(7)(8)(9)(10)(11)(12).…”

New Automated Chemiluminescence Immunoassay for Simultaneous but Separate Detection of Human Immunodeficiency Virus Antigens and Antibodies

“…Due to their ability to detect HIV p24 Ag, these tests can detect HIV infection prior to seroconversion (3). The sensitivity of fourth-generation assays for the detection of early HIV infection has been proven in several prior studies (4)(5)(6)(7)(8)(9).…”

Humanes Immunschwächevirus (HIV)

“…Singuläre p24-Antigenteste oder kombinierte Antigen/Antikörperteste (sog 4. Generationsteste) sind zugelassen und kommerziell erhält-lich [114,119].…”