The variable sensitivity of HIV Ag/Ab combination assays in the detection of p24Ag according to genotype could compromise the diagnosis of early HIV infection

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

“…An advantage over previous fourth-generation assays is that it detects and reports separate values for HIV antigens and antibodies, thus enabling better interpretation of results. The performance of this new assay for the screening of HIV infection has not been extensively evaluated (10,11).…”

Performance of the Liaison XL Murex HIV Ab/Ag Test on Clinical Samples Representing Current Epidemic HIV Variants

“…S ince the discovery of HIV, many tests have been marketed for the diagnosis of HIV infection, and the performance of these tests has been extensively evaluated (1)(2)(3). First-, second-, and third-generations assays, which detect only antibodies against HIV, lack the sensitivity to detect primary infections and may fail to detect recent non-B subtype infections or divergent variants (1,4).…”

“…First-, second-, and third-generations assays, which detect only antibodies against HIV, lack the sensitivity to detect primary infections and may fail to detect recent non-B subtype infections or divergent variants (1,4). Fourth-generation tests, which detect antibodies against both the virus and the viral antigen p24, are now recommended in France and elsewhere (5,6) due to their great potential for detecting early infections.…”

“…A new 4th-generation assay, the DiaSorin (Saluggia, Italy) Liaison XL Murex HIV Ab/Ag (Liaison XL), was recently developed. However, few studies have investigated the performance of this assay (1,13,14), and no data are available about its ability to recognize different HIV variants, except for data about the p24 antigen (1).…”

Large-Scale Analysis of the Prevalence and Geographic Distribution of HIV-1 Non-B Variants in the United States

“…Natural polymorphisms occurring within primer and/or probe binding sites can result in underquantitation or lack of detection in molecular assays designed for viral load measurement and blood screening (9,(12)(13)(14)(15)(16). Similarly, polymorphisms that modify or ablate key epitopes can compromise the performance of serological diagnostic and screening assays (7,17). Although subtype B infections represent only 11% of HIV-1 infections worldwide (4), most serological and molecular assays and controls (including the WHO International Standard) have been developed and optimized utilizing subtype B strains.…”