title: New automated chemiluminescence immunoassay for simultaneous but separate detection of human immunodeficiency virus antigens and antibodies.
abstract: The recently launched Liaison XL Murex HIV Ab/Ag assay (DiaSorin S.p.A) uses chemiluminescence immunoassay technology for the combined qualitative determination of p24 antigen of HIV-1 and specific antibodies to both HIV-1 and HIV-2. We studied 571 serum samples from those submitted to our laboratory for HIV screening. The samples were divided into 3 subsets: subset A, 365 samples collected prospectively during 1 week; subset B, 158 samples from confirmed HIV-positive patients; and subset C, 48 samples with a positive screening result but a negative or indeterminate confirmatory test result. Our standard screening/confirmatory algorithm was used as a reference. In subset A (prospective), 5 samples were positive and 360 negative by the standard procedure. Liaison XL Murex HIV Ab/Ag correctly identified all 5 positive samples (100%) and 357 negative samples (99.2%). In subset B (confirmed positive), all 158 positive samples were in total agreement in both procedures. In subset C (screen positive only), Liaison XL Murex HIV Ab/Ag yielded accurate results in 42 out of 48 samples (87.5%). Global sensitivity and specificity for Liaison XL Murex HIV Ab/Ag (all subsets included) were 98.3% and 98.5%, respectively. Considering only nonselected prospective samples and confirmed positive samples (subsets A and B), the corresponding sensitivity and specificity values were 100% and 99.2%, respectively. The new fully automated HIV screening test showed high sensitivity and specificity compared to our standard algorithm. Its added advantage of being able to detect HIV-1 and HIV-2 antibodies and p24 antigen separately could prove useful in the diagnosis of early infections.
authors.affiliation: Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitário Gregorio Marañón, Madrid, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Alonso
authors.forename: Paula
authors.initials: P
authors.lastname: López Roa
authors.forename: Marisol
authors.initials: M
authors.lastname: Suárez
authors.forename: Emilio
authors.initials: E
authors.lastname: Bouza
mesh_terms: D057205:Automation, Laboratory / Q000379:methods; D015483:HIV Antibodies / Q000097:blood / Q000737:chemistry* / Q000276:immunology; D015488:HIV Antigens / Q000097:blood / Q000737:chemistry* / Q000276:immunology; D016655:HIV Core Protein p24 / Q000097:blood / Q000737:chemistry / Q000276:immunology; D015658:HIV Infections / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D006679:HIV Seropositivity / Q000276:immunology; D015497:HIV-1 / Q000276:immunology; D015498:HIV-2 / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000379:methods; D049449:Luminescence; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
chemical_list: D015483:HIV Antibodies; D015488:HIV Antigens; D016655:HIV Core Protein p24; D011933:Reagent Kits, Diagnostic