title: Combination assay detecting both human immunodeficiency virus (HIV) p24 antigen and anti-HIV antibodies opens a second diagnostic window.
abstract: Fourth-generation human immunodeficiency virus (HIV) screening immunoassays reduce the diagnostic window between infection and diagnosis by the inclusion of HIV p24 antigen detection together with HIV antibody detection in the same test. We compared third- and fourth-generation HIV immunoassays and a dedicated HIV p24 antigen test for detection of a case of HIV seroconversion. This demonstrated a second diagnostic window using the fourth-generation assay due to a decline of HIV p24 antigen prior to the detection of HIV antibody. However, HIV p24 antigen was detected in the same sample by the dedicated HIV p24 antigen test, as was HIV proviral DNA. Although it is likely to be rare, this phenomenon has also been reported for other fourth-generation HIV immunoassays and has implications for the reported diagnostic windows of these assays.
authors.affiliation: Division of Clinical Microbiology and Infectious Diseases, The Western Australian Centre for Pathology and Medical Research (PathCentre), Hospital Avenue, Nedlands, Western Australia 6009, Australia. david.speers@health.wa.gov.au
authors.forename: David
authors.initials: D
authors.lastname: Speers
authors.forename: Peter
authors.initials: P
authors.lastname: Phillips
authors.forename: John
authors.initials: J
authors.lastname: Dyer
mesh_terms: D015483:HIV Antibodies / Q000097:blood*; D016655:HIV Core Protein p24 / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis* / Q000821:virology; D015497:HIV-1 / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
chemical_list: D015483:HIV Antibodies; D016655:HIV Core Protein p24