title: Evaluation of performance of human immunodeficiency virus antigen/antibody combination assays in Taiwan.
abstract: BACKGROUND
  The fourth-generation human immunodeficiency virus (HIV) combination assay, which can simultaneously detect the presence of anti-HIV antibody and HIV antigen, has been shown to shorten the window period in HIV diagnosis compared with the third-generation HIV antibody immunoassay. This study was aimed to determine the performance of HIV combination assays in Taiwan, where the HIV-1 seroprevalence is 0.007% and HIV-2 infection has never been reported.
  
  
  METHODS
  Performance of three fourth-generation HIV Ag/Ab combination assays (Dia.Pro, Wantai, and Bio-Rad) and one third-generation HIV Ab immunoassay (AxSYM HIV 1/2 gO) was assessed.
  
  
  RESULTS
  A total of 152 specimens, including 86 confirmed HIV-seropositive and 66 HIV-seronegative samples, were used in the study. The sensitivity of four assays varied from 98.8% to 100%, and specificity varied from 98.5% to 100%. Performance of the 75 equivocal samples, the HIV status of which was confirmed later, in terms of negative prediction varied from 81.8% to 87.5%. The Bio-Rad and Dia.Pro assays exhibited higher sensitivity for the detection of p24 antigen among the three fourth-generation HIV combination assays.
  
  
  CONCLUSIONS
  The three fourth-generation HIV Ag/Ab combination assays exhibited better sensitivity, specificity, and negative prediction than the third-generation HIV Ab immunoassay.
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Chun-Kai
authors.initials: CK
authors.lastname: Chang
authors.affiliation: Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, Taipei, Taiwan.
authors.forename: Cheng-Feng
authors.initials: CF
authors.lastname: Kao
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Pi-Han
authors.initials: PH
authors.lastname: Lin
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Huang
authors.affiliation: Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Shu-Yuan
authors.initials: SY
authors.lastname: Ho
authors.affiliation: Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Kuo-Chen
authors.initials: KC
authors.lastname: Wong
authors.affiliation: Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Bo-Chang
authors.initials: BC
authors.lastname: Lin
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Chang-Ching
authors.initials: CC
authors.lastname: Yeh
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Chia-Yeh
authors.initials: CY
authors.lastname: Lee
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chuan-Liang
authors.initials: CL
authors.lastname: Kao
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chun-Nan
authors.initials: CN
authors.lastname: Lee
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: sychang@ntu.edu.tw.
authors.forename: Sui-Yuan
authors.initials: SY
authors.lastname: Chang
authors.affiliation: Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, Taipei, Taiwan. Electronic address: jyyang@cdc.gov.tw.
authors.forename: Jyh-Yuan
authors.initials: JY
authors.lastname: Yang
mesh_terms: D003955:Diagnostic Tests, Routine / Q000379:methods*; D006678:HIV / Q000276:immunology* / Q000302:isolation & purification*; D015483:HIV Antibodies / Q000097:blood*; D015488:HIV Antigens / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D012680:Sensitivity and Specificity; D013624:Taiwan
chemical_list: D015483:HIV Antibodies; D015488:HIV Antigens
keywords: Taiwan; human immunodeficiency virus; human immunodeficiency virus antibody; human immunodeficiency virus antigen; human immunodeficiency virus combination assay