title: Performance comparison of the 4th generation Bio-Rad Laboratories GS HIV Combo Ag/Ab EIA on the EVOLIS™ automated system versus Abbott ARCHITECT HIV Ag/Ab Combo, Ortho Anti-HIV 1+2 EIA on Vitros ECi and Siemens HIV-1/O/2 enhanced on Advia Centaur.
abstract: BACKGROUND
  A multisite study was conducted to evaluate the performance of the Bio-Rad 4th generation GS HIV Combo Ag/Ab EIA versus Abbott 4th generation ARCHITECT HIV Ag/Ab Combo. The performance of two 3rd generation EIAs, Ortho Diagnostics Anti-HIV 1+2 EIA and Siemens HIV 1/O/2 was also evaluated.
  
  
  OBJECTIVE
  Study objective was comparison of analytical HIV-1 p24 antigen detection, sensitivity in HIV-1 seroconversion panels, specificity in blood donors and two HIV false reactive panels.
  
  
  METHODS
  Analytical sensitivity was evaluated with International HIV-1 p24 antigen standards, the AFFSAPS (pg/mL) and WHO 90/636 (IU/mL) standards; sensitivity in acute infection was compared on 55 seroconversion samples, and specificity was evaluated on 1000 negative blood donors and two false reactive panels.
  
  
  RESULTS
  GS HIV Combo Ag/Ab demonstrated better analytical HIV antigen sensitivity compared to ARCHITECT HIV Ag/Ab Combo: 0.41 IU/mL versus 1.2 IU/mL (WHO) and 12.7 pg/mL versus 20.1 pg/mL (AFSSAPS); GS HIV Combo Ag/Ab EIA also demonstrated slightly better specificity compared to ARCHITECT HIV Ag/Ab Combo (100% versus 99.7%). The 4th generation HIV Combo tests detected seroconversion 7-11 days earlier than the 3rd generation HIV antibody only EIAs.
  
  
  CONCLUSIONS
  Both 4th generation immunoassays demonstrated excellent performance in sensitivity, with the reduction of the serological window period (7-11 days earlier detection than the 3rd generation HIV tests). However, GS HIV Combo Ag/Ab demonstrated improved HIV antigen analytical sensitivity and slightly better specificity when compared to ARCHITECT HIV Ag/Ab Combo assay, with higher positive predictive values (PPV) for low prevalence populations.
authors.affiliation: Bio-Rad Laboratories, 6565 185th Avenue NE, Redmond, WA 98052, United States. Electronic address: Elizabeth_mitchell@bio-rad.com.
authors.forename: Elizabeth O
authors.initials: EO
authors.lastname: Mitchell
authors.affiliation: Bio-Rad Laboratories, 4000 Alfred Nobel Drive, Hercules, CA 94547, United States.
authors.forename: Greg
authors.initials: G
authors.lastname: Stewart
authors.affiliation: Bio-Rad Laboratories, 6565 185th Avenue NE, Redmond, WA 98052, United States.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bajzik
authors.affiliation: Bio-Rad Laboratories, 3 Boulevard Raymond Poincare, Marnes La Coquette 92430, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Ferret
authors.affiliation: Bio-Rad Laboratories, 6565 185th Avenue NE, Redmond, WA 98052, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Bentsen
authors.affiliation: Bio-Rad Laboratories, 6565 185th Avenue NE, Redmond, WA 98052, United States.
authors.forename: M Kathleen
authors.initials: MK
authors.lastname: Shriver
mesh_terms: D057205:Automation, Laboratory / Q000379:methods*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005189:False Positive Reactions; D015483:HIV Antibodies / Q000097:blood*; D015488:HIV Antigens / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods
chemical_list: D015483:HIV Antibodies; D015488:HIV Antigens
keywords: 4th Generation; AFSSAPS; Ab; Ag/Ab combination; Agence Francaise de sécurité sanitaire des produits de santé; CI; EIA; FDA; False positives; Food and Drug Administration; IRB; IU; Institutional Review Board; PCR; PPV; RNA; S/CO; Specificity; WHO; World Health Organization; antibody; confidence interval; enzyme immunoassay; glycoprotein; gp; international unit; mL; milliliter; p-NAAT; pg; picogram; polymerase chain reaction; pooled nucleic acid amplification tests; positive predictive value; ribonucleic acid; signal to cut-off