Performance of an alternative HIV diagnostic algorithm using the ARCHITECT HIV Ag/Ab Combo assay and potential utility of sample-to-cutoff ratio to discriminate primary from established infection

J Clin Virol. 2013 Dec;58 Suppl 1(0 1):e38-43. doi: 10.1016/j.jcv.2013.08.014. Epub 2013 Aug 26.

Abstract

Background: The ARCHITECT HIV Ag/Ab Combo assay has a wide dynamic range for determining the sample-to-cutoff ratio (S/CO) values compared to other diagnostic HIV antibody assays.

Objectives: Determine the performance of an HIV testing algorithm that uses the ARCHITECT combo assay in the clinical setting and explore the utility of the signal-to-cutoff (S/CO) ratio to predict acute HIV-1 infection status.

Study design: A retrospective analysis of clinical samples from a hospital and referral population screened for HIV-1 infection between May 2011 and March 2013. Repeatedly reactive samples were tested using the Multispot HIV-1/HIV-2 rapid test and depending on that result, confirmatory orthogonal testing used the Western blot (WB) for HIV-1, Immunoblot for HIV-2 and nucleic acid amplification testing (NAAT) for HIV RNA.

Results: A total of 21,317 test results were evaluated of which 509 were ARCHITECT repeatedly reactive; of these, 422 were Multispot-reactive only for HIV-1 (413 WB-positive; 9 indeterminate), 4 were Multispot-reactive for both HIV-1 and HIV-2 (one HIV-2 immunoblot-positive with 17 HIV-2 RNA copies/mL) and 83 were Multispot-non-reactive of which 15 were HIV-1 RNA positive and represented acute HIV-1 infection. There was an association among the ARCHITECT S/CO (median; IQR) values for antibody-negative (0.14; 0.11-0.16), acute infection (33; 2.1-76) and established HIV-1 infection (794; 494-1,029) (Kruskal-Wallis, p<0.0001).

Conclusions: The ARCHITECT combo assay with Multispot confirmation and reserved use of HIV-1 WB, HIV-2 Immunoblot and HIV NAAT for Multispot dual HIV-1/2 infection, and NAAT alone for Multispot-negative specimens, had a suitable test performance for detecting acute and established HIV infection.

Keywords: ARCHITECT HIV Ag/Ab Combo assay; Alternative HIV diagnostic algorithm; Sample-to-cutoff ratio.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Algorithms
  • Diagnostic Tests, Routine / methods*
  • HIV Antibodies / blood*
  • HIV Antigens / blood*
  • HIV Infections / diagnosis*
  • HIV Infections / virology
  • HIV-1 / classification*
  • HIV-1 / genetics
  • HIV-1 / immunology
  • HIV-2 / classification*
  • HIV-2 / genetics
  • HIV-2 / immunology
  • Humans
  • Immunoassay / methods
  • Nucleic Acid Amplification Techniques / methods
  • RNA, Viral / blood*
  • Retrospective Studies
  • Virology / methods

Substances

  • HIV Antibodies
  • HIV Antigens
  • RNA, Viral