Validation for clinical use of a novel HIV-2 plasma RNA viral load assay using the Abbott m2000 platform

J Clin Virol. 2012 Oct;55(2):128-33. doi: 10.1016/j.jcv.2012.06.024. Epub 2012 Jul 24.

Abstract

Background: Optimal care of persons infected with human immunodeficiency virus type 2 (HIV-2) requires an accurate assessment of HIV-2 plasma viral load (VL), but no clinically approved quantitative HIV-2 RNA VL assay exists.

Objectives: To validate a novel quantitative HIV-2 RNA assay for clinical and research use.

Study design: The Abbott m2000sp/rt platform was adapted for quantification of HIV-2 RNA in plasma. Amplification targeted a region of the long terminal repeat conserved in Group A and B HIV-2. Electron microscopy-counted-HIV-2 standards, the WHO/NIBSC HIV-2 International Standard and clinical specimens (N=162) were used to determine the precision, sensitivity, specificity, linear range, accuracy, and clinical performance of the assay.

Results: The quantitative linear range of the HIV-2 RNA assay was 10-1,000,000 copies/mL (R(2)>0.99), with a limit of detection of 8 copies/mL (95% CI, 5-18 copies/mL). The assay did not cross-react with HIV-1, and quantification of HIV-2 RNA was not affected by the presence of >5 log(10)HIV-1 RNA copies/mL. The total standard deviation (SD) and intra- and inter-run SD were 0.095, 0.093 and 0.162, respectively, at nominal inputs of 3.7, 1.7 and 1.0 log(10)HIV-2 RNA copies/mL. The HIV-2 WHO/NIBSC International Standard (1000 IU) was shown to contain 152 RNA copies/mL (95% CI 141-163). Overall, HIV-2 RNA was quantified at ≥10 copies/mL from 86 (53%) clinical specimens (median, 2.24 log(10) copies/mL; range 10-16,870), and nine specimens (6%) had HIV-2 RNA detected at <10 copies/mL.

Conclusions: We developed and validated a highly sensitive HIV-2 VL assay that is suitable for clinical and research use.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • HIV Infections / virology*
  • HIV-2 / isolation & purification*
  • Humans
  • Plasma / virology*
  • RNA, Viral / blood*
  • Sensitivity and Specificity
  • Viral Load / methods*

Substances

  • RNA, Viral