A pilot evaluation of whole blood finger-prick sampling for point-of-care HIV viral load measurement: the UNICORN study

Sci Rep. 2017 Oct 20;7(1):13658. doi: 10.1038/s41598-017-13287-2.

Abstract

There is a global need for HIV viral load point-of-care (PoC) assays to monitor patients receiving antiretroviral therapy. UNICORN was the first study of an off-label protocol using whole blood finger-prick samples tested with and without a simple three minute spin using a clinic-room microcentrifuge. Two PoC assays were evaluated in 40 HIV-positive participants, 20 with detectable and 20 with undetectable plasma viral load (pVL) (<20 copies/ml). Using 100 µl finger-prick blood samples, the Cepheid Xpert HIV-1 Viral Load and HIV-1 Qual cartridges were compared with laboratory pVL assessment (TaqMan, Roche). For participants with undetectable viraemia by TaqMan, there was poor concordance without centrifugation with the TaqMan platform with only 40% 'undetectable' using Xpert VL and 25% 'not detected' using the Qual assay. After a 3 minute spin, 100% of samples were undetectable using either assay, showing full concordance with the TaqMan assay. Defining a lower limit of detection of 1000 copies/ml when including a spin, there was 100% concordance with the TaqMan platform with strong correlation (rho 0.95 and 0.94; p < 0.0001 for both assays). When including a simple microcentrifugation step, finger-prick PoC testing was a quick and accurate approach for assessing HIV viraemia, with excellent concordance with validated laboratory approaches.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Blood Specimen Collection* / methods
  • Centrifugation
  • Female
  • HIV Infections / blood*
  • HIV Infections / virology*
  • HIV-1*
  • Humans
  • Male
  • Middle Aged
  • Pilot Projects
  • Point-of-Care Testing*
  • Viral Load* / instrumentation
  • Viral Load* / methods
  • Young Adult