Using Exclusion-Based Sample Preparation (ESP) to Reduce Viral Load Assay Cost

PLoS One. 2015 Dec 2;10(12):e0143631. doi: 10.1371/journal.pone.0143631. eCollection 2015.

Abstract

Viral load (VL) measurements are critical to the proper management of HIV in developing countries. However, access to VL assays is limited by the high cost and complexity of existing assays. While there is a need for low cost VL assays, performance must not be compromised. Thus, new assays must be validated on metrics of limit of detection (LOD), accuracy, and dynamic range. Patient plasma samples from the Joint Clinical Research Centre in Uganda were de-identified and measured using both an existing VL assay (Abbott RealTime HIV-1) and our assay, which combines low cost reagents with a simplified method of RNA isolation termed Exclusion-Based Sample Preparation (ESP).71 patient samples with VLs ranging from <40 to >3,000,000 copies/mL were used to compare the two methods. We demonstrated equivalent LOD (~50 copies/mL) and high accuracy (average difference between methods of 0.08 log, R2 = 0.97). Using expenditures from this trial, we estimate that the cost of the reagents and consumables for this assay to be approximately $5 USD. As cost is a significant barrier to implementation of VL testing, we anticipate that our assay will enhance access to this critical monitoring test in developing countries.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • HIV Infections / blood
  • HIV Infections / economics*
  • HIV Infections / virology*
  • HIV Seropositivity
  • HIV-1 / classification
  • HIV-1 / genetics*
  • HIV-1 / isolation & purification
  • Humans
  • Molecular Diagnostic Techniques / economics*
  • Molecular Diagnostic Techniques / methods
  • RNA, Messenger / genetics
  • Reagent Kits, Diagnostic
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Serologic Tests / economics*
  • Serologic Tests / methods
  • Specimen Handling / economics*
  • Viral Load*

Substances

  • RNA, Messenger
  • Reagent Kits, Diagnostic

Grants and funding

Support for this study was provided by the Bill and Melinda Gates Foundation (www.gatesfoundation.org) Global Health Grant Number OPP1028788. SB, HP, JL, DG, AL, AP, and DB received materials and salary support from this grant. EW, CK, PM, and FG received materials support from this grant. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.