title: Using Exclusion-Based Sample Preparation (ESP) to Reduce Viral Load Assay Cost.
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.
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Berry
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America.
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Pezzi
authors.affiliation: Joint Clinical Research Centre; Kampala, Uganda.
authors.forename: Eram D
authors.initials: ED
authors.lastname: Williams
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Loeb
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America.
authors.forename: David J
authors.initials: DJ
authors.lastname: Guckenberger
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America.
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Lavanway
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America.
authors.forename: Alice A
authors.initials: AA
authors.lastname: Puchalski
authors.affiliation: Joint Clinical Research Centre; Kampala, Uganda.
authors.forename: Cissy M
authors.initials: CM
authors.lastname: Kityo
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Mugyenyi
authors.affiliation: Joint Clinical Research Centre; Kampala, Uganda.
authors.forename: Franklin M
authors.initials: FM
authors.lastname: Graziano
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States of America.
authors.forename: David J
authors.initials: DJ
authors.lastname: Beebe
mesh_terms: D015658:HIV Infections / Q000097:blood / Q000191:economics* / Q000821:virology*; D006679:HIV Seropositivity; D015497:HIV-1 / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000191:economics* / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics; D011933:Reagent Kits, Diagnostic; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012698:Serologic Tests / Q000191:economics* / Q000379:methods; D013048:Specimen Handling / Q000191:economics*; D019562:Viral Load
chemical_list: D012333:RNA, Messenger; D011933:Reagent Kits, Diagnostic