title: Leukodepletion as a point-of-care method for monitoring HIV-1 viral load in whole blood.
abstract: In order to limit the interference of HIV-1 cellular nucleic acids in estimating viral load (VL), the feasibility of leukodepletion of a small whole-blood (WB) volume to eliminate only leukocyte cell content was investigated, using a selection of filters. The efficacy of leukocyte filtration was evaluated by counting, CD45 quantitative PCR, and HIV-1 DNA quantification. Plasma HIV-1 was tested by real-time reverse transcription (RT)-PCR. A specific, miniaturized filter was developed and tested for leukocyte and plasma virus retention, WB sample dilution, and filtration parameters in HIV-1-spiked WB samples. This device proved effective to retain >99.9% of white blood cells in 100 μl of WB without affecting plasma VL. The Samba sample preparation chemistry was adapted to use a leukodepleted WB sample for VL monitoring using the point-of-care Samba-1 semiautomated system. The clinical performance of the assay was evaluated by testing 207 consecutive venous EDTA WB samples from HIV-1-infected patients attending a CD4 testing clinic. Most patients were on antiretroviral treatment (ART), but their VL status was unknown. Compared to the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 test, the new Samba assay had a concordance of 96.5%. The use of the Samba system with a VL test for WB might contribute to HIV-1 ART management and reduce loss-to-follow-up rates in resource-limited settings.
authors.affiliation: Diagnostic Development Unit, Department of Haematology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Logan
authors.initials: L
authors.lastname: Titchmarsh
authors.affiliation: U.S. Centers for Disease Control and Prevention, HIV-Research Branch, Kisumu, Kenya, and Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Clement
authors.initials: C
authors.lastname: Zeh
authors.affiliation: Macopharma, Department of Research and Development, Tourcoing, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Verpoort
authors.affiliation: Division of Transfusion Medicine, Department of Haematology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Allain
authors.affiliation: Diagnostic Development Unit, Department of Haematology, University of Cambridge, Cambridge, United Kingdom hl207@cam.ac.uk.
authors.forename: Helen
authors.initials: H
authors.lastname: Lee
mesh_terms: D002469:Cell Separation / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D007962:Leukocytes / Q000821:virology*; D019095:Point-of-Care Systems; D019562:Viral Load / Q000379:methods*