Mpl cellmek

Phase I was done under ideal laboratory conditions to assess the baseline accuracy and precision of the instrument, compared to the predicate method of CD4 testing in the NHLS. The latter, i.e. FlowCare^™ Panleuco-gated (PLG/CD4) 2-color (CD45 FITC/CD4-RD1) single platform cell enumeration (with addition of Flow Count fluorospheres, Beckman Coulter) [36 (link)–42 (link)]. Testing was done on a Beckman Coulter MPL/CellMek fully automated flow cytometer system using NHLS standardized standard operating procedures (SOPs). Remnant K3EDTA blood was obtained from the CD4 testing laboratory within 24 hours of predicate CD4 testing, and used to manually fill FACSPresto^™ cartridges by pipetting EDTA blood into cartridges (n = 214). Up to ten patient samples (cartridges) were set up simultaneously and incubated at room temperature for 18 minutes before analysis on the instrument, with individual results printed within 2–3 minutes. A subset (n = 115/214) of samples were also tested on a 2nd BD platform (industry standard for small to medium volume CD4 testing), the BD FACSCount^™ system [43 (link)–45 (link)], and the reference Tetrachrome^™ (CD45FITC/CD4-RD1/CD8-ECD/CD3-PC5) T-cell enumeration method on the Beckman Coulter XL flow cytometer [46 (link)].

HIV viral loads were quantified during routine HIV management by the Virology Diagnostic Laboratory, National Health Laboratory Service, using the NucliSens EasyQ HIV-1 assay (BioMe’rieux, Boxtel, Netherlands). CD4+ cell counts were also determined as part of routine HIV treatment by an independent team from the Haematology Diagnostic Laboratory, National Health Laboratory Service using the Beckman Coulter MPL/CellMek fully automated flow-cytometer system (Beckman Coulter, Fullerton, CA, USA).