title: CD4 and CD8 enumeration for HIV monitoring in resource-constrained settings.
abstract: BACKGROUND
  We developed a volumetric single platform image cytometer (SP ICM) that is dedicated to count CD4(+) and CD8(+) T lymphocytes for HIV monitoring in resource-constrained settings. The instrument was designed to be low-cost, yet reliable, easy-to-use, and robust.
  
  
  METHODS
  Whole blood is incubated with CD3-magnetic nanoparticles, CD4-phycoerythrin (PE), and CD8-peridinin-chlorophyll-protein complex (PerCP). The CD3 cells are immunomagnetically attracted to an analysis surface, where fluorescence images of CD4(+) and CD8(+) T lymphocytes are recorded and analyzed, respectively. We compared CD4, CD8 counts, and CD4/CD8 ratio obtained by the SP ICM with those from a SP flow cytometer (FCM) tetraCXP method on blood samples from 145 patients.
  
  
  RESULTS
  Good correlations were obtained (R: 0.96-0.99) between the SP ICM and the SP FCM. There was approximately 10% CD8 undercount in the SP ICM, which could be partly caused by CD8(+dim) T lymphocytes that were not detected by the instrument or not counted by the image analysis due to the cross-talk from the CD4-PE signal in the CD8-PerCP image.
  
  
  CONCLUSIONS
  The SP ICM is a good candidate for HIV monitoring in point-of-care settings of resource-constrained countries.
authors.affiliation: University of Twente, Enschede, The Netherlands.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.forename: Christian
authors.initials: C
authors.lastname: Breukers
authors.forename: Aurel
authors.initials: A
authors.lastname: Ymeti
authors.forename: Björn
authors.initials: B
authors.lastname: Lunter
authors.forename: Leon W M M
authors.initials: LW
authors.lastname: Terstappen
authors.forename: Jan
authors.initials: J
authors.lastname: Greve
mesh_terms: D015704:CD4 Antigens / Q000032:analysis / Q000378:metabolism; D018791:CD4 Lymphocyte Count / Q000379:methods*; D016516:CD4-CD8 Ratio / Q000379:methods*; D016827:CD8 Antigens / Q000032:analysis / Q000378:metabolism; D005434:Flow Cytometry / Q000191:economics / Q000379:methods; D005456:Fluorescent Dyes; D015658:HIV Infections / Q000097:blood* / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D019044:Image Cytometry / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D018189:Immunomagnetic Separation / Q000191:economics / Q000295:instrumentation / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D015166:Monitoring, Immunologic / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D011237:Predictive Value of Tests; D013601:T-Lymphocytes / Q000276:immunology / Q000821:virology
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D005456:Fluorescent Dyes