title: Analyses of quality assessment studies using CD45 for gating lymphocytes for CD3(+)4(+)%.
abstract: BACKGROUND
  The purpose of this study was to assess whether laboratories which do not use CD45 for gating lymphocytes with three- (or four-) color flow cytometry (non-CD45 laboratories) for CD3(+)4(+)% and CD3(+)8(+)% do worse on quality assessment (QA) studies than laboratories which do use CD45 (CD45 laboratories).
  
  
  METHODS
  Data came from blood specimens donated by 62 donors (50 HIV-positive) assayed over 2 years (November, 1996-October, 1998) by 35 laboratories in the NIAID DAIDS Flow Cytometry QA Program.
  
  
  RESULTS
  Non-CD45 laboratories were significantly more likely to be classified as having unacceptable inter-laboratory results (far from the group median) than CD45 laboratories (5.6% vs 1.5%, P = 0.005 for CD3(+)4(+)%; 10.4% vs 5.0%, P = 0.007 for CD3(+)8(+)%). The intra-laboratory range of results on blinded replicates was significantly more likely to be deemed unacceptable (range >4%) in non-CD45 laboratories than in CD45 laboratories for CD3(+)8(+)% (14. 5% vs 3.5%, P = 0.002) but not for CD3(+)4(+)% (2.6% vs 1.5%, P = 0. 62). These differences in favor of CD45 gating were observed even though the non-CD45 laboratories had been doing three-color flow cytometry in the QA program significantly longer (P = 0.05) than the CD45 laboratories, and so would be expected to have fewer problems with the assay.
  
  
  CONCLUSIONS
  Laboratories which choose to use a single CD3/CD4/CD8 tube for immunophenotyping may be sacrificing both accuracy and reproducibility.
authors.affiliation: Biostatistics Department, Harvard School of Public Health, Boston, Massachusetts, USA. gelman@jimmy.harvard.edu
authors.forename: R
authors.initials: R
authors.lastname: Gelman
authors.forename: C
authors.initials: C
authors.lastname: Wilkening
mesh_terms: D001782:Blood Donors; D017252:CD3 Complex / Q000032:analysis*; D015704:CD4 Antigens / Q000032:analysis*; D016516:CD4-CD8 Ratio; D005434:Flow Cytometry / Q000592:standards* / Q000706:statistics & numerical data; D006679:HIV Seropositivity / Q000276:immunology; D006405:Hematology / Q000592:standards; D006801:Humans; D016130:Immunophenotyping / Q000592:standards*; D007753:Laboratories / Q000592:standards* / Q000706:statistics & numerical data; D017493:Leukocyte Common Antigens / Q000032:analysis*; D018655:Lymphocyte Count / Q000379:methods; D011786:Quality Control; D015203:Reproducibility of Results; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D017252:CD3 Complex; D015704:CD4 Antigens; D017493:Leukocyte Common Antigens