title: Single-platform, volumetric, CD45-assisted pan-leucogating flow cytometry for CD4 T lymphocytes monitoring of HIV infection according to the WHO recommendations for resource-constrained settings.
abstract: BACKGROUND
  Validation of new affordable CD4 T cell measurement technologies is crucial specifically in resource-poor countries for antiretroviral treatment eligibility and immunologic CD4 monitoring of HIV-infected patients.
  
  
  METHODS
  The absolute and percentage CD4 T cell counts of 258 HIV-1-infected blood samples (182 adults and 76 children), living in N'Djamena, Chad, were performed by single-platform, volumetric, CD45-assisted pan-leucogating Auto40 flow cytometer (Apogee Flow Systems Ltd, Hemel Hempstead, UK) comparing to the FACSCalibur flow cytometer as a reference method.
  
  
  RESULTS
  Absolute and percentage CD4 T cell counts obtained by Auto40 and FACSCalibur of 258 HIV-1-infected blood samples were highly correlated (r = 0.99 and r = 0.96, respectively). The mean absolute bias and percent bias between Apogee Auto40 and FACSCalibur absolute CD4 T cell counts, were -9.4 cells/μl with limits of agreement from -15 to 93 cells/μl, and +2.0% with limits of agreement from -0.9 to 4.9%, respectively. The mean of absolute bias and percent bias between Apogee Auto40 and FACSCalibur of CD4 percentage results were +0.4% (95% CI: -0.02 - 0.86) with limits of agreement from -2.4 to 0.3%, and +3.0% with limits of agreement from -6.6 to 0.6%, respectively. The Auto40 counting allowed to identify the majority of adults with CD4 T cells below 200 cells/μl (sensitivity: 89%; specificity: 99%) or below 350 cells/μl (sensitivity: 94%; specificity:98%); and of children below 750 cells/μl (sensitivity: 99%; specificity: 96%) or below 25% CD4+ (sensitivity: 94%; specificity: 98%).
  
  
  CONCLUSIONS
  The Auto40 analyzer is an alternative flow cytometer for CD4 T lymphocyte enumeration to be used in routine for immunological monitoring according to the current WHO recommendations in HIV-infected adults as well as children living in resource-constrained settings like Chad.
authors: Ministère de la Santé Publique, N'Djamena BP 407, Chad. koyaltad@yahoo.fr
authors: Donato
authors: D
authors: Koyalta
authors: Mohammad-Ali
authors: MA
authors: Jenabian
authors: Ngamasra
authors: N
authors: Nadjiouroum
authors: Barou
authors: B
authors: Djouater
authors: Noël
authors: N
authors: Djemadji-Oudjeil
authors: Angélique
authors: A
authors: Ndjoyi-Mbiguino
authors: Laurent
authors: L
authors: Bélec
mesh_terms: D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods*; D015658:HIV Infections / Q000097:blood*; D006801:Humans; D017493:Leukocyte Common Antigens / Q000276:immunology*; D008991:Monitoring, Physiologic / Q000379:methods*; D014944:World Health Organization
chemical_list: D017493:Leukocyte Common Antigens
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