title: A rapid manual method for CD4+ T-cell quantitation for use in developing countries.
abstract: OBJECTIVE
  To evaluate a manual method (Cytosphere) for quantifying CD4+ T-cell numbers.
  
  
  METHODS
  Cross-sectional study of HIV-1-seronegative and HIV-1-seropositive individuals evaluated for absolute CD4 counts by both standardized flow cytometric measurements and manual Cytosphere technology using a hemacytometer.
  
  
  METHODS
  University research hospitals in both the United States and Africa.
  
  
  METHODS
  Blood specimens from 382 patients were evaluated. These were broken down into 294 samples obtained from HIV-1-seropositive patients and 88 samples obtained from HIV-1-seronegative patients.
  
  
  METHODS
  None.
  
  
  METHODS
  Absolute CD4 cell number.
  
  
  RESULTS
  Evaluation of samples obtained from HIV-1 patients in both the United States and Africa demonstrated an overall correlation of the Cytosphere assay with flow cytometry of 0.912 (95% confidence interval, 0.895-0.928; P < 0.001). When samples were stratified based on CD4+ T-cell counts determined by flow cytometry, the Cytosphere assay had a 96% predictive value for correctly identifying individuals with CD4 T-cell counts > 200 x 10(6)/l and a 92% predictive value for correctly identifying individuals with CD4 T-cell counts < 200 x 10(6)/l.
  
  
  CONCLUSIONS
  This assay appears to have the potential for the quantitation of CD4 cells in the limited laboratory facilities in developing countries and to have a strong correlation with standard flow cytometric technology.
authors.affiliation: Department of Immunology/Microbiology, Rush-Presbyterian-St Luke's Medical Center, Chicago, Illinois 60612.
authors.forename: A
authors.initials: A
authors.lastname: Landay
authors.forename: J L
authors.initials: JL
authors.lastname: Ho
authors.forename: D
authors.initials: D
authors.lastname: Hom
authors.forename: T
authors.initials: T
authors.lastname: Russell
authors.forename: R
authors.initials: R
authors.lastname: Zwerner
authors.forename: J G
authors.initials: JG
authors.lastname: Minuty
authors.forename: P
authors.initials: P
authors.lastname: Kataaha
authors.forename: F
authors.initials: F
authors.lastname: Mmiro
authors.forename: B
authors.initials: B
authors.lastname: Jackson
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes; D003584:Cytological Techniques; D003906:Developing Countries; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000453:epidemiology / Q000276:immunology / Q000473:pathology*; D006679:HIV Seropositivity / Q000453:epidemiology / Q000276:immunology / Q000473:pathology*; D015497:HIV-1; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D011237:Predictive Value of Tests; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology / Q000473:pathology