title: The BD FACSPresto Point of Care CD4 Test Accurately Enumerates CD4+ T Cell Counts.
abstract: OBJECTIVE
  Currently 50% of ART eligible patients are not yet receiving life-saving antiretroviral therapy (ART). Financial constraints do not allow most developing countries to adopt a universal test and offer ART strategy. Decentralizing CD4+ T cell testing may, therefore, provide greater access to testing, ART, and better patient management. We evaluated the technical performance of a new point-of-care CD4+ T cell technology, the BD FACSPresto, in a field methods comparison study.
  
  
  METHODS
  264 HIV-positive patients were consecutively enrolled and included in the study. The BD FACSPresto POC CD4+ T cell technology was placed in two rural health care facilities and operated by health care facility staff. We compared paired finger-prick and venous samples using the BD FACSPresto and several existing reference technologies, respectively.
  
  
  RESULTS
  The BD FACSPresto had a mean bias of 67.29 cells/ul and an r(2) of 0.9203 compared to the BD FACSCalibur. At ART eligibility thresholds of 350 and 500 cells/ul, the sensitivity to define treatment eligibility were 81.5% and 77.2% and the specificities were 98.9% and 100%, respectively. Similar results were observed when the BD FACSPresto was compared to the BD FACSCount and Alere Pima. The coefficient of variation (CV) was less than 7% for both the BD FACSCalibur and BD FACSPresto. CD4+ T cell testing by nurses using the BD FACSPresto at rural health care facilities showed high technical similarity to test results generated by laboratory technicians using the BD FACSPresto in a high functioning laboratory.
  
  
  CONCLUSIONS
  The BD FACSPresto performed favorably in the laboratory setting compared to the conventional reference standard technologies; however, the lower sensitivities indicated that up to 20% of patients tested in the field in need of treatment would be missed. The BD FACSPresto is a technology that can allow for greater decentralization and wider access to CD4+ T cell testing and ART.
authors.affiliation: Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Priska
authors.initials: P
authors.lastname: Bwana
authors.affiliation: Clinton Health Access Initiative, Boston, Massachusetts, United States of America.
authors.forename: Lara
authors.initials: L
authors.lastname: Vojnov
authors.affiliation: Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Maureen
authors.initials: M
authors.lastname: Adhiambo
authors.affiliation: Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Catherine
authors.initials: C
authors.lastname: Akinyi
authors.affiliation: Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Joy
authors.initials: J
authors.lastname: Mwende
authors.affiliation: Clinton Health Access Initiative, Boston, Massachusetts, United States of America.
authors.forename: Marta
authors.initials: M
authors.lastname: Prescott
authors.affiliation: Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Matilu
authors.initials: M
authors.lastname: Mwau
mesh_terms: D000328:Adult; D001800:Blood Specimen Collection / Q000379:methods; D018791:CD4 Lymphocyte Count / Q000379:methods; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003430:Cross-Sectional Studies; D003906:Developing Countries; D005260:Female; D015658:HIV Infections / Q000276:immunology; D006679:HIV Seropositivity / Q000276:immunology; D006268:Health Facilities; D006801:Humans; D007753:Laboratories; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems / Q000592:standards*; D011446:Prospective Studies; D012680:Sensitivity and Specificity