title: Evaluation of the blood stabilizers TransFix and Cyto-Chex BCT for low-cost CD4 T-cell methodologies.
abstract: TransFix(TM) and Cyto-Chex((R)) BCT (blood collection tube) reagents have been shown to maintain whole blood integrity for delayed immunophenotyping by flow cytometry. We evaluated the ability of these blood-stabilizing reagents to preserve HIV-seropositive blood for delayed CD4(+) T-cell quantification utilizing the Dynal((R)) Biotech T4 Quant Kit. TransFix was added to EDTA-anticoagulated whole blood and tested at a 1:10 dilution over 7 d using the Dynal (n = 21) manual method. Compared to baseline analysis, a significant decrease in mean CD4(+) counts was observed over time. Cyto-Chex BCT-preserved samples (n = 20) were tested for CD4(+) counts by Dynal over 7 d, with storage at varying temperatures: room temperature (21 degrees C), 37 degrees C, and 37 degrees C with intermittent storage at 42 degrees C. A significant decline in mean CD4(+) counts was observed in samples at all temperatures compared to baseline (p < 0.05). Increases in temperature to and above 37 degrees C resulted in a greater decline in mean CD4(+) counts over time. Our findings indicated that neither TransFix or Cyto-Chex BCT was a suitable blood stabilizer when used for delayed CD4(+) quantification with a low-cost manual CD4(+) bead-based method.
authors.affiliation: 1 AIDS Pathogenesis and Clinical Research Program, Burnet Institute for Medical Research and Public Health, Melbourne, Australia.
authors.forename: Megan M
authors.initials: MM
authors.lastname: Plate
authors.forename: Raul
authors.initials: R
authors.lastname: Louzao
authors.forename: Pauline M
authors.initials: PM
authors.lastname: Steele
authors.forename: Vicki
authors.initials: V
authors.lastname: Greengrass
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Morris
authors.forename: Jenny
authors.initials: J
authors.lastname: Lewis
authors.forename: David
authors.initials: D
authors.lastname: Barnett
authors.forename: Dominic
authors.initials: D
authors.lastname: Warrino
authors.forename: Anna C
authors.initials: AC
authors.lastname: Hearps
authors.forename: Thomas
authors.initials: T
authors.lastname: Denny
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Crowe
mesh_terms: D001793:Blood Preservation / Q000191:economics / Q000295:instrumentation*; D018791:CD4 Lymphocyte Count / Q000191:economics / Q000295:instrumentation*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D005434:Flow Cytometry; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D011933:Reagent Kits, Diagnostic / Q000191:economics*; D013696:Temperature
chemical_list: D011933:Reagent Kits, Diagnostic