title: Stability of immunophenotypic markers in fixed peripheral blood for extended analysis using flow cytometry.
abstract: The analysis of whole blood samples by flow cytometry for pharmacodynamic and biomarker assessments in clinical studies has been limited by the necessity to test these samples within a short time frame after blood collection. In most clinical studies, blood specimens are shipped to a centralized testing facility; it is critical to demonstrate specimen stability over a period of time which will encompass the time elapsed between specimen collection and testing. A possible solution to overcome this limitation is the use of a fixative to preserve the cell surface antigen stability in whole blood. We examined the stability of markers for T lymphocytes (CD3, CD4, CD8, CD45RA, and CD45RO), B lymphocytes (CD19), NK cells (CD16+CD56), activation (CD25 and HLA-DR), chemokine receptors (CCR5 and CXCR3) and skin homing (CLA) in fixed blood over 7 days and used this information to select the markers for global clinical studies. These assays with selected markers were further validated using fit-for-purpose approach (Lee et al., 2006) and to set the sample acceptability criteria for use in clinical sample testing. Most of the markers examined were stable when collected in Cyto-Chex® BCT for one week with the exception of the activation markers on T cells.
authors.affiliation: Oncology Biomarkers, Centocor R&D, 145 King of Prussia Road, Radnor, PA 19087, USA. cdavis21@its.jnj.com
authors.forename: Cuc
authors.initials: C
authors.lastname: Davis
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Wu
authors.forename: Weimin
authors.initials: W
authors.lastname: Li
authors.forename: Hongtao
authors.initials: H
authors.lastname: Fan
authors.forename: Manjula
authors.initials: M
authors.lastname: Reddy
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D016130:Immunophenotyping / Q000379:methods*; D007694:Killer Cells, Natural / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D013048:Specimen Handling / Q000379:methods*; D018709:Statistics, Nonparametric; D013601:T-Lymphocytes / Q000276:immunology*