Comparison of interlaboratory variation in absolute T‐cell counts by single‐platform and optimized dual‐platform methods
Open Access
- 7 October 2009
- journal article
- research article
- Published by Wiley in Cytometry Part B: Clinical Cytometry
- Vol. 78B (3), 194-200
- https://doi.org/10.1002/cyto.b.20500
Abstract
Background: Previous studies have reported that the adoption of a single‐platform flow cytometry cell counting method resulted in lower interlaboratory variation in absolute T cell counts as compared to predicate dual‐platform flow cytometry methods which incorporate independent automated lymphocyte counts (Schnizlein‐Bick et al., Clin Diagn Lab Immunol 2000;7:336–343; Reimann et al., Clin Diagn Lab Immunol 2000;7:344–351). In the present study, we asked whether use of a single‐platform method could reduce variation in absolute cell counts across the laboratories in the Multicenter AIDS Cohort Study (MACS) (n = 4), as suggested by the studies cited. Methods: Identical study samples were shipped overnight to the MACS laboratories either by the National Institute of Allergy and Infectious Diseases, Division of AIDS Immunology Quality Assessment (NIAID‐ IQA) proficiency‐testing program (n = 14), or by the Los Angeles site of the MACS (n = 10). For each sample, two tubes of blood were received; one was used for an automated complete blood count and differential, and the other for flow cytometry. The latter was performed using both our current dual‐platform method (three‐color CD45 gating and automated hematology) and the single‐platform method (with TruCOUNT® beads to generate the absolute counts). Results: The median percent coefficients of variation (%CVs) for the dual‐platform and single‐platform methods were 6.6 and 9.9, respectively, for CD4 T cell counts, and 5.9 and 8.5, respectively, for CD8 T cell counts (n = 24). These differences were not statistically significant. The differences in absolute T‐cell counts between the MACS sites and the median of all laboratories participating in the NIAID‐IQA were smaller for the dual‐platform than for single‐platform absolute count method. Conclusion: In contrast to previous reports, we did not observe lower interlaboratory variation across the MACS sites for single‐platform absolute lymphocyte subset counting relative to dual‐platform methods. This result may be at least partly explained by the lower interlaboratory variation with the optimized dual‐platform method in this study relative to the previous reports. © 2009 Clinical Cytometry SocietyThis publication has 17 references indexed in Scilit:
- CD4 T cell measurements in the management of antiretroviral therapy-A review with an emphasis on pediatric HIV-infected patientsCytometry Part B: Clinical Cytometry, 2008
- Evaluation of a Simplified Dual-Platform Flow Cytometric Method for Measurement of Lymphocyte Subsets and T-Cell Maturation Phenotypes in the Population of Nouna, Burkina FasoClinical and Vaccine Immunology, 2007
- Assessing immunophenotyping performance: Proficiency‐validation for adopting improved flow cytometry methodsCytometry Part B: Clinical Cytometry, 2007
- Flow Cytometry-Based Immunophenotyping Method and ApplicationsPublished by American Society for Microbiology ,2006
- Risk of progression to AIDS and death in women infected with HIV-1 initiating highly active antiretroviral treatment at different stages of disease.Archives of Internal Medicine, 2002
- Reduction of variation in T‐cell subset enumeration among 55 laboratories using single‐platform, three or four‐color flow cytometry based on CD45 and SSC‐based gating of lymphocytesCytometry, 2002
- Evaluation of TruCount Absolute-Count Tubes for Determining CD4 and CD8 Cell Numbers in Human Immunodeficiency Virus-Positive AdultsClinical and Diagnostic Laboratory Immunology, 2000
- Guideline for flow cytometric immunophenotyping: A report from the national institute of allergy and infectious diseases, division of AIDSCytometry, 1993
- Evaluation of a dual‐color flow cytometry immunophenotyping panel in a multicenter quality assurance programCytometry, 1993
- Basic phenotyping of lymphocytes: Selection and testing of reagents and interpretation of dataClinical Immunology Newsletter, 1990