       Document 0828
 DOCN  M9620828
 TI    Interlaboratory variability of CD8 subset measurements by flow cytometry
       and its applications to multicenter clinical trials. NAID/NICHD Women
       and Infants Transmission Study Group.
 DT    9602
 AU    Landay AL; Brambilla D; Pitt J; Hillyer G; Golenbock D; Moye J;
       Landesman S; Kagan J; Rush-Presbyterian-St. Luke's Medical Center,
       Chicago, Illinois; 60612, USA.
 SO    Clin Diagn Lab Immunol. 1995 Jul;2(4):462-8. Unique Identifier :
       AIDSLINE MED/96082425
 AB    Recent studies have demonstrated the utility of measuring subsets of
       CD8+ T cells as prognostic markers in epidemiology cohort studies of
       human immunodeficiency virus (HIV)-infected patients. Most of these
       studies evaluating the value of CD8+ T-cell subsets have been performed
       at single centers, and few data are available on variability in the
       measurement of the CD8+ cell populations in multicenter trials. In the
       current study, we addressed this question by evaluating interlaboratory
       variability from the five laboratories enrolled in the Women and Infants
       Transmission Study sponsored by the National Institutes of Health. This
       study evaluated 35 HIV-positive and 28 HIV-negative proficiency testing
       samples sent to the laboratories for evaluation. The study focused on
       the robust coefficient of variation (RCV) for CD38 (11%), HLA-DR (21%),
       and CD57 (15%) expression on the CD8+ population. Data from the current
       study indicated that the variability in these measurements is greater
       than that for CD3+ CD4+ (RCV, 5%) and CD3+ CD8+ (RCV, 5%) cells.
       Knowledge of the variability of the CD8+ subset measurements should
       guide investigators in the design and analysis of clinical trials and
       epidemiology studies. Ability to obtain improved interlaboratory
       agreement on CD8+ subset measurements will facilitate further evaluation
       of these markers in HIV studies.
 DE    Antigens, CD3/ANALYSIS  Antigens, CD8/ANALYSIS  CD8-Positive
       T-Lymphocytes/*CHEMISTRY  Diagnosis, Laboratory/STATISTICS & NUMER
       DATA/*STANDARDS  Flow Cytometry/STATISTICS & NUMER DATA/*STANDARDS
       Human  HIV Seronegativity  HIV Seropositivity/DIAGNOSIS
       Immunophenotyping/STANDARDS  Lymphocyte Count  Multicenter
       Studies/STANDARDS  Reproducibility of Results  Support, U.S. Gov't,
       P.H.S.  CLINICAL TRIAL  JOURNAL ARTICLE  MULTICENTER STUDY

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

