       Document 0760
 DOCN  M9640760
 TI    Evaluation of four alternative methodologies for determination of
       absolute CD4+ lymphocyte counts. The National Heart, Lung, and Blood
       Institute Retrovirus Epidemiology Donor Study.
 DT    9604
 AU    Johnson D; Hirschkorn D; Busch MP; Irwin Memorial Blood Centers, San
       Francisco, CA 94118, USA.
 SO    J Acquir Immune Defic Syndr Hum Retrovirol. 1995 Dec 15;10(5):522-30.
       Unique Identifier : AIDSLINE MED/96142214
 AB    Standard methods for determining absolute CD3+CD4+ T-lymphocyte
       concentrations using combined results from flow cytometry and hematology
       analyzers are expensive and require fresh (< 18 h old) blood. We
       evaluated four new alternative methods for determining absolute CD4+
       T-lymphocyte counts; (a) the FACSCount System (Becton Dickinson
       Immunocytometry Systems), (b) VCS Technology/Coulter Cyto-Spheres
       (Coulter Corporation), (c) Zymmune CD4/CD8 Cell Monitoring Kit (Zynaxis,
       Inc.), and (d) TRAx CD4 Test Kit (T Cell Diagnostics).
       EDTA-anticoagulated whole-blood specimens from HIV-seropositive patients
       and anti-HIV-negative adult blood donors and staff were tested by the
       standard flow cytometry method on fresh blood (0-6 postphlebotomy) and
       by the four alternative methods at 0 to 6 h and 24 to 30 h
       postphlebotomy. Representative specimens (< 6 h old) were tested five
       times with each system to evaluate reproducibility. Correlation
       coefficients for absolute CD4+ counts between standard flow cytometry
       and the alternative methods ranged from 0.84 to 0.92 for both fresh and
       24- to 30-h-old specimens. Average coefficient of variation for
       reproducibility ranged from 4.5 to 7.1%. The four alternative CD4+
       T-lymphocyte counting methods performed well relative to standard
       methods. Each alternative method offers advantages over standard flow
       cytometry with respect to sample throughout, required technical
       expertise, and cost per result. These methods should facilitate wider
       availability of low-cost CD4 counts.
 DE    Blood Donors  Comparative Study  CD4 Lymphocyte Count/*METHODS  CD4-CD8
       Ratio  CD4-Positive T-Lymphocytes/*IMMUNOLOGY  Evaluation Studies  Flow
       Cytometry  Human  HIV Seropositivity/*IMMUNOLOGY  Reproducibility of
       Results  Support, U.S. Gov't, P.H.S.  JOURNAL ARTICLE

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

