       Document 0999
 DOCN  M9650999
 TI    Potential clinical implications of interlaboratory variability in CD4+
       T-lymphocyte counts of patients infected with human immunodeficiency
       virus.
 DT    9505
 AU    Sax PE; Boswell SL; White-Guthro M; Hirsch MS; Infectious Disease
       Division, Brigham and Women's Hospital,; Boston, Massachusetts 02115,
       USA.
 SO    Clin Infect Dis. 1995 Nov;21(5):1121-5. Unique Identifier : AIDSLINE
       MED/96125992
 AB    The CD4+ T-lymphocyte count is an important factor in the management of
       patients infected with human immunodeficiency virus. Previous studies
       have found significant variability among the counts determined by
       different laboratories. We conducted a study of lymphocyte phenotyping
       in four laboratories to assess this variability and its possible
       clinical implications. One laboratory was situated at the study site;
       the other three were selected randomly from a total of 11 commercial and
       hospital laboratories available locally. Blood specimens were obtained
       from 24 patients and were sent to the four laboratories for a complete
       blood count and a lymphocyte subset analysis. Using the Kruskall-Wallis
       test, we found that the laboratories' ranks of four individual
       components of the CD4 cell count differed significantly: total white
       blood cell count (P < .0001), lymphocyte percentage (P = .003),
       lymphocyte count (P = .002), and CD4 percentage (P = .0004). Of the 24
       patients in this survey, 14 (58.3%) had CD4-count results with enough
       variation to have led to conflicting treatment recommendations; three of
       the 24 patients fulfilled the revised Centers for Disease Control and
       Prevention case definition of AIDS on the basis of results from some but
       not all laboratories. In addition, the laboratories disagreed on whether
       CD4 cell counts of nine patients (37.5%) had increased or decreased
       since the previous determination. We conclude that when strict
       thresholds of CD4 cell counts are used as a basis for treatment
       recommendations or for diagnosis of AIDS, interlaboratory variability
       may be sufficient to alter the decisions made.
 DE    Acquired Immunodeficiency Syndrome/DIAGNOSIS/IMMUNOLOGY  Analysis of
       Variance  *CD4 Lymphocyte Count  Female  Human  HIV
       Infections/CLASSIFICATION/*IMMUNOLOGY/THERAPY  Laboratories  Male
       Support, Non-U.S. Gov't  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).

