       Document 0587
 DOCN  M9610587
 TI    Quantification of the variation due to laboratory and physiologic
       sources in CD4 lymphocyte counts of clinically stable HIV-infected
       individuals.
 DT    9601
 AU    Raboud JM; Haley L; Montaner JS; Murphy C; Januszewska M; Schechter MT;
       Department of Health Care and Epidemiology, Faculty of Medicine,; St.
       Paul's Hospital, University of British Columbia, Vancouver,; Canada.
 SO    J Acquir Immune Defic Syndr Hum Retrovirol. 1995;10 Suppl 2:S67-73.
       Unique Identifier : AIDSLINE MED/96033815
 AB    We have conducted a study to quantify the amount of variation in the CD4
       lymphocyte counts of HIV-infected individuals due to laboratory and
       physiological factors. Thirty HIV-infected male volunteers had blood
       drawn on six occasions: three times in each of 2 weeks, 4 weeks apart.
       Two tubes of blood were drawn at each visit, and duplicate measurements
       were obtained from one of the tubes of blood. Differences between
       duplicate measurements from a single tube of blood and between CD4
       counts obtained from two tubes of blood drawn on the same day were
       attributed to laboratory factors. Differences between CD4 counts
       obtained on different days were attributed to a combination of
       laboratory factors and physiologic factors, which included the effects
       of exercise, tobacco, and the consumption of alcohol and caffeine. The
       mean absolute CD4 count at the first visit was 450 (range 86-1,081). The
       short-term coefficient of variation of CD4 count was 13.7 (95% CI: 12.9,
       14.6). Physiologic and laboratory factors accounted for 85% and 15% of
       the variation in CD4 counts, respectively. Variation in the absolute
       white blood cell count, lymphocyte percentage, and CD4 percentage
       accounted fo 52%, 29%, and 19% of the physiologic variation in CD4
       counts, respectively. Our results confirm a high degree of short-term
       variability of CD4 counts among HIV-infected individuals, which can be
       largely attributed to physiological factors. This variability can be
       minimized more effectively by repeating CD4 counts over time than by
       repeating measurements at a single visit.(ABSTRACT TRUNCATED AT 250
       WORDS)
 DE    Adult  Alcohol Drinking/BLOOD  Antiviral Agents/THERAPEUTIC USE
       Biological Markers  Caffeine/PHARMACOLOGY  *CD4 Lymphocyte Count
       Exercise/PHYSIOLOGY  Human  HIV Infections/DRUG THERAPY/*IMMUNOLOGY
       Male  Middle Age  Reproducibility of Results  Smoking/BLOOD  Support,
       Non-U.S. Gov't  JOURNAL ARTICLE

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

