Brodie AR, Brown AS, McClure HM; Symposium on Nonhuman Primate Models for AIDS.
J Med Primatol. 1992 Sep-Oct; 21: abstract no. 96.
Yerkes Primate Research Center, Emory University, Atlanta, GA.
A critical determination in AIDS patients and in nonhuman primate AIDS animal models is the determination of CD4+ lymphocytes. This value is used to monitor disease progression and response to therapy, and should be reported in absolute numbers. The latter depends on determining the percent of lymphocytes in a differential count, and these determinations are known to vary up to 27% when manual differentials are done. Unless each laboratory establishes a strict quality control program, the results of immunophenotyping, based on total leukocyte counts and differential counts, can be seriously compromised. In our laboratory, the complete blood count done on each specimen for immunophenotyping by flow cytometry includes a 100 cell manual differential done on Wright Giemsa stained slides. The percent of lymphocytes derived from this differential is used to calculate the absolute number of T & B cells (CD2 and CD20), T helper and T suppressor cells (CD4 and CD8), NK cells (CD56), and IL2 receptor cells (CD25). The absolute numbers of these various lymphocyte subsets are used to monitor disease progression in SIV infected animals and to monitor their response to drug treatment. A technique has been established to verify the % lymphocytes obtained from the manual differential. The WBC histogram printout from a Sysmex F800 or Sysmex K1000 and the number of manually gated lymphocytes from the Simulset Software program are compared to the manual differential result. These comparisons have been made on 400 differentials to date; 54% were within +/- 5% and an additional 33% were within +/- 10% when all 3 counts were compared. Any values that varied more than 10% were rechecked by repeating the manual differential and/or repeating the automated CBC. This three way comparison provides an internal quality control that helps to insure valid absolute counts for CD4+ cells, as well as other lymphocyte subsets.
Publication Types:
Keywords:
- Acquired Immunodeficiency Syndrome
- Antigens, CD4
- Antigens, CD56
- Antigens, CD8
- CD4-Positive T-Lymphocytes
- Disease Progression
- Flow Cytometry
- Humans
- Immunophenotyping
- Leukocyte Count
- Leukocytes
- Lymphocyte Count
- Lymphocyte Subsets
- Lymphocytes
- Models, Animal
- Quality Control
- Receptors, Interleukin-2
- Simian Acquired Immunodeficiency Syndrome
- T-Lymphocytes, Regulatory
- immunology
- therapy
Other ID:
UI: 102202436
From Meeting Abstracts