Flow cytometric determination of quantitative immunophenotypes

Abstract

Immunofluorescent flow cytometric analysis of peripheral blood leucocytes is most commonly used to identify and enumerate cells defined by one or more clusters of differentiation (CD) antigens. Although less widely employed, quantitative tests that measure the amounts of CD antigens expressed per cell are used in some situations such as the characterization of lymphomas and leukocytes or the measurement of CD38 on CD3plu8pluT cells in HIV infected individuals. The CD antigens used to identify leukocyte populations are functionally important molecules and it is known that under- or over-expression of some CD antigens can affect cellular responses. For example, high or low expression of CD19 on B cells is associated with autoimmune conditions or depressed antibody responses, respectively. In the current studies, the quantitative expression of CD antigens on T cells, B cells and monocytes was determined in a group of age and sex-matched Marines at several times before and after training exercises. There was substantial variation among these individuals in the quantitative expression of CD antigens and in the number of cells in various populations. However, there was relatively little variation within individuals during the two months they were examined. Thus, the number of cells in leukocyte sub-populations and the amount of CD antigens expressed per cell appear to comprise a characteristic quantitative immunophenotype.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.