IMMUNOPHENOTYPING OF T-LYMPHOCYTES BY 3-COLOR FLOW-CYTOMETRY IN HEALTHY NEWBORNS, CHILDREN, AND ADULTS

Reagents are now available which allow simultaneous assessment of thre e different fluorescence wavelengths on most commercially available fl ow cytometers. Such three-color analyses provide more information than single- or dual-color analyses. The present study was undertaken in o rder to establish age-related differences in lymphocyte subpopulations by simultaneously measuring three surface antigens in newborns, child ren, and adults. A whole blood method was used to label cells with ant ibodies conjugated to FITC, PE, and perCP. We found that the percentag e of lymphocytes expressing HLA-DR/CD28/CD8, HLA-DR/ CD38/CD8, CD95/CD 45RO/CD8, CD95/CD45RO/CD4, CD95/CD4, and CD95/CD8 showed relative incr eases with age. The percentage of lymphocytes expressing CD28/CD8, CD3 8/CD8, and CD38/CD4 showed relative decreases with age, while the subs et HLA-DR/CD38/ CD4 did not change, Three-color how cytometry is a pow erful tool to more precisely define lymphocyte subsets than the curren t two-color methods. We present values using a three-color panel in he althy newborns, children, and adults. (C) 1997 Academic Press.