TIMING OF LYMPHOCYTE-ACTIVATION IN NEONATES INFECTED WITH HUMAN-IMMUNODEFICIENCY-VIRUS

Human immunodeficiency virus (HIV) infection in children is associated with qualitative and quantitative changes in the peripheral lymphocyt e surface phenotype beyond the normal maturational changes, Neonates, however, have been reported to have a delayed immune response to HIV c ompared to HIV-infected adults, We prospectively performed immunopheno typing of T lymphocytes by three-color immunofluorescent labeling and laser flow cytometry to determine the timing of phenotypic alterations in 112 neonates born to HIV-infected mothers, Serial testing was perf ormed at birth (cord blood) and at 2, 6, and 12 weeks of age, Data wer e divided retrospectively for analysis into those for HIV-infected (n = 14) infants and those for exposed, uninfected infants, Our results s how that both infected and uninfected infants had a decline in the per centages and numbers of CD4 cells beginning at 2 weeks of age but that the decline was greater in the HIV-infected group, The activation and differentiation of CD8 T cells in HIV+ infants were shown by a signif icant increase in CD45RA(-)CD45RO(+)CD8(+) cells by 6 weeks of age and by increases in CD8(+)S6F1(+)CD3(+) cells and HLA-DR(+)CD38(+)CD8(+) cells by 2 weeks of age. These results indicate that HIV-infectcd neon ates show alterations in T-cell phenotype reflecting those reported fo r older HIV-infected children, Most importantly, neonatal T cells are able to respond to RIS' within the first weeks of life.