The expression of CD38 on CD8+ T-lymphocyte is a significant predictive value in disease progression of HIV infected individuals and in monitoring a response to therapy. CD38 molecules expressing on CD3+ and CD8+ T-cells were measured quantitatively by flow cytometry in 30 healthy Thai adults. In each experiment, the known amount of fluorochrome in CD38 antibodies bound per cell of QuantiBRITE PE beads was plotted, and set a regression line. With this line, the amount of CD38 molecules bound to CD3 and CD8 target cells was estimated. The aim of this study was to determine the reference value of CD38 molecules on CD8+ T-lymphocyte, which is the baseline in comparison to the CD38 molecule expressing on CD8+ T-lymphocyte in HIV-infected individuals. The present results showed that the amount of CD38 expressions on CD8+ T-lymphocyte in HIV negative Thai adults was about 2 times higher than those from Caucasianís lymphocyte. The reference range of CD38 molecules in the present study would best be used as baseline in prognosis and drug monitoring of HIV-1 infection in Thailand.

Keywords: CD38, T-lymphocyte, HIV-1 infection, Thai adults, Reference value, Prognosis, Flow cytometry