Objective: To explore the characteristics of immunophenotypic alterations of HIV-infected persons/AIDS patients--people living with AIDS (PLWA).
Methods: The clinical data and anti-coagulated blood samples of 263 treatment naive PLWA and 56 healthy controls were collected. Flow cytometry was used to determine the sets of peripheral lymphocytes: B cell, NK cell, CD4(+) T cell including the functional subset (CD28(+)CD4(+) cell), naïve subset (CD4(+)CD45RA(+)CD62L(+) cell), and memory subset (CD4(+)CD45RA(-)cell) of CD4(+) T cell, CD8(+) T cell including the activated subset (CD8(+)CD38(+) cell). Branch DNA (bDNA) assay was used to detect the plasma viral load.
Results: The mean CD4(+) T cell count, naïve CD4(+) T cell percentage, and CD28 expression rate in CD4(+) T cells of the PLWA were 205 (348, 63) x 10(6) cells/L, 18.5 (32.0, 6.5)%, and 86.1 (94.0, 68.3)% respectively, all significantly lower than those of the healthy controls [787 (1058, 615) x 10(6) cells/L, 35.4 (45.5, 30.0)%, and 95.7 (97.6, 91.0)% respectively, all P < 0.01]. The percentage of CD38 expression in CD8(+) T cells of the PLWA was 84.3 (92.7, 69.0)%, significantly higher than that of the controls [42.6 (50.6, 36.1)%, P < 0.01]. In the PLWA the CD4(+) T cell count was positively correlated with its CD28 expression (r = 0.480, P < 0.01), and the percentage of CD38 expression in CD8(+) T cells was positively correlated with eh plasma viral load (r = 0.331, P < 0.01). The PLWA were divided into 3 groups according to the CD4(+) T cell count: Group A with the he CD4(+) T cell count < 200 x 10(6) cells/L, Group B with the CD4(+) T cell count of 200 - 350 x 10(6) cells/L, and Group C with the CD4(+) T cell count > 350 x 10(6) cells/L. In comparison with Groups B and C the plasma viral load, activated CD8(+) T cell subset proportion, and percentage of memory CD4(+) T cells of Group A were all significantly higher, and the naive CD4(+) T cell percentage and CD28 expression rate were both significantly lower (all P < 0.01). There were no significant differences in the percentage of memory CD4(+) T cells, CD28 expression, and CD8(+) T cell activated subset proportion between Groups B and C.
Conclusion: The major immunophenotypic alternations in the PLWA in China include significantly lower counts of CD4(+) T cells and their naive subsets, marked down-regulation of CD28 expression and extremely activated CD8(+) T cells. Distinct features of the immunophenotypic alteration may exist in different disease stages. The CD4(+) T cell count < 200 x 10(6) cells/L may predict more severe immunodeficiency.