Association of CD8 + T Lymphocyte Subsets with the Most Commonly Used Markers to Monitor HIV Type 1 Infection in Children Treated with Highly Active Antiretroviral Therapy

Abstract

In contrast to adults, there is no information about children concerning the effects of the new antiretroviral therapy on the chronic activation and expansion of CD8⁺ T cells. We have investigated the relationship between blood CD8⁺ T cell subsets, with percent CD4⁺ cells (%CD4), percent CD8⁺ cells (%CD8), and plasma viral load (VL), in 39 vertically HIV-1-infected children receiving highly active antiretroviral therapy (HAART) (mean age, 7.6 years; range, 2-15.6 years). CD8⁺ subsets were examined by three-color multiparametric flow cytometry, and VL was quantified by standard assays. There was a strong positive correlation between activated CD8⁺ T cells and VL. An increase in memory and memory-activated CD8⁺ T cells correlated with increased VL, whereas nonactivated memory cells and CD28⁺CD8⁺ T cells correlated negatively with VL. Naive and effector cells did not correlate with VL, although the CD8⁺CD45RA^-CD62L^- subset correlated with increased VL. Activated CD8⁺ T cells did not correlate with %CD4, but an increase in memory-activated and effector CD8⁺ T cells was associated with lower %CD4. Increased naive CD8⁺ and CD28⁺CD8⁺ T cells showed a positive correlation with %CD4 and a negative correlation with %CD8. In conclusion, in HIV-1-infected children receiving HAART, the activation of CD8⁺ T cells is associated with high VL, whereas CD8⁺CD28⁺ and nonactivated CD8⁺ memory cells are associated with lower viral load. Naive CD8⁺ and CD28⁺CD8⁺ T cells are associated with an improved immunological status.