Characterizing the immune system after long-term undetectable viral load in HIV-1-infected children

Thirty two HIV-infected children, on highly active antiretroviral therapy (HAART) and > 500 CD4(+) T cells/mm(3), were rated according to the time-course of viral load (VL) during the whole follow-up period (> 18 months) in a longitudinal retrospective study. ( a) uVL group: 15 children with VL below 400 copies/mL; ( b) dVL group: 17 children with higher VL. The uVL group showed higher memory ( CD4(+)CD45RO(+)) T cells than did dVL group, and higher number of memory activated CD4(+)CD45RO(+)HLA-DR+ than did control group ( healthy age-matched uninfected children), whereas CD4(+)CD45RA(hi+)CD62L(+) was similar. However, TCR rearrangement excision circles ( TRECs) were higher in uVL group than in dVL group. uVL Group showed CD8(+)CD45RO(+) and CD8(+)CD45RO(+)CD38(+) higher number than the control group, but lower than the dVL group. The percentage of CD8(+)CD45RA(hi+)CD62L(+), CD8(+)CD45RA(+), CD8(+)CD62L(+), and CD8(+)CD28(+) was higher in uVL group than in dVL group, and lower than in control group. The uVL group showed higher number of activated (HLA-DR(+)CD38(+), HLA-DR+, HLA-DR(+)CD38(-)) CD4(+) T cells and lower percentages of CD4(+)HLA-DR(-)CD38(+) than dVL group. In activated CD8(+) T cell, the uVL group had lower CD8(+)HLA-DR(+)CD38(+), CD8(+)HLA-DR+, and CD8(+)CD38(+) than the dVL group. Preeffector (CD8(+)CD57(-)CD28(-) and CD8(+)CD45RA(-)CD62L(-)) T cells were lower in the uVL group than in dVL group. In the effector ( CD8(+)CD57(+), CD8(+)CD57(+)CD28(-), and CD8(+)CD45RA(+)CD62L(-)) T cells, HIV-infected-children had higher values than control group. HIV-infected-children who respond to HAART had TRECs reconstitution, decreased immune activation, and lower effector CD8(+) T cells. Moreover, successful HAART allow the increment of activated CD4(+) T cells.