CD95 (APO-1/Fas) expression on naive CD4(+) T cells increases with diseaseprogression in HIV-infected children and adolescents: Effect of highly active antiretroviral therapy (HAART)

We studied the expression of the CD95 receptor (APO-1/Fas) on peripheral bl ood T cell subpopulations in 37 HIV-l-infected children and adolescents str atified according to disease stage or antiretroviral treatment regimen and compared the results to values obtained in 12 healthy age-matched control s ubjects. CD95 expression on CD45RA(+) CD45RO(-)/CD62L(+) (resting/ naive) a nd CD45RO(+) CD45RA(-) (primed/memory) CD4(+) and CD8(+) T cells was assess ed quantitatively by four-color and three-color flow cytometry. CD4(+) T ce lls contained a population of predominantly CD95(-) resting/naive cells and a population of CD95(high) primed/memory cells, whereas CD8(+) T cells had a more uniform pattern of CD95 expression. The percentage of CD95(+) CD4() T cells increased with disease progression because of both an augmented m edian fluorescence intensity on resting/naive cells and an increased percen tage of CD95(high) cells. Patients with highly active antiretroviral combin ation therapy who maintained stable CD4 counts in the presence of elevated plasma viral load had nearly normal numbers of CD95 resting/ naive CD4(+) T cells, whereas CD95 expression in the CD8(+) T cell subset was still eleva ted compared with control subjects. Low CD95 expression on resting/naive CD 4(+) T cells may therefore indicate a tow risk for disease progression in a ntiretrovirally treated and untreated patients.