BACKGROUND: Human immune defect virus (HIV) persists in a latent state in quiescent CD4+ T cells preventing eradication of HIV. CD52 is a surface molecule modulated by HIV. We aimed at examining factors related to CD52 expression on CD4+ T cells in HIV-positive individuals and the impact of initiation of combination antiretroviral therapy (cART).

METHODS: Peripheral blood mononuclear cells (PBMC) from 18 HIV-positive individuals and 10 uninfected age and gender matched controls were examined by flow cytometry for CD38 and CD52 expression on CD4+ T cells. Stimulation assays were performed on 8 healthy blood donors to determine a cut-off for CD52 expression.

RESULTS: All examined CD4+ T cells expressed CD52. However, both CD4+ T cells with higher (CD52++) and with lower CD52 expression (CD52dim) were found in HIV-positive individuals compared to uninfected controls. Two % CD52dim cells defined groups of high and low CD52: The group of individuals with high CD52 had higher CD4 counts at baseline (447 vs. 54 cells/µL, p=0.02) and higher increase of CD4 counts during follow-up compared to low CD52 (p=0.02). After 12 months of cART CD52 increased (MFI 4846 vs.5621, p<0.05), while CD38 decreased (MFI 1519 vs. 730, p<0.0001).

CONCLUSIONS: All HIV-positive individuals in this cohort had CD4+ T cells that expressed CD52. Higher CD4 counts were found in those with high CD52. Furthermore, an increase in CD52 was found after 12 months of cART, indicating that anti-CD52 antibodies may be more efficient for depletion of CD4+ T cells in HIV-positive individuals on cART.