CD8+ T-cell activation in HIV-1-infected patients experiencing transient low-level viremia during antiretroviral therapy.

Transient low-level viremia (TLLV) of 50-400 HIV RNA copies per milliliter is common during antiretroviral therapy, but its pathogenesis, consequences, and optimal management are unclear. Heightened immune activation is associated with detrimental outcomes, including impaired CD4 T-cell reconstitution. Using CD38/HLA-DR expression on CD8 T cells measured in 2 large studies, we determined associations between TLLV and immune activation levels before, during, and after TLLV. We found that TLLV does not significantly change CD8 T-cell activation and that higher CD8 T-cell activation during viral suppression <50 copies per milliliter is associated with a modest increase in the risk of a subsequent TLLV.