Publications

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.

The CCR5 inhibitor maraviroc has been hypothesized to decrease T-cell activation in HIV-infected individuals, but its independent immunologic effects have not been established in a placebo-controlled trial. We randomized 45 HIV-infected subjects with CD4 counts <350 cells per mm(3) and plasma HIV RNA levels <48 copies per mL on antiretroviral therapy (ART) to add maraviroc vs placebo to their regimen for 24 weeks followed by 12 weeks on ART alone. Compared with placebo-treated subjects, maraviroc-treated subjects unexpectedly experienced a greater median increase in % CD38+HLA-DR+ peripheral blood CD8+ T cells at week 24 (+2.2% vs -0.7%, P = .014), and less of a decline in activated CD4+ T cells (P < .001). The % CD38+HLA-DR+ CD4+ and CD8+ T cells increased nearly twofold in rectal tissue (both P < .001), and plasma CC chemokine receptor type 5 (CCR5) ligand (macrophage-inflammatory protein 1β) levels increased 2.4-fold during maraviroc intensification (P < .001). During maraviroc intensification, plasma lipopolysaccharide declined, whereas sCD14 levels and neutrophils tended to increase in blood and rectal tissue. Although the mechanisms explaining these findings remain unclear, CCR5 ligand-mediated activation of T cells, macrophages, and neutrophils via alternative chemokine receptors should be explored. These results may have relevance for trials of maraviroc for HIV preexposure prophylaxis and graft-versus-host disease. This trial was registered at www.clinicaltrials.gov as #NCT00735072.

BACKGROUND

While persistent T-cell activation has been cross-sectionally associated with poor CD4+ T-cell restoration in HIV-infected individuals maintaining antiretroviral treatment (ART)-mediated viral suppression, it remains unclear whether CD8+ T-cell activation is of predictive effect on CD4+ T-cell recovery.

OBJECTIVE

We assessed whether the extent of persistent CD8+ T-cell activation (% CD38+/HLA-DR+) in the first few years of ART-mediated viral suppression predicted subsequent CD4+ T-cell recovery in 95 subjects with up to 15 years of observation on suppressive ART.

RESULTS

Lower CD8+ T-cell activation and higher naïve CD4+ T-cell frequencies (CD45RA+/CD62L+) measured at year 3 to 5 after starting ART independently predicted greater subsequent CD4+ T-cell increases. The mean CD4 count increase from year 0 to year 5 and the increase to the average of year 10 to 15 in the low CD8 activation group (≤18.5%; mean = 13%) were 342 and 458 cells/mm,3 and the increases were 248 and 349 cells/mm3 for the high CD8 activation group (≯18.5%; mean = 29%) (P = .002 and P = .016, respectively, comparing groups). At years 10 to 15, the mean CD4 counts in the groups were 579 and 484 cells/mm3, respectively (P = .026).

CONCLUSION

These findings support the need to identify approaches to reduce immune activation in treated HIV disease.

We examined the association between CD4 cell count and adherence in a cohort of Ugandans initiating antiretrovirals (ARVs). Outcomes were (a) adherence <90%; (b) any treatment interruptions > 72 hours; (c) number of treatment interruptions; and (d) HIV-RNA >400 copies/mL. We fit regression models to estimate associations with our exposure of interest, baseline CD4 cell count ≥ 250 cells/μL (n = 60) vs <250 cells/μL (n = 413). CD4 cell count ≥250 cells/μL was independently associated with increased odds and number of treatment interruptions and increased odds of persistent viremia. Interventions to support adherence in patients with higher CD4 cell counts should be considered as drug availability to this population increases.