Incomplete Adherence Linked to Greater Risk for Residual Low-Level Viremia

Keith Henry, MD

Use of a single-copy HIV RNA assay among patients on ART with HIV RNA levels <50 copies/mL showed that missing doses increased risk for low-level viremia.

With many currently recommended antiretroviral therapy (ART) regimens, complete adherence is not always needed to maintain HIV RNA levels <50 copies/mL. However, incomplete adherence may result in higher levels of residual viremia (1–49 copies/mL) that could replenish the viral reservoir, lead to viral rebound, or both.

In a recent, partially industry-funded study involving homeless or marginally housed HIV-infected adults in San Francisco, researchers used a single-copy assay to explore this issue. Eligibility requirements included treatment with combination ART (≥3 drugs) and viral load <50 copies/mL for ≥6 months. Adherence was assessed by unannounced pill counts. Sixty-four patients were included in the analysis (median age, 46; 81% male; median CD4 count, 477 cells/mm3; median duration of viral suppression, 10.5 months; median ART adherence during the preceding 1 and 2 months, 94% and 93%, respectively).

Residual viremia was detected in 47% of the participants (including 4 of 12 with 100% adherence during the preceding 2 months). On multivariate analysis, ART adherence over the preceding 2 months — but not duration of viral suppression, CD4-cell count, or ART regimen — was associated with residual viremia. Similarly, on multivariate analysis, only ART adherence was associated with risk for virologic failure (i.e., HIV RNA >50 copies/mL).

CITATION(S):

Li JZ et al. Incomplete adherence to antiretroviral therapy is associated with higher levels of residual HIV-1 viremia. AIDS 2014 Jan 14; 28:181. (http://dx.doi.org/10.1097/QAD.0000000000000123)