Suboptimal Adherence to Combination Antiretroviral Therapy Is Associated with Higher Levels of Inflammation despite HIV Suppression

Abstract

Background. Human immunodeficiency virus (HIV)–infected individuals exhibit residual inflammation regardless of virologic suppression. We evaluated whether suboptimal adherence to combination antiretroviral therapy (cART) is associated with greater residual inflammation than optimal adherence, despite virologic suppression. Methods. Longitudinal self-reported cART adherence data and serum concentrations of 24 biomarkers of inflammation and immune activation were measured at the same study visit in HIV RNA–suppressed (<50 copies/mL) HIV-infected men in the Multicenter AIDS Cohort Study from 1998 to 2009. Associations between dichotomized 6-month (<100% vs 100%) and categorized 4-day (<85%, 85%–99%, and 100%) cART adherence with biomarker concentrations were evaluated. Results. A total of 912 men provided 2816 person-visits with documented plasma HIV RNA suppression. In adjusted models, person-visits at which <100% cART 6-month adherence was reported had higher concentrations of interleukin 2, 6, and 10, interferon γ, tumor necrosis factor α, and C-reactive protein than person-visits at which 100% cART adherence (P < .05) was reported. These same differences were observed in person-visits reporting <85% versus 100% 4-day cART adherence, but not in visits reporting 85%–99% versus 100% cART adherence. After adjustment for multiple comparisons, tumor necrosis factor α remained significantly higher (11% increase; P < .001) in person-visits at which <100% adherence was reported. Conclusions. Higher concentrations of inflammatory biomarkers were observed among HIV RNA–suppressed men who reported <100% cART adherence than among more adherent men. Residual HIV replication (ie, below the limit of detection), more likely among men with suboptimal adherence, is a plausible mechanism. Whether improving cART adherence could affect residual inflammation and associated morbidity and mortality rates should be investigated.