Systemic inflammation and residual viraemia in HIV-positive adults on protease inhibitor monotherapy: a cross-sectional study

Alejandro Arenas-Pinto, Ana Milinkovic, Dimitra Peppa, Anna McKendry, Mala Maini, Richard Gilson

Increased levels of markers of systemic inflammation have been associated with serious non-AIDS events even in patients on fully suppressive antiretroviral therapy. We explored residual viremia and systemic inflammation markers in patients effectively treated with ritonavir-boosted protease inhibitor monotherapy (PImono). HIV-infected adults with persistent HIV-RNA <50 copies/ml and treated with either a) PImono or b) standard triple-drug cART were recruited for this cross-sectional, exploratory study. Plasma samples were tested for high-sensitivity CRP (hsCRP), Serum Amyloid A (SAA), soluble CD14, IL-6, IL-8 and Cytochrome C. HIV-RNA was measured by real-time PCR (detection limit of 10 copies/ml). 81 patients were recruited (31% on PImono). Two out of 25 (8%) and 3 of 56 (5.4%) patients from the PImono and cART groups respectively had detectable HIV-RNA. Significant correlation between SAA and hsCRP was observed (0.804). No difference between groups was found on prevalence of hsCRP >3 mg/l (21% vs 20% in the PImono and cART groups respectively; p = 0.577) or SAA >6.4 mg/l (38% vs 22% in the PImono and cART groups respectively; P = 0.172). In a univariate analysis IL6 and IL8 levels were associated with SAA >6.4 mg/l (OR = 1.74 and 1.46; 95% CI = 1.00 - 3.03 and 1.06 - 2.01; p = 0.051 and 0.02 respectively) and hsCRP >3 mg/l in (OR = 2.00 and 1.37; 95% CI = 1.09 - 3.69 and 1.02 - 1.85; p = 0.026 and 0.039 respectively). We found no evidence of increased levels of inflammatory biomarkers or higher prevalence of residual viraemia in patients effectively suppressed on PImono as compared with patients on standard cART.