Soluble biomarkers of immune activation and inflammation in HIV infection: impact of 2 years of effective first‐line combination antiretroviral therapy

Objectives The aim of the study was to assess the impact of rapid and sustained viral control produced by combination antiretroviral therapy (cART) on HIV-associated immune activation and inflammation. Methods In this longitudinal observational study, we examined changes in interleukin-6 (IL-6), interferon-γ-inducible protein-10 (IP-10), monokine induced by interferon-γ (MIG) and soluble CD14 (sCD14) levels during 2 years of effective first-line cART. Biomarker levels before and after cART were compared with those observed in healthy subjects, using the Wilcoxon signed rank test. Elevated biomarker levels were defined with respect to values for healthy subject (mean + 2 standard deviations). Factors associated with persistently elevated biomarker levels after 2 years of cART were identified by logistic regression. Results We included in the study 139 patients with a median HIV-1 RNA level of 4.8 log10 HIV-1 RNA copies/mL and a median CD4 cell count of 294 cells/μL at cART initiation [day 0 (D0)]. At D0, all biomarker levels were higher than in healthy subjects (P   75% of patients. In contrast, sCD14 levels did not change significantly (0.18 × 106 pg/mL; P = 0.102) and remained elevated. Older age was associated with elevated levels of IP-10 [odds ratio (OR) 1.60 per 10 years older; P = 0.047] and MIG (OR 1.92 per 10 years older; P = 0.007) after 2 years of cART. Conclusions The rapid and sustained viral suppression produced by first-line cART reduced IL-6, IP-10 and MIG to normal levels, while sCD14, a marker of monocyte activation, remained elevated. High levels of IP-10 and MIG tended to persist in older patients.