The FIB-4 Is a Marker of Monocyte/Macrophage Activation Independently from Severe Hepatic Disease in People Living with HIV on Stable and Successful Treatment

Objectives: Despite successful antiretroviral treatment (ART), people living with HIV (PWH) continue experiencing chronic immune activation and comorbidities. We analysed whether the Fibrosis 4 index (FIB-4) is associated with monocyte–macrophage activation in PWH with non-severe hepatic disease. Materials and Methods: We performed a cross-sectional analysis about factors associated with monocyte–macrophage activation among PWH either on triple or dual ART. Background measurements, comorbid conditions and FIB-4 values were correlated with plasmatic markers of monocyte–macrophage activation (sCD163 and sCD14) using univariate and linear regression analysis. Results: We included 366 subjects (age 60.5, 75% male, years of HIV infection 24.5, mean FIB-4 1.52, 8% with FIB-4 > 2.67, Body Mass Index 24.5). In univariate analysis, FIB-4 was associated with older age, years of HIV infection, ART duration, lower CD4/CD8 ratio at inclusion, lower nadir CD4, higher sCD14 and sCD163 values, living alone, dyslipidaemia, high blood pressure and diabetes (p < 0.05 for all). In multivariate analysis FIB-4 ≥ 1.3 was associated with sCD163 values ≥ 782 ng/mL [AdjOR 1.85, 95% CI [1.05; 3.33] p = 0.035], independently from CD4 count, ART duration, living alone, hepatitis C, high blood pressure and alcohol. Conclusions: The FIB-4 is a simple tool reliable for monocyte–macrophage activation in PWH, able to define subjects with higher risks of complications.