Longitudinal assessment of multiple immunological and inflammatory parameters during successful DAA therapy in HCV monoinfected and HIV/HCV coinfected subjects

In the direct-acting antiviral (DAA) era, it is important to understand the immunological changes after HCV eradication in HCV monoinfected (mHCV) and in HIV/HCV coinfected (HIV/HCV) patients. In this study, we analyzed sub-populations of monocytes, dendritic cells (DCs), T-lymphocytes and inflammatory biomarkers following initiation of DAA in 15 mHCV and 16 HIV/HCV patients on effective antiretroviral therapy at baseline and after sustained virological response at 12 weeks (SVR12). Fifteen age- and sex-matched healthy donors (HD) were enrolled as a control group. Activated CD4+ and CD8+ T-lymphocytes, mDCs, pDCs, MDC8 and classical, non-classical and intermediate monocytes were detected using flow cytometry. IP-10, sCD163 and sCD14 were assessed by ELISA while matrix metalloproteinase-2 (MMP-2) was measured by zymography. At baseline, increased levels of IP-10, sCD163 and MMP-2 were found in both HIV/HCV and mHCV patients compared to HD, whereas sCD14 increased only in HIV/HCV patients. After therapy, IP-10, sCD163 and sCD14 decreased, whereas MMP-2 persistently elevated. At baseline, activated CD8+ T-cells were high in HIV/HCV and mHCV patients compared to HD, with a decrease at SVR12 only in HIV/HCV patients. Activated CD4+ T-cells were higher in HIV/HCV patients without modification after DAAs therapy. These results suggest complex interactions between both viruses and the immune system, which are only partially reversed by DAA treatment.