Immunological recovery in T-cell activation after sustained virologic response among HIV positive and HIV negative chronic Hepatitis C patients

Background Rapid decreases in activated CD4+and CD8+(HLA-DR+and CD38+co-expressed) T-lymphocytes have been described within 1-2weeks of initiating direct-acting antiviral (DAA) therapy among chronic Hepatitis C (CHC) patients. However, it is not known whether these changes are maintained past sustained virologic response (SVR), particularly in those who are HIV/HCV-coinfected. Methods We investigated the changes in immune parameters of T-lymphocytes from pre-DAA therapy to post-SVR among HIV negative and HIV positive patients with CHC. Repeated measurements of activated CD4+ and CD8+T cells were analyzed by flow cytometry at pre-DAA therapy, DAA therapy, end of treatment, SVR, and post-SVR. A general linear model for repeated measurements was used to estimate the mean outcome at each timepoint and change between timepoints. Results HCV-monoinfected (n = 161) and HIV/HCV-coinfected (n = 59) patients who achieved SVR with DAA therapy were predominately middle aged, male, black, and non-cirrhotic. At pre-DAA therapy, HCV-monoinfected patients had significantly higher CD4+T cells and CD4+:CD8+T-cell ratio, while significantly lower CD8+and activated CD4+and CD8+T cells compared to HIV/HCV-coinfected patients (p < 0.0001). HCV-monoinfected and HIV/HCV-coinfected patients had a significant mean decrease from pre-DAA therapy to post-SVR year 1 for activated CD4+(HCV-monoinfected: 4.8-3.9%, p < 0.0001; HIV/HCV-coinfected: 6.6-4.5%, p < 0.0001) and activated CD8+T cells (HCV-monoinfected V: 13.8-11.8%, p = 0.0002; HIV/HCV-coinfected: 18.0-12.4%, p < 0.0001). Conclusion This longitudinal study showed CHC patients treated with DAA therapy had continued decrease of T-lymphocytes from start of DAA therapy to after achievement of SVR suggesting improvement as HCV clearance normalizes activated T-cell phenotype.