Therapy naïve co-infected subjects had greater IFN-c producing CD8 + T-cells in response to HIV peptides compared to HCV mono-infected individuals [1.3960.37% vs 0.0260.0%, p,0.05], and HAART was associated with a significant reduction in the frequencies of these cells [1.3960.37% vs 0.3060.26%, p,0.05] (figure 2b). Although there was a trend for enhanced intra-hepatic CD8 + T-cells producing IFN-c in response to HCV peptides in therapy-naive co-infection compared to HCV mono-infection, this was not found to be statistically significant. HAART on the other hand, was associated with a significant reduction in HCV-specific, intra-hepatic CD8 + T-cells producing IFN-c [1.360.37% vs 0.0360.01%, p,0.05] (figure 2b).