Although similar frequencies of intra-hepatic lymphocytes were obtained in dual versus mono-infection, HAART-treated individuals showed a trend towards greater percentages of lymphocytes in their biopsies ( Figure 1a ). The percentage of intra-hepatic CD4 + T-cells was significantly reduced in dual infection [31.6%613.8 for HCV vs 6.5%62.9, for HCV/HIV therapy naïve, p,0.01], and was not associated with any improvement in HAART-treated individuals, as previously shown in the gut [15] (Figure 1b) . However, compared to HCV mono-infected individuals the percentage of intra-hepatic CD8 + T-cells was higher in both co-infected groups [33.8%65.5% for HCV vs 67.3%615.5% for HCV/HIV therapy naïve vs 59.5615.1% for HCV/HIV on HAART, p,0.01] (Figure 1b ).