Correlation between colonic regulatory T (Treg) frequency and both viral load and liver histopathology in treatment-naïve (TN) chronic hepatitis C virus (HCV)-infected patients. A significant (P < 0.0001) positive correlation between frequency of colonic Treg cells and viral load (r = 0.73, with 95% confidence interval [CI] = 0.6029–0.8264) in TN patients was detected (a). On the other hand, a significant negative correlation was detected between the frequency of colonic Treg in TN with METAVIR necro-inflammatory grade (P = 0.0001, r = −0.7586, with 95% CI = −0.8993 to −0.4759) and fibrosis stage (P = 0.0002, r = −0.7385 with 95% CI = −0.8901 to −0.4396) (b).