Dynamic changes of regulatory T cells and their inhibitory molecules during antiviral treatment in patients with chronic hepatitis C

Abstract

Objective To investigate the dynamic changes of regulatory T cells (Treg) and the surface expression of programmed death (PD)-1 and the level of transforming growth factor (TGF)-β during antiviral treatment in patients with chronic hepatitis C (CHC). Methods Eighty-six CHC patients referred to the First Affiliated Hospital of Zhengzhou University from October 2012 to October 2013 were included, and all of them were administered with pegylated interferon α-2a and ribavirin. Thirty healthy controls were enrolled. The percentage of Treg cells, PD-1 expression and TGF-β level were analyzed by flow cytometry at baseline and at time of achieving rapid virological response (RVR), early viral virological (EVR), end-of-treatment virological response (ETVR) and sustained virological response (SVR), or not achieving SVR. Comparison between two groups was analyzed by t test. Results Among 86 CHC patients, the proportions of RVR, EVR, ETVR, and SVR at week 24 of follow-up were 29 cases, 67 cases, 79 cases and 67 cases, respectively. Percentage of Treg cells in CHC patients was much higher than that in healthy controls (10.31±5.61 vs 2.18±0.65, t=2.28, P<0.05). During antiviral therapy, percentages of Treg cells declined, not only in CHC patients with HCV genotype 1b (at baseline, RVR, EVR, and ETVR: 14.44±3.78, 11.01±1.79, 8.24±2.98, and 5.36±1.47, respectively), but also in those infected with HCV genotype 2a (at baseline, RVR, EVR, and ETVR: 12.34±2.82, 8.99±1.68, 7.53±2.96, and 4.79±1.23, respectively). Expressions of PD-1 and TGF-β also decreased. At baseline, the expressions of PD-1 in patients with SVR and without SVR were 29.11±14.65 and 37.73±11.65, respectively (t=2.15, P=0.04), and the levels of TGF-β were 41.20±18.96 and 56.75±14.42, respectively (t=2.66, P<0.01). At week 24, the expressions of PD-1 in patients with SVR and without SVR were 10.36±4.81 and 36.46±10.52, respectively (t=13.95, P<0.01), and the levels of TGF-β were 10.06±4.64 and 45.23±17.85, respectively (t=11.85, P<0.01). Conclusions Percentages of Treg cells and expressions of PD-1 and TGF-β decrease during antiviral treatment in CHC patients. Thus, it could be of assist to predict the treatment response by monitoring these parameters. Key words: Hepatitis C, chronic; Antiviral treatment; T-lymphocytes, regulatory; Programmed death-1; Transforming growth factor beta