CD4+/CD25+ T cells suppress autologous CD4+/CD25- lymphocytes and secrete granzyme B during acute and chronic hepatitis C.

We aimed to verify whether CD4(+)/CD25(+) T cells suppress CD4(+) T cells and secrete Granzyme B (GZB) during acute and chronic hepatitis C (CHC) infection. We enrolled 50 subjects: 20 patients with CHC (Group A), 15 healthy individuals (Group B), 10 patients with acute hepatitis C later evolved to persistent infection (Group C) and five patients who resolved hepatitis C virus infection during acute phase (Group D). We analysed, on enrolled subjects CD4(+)/CD25(+) T cells and related GZB production as well as Annexin V activity. Patients from Groups A and C had higher frequency and function of peripheral Treg cells than healthy individuals. Groups A and C showed an increase in spot-forming colonies (SFCs) of GZB compared with Group B (P < 0.01, Mann-Whitney U-test). CD4(+)/CD25(+) T cells in Group D had a lower number of GZB SFCs compared with Groups A and C but higher number than Group B (P < 0.01 Mann-Whitney U-test). Annexin V production was higher in Groups A and C than B or D. Patients having acute and chronic hepatitis C have a higher Treg frequency and function in peripheral blood than healthy controls or those resolving the infection in acute phase secreting GZB, probably inducing apoptosis.