Fig. 3.

IFN-α and ribavirin therapy rapidly increases the frequency of Treg in the livers of many HCV-infected patients. (A) Liver CD4⁺ CD25⁺ FoxP3⁺ Treg frequencies relative to CD4⁺ and CD8⁺ T cells at baseline and 4 weeks after starting antiviral therapy (n = 22). The findings are grouped as “decreased” or “increased” on the basis of the difference between the Treg frequencies before and during therapy, irrespective of the magnitude of the shifts of liver Treg relative to CD4⁺ or CD8⁺ T cells. (B) Treg subsets from 22 chronic HCV patients phenotyped by flow cytometry and classified as naive, central memory (CM), effector memory (EM), or terminally differentiated (Term) based on CD45RO and CD62L expression. All changes in the frequencies of specific memory populations determined prior to and during therapy were not significant.