Fig. 5

iv-SIL does not influence the Treg compartment. Peripheral blood Treg and their expression of PD-1 were analyzed before (pre) and after (post) iv-SIL treatment by flow cytometry, as described in the “Methods” section. PBMC were stained using a combination of anti-CD3, anti-CD4, anti-CD127, anti-CD25, and anti-Foxp3, and Treg defined as CD4⁺CD127⁻CD25^hiFoxp3⁺. Almost all CD4⁺CD127⁻CD25^hi cells (94 %) expressed Foxp3. a Overall analysis of the frequency of circulating Treg and the overall analysis of the Foxp3 (MFI) and PD-1 (% and MFI) expression by Treg. b Correlation between PD-1 expression on Treg (% and MFI) and HCV-RNA and AST