The Reduction in CD8+PD-1+ T Cells in Liver Histological Tissue is Related to Pegylated IFN-α Therapy Outcomes in Chronic Hepatitis B Patients

Background and Aim: Antiviral therapy is recommended for patients with immune-active chronic hepatitis B (CHB) to decrease the risk of liver-related complications. However, the outcomes of the pegylated IFN-α (PEG-IFN-α) therapy vary among CHB patients. We aimed to identify factors that can influence the outcomes in CHB patients who received antiviral PEG-IFN-α monotherapy. Methods: Thirty-two CHB patients who received PEG-IFN-α monotherapy were enrolled in this study. All of the patients underwent two liver biopsies at baseline and 6 months after the initiation of the therapy. CD8+ T cells, CD4+ T cells, CD68+ mononuclear cells, and PD-1 levels in the 64 liver biopsy specimens were examined via immunofluorescence. Results: The overall median frequency of CD8+ T cells in the liver tissues of 32 CHB patients significantly decreased at 6 months after the therapy initiation (p < 0.01). In the FIER (fibrosis and inflammation response with HBeAg seroconversion) group, CD8+PD-1+ T cells significantly decreased at 6 months (p < 0.05), while CD8+PD-1- T cells had no significant difference. On the contrary, in the FIENR (no fibrosis and inflammation response and HBeAg seroconversion) group, CD8+PD-1- T cells significantly decreased after 6 months of PEG-IFN-α treatment (p < 0.05), while CD8+PD-1+ T cells had no significant difference. In addition, the levels of CD68+ mononuclear cells in the FIER group showed an overall increasing trend after treatment (p < 0.05). Conclusions: The changes in the levels of CD8+PD-1+ T cells and CD68+ mononuclear cells may be related to the response to PEG-IFN-α therapy.