Abstract:Objective To study the expression of PD-1/PD-L1 on cytotoxic T lymphocytes in the peripheral blood of patients with chronic hepatitis B and its correlation with disease severity. Methods A total of 90 cases of chronic hepatitis B patients and 82 cases of healthy subjects were respectively enrolled into the chronic hepatitis B group and the healthy control group. Expressions of PD-1 and PD-L1 on cytotoxic T lymphocytes in the peripheral blood and serum biochemical indices were determined. Results Expressions of PD-1 and PD-L1 on cytotoxic T lymphocytes in the peripheral blood of the chronic hepatitis B group were significantly higher than those in the healthy control group. Patients with higher HBV load also had a higher expression of PD-1 and PD-L1 on cytotoxic T lymphocytes in the peripheral blood. And serum ALT, AST, IL-6, IL-8 contents of chronic hepatitis B groups were significantly higher than those in healthy control group and positively correlated with PD-1 and PD-L1 expression on cytotoxic T lymphocytes in the peripheral blood. Conclusions The expression of PD-1 and PD-L1 on cytotoxic T lymphocytes in the peripheral blood of patients with chronic hepatitis B significantly elevates and correlates with the degree of liver injury and the degree of inflammation.