Expression Of PD-1 On Peripheral Blood T Cells During Different Immune Status In Patients With Chronic Hepatitis B

Objective: To study the expression of PD-1 on peripheral blood CD4~+ and CD8~+ T cells in patients with chronic hepatitis B virus infection during different immune status, and to explore the relationship between the expression of PD-1, serum levels of HBV DNA and serum ALT levels.Methods: A total of 111 CHB patients were enrolled for the study and divided into three groups according to different immune status, 24 patients in immuno-tolerance phase (HBeAg positive, HBV-DNA>107copy/ml, normal levels of ALT), 64 patients in immuno-reactive phase (HBeAg positive, HBV-DNA positive, increased levels of ALT), 23 patients in HBeAg-negative CHB group (HBeAg negative, HBV-DNA positive, increased levels of ALT), and 11 healthy blood donors were selected as control. The proportion of peripheral blood CD4~+, CD8~+T cells expressed PD-1 were assessed by flow cytometry. Serum HBV DNA load was determined by real-time fluorescent quantitative polymerase chain reaction (PCR) and serum ALT levels were examined simultaneously.Result: The proportion of peripheral blood CD4~+, CD8~+T cells expressed PD-1 in the immuno-reactive group and HBeAg-negative CHB group was significantly higher than the immuno-tolerance group and the control group (P<0.05). Furthermore, the proportion of CD8~+T cells expressed PD-1 in HBeAg-negative CHB group was significantly higher than the immuno-reactive phase group (P<0.05).Correlation analysis showed the proportion of peripheral blood CD4~+, CD8~+T cells expressed PD-1 was either correlated with HBV DNA loads or serum ALT levels in CHB patients during different immune status.Conclusion: The expression of PD-1 on peripheral blood T cells were closely related to the immune status. The liver inflammation,but not the serum HBV DNA loads, influences the expression of PD-1 on peripheral blood T cells.