Increased Levels of miR-155 are Related to Higher T-Cell Activation in the Peripheral Blood of Patients with Chronic Hepatitis B.

Objectives: MicroRNA-155 (miR-155) is an important regulator of immune responses in humans. However, its role in T-cell activation in hepatitis B virus (HBV) infection remains unclear.
Materials and Methods: Eighty-one patients with chronic hepatitis B (CHB), 77 HBV carriers, and 51 healthy controls were recruited. HBV DNA and serologic tests were carried out for each subject. Levels of miR-155 in peripheral blood were detected by quantitative reverse transcription/polymerase chain reaction. Immune activation of T-cells was determined by detection of surface molecules CD38 and HLA-DR using flow cytometry.
Results: We found higher miR-155 levels in CD4 ⁺ and CD8 ⁺ T-cells of CHB patients than HBV carriers or healthy controls (p < 0.01), moreover, miR-155 levels in the CD8 ⁺ T-cells of HBV carriers were higher than in healthy controls (p < 0.01). Furthermore, immune activation of CD4 ⁺ and CD8 ⁺ T-cells in CHB patients was much higher than in healthy controls (p < 0.01).
Conclusion: Our findings suggest that miR-155 expression positively correlates with T-cell activation, especially in CHB patients, and is a potential biomarker for immune activation and disease progression in HBV infection.