Abstract: Objective To investigate the Toll-like receptor 3 (TLR3) expressions in peripheral blood mononuclear cells of chronic hepatitis B patients and explore its clinical significance. Methods The peripheral blood were collected from chronic hepatitis B patients and healthy volunteers, serum HBV DNA replication levels were detected by quantitative PCR; TLR3 mRNA and protein expression levels in peripheral blood mononuclear cells were detected by RT-PCR, flow cytometry and Western blot respectively; the serum levels of TNF-α and IFN-β were measured by ELISA. Results The TLR3 expression in peripheral blood mononuclear cells of chronic hepatitis B patients was significantly lower than that in healthy volunteers and related to the level of serum HBV DNA replication; the serum TNF-α，IFN-β concentrations of chronic hepatitis B patients were significantly lower than that in healthy volunteers and related to the level of serum HBV DNA replication level. Conclusion The TLR3 expression in peripheral blood mononuclear cells of chronic hepatitis B patients was associated with the proliferation of hepatitis B virus.

Key words: Key words: chronic hepatitis B, Toll-like receptors 3, peripheral blood mononuclear cells