Objective:To study the probable mechanism of HBV effect on cellular immune system in human body by detecting the quantity and function of CD4~+T and CD8+T cells in peripheral blood and liver tisues.Methods:1)The quantity of CD4~+T and CD8~+T cells in peripheral blood was detected by flow cytometry(FCM) in 36 patients with hepatitis B and 20 cases of controls;2)The expressions of HBsAg and HBcAg were detected by streptavidin-peroxidase immunohistochemistry(SP).50 cases of positive HBsAg and(or)HBcAg were selected as HBV(+) group

and 10 cases of negative HBsAg and HBcAg in liver tissue and blood serum were selected as HBV(-) group.The expressions of CD4

CD8

CD25 in liver tissues were detected in the two groups.Results:1)The quantity of CD4~+T cells and the ratio of CD4~+T/CD8~+T in peripheral blood of patients was significantly lower than those in controls;the quantity of CD8~+T cells was considerably higher than that in controls.(2)T lymphoid cell infiltrates in the liver were most gathered in the lobules and the portal tract.The densities of CD8~+T cells were higher in lobules and portal tracts than CD4~+T cells.The quantity of CD8+T and CD4~+T cells in the liver tissues of HBV positive group showed significant difference from the liver tissues of HBV negative group(P~b<0.05).The quantity of CD25~+T related to ability of immunity in HBV positive group was less than HBV negative group

but no significant statistical difference was found between two groups.Conclusion:The T lymphoid subsets of peripheral blood mononuclear cells and the liver tissues of patients infected with HBV are disordered and the activity of T cells decreases

which suggests a possible weakened immunity.