Abstract: Objective To investigate the changes of peripheral blood CD3⁺CD4^-CD8^-T cells （double negative T,DNT） and T lymphocyte subsets in patients with hepatitis B virus（HBV） infection. Methods The peripheral blood DNT cells and T lymphocyte subsets were detected by flow cytometry in 136 HBV cases including asymptomatic carriers（ASCs,n=33）,acute hepatitis B（AHB,n=28）,mild chronic hepatitis B（n=28）, moderate chronic hepatitis B（n=25）,severe chronic hepatitis B（n=22） and healthy persons（n=39）. Results The percentages of DNT cells in healthy persons and in patients with AHB were（4.82±3.43）% and（4.75±2.71）%,respectively,both of which were significantly lower than that in ASCs[（5.43±3.31）%,P<0.05];The percentage of DNT cells in patients with mild CHB was（7.97±4.12）%, significantly lower than in patients with severe CHB[（11.36±5.01）%,P<0.05],and the percentage of DNT cells in patients with moderate CHB was（8.41±4.93）%,also significantly lower than in patients with severe CHB（P<0.05）;There were no differences in percentages of T lymphocyte subsets among health persons,patients with acute hepatitis B and ASCs;The percentages of CD3⁺ and CD3⁺CD4⁺CD8^- cells decreased（P<0.05） and the percentage of CD3⁺CD4^-CD8⁺ cells increased （P<0.05） in patients with chronic severe hepatitis B. Conclusions The increase in peripheral blood DNT cells is associated with the chronicity of illness in patients with CHB.

Key words: Chronic hepatitis B, CD3+CD4-CD8-T cell, T lymphocyte subsets