Abstract： Objective To study the apoptosis of CD4 + T lymphocytes and the detection of immune function in patients with pulmonary tuberculosis and explore the clinical significance.Methods The mononuclear cells were separated from the blood of the tuberculosis patients or the healthy.The flow cytometry was used to measure the percentage of apoptotic CD4 + T lymphocytes,and the standard of T-lymphocyte subsets were detected by using SAP technology.The red cell immune function were determined by using yeast wreath way.Results The apoptosis rate of CD4 + T lymphocytes and CD8 + T lymphocyte was ( 15.882 ± 4.65 ) ％,and (27.69 ± 0.74) ％.The Immune complex positive rate ( 19.40 ± 0.58) ％ in patients with tuberculosis was significantly higher than those in controls ( P ＜ 0.01 ).C3b receptor positive rate in red blood cells was ( 17.73 ± 0.63 ) ％,( 46.48 ± 1.34 ) ％ in CD3 + T lymphocyte,( 28.12 ±0.69 ) ％ in CD4 + T lymphocyte,and the ratio of CD4/CD8 ( 1.0223 ± 0.09362) in the patients with tuberculosis was lower than the control group( P ＜ 0.01 ).There were certain relationships between the apoptosis rate of CD4 + T lymphocytes and the percentages of CD4 + T lymphocyte,the standard of T lymphocyte subsets and the red cell immune function.Conclusions The apoptosis rate of CD4 + T lympho,cytes in patients with tuberculosis were significantly higher than the healthy,which led to reducing the number of CD4 + T lymphocytes.There was positive correlation between red cell immunity and T-lymphocyte immunity,and the immunity in red cell and T- lymphocyte was lower than normal controls,which may be related to the immune pathogenesis of pulmonary tuberculosis.