Reduced population of CD4+,CD154+ T cell subset in patients with active pulmonary tuberculosis

Objective To study population frequencies of CD4+,CD154+ T cell subset in patients with pulmonary tuberculosis and controls with positive PPD reaction. Methods Flow cytometry was used to detect the CD4+,CD154+ T cell subset, the population frequen-cies in patients with pulmonary tuberculosis and controls were compared. Results The expression level of CD154 was higher when PE-la-beled CD154 antibody was added during stimulation period, compared with CD154 labeling after stimulation(1.51±0. 36/0. 40±0. 13, P <0.05). The CD154+ cells were not detectable in fresh isolated CD4+ T cells, but significantly increased after stimulation with specific anti-gens. The population of CD4+, CD154+ T cell subset was significantly reduced in patients with active pulmonary tuberculosis, compared with healthy controls with PPD positive reaction(0. 72±0. 32/1.65±0. 76, P <0. 01). Conclusions The population of CD4± ,CD154± T cell subset was significantly reduced in patients with active pulmonary tuberculosis, which indicated that it may play an important role in the de-velopment of tuberculosis. Key words: Tuberculosis,pulmonary ;  CD4-positive T-lymphocytes ;  CD40 ligand ;  T-lympheytes ;