T cell mediated immunity is important in the defense mechanism of tuberculosis. Since γδ T cell receptor was found to react with 65 kD heat shock protein of M. tuberculosis, there have been some reports on the role of γδ T cells in the defense against M. tuberculosis. But until now, the role of the γδ T cells in tuberculosis is not clear.

We therefore measured the percentage of γδ T cells of peripheral blood by flowcytometry before and after stimulation with Con-A, PPD and H37Ra lysate and compared between tuberculosis patients and healthy controls.

γδ T cells of pheripheral blood in pulmonary tuberculosis patients was 7.5 ±5.2%, showing no difference compared with healthy control(10.0±4.8%). But IL-2R(+) γδ T cells were higher in tuberculosis compared with healthy control(4.8±5.1% vs. 1.8 ±2.8%). After stimulation with PPD or Con-A, the percentage of γδ T cells showed no significant change, but IL-2R(+) γδ T cells increased significantly in both tuberculosis(17.9±13.4%, 57.6±20.2% respectively) and healthy control group(11.5±9.1%, 80.8±9.3%). After stimulation with H37Ra lysate, percentage of γδ T cells showed increasing tendency in healthy control group, but it was not statistically significant.

In this study, we could not demonstrate the role γδ T cells in the peripheral blood of pulmonary tuberculosis. It is suggested that further studies will be needed in the regional sites of M. tuberculosis infection.