Background and Aim: The better understanding of immunopathologic mechanism of tuberculosis (TB) is necessary for the production of new vaccines and adjunctive immunomodulator drugs. Intended to this object, the following study including the measurement of serum concentrations of Th1 (Interferon (IFN)-y and interkeukin (IL)-2 and Th2 cytokines(IL-4AND IL-10 ) in patients with sputum smear-positive pulmonary TB and comparisons of them with PPpositive healthy persons, was designed.

Materials and Methods: The HIV-negative patients that had sputum smear-positive pulmonary TB as defined WHO criteria and hospitalized in the infectious diseases ward of Imam Khomeini hospital or referred to health care centers in the south of Tehran, were included in the study. The PPD-positive healthy persons who were close contacts with pulmonary TB patients, were considered as control group.

Results: In this research 34 active pulmonary TB patients (including17men and 17 woman)and 23 healthy persons with PPD skin test results  or = 10mm (including 12men and 11 woman) were studied. The mean ages of the patients and the healthy persons were 73 and 41 years and 74 and 27 years, respectively. The mean serum IFN-Y concentration was significantly higher in TB patients but the mean serum IL-2 IL-4and IL-10 concentrations were significantly higher in healthy persons. The com parison of the mean serum levels of these cytokines before and during treatment (about 2 months after starting treatment) showed that the amounts of IFN-y and IL4 were increased and the amounts of IL2 and IL-10 were decreased but only the changes of IL-10 were statistically significant. There were no effect on the cytokine changes before and during treatment by age and gender of the patients.

Conclusion: The results of the study of serum Th1 and Th2 cytokines in pulmonary TB patients were different in comparison with the results of the studies of peripheral blood mononuclear cells (PBMCs) stimulated with M.tuberculosis antigens. SO, the simultaneous measurement of them in serum, pleural fluid, BAL fluid and the medium culture of PBMCs stimulated with the antigens is recommended.