[Imbalance of Th1/Th2 cytokines in patients with pulmonary tuberculosis]

To explore if there is an imbalance of Th1/Th2 cytokines in patients with pulmonary tuberculosis and its correlation with disease severity and treatment results.

The levels of serum IgE, IL-4 and IFN-gamma were measured in 100 healthy controls and 124 patients with pulmonary tuberculosis who were sputum positive for Mycobacterium tuberculosis before treatment. The cytokine levels were compared and their correlation with disease severity, sputum conversion after treatment, and treatment protocols were analyzed.

The serum levels of IgE, IL-4 and IFN-gamma were 1.048 +/- 0.496, 0.439 +/- 0.160 and 0.213 +/- 0.017 respectively in pulmonary tuberculosis, and 0.867 +/- 0.289, 0.421 +/- 0.024 and 0.224 +/- 0.005 respectively in the controls. The serum level of IL-4 was higher in patients with severe disease than that in patients with milder disease. Both IL-4 and IFN-gamma were significantly higher in cases receiving a second course of therapy than in patients receiving initial therapy. In patients who were sputum positive for Mycobacterium tuberculosis after two months of therapy, the serum level of IL-4 was higher but that of IFN-gamma was lower compared to those who became sputum negative for Mycobacterium tuberculosis after two months' treatment.

Patients with active pulmonary tuberculosis before antituberculous therapy showed lower expression of Th1 and higher expression of Th2 cytokines, and this cytokine profile was correlated with disease severity. Patients with lower serum IFN-gamma and higher IL-4 before treatment were less responsive to antituberculous therapy.