Endobronchial tuberculosis often complicates bronchostenosis, which can cause dyspnea due to an airway obstruction, and can be misdiagnosed as bronchial asthma or lung cancer. This study investigated the possible correlation between the interferon-γ(IFN-γ) and transforming growth factor-β(TGF-β) levels in the serum and bronchial washing fluid and the treatment results in endobronchial tuberculosis patients.

Sixteen patients, who were diagnosed as endobronchial tuberculosis using bronchoscopy, and 10 healthy control subjects were enrolled in this study. The IFN-γ and TGF-β levels were measured in the serum and bronchial washing fluid of 16 endobronchial tuberculosis patients before and after treatment using the ELISA method. The endobronchial tuberculosis patients were divided into those who showed bronchial fibrostenosis after treatment and those who did not.

The IFN-γ and TGF-β levels in the bronchial washing fluid in endobronchial tuberculosis patients were elevated comparing to the control (p < 0.05). After treatment, 7 of the 16 endobronchial tuberculosis patients showed bronchial fibrostenosis and the other 9 cases healed without this sequela. In the patients with fibrostenosis after treatment, the initial serum TGF-β level was lower than the patients without fibrostenosis after treatment (p < 0.05). Moreover, the serum TGF-β level after treatment further decreased comparing to the patients without fibrostenosis after treatment(p < 0.05). CONCLUSION: Elevated IFN-γ and TGF-β levels in the bronchial washing fluid in endobronchial tuberculosis patients are believed to be related to the pathogenesis of endobronchial tuberculosis. The decreased initial serum TGF-β level and the change in the serum TGF-β level after treatment are believed to be involved in bronchial fibrostenosis during the course of the disease.