Decreased in vitro interferon-γ production in patients with cavitary tuberculosis on chest radiography

Interferon (IFN)-γ expression is altered in pulmonary lesions, such as cavities and granulomas. However, the exact association between patterns on chest radiography and IFN-γ responses are unclear. The purpose of this study was to determine the IFN-γ response in patients with tuberculosis and to correlate the pulmonary lesions with the IFN-γ responses. We enrolled 78 patients with tuberculosis, as diagnosed with initial positive results for acid-fast bacilli in the sputum and final positive cultures for Mycobacterium tuberculosis. Cell cultures of stimulated peripheral blood mononuclear cells were performed. The supernatants were analyzed for the IFN-γ response and the results statistically analyzed. The patients' chest radiographs were examined for fibronodules, masses, pleural effusion, cavities, and the severity of parenchymal involvement. IFN-γ responses were lower in patients with cavities on chest radiography than in those without cavities (403.306±397.048 vs 698.154±593.436 pg/ml, P < 0.05). IFN-γ responses were also lower in patients with masses on chest radiography than in those without masses (186.345±200.724 vs 583.950±528.295 pg/ml, P < 0.05). After regression analysis, the presence of a cavity was the only factor predictive of a decreased IFN-γ response. We conclude that only chest radiographic pattern correlated with the IFN-γ response was cavity formation. The administration of pharmacological IFN-γ in tuberculosis patients with cavity may be considered.