Idiopathic pulmonary fibrosis(IPF), a subtype of IIP(idiopathic interstitial pneumonia), is a fatal disease with a 3-5 year median survival. Many attempts at treating this condition have failed to demonstrate a survival benefit in IPF. Recently Ziesche et al¹² reported the efficacy of IFN-γ for treating IPF but there is still some controversy. The aim of this study was to determine the efficacy of IFN-γ in patients with advanced IPF who had not been responsive to steroid and cytotoxic agents.

Nine patients with advanced IPF(age: 55.4±15.3 years, Male: Female=8:1) were enrolled. One year treatment regime with 2 million IU of IFN-γ administered subcutaneously three times a week, and low dose prednisolone(10-30 mg/d) was also used. In the case of a definite aggravation and serious side effects, the IFN-γ was discontinued. During the IFN-γ trial, a pulmonary function test and chest radiography were checked every three month throughout the study.

1) Among 9 patients, only 4 patients were able to complete the 12 month treatment with IFN-γ, and 5 patients died during the treatment period. 2) No improvement either in the respiratory symptoms or pulmonary functions were observed any of the patients, even in those who completed the 12 months trial of IFN-γ, 3) At the time of IFN-γ trial, the survivors who finished the IFN-γ treatment for 12 months had a higher oxygen level(81.3±2.8 vs. 67.4±8.4, P=0.024) and a better pulmonary function(FVC: 61.3±5.1% predicted vs. 45.7±12.3%, P=0.048, and DLco: 45.0±5.0% predicted vs. 30.8±11.2%, P=0.048) than the non-survivors.

Our data suggested that IFN-γ therapy was not effective in the patients with advanced IPF refractory compared with other therapeutic agents. Furthermore, these results suggest that severe impairment of the pulmonary function and hypoxemia during the IFN-γ therapy requires special attention.