Until the late 1980' s, diffuse panbronchiolitis (DPB) (1) was recognized as a chronic small airway disease in the young-to middle-aged population with a poor prognosis in Japan. However, to date, most patients with DPBcan be improved and saved by long-term macrolides treatment. In this treatment, the 14-membered ring macrolides such as erythromycin (2) and clarithromycin (3, 4) are used. Considering it' s origin, this treatment was developed based on clinical evidence detected by a physician, however, it was not published as a case report. The clinical trials had been started in 1984 and were first reported in 1986 (5) and 1987 (6). Although long-term macrolide treatment was not accepted early, it is nowwell knownthat macrolides have anti-inflammatory mechanism (s) in addition to antibiotic effects. Clinical evidence and the recent progres