TY - JOUR T1 - Interleukin-18 production and pulmonary function in COPD JF - European Respiratory Journal JO - Eur Respir J SP - 287 LP - 297 DO - 10.1183/09031936.00019207 VL - 31 IS - 2 AU - H. Imaoka AU - T. Hoshino AU - S. Takei AU - T. Kinoshita AU - M. Okamoto AU - T. Kawayama AU - S. Kato AU - H. Iwasaki AU - K. Watanabe AU - H. Aizawa Y1 - 2008/02/01 UR - http://erj.ersjournals.com/content/31/2/287.abstract N2 - Interleukin (IL)-18 production and pulmonary function were evaluated in patients with chronic obstructive pulmonary disease (COPD) in order to determine the role of IL-18 in COPD. Immunohistochemical techniques were used to examine IL-18 production in the lungs of patients with very severe COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage IV, n = 16), smokers (n = 27) and nonsmokers (n = 23). Serum cytokine levels and pulmonary function were analysed in patients with GOLD stage I–IV COPD (n = 62), smokers (n = 34) and nonsmokers (n = 47). Persistent and severe small airway inflammation was observed in the lungs of ex-smokers with very severe COPD. IL-18 proteins were strongly expressed in alveolar macrophages, CD8+ T-cells, and both the bronchiolar and alveolar epithelia in the lungs of COPD patients. Serum levels of IL-18 in COPD patients and smokers were significantly higher than those in nonsmokers. Moreover, serum levels of IL-18 in patients with GOLD stage III and IV COPD were significantly higher than in smokers and nonsmokers. There was a significant negative correlation between serum IL-18 level and the predicted forced expiratory volume in one second in patients with COPD. In contrast, serum levels of IL-4, IL-13 and interferon-γ were not significantly increased in any of the three groups. In conclusion, overproduction of interleukin-18 in the lungs may be involved in the pathogenesis of chronic obstructive pulmonary disease. ER -