Increased levels of interleukin 27 in patients with early clinical stages of non-small cell lung cancer

INTRODUCTION Interleukin 27 (IL-27) is a cytokine secreted mostly by antigen-presenting cells. It is important for the immune polarization of T helper-1 (Th1) cells, and its role in interstitial lung diseases (ILDs) and lung cancer has been investigated. Objectives We assessed IL-27 expression in the lower airways of patients with selected ILDs and early-stage non-small cell lung cancer (NSCLC). Patients and methods IL-27 concentrations were examined by an enzyme-linked immunosorbent assay in bronchoalveolar lavage (BAL) fluid supernatants collected from patients with pulmonary sarcoidosis (PS; n = 30), extrinsic allergic alveolitis (EAA; n = 14), idiopathic pulmonary fibrosis (IPF; n = 12), nonspecific interstitial pneumonia (NSIP; n = 14), and NSCLC stages I to IIa (n = 16) with peripheral localization, and in controls (n = 14). The major lymphocyte subsets in BAL fluid were phenotyped, and intracellular IL-27 expression was evaluated by flow cytometry. Results IL-27 concentrations in BAL fluid supernatants were significantly increased in Th1-mediated conditions such as EAA and PS, but not in IPF or NSIP. The highest IL-27 levels (median [SEM], 16.9 [17.5] pg/ml) were reported for NCSLC, and the lowest-for controls (median [SEM], 0.4 [0.2] pg/ml). IL-27 was undetectable in corticosteroid-treated patients with PS. Both CD4(+) and CD8(+) lymphocytes were positive for IL-27; they were a possible local source of IL-27 because the cytokine levels were positively significantly correlated with the total number of lymphocytes, including CD4(+) cells. Conclusions Our results support the Th1-linked activity of IL-27 in ILDs. Early-stage NSCLC is characterized by high IL-27 expression in the lower airways. IL-27 is produced by a high percentage of CD4(+) and CD8(+) cells in BAL fluid, both in patients and controls.