Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

STUDY OBJECTIVES: To investigate whether differing airway interleukin (IL)-18 levels may be implicated in the pathogenesis of asthma and sarcoidosis. SETTING: University teaching hospital. PATIENTS AND METHODS: IL-18 levels were measured in BAL fluid and in the supernatant of lipopolysaccharide (LPS)-stimulated alveolar macrophages obtained by BAL from 15 patients with sarcoidosis, 11 patients with asthma, and 13 healthy subjects. We also examined the relationship between IL-18 levels and macrophage and lymphocyte concentrations in BAL fluid. IL-18 was measured using an in-house enzyme-linked immunosorbent assay. RESULTS: IL-18 levels were significantly lower in BAL fluid from patients with asthma (median, 0.0 pg/mL; interquartile range, 0.0 to 0.0 pg/mL) compared to patients with sarcoidosis (median, 222.0 pg/10(6); interquartile range, 110 to 340 pg/mL; p = 0.009, Mann Whitney rank-sum test) and healthy control subjects (median, 162 pg/mL; interquartile range, 38 to 203 pg/mL; p = 0.025, Mann Whitney rank-sum test). Individual analyses comparing IL-18 levels with BAL macrophage counts, and IL-18 with lymphocyte counts in the three groups showed no correlation between these indexes. The mean levels of IL-18 in unstimulated macrophage supernatants were 410 pg/10(6) cells for patients with asthma, 723.4 pg/10(6) cells for patients with sarcoidosis, and 734.8 pg/10(6) cells for healthy control subjects (p > 0.05). Stimulated macrophages from patients with sarcoidosis responded with increasing amounts of IL-18 at lower doses of LPS than macrophages from healthy control subjects or patients with asthma. CONCLUSION: Our findings suggest that inherently low levels of IL-18 may be associated with the pathogenesis of asthmatic airway inflammation.


Journal article



Publication Date





1421 - 1426


Adult, Asthma, Bronchoalveolar Lavage Fluid, Cell Count, Cells, Cultured, Enzyme-Linked Immunosorbent Assay, Humans, Interleukin-18, Lymphocytes, Macrophages, Macrophages, Alveolar, Middle Aged, Sarcoidosis, Pulmonary