Cytokines in symptomatic asthma airways

Abstract

To determine whether cytokines are generated in vivo in subjects with asthma, we have measured cytokine (tumor necrosis factor [TNF], granulocyte-macrophage—colony-stimulating factor [GM—CSF], interleukin [IL]-1α, IL-1β, IL-2, IL-4, and IL-6) in the airways of subjects with symptomatic (N = 24) and asymptomatic (N = 9) asthma with immunoassays (GM-CSF, IL-1α, IL-1β, IL-2, ad IL-4) or bioassays (TNF and IL-6) and the polymerase chain reaction (IL-1β and TNF). Significant levels of TNF (578 ± 917 pg/ml versus 24 ± 29 pg/ml) ( p = 0.01), GM-CSF (24 ± 41 pg/ml versus <8 pg/ml) ( p = 0.02), and IL-6 (225 ± 327 pg/ml versus 7 ± 12 pg/ml) ( p = 0.01), but not IL-1α or IL-4, were detected in the bronchoalveolar lavage fluid (BALF) of patients with symptomatic compared with BALF of patients with asymptomatic asthma. Levels of IL-1β (266 ± 270 pg/ml versus <20 pg/ml) ( p = 0.001) and IL-2 (1.4 ± 2.8 ng/ml versus <0.3 ng/ml) ( p = 0.05) in BALF in patients with asymptomatic compared with that in BALF levels in patients with asymptomatic asthma suggested activation of alveolar macrophages and T cells. Thus, in episodes of asthma, several cytokines, including TNF, GM-CSF, IL-1β, IL-2, and IL-6 are detectable in BALF.