We analyzed IL-5, IL-10, IL-1, IL-8, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α by enzyme-linked immunosorbent assay (or ELISA) kits (Bender MedSystems GmbM; Vienna, Austria). The detection limit of these assays was between 0.99 and pg/ml (1.45, 0.99, 1.06, 5, 0.99, and 3.83 pg/mL, respectively). All these assays have different coefficient of variations for intraassay (6.6%, 3.2%, 5.4%, 4.1%, 4.5%, and 6.9%, respectively) and interassay (6.8%, 5.6%, < 10%, 10.9%, 5.7%, and 7.4%, respectively). Moreover, we tested two types of lipidic mediators, PGE2 and LTC4, by enzyme-linked immunosorbent assay (Cayman Chemical Company; Ann Arbor, MI). Previously, to test lipid mediators, sputa were treated to remove protein and other contaminants that could interfere with the assay. In all subjects, mediators were measured in neat supernatants in duplicate. PGE2 assay shows a detection limit of 2 pg/mL, with a coefficient of variation for intraassay values of 5% and a coefficient of variation for interassay values of 4%, with a specificity of 100%. The LTC4 assay has a detection limit of 13 pg/mL, a specificity of 100%, and a coefficient of variation for intraassay values and interassay values of 8% and 10%, respectively.